Report ITU-R M.2478-0 (09/2019)
Spectrum needs for the amateur service in the frequency band 50-54 MHz in Region 1
and sharing with mobile, fixed, radiolocation and broadcasting services
M Series
Mobile, radiodetermination, amateur
and related satellite services
ii Rep. ITU-R M.2478-0
Foreword
The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-
frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit
of frequency range on the basis of which Recommendations are adopted.
The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional
Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups.
Policy on Intellectual Property Right (IPR)
ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Resolution ITU-
R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available
from http://www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for
ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found.
Series of ITU-R Reports
(Also available online at http://www.itu.int/publ/R-REP/en)
Series Title
BO Satellite delivery
BR Recording for production, archival and play-out; film for television
BS Broadcasting service (sound)
BT Broadcasting service (television)
F Fixed service
M Mobile, radiodetermination, amateur and related satellite services
P Radiowave propagation
RA Radio astronomy
RS Remote sensing systems
S Fixed-satellite service
SA Space applications and meteorology
SF Frequency sharing and coordination between fixed-satellite and fixed service systems
SM Spectrum management
Note: This ITU-R Report was approved in English by the Study Group under the procedure detailed in
Resolution ITU-R 1.
Electronic Publication
Geneva, 2019
ITU 2019
All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU.
Rep. ITU-R M.2478-0 1
REPORT ITU-R M.2478-0
Spectrum needs for the amateur service in the frequency band 50-54 MHz in
Region 1 and sharing with mobile, fixed, radiolocation and broadcasting services
(2019)
TABLE OF CONTENTS
Page
1 Introduction .................................................................................................................... 7
1.1 Background to this Report .................................................................................. 7
1.2 Structure of this Report ....................................................................................... 8
1.3 Geographic considerations .................................................................................. 8
2 Current usage of the 50-54 MHz frequency band in Region 1 ....................................... 8
2.1 The amateur service ............................................................................................ 8
2.2 The radiolocation service .................................................................................... 9
2.3 The broadcasting service .................................................................................... 9
2.4 The fixed and mobile services ............................................................................ 10
2.5 Inter-regional sharing between services ............................................................. 11
2.6 Others applications in the 50-54 MHz frequency band ...................................... 11
3 Spectrum needs for the amateur service in Region 1 ..................................................... 11
3.1 General considerations ........................................................................................ 11
3.2 Background on current usage on national basis in Region 1 .............................. 11
3.3 Other envisaged applications .............................................................................. 12
3.4 Designated application categories to be taken into account in spectrum needs
estimation ............................................................................................................ 12
3.5 Application based assessment of spectrum needs .............................................. 13
3.6 Study 1 based on spectrum occupancy and contest log data analysis ................ 13
3.7 Study based on estimations and long term experience ....................................... 16
3.8 Reasons for differences between the studies ...................................................... 18
3.9 Summary of spectrum needs from the studies .................................................... 18
3.10 Status of possible allocation ............................................................................... 20
Page
2 Rep. ITU-R M.2478-0
4 Characteristics of amateur stations for sharing studies .................................................. 20
4.1 Global characteristics .......................................................................................... 20
4.2 Specific Region 1 characteristics ........................................................................ 20
4.3 Antenna type and polarization ............................................................................ 21
4.4 Propagation Factors ............................................................................................ 22
5 Sharing with the mobile service ..................................................................................... 22
5.1 System parameters of the mobile service ........................................................... 23
5.2 Minimum coupling loss calculations .................................................................. 24
5.3 Radio Interference coverage mapping ................................................................ 28
5.4 A Monte-Carlo simulation of amateur service versus mobile service using the
P.2001-2 propagation model ............................................................................... 28
5.5 A Monte-Carlo simulation using the CEPT SEAMCAT simulation software ... 30
5.6 Sharing possibilities ............................................................................................ 31
5.7 Summary of conclusions ..................................................................................... 33
6 Sharing with the fixed service ........................................................................................ 33
7 Sharing with the radiolocation service ........................................................................... 33
7.1 Background ......................................................................................................... 33
7.2 Study details ........................................................................................................ 34
7.3 Study results ........................................................................................................ 34
7.4 Regulatory aspects .............................................................................................. 34
8 Sharing with the broadcasting service ............................................................................ 34
8.1 Sharing study details ........................................................................................... 34
8.2 Study 1 description ............................................................................................. 34
8.3 Study 1 results ..................................................................................................... 35
8.4 Study 2 description ............................................................................................. 35
8.5 Study 2 results ..................................................................................................... 35
8.6 Study 3 description ............................................................................................. 36
8.7 Study 3 results ..................................................................................................... 37
8.8 Summary of study results ................................................................................... 37
9 Mitigation Factors........................................................................................................... 38
10 Conclusion of the Report ................................................................................................ 39
Rep. ITU-R M.2478-0 3
Page
10.1 Study components ............................................................................................... 39
10.2 Spectrum needs ................................................................................................... 39
10.3 Sharing with the mobile service ......................................................................... 39
10.4 Sharing with the broadcasting service ................................................................ 39
10.5 Sharing with the radiolocation service ............................................................... 40
10.6 Status of allocation ............................................................................................. 40
Annex 1 – Spectrum needs and associated information .......................................................... 40
A1.1 Introduction ......................................................................................................... 40
A1.2 Regulatory history .............................................................................................. 40
A1.3 Current and future regulatory issues ................................................................... 41
A1.4 General information about the amateur service .................................................. 41
A1.5 CEPT Provisions in Region 1 ............................................................................. 41
A1.6 Article 5 – VHF Amateur Spectrum Shortfall in Region 1 ................................ 41
A1.7 Detailed 50 MHz band usage and propagation mechanisms relevant to the
Amateur Service ................................................................................................. 42
A1.8 Propagation ......................................................................................................... 42
A1.9 50-52 MHz band usage ....................................................................................... 44
A1.10 52-54 MHz band usage ....................................................................................... 45
A1.11 Power flux density .............................................................................................. 46
A1.12 Station identification by call-sign ....................................................................... 46
A1.13 Listen before talk (transmit) ............................................................................... 46
A1.14 Band Availability ................................................................................................ 47
Annex 2 – Statistics – number of amateur stations and density ............................................... 47
Annex 3 – An application-based approach to calculation of spectrum needs ......................... 49
A3.1 Principles for calculating spectrum needs .......................................................... 49
A3.2 Geographic Parameters ....................................................................................... 49
A3.3 Traffic Parameters .............................................................................................. 49
A3.4 Technology ......................................................................................................... 50
A3.5 Calculations ........................................................................................................ 50
A3.6 Results of application-based approach ............................................................... 51
Annex 4 – Another analysis of amateur band occupancy ........................................................ 51
4 Rep. ITU-R M.2478-0
Page
Annex 5 – Amateur service sharing with (analogue television) broadcasting service ............ 55
A5.1 Introduction ......................................................................................................... 55
A5.2 Method ................................................................................................................ 56
A5.3 Variables for the unwanted amateur station signal ............................................. 57
A5.4 Variables for the wanted TV signal .................................................................... 58
A5.5 The calculation .................................................................................................... 58
A5.6 Sharing scenario .................................................................................................. 59
A5.7 An alternative approach ...................................................................................... 59
A5.8 Summary and conclusions .................................................................................. 60
Annex 6 – A Monte-Carlo simulation study of compatibility between the analogue TV
broadcast service and the amateur service ...................................................................... 61
A6.1 Introduction and summary .................................................................................. 61
A6.2 Study details ........................................................................................................ 61
A6.3 The major metropolitan area study ..................................................................... 61
A6.4 The rural centre study ......................................................................................... 62
Annex 7 – Amateur service stations interference to television receivers of the broadcasting
service in the band 50-54 MHz....................................................................................... 69
A7.1 Introduction ......................................................................................................... 69
A7.2 Working Assumptions ........................................................................................ 69
A7.3 Calculation results .............................................................................................. 72
A7.4 Findings and Proposals ....................................................................................... 81
Annex 8 – Information concerning current and past sharing arrangements between the
amateur service and other services in the 50-52 MHz frequency band .......................... 82
A8.1 Introduction ......................................................................................................... 82
A8.2 Sharing scenarios ................................................................................................ 82
A8.3 Country information ........................................................................................... 82
A8.4 Summary ............................................................................................................. 87
Annex 9 – Background information on TV in Region 1.......................................................... 89
A9.1 Broadcasting plans .............................................................................................. 89
A9.2 The 2016 Situation .............................................................................................. 89
A9.3 Digital Terrestrial Television Broadcasting in Band 1: 47-68 MHz .................. 90
A9.4 Analogue Television Broadcasting in Band 1: 47-68 MHz ................................ 91
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Page
Annex 10 – A Monte-Carlo simulation of sharing with the mobile service ............................ 91
A10.1 Introduction ......................................................................................................... 91
A10.2 Background ......................................................................................................... 91
A10.3 The study scenarios and basic system parameters .............................................. 92
A10.4 Operational considerations ................................................................................. 96
A10.5 Estimating the service range of the tactical links ............................................... 97
A10.6 Range of the amateur service links assumed in this study .................................. 97
A10.7 Results of the simulations ................................................................................... 98
A10.8 Conclusion .......................................................................................................... 99
Annex 11 – Minimum Coupling Loss sharing study between amateur radio stations and
governmental mobile systems ........................................................................................ 99
A11.1 Propagation model .............................................................................................. 100
A11.2 Global approach .................................................................................................. 100
A11.3 Protection criterion and ambient noise figure ..................................................... 100
A11.4 Radiated power for co- and adjacent channels ................................................... 101
A11.5 Determination of minimum path attenuation ...................................................... 101
A11.6 MCL Results ....................................................................................................... 102
Attachment 1 to Annex 11 – Amateur radio transmission mask ............................................ 102
Attachment 2 to Annex 11 – Propagation scenarios for MCL calculations ............................. 105
Attachment 3 to Annex 11 – Radiated Power for Co-adjacent and spurious domain ............ 109
Attachment 4 to Annex 11 – Minimum required path loss ..................................................... 111
Annex 12 – Radio Interference coverage mapping .................................................................. 112
A12.1 Determination of the interference level .............................................................. 113
A12.2 Simulation results ............................................................................................... 113
A12.3 Results for Yverdon-Les-Bains Switzerland ...................................................... 113
A12.4 Results for Aachen (Germany) ........................................................................... 116
A12.5 Results for Faux d’Enson (Swiss/French border) ............................................... 118
A12.6 Results for Vallon-En-Sully (France) ................................................................. 121
Annex 13 – Amateur service vs. Mobile service Monte-Carlo study details .......................... 123
A13.1 Determination of the interference level .............................................................. 123
A13.2 Amateur service characteristics .......................................................................... 123
6 Rep. ITU-R M.2478-0
Page
A13.3 Propagation Model .............................................................................................. 123
A13.4 Protection criterion and ambient noise figure ..................................................... 124
A13.5 Amateurs Emission masks/Mobile reception mask ............................................ 124
A13.6 SSB Case ............................................................................................................ 124
A13.7 FM case ............................................................................................................... 129
A13.8 Wideband Digital ................................................................................................ 132
Annex 14 – Sharing with the radiolocation service (WPR) ..................................................... 134
A14.1 Background ......................................................................................................... 134
A14.2 WPR location and parameters ............................................................................ 135
A14.3 In-band separation distances ............................................................................... 136
A14.4 Separation distances ............................................................................................ 137
A14.5 Conclusions ......................................................................................................... 139
Annex 15 – Spectrum needs evaluation based on spectrum monitoring ................................. 140
A15.1 Spectrum needs evaluation ................................................................................. 140
A15.2 Current amateur station activity and spectrum needs for the average use case .. 141
A15.3 Future spectrum needs for the average use case in a country with average
amateur license density ....................................................................................... 142
A15.4 Current amateur station activity and spectrum needs during a SSB contest in
a country with average amateur license density ................................................. 144
A15.5 Future amateur spectrum needs for the case where additional spectrum is
required in a country with average amateur license density ............................... 145
A15.6 Future amateur spectrum needs in a country with high amateur license density
............................................................................................................................ 146
A15.7 Spectrum needs summary ................................................................................... 146
Attachment 1 to Annex 15 – Spectrum Monitoring and Spectrum Occupancy Results ......... 147
Summary
This Report responds to the invitations of Resolution 658 (WRC-15) to conduct studies to provide information
for the deliberations of WRC-19 on agenda item 1.1 which is for a possible new allocation to the amateur
service in the 50-54 MHz frequency band. The Report provides information on three major topics; spectrum
needs of the amateur service, sharing scenarios between the amateur and incumbent services and possible
status of any allocated spectrum.
Rep. ITU-R M.2478-0 7
The Report is applicable to typical contemporary analog and digital amateur applications, contemporary TV
broadcasting, land mobile and wind profiler systems which are operating in the 50-54 MHz frequency band.
Related Recommendations, Reports and Standards
Recommendation ITU-R SM.329 – Unwanted emissions in the spurious domain
Recommendation ITU-R P.372 – Radio noise
Recommendation ITU-R SM.851 – Sharing between the broadcasting service and the fixed and/or
mobile services in the VHF and UHF bands
Recommendation ITU-R SM.1055 – The use of Spread Spectrum Techniques
Recommendation ITU-R M.1226 – Technical and operational characteristics of Wind Profiler Radars
in the bands in the vicinity of 50 MHz
Recommendation ITU-R BT.1368 – Planning criteria, including protection ratios, for digital
terrestrial television services in the VHF/UHF bands
Recommendation ITU-R M.1634 – Interference protection of terrestrial mobile service systems using
Monte Carlo simulation with application to frequency sharing
Recommendation ITU-R M.1825 – Guidance on technical parameters and methodologies for sharing
studies related to systems in the land mobile service
Recommendation ITU-R P.2001 – A general purpose wide-range terrestrial propagation model in the
frequency range 30 MHz to 50 GHz
Recommendation ITU-R BT.2033 – Planning criteria, including protection ratios, for second
generation of digital terrestrial television broadcasting systems in the VHF/UHF bands
Report ITU-R M.2013 – Wind profiler radars
Report ITU-R SM.2028-1 – Monte Carlo simulation methodology for the use in sharing and
compatibility studies between different radio services or systems
Report ITU-R BT.2387-0 – Spectrum/frequency requirements for bands allocated to broadcasting on
a primary basis
Final Acts of the European Broadcasting Conference (Stockholm, 1961 as revised in Geneva, 2006)
(“ST61”) in the European Broadcasting Area.
Final Acts of the African Broadcasting Conference (Geneva, 1989 as revised in Geneva, 2006)
(“GE89”) in the African Broadcasting Area and neighbouring countries.
Resolution 217 (WRC-97) – Implementation of wind profiler radars.
ETSI Standard EN301783 – Commercially available amateur radio equipment; Harmonised Standard
covering the essential requirements of article 3.2 of the Directive 2014/53/EU
1 Introduction
1.1 Background to this Report
This Report responds to the invitations of Resolution 658 (WRC-15) to conduct the following studies
in order to support the deliberations of WRC-19 on agenda item 1.1:
1) to study spectrum needs in Region 1 for the amateur service in the frequency band
50-54 MHz;
8 Rep. ITU-R M.2478-0
2) taking into account the results of the above studies, to study sharing between the amateur
service and the mobile, fixed, radiolocation and broadcasting services, in order to ensure
protection of these services.
The frequency band 50-54 MHz is allocated on a primary basis to the Amateur Service in Regions 2
and 3 and the intent of Resolution 658 (WRC-15) is to study a possible global frequency
harmonization.
1.2 Structure of this Report
This Report is divided into two parts: the body of the Report, from sections 1 to 10 provides a
summary of the studies and results; and the Annexes (1 through 15) provide complete technical details
of the studies. The Annexes are attached more-or-less as they were submitted in the various input
contributions that were made to Working Party meetings; the only changes were editorial to make the
style consistent throughout the Report.
1.3 Geographic considerations
The geographic focus of this Report is almost entirely European due to the fact that most contributions
were received from European countries.
2 Current usage of the 50-54 MHz frequency band in Region 1
2.1 The amateur service
In Region 1, African countries listed in No. 5.169 of the Radio Regulations (RR) have an allocation to
the amateur service in the 50-54 MHz frequency band on a primary basis.
A number of other Region 1 countries have authorized the use of all or parts of the 50-52 MHz
frequency band by the amateur service on a mainly national secondary (but sometimes national primary)
basis in accordance with RR No. 4.4.
CEPT’s European Table of Frequency Allocations allocates the 50-52 MHz frequency band to the
amateur service on a secondary basis. Thus 75% of CEPT’s membership authorize amateur usage
within the 50-52 MHz frequency band mainly on a secondary basis. The permitted maximum power
of such stations is mostly 100 W, in some countries there are territorial limitations with regard to
power and frequencies.
Table 1 provides a list of Region 1 Administrations and the conditions for using the 50-54 MHz
frequency band.
TABLE 1
Conditions for amateur service usage of the 50-54 MHz band in Region 1, as at May 2019
Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2
AFS 50-54 P 5.169 DNK 50-52 S
LBR
No Info
S 50-52 S
ALB 50-52 S
E 50-52 S
LBY
No
Info
SDN
No
Info
ALG NO
EGY NO
LIE
50-52 S
SEN 50-51 P
5.16
9
AND 50-52 S
ERI
No Info
LSO
50-54 P
5.16
9 SEY
No Info
AGL
No Info
EST 50-52 S
LTU
50-52 S
SMR 50-52 S
ARM NO
ETH
No Info
LUX 50-52 S
SOM 50-54
Rep. ITU-R M.2478-0 9
TABLE 1 (end)
Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2
ARS NO
F 50-52 S
LVA 50-52 S
SRB 50-51.9 S
AUT 50-52 S
FIN 50-52 S
MAU NO
SRL
No Info
AZE NO
G
50-51 P
MCO 50-52 S
SSD
No Info
BEL 50-52 S
51-52 S
MDA NO
STP
No Info
BEN
No Info
GAB
No Info
MDG
No Info
SUI 50-52 S
BFA
No Info
GEO NO
MKD 50-52 S
SVK 50-52 S
BHR
50-50.5 P
GHA
No Info
MLI
No Info
SVN 50-52 S
50.5-52 S
GMB
No Info
MLT 50-52 S
SWZ 50-54 P 5.169
BIH 50-52 S
GNE
No Info
MNE 50-52 S
SYR
No Info
BLR NO
GNB
No Info
MNG
No Info
TZA
No Info
BOT 50-54 P 5.169 GRC 50-52 S
MOZ
No Info
TCD
No Info
GUI No info
BUL 50.05-50.2 S
HNG 50-52 S
MRC
No Info
TGO
No Info
BDI
No Info
HOL 50-52 S
MTN
No Info
TJK NO
CAF
No Info
HRV 50-51.9 S
MWI 50-54 P 5.169 TKM NO
CME
No Info
I 50-52 S
NGR
No Info
TUN NO
COD 50-54 P 5.169 IRL 50-52 S
NIG NO
TUR NO
COG
No Info
IRQ
No Info
NMB 50-54 P 5.169 UAE
No Info
COM
No Info
ISL 50-52 S
NOR 50-52 P
UGA
No Info
CPV
No Info
ISR 50-52 S
OMA 50-52 S
UKR 50.08-50.28 S
CTI
No Info
JOR 50-51.5 S
POL 50-52 S
UZB NO
CVA 50-52 S
KAZ NO
POR 50-52 S
YEM
No Info
CYP 50-51 S
KEN NO
QAT
No Info
ZMB 50-54 P 5.169
CZE 50-52 S
KGZ NO
ROU 50-52 S
ZWE 50-54 P 5.169
D 50.03-51 S
KWT
No Info
RUS NO
DJI
No Info
LBN 50-51.975
RRW 50-54 P 5.169
5.169 Alternative allocation: in Botswana, Lesotho, Malawi, Namibia, the Dem. Rep. of the Congo, Rwanda, South Africa, Swaziland, Zambia and Zimbabwe, the band 50-54 MHz is allocated to the amateur service on a primary basis. In Senegal, the band 50-51 MHz is allocated to the amateur
service on a primary basis. (WRC-12)
1 Status: P = primary, S = Secondary, No info = no information available.
2 RR is the applicable Radio Regulation Article 5 footnote.
According to IARU Region 1 frequency planning, in countries where allowed, the frequency range
50.0-50.5 MHz is utilized for weak signal communications, which would derive great benefit from
harmonization with Regions 2 and 3.
The frequency range 50.5-52 MHz is currently utilized for voice communications using frequency or
phase modulation, digital communications, Gateways and FM Repeaters.
2.2 The radiolocation service
RR No. 5.162A provides for an additional allocation to the radiolocation service on a secondary basis
in a number of countries in Region 1, limited to the operation of wind profiler radars in accordance
with Resolution 217 (WRC-97). Very few wind profiler radars currently operate in the 50-54 MHz
frequency band.
2.3 The broadcasting service
The 47-68 MHz frequency band is allocated to the broadcasting service on a primary basis in Region
1. In recent years, in the majority of Region 1 countries broadcasting has significantly declined in the
47-68 MHz frequency band and analogue television is expected to be phased out by 2020 as
10 Rep. ITU-R M.2478-0
conversion to digital television broadcasting in a different part of the spectrum proceeds. However in
parts of Eastern Europe the band is still used for analogue television.
As of March 2019 the number of television stations included in the MIFR within the frequency band
48-56 MHz (1st TV channel) in some Region 1 countries is provided in Table 2.
TABLE 2
ITU code Number of
records
ARM 19
AZE 22
BLR 2
GEO 2
KAZ 8
KGZ 10
MDA 5
RUS 344
TJK 18
TKM 2
UKR 18
UZB 22
A number of other countries in Region 1 still have records in the MIFR and in regional Plans in this
frequency band.
Some administrations have already indicated analogue switch-off in the upper VHF and UHF bands,
but the operational status of the lower Band I VHF relevant assignments is not known.
However, the total number of operational high and medium-power television transmitters within the
48-56 MHz frequency band in the Russian Federation is about 500 (344 in the MIFR as of 28th of
March 2019) and it is expected that a large number of these will remain operational for the foreseeable
future. The frequency band 48-56 MHz is also being considered by some administrations for the
deployment of digital television and multimedia broadcasting systems. There are also proposals to
expand the use of the DVB-T2 system in frequency bands below 174 MHz, as well as the introduction
of advanced sound and multimedia broadcasting systems in the lower part of broadcasting band 1,
including frequencies from 50-54 MHz.
2.4 The fixed and mobile services
Footnote RR No. 5.164 allocates part, or all, of the frequency band 47-68 MHz to the land mobile
service on a primary basis in a number of countries in Region 1, and footnote RR No. 5.165 allocates
this frequency band to the fixed service and the mobile (except aeronautical mobile) service in a
number of African countries. It has to be noted that RR No. 5.167 and RR No 5.167A provide
allocations to the fixed service on a primary basis in the 50-54 MHz frequency band to countries in
Region 3 which border Region 1.
An examination of the ITU Master International Frequency Register (MIFR) indicates a number of
notifications for fixed services in the 50-54 MHz frequency band with none in administrations
bordering Region 1. The MIFR also indicates that there are four notifications in one Region 1
administration which date back many years.
Rep. ITU-R M.2478-0 11
There may also be fixed usage in Region 1 which has not been notified to the MIFR which may
include short range fixed use on a national basis.
2.5 Inter-regional sharing between services
Due to the different service allocations as given in various footnotes in the Radio Regulations there
is inter-regional sharing between services at the borders between Region 1 and Regions 2 and 3.
2.6 Others applications in the 50-54 MHz frequency band
For information, the radioastronomy service has no allocations in the 50-54 MHz band. However
some radio astronomy instruments are operating on a non-protection basis in the band 50-54 MHz in
Region 1. This application is not covered by Resolution 658 (WRC-15) and no studies have been
carried out for its protection.
3 Spectrum needs for the amateur service in Region 1
This section of the Report together with Annexes 1, 3, 4 and 15 addresses the spectrum needs for an
allocation in the frequency band 50-54 MHz to the amateur service in accordance with Resolution 658
(WRC-15). In particular current and future spectrum applications, usage and needs are discussed and
an application-based method for determining spectrum needs in the amateur service has been
developed.
3.1 General considerations
Activities in the frequency band 50-54 MHz feature many of the key aspects of the amateur service
e.g. two-way communication, technical investigation and self-training. Furthermore, propagation
characteristics in this part of the spectrum are highly attractive for amateur investigations since
50-54 MHz lies in the transition zone between HF with its sky wave propagation and VHF with its
more line of sight propagation modes.
A 50-54 MHz frequency allocation in Region 1 will allow for harmonised spectrum in all three ITU
Regions and will enable the International Amateur Radio Union (IARU) to develop harmonised band
utilisation plans.
More than that, access to the 50-54 MHz frequency band in Region 1 would ease problems
experienced by the amateur service caused by the widespread rise in environmental noise in the MF
and HF spectrum which increasingly renders frequencies less than 30 MHz allocated to the amateur
service subject to disturbance and harmful interference, particularly in urban environments.
It would also alleviate the lack of VHF spectrum allocated to the amateur service in Region 1, since
there are only 2 MHz of VHF spectrum in one sub-band allocated to the amateur service, whereas
Region 2 currently has 13 MHz of spectrum in three sub-bands available to the amateur service for
experimentation.
3.2 Background on current usage on national basis in Region 1
At present, where use is permitted in the 50-52 MHz frequency band in Region 1, the most common
analogue and digital amateur service applications use bandwidths of less than 25 kHz, within which
long distance weak-signal and propagation beacon applications are globally coordinated within
50.0-50.5 MHz. The frequency range 50.5-52 MHz is currently utilised for two-way voice
communications using frequency or phase modulation, data, gateways and FM repeaters. Digital
voice and data is already being used for 50 MHz networks in the amateur service incorporating text
12 Rep. ITU-R M.2478-0
and simple voice messaging. Such systems have shown to be of considerable value in emergency
communications. See RR No. 25.3.
3.3 Other envisaged applications
Based on current experimentation, digital communication applications are to be envisaged, combining
voice, video and data encompassing a wide range of necessary bandwidths not exceeding 500 kHz
for which usage is not currently possible in some countries. Examples of such new application
scenarios will include:
– Reduced Bandwidth Digital Amateur Television (RB-DATV). With leading-edge amateur
innovation, currently the lowest data rate achievable for RB-DATV (MPEG 4/DVB-S
QPSK) is 333 kb/s requiring a necessary bandwidth of 500 kHz.
– IP links/mesh networks and innovative compressed multimedia transmission systems
(currently based on DVB-S2/MPEG technologies adapted for terrestrial use).
– Adaptations of HAMNET mobile terminal devices.
Many of these applications currently exist in the amateur service microwave bands and in a few
Region 1 countries where experimental amateur VHF developments are occurring. Their further
development and adaptation to the frequency band 50-54 MHz requires the certainty of a sufficiently
wide frequency allocation in Region 1.
Access to more VHF spectrum would additionally encourage development of new technologies to
support disaster relief in accordance with the IARU-ITU and IARU-Red Cross/Red Crescent
Memoranda of Understandings on disaster relief operations.
3.4 Designated application categories to be taken into account in spectrum needs estimation
Based on the above elements and on the background of existing usage and anticipated growth in
digital systems, it is necessary to determine spectrum needs based on the following application
categories within the range 50-54 MHz:
TABLE 3
Application categories to be considered when assessing amateur spectrum
needs in the frequency band 50-54 MHz
Designated application categories
Contact range at
usable SNR
(km)
Required
bandwidth per
channel
Narrowband weak-signal communications e.g. CW, SSB and
digital weak signal data modes1 250 500-3 000 Hz
24/7 propagation beacons 500-1 000 Hz
Relatively narrowband (≤ 25 kHz) digital voice, FM voice, data. 70 25 kHz
Repeaters and gateways 100 25 kHz
Wider bandwidth predominantly digital applications (see A1.10
and A1.11) 40/70 500 kHz
1 ‘Weak signal data modes’ are structured for very basic communications with low data rate and narrow
bandwidth for best weak signal performance.
Rep. ITU-R M.2478-0 13
Where “Contact Range at usable SNR” is the distance between the transmitter and receiver at which
the receiver is able to receive a signal at a level which permits demodulation and the correct recovery
of the transmitted message.
3.5 Application based assessment of spectrum needs
An application-based approach suitably adapted to amateur service usage is considered appropriate
for the amateur service to assess spectrum needs in the frequency band 50-54 MHz with a focus on
the specific applications expected in this frequency band. (See Annex 3.)
An example of this approach can be found in Recommendation ITU-R M.1651 – A method for
assessing the required spectrum for broadband nomadic wireless access systems including radio local
area networks using the 5 GHz band, which provides a similar methodology for assessing spectrum
requirements for RLANs. This Recommendation has since been further developed and is one of the
methods used for other WRC agenda items.
The method can:
– take account of the expected capabilities and usage scenarios, and
– be readily implemented using common software tools such as a spreadsheet.
Details of the spectrum needs calculation process using this approach are provided together with a
spreadsheet containing typical values. The results derived from using this approach are strongly
dependent upon the input parameters used.
Results from two different studies are provided in this Report. Both studies are based on the same
application based approach, but using different parameters for the number of active amateur stations
and session durations.
The first study presented in § 3.6 applies parameter values derived from spectrum monitoring
measurement results together with a contest log data analyses. In addition, for average as well as for
high density amateur population areas, two spectrum use situations are considered: an average, every
day spectrum use situation and an exceptionally intensive spectrum use occurring e.g. during contests
or situations of exceptional propagation conditions.
A second study, presented in § 3.7, was developed based on long term amateur usage experience of
the different applications highlighted in Table 4, along with the amateur population density. This
study calculates the spectrum required for average and high-density amateur population cases, which
are representative of the situation in a number of European countries.
Both studies considered the applications highlighted in Table 4.
TABLE 4
Assumed application usage distribution used for the studies
SSB FM Wideband
modes Repeaters Infrastructure
App 1 App 2 App 3 App 4 App 5
60% 5% 5% 20% 10%
3.6 Study 1 based on spectrum occupancy and contest log data analysis
Section 3.6 is based on the work presented in Annex 15.
14 Rep. ITU-R M.2478-0
3.6.1 Spectrum needs evaluation methodology and parameters
The application based methodology to estimate the spectrum needs for amateur radio service in the
frequency band 50-54 MHz can be found in Annex 3.
The spectrum need is calculated for average and high population density areas, taking into account
everyday usage situations as well as exceptional usage situations where additional spectrum is
required. Accordingly the spectrum needs are calculated for the following cases:
– Case A: Average, everyday use case which occurs with a probability of 98% in time.
– Case B: Where additional spectrum is required. This situation occurs e.g. during contests,
exceptional propagation conditions, public service and special events. It is assumed, that
those cases do not occur during more than seven days a year. This corresponds to situations
which occur with a probability of less than 2% in time.
Both usage situations are considered in calculations for European countries with a typical as well as
with maximum amateur station density.
The spectrum needs evaluation based on the application based approach considers different
parameters which need to be defined or derived. The derivation of the parameters for active amateur
stations density and session duration is not straightforward but are of central importance. For this
study, they are obtained through an analysis of IARU 2017 50 MHz contest log data together with
the analysis of spectrum monitoring data as well as application of correction factors regarding the
forecasted growth of the amateur radio community and propagation conditions. To obtain figures for
future spectrum use and future conditions, the following data and procedures are used:
– The number of active amateur stations for the Case A situation in a typical European country
is evaluated based on spectrum monitoring results obtained through a measurement campaign
which has taken place in the period of April to July 2018. It turns out, that for Case A the
spectrum occupancy is well below 1%.
– The session duration for an active amateur station in a Case A scenario is assumed to be
2 hours/day on average when about 3% of the existing amateur licenses are daily accessing
the band 50-52 MHz.
– The session duration for Case B is calculated based on the maximum duration of a two way
contact during the IARU 2017 50 MHz contest. Therefore the evaluated figure for the session
duration during contests may represent an overestimation.
– The number of active amateur station for the case B is evaluated based through an analysis
of IARU 2017 50 MHz contest log data. The spectrum monitoring results of the IARU 2018
50 MHz contest showed a lower activity than the activity of the IARU 2017 50 MHz contest
(evaluated based on contest log data). This may be caused by significantly worse propagation
conditions during the 2018 contest compared to the 2017 contest. Therefore, the monitoring
data of the IARU 2018 50 MHz contest are disregarded for the spectrum needs analysis.
When assuming a session duration as described above, it was found that the evaluated number
of active amateur stations was 68% of the existing amateur licenses.
– For the evaluation of the future need, the growth of the number for amateur licenses is linearly
extrapolated to the year 2038.
– It is shown that the current spectrum use in the frequency band 50-52 MHz for the average,
everyday use case is very low, while during contests a strong increase of the use can be
observed, but only for narrow band modes. However, the use of the spectrum in the 50.5-
52 MHz frequency band by all other modes like FM, RTTY, digital communication, etc. is
always very low. Accordingly, for the determination of future requirements, the ratios of the
case B are considered for narrowband applications, while for FM, repeaters, Infrastructure
and Wideband modes the circumstances of daily use (case A) are considered.
Rep. ITU-R M.2478-0 15
– It is shown, that the number of active amateur stations during the IARU 2017 50 MHz contest
was significantly higher, than during the ‘big opening’ on the 28.05.2018. Therefore no data
from this ‘big opening’ but only from the IARU 2017 50 MHz contest is considered for Case
B spectrum needs evaluation.
– Because future maximum solar activity may stimulate a more intense use of the Band 50-
52 MHz, the calculation for future spectrum needs considers in average 50% additional
amateur activity due to high solar activity.
– Figures for high amateur station populations are obtained based on data for average amateur
population density corrected through linear interpolation.
3.6.2 Spectrum needs summary
The spectrum need is calculated for average and high population density areas, taking into account
everyday usage situations as well as exceptional usage situations where additional spectrum is
required. Accordingly the spectrum needs are calculated for two different cases:
– Case A: Average, everyday use case which occurs with a probability of 98% in time.
– Case B: Where additional spectrum is required. This situation occurs e.g. during contests,
exceptional propagation conditions, public service and special events. It is assumed, that
those cases do not occur during more than 7 days a year. This corresponds to situations which
occur with a probability of less than 2% in time.
Both usage situations are considered in calculations for European countries with a typical as well as
with maximum amateur station density.
It is shown, that the current spectrum use in the frequency band 50-52 MHz for the average, everyday
use case is very low, while during contests a strong increase of the use can be observed only for
narrow band modes. The use of the spectrum in the 50.5-52 MHz frequency band by all other modes
like FM, RTTY, digital communication, etc. is always very low, independent of usage situations like
contests or propagation conditions. Accordingly, for the determination of future requirements, the
ratios of the case B are considered for narrowband applications, while for FM, repeaters,
Infrastructure and Wideband modes only the circumstances of the everyday use case (case A) applies.
Current and future spectrum needs of the Amateur Service in the 50 MHz frequency band are shown
in Table 5. The index “av” and “high” for the calculated bandwidth numbers in the Table 5 stand for
countries with average respectively high amateur station density. Values in brackets represent real
calculated, respectively measured values, while all other numbers are rounded up to integer multiples
of the respective channel bandwidth.
16 Rep. ITU-R M.2478-0
TABLE 5
Current and future spectrum needs
Spectrum usage
situation Applications
Frequency
range
(MHz)
Current average
occupied bandwidth
in a typical
European country
measured during a
four-month period
in spring 2018
Future spectrum
needs (MHz)
according to
Study 1
Total
maximum All applications 0.226 MHzav
1.365 MHzav
1.702 MHzhigh
Case A
During average
days
(98% of time)
Existing
applications
Narrow band and
Telegraphy 50.0-50.5
0.003 MHz
(0.0561 kHz
+ 2.52 kHz)
0.009 MHzav
0.021 MHzhigh
FM, Repeaters,
Digital, etc. 50.5-52.0
0.025 MHz
(1.69 kHz)
0.125 MHzav
0.225 MHzhigh
New
applications
Wide Band,
Infrastructure > 50.5 n.a.
1.0 MHzav
1.0 MHzhigh
Case B
During contests
and exceptional
conditions
(during 2% of
time)
Existing
applications
Narrow band and
Telegraphy 50.0-50.5 0.219 MHz
0.240 MHzav
0.477 MHzhigh
FM, Repeaters,
Digital, etc. 50.5-52.0
0.025 MHz
(0.033 kHz)
0.125 MHzav
0.225 MHzhigh
New
applications
Wide band,
infrastructure > 50.5 n.a.
1.0 MHzav
1.0 MHzhigh
3.7 Study based on estimations and long term experience
Section 3.7 is based on the work presented in Annex 1.
3.7.1 Introduction
An application based approach as described in § 3.5 above was used. This has been found to be
suitable for estimating the spectrum needs for current and envisaged amateur applications in the
50-54 MHz frequency band. A nominal set of frequency ranges has been used to align with the
existing and expected categories of applications.
The results from this calculation procedure need to be considered carefully given that the output might
be sensitive to the input parameter values on the usage of advanced applications which can be drawn
from a large range of possible values. This input parameter, on the other hand, could reflect the
different situation in particular regions or countries.
3.7.2 Spectrum needs evaluation methodology and parameters
This paragraph describes the various parameters used to calculate the spectrum needs when using the
above described application based methodology to estimate the spectrum needs for the amateur radio
service in the frequency band 50-54 MHz.
The characteristics of amateur service stations used in spectrum needs calculations are contained in
Table 9 of this Report.
In addition to the number of amateurs in Europe, it is estimated that 8% of these will use the
50-54 MHz band.
Rep. ITU-R M.2478-0 17
The duration of a spectrum access is assumed to be 2 hours/day except for the repeaters and
infrastructure applications which are assumed to operate 24 hours/day with a duty cycle of 50%.
The split between the various applications is taken from Table 4. In addition the contact range at
usable SNR for infrastructure is set from operational experience to 70 km.
A circular ‘cell’ is also defined based on the contact range at usable SNR for each application
according to Table 4.
Bandwidth for each application is taken from Table 3 with the addition of propagation beacons with
a spectrum usage of 100 kHz.
To accommodate a mix of analogue and digital applications all calculations are based on a simple
channel bandwidth. However many transmission modes are not compatible with each other and
cannot share spectrum, therefore a summation of spectrum is required for each individual application.
Additionally, the calculated spectrum for each application is rounded up to the next integer multiple
of the application channel bandwidth as a fractional bandwidth would not allow the application to
function correctly.
3.7.3 Calculation steps
This section shows how the spectrum needs are calculated.
1 Calculate the average number of amateurs or transmitters per km2 at any time in the year
using spectrum in the 50-54 MHz frequency band for a specific application.
2 Calculate the number of amateurs within one ‘cell’ using a specific application within 50-
54 MHz band. (A ‘cell’ is a circle with a radius of the “Contact range at usable SNR”.)
3 Calculate the required spectrum within a ‘cell’ for a specific application.
4 Calculate the average bandwidth for the specific application over the operating session time.
5 Sum up the aggregate spectrum required within the band 50-54 MHz.
An embedded Spread Sheet that reflects these calculations has been provided in Annex 3.
3.7.4 Results of study
Two sets of calculations have been performed and documented in the embedded Spread Sheet in
Annex 3. In addition to the two cases studied in § 3.6 (A and B) two cases (C and D) dealing with
two amateur population densities are considered in this section.
– Case C: The spectrum requirements of the amateur service in the frequency band 50-54 MHz,
has been calculated from the number of radio amateurs in Europe as found in Annex 2 divided
by the area of Europe based an average amateur population density for 100% of time. This
gives 0.073 amateur stations per km2 for the case of average amateur population. The
spectrum requirement for each application in this case is shown in Table 6 column A and
shows that a total of 4.162 MHz of spectrum is currently required to meet the average
European spectrum requirements of the amateur service in the frequency band 50-54 MHz.
– Case D: The spectrum requirements of the amateur service in the frequency band 50-54 MHz,
has also been calculated with a higher number of amateurs per km2 to reflect the situation in
areas with a high amateur population density e.g. in the case of Germany. This gives 0.209
amateur stations per km2 for the case of areas with a high amateur population. The spectrum
requirement for each application in this case is shown in Table 6 column B and shows that a
total of 10.024 MHz would be required to meet the spectrum needs in such an area with a
higher density of radio amateurs.
18 Rep. ITU-R M.2478-0
TABLE 6
Required spectrum for average and high-density amateur population
Applications
Required Spectrum (MHz)
C
Average amateur population
Required Spectrum (MHz)
D
High amateur population
SSB 0.087 0.249
FM 0.025 0.025
Wideband modes 0.500 0.500
Repeaters (FM) 0.950 2.650
Infrastructure 2.500 6.500
Propagation beacons 0.100 0.100
Total amount of spectrum 4.162 MHz 10.024 MHz
The detailed evaluation of the spectrum needs figures can be found in the Annex 3.
3.8 Reasons for differences between the studies
For both studies the same application based approach, the same technical and operational parameters
for the different amateur applications.
It should further be noted:
– Analysis of contest reception logs makes the assumption that all band activity is reported, while
cross checking of reports provides some confidence there is still the possibility that band usage
is under reported. This is compensated by a margin in Study 1.
– Although some of the applications are based on current experience in other frequency bands,
there remain uncertainties concerning future developments and this may affect the spectrum
needs calculations.
Therefore the calculations need to be interpreted carefully.
The main different assumptions in the respective studies are:
– Study 1 calculates the needs based on the population density of active amateur licensees
(percentage of amateurs using this application e.g. SSB, FM, etc.), which is calculated to be
a maximum of 68% of the density of 50 MHz stations during a contest and less than 5% for
everyday use. Study 2 calculates with the total (100%) of 50 MHz stations. This explains the
similarity of spectrum needs calculation results between Study 1 for SSB contest case and
Study 2 for SSB.
– Contest like situations for Repeaters, Infrastructure and WB modes are excluded in Study 1.
Based on today’s knowledge the spectrum needs for the latter mentioned application does
not increase during contest or during occurrence of exceptional propagation conditions.
Accordingly, Study 1 calculates for those applications with less than 5% active stations while
Study 2 calculates with all (100%) of 50 MHz stations. This explains the main difference in
the results of both studies.
– Study 1 uses a session duration for contest situation of 4.65h/24h while Study 2 uses 2h/24h
for average use, thus Study 1 is based on higher activity.
Rep. ITU-R M.2478-0 19
3.9 Summary of spectrum needs from the studies
The results of Study 1 and Study 2 regarding current and future spectrum needs of the Amateur
Service in the 50 MHz frequency band are summarized in Tables 7 and 8. The index ‘av’ and ‘high’
for the numbers in the Table 7 stand for countries with average or high amateur station density. All
numbers are rounded up to integer multiples of the respective channel bandwidth
TABLE 7
Current and future spectrum needs of existing and new Amateur service applications
Spectrum
usage
situation
Applications
Frequency
range
(MHz)
Current
occupied
bandwidth(1)
Future
spectrum needs
(MHz)
according
Study 1
Future
spectrum needs
(MHz)
according
Study 2
During
average
days
(98% of
time)
Existing
applications
Narrow band (SSB
& telegraphy)
Beacons 50.0-50.5 0.003 MHzav
0.009 MHzav
0.021 MHzhigh
0.087 MHzav
0.25 MHzhigh
0.1 MHz
FM, repeaters, NB
digital, etc. 50.5-52.0 0.025 MHzav
0.125 MHzav
0.225 MHzhigh
0.975 MHzav
2.7 MHzhigh
New
applications
Wide band,
infrastructure > 50.5 n.a.
1.0 MHzav
1.0 MHzhigh
3.0 MHzav
7.0 MHzhigh
During
contests
and
exceptional
conditions
(during 2%
of time)
Existing
applications
Narrow band (SSB)
& telegraphy 50.0-50.5 0.219 MHzav
0.24 MHzav
0.477 MHzhigh n.a.
FM, repeaters,
digital, etc. 50.5-52.0 0.025 MHzav
0.125 MHzav
0.225 MHzhigh n.a.
New
applications
Wide band,
infrastructure > 50.5 n.a.
1.0 MHzav
1.0 MHzhigh n.a.
(1) In a typical European country measured during a four-month period (April – July) in spring 2018.
As it is shown in the Table 7 depending on the conducted studies, the spectrum needs for amateur
service in the band 50-54 MHz for the average usage days scenario and average amateur station
density are estimated as:
– for Narrow band SSB and Telegraphy applications: 0.009/0.087 MHz;
– for Beacons: 0.1 MHz;
– for FM, Repeaters, NB Digital applications: 0.125/ 0.975 MHz;
– for Wide Band, Infrastructure applications (new applications): 1/3 MHz;
– for all applications: 1.234 / 4.162 MHz.
For the average usage days scenario and high amateur station density the spectrum needs are:
– for Narrow band SSB and Telegraphy applications: 0.009/0.087 MHz;
– for Beacons: 0.1 MHz;
– for FM, Repeaters, NB Digital applications: 0.125/ 0.975 MHz;
– for Wide Band, Infrastructure applications (new applications): 1/3 MHz;
– for all applications: 1.234 / 4.162 MHz.
For the contests and exceptional conditions scenario and average / high amateur station density the
spectrum needs are estimated as:
20 Rep. ITU-R M.2478-0
– for Narrow band SSB, Telegraphy, Beacons applications: 0.24 / 0.477 MHz;
– for FM, Repeaters, NB Digital applications: 0.125 / 0.225 MHz;
– for Wide Band, Infrastructure applications (new applications): 1 MHz;
– for all applications: 1.365 / 1.702 MHz.
In the studies the average amateur station density corresponds a population density of amateur
operators equal 0.073 licensees/km2, the high amateur station density corresponds – 0.2092
licensees/km2.
There are no particular studies for the low amateur station density scenario, e.g. for a population
density of amateur operators less than 0.007 licensees/km2. But from studies results for the average
usage days scenario it could be observed that there is approximately a linear relationship between
density of amateur operators and spectrum needs (1.234 MHz for 0.073 licensees/ km2 and
4.162 MHz for 0.2092 licensees/km2). So for the density of amateur operators less than 0.007
licensees/km2 (it is 10 times less than 0.073 licensees/km2), for all applications spectrum demand
could be assessed as 0.1234 / 0.4162 MHz for the average usage days scenario. Taking into account
the minimum bandwidths required by existing and new amateur applications, it could be assumed
that for the average all usage day scenarios the maximum spectrum needs for existing applications
will be less than 200 kHz.
In Table 8 maximum needs for amateur service in the band 50-54 MHz is presented according to the
provided studies.
TABLE 8
Current and future total spectrum needs of existing and new Amateur service applications
Applications Current occupied
bandwidth(1)
Future spectrum needs
(MHz) according
Study 1
Future spectrum needs
(MHz) according
Study 2
Maximum need
considering all
applications
0.244 MHzav 1.365 MHzav
1.702 MHzhigh
Beacons not included
4.162 MHzav
10.024 MHzhigh
(1) In a typical European country measured during a 4 month period (April – July) in spring 2018.
3.10 Status of possible allocation
One view is that sharing studies (see § 5, 7 and 8) have demonstrated that large separation distances
are required to allow coexistence with incumbent services. Given those results, introducing a new
service in the band needs to be done with appropriate status that will allow to avoid placing any
additional constraint on the secondary services in place but also to ensure coexistence with the
primary incumbent services in place. Thus, a primary allocation to the amateur service in this band
should not be considered, only a secondary allocation on the whole envisaged spectrum would allow
maintaining equilibrium in the band.
An alternative view was expressed that that the amateur service seeks primary status within the
50-54 MHz frequency band, in common with Regions 2 and 3 as per ITU Recommendation 34.
In addition a secondary allocation in the band would not satisfy the concerns of the amateur service
e.g. that due account would be taken of a secondary allocation to the amateur service in Region 1 in
any future frequency allocation activity. Experience has shown that when studying a new allocation
with regards to sharing with the amateur service as secondary incumbent service, does not achieve
support when ITU plans WRCs agenda items, even if the need to address incumbent services is
Rep. ITU-R M.2478-0 21
specified. For example, see Resolution 239 (WRC-15) invites ITU-R b) in respect of the band 5 725-
5 850 MHz where the secondary amateur service was not included.
4 Characteristics of amateur stations for sharing studies
4.1 Global characteristics
There is an existing allocation to the amateur service between 50-54 MHz in ITU Regions 2 and 3;
therefore the most recent version of Recommendation ITU-R M.1732 – Characteristics of systems
operating in the amateur and amateur-satellite services for use in sharing studies, contains the range
of current characteristics that might be used by the amateur service across the world.
4.2 Specific Region 1 characteristics
Considering contemporary and future likely use of the 50-54 MHz frequency band by the amateur
service in Region 1, a subset of characteristics is suggested for use in the sharing analyses that are
contained in this Report. Typical transmission modes that may be used in this band are Morse
telegraphy, analogue and digital voice, narrow band data modes and reduced bandwidth digital
television; Tables 3 and 9 provides the necessary parameters used in the studies that follow.
These parameters are based on the following considerations:
– The suggested modes specified in § 3.3 are subject to future development; however the
maximum bandwidth and power given in the Table are likely to be maximum values
irrespective of future transmission modes.
– The height of amateur station antennas are generally limited by local housing planning
considerations and economic factors, moreover, amateur stations may be used ‘in the field’
for special events, contests etc. so a probability distribution is appropriate to cover these
situations.
– The percentage of time a station transmits cannot be precisely known, however even a very
active amateur operator is unlikely to transmit for more than approximately one hour per day
(on average), so a 5% duty cycle is assumed.
TABLE 9
Suggested parameters of the amateur service for use in the sharing studies of this Report
Parameter Value
Frequency range 50.0-54.0 MHz
Emission mode SSB (J3E)
CW (A1A)
FM (F3E) Wideband Digital
OFDM, QPSK, QAM
Power and duty cycle 20 dBW @ 2.5%
10 dBW @ 5%
13 dBW @ 5% 17 dBW @ 5% or
4 dBW in 16 kHz
Emission masks:
Out of band domain
Spurious domain
ITU-R SM.1541-6 Annex 9
ITU-R SM.329-12
Necessary emission
bandwidth
3 kHz
300 Hz
16 kHz 300 kHz
22 Rep. ITU-R M.2478-0
TABLE 9 (end)
Parameter Value
Forward antenna gain 9.4 dBi
(Directional)
2.5 dBi
(Omni-Directional)
2.5 dBi
(Omni-Directional)
4 dBi
(Directional)
Polarisation Horizontal Vertical Vertical
Antenna type Yagi Monopole Monopole or low gain
directional antenna
Antenna heights for use in
simulations and probability of
use
10 m @ 95%
20 m @ 2.5%
100 m @ 1.8%
1 000 m @ 0.7%
10 m @ 95%
20 m @ 5%
10 m @ 95%
20 m @ 5%
4.3 Antenna type and polarization
The suggested antenna types are representative of typical contemporary amateur practice. Usual
practice of the amateur service is to use horizontally polarized Yagi antennas in the 50-50.5 MHz
frequency range and vertically polarized monopole antennas above 50.5 MHz for FM and other
relatively short range transmission modes. However individual amateur operators are free to use
whatever polarization is appropriate for the best link performance, consequently the only mention is
to note that cross-polarization may potentially reduce the probability of interference by some amount
in some cases.
4.4 Propagation Factors
This Report only considers radio propagation characteristics that are found in the various propagation
models: Extended-Hata, Recommendations ITU-R P.1546, ITU-R P.2001, ITU-R P.526, etc. (see
Table 10). Factors such as troposcatter and anomalous propagation conditions play an important role
in radio propagation for the considered frequency range when time percentage of less than 50% and
long distance ranges are considered. Those propagation factors are taken into account in the
interference studies in the section “sharing with the mobile service” in which the propagation model
ITU-R P.2001 is applied. This propagation model is recommended by ITU-R Working Party 3L to
be used for these studies.
TABLE 10
Propagation Models – ITU Radiocommunication Services sharing
with Amateur Service
Land mobile Broadcasting Radiolocation
SEAMCAT –
EHATA
X X
SEAMCAT-1546 X
E-HATA X X
ITU-R P.1546 X
ITU-R P.2001 X X
ITU-R P.526 X
Rep. ITU-R M.2478-0 23
Towards the conclusion of work on this Report ITU-R Working Party 3L expressed concern about
the applicability of the Extended-Hata (E-Hata) propagation model that has been used in some studies,
because the lower frequency limit of the Extended-Hata model is 150 MHz and because this model
does not take into account the effects of troposcatter.
The CEPT document ECC Report 252 published in April 2016 indicates that the E-Hata model as
implemented in the Spectrum Engineering Advanced Monte Carlo Analysis Tool (SEAMCAT) is
applicable over the frequency range 30 MHz – 3 GHz and recommended for distance ranges of up to
40 km for services working in non-LOS/cluttered environment. On that basis the model was used to
simulate a number of interference scenarios as part of assessing the possibility of the amateur service
sharing with the broadcasting, mobile and radiolocation services in some situations.
5 Sharing with the mobile service
According to RR Article 5.164 and the European Table of Frequency Allocations (ECA TABLE), the
frequency band 47-68 MHz is allocated to the land mobile service on a primary basis.
Four approaches have been studied:
– A Monte-Carlo simulation of sharing with mobile service, performed with the CEPT
SEAMCAT simulation software and using the Extended-HATA propagation model
(Annex 10);
– A Minimum-Coupling Loss sharing study between amateur radio stations and governmental
mobile systems, using the P.2001-2 propagation model (Annex 11),
– A coverage mapping study between amateur radio stations and governmental mobile
systems, using the P.2001-2 propagation model (Annex 12)
– A Monte-Carlo simulation of amateur service versus mobile service using the P.2001-2
propagation model (Annex 13).
5.1 System parameters of the mobile service
One incumbent land mobile system is the Governmental Mobile Radio system. The Governmental
Mobile Radio systems enclose several kinds of devices. They are integrated into:
– Land Vehicles.
– Portable Handsets.
– Base stations.
Many of these stations can be operated in Fixed Frequency mode only. Fixed Frequency is thus a
nominal mode to be considered in the compatibility studies.
For the purposes of this Report the Governmental Mobile Radio System is assumed to operate within
the Land Mobile Service as defined in the Radio Regulations.
TABLE 11
System parameters
System Type Governmental Mobile
Frequency tuning range with 25 kHz steps 30-88 MHz
Receiver bandwidth 16 kHz
Protection criteria I/N = –6 dB
Receiver sensitivity –112 dBm @ 10 dB SINAD
24 Rep. ITU-R M.2478-0
TABLE 12
Vehicular parameters
Transmitter/receiver type Vehicle
Antenna height (metres) 2 m
Antenna polarization Vertical
Note: May be slightly tilted
Antenna gain (dBi) –3 dBi
Antenna radiation pattern Omnidirectional
Transmitter output power 0.4 W to 50 W
Out of band emission ITU-R SM.329
Adjacent channel protection 60 dB
TABLE 13
Handset parameters
Transmitter/receiver type Handset
Antenna height (meters) 1.5 m
Antenna polarization Vertical
Note: May be slightly tilted
Antenna gain (dBi) –10 dBi
Antenna radiation pattern Omnidirectional
Transmitter output power 0.2 to 5 W
Out of band emission ITU-R SM.329
Adjacent channel protection 60 dB
TABLE 14
Base station
Transmitter/receiver type Base station
Antenna height (meters) 8 m
Antenna polarization Vertical
Antenna gain (dBi) 2.15 dBi
Antenna radiation pattern Omnidirectional
Transmitter output power 5 to 50 W
Out of band emission ITU-R SM.329
Adjacent channel protection 60 dB
5.2 Minimum coupling loss calculations
Detailed Minimum Coupling Loss (MCL) analysis results on minimum separation distances are
shown in Annex 11 and are summarized below. The following scenarios and parameters are
considered:
Rep. ITU-R M.2478-0 25
– Flat terrain scenarios with 10% and 50% propagation time probability.
– SSB, FM and wide band operation mode for the interfering transmitters, considering the
corresponding antenna heights of 10 m, 20 m and 1 000 m.
– Mobile handset, vehicular and base station receivers as victim of the governmental mobile
system.
Minimum separation distances between the interfering transmitters and the victim receiver are
determined for co-channel, adjacent channels and spurious domain frequencies. A 25 kHz channel
raster is assumed. The results are shown in the Tables below.
Further two considered emission mask options are labelled M1 for Mask option 1 (representing the
emission mask according the ITU-R Recommendations) and M2 for Mask option 2 (with reduced
adjacent channel emission power) please see Annex 11.4.
Evaluated minimum separation distance between amateur stations and governmental radio receivers
are shown in the following Tables. Values are calculated with different amateur station antenna
heights (Htx), for propagation time probability Tpc = 50% and Tpc = 10% and for different operating
radio channels of the governmental radio system.
– Table 15 shows minimum separation distances between SSB and FM amateur station
transmitters and vehicular governmental radio receiver.
– Table 16 shows minimum separation distance between wide band amateur station
transmitters and vehicular governmental radio receiver.
– Table 17 shows minimum separation distances between SSB and FM amateur station
transmitters and handset governmental radio receiver.
– Table 18 shows minimum separation distance between wide band amateur station
transmitters and handset governmental radio receiver.
– Table 19 shows minimum separation distances between SSB and FM amateur station
transmitters and base station governmental radio receiver.
– Table 20 shows minimum separation distance between wide band amateur station
transmitters and base station governmental radio receiver.
TABLE 15
Minimum separation distances between SSB, respectively
FM amateur station and vehicular mobile
Separation distance (km)
Operation mode Tpc Co- channel 1st adjacent channel 2nd adjacent
channel
Spurious
Domain
SSB
Htx = 10 m
10% 435 7.2 7.2 7.2
50% 349 1.2 1.2 1.2
SSB
Htx = 20 m
10% 440 7.4 7.4 7.4
50% 352 1.6 1.6 1.6
SSB
Htx = 1 000 m
10% >500 25.6 25.6 25.6
50% 433 9.9 9.9 9.9
FM
Htx = 10 m
10% 328 149(M1)
65 (M2)
1.3 1.3
50% 238 81 (M1)
27 (M2)
0.4 0.4
FM
Htx = 20 m
10% 332 152 (M1)
67 (M2)
1.1 1.1
50% 241 84 (M1)
29 (M2)
0.4 0.4
26 Rep. ITU-R M.2478-0
TABLE 16
Minimum separation distances between wide band amateur
station and vehicular mobile
Separation distance (km)
Operation
mode Tpc
Co-channel
–6th channel
7th – 12th
channel
16th – 30th
adjacent
channel
Wide Band
Htx = 10 m
10% 260 172 (M1)
70 (M2)
1.7
50% 172 98 (M1)
30 (M2)
1.2
Wide Band
Htx = 20 m
10% 263 176( M1)
73 (M2)
1.7
50% 175 100 (M1)
31 (M2)
1.2
TABLE 17
Minimum separation distances between SSB respectively FM amateur
station and mobile handset
Separation distance (km)
Operation
mode Tpc
Co-
channel
1st adjacent
channel
2nd adjacent
channel
Spurious
Domain
SSB
Htx = 10 m
10% 435 7.3 7.3 7.3
50% 348 1.1 1.1 1.1
SSB
Htx = 20 m
10% 439 7.6 7.6 7.6
50% 352 1.2 1.2 1.2
SSB
Htx =
1 000 m
10% >500 10.5 10.5 10.5
50% 435 9.9 9.9 9.9
FM
Htx = 10 m
10% 328 149 (M1)
62 (M2)
0.9 0.9
50% 237 89 (M1)
25 (M2)
0.35 0.35
FM
Htx = 20 m
10% 331 161 (M1)
65 (M2)
0.9 0.9
50% 240 90 (M1)
27 (M2)
0.35 0.35
Rep. ITU-R M.2478-0 27
TABLE 18
Minimum separation distances between wide band amateur station and mobile handset
Separation distance (km)
Operation
mode Tpc
Co-channel – 6th
adjacent channel
7th – 12th adjacent
channel
16th – 30th adjacent
channel
Wide Band
Htx = 10 m
10% 259 172 (M1)
70.2 (M2)
1.7
50% 172 97.4 (M1)
29.5 (M2)
0.95
Wide Band
Htx = 20 m
10% 262 175 (M1)
72.2 (M2)
1.8
50% 175 100 (M1)
30.6 (M2)
1.2
TABLE 19
Minimum separation distances between SSB, respectively FM amateur
station and mobile base station
Separation distance (km)
Operation
mode Tpc Co- channel
1st adjacent
channel
2nd adjacent
channel
Spurious
Domain
SSB
Htx = 10 m
10% 440 7.7 7.7 7.7
50% 352 1.0 1.0 1.0
SSB
Htx = 20 m
10% 444 7.9 7.9 7.9
50% 357 1.5 1.5 1.5
SSB
Htx = 1 000 m
10% >500 25.7 25.7 25.7
50% 440 2.4 2.4 2.4
FM
Htx = 10 m
10% 332 151 (M1)
64 (M2)
1.1 1.1
50% 240 91 (M1)
27 (M2)
0.35 0.35
FM
Htx = 20 m
10% 335 155 (M1)
68 (M2)
1.1 1.1
50% 245 90 (M1)
27 (M2)
0.35 0.35
28 Rep. ITU-R M.2478-0
TABLE 20
Minimum separation distances between wide band amateur station and mobile base station
Separation distance (km)
Operation
mode Tpc
Co-channel – 6th
adjacent channel
7th – 12th
adjacent channel
16th – 30th
adjacent channel
Wide band
Htx = 10 m
10% 263 176 (M1)
73 (M2)
2.0
50% 175 101 (M1)
33.5 (M2)
1.2
Wide band
Htx = 20 m
10% 267 179 (M1)
75 (M2)
2.1
50% 179 103 (M1)
34.7
1.7
To safeguard interference free governmental radio co-channel operation in 90% of time (Tpc = 10%)
on flat terrain environments, a minimum separation distance of ~440 km between SSB amateur station
transmitter and any type of governmental radio receivers must be respected (average over the three
different governmental receiver types). This minimum distance reduces to a value of 350 km in case
where interference free operation is required only during 50% (Tpc = 50%) of time. Those evaluated
figures are confirmed by both applied methods, MCL and coverage mapping. When considering SSB
amateur station on top of 1000 m mountain, which represents a typical amateur contest situation, then
the minimum separation distance is more than 500 km for 90% of time and ~435 km for 50% of time.
Governmental radio operation in adjacent channels, separated by 25 kHz from SSB carrier, requires
a separation distance of just a few kilometres.
In case of FM amateur stations as interferers, the co-channel separation distances are ~330 km @ Tpc
= 10% respectively ~240 km @ Tpc = 50%. Governmental radio operation in adjacent channels
(separated by 25 kHz from SSB carrier) requires a separation distance of ~90 km @ Tpc =10% and
~40 km @ Tpc = 50% when considering mask option 2. This consideration is justified by the fact,
that FM transmitters do not produce intermodulation distortion but just spurious emissions.
Interference from wide band amateur stations are particularly critical because of the large affected
bandwidth. For interference free governmental radio operation in 90% of time within a bandwidth of
13 channels, a minimum separation distance of 260 km is required. Considering a 25 kHz channels
operational bandwidth for governmental radio operation, a minimum separation distance of ~170 km
is required. The figure for the 25 kHz channel wide interference is based on mask option 1. This
assumption is justified by the fact that spectrum efficient modulation techniques applied for wide
band operation operate a high peak to average power ratio (PAPR) which consequently produces
significant intermodulation interference. However, when reducing the requirement of interference
free operation to 50% of time, the separation distances reduce to ~175 km respectively to ~ 100 km
accordingly.
5.3 Radio Interference coverage mapping
This Report also considered plotting the interference created by an amateur station on a real
geographic map in order to better visualise and interpret the propagation phenomena. To do so, an
amateur station is placed in a given geographical location, and then the amount of interference created
by this station in the adjacent geographical location area is computed and plotted on a map.
Rep. ITU-R M.2478-0 29
Results of the coverage mapping analysis illustrates in a very intuitive way the long interference range
of amateur radio stations and confirm the MCL calculation results also as representative values. All
the results can be consulted in Annex 12. It can easily be recognized on the coverage map results
representation, that in many cases a single amateur station interfere simultaneously with
governmental radio receivers in different European countries.
5.4 A Monte-Carlo simulation of amateur service versus mobile service using the P.2001-2
propagation model
In this section, a study based on a Monte-Carlo approach, aiming to determine to which probability
radio amateurs would interfere with a mobile radio equipment operating in the same geographical
area is discussed. The study is conducted for the different modes intended by amateur radio in this
band, namely: SSB, FM, wideband digital, as described in Table 4. Only interference from the
amateur to the mobile is considered. The study is detailed in Annex 13.
The global Monte-Carlo approach consists in localising a mobile station in a given area with a fixed
operational frequency, and then spread a certain number of amateurs station around it. Those amateurs
are scattered within a certain range according to propagation effects and attributed different frequency
channels (thus different incident power to the victim) and different azimuths. The aggregated
interference to the mobile is then computed. This process is repeated a certain number of times and a
cumulative distribution function is deduced.
The simulations are carried out for two different amateurs’ emission mask. The first one is as
described in Recommendations ITU-R SM.1541-6 Annex 9, ITU-R SM.329-12 and ETSI EN 301 78.
A second option mask has been introduced where additional 15 dB attenuation is considered for the
first floor Out-of-Band (OoB) emissions, in order to better reflect amateurs operation (see § A13.6).
Some separation distances are considered in the simulation for the sake of information. However, one
should note that the application of a separation distance could be very difficult given that the land
mobile has to operate in unknown places without notice.
Simulations have shown that depending on the number of amateur users present inside the simulation
radius, and on the considered protection distance, the probability of interference for the SSB mode
ranges between 3.57 and 86.5%, detailed results are depicted in Table 21. For the FM mode, only one
user is considered inside the simulation radius, and the probability of interference achieves 28.31%,
as depicted in Table 22.
Regarding the WB digital mode, interference is created over a large band affecting a number of
mobile operating channels. When considering a channel raster of 25 kHz for the Land Mobile and a
simulation radius of 70 km, simulations have shown that the probability of interference for the in-
band case (affecting up to 20 mobile channels) can achieve 93.12%. This probability decreases for
the different floors of the OoB emission but stays important for some cases. It is achieves the null
value for the spurious domain. All the results are reflected in Table 23.
30 Rep. ITU-R M.2478-0
TABLE 21
Option mask 2, SSB mode
Number of users inside 200 km circle area
1 2 5 10 14 19
Pro
tect
ion
dis
tan
ce None 8.49% 17.21% 38.18% 62.77% 75.45% 86.5%
10 7.46% 14.35% 31.99% 55.04% 68.47% 80.2%
30 6.35% 11.58% 26.77% 47.78% 61.62% 73.73%
50 5.06% 9.05% 22.86% 41.76% 53.84% 65.82%
70 4.1% 8.57% 19.36% 36.75% 48.12% 58.94%
90 3.59% 6.77% 16.6% 31.56% 42.58% 52.8%
100 3.54% 6.57% 15.33% 29.10% 40.28% 51.1%
TABLE 22
Probability of interference according to the applied protection distance, FM mode, mask
Option 2, only one amateur is active within the 120 km circle area
Protection distance (km) None 10 30 50 70 90
Probability of interference 28.31% 23.7% 16.54% 13.53% 11.35% 9.85%
TABLE 23
Probability of interference according to the applied protection distance, WB digital case
Inband up to
10th channel
1st floor OoB 11th
to 20th channel,
M1|M2
2nd floor OoB 21th to
25th channel
3rd floor OoB 26th to
50th channel Spurious
None 93.65% 78.90%|50.13% 10.81% 3.15% 0.85%
10 km 91.14% 73.15%|37.45% 0.40% 0.01% 0%
30 km 86.37% 55.98%|11.85% 0.04% 0% 0%
50 km 75.92% 38.80%|2.72% 0.01% 0% 0%
5.5 A Monte-Carlo simulation using the CEPT SEAMCAT simulation software
A study based on a Monte-Carlo approach as given in Annex 10 using the CEPT SEAMCAT
modelling software, aims to determine the probability of interference from amateur service
transmitters causing harmful interference to mobile radio links operating in the same geographical
area and on the same frequency of 52 MHz.
The study is conducted for the most common transmission mode (application) used by amateur
operators in the band 50-54 MHz frequency band, namely SSB. The amateur transmitter operates
with an output power of 100 W Peak Envelope Power and the amateur antenna is a Yagi array of
modest gain that is commonly used in the frequency range being considered. The specifications of
the mobile service equipment are the same as those used in the other studies in this Report. Only
interference from the amateur transmitter to the mobile receiver is considered.
Rep. ITU-R M.2478-0 31
The global Monte-Carlo approach consists of localising a mobile service transmitter in a given
location with a fixed operational frequency, and then moving a mobile service receiver around the
mobile service transmitter through a variety of azimuth angles and radial separation distances. The
maximum separation distance between the mobile service transmitter and mobile receiver is based on
mobile transmitter power, mobile receiver sensitivity, antenna height and gain; the maximum
operational distance of the mobile link was calculated to be 40 km.
The interfering amateur service transmitter is free to randomly move around within a 40 km radius
of the mobile service transmitter i.e. anywhere in the mobile transmitter service area. The amateur
service receiver is free to move around within a radial distance of 40 km of each amateur transmitter,
therefore the direction of the amateur link with respect to the victim mobile service receiver will vary
in a random manner.
The Extended-Hata propagation model is used for each service and a protection criterion of
I/N = –6 dB is used for the mobile service link. 20 000 random situations within a variety of
operational scenarios are considered and these operational scenarios are:
– Base station transmitting to vehicle receiver.
– Base station transmitting to handset receiver.
– Vehicle transmitting to base station receiver.
– Vehicle transmitting to handset receiver.
– Handset transmitting to base station receiver.
– Handset transmitting to vehicle receiver.
The results of this study are given in Table 24 below.
The figures quoted in the C/I and C/(N+I) columns are the percentage probability that the scenario
fails to meet the respective signal to noise and signal to noise plus interference ratios while the I/N
column shows the percentage probability that this protection criteria is exceeded.
TABLE 24
Predicted co-channel average interference probability for each study scenario
Link Radius
(km) C/I% (17 dB)
C/(N+I)%
(10 dB)
I/N%
(-6 dB)
Base-to-vehicle 40 2.73 1.78 14.16
Base-to-handset 15 1.11 0.66 6.43
Vehicle-to-base 40 8.73 5.47 38.11
Vehicle-to-handset 3 1.19 0.66 6.45
Handset-to-base 7.5 10.1 6.25 44.65
Handset-to-vehicle 1 3.82 2.44 17.53
5.6 Sharing possibilities
New and existing applications of the amateur service using this frequency band are assumed to be of
fixed or nomadic type. It is assumed, that the new amateur service application ‘infrastructure’ and the
application ‘repeater’, which requires the largest portion of bandwidth, are of fixed type.
32 Rep. ITU-R M.2478-0
Values for the parameters “Fraction of time transmitting within a single session”, “Session Duration”
as well as the values for the amateur station density are different for the both use cases A and B as
defined in the section “spectrum needs”.
It can be concluded, that because of low active amateur station density for SSB and FM, low session
durations as well as relatively narrow bandwidth for both applications, sharing of those two
applications with the mobile service may be possible in the average use case.
Sharing with mobile service and wide band modes in average use case may be possible, because of
low station density and low session duration. However careful evaluation of sharing conditions need
to be done.
Sharing with mobile service and Repeaters during average use case may cause problems because of
long session duration and higher range.
Under the conditions described in Table 9, sharing between the application ‘infrastructure’ and the
mobile service in the average use case is not feasible: The very high session durations, large
bandwidth and interference range of up to 172 km (for 50% of propagation probability), causes high
interference probability. In can be concluded, that in the average use case a single infrastructure
station causes interference with a level above the protection criteria I/N = –6 dB (as used in the study)
in an area of more than 92 000 km2. In the average use case there is about one infrastructure
transmitter operating in an area of the size of Switzerland. It should be noted, that the interference
occupies a bandwidth of 12 mobile service channels in co-channel scenarios. Considering adjacent
band interference, 36 mobile service channels would be interfered in a range of 30-170 km, dependent
on mask option and propagation channel time probability. It should further be noted that within the
coverage range of the ‘infrastructure’ transmitter of 70 km the protection criterion I/N = –6 dB is by
far exceeded. An area with a radius of 70 km may represent a significant fraction of the area of some
countries.
Sharing with SSB in use case where additional spectrum is required may be possible due to the very
limited session duration and the relatively narrow bandwidth.
All the above mentioned sharing situations are summarized in the Table 25.
TABLE 25
Sharing options considering different amateur radio applications and
the two use cases “Average and additional spectrum required”
Option Usage
situation Applications
Amateur
population
density
Required
Spectrum (MHz)
(Needs Study 1)
Spectrum
needs in %
of time
Sharing
1 Case A SSB, FM, WB average 0.534
98% May be possible high 0.546
2 Case B SSB, FM, WB average 0.765
2% May be possible high 1.002
3 Case A SSB, FM, WB,
Repeaters
average 0.634
98%
May be possible
(conditions to
be defined) high 0.746
4 Case B SSB, FM, WB,
Repeaters
average 0.865
2%
May be possible
(conditions to
be defined) high 1.202
Rep. ITU-R M.2478-0 33
TABLE 25 (end)
Option Usage
situation Applications
Amateur
population
density
Required
Spectrum (MHz)
(Needs Study 1)
Spectrum
needs in %
of time
Sharing
5 Case A
SSB, FM, WB,
Repeaters,
Infrastructure
average 1.034
98% Not possible high 1.246
6 Case B
SSB, FM, WB,
Repeaters,
Infrastructure
average 1.365
2% Not possible high 1.702
Different countries are operating governmental communication systems of mobile and nomadic types
in the frequency band 50-54 MHz. New and existing amateur service applications are using the
frequency band of 50-54 MHz as fixed as well as nomadic type will exceed the –6 dB I/N protection
criteria over several hundred kilometres and multiple mobile channels. Therefore coordination is very
difficult or not possible. Harmful interference probability with wide band applications is significantly
higher than with SSB, in particular due to the very high occupied bandwidth and adjacent channel
interference.
There is no technical reason identified, why amateur stations need the same level of protection than
governmental communication in the mentioned interference situation. Therefore a frequency
assignment to the amateur service in a portion of the 50-54 MHz frequency band on a secondary basis
seems to be reasonable.
For the application “infrastructure”, no e.i.r.p. value is known. A service area for this application of
15 393 km2 respectively a range of 70 km is assumed. For the application “wide band mode” a range
of 40 km is assumed. The reason for the long range of the infrastructure application is unclear. It
could be explained by extreme antenna height, antenna gain or increased TX power. However it can
be concluded that the interference range of the infrastructure application is larger than the interference
range of the wide band mode.
It should be noted, that any mobile receiver located within 70 km of the amateur infrastructure
transmitter experiences an unwanted signal which exceeds the protection criterion of –6 dB I/N by
16 dB or more.
5.7 Summary of conclusions
A study using Minimum Coupling Loss analysis shows very long interference ranges for some type
of amateur service applications. Due to different usage patterns and activities of the different
applications, sharing is not only dependent on the interference range. It is shown, that use of the
current SSB application in average situations has low to moderate impact on mobile service and can
therefore be shared. On the other hand, applications occupying very large portion of the bandwidth
and transmitting in networks with high duty cycle, such as the ‘infrastructure’ application, cannot
coexist with the mobile service. It should be noted that within the coverage range of the
‘infrastructure’ transmitter of 70 km, the protection criterion I/N = –6 dB is by far exceeded. An area
with a radius of 70 km may represent a significant fraction of the area of some countries. Repeaters
may be shared under certain sharing conditions which need to be defined.
One Monte-Carlo study has shown that given the amateur density and usage activity provided in
§ 3.7, the probability of inference caused by the amateur service to the land mobile service is very
high in the case of co-channel usage. This probability decreases for adjacent channel usage, but still
remains above tolerable percentages.
34 Rep. ITU-R M.2478-0
Another study in Annex 10 using SEAMCAT Monte-Carlo simulation shows the predicted
probability of interference and service degradation for the scenarios in Table 25. The Monte-Carlo
simulations indicate that the probability of interference between the amateur service and mobile
within is very high in the case of co-channel operation if both services operate within the same or
adjacent service areas.
Results of the coverage mapping analysis in Annex 12 illustrates in a very intuitive way the long
interference range of amateur radio stations and confirm the MCL calculation results also as
representative values. It can easily be recognized on the coverage map results representation, that in
many cases a single amateur station interfere simultaneously with governmental radio receivers in
different European countries.
6 Sharing with the fixed service
In the European Common Allocation table there is no allocation to the fixed service in the 50-54 MHz
frequency band though there may also be fixed usage in Region 1 which has not been notified to the
MIFR, which may include short range fixed use on a national basis.
Given the likely small number of affected sites in Region 1 it is expected that, if required, any
interference can be dealt with on a case by case basis. An analysis of the details of the notifications
shows that the assignments are generally FM stations with characteristics similar to stations of the
mobile service so similar protection and interference mitigation schemes could be applied to fixed
service stations if required.
7 Sharing with the radiolocation service
7.1 Background
In the frequency band 46-68 MHz, RR No. 5.162A provides an additional allocation to the
radiolocation service on a secondary basis in a number of countries and is limited to the use of wind
profiler radars.
7.2 Study details
The detailed study is contained in Annex 14; the propagation model used is E-Hata (rural) at 52 MHz
(median case).
7.3 Study results
The calculations show that typical separation distance between Amateur service systems and Wind
profiler would range from 30 km to 300 km, confirming the need for specific protection measures.
7.4 Regulatory aspects
Taking into account the low number of WPRs and the low number of amateur systems in their
vicinity, sharing could probably be considered on a case-by-case basis.
The relevant procedure would need additional consideration providing that the status of the new
allocation to the amateur service provides the radiolocation service equality of precedence to the
amateur service.
Rep. ITU-R M.2478-0 35
8 Sharing with the broadcasting service
Annexes 5, 6 and 7 contain the detailed sharing studies which cover sharing between the amateur
service and the broadcasting service. Annex 8 contains details of current and past sharing
arrangements used in some countries.
8.1 Sharing study details
Annexes 5, 6 and 7 provide details of the studies undertaken to determine if the amateur service can
share with the broadcasting service in Region 1 in the 50-54 MHz frequency band.
Study 1 (Annex 5) considers the maximum permissible amateur field strength at the TV receiver to
avoid harmful interference using the relevant ITU-R Recommendations.
Study 2 (Annex 6) are Monte-Carlo simulations which provide statistical estimates of the likelihood
of interference between the amateur service and the broadcasting service for two situations:
– A major metropolitan area with a high powered TV broadcast transmitter.
– A small rural township serviced by a relatively lower power transmitter.
Study 3 (Annex 7) provides details of the likelihood of interference between the amateur service and
the broadcasting service using an electromagnetic compatibility (EMC) approach.
8.2 Study 1 description
The minimum field strength for which protection against interference is provided in planning should
never be lower than 46 dBµV/m from Table 1 of Recommendation ITU-R SM.851-1.
Remaining analogue television transmitters in Region 1 generally utilise the SECAM System D/K
standard with a channel centre frequency of 52.50 MHz, vision carrier frequency 49.75 MHz and
sound carrier 56.25 MHz. Carrier offsets may be used.
The method (detailed in Annex 5) involves calculating the difference between the wanted TV signal's
field and the field resulting from an amateur transmitter operating on a frequency within the TV
channel some distance away from the edge of the TV service area. If the amateur signal is less than
the minimum signal strength based on the minimum required TV signal field strength adjusted for
the protection ratio, then no harmful interference will occur.
8.3 Study 1 results
This study shows that sharing is possible using the method described without any harmful interference
occurring from an amateur transmitter with a power level (e.r.p. of 30 dBW) at a distance of 50 km
from a television transmitters’ service area in the frequency band 50-54 MHz.
This study details a method (see Annex 5) of ascertaining whether a rather basic sharing scenario will
likely protect remaining analogue television broadcasting applications in Region 1 in the band
50-54 MHz, until this band is no longer used for broadcasting.
8.4 Study 2 description
This study considers two typical scenarios:
– A major metropolitan area with a high powered TV broadcast transmitter.
– A small rural township serviced by a relatively lower power transmitter.
Two propagation models were used in the simulations, with the most appropriate model selected for
each service:
36 Rep. ITU-R M.2478-0
– For the TV broadcasting service ‘ITU-R P.1546-4 Land’ with the analogue broadcasting
option selected and signal strength calculations are for between 10% and 50% of the time.
ITU-R P.1546 calculations are only valid for field strengths exceeded for percentage times
in the range from 1% to 50%.
– For the amateur service the ‘Extended-Hata’ model was used.
For further details please see Annex 6.
For the TV receiver, the required protection ratio of wanted to unwanted signal strengths (C/I) is
54 dB. The sensitivity of the TV receiver is –48 dBm (~1 mV into 50 Ohms) and the bandwidth of
the TV signal is assumed to be 5 MHz.
The TV receiving antenna used in the study is a low gain design which is ‘built in’ to SEAMCAT
and it would be suitable for short to medium range reception of TV signals; however it is likely, and
experience suggests, that receivers on the outskirts of the TV coverage area will use antennas with
higher gains and more directional characteristics which will reduce the potential for interference from
any directions other than the main lobe that will be pointing towards the TV broadcast transmitter
antenna.
The study assumes two amateur stations operating anywhere within a 50 km radius of the TV
broadcast transmitter. The two amateur stations have a 100 W transmitter and use four-element Yagi
antennas at 10 m elevation and are operating on a 5% duty cycle. The amateur transmitters may be
communicating to receivers either inside or outside of the TV service area. All the parameters used
by SEAMCAT are given in Table A6.3.
8.5 Study 2 results
The results of Study 2 are given in Tables A6.1 and A6.2 where the probability of interference and
signals strengths are given. Table 26 provides a summary of the calculated probability of interference
for the two cases considered in the study:
TABLE 26
Probability of interference for the major city calculated by SEAMCAT using
the parameters given in Table A6.3. The C/I column is the calculated
percentage of interference for the C/I protection criteria of 54 dB
Study Probability of interference
(C/I exceeds protection limit)
Case 1: Major metropolitan station – Suburban 0.14%
Case 1: Major metropolitan station – Rural 0.81%
Case 2: Regional station 1.57%
8.6 Study 3 description
A deterministic approach to evaluate interference impact of amateur stations on the coverage area of
broadcasting stations was used (for details see Annex 7). In the band 50-54 MHz maximum acceptable
field strength from amateur stations at the border of analogue broadcasting coverage area was
calculated based on the Recommendations ITU-R M.851, ITU-R ВТ.417 and ITU-R ВТ.1368.
Different interference cases between amateur service stations, with parameters corresponding to
Recommendation ITU-R M.1732, and existing TV broadcasting stations were considered. For two
type of amateur stations (portable station with antenna height of 2 m and fixed station with antenna
Rep. ITU-R M.2478-0 37
height of 15 m) single interferer and multiple interferer (from six amateur stations) impact on the TV
broadcasting coverage area were calculated in accordance with Recommendation ITU-R P.1546.
The calculation of electromagnetic compatibility is based on the application of Recommendation
ITU-R SM.851-1 – Sharing between the broadcasting service and the fixed and/or mobile services in
the VHF and UHF bands, and Recommendation ITU-R P.1546 – Method for point-to-area predictions
for terrestrial services in the frequency range 30 MHz to 3 000 MHz.
The calculation assumptions used:
– In the frequency band 50-54 MHz, the characteristics of amateur service stations are taken
from Recommendation ITU-R M.1732-2 – Characteristics of systems operating in the
amateur and amateur satellite services for use in sharing studies mobile service stations;
– At is the factor that determines amateur service stations’ antenna selectivity. In calculations
in accordance with Recommendation ITU-R P.1546, the amateur service station antenna's
directivity is taken into account for each direction of transmission as the e.i.r.p. is re-
calculated based on the antenna pattern radiation reductions. For non-directional antennas At
is assumed to be 0 dB;
– Ol is the propagation loss resulting from the limited size of the Fresnel zone. The calculation
assumes 0 dB, since losses due to irregular terrain have already been addressed in the
calculation, and the boundary of the TV broadcasting area is not in built-up areas;
– Cp is a factor that accounts for polarization discrimination of the broadcasting service station
and amateur service station antennas;
– Here and hereinafter, TV stations’ reception area boundary locations affected by interference
from amateur service stations are determined through calculations of the area with an
interference level of 6 dBμV/m at a height of 10 metres with tropospheric interference (10%
of the time) and –4 dBμV/m for continuous interference (50% of the time).
The maximum interference is calculated by using the formula:
Еint_max = Tfs-N-At-Ol-Cp-Ad-PR
where Tfs is the minimum wanted field strength of the broadcasting service station in the frequency
band 48.5-56.5 MHz, determined in accordance with Recommendation ITU-R SM.851-1.
8.7 Study 3 results
The calculations showed that maximum acceptable field strength from amateurs stations are 6 dBμV/m
at a height of 10 metres with tropospheric interference (10% of the time) and –4 dBμV/m for continuous
interference (50% of the time).
For the portable amateur stations (antenna height of 2 m) and fixed amateur stations (antenna height
of 15 m) the necessary separation distances between edge of broadcasting coverage area and amateur
stations varies from 70 km to 175 km. At smaller distances between amateur station and broadcasting
coverage area, e.i.r.p. of amateur stations needs to be reduced to ensure protection of the considered
broadcasting stations.
The results of this study are visualized as a number of maps which show signal strength contours in
Figures A7.3 through A7.12.
The study results show that the amateur service stations’ field strength values at the test points exceed
the previously determined threshold that supports interference-free operation of the broadcasting
service stations, which equals 6 dBμV/m.
38 Rep. ITU-R M.2478-0
Values by which the field strength threshold is exceeded and the frequency and territorial separations
required depend on the characteristics and relative location of the amateur service stations and TV
broadcasting station.
Thus, to compensate for the level of interference on the boundary of the TV broadcasting station’s
reception area, additional restrictions should be imposed on amateur service stations’ e.r.p. in the
direction of the boundary of the TV broadcasting station’s reception area, with the e.r.p. reduced to
values below 0 dBW.
The necessary protection distances vary from 70 km to 175 km.
8.8 Summary of study results
Sharing between analogue television and the amateur service is not new in this frequency band. Annex
8 provides information concerning current and past sharing arrangements for the amateur service and
other services in the 50 MHz frequency band.
The Studies 1 (Annex 5) and 3 (Annex 7) are based on the minimum coupling loss method, protection
of minimum wanted field strength of the broadcasting station equal to 46 dBµV/m according to the
Recommendation ITU-R SM.851-1 and maximum amateur stations e.i.r.p. of 28-30 dBW. Depending
on the used assumptions the calculated separation distances vary from 50 km (Study 1) up to 175 km
(Study 3).
The Study 2 (Annex 6) based on the Monte Carlo method and considered amateur stations power of
100 W and assumption that two amateur stations operating anywhere within a 50 km radius of the
TV broadcasting station. For used C/I protection criteria of 54 dB calculated interference (to
broadcasting station) probability vary from 0.14% (major metropolitan TV station) up to 1.57%
(regional TV station).
The differences in the results and its reasons could be explained by the following:
– For Study 1, the assumptions given in Table A5.2 are an optimistic scenario taking into
account a number of discriminations and attenuations simultaneously on the path between
potential interferer and the broadcast receiver. This leads to potentially underestimate the
required separation distance.
– For Study 2, the concept of duty cycles and the presentation of a result as “interference
probability” is not always suitable for use in broadcasting unless the quality of required
reception conditions per hour is also taken into account.
– The Study 3 is based on the method which closer corresponds practice in ITU-R in
broadcasting sharing and compatibility studies with other services, for example the
application of Recommendation ITU-R SM.851.
Taking into account the results of the conducted studies and difficulties of defining a single necessary
separation distance between amateur and broadcasting stations, the appropriate condition for
protection of the broadcasting station from harmful interference, would be that a field strength from
an amateur station at the edge of the service area of a broadcasting transmitter shall not exceed 6
dBμV/m for 10% of the time at a height of 10 m above ground.
It also should be noted that harmful interference to broadcasting television reception arising from the
Amateur service is likely to be intermittent and therefore difficult to trace to the originating station
of the Amateur Service. So any harmful interference which does occur will need to be handled
bilaterally between concerned administrations, particularly in line with Regional Agreements done at
Stockholm in 1961 (for the European Broadcasting Area) and at Geneva in 1989 (for the African
Broadcasting Area).
Rep. ITU-R M.2478-0 39
If digital television technologies are introduced in the 48-56 MHz band, additional compatibility
studies will be required to develop conditions for the sharing of amateur and broadcasting stations in
the band 50-54 MHz.
9 Mitigation Factors
Concern has been expressed regarding the feasibility of sharing between the amateur service and
incumbent services featured in sharing studies especially in relation to the broadcasting service
(analogue television) and land mobile service (governmental systems). It is therefore necessary to
examine the possibility of introducing mitigation measures particularly in areas of Region 1 where
there is a high density of amateur service licensees.
In terms of the avoidance of harmful interference in Region 1 the most critical geographical area with
the highest density of amateur licensees is Europe. Most of the concern expressed by administrations
appears to apply to the 52-54 MHz frequency band. The lack of concern with respect to the 50-52
MHz frequency band, where most European administrations have provided for amateur usage, using
existing applications, under Article 4.4 of the Radio Regulations (see § 2.1 and Table 1 above). It is
believed that in practice there have been minimal cases of harmful interference reported.
In administrations where such use is allowed, the following characteristics of the infrastructure
applications such as propagation beacons, voice repeaters, simplex gateways and some data systems
could facilitate the sharing of the band 50-52 MHz between the amateur and other services:
– Such stations are licensed by a national administration with technical characteristics specific
to an individual station.
– They have fixed and published locations.
– Their choice of channels and location are coordinated as part of their licensing process with
the express intention of avoiding interference.
– They are typically restricted to lower output or radiated power compared to standard
individual amateur licences and may have other parameters in their licences including
automatic call-sign identifiers, etc.
– They typically may also require contact lists of responsible persons and remote control
facilities to be maintained, to facilitate spectrum management or rapid closedown.
The same mitigation measures could also apply to many wide-band digital applications envisaged for
the 50-54 MHz frequency band. These mitigation measures might be implemented on a national, sub-
regional or regional basis to remove the possibility of harmful interference to incumbent services in
the 50-54 MHz frequency band. See also A1.12 to A1.16.
It should be noted that none of the techniques mentioned above have been included in the sharing
studies to test their efficiency by simulation or experimentation for the bands studied under WRC-19
agenda item 1.1. Operational experience shows that these measures have been effective under RR
No. 4.4 operations in the 50-52 MHz with some existing applications. These techniques have not been
studied for new applications in this band under agenda item 1.1.
10 Conclusion of the Report
10.1 Study components
This Report addressed the invitation in the Resolution 658 (WRC-15) to evaluate the amateur service
spectrum needs in the band 50-54 MHz and to conduct sharing studies between the amateur service
and the incumbent mobile, fixed, radiolocation and broadcasting (TV) services, in Region 1, under
40 Rep. ITU-R M.2478-0
WRC-19 agenda item 1.1. This Report mainly considers the European context in accordance with the
received contributions.
10.2 Spectrum needs
The evaluation of spectrum needs is shown to be dependent on the amateur population density, type
of application and assumed usage patterns, with the result being that the calculated spectrum needs
varies significantly between studies.
A first study has shown that in exceptional high use cases, the spectrum need is about 1.7 MHz in
European Countries with high population density. A second study has shown that the spectrum need
is around 4 MHz (in European countries with an average amateur density population), and can reach
up to 10 MHz. According to a third view, 200 kHz would satisfy the spectrum needs of the amateur
service in Region 1.
Based on the result of the studies, a Region 1 allocation to the amateur service may be considered in
part or all of the 50-54 MHz.
10.3 Sharing with the mobile service
Protection distances up to 400 km may be required for co-channel operation with decreasing distances
for increasing frequency spacing, to respect the –6 dB I/N protection criterion in case of one amateur
application. For the proposed amateur service infrastructure applications, the protection criteria is
exceeded by 16 dB or more simultaneously on more than 10 mobile channels in a range of 70 km. An
area with a radius of 70 km may represent a significant fraction of the area of some countries.
Monte-Carlo simulations indicate that the probability of interference between the amateur service and
mobile service is very high in the case of co-channel operation if both services operate within the
same or adjacent service areas.
10.4 Sharing with the broadcasting service
Sharing studies with the broadcasting service have shown that adequate protection of the broadcasting
service requires that the amateur service stations’ field strength values do not exceed 6 dBμV/m for
more than 10% of time along the border of a country with operational analogue broadcasting stations,
measured at a height of 10 m above ground. The 6 dBµV/m field strength limitation means that a
separation distance of up to 175 km may be required from the potentially affected TV transmitter
with an alternative being a reduction in the allowed amateur transmitter power. Given that the 175
km distance may in some cases be beyond national boundaries some form of coordination between
affected states may be required.
10.5 Sharing with the radiolocation service
In the frequency band 50-54 MHz, the radiolocation service is restricted to wind profiler radar (WPR)
systems. Sharing studies indicate that separation distances of 30 to 300 km may be required between
WPR systems and stations of the amateur service. Taking into account the limited numbers of systems
in or immediately adjacent to, the 50-54 MHz frequency band, sharing could probably be considered
on a case-by-case basis using local arrangements to solve any interference problems. Any regulatory
procedures to ensure that the status of the radiolocation service has precedence over any new
allocation to the amateur service will need additional consideration.
10.6 Status of allocation
Based on the result of the studies, the status of any new Region 1 allocation to the amateur service in
part or all of the 50-54 MHz frequency band should ensure the protection of, and avoid placing any
Rep. ITU-R M.2478-0 41
additional constraint on, the incumbent Region 1 primary and secondary services in the band.
Appropriate regulatory actions may be required to maintain the current equilibrium between services
in the band in Region 1.
Annex 1
Spectrum needs and associated information
A1.1 Introduction
Section 3 of this Report addresses the spectrum needs element of WRC-19 agenda item 1.1
concerning the frequency band 50-54 MHz. Annex 1 provides additional detail concerning the
application-based method and the background to the requirement for a globally harmonised allocation
in the frequency band 50-54 MHz.
A1.2 Regulatory history
The first administrative radiocommunication conference was held simultaneously with the
Administrative Telegraph and Telephone Conference in Cairo, 1938 under the banner of the
International Telecommunication Conferences. In the European Region as well as other regions radio
amateurs had access to the frequency band 56-60 Mc/s which was harmonically related to other
amateur allocations in lower frequencies (e.g. 28-30 Mc/s).
The subsequent International Radio Regulations were developed at the Atlantic City Conference in
1947. These regulations reflected the great advances made in the development of television
broadcasting with the band 41-68 Mc/s being allocated to the broadcasting service in Region 1. In
Regions 2 and 3 the band 44-50 Mc/s was allocated to the broadcasting service along with 54-72 Mc/s
in Region 2 and 54-70 Mc/s in Region 3. This clearly shows the origins of the current frequency
allocation of 50-54 MHz in Regions 2 and 3 which replaced the original 56-60 Mc/s allocation,
leaving amateurs in Region 1 without frequencies to conduct experimentation in this unique part of
the radio spectrum.
NOTE – Mc/s is used because the text is from the original Radio Regulations.
A1.3 Current and future regulatory issues
Recommendations 1 and 2 of Recommendation 34 of the Radio Regulations (version of 2016) are
particularly relevant e.g. that future world radiocommunication conferences:
1) should, wherever possible, allocate frequency bands to the most broadly defined services
with a view to providing the maximum flexibility to administrations in spectrum use, taking
into account safety, technical, operational, economic and other relevant factors;
2) should, wherever possible, allocate frequency bands on a worldwide basis (aligned services,
categories of service and frequency band limits) taking into account safety, technical,
operational, economic and other relevant factors.
A1.4 General information about the amateur service
The amateur service, with more than three million operators worldwide, continues to grow. Radio
amateurs utilise frequency allocations to the amateur service to engage in two-way communications,
42 Rep. ITU-R M.2478-0
scientific and technical investigation and experimentation. In addition amateurs provide
communication in the wake of natural disasters, provide non-commercial public service
communications, conduct other activities to advance technical education, develop radio operating
technique and enhance international goodwill.
The 50-54 MHz frequency band is allocated to the amateur service in Regions 2 and 3. While the Region
1 African countries listed in No. 5.169 of the Radio Regulations (RR) have an allocation to the amateur
service in the 50-54 MHz frequency band on a primary basis, a number of other Region 1 countries
have authorised the use of all or part of the 50-52 MHz frequency band by the amateur service on a
mainly secondary (but sometimes national primary) basis in accordance with RR No. 4.4.
A1.5 CEPT Provisions in Region 1
CEPT’s European Table of Frequency Allocations allocates the 50-52 MHz frequency band to the
amateur service on a secondary basis. As of October 2016, twenty-four of the forty-eight member
administrations of CEPT have notified an allocation to the amateur service in the CEPT European
Communications Office’s online Frequency Information System (EFIS). In addition, a further twelve
CEPT administrations have indicated that amateur usage is an application in this band. This
demonstrates that 75% of CEPT’s membership authorise amateur usage within the 50-52 MHz
frequency band. The permitted maximum transmitter power of such stations is mostly 100 W, in some
countries there are territorial limitations with regard to power and frequencies.
A1.6 Article 5 – VHF Amateur Spectrum Shortfall in Region 1
The opportunity provided by WRC-19 AI 1.1 to achieve global spectrum harmonisation would
provide the means to introduce new and innovative communications applications for the amateur
service. Additionally the amateur service sees a need to bridge the very wide gap between the existing
allocations at 28 MHz and 144 MHz in Region 1 thus avoiding the use of RR No. 4.4 by those
administrations in Region 1 not party to RR No. 5.169 which have provided at a national level an
allocation to the amateur service within the 50-54 MHz frequency range. Furthermore, access to the
entire 50-54 MHz frequency band would help to compensate for the possible loss of spectrum identified
for IMT in the 2.3 GHz and 3.4 GHz frequency bands at recent WRCs. It would also ease problems
experienced by the amateur service caused by the widespread rise in background noise in the MF and
HF spectrum which increasingly renders lower frequencies allocated to the amateur service subject to
disturbance and harmful interference, particularly in urban environments.
Unlike Region 2 and in some cases Region 3, the amateur service in Region 1 does not have
allocations elsewhere in the VHF range at 146-148 MHz and 220-225 MHz; harmonisation with
Regions 2 and 3 in the 50-54 MHz frequency band would therefore additionally seem appropriate,
especially if global amateur networks are to be realised.
In the range 30-300 MHz the amateur service in most of Region 1 currently has access to only 2 MHz,
in most of Region 2 amateurs currently have access to 13 MHz and in most of Region 3 amateurs
currently have access to 8 MHz of VHF spectrum.
A1.7 Detailed 50 MHz band usage and propagation mechanisms relevant to the Amateur
Service
In common with all allocations to the amateur service the International Amateur Radio Union (IARU)
has developed a utilization plan to facilitate intercommunication and technical investigations in the
50 MHz range. IARU band plans are generally flexible and are regularly reviewed in order to reflect
technical developments and user requirements. For example in 2011 the range 50.0-50.5 MHz was
the subject of detailed re-planning and beacon upgrades in Region 1 to accommodate demand and
Rep. ITU-R M.2478-0 43
technology advances. Such reviews can be expected to continue as technology and amateur ingenuity
evolves.
Based on a background of existing usage and anticipated growth in digital systems, it is necessary to
determine spectrum needs based on the following application categories within the range 50-54 MHz.
TABLE A1.1
Application categories in the 50-54 MHz frequency range
Designated application categories
Typical
Distance2
(km)
Frequency
range
(MHz)
Narrowband weak-signal communications e.g. CW, SSB & digital
weak signal data modes.3
250 50.0-50.5
24/7 propagation beacons
Relatively narrowband (≤ 25 kHz) digital voice, FM voice, data. 70 50.5-52.0
Repeaters and gateways 100
Wider bandwidth predominantly digital applications (see
Annex 1.3)
40 52.0-54.0
A1.8 Propagation
Table A3.1 details the principal frequency bands used by the Amateur Service in Region 1. Radio
wave propagation falls into three categories: ground wave, direct wave and skywave. At frequencies
above 144 MHz, direct wave is the usual mode of propagation for communications requiring good
quality communications. Emissions in HF (3-30 MHz) spectrum as well as high MF and low VHF
spectrum in the range 1.5-70 MHz can travel great distances over land and even greater distances
over sea water for percentages of time which vary according to daily (daylight or darkness), seasonal
(summer or winter) and cyclical (11 year solar cycle) variations.
Nevertheless if sufficient spectrum is available in the HF range for users, skywave propagation should
be able to provide single hop communications to span distances as great as 3 000 km. Multi-hop or
chordal hop propagation can also utilised if propagation conditions permit, particularly when solar
flux is high.
Skywave propagation occurs when the radio wave is refracted in the ionosphere. At altitudes between
50 and 400 km, ultraviolet light from the sun ionizes air molecules, creating a layer of free electrons
that sharply bends incident HF radio waves back to the Earth. HF spectrum is required for reliable
skywave propagation because lower frequencies tend to be absorbed by the ionosphere and higher
frequencies tend to penetrate the ionosphere.
The ionosphere has four layers:
The D layer occupies the region from of 50 to 90 km above the earth and exists only during daylight
hours. The D layer completely absorbs medium frequencies (e.g., the 1.8-2.0 MHz band) and weakens
high frequencies through partial absorption.
2 Same as ‘typical service area radius’ used in calculations.
3 ‘Weak signal modes’ are structured for very basic communications with low data rate and narrow bandwidth
for best weak signal performance.
44 Rep. ITU-R M.2478-0
The E layer exists at a height of roughly 110 km and is responsible for most daytime HF skywave
propagation at distances less than 1 500 km.
Between 175 and 250 km the F1 layer, exists only during the day. It is occasionally used for daytime
skywave propagation, but transmissions that penetrate the E layer often penetrate the F1 layer too
(with additional absorption).
The F2 layer, at 250 to 400 km is the main ionospheric layer for long-distance HF radio
communications. It exists day and night, but there are significant altitude and electron density
variations by day, season and sunspot cycle.
Depending on the electron density at each layer, there is a critical highest frequency (CF) at which
the layer reflects a vertically incident wave. Frequencies higher than the FC pass through the layer at
vertical incidence. Frequencies below the FC are reflected back from the ionosphere.
Absorption is least at frequencies near the maximum usable frequency (MUF), so frequencies just
below the MUF are most desirable. HF frequency planning is a complicated process that involves
different optimal frequencies depending on the path length, time of day, season and sunspot cycle.
The challenge is complicated by the fact that the optimal frequency changes rapidly at day/night
transitions, and for long east-west links, the two ends see sunset and sunrise hours apart. It often is
the case that the optimal frequency simply is not available because it is already in use. As a
consequence HF skywave communications invariably operates with sub-optimal parameters.
If it is desirable to use HF for short links, frequencies at 3.5 MHz, 5.3 MHz or 7.1 MHz are sometimes
feasible. In particular spectrum users will likely operate at near vertical incidence skywave (NVIS)
with antennas that focus their main lobe vertically.
Concerning the bands available to the amateur service below 50 MHz; because of propagation
variations dependent on time of day, summer or winter and high or low solar flux levels the
frequencies listed in Table A3.1 are unlikely to usable at any geographical location on a twenty four
hours a day, seven days a week basis. However at times of high solar flux and minimal geomagnetic
disturbances near the 11 year solar maximum there is a general increase in amateur radio activity
when the higher HF bands above 14 MHz support inter-continental communications for longer
periods of time. It is for the foregoing reasons that stations monitoring HF Amateur Service frequency
allocations will detect minimal activity at certain times. At such times allocations adjacent to Amateur
Service allocations will also appear to be under-utilised.
The frequency band 144-146 (148 in Region 2) MHz supplements the direct wave Amateur Service
usage that is found in the frequency band 50.5-52 (54 in Region 2) MHz. There is an urgent need to
provide alternative spectrum for broadband direct wave communications previously implemented in
the frequency bands 430-440 MHz, 1 240-1 300 MHz and 2 300-2 450 MHz.
The following paragraphs focus on propagation issues directly related to the 50-54 MHz frequency
band.
The frequency range 30-80 MHz marks the transition area between ionospheric and non ionospheric
propagation modes, which makes it particularly interesting for communication, experimentation and
study within the amateur service. A number of propagation modes are used by amateurs in the range
50-54 MHz:
– Free-space (line of sight)
– Sporadic-E ‘clouds’
– E and F2 multi-hop and chordal-hop
– Trans-equatorial spread-F
– E-layer Field Aligned Irregularities (FAI)
Rep. ITU-R M.2478-0 45
– Aurora backscatter
– Meteor scatter
– Earth-Moon-Earth (using the moon's surface as a passive reflector).Tropospheric super-
refraction and ducting
– Tropospheric scatter
– Scatter from aircraft and objects in near Earth orbits (e.g. International Space Station).
An allocation within this frequency range in Article 5 of the Radio Regulations has not been generally
available to the amateur service in Region 1 for well over half a century. Alignment with Regions 2
and 3 would facilitate the general understanding and prediction of propagation events as data
accumulates and more Region 1 administrations grant their amateur licensees access to spectrum in
the 50-54 MHz frequency band. Therefore, longer-term propagation studies would continue and
thrive.
A1.9 50-52 MHz band usage
At present, in the 50-52 MHz frequency band, the most common analogue and digital applications to
date use bandwidths of less than 25 kHz, within which long distance weak-signal and propagation
beacon applications are globally coordinated in the segment 50.0-50.5 MHz. This frequency range
would derive great benefit from harmonisation with Regions 2 and 3. The essential requirement is
500 kHz of spectrum for narrowband applications including propagation beacons.
The frequency range 50.5-52 MHz is currently utilised for two-way voice communications using
frequency or phase modulation, data, gateways and FM repeaters. Digital voice and data is already
being used for 50 MHz networks in the amateur service incorporating text and simple voice
messaging. Such systems have already shown to be of considerable value in emergency
communications on other frequency bands. See RR No. 25.3.
The segment 50-52 MHz would therefore be utilised to satisfy current and continuing analogue/digital
usage and developments on a global basis. The 50-54 MHz frequency band is well supported by
amateur developers, including those employing the latest Software Defined Radio (SDR) techniques,
partly as a consequence of the entire frequency band 50-54 MHz being allocated in RR Article 5 in
ITU Regions 2 and 3 and part of Region 1. Thus growth in digital modes can be expected to continue
in the existing 50-52 MHz range, assisted by 52-54 MHz developments and vice versa.
A1.10 52-54 MHz band usage
In those Region 1 countries where 52-54 MHz (or parts thereof) is allocated, its use is designated for
wide band applications an area where significant innovation, growth and benefits are forecast, should
it become more generally available in Region 1. 52-54 MHz is also needed to satisfy the wider
bandwidths and data rates of advanced digital application scenarios and is currently planned on the
basis of up to 4 × 500 kHz blocks which may be sub-divided or merged to suit digital applications.
There would be no aggregation of spectrum, thus the maximum band width would be 500 kHz. IARU
has updated its band plan accordingly. A and C would be reserved for narrow band modulation
methods of less than 500 kHz whilst B and D would be reserved for applications utilizing a whole
500 kHz channel. Amateurs using digital transmission methods should are urged to ensure that their
transmissions do not spread beyond band edges.
Such usage guidelines could be incorporated into IARU Handbook and operating recommendations,
which provide amateurs with guidance on assisting compatibility with primary users in other shared
allocations to the amateur service.
The four blocks that are the basis of the scheme are illustrated in Table A1.2.
46 Rep. ITU-R M.2478-0
TABLE A1.2
Guidance for 52-54 MHz amateur applications
Block A B C D
Block centre frequency
(MHz)
52.25 52.75 53.25 53.75
Post WRC-19 further IARU band planning may be initiated to accommodate specific applications.
For example full size blocks may be needed for DATV or regional/trunk data-links, whereas other
blocks may be subdivided for local 100 kb/s simplex user access. A particular benefit of VHF for this
is that amateurs can achieve non-line of site data communications, which is not possible in
UHF/Microwave bands with conventional Wi-Fi, etc.
The scheme is also adaptable for countries where parts of the 52-54 MHz range may have existing
assignments to other services and will facilitate sharing.
New applications include:
– Reduced Bandwidth Digital Amateur Television (RB-DATV) could be implemented above
52 MHz. Current trials have shown that with leading-edge amateur innovation the lowest
data rate achievable for RB-DATV (MPEG-4/DVB-S QPSK) is 333 kb/s requiring a
necessary bandwidth of 500 kHz. See examples from the Radio Society of Great Britain; the
British Amateur Television Club and proceedings of the June 2017 UK Ofcom BRIG for
further details of this experimental work.
– IP links/mesh networks and innovative compressed multimedia transmission systems
(currently based on DVB-S2/MPEG technologies adapted for terrestrial use).
– Adaptations of HAMNET terminal devices. HAMNET is a mainly IP based broadband point-
to-point network in the amateur service utilising spectrum mainly in allocations to the
amateur service at 2.3 GHz and 5.7 GHz. There are already today a high number of users of
the HAMNET applications in those countries where it is in use.
– Amateur innovation in the 52-54 MHz frequency band could also pioneer the way for
commercial applications in other parts of the low VHF band where many administrations are
investigating how such spectrum might be used in an efficient and effective manner. HoT
(HAMNET of Things) and Station to Remote Station are anticipated applications.
Many of the applications mentioned above currently exist in amateur service microwave bands and a
few Region 1 countries with experimental amateur VHF development spectrum. Their further
development and adaptation to the frequency band 50-54 MHz requires the certainty of a sufficiently
wide frequency allocation in Region 1. Digital communications is a highly innovative area and it is
likely that additional applications will subsequently emerge. In Region 1 the sub-band 52-54 MHz is
currently band planned by IARU as appropriate for ‘all-modes’ in those countries where it is already
allocated (RR No. 5.169). Consistent with this current position is the service categories designated
for amateur applications used in this document.
The availability of 52-54 MHz would additionally encourage development of new technologies to
support disaster relief in accordance with the IARU-ITU and Red Cross/Red Crescent Memorandum
of Understandings4 on disaster relief operations, consistent with Article 25.9A of the Radio Regulations.
Examples applications would be mobile video used for searching for survivors in earthquakes and easier
establishment of medium capacity digital links over difficult propagation paths.
4 Copies of the MoUs are at: http://www.iaru.org/uploads/1/3/0/7/13073366/ituandiarumou.pdf
and http://www.iaru.org/uploads/1/3/0/7/13073366/ifrcandiarumou.pdf.
Rep. ITU-R M.2478-0 47
50 MHz amateur digital systems will thus either evolve from existing developments in other
VHF/UHF bands, or will incorporate the use of new technologies and applications that will benefit
from the physical characteristics of the frequency band in question.
A1.11 Power flux density
On the understanding that a land mobile application in the band 52-54 MHz would in general utilise a
25 kHz channel (16 kHz {42 dBHz}receiver bandwidth as per Tables 3 and 9). A 17 dBW e.r.p. amateur
emission in a 500 kHz (57 dBHz) channel would produce a power density of –40 dBW/Hz. In a receiver
having a bandwidth of 16 kHz this would equate to an amateur emission of 2 dBW e.r.p. See Tables 3
and 9. This also assumes that the power from an amateur emission is spread evenly across the channel
in use by the victim’s receiver. In any agreement covering this band a spectral density could be specified
to adequately protect governmental systems. In any event amateurs shall always use the minimal power
necessary to establish a reliable link. Typically this can be affected by modem software estimating the
possible power reduction achievable knowing the actual signal to noise ratio.
A1.12 Station identification by call-sign
Mitigation measures are addressed in section 9 of this Report. It is likely that systems transmitting in
the 52-54 MHz frequency band will be software based using SDR techniques with digital modems.
As for any amateur transmission a valid call-sign should be emitted at agreed/specified intervals. A
beacon could also be broadcasted at agreed intervals enabling governmental stations to take
appropriate action prior to harmful interference occurring. This would facilitate the identification of
amateur stations which may be causing harmful interference. In addition an electronic or manual log
of transmissions could be required.
A1.13 Listen before talk (transmit)
Another mitigation measure (see also § 9 of this Report) is listen before talk. Amateur stations using
52-54 MHz would in general be operating on a secondary basis. Active transmitting stations should
be required to implement a “listen before talk or transmit” scheme and be in a position to detect the
use of spectrum by governmental users before commencing their transmissions.
Recommendation ITU-R M.1825 gives guidance on how to perform sharing studies related to systems
in the land mobile service. It establishes a list of parameters, that characterize a system to assist in
sharing studies, provides information on the methodologies that can be used for sharing analyses
involving the land mobile service and describes mitigation techniques that can improve spectrum
sharing. It also contains a list of relevant ITU-R Recommendations, Reports and Handbooks.
Listen before talk is a classic mitigation method since if a frequency is already occupied by an
authorized service there is no point for another potential user to start transmitting especially if both
potential users have been assigned alternative frequencies. In particular the following concepts can
be implemented:
Dynamic channel selection techniques – The radio system can potentially use one of a number of
channels within a band for each transmission. The radio system listens on all of those channels to
determine which ones are occupied and dynamically chooses the channel to be used accordingly.
Such techniques include for example Dynamic Frequency Selection, or Detect and Avoid
mechanisms (SPEC).
Static channel selection techniques – Before transmitting, the radio system listens on predetermined
sub-channel(s) to determine whether a channel is appropriate for transmission. Such techniques
include, for example, listen before talk or other static detect and avoid mechanisms (SPEC).
48 Rep. ITU-R M.2478-0
A1.14 Band Availability
Before transmitting in the band amateur stations should be required to check that the band is open
and available to the amateur service in their country. Information should be provided on
administrations’ web-pages and on web-pages of amateur societies recognized by the local
administration.
Annex 2
Statistics – number of amateur stations and density
Using 2016 data collected from various sources, the number of amateur stations per square kilometre
has been calculated for most CEPT countries in Table A2.1. This data may be further refined to
develop user densities in urban and rural areas.
TABLE A2.1
CEPT Amateur statistics for May 2019
Country Licensees Licensees
per km2
Albania 117 0.0041
Andorra 82 0.1752
Austria 6 467 0.0771
Belarus 1 400 0.0067
Belgium 5 261 0.1723
Bosnia and Herzegovina 3 500 0.0684
Bulgaria 6 960 0.0627
Croatia 1 657 0.0293
Cyprus 236 0.0255
Czech Republic 5 396 0.0684
Denmark 8 680 0.2022
Estonia 600 0.0132
Finland 7 229 0.0214
France 13 752 0.0214
Germany 74 698 0.2092
Greece 6 900 0.0523
Hungary 3 120 0.0335
Ireland 1 801 0.0256
Italy 25 000 0.0830
Latvia 340 0.0053
Lithuania 730 0.0112
Luxembourg 559 0.2162
Rep. ITU-R M.2478-0 49
TABLE A2.1 (end)
Country Licensees Licensees
per km2
Malta 439 1.3892
Monaco 51 25.2475
Netherlands 12 637 0.3042
Norway 6 745 0.0208
Poland 13 098 0.0419
Portugal 5 677 0.0616
Romania 4 048 0.0170
San Marino 100 1.6393
Slovakia 1 500 0.0306
Slovenia 4 400 0.2171
Spain 30 756 0.0609
Sweden 13 000 0.0289
Switzerland 4 818 0.1167
The Russian Federation 37 500 0.0021
Ukraine 11 460 0.019
United Kingdom 84 694 0.3477
With the very high and very low values of countries such as Albania, Belarus, Latvia, Malta, Monaco
and San Marino removed from the calculation, the average population density of amateur operators is
0.073 licensees/km2. Statistics for the Russian Federation and Ukraine are included for completeness
and were not used in the calculations as the data was provided after the calculations were finalised.
Annex 3
An application-based approach to calculation of spectrum needs
This Annex describes an application based approach calculation of the amateur spectrum need, within
the band 50-54 MHz. This approach can:
– take account of the expected capabilities and usage scenarios, and
– be readily implemented using common software tools such as a spreadsheet.
The results from this calculation procedure need to be considered carefully given that the output might
be sensitive to the input parameter values on the usage of advanced applications which can be drawn
from a large range of possible values. This input parameter, on the other hand, could reflect the
different situation in particular regions or countries.
50 Rep. ITU-R M.2478-0
A3.1 Principles for calculating spectrum needs
This paragraph describes spectrum needs calculation principles relating to half-duplex applications
and beacons, with clarification of terminology to reflect amateur usage and to set minimum
operational conditions. In this case an application is considered to be equivalent to a transmission
mode e.g. CW, SSB, FM etc. The characteristics of Amateur Service stations used in spectrum needs
calculations are contained in Table 9 of this Report.
NOTE – Repeaters and gateways are treated the same as the other applications except that the session duration
is taken as 8 760 hours as the systems are required to operate at any time.
A3.2 Geographic Parameters
Cell geometry and usage density:
– D_A: Density of amateur radio users / km2.
– Cell area (coverage area; a function of application, antenna height, TX power, S/N_min).
This is assumed to a circular area of radius X km which is estimated to be the distance over
which a contact may be made at an acceptable signal to noise ratio. Distance X is primarily
dependent on application and is based on actual experience.
A3.3 Traffic Parameters
The following frequency bands are generally available to the amateur service in CEPT countries,
subject to local licensing conditions and are often incorporated into commercially available
transceivers:
TABLE A3.1
Principal frequency bands used by the Amateur Service in Region 1
Frequency band Designator
1 1,800-2,000 kHz 160
2 3,500-3,800 kHz 80
3 5,351.5-5,366.5 kHz 60
4 7,000-7,200 kHz 40
5 10.100-10.150 MHz 30
6 14.000-14.350 MHz 20
7 18.068-18.168 MHz 17
8 21.000-21.450 MHz 15
9 24.890-24.990 MHz 12
10 28.000-29.700 MHz 10
11 50.000-52.000 MHz 6
12 144.000-146.000 MHz 2
– R_A_50_54: Based on experience, a simple estimation of the fraction of amateurs using the
band 50– 54 MHz has been made based on an equal spread of amateur licensees across the
12 most popular currently available amateur service frequency allocations e.g. 8.3% per band.
This has been rounded to 0.08. The estimation is based on the long term (1 year) usage
patterns as actual usage of the band at any given time will be highly variable.
Rep. ITU-R M.2478-0 51
– R_App: An estimation of the fraction of amateurs using one of the specified applications in
the band 50–54 MHz. The estimation is based on the long term (1 year) usage patterns as an
application’s actual usage at any given time will be highly variable.
– T_session: Session duration. Taken to be the time in hours per day (averaged over 1 year) a
station is active using a given application, either receiving or transmitting.
– W: Observation window. Taken to be 1 year = 8 760 hours.
– F_activity: Activity factor. Fraction of T_Session when transmitter is active, assumed to be
0.5 for typical Press-To-Talk usage. Assumed to be 1 for beacons which are always
transmitting.
A3.4 Technology
To accommodate a mix of analogue and digital applications all calculations are based on a simple
channel bandwidth. However many transmission modes are not compatible with each other and
cannot share spectrum, therefore a summation of spectrum is required for each individual application.
Additionally, the calculated spectrum for each application is rounded up to the next integer multiple
of the application channel bandwidth as a fractional bandwidth would not allow the application to
function correctly.
A3.5 Calculations
1 Calculate the average number of amateurs or transmitters per km2 at any time in the year
using the spectrum in the frequency band 50–54 MHz for a specific application:
Nb_Amateurs_km2_Application = D_A * R_A_50_54 * R_App
2 Calculate the number of amateurs within one cell using a specific application within the band
50–54 MHz:
Nb_Amateurs_Cell = Nb_Amateurs_km2_Application * cell_area
3 Calculate the spectrum within a cell for a specific application:
BW_app = Nb_Amateurs_Cell * Channel bandwidth
4 Calculate the bandwidth for the specific application over the operating session time. This is
required spectrum averaged over time and the result may be less than the specified channel
bandwidth for the application:
Occup_BW_app = BW_app * F_activity * T_session / W
5 A test is necessary:
If Occup_BW_app < application channel bandwidth then:
i) Occup_BW_app = application channel bandwidth
ii) Else Occup_BW_app = Round up to next integer multiple of channel bandwidths e.g. 1.5
-> 2
6 Calculate the total required spectrum within the band 50 – 54 MHz:
Occup_BW = Occup_BW_app1 + Occup_BW_app2 +… Occup_BW_app_n
A3.6 Results of application-based approach
Results show that, based on the average amateur density in the CEPT area, the required spectrum
exceeds 4 MHz and is considerably more in areas of high population density e.g. in the case of
Germany with its high amateur population density estimated spectrum requirement exceeds 10 MHz.
52 Rep. ITU-R M.2478-0
An embedded Spread Sheet reflecting the calculation method is provided below in Figure A1. This
shows that 4.162 MHz of spectrum is currently envisaged to meet the average Region 1 spectrum
requirements of the amateur service in the frequency band 50-54 MHz, whilst 10.024 MHz would be
required to meet the spectrum needs in a high density area such as Germany.
Work Sheet Spectrum Needs AI 1-1 v2.0.xlsx
Annex 4
Another analysis of amateur band occupancy
A significant number of frequency bands are allocated to the Amateur Service in accordance with
Article 5 of the ITU Radio Regulations. In this regard there are specifications of their use.
Region 1
1 810–1 850 kHz
AMATEUR
5.98 5.99 5.100
1 850–2 000 kHz
FIXED
MOBILE, except aeronautical mobile
5.92 5.96 5.103
The 1.8 MHz band (the 160-metre band) was earlier used by beginners for short-range voice-mode
communications (AM and LSB) or by experienced radio amateurs for Morse Code communications.
At present, communications are mainly carried in a narrow range of the telegraph band and around
1 900 kHz in the telephone band. Sometimes ‘round-table’ sessions are held in the 1 900-1 920 kHz
frequency band. This band’s occupancy is very low. Usually this band is not used during
competitions.
Region 1
18 068–18 168 kHz
AMATEUR, AMATEUR-SATELLITE
5.154
The 18 MHz band (the 17-metre band). This band is used for operation of all types of emissions.
Major propagation takes place during daytime and evenings. Many free ranges can be observed during
listening. This band is not used during competitions.
Region 1
21 000-21 450 kHz
AMATEUR, AMATEUR-SATELLITE
Rep. ITU-R M.2478-0 53
The 21 MHz band (the 15-metre band). This is one of the principal bands for DX communications
and competitions. Major propagation takes place at morning time. It is actively used when
propagation is sufficient however its occupancy is not very high.
Region 1
24 890–24 990 kHz
AMATEUR, AMATEUR-SATELLITE
The 24 MHz band (the 12-metre band). This band is used for operation of all types of emissions.
Propagation in this band is currently poor, but in principle DX communications are possible. Many
free ranges can be observed during listening. This band is not used during competitions.
Region 1
28–29.7 MHz
AMATEUR, AMATEUR-SATELLITE
The 28 MHz band (the 10-metre band). In this band propagation strongly depends on solar conditions.
In the past it was used for voice-mode communications (USB, FM) by beginners as well as
experienced radio amateurs. At present propagation bursts are extremely rare and many free ranges
can be observed during listening.
Regions 2 and 3
50-54 MHz
AMATEUR
As per Article 5 of the Radio Regulations, in Regions 2 and 3 the frequency band 50-54 MHz is
allocated to the amateur service on a primary basis.
As per the European ECA table, the frequency band 50-52 MHz is allocated to the amateur service
on a secondary basis and is used in almost all European countries by amateur service stations in
accordance with Article 4.4 of the Radio Regulations.
At the same time, according to the website dxwatch.com, which records the conduct of amateur radio
communications, including communications by radio amateurs in Regions 2 and 3, the actual
occupancy of the subject band is quite low. Table A4.1 shows the number of amateur radio
communications conducted in the 50-54 MHz band (wavelength 6 m), between 12.05.2018 and
14.05.2018.
As seen from the sample provided, operations are mainly conducted in one radio frequency,
50.313 MHz, and more rarely, in the band 50.090-50.260 MHz. The numbers of amateur radio
communications conducted in the 50-54 MHz band at other time periods are not significantly different
from those shown in Table 9.
54 Rep. ITU-R M.2478-0
TABLE A4.1
Amateur radio communications conducted in the band of
frequencies 50-54 MHz, according to the website dxwatch.com
Receiver station Transmitter station Frequency,
kHz
Session date
IK5GQK (Italy) CT2HPM (Portugal) 50313 1349z 14 May
IK5GQK (Italy) CT1ANO (Portugal) 50313 1346z 14 May
AC2PB (USA) AE7KI (USA) 50313 1337z 14 May
AC2PB (USA) W8OI (USA) 50313 1330z 14 May
IK6DTB (Italy) 4U1ITU (ITU) 50096 1326z 14 May
HA8VA (Hungary) HA8QRP (Hungary) 50091 1319z 14 May
EA5CI (Spain) 4U1ITU (ITU) 50096 1316z 14 May
4U1ITU (ITU) 4U1ITU (ITU) 50096 1314z 14 May
KK4XO (USA) AC2PB (USA) 50313 1256z 14 May
KK4XO (USA) KD9VV (USA) 50313 1255z 14 May
DK5EW (Germany) OY9JD (Denmark, Faroe
Islands)
50130 1255z 14 May
PC4N (Netherlands) PE1RF (Netherlands) 50314 1251z 14 May
M0CGL (UK) OY9JD (Denmark, Faroe
Islands)
50130 1251z 14 May
VE1SKY (Canada) VE1PZ (Canada) 50313 1247z 14 May
DF4PL (Germany) LX0SIX (Luxembourg) 50022 1246z 14 May
KT4FW (USA) NF3R (USA) 50313 1235z 14 May
VE1SKY (Canada) K8LEE (USA) 50313 1234z 14 May
DK5EW (Germany) GS3PYE (UK) 50313 1231z 14 May
VO1VCE (Canada) VO1FU/B (from China) 50073 1229z 14 May
F1YJ (France) OY9JD (Denmark, Faroe
Islands)
50130 1228z 14 May
GM4FDM (UK) OY9JD (Denmark, Faroe
Islands)
50130 1227z 14 May
M0TLI (UK) OY9JD (Denmark, Faroe
Islands)
50130 1223z 14 May
K1TOL (USA) EUVIDEO (Belarus) 50000 1221z 14 May
EI7HBB (Ireland) DF3XZ (Germany) 50099 1220z 14 May
VE1SKY (Canada) K1TOL (USA) 50313 1219z 14 May
VE1SKY (Canada) WA2GSX (USA) 50313 1219z 14 May
F4AZF (France) OY9JD (Denmark, Faroe
Islands)
50130 1218z 14 May
VE1SKY (Canada) N3RG (USA) 50313 1218z 14 May
PA1MR
(Netherlands)
OY9JD (Denmark, Faroe
Islands)
50130 1216z 14 May
LA4LN (Norway) EI4DQ (Ireland) 50313 1215z 14 May
Rep. ITU-R M.2478-0 55
TABLE A4.1 (end)
Receiver station Transmitter station Frequency,
kHz
Session date
PC2J (Netherlands) OY9JD (Denmark, Faroe
Islands)
50130 1210z 14 May
UN7TW
(Kazakhstan)
JE1BMJ (Japan) 50313 0558z 14 May
VU2NKS (India) VU2NKS (India) 50313 0542z 14 May
K7XC (USA) K7XC (USA) 50260 1744z 13 May
4Z4DP (Israel) 4Z70IARC (Israel) 50099.8 1616z 13 May
LZ3BS (Bulgaria) 5B4AIF(Cyprus) 50314 1014z 13 May
SV1QFF (Greece) F6HLC (France) 50133.2 0829z 13 May
HA1VG (Hungary) G2KF (England) 50140 0759z 13 May
HA1VG (Hungary) G2KF (England) 50140 0753z 13 May
HA1VG (Hungary) G7RAV (England) 50092 0752z 13 May
2E0XXO (UK) IW1JTQ (Italy) 50170 0729z 13 May
W9BWR (USA) AA0MZ (USA) 50313 1747z 12 May
4Z4DP (Israel) IW9GDC/B (Italy) 50006 1727z 12 May
4Z4DP (Israel) SV1SIX (Greece) 50040.1 1723z 12 May
SV9CVY (Greece) K1TOL (USA) 50313 1518z 12 May
SV9CVY (Greece) K1TOL (USA) 50313 1458z 12 May
WB4JPG (USA) W1AIN (USA) 50125 1434z 12 May
PU5BOY (Brazil) PU5BOY(Brazil) 50160 1344z 12 May
SV9CVY (Greece) BD0AAI (China) 50313 1337z 12 May
F1OOG (France) EA9ACD (Spain) 50160 1012z 12 Maу
Analysis of the occupancy of the frequency bands allocated to the Amateur Service shows that
frequency bands allocated to the Amateur Service are not over-occupied at present and for that reason
it is possible to meet the spectrum needs of the Amateur Service within the existing allocations.
Therefore additional spectrum allocation to the Amateur Service in the 50-54 MHz band is not
required.
Annex 5
Amateur service sharing with (analogue television) broadcasting service
A5.1 Introduction
WRC-19 agenda item 1.1 is to consider an allocation of the frequency band 50-54 MHz to the amateur
service in Region 1, in accordance with Resolution 658 (WRC-15). The Resolution requests, to take
into account the results of sharing studies with incumbent services. Section 8.2 and this annex deal
with the compatibility between the amateur service and the broadcasting service prior to any switch-
56 Rep. ITU-R M.2478-0
off of the analogue broadcasting service in this frequency band. Section 8.3 of this Report provide
the results of the study.
Various mechanisms were studied which have been used by administrations in Regions 1 and 3 to
regulate the amateur service in the 50-54 MHz frequency band where amateur stations have existed
in relatively close geographical proximity to the service areas of analogue television broadcasting
stations. In addition, ITU-R WP 6A has provided WP 5A with details of the current ITU-R
Recommendations which detail the criteria necessary to assess sharing conditions and these have been
used in formulating the sharing model detailed in § A5.2 below. To address part of the sharing
scenario requested by WRC-19 agenda item 1.1, § A5.2 of this Annex details a sharing model that
can be used or adapted to demonstrate how sharing between the amateur service and the remaining
analogue television broadcasting applications in Region 1 in the band 50-54 MHz is feasible.
Section A5.6 provides details of the scenario used for analyzing the sharing situation between the
amateur service and analogue television in the broadcasting service in the Russian Federation. The
sharing method calculates the difference in field strength between the wanted TV field and the field
resulting from an amateur transmitter.
Recommendation ITU-R SM.851-1 has been used in many forums to address sharing between the
amateur service and the broadcasting service. In general this appears acceptable in the case of
avoiding harmful interference to analogue broadcasting; however care must be exercised when
addressing the polarization of amateur stations’ antennas which may be vertically or horizontally
polarized depending on the location and application being utilized.
The minimum median value of the field strength to be protected is specified as 46 dB µV/m in Table
1 of Recommendation ITU-R SM.851-1 (50% of time, 90% of locations). The required protection
ratio is also given by Recommendation ITU-R SM.851-1, which is determined from Tables 3, 5 and
Fig. 2 of the Recommendation and depends on the frequency separation between wanted and
interfering emissions.
The amateur signal strength is calculated using ITU-R recommendations and assumes the use of a
four element Yagi antenna with the characteristics shown in the Fig. A5.1 below. The signal strength
is further adjusted based on factors to adjust for differences in signal polarization, receiver antenna
gain factors and losses due to obstructions between the amateur station and TV receiver.
A5.2 Method
The minimum field strength for which protection against interference is provided in planning should
never be lower than 46 dBµV/m (Table 1 of Recommendation ITU-R SM.851-1).
Remaining analogue television transmitters in Region 1 generally utilise the SECAM System D/K
standard with a channel centre frequency of 52.50 MHz, vision carrier frequency 49.75 MHz and
sound carrier 56.25 MHz. Carrier offsets may be used.
The method involves calculating the difference between the wanted TV signal's field and the field
resulting from an amateur transmitter operating on a frequency within the TV channel some distance
away from the edge of the TV service area. If the amateur signal is less than the minimum signal
strength based on the minimum required TV signal field strength adjusted for the protection ratio,
then no harmful interference will occur.
Due to propagation phenomena it is estimated that European amateur stations such as those described
in the paragraph below, which establishes the field strength from a specific type of amateur station
less than 500 kHz from the 49.75 MHz video carrier of a television station will be transmitting for
only 8.5% of daylight hours on 90 days within a year. In other parts of Region 1 especially in
geographical areas nearer to the equator activity times may be greater.
Rep. ITU-R M.2478-0 57
Other amateur applications including digital emissions with channel bandwidths of up to 500 kHz
will employ a lower station e.r.p. generally not exceeding 20 dBW and will be separated from the
49.75 MHz vision carrier by between 1 and 4 MHz, thus requiring a lower protection ratio to protect
the service area of the television broadcasting transmitter. Conversely the amateur emissions’ duty cycle
is likely to be greater than the higher power amateur transmitters closer to the vision carrier.
FIGURE A5.1
Polar Diagram of assumed amateur transmitting antenna
A5.3 Variables for the unwanted amateur station signal
E is the field strength (dB µV/m) of a typical amateur station which is located at a distance of d km
from the service area of an analogue television transmitter. It assumes the amateur station antenna is
pointing in the direction of the TV station and uses a state-of-the-art four element Yagi antenna design
as shown in the figure above. The maximum gain is approximately 9 dBi which equates to 7 dBd.
The value of E is determined using Recommendation ITU-R P.1546 curves for land paths for the case
of 10% time and 50% locations, and h2 = 10 m and e.r.p. of 30 dBW. Pr is the radio frequency
protection ratio. This value is determined from Recommendation ITU-R SM.851-1. For the situation
given above with a carrier separation of around 400 kHz a Pr of 50 dB is required.
58 Rep. ITU-R M.2478-0
At is the amateur transmitting antenna factor. From the antenna diagram above, the side-lobe gain is
–18 dBi which equates to –20 dBd. It is extremely likely that amateur operators will point their
antennas away from the broadcasting transmitters which are geographically close to them because:
– TV video signal levels in their receivers will be excessive and would interfere with the
reception of weak signals and most importantly,
– Administrations which have a large number of analogue television transmitters remaining in
their territory have generally not authorized amateur emissions from their territory in the 50-
54 MHz frequency band. Since amateur operators outside such jurisdictions do not have the
possibility of making amateur communications with such geographical areas it is unlikely
that they will beam their emissions towards such territories.
Ol is the Obstruction loss. Amateur radio stations are generally situated in domestic locations. They
are not normally located on prime VHF sites and are often in heavily obstructed areas. Obtaining any
degree of foreground Fresnel zone clearance is in many cases impossible. For the purposes of this
study a 10 dB obstruction loss for amateur stations has been assumed at these frequencies.
Cp is a receiving antenna polarization factor. Recommendation ITU-R P.1406 indicates that
polarization changes due to scattering from various obstacles may be significant and that such
scattering increases as the frequency is lowered reaching a maximum or about 18 dB at 35 MHz. As
the standard deviation of the scattering is significant, a value of 10 dB is assumed for the cross
polarization loss at 50 MHz for the purposes of this study.
Ad is a television antenna receiving discrimination factor determined from Recommendation ITU-R
BT.419 entitled Directivity and polarization discrimination of antennas in the reception of television
broadcasting. Television receiving antennas nearest to amateur stations are likely to be pointed away
from amateur stations whereas there will be additional geographical separation between television
receiving antennas pointing towards the broadcasting transmitter and amateur stations in the model.
7 dB is permitted for this situation.
Afs, the aggregate field strength of the amateur stations at a given distance from the edge of the TV
station service area, is calculated from:
Afs = E + At + Ol + Cp + Ad
A5.4 Variables for the wanted TV signal
Tfs is the minimum TV Field strength of 46 dBµV/m.
Pr is the required protection ratio, specified by the relevant ITU-R Recommendations depending on
the type of TV service and the frequency separation between the wanted and unwanted signal.
TVifs is the maximum field strength of the interfering signal calculated from the minimum wanted
TV signal field strength adjusted by the specified protection ratio:
TVifs = Tfs – Pr
A5.5 The calculation
The difference in field strength is calculated between the wanted TV field with its protection factor
(TVifs) and the field resulting from an amateur transmitter (Afs).
If the amateur station(s) field strength (Afs) is equal to or less than the TV interference field strength
(TVifs), then there should be no interference. If the Afs is greater than TVifs, interference is possible.
E.g. for no interference:
TVifs ≥ Afs
Rep. ITU-R M.2478-0 59
which is calculated from:
Tfs – Pr ≥ E + At + Ol+ Cp + Ad
where all the variables are in dB.
A5.6 Sharing scenario
This section addresses the results of calculations concerning sharing between the amateur service in
neighbouring Region 1 countries adjacent to the Russian Federation and legacy analogue television
transmitters utilising SECAM System D/K with a channel centre frequency of 52.50 MHz, vision
carrier frequency 49.75 MHz and sound carrier 56.25 MHz. Carrier offsets may be used.
TABLE A5.1
System D 625 lines
Channel Video-carrier
(MHz)
Centre
(MHz)
Colour-subcarrier
(MHz)
Audio-carrier
(MHz)
2 49.75 52.50 54.18 56.25
3 59.25 62.00 63.68 65.75
It should be noted that the video carrier is outside the band being considered for an allocation to the
amateur service in Region 1, the separation between the amateur transmitter and the vision carrier
being greater than 400 kHz.
Pr = 50 dB. This value was determined from Tables 3 and 5, and Fig. 2 of Recommendation ITU-R
SM.851-1 based on video carrier protection.
For a 50 km distance and one transmitting amateur station, the calculated figures for this sharing
scenario are given below.
TABLE A5.2
Component Values
E: Amateur signal level dB(µV/m) from stations 50 km from
TV service area boundary
27
At: TX side-lobe gain (dBd) -20
Ol: obstruction loss (dB) -10
Cp: Antenna polarisation factor (dB) -10
Ad: TV RX antenna discrimination factor (dB) -7
Amateur field strength at edge of TV service area dB(µV/m)
Afs = E + At + Ol + Cp + Ad
-20
Tfs: Wanted TV signal strength at service area boundary
dB(µV/m)
46
Pr: Interference protection ratio (dB) 50
Permissible interference field strength at TV service area
boundary: TVifs = Et – Pr
-4
TVifs > or = Afs? Yes
Interference from amateur stations? No
60 Rep. ITU-R M.2478-0
A5.7 An alternative approach
Although the sharing study described in previous paragraphs suggests that sharing would be feasible
between SECAM analogue television broadcasting and the amateur service in the frequency band
50-54 MHz a SEAMCAT study has been conducted to determine the probability of harmful
interference occurring for several sharing situations for different configurations of the broadcasting
and amateur services. Using Monte-Carlo simulators such as the CEPT/ETSI SEAMCAT software
package allow various scenarios to be examined relatively quickly. The simulations conducted are
thought to represent typical worst-case situations that might be encountered if the broadcasting
service (analogue television) coexists with the amateur service in the 50-54 MHz frequency band.
Report ITU-R SM.2028-1 is particularly relevant in this regard.
Further details of the SEAMCAT analyses are contained in Annex 6 to this Report.
A5.8 Summary and conclusions
This study shows that sharing is possible using the method described without any harmful interference
occurring from an amateur transmitter with a power level (e.r.p. of 30 dBW) at a distance of 50 km
from a television transmitters’ service area in the frequency band 50-54 MHz.
This study details a method of ascertaining whether a rather basic sharing scenario will likely protect
remaining analogue television broadcasting applications in Region 1 in the band 50-54 MHz, until
this band is no longer used for broadcasting.
The method calculates the difference in field strength between the wanted TV field with its protection
factor (TVifs) and the field resulting from an amateur transmitter (Afs).
If the amateur station(s) field strength (Afs) is equal to or less than the TV interference field strength
(TVifs), then there should be no interference. If the Afs is greater than TVifs, interference is possible.
In addition to the method described in §§ A5.1 to A5.5, a Monte-Carlo SEAMCAT simulation was
conducted and discussed in § 8.4 and the results are contained in § 8.5 and Annex 6 to this Report.
The predicted probability of interference between the amateur service and the TV broadcasting
service is relatively low if typical operating conditions of both the TV service and amateur service
are taken into account. In both rural and suburban environments the calculated mean signal strength
(dRSS) of the TV signal is greater than the minimum receiver sensitivity of -48 dBm implying that
the TV receivers display relatively interference free images when the amateur stations are not
transmitting.
Notwithstanding that the interference probability is low; any harmful interference which does occur
could likely be handled through bilateral or multilateral agreements in place with neighbouring
countries.
It is believed that the foregoing has described scenarios to demonstrate that successful sharing is
possible between the amateur service and broadcasting service in Region 1, in European countries
which border those countries which have NOT so far implemented a full changeover to terrestrial
digital television broadcasting in bands above 174 MHz.
Rep. ITU-R M.2478-0 61
Annex 6
A Monte-Carlo simulation study of compatibility between
the analogue TV broadcast service and the amateur service
A6.1 Introduction and summary
This Report presents the results of Monte-Carlo simulations using the SEAMCAT software tool to
predict the probability of interference to residential analogue TV reception in suburban and rural
environments by stations of the amateur service.
The probability of interference is found to be low in the cases considered by this study.
A6.2 Study details
This study considers two typical scenarios:
– A major metropolitan area with a high powered TV broadcast transmitter.
– A small rural township serviced by a relatively lower power transmitter.
Two propagation models were used in the simulations, with the most appropriate model selected for
each service:
– For the TV broadcasting service ‘ITU-R P.1546-4 Land’ with the analogue broadcasting
option selected and signal strength calculations are for between 10% and 50% of the time.
ITU-R P.1546 calculations are only valid for field strengths exceeded for percentage times
in the range from 1% to 50%.
– For the amateur service the ‘Extended-Hata’ model was used.
For the TV receiver, the required protection ratio of wanted to unwanted signal strengths (C/I) is
54 dB. The sensitivity of the TV receiver is –48 dBm (~1 mV into 50 Ohms) and the bandwidth of
the TV signal is assumed to be 5 MHz.
The TV receiving antenna used in the study is a low gain design which is ‘built in’ to SEAMCAT
and it would be suitable for short to medium range reception of TV signals; however it is likely, and
experience suggests, that receivers on the outskirts of the TV coverage area will use antennas with
higher gains and more directional characteristics which will reduce the potential for interference from
any directions other than the main lobe that will be pointing towards the TV broadcast transmitter
antenna.
The study assumes two amateur stations operating anywhere within a 50 km radius of the TV
broadcast transmitter. The two amateur stations have a 100 W transmitter and use four-element Yagi
antennas at 10 m elevation and are operating on a 5% duty cycle. The amateur transmitters may be
communicating to receivers either inside or outside of the TV service area. All the parameters used
by SEAMCAT are given in Table A6.3.
A6.3 The major metropolitan area study
This study is modelled on the TV transmitter in Moscow found in the ITU BR database record
061000305, an extract of which is shown in Fig. A6.3.
The TV broadcast transmitter is assumed to have an effective radiated power of 316 kW (85 dBm)
into an omni-directional antenna with a numerical gain of 1 at an effective height of 385 metres and
the radius of the TV service area is assumed to be 50 km. The predictions for the probability of
interference made by SEAMCAT for the metropolitan area are shown in Table A6.1 and the
simulation outline is shown in Fig. A6.1.
62 Rep. ITU-R M.2478-0
TABLE A6.1
Probability of interference for the major city calculated by SEAMCAT using the parameters
given in Table A6.3. The C/I column is the calculated percentage of interference for the C/I
protection criteria of 54 dB; Mean dRSS is the calculated mean signal strength of the desired
TV signal and its standard deviation also shown
C/I %
(54 dB)
Mean dRSS
(dBm)
dRSS StdDev
(dBm) Environment
0.14 -29.69 11.34 Suburban
0.81 -29.09 11.27 Rural
FIGURE A6.1
Simulation outline of the major metropolitan area (Moscow) study. This figure shows 601 positions of the 100 000 random
positions that SEAMCAT simulates to predict the probability of interference
A6.4 The rural centre study
This study is modelled on the TV transmitter in Zapadnaya Dvina Tver found in the ITU BR database
record 096002674, an extract of which is shown in Figure A6.4. The other parameters used in the
simulation, e.g. receiver antenna, sensitivity, amateur characteristics, etc., are the same as previously
described in § A6.2 above.
Rep. ITU-R M.2478-0 63
The TV broadcast transmitter is assumed to have an effective radiated power of 165 W (52.2 dBm)
into an omni-directional antenna with a numerical gain of 1 at an effective height of 92 metres and
the radius of the TV service area is assumed to be 5 km.
Given the low transmitter power of 165 Watts (22.2 dBW) and relatively low antenna height (92 m),
it is assumed that the broadcast station serves a small rural community or some other type of isolated
compact settlement. The image from Google Earth (Figure A6.8) shows the town at the center of a
largely forested area with a diameter of approximately 5 km.
Table A6.2 shows the calculated probability of interference to residential TV reception by amateur
operators and Fig. A6.2 shows the simulation outline.
TABLE A6.2
Probability of interference for the rural township calculated by SEAMCAT using the
parameters given in Table A6.3. The C/I column is the calculated probability of interference;
Mean dRSS is the calculated mean signal strength of the desired TV signal and its standard
deviation also shown
C/I %
(54 dB)
Mean dRSS
(dBm)
dRSS StdDev
(dBm) Environment
1.57 -41.06 9.99 Rural
FIGURE A6.2
Simulation outline of the rural township (Zapadnaya Dvina Tver) study. This Figure shows 601 positions of the 100 000
random positions that SEAMCAT simulates to predict the probability of interference
64 Rep. ITU-R M.2478-0
FIGURE A6.3
Extract from ITU database giving details of the Moscow television transmitter used
in the simulation in section A6.3 of this Report
FIGURE A6.4
Extract from ITU database giving details of the Zapadnaya Dvina Tver television transmitter used in the simulation in
section A6.4 of this Report
Rep. ITU-R M.2478-0 65
TABLE A6.3
The main parameters used for the SEAMCAT studies given in this document. Any other
parameters not specified were left as the program default values. SEAMCAT version 4.1.0
revision 2337 was used for this study.
Parameter Value Comments
Frequency 52.5 MHz Same frequency is used for both the TV
transmitter and amateur station
Amateur transmitter power SSB: 50 dBm (100 W) PEP Typical of amateur equipment used
around 52 MHz. See Fig. A2.2.7 for
emission mask.
Duty cycle of amateur
transmitter
SSB: 2.5% at 40 dBm and 2.5%
at 50 dBm
5% operation is 1.2 hours per day; most
amateurs would transmit less than this on
average. Considering SSB; for smoothly
read text, the mean power of the speech
signal is 10 dB lower than the power of a
reference sinusoidal signal (see Rec.
ITU-R SM.326, Note 2 to Table 1).
Amateur links antennas,
RX & TX
SSB: 4 element Yagi, 9.4 dBi
gain
Typical amateur antennas. See Fig.
A2.2.5 for radiation pattern.
Amateur antenna height,
RX & TX
10 m (above ground) A probable maximum amateur height due
to planning requirements.
Number of active amateur
transmitters in service area
2
Television broadcast
transmitter power
85 dBm (316 kW)
52.2 dBm (165)
The difference between e.r.p. and e.i.r.p.
is small and is ignored here. Since e.r.p.
is given antenna gain is assumed to be 0
dBi Television broadcast
transmitter antenna
Omni-directional vertical, 0 dBi
gain
Television transmitter height 385 m & 92 m
TV receiver antenna height 5 m (above ground)
TV receiver sensitivity –48 dBm (1 mV into 50 ohms)
TV receiver antenna gain 0 dBi See Fig. A6.6 for radiation pattern.
Pattern based on ITU-R BT.419 which is
a built-in SEAMCAT option.
TV signal bandwidth 5 MHz
Interference criteria C/I = 53.97 dB, C/(N+1) = 47 dB
(N+I)/N = 0.97 dB, I/N = –6 dB
Noise floor –103 dBm Based on the fundamental calculation of
noise power per Hertz (kTB), corrected
for bandwidth (5 MHz) and receiver
noise figure (4 dB):
–103 dBm = –174 dBm/Hz + 10 log(BW)
+ NF
Coverage radius 50 km TV transmitter to receiver
5 km TV transmitter to receiver
Major city
Rural town
General environment Rural and suburban
66 Rep. ITU-R M.2478-0
TABLE A6.3 (end)
Parameter Value Comments
Propagation model For amateur service: Extended-
Hata
TV service: ITU-R P.1546-4
Land
Suitable for elevated transmitters in a
cluttered, non-line-of-site environment
between 30 MHz and 3 GHz up to a
maximum range of 100 km
Broadcasting and other terrestrial
services, typically considered in cases
with high mounted transmitter antennas
e.g. above 50-60 m
FIGURE A6.5
Radiation pattern of the 4 element Yagi used in this study. Side lobes have not been included as the random assignment of
directions in the simulation covered all possibilities of direction by the main lobe
Rep. ITU-R M.2478-0 67
FIGURE A6.6
Radiation pattern of the TV receiver antenna
FIGURE A6.7
Emission mask of SSB transmission from the amateur station used in this study
68 Rep. ITU-R M.2478-0
FIGURE A6.8
A Google Earth image of Zapadnaya Dvina showing the extent of the settlement and rural nature of the surrounding
environment. The township appears to have a diameter of roughly 5 km as shown by the lines drawn on the image. This is in
accord with the assumed TV coverage area of 5 km radius
Rep. ITU-R M.2478-0 69
ANNEX 7
Amateur service stations interference to television receivers
of the broadcasting service in the band 50-54 MHz
A7.1 Introduction
As part of studies under WRC-19 agenda item 1.1, regarding electromagnetic compatibility (EMC)
between amateur service stations in the 50 MHz band and broadcasting service stations, the telecom
administration of the Russian Federation has performed EMC calculations for simulated sharing of
the band 50-54 MHz by broadcasting service and amateur service stations.
A7.2 Working Assumptions
The calculation of electromagnetic compatibility is based on the application of Recommendation
ITU-R SM.851-1 and Recommendation ITU-R P.1546.
The calculation assumptions used:
– In the frequency band 50-54 MHz, the characteristics of amateur service stations are taken
from Recommendation ITU-R M.1732-2 – Characteristics of systems operating in the
amateur and amateur satellite services for use in sharing studies mobile service stations;
– At is the factor that determines amateur service stations’ antenna selectivity. In calculations
in accordance with Recommendation ITU-R P.1546, the amateur service station antenna's
directivity is taken into account for each direction of transmission as the e.i.r.p. is re-
calculated based on the antenna pattern radiation reductions. For non-directional antennas At
is assumed to be 0 dB;
– Ol is the propagation loss resulting from the limited size of the Fresnel zone. The calculation
assumes 0 dB, since losses due to irregular terrain have already been addressed in the
calculation, and the boundary of the TV broadcasting area is not in built-up areas;
– Cp is a factor that accounts for polarization discrimination of the broadcasting service station
and amateur service station antennas;
– Here and hereinafter, TV stations’ reception area boundary locations affected by interference
from amateur service stations are determined through calculations of the area with an
interference level of 6 dBμV/m at a height of 10 metres with tropospheric interference (10%
of the time) and –4 dBμV/m for continuous interference (50% of the time).
The maximum interference is calculated by using the formula:
Еint_max = Tfs-N-At-Ol-Cp-Ad-PR
where Tfs is the minimum wanted field strength of the broadcasting service station in the frequency
band 48.5-56.5 MHz, determined in accordance with Recommendation ITU-R SM.851-1.
TABLE A7.1
Calculation of the wanted field strength of an analogue television broadcasting station
Wanted field strength, dBμV/m, on the boundary of the coverage area (in 50% of the time,
90% of the locations)
46
Wanted field strength, dBμV/m, on the boundary of the coverage area (50% of the time,
50% of the locations), in accordance with Rec. ITU-R BT.417
48
70 Rep. ITU-R M.2478-0
N is the number of amateur service stations operating simultaneously at a certain distance from the
boundary of the TV station’s coverage area. This calculation addresses only one amateur service
station operating.
Ad is the factor that accounts for the selectivity of TV receiving antennas. A signal strength loss of
7 dB is assumed, as per Recommendation ITU-R BT.419.
PR is the protection ratio for the signal of the analogue TV broadcasting station, calculated in
accordance with Recommendation ITU-R SM.851; it equals 49 dB (for the amateur service station
frequency of 50 MHz). For other amateur service station frequencies, the PR shall be adjusted by the
difference between the protection ratio for the frequency of 50 MHz and the protection ratio of the
frequency used by the amateur service station.
If the field strength produced by the amateur service station on the boundary of the TV signal
reception area exceeds the value of Eint_max, then the level of interference caused by the amateur
service station is considered unacceptable.
So, in order to detect amateur service stations’ interference into TV reception, one should identify
overlaps between the broadcasting station’s reception area and the amateur service stations’ area of
interference (for 10% of the time) exceeding the Eint_max level.
Protection ratios for standard 625-line systems are shown in Fig. A7.1 and Table A7.2.
FIGURE A7.1
Protection ratios for analogue TV broadcasting systems
625-line systems
Rep. ITU-R M.2478-0 71
TABLE A7.2
Protection ratios for analogue television broadcasting systems
Frequency difference between wanted and interfering carriers (MHz)
Luminance range PAL SECAM
MHz -1.25(1) -1.25(2) -0.5 0.0 0.5 1.0 2.0 3.0 3.6-4.8 5.7-6.0(3)
(4)
3.6-4.3(5) 5.7-6.3(3) (4)
dB 32 23 44 47 50 50 44 36 45 25 40 25
(1) H, I, K1, L television systems.
(2) B, D, G, K television systems.
(3) B, G television systems: the range is 5.3-6.0 MHz.
(4) This value is valid until the end of the channel.
(5) D/SECAM and K/SECAM: add 5 dB.
The calculation includes a scenario with the amateur service station located outside the ATV station’s
reception area.
The amateur service station parameters are shown in Table A7.3.
TABLE A7.3
Amateur service station parameters
Station
Antenna height
above ground
level
Antenna
directivity Polarization e.i.r.p.
Amateur_service_1 15 m Directional
(–6 to 12 dB) H 28 dBW
Amateur_service_2 2 m Non-directional V 17 dBW
Antenna attenuation diagram of an amateur station in the azimuth plane is shown in Fig. A7.2.
72 Rep. ITU-R M.2478-0
FIGURE A7.2
Antenna attenuation diagram of an amateur station in the azimuth plane (for a directional antenna)
Broadcasting service station parameters are shown in Table A7.4.
TABLE A7.4
Broadcasting service station parameters
Station
Antenna height
aboveground
level
Antenna directivity Polarization e.i.r.p.
Sankt
Petersburg
253 m Non-directional Horizontal 50 dBW
Ruskeala 45 m Non-directional Horizontal 10 dBW
A7.3 Calculation results
Based on the input data described, we plot the coverage areas of the broadcasting service stations and
the amateur service stations using the CHIRplusBC software, in accordance with Recommendation
ITU-R P.1546.
A simulation of interference between amateur service stations located on the border of Russian
Federation and actually operating TV stations in the Russian Federation is shown in Figs A7.3 to
A7.11. Each Figure is based on a calculation of an amateur service station’s interfering field strength.
Rep. ITU-R M.2478-0 73
The calculation includes the TV receiving antenna’s polarization isolation.
FIGURE A7.3
The area of interference from Amateur_service_1 to St. Petersburg ATV station
St. Petersburg station’s reliable reception area when the amateur service station operating;
The area of the amateur service station’s interference into TV signal reception from St.
Petersburg ATV station;
74 Rep. ITU-R M.2478-0
FIGURE A7.4
The area of interference from Amateur_service_2 to St. Petersburg ATV station
St. Petersburg station’s reliable reception area when the amateur service station operating;
The area of the amateur service station’s interference into TV signal reception from
St. Petersburg ATV station
We plot the interference areas of the amateur service stations with an interference level of 6 dBμV/m
during 10% of the time.
Rep. ITU-R M.2478-0 75
FIGURE A7.5
Amateur_Service_Station_1’s interference area
For Amateur_Service_Station_1, the interference distance in the direction of the territory of the
Russian Federation is 129 km.
St. Petersburg
Veliky Novgorod
Pskov
76 Rep. ITU-R M.2478-0
FIGURE A7.6
Amateur_Service_station_1’s area of interference to Ruskeala ATV station
Ruskeala station’s reliable reception area with the amateur service station operating;
The area of the amateur service station’s interference into TV signal reception from Ruskeala
ATV station
Rep. ITU-R M.2478-0 77
FIGURE A7.7
Amateur_service_station_2’s area of interference to Ruskeala ATV station
Ruskeala station’s reliable reception area with the Amateur service_2 station operating;
The area of the Amateur service_2 station’s interference into TV signal reception from
Ruskeala ATV station
78 Rep. ITU-R M.2478-0
FIGURE A7.8
The area of interference from both amateur service stations to Ruskeala ATV station
Ruskeala station’s reliable reception area when Amateur service stations operating;
The area of the amateur service stations’ interference into TV signal reception from Ruskeala
ATV station
The aggregate interference field strength has been calculated using the power summation method.
For evaluation of interference caused by amateur service stations to television receivers of the
broadcasting service in the band 50-54 MHz interference field strengths at test points were also
calculated. The results are shown in Table A7.5.
Rep. ITU-R M.2478-0 79
TABLE A7.5
Test
point
Distance
from Test
Point to TV
Station
Ruskeala, km
Distance
from Test
Point to
AS_1, km
Distance
from Test
Point to
AS_2, km
Field
strength
values from
TV station
Field strength
values from
AS_1 at the
test points,
dBμV/m
(1% of the
time)
Field strength
values from
AS_2 at the test
points, dBμV/m
(1% of the time)
TP1 10.07 3.02 10.82 48 54.3 36.6
TP2 9.52 9.77 5.10 48 41.9 49.1
TP3 0.36 12.76 14.29 88.2 43.2 32.6
TP4 0.28 13.37 14.85 90.7 42.4 32.0
TP5 11.51 24.42 22.52 47.8 33.0 26.4
TP6 10.25 22.63 24.54 48 31.0 25.3
Location of test points inside the TV station reception area boundary is shown in Fig. A7.9.
FIGURE A7.9
The minimum territorial isolation required to support compatibility of amateur service and
broadcasting service stations is calculated.
80 Rep. ITU-R M.2478-0
FIGURE A7.10
Amateur_Service_Station_1’s interference area
For amateur_Service_Station_1, the interference distance in the direction of the territory of the
Russian Federation is 175 km.
Rep. ITU-R M.2478-0 81
FIGURE A7.11
Amateur_Service_Station_2’s interference area
For Amateur_Service_Station_2, the interference distance in the direction of the territory of the
Russian Federation is 70 km.
A7.4 Findings and Proposals
The study results show that the amateur service stations’ field strength values at the test points exceed
the previously determined threshold that supports interference-free operation of the broadcasting
service stations, which equals 6 dBμV/m.
Values by which the field strength threshold is exceeded and the frequency and territorial separations
required depend on the characteristics and relative location of the amateur service stations and TV
broadcasting station. So, to compensate for the level of interference on the boundary of the TV
broadcasting station’s reception area, additional restrictions should be imposed on amateur service
stations’ e.r.p. in the direction of the boundary of the TV broadcasting station’s reception area, with
the e.r.p. reduced to values below 0 dBW.
The necessary protection distances vary from 70 km to 175 km.
82 Rep. ITU-R M.2478-0
Annex 8
Information concerning current and past sharing arrangements between the
amateur service and other services in the 50-52 MHz frequency band
A8.1 Introduction
This information Annex compiled by IARU details sharing arrangements which have been
implemented by administrations when sharing currently takes place, or has been implemented in the
past between the amateur service and other allocated services in-country, or in a neighbouring
jurisdiction.
The information provided in this Annex originates from administrations, IARU Member Societies or
individual persons who were involved in introducing the sharing criteria.
A8.2 Sharing scenarios
In the mid-1980s some countries in Region 1 were assessing whether VHF television should cease
and spectrum should be transferred to the mobile service. It was at this time that a number of IARU
Member Societies raised with their administrations the possibility of an allocation to the amateur
service in the frequency band 50-54 MHz to align with the allocation in Regions 2 and 3. However
because broadcasting in the frequency band 47-68 MHz (Broadcasting Band 1) ceased at different
times two sharing scenarios arose:
1 When all broadcasting ceased within a territory but neighbouring countries were continuing
with their Band 1 broadcasting.
2 Where administrations felt that they were able to introduce the amateur service within their
own country in locations which were not impacted by their Band 1 transmitters or another
service such as the mobile service or radiolocation service.
This document describes the sharing formulation used in a number of countries and in part was
initiated by sending a questionnaire to IARU Member Societies in CEPT countries. Information
received for a number of countries is reproduced in the following paragraphs.
A8.3 Country information
A8.3.1 Finland
The frequency band 50-52 MHz is allocated to the amateur service on a national secondary basis in
Finland. There are regional restrictions in border areas. Amateur radio transmitters must not be used
in part of the Tohmajärvi Municipality in an area between Niirala, Pykälävaara, Tervavaara,
Lusikkavaara and Ahvenvaara and the border between Finland and the Russian Federation.
Rep. ITU-R M.2478-0 83
The maximum transmitter power in the elementary class is 30 W peak envelope power (PEP) or 120
when the carrier of the transmission is attenuated by at least 6 dB. The maximum transmitter power
in the general class is 150 W PEP or 200 W when the carrier of the transmission is attenuated by at
least 6 dB. For extended power amateur licences there are limits for the field intensity caused by the
amateur station in the Russian area. The calculation model detailed in Recommendation ITU-R
P.1546 is used for the calculation of the field intensity. The limit value of the field intensity is
6 dBuV/m and 10% of time. The same principles are applied to repeaters which are near Russia's
border. In addition the permitted radiation direction for extended power licensees is 0-20 degrees and
150-360 degrees. However the radiation direction of the antenna can be 0-360 degrees when the
elevation angle of the aerial is 15-90 degrees.
A8.3.2 France
Broadcasting Band 1 (47-68 MHz) was not used for television broadcasting in France. However in
December 1997 when the amateur service in France was first authorised to use the band 50.20-51.20
MHz, sharing with mobile video links was implemented. In addition to frequency band limitations
the following restrictions were applied to amateur stations:
– Fixed or portable only (no mobile).
– No repeaters.
– No restriction on antenna type, but restrictions on the radiated power level.
– Access and power levels defined by regions (French “departements”) as per the map below.
84 Rep. ITU-R M.2478-0
Authorized region with radiated power limited to 5 Watts
Authorized region with radiated power limited to 100 Watts
In the regions where use of the band was permitted further restrictions could apply. These restrictions
ended in March 2013.
A8.3.3 Germany
In 1993 the frequency band 50.08–51.00 MHz was released on a national secondary basis in
accordance with Article 4.4 of the Radio Regulations and could be used anywhere in Germany with
the exception of proscribed protection zones, see Fig. A8.1. Amateur licensees within the defined
protection zone were permitted to use the band whenever the TV station was not transmitting.
FIGURE A8.1
Pre 2014 German protection zones marked in red
Only Morse code telegraphy (A1A) and SSB telephony (J3E) were permitted. Power limit: 25 Watt
e.r.p.
Antenna polarization: horizontal. It should be noted that the limitation in power, emission modes and
antenna polarization were based on governmental mobile requirements, NOT for the protection of
analogue television broadcasting. In case of any reported interference to radiocommunication services
and/or cable distribution networks (Cable TV) an amateur had to cease transmissions immediately.
Interference from other radiocommunication services had to be accepted by amateurs. Amateur
Rep. ITU-R M.2478-0 85
operators also had to be available by telephone in order that the administration could inform an
amateur licensee to cease transmissions in case of interference. No mobile operation and no automatic
stations were permitted.
The broadcasting protection zones were removed after the closure of broadcasting stations using the
lower Broadcasting Band 1 channel.
In 2014 further changes were made. The frequency allocation was extended to 50.03–51.00 MHz.
Additional emission classes were introduced and the power limit was changed to transmitter output
power instead of e.r.p. The requirement to be available by telephone has also been dropped since no
interference had been reported.
A8.3.4 Hungary
There are no longer any Band 1 television broadcasting stations in Hungary and no restrictions have
been placed on the amateur service subsequent to the authorizing of the amateur service in 50-52 MHz
other than secondary status e.g. no protection zones or other special provisions. The power limitation
was and remains at 10 W e.r.p.
A8.3.5 Norway
In the past and today in accordance with RR Article 4.4 an amateur licensee is responsible for non-
interference with other services, especially broadcasting in the band 50-52 MHz. In addition prior to
the closure of Band 1 television transmitters the Administration of Norway recommended compliance
with the 50-52 MHz IARU Band-Plan and required that amateur licensees operating in the band 50-
52 MHz comply with the following:
– All emission classes as permitted in the band 144-146 MHz could be used.
– The maximum transmitter power should not exceed 25 W and maximum e.r.p. 60 W.
– Maximum antenna gain 6 dB and maximum antenna height 20 m.
– Obtain a special licence for beacons.
In areas where Band 1, channel 2 used for TV, amateur use of 50-52 MHz was not allowed within a
given radius of TV-transmitters in the periods when the transmitter was active. The proscribed
protection distances are indicated in the Table A8.1.
TABLE A8.1
Transmitter TV transmitter power
(kW)
Sector
(degrees)
Distance
(km)
Main Stations
Greipstad 5 000 – 360 100
Gulen 5 000 – 110
110 – 200
200 – 360
120
120
Melhus 10 000 – 090
090 – 360
130
110
Steigen 10 000 – 110
110 – 360
110
140
Varanger 10 No transmission East of 27 deg or South of 31 deg
Relay Stations
Bødalen 1 000 – 360 20
86 Rep. ITU-R M.2478-0
TABLE A8.1 (end)
Transmitter TV transmitter power
(kW)
Sector
(degrees)
Distance
(km)
Øyer 5 000 – 360 15
Skarmodalen 2.5 000 – 360 25
Åbogan 20 000 – 360 25
Since all use of TV channel 2 in Norway ceased many years ago, the restrictions mentioned in the
above table do not apply for today’s amateur use of the 50-52 MHz frequency allocation granted in
accordance with RR Article 4.4.
A8.3.6 Sweden
Currently there are no geographical restrictions on the use of the band 50.0-52.0 MHz by the amateur
service.
However in 1989 (the start of 50 MHz activities in Sweden), no amateur transmissions were permitted
during television broadcasting hours. A permit was required for each fixed location where 50 MHz
amateur equipment was operated. Subsequently e.r.p. restrictions were introduced in an area around
the television transmitters reflecting the actual protection requirements.
Today the transmitter power limit in Sweden is 200 W PEP. Previously the maximum e.r.p. was
250 W e.r.p. at a specified distance from the TV transmitter and 50 W e.r.p. at a greater distance from
the television transmitter.
There have been no polarizations or antenna pointing restrictions on amateur licensees at any time.
A8.3.7 United Kingdom
Subsequent to WARC-1979 the first 50 MHz experimental permits provided to UK amateurs allowed
operation outside television hours from February 1983. From February 1986 Class A amateur
licensees were permitted to use 50.0-50.5 MHz and the “out of hours” time limits were withdrawn as
Band 1 analogue television services had ceased in the UK. However sharing criteria was developed
to protect the nearest operational Broadcasting Band 1 service area resulting from the Antwerp TV
transmitter in Belgium:
– Maximum power at all times shall be carrier 14 dBW e.r.p., PEP 20 dBW e.r.p.
– Maximum transmitting antenna height to be 20 metres above ground level.
– Antennas shall be horizontally polarised.
– No mobile or 'temporary premises' operation allowed.
– No Repeaters permitted.
In June 1987 the 50 MHz band was also released to Class B licensees and the band was extended to
50-52 MHz. Restrictions were relaxed as Broadcasting Band 1 in Western Europe declined. Vertical
polarization and mobile operation were permitted from April 1991. In July 1994, the e.r.p. limit and
aerial height restriction were removed and a power of 400 Watts (26 dBW) watts permitted in
50-51 MHz with primary status for the Amateur Service on the basis of non-interference to other
services outside the United Kingdom as per RR Article 4.4. The frequency band 51.0-52.0 MHz is
allocated on a Secondary basis with a power limit of 100 W (20 dBW) for Full Licensees, available
on the basis of non-interference to other services inside and outside of the UK, again in accordance
with RR Article 4.4.
Rep. ITU-R M.2478-0 87
A8.4 Summary
This section provides information on various sharing mechanisms that have been introduced by CEPT
administrations in Region 1 over the last 34 years to facilitate the allocation of the frequency band
50-52 MHz to the amateur service under the conditions of RR Article 4.4. It is believed that similar
mechanisms would also be appropriate for the band 52-54 MHz to facilitate a globally harmonized
frequency band allocated to the amateur service between 50 and 54 MHz throughout Region 1.
TABLE A8.2
Summary of operational restriction imposed on the amateur service in some countries when
the broadcasting and amateur services shared all or part of the 50-52 MHz frequency band
Country
Power
restriction
(maximum)
Field strength
limits
Geographic
restriction
Allowed
frequency
range
Other
restrictions
Finland
(NOTE – This
is the only
country where
restriction are
still being
applied)
150 W PEP 6 dBµV/m and
10% of time on
border in some
locations for
stations
operating higher
power stations
Operation not
allowed in
specified part areas
near the FIN/RUS
border.
50-52 MHz None
Germany 25 W e.r.p. None Operation not
allowed in some
specified areas
50.08-51 MHz Limited to
narrow band
modes.
Hungary 10 W e.r.p.
Norway 60 W e.r.p. None 100-140 km zones
around specified
main TV stations.
15-25 km zones
around specified
relay stations.
50-52 MHz Limitations on
antenna gain and
height.
Sweden 250 W e.r.p. None 50-52 MHz Operation only
allowed after the
TV station
ceased
transmission at
night time. A
permit was
required for each
fixed location
where 50 MHz
amateur
equipment was
operated.
88 Rep. ITU-R M.2478-0
TABLE A8.2 (end)
Country
Power
restriction
(maximum)
Field strength
limits
Geographic
restriction
Allowed
frequency
range
Other
restrictions
United
Kingdom
100 W e.r.p. None None 50-50.5 MHz No Repeater or
mobile
operation.
Maximum
antenna height of
20 m. Operation
only allowed
after the TV
station ceased
transmission at
night time.
NOTE – Primary
allocation at
national level.
Australia Mode dependent
but 100 W PEP
None 120 km zones
around specified
main TV stations.
60 km zones
around specified
relay (translator)
stations.
50.0-50.3 MHz
only in NSW,
ACT, VIC and
QLD, no
restrictions
elsewhere.
No restriction
in band 52-54
MHz
None
TABLE A8.3
Summary of restrictions imposed in two countries to protect the land mobile
or other incumbent services in the 50-52 MHz frequency band
Country Power restriction
(maximum)
Geographic
restriction
Frequency
restrictions Other restrictions
France 5 W e.r.p., 100 W
allowed in a small
number of regions
Operation not
allowed in some
“departments”
50.2-51.2 MHz
only
No repeaters.
Fixed or portable
only i.e. no mobile
operation.
Germany 25 W PEP 50.03-51.0 MHz
Rep. ITU-R M.2478-0 89
Annex 9
Background information on TV in Region 1
A9.1 Broadcasting plans
In addition to the RR Article 5 allocation to the broadcasting service in Region 1 mentioned in
noting d), the band continues to be subject to both the Final Acts of the European Broadcasting
Conference (Stockholm, 1961 as revised in Geneva, 2006) (“ST61”) in the European Broadcasting
Area and the Final Acts of the African Broadcasting Conference (Geneva, 1989 as revised in Geneva,
2006) (“GE89”) in the African Broadcasting Area and neighbouring countries.
The ITU-R eQry database also shows that there are a total of 353 broadcasting assignments recorded
in the ST61 and GE89 plans still using the frequency range 50-54 MHz in 41 administrations. The
MIFR contains 555 broadcasting transmitters in that band in Region 1. This information is shown in
Table A9.1 below:
TABLE A9.1
Date IFIC no. ST61 GE89 Region 1 MIFR Region 1
24/10/2016 2831 292 56 555
TV entries falling into or overlapping with frequency range 50 MHz-54 MHz. The information
submitted to the BR for recording in the MIFR may not necessarily include all broadcasting stations
in operation thus it may not reflect the actual use of the frequency band.
A9.2 The 2016 Situation
In the European Regional Telecommunications Organization (RTO), CEPT administrations have
been urged to remove their unused assignments to the broadcasting service in the band 50-54 MHz
in view of agenda item 1.1 of WRC-19. This action will be in line with an earlier decision to protect
assignments according to the Stockholm Agreement 1961 Plan.
The CEPT over a number of decades has developed a European Common Allocation (ECA) table,
which is reviewed annually. Footnote ECA3 states 'CEPT administrations are urged to take all
practical steps to clear the band 47-68 MHz of assignments to the broadcasting service. The
broadcasting assignments according to Stockholm Agreement 1961 shall be protected.' At a recent
CEPT meeting administrations agreed that it could be useful if the totality of Broadcasting Band 1
could be addressed in accordance with ECA3 and unused assignments listed in the MIFR suppressed.
ECA3 will therefore be reviewed at future meetings when the ECA is addressed.
The closure of analogue television in the 47–68 MHz frequency band relates directly to the
introduction of digital television. In 2009, the European Commission promoted a coordinated
approach to the freeing up and future use of the radio spectrum because it wanted to ensure that EU
citizens could enjoy the benefits of digital television. For that to happen, Member States (and other
CEPT countries) closed analogue transmissions and moved to digital broadcasting. The switch-off of
analogue terrestrial TV transmission was completed by 2009 in Germany, Finland, Luxembourg,
Sweden and the Netherlands. The 2012 EU target for switch-off was met by almost all Member States
of the European Union.
The MIFR does not reflect this result. The current situation is that in Western Europe the 47-68 MHz
frequency band is no longer used for terrestrial television broadcasting to the general public.
90 Rep. ITU-R M.2478-0
A9.3 Digital Terrestrial Television Broadcasting in Band 1: 47-68 MHz
The Chester July 1997 Multilateral Coordination Agreement (MCA) attended by 34 CEPT
administrations representing Member countries of the ITU was convened under the terms of Article 6
of the ITU Radio Regulations and dealt with the technical criteria as well as coordination principles
and procedures for the introduction of Digital Terrestrial Television Broadcasting (DTTB). Article 4
of the Multilateral Co-ordination Agreement states that coordination procedures only deal with the
frequency bands in which DTTB is envisaged, i.e. 174 to 230 MHz and 470 to 862 MHz. In the other
bands the procedures of the 1961 Stockholm Agreement (ST61) would apply, without additional
procedures.
Furthermore, the joint CEPT ERC/EBU Report on Planning and Introduction of Terrestrial Digital
Television (DVB-T) in Europe, Izmir, December 1997 states in section D2-2 “Due to long distance
propagation effects and the high man-made-noise level, Band I is not considered suitable for DVB-T”.
During consultations carried out by ITU Secretary General in 2000/2001 an overwhelming majority
of the countries of the European Broadcasting Area indicated their support for the proposed revision
of ST61. In addition, Member States from the planning area of the Regional Agreement for VHF/UHF
television broadcasting (GE89) in the African Broadcasting Area (ABA) and neighbouring countries
also expressed the wish to convene a Regional Radiocommunication Conference (RRC) for the same
purposes.
The ITU Council, at its sessions in 2001 and 2002, adopted Resolutions 1185 and 1180, by which it
agreed to the convening of a RRC on the planning of terrestrial broadcasting in the VHF/UHF bands,
for the combined planning area covering the European Broadcasting Area (EBA), the African
Broadcasting Area, and the countries outside the African Broadcasting Area which are parties to the
Regional Broadcasting Agreement, Geneva, 1989.
The Plenipotentiary Conference, Marrakesh, 2002, also considered this issue and decided to extend
the planning area to the territories of the following countries that are not or only partially covered by
the planning areas of both the ST61 and GE89 Agreements: Armenia, Azerbaijan, Georgia,
Kazakhstan, Kyrgyzstan, Russian Federation (the part of the territory to the west from longitude
170° E), Tajikistan, Turkmenistan and Uzbekistan (see Resolution 117 (Marrakesh, 2002)).
In summary, the planning area comprised those parts of Region 1 that are situated west of the meridian
170° East and north of the parallel 40° South, as well as the whole territory of the Islamic Republic
of Iran.
The expectation that the band 47–68 MHz will not be utilized for DTTB in Region 1 continues in the
ITU-R documentation, especially Report ITU-R BT.2387-0 (07/2015) which contains information
from administrations on the current and future use of various frequency bands, including 50-54 MHz
for broadcasting. None of the responding administrations identified VHF1 spectrum for their current
or future DTTB services. However it is likely that several countries in Region 2 may adopt or have
adopted the ATSC DTTB standard in spectrum allocated to the Broadcasting Service above 54 MHz.
In May 2019 the Russian Federation stated that it was considering the use of the frequency band
50-54 MHz for digital broadcasting, so potential use of that band for such a purpose could not be
ruled out.
The frequency band 48-56 MHz is also being considered by some administrations as a candidate band
for deploying digital TV and multimedia broadcasting systems. There are proposals to expand the use
of DVB-T2 for bands below 174 MHz and to implement enhanced sound and multimedia
broadcasting systems in the lower portion of the VHF band, including frequencies from 50 MHz to
54 MHz.
Rep. ITU-R M.2478-0 91
A9.4 Analogue Television Broadcasting in Band 1: 47-68 MHz
Report ITU-R BT.2387-0 (07/2015) clearly indicates that low VHF spectrum is not generally
considered by administrations to be suitable for DTTB. As national Analogue Switch Off (ASO)
programmes are completed, the number of analogue television stations diminishes in those countries
where DTTB has been fully implemented. However there are a large number of analogue stations
assigned frequencies in the VHF band below 100 MHz which are still in operation, for example 2 091
in Brazil above 54 MHz and 3 683 in the Russian Federation, some of which will be in the 47-54 MHz
frequency band. It therefore appears that analogue television in VHF1 spectrum remains a cost
effective means of reaching viewers in remote areas of large countries.
Another important consideration is that many of the remaining analogue broadcasting stations in
Region 1 were planned using the criteria and Plan assignments detailed in ST61 and GE89. On the
assumption that those countries which have completed their ASO have decommissioned their
analogue transmitters that the interference environment for those stations which remain operational
has as a result significantly improved and the combined interference potential of several hundred
amateur stations spread across the countries of central and western Europe is likely to be significantly
less than the situation when the band was utilized solely for television broadcasting.
Nevertheless, it may in some situations be necessary to develop mechanisms to limit the possibility of
harmful interference being caused by the amateur service to broadcasting reception in the 50-54 MHz
frequency band in Region 1, until such time that the broadcasting stations cease operations.
Annex 10
A Monte-Carlo simulation of sharing with the mobile service
This Annex contains the results of a Monte-Carlo simulations performed using the SEAMCAT
software tool to assess the possibility of co-channel sharing in the frequency band around 52 MHz
between a proposed governmental tactical communications system and the amateur service.
The results indicate that under the most likely circumstances the probability of co-channel
interference is low and contained within a very limited area. A protection distance of 40 km, to
separate the tactical and amateur stations, could be applied if required though under most
circumstances the interference would be transitory due to the very different operational characteristics
of the tactical system and amateur service.
A10.1 Introduction
There is a need to undertake appropriate sharing studies between various services and the amateur
service for WRC-19 agenda item 1.1 which is considering the possibility of a new amateur service
allocation in the 50-54 MHz frequency band. This contribution presents a sharing study between a
proposed government tactical communications system and the amateur service for a number of
scenarios in the 50-54 MHz frequency band.
A10.2 Background
Recommendation ITU-R M.1634 notes under considering:
“c) that deterministic interference calculations may not give a complete picture of the
severity of the interference, for example, in terms of percentage of time;
92 Rep. ITU-R M.2478-0
d) that deterministic calculations are simple but may result in important decisions being
made which overlook potentially useful sharing opportunities;
e) that probabilistic interference calculations can provide significantly improved insights
that enable more informed decisions regarding use of radio spectrum;”
Recommendation ITU-R M.1634 further states that the software tool known as SEAMCAT is an
appropriate method for undertaking the recommended probabilistic sharing studies. SEAMCAT was
developed by the group of European Conference of Postal and Telecommunications Administrations
(CEPT), European Telecommunications Standardization Institute (ETSI) members and international
scientific bodies. SEAMCAT is publicly available along with relevant reference and user
documentation at: http://www.cept.org.
This Annex presents the results of SEAMCAT simulations covering a number of scenarios that are
thought to represent a worst case situation when considering contemporary technology of the amateur
service and a proposed government tactical communication system that may be used in the 50-54
MHz frequency band.
A10.3 The study scenarios and basic system parameters
This SEAMCAT simulation study covers six situations in a rural environment with both the ‘victim’
(tactical system) and the ‘interfering’ (amateur station) links operating on the same frequency of 52
MHz:
– Base station transmitting to vehicle receiver.
– Base station transmitting to handset receiver.
– Vehicle transmitting to base station receiver.
– Vehicle transmitting to handset receiver.
– Handset transmitting to base station receiver.
– Handset transmitting to vehicle receiver.
Each simulation was run for 20 000 individual random positions with the amateur transmitter free to
operate anywhere within a 40 km radius of a tactical transmitter. All the relevant SEAMCAT
parameters are given in Table A10.1.
TABLE A10.1
The main parameters used for the SEAMCAT studies given in this document. Any other
parameters not specified were left as the program default values. SEAMCAT
version 4.1.0 revision 2337 was used for this study
Parameter Value Comments
Amateur transmitter power SSB: 50 dBm (100 W) PEP Typical of amateur equipment used
around 52 MHz. The emission mask
is shown in Fig. A10.2.
Duty cycle of amateur transmitter SSB: 2.5% at 40 dBm and 2.5%
at 50 dBm
5% operation is 1.2 hours per day;
most amateurs would transmit less
than this on average. Considering
SSB; for smoothly read text, the
mean power of the speech signal is
10 dB lower than the power of a
reference sinusoidal signal (see
Rec. ITU-R SM.326, Note 2 to
Table 1).
Rep. ITU-R M.2478-0 93
TABLE A10.1 (end)
Parameter Value Comments
Amateur links antennas, RX &
TX
4 element Yagi, 9.4 dBi gain Typical amateur antennas. See
Figure A10.1 for radiation pattern.
Amateur antenna height, RX &
TX
10 m (above ground) A probable maximum amateur
height due to planning
requirements.
Number of active amateur
transmitters in service area
1
Base station transmitter power 47 dBm (50 W)
Vehicle transmitter power 47 dBm (50 W)
Handset transmitter power 37 dBm (5 W)
Tactical base station antenna Omni-directional vertical, 2.15
dBi gain, 8 m high
See Fig. A10.3 for radiation pattern.
Vehicle antenna Omni-directional vertical, –3
dBi gain, 2 m high
See Fig. A10.3 for radiation pattern.
Handset station antenna Omni-directional vertical, –10
dBi gain, 1.5 m high
See Figure A10.3 for radiation
pattern.
Tactical service receiver
sensitivity
–112 dBm (0.56 uV into 50
ohms)
Mobile link bandwidth and
modes
16 kHz
Mobile service interference
criteria
C/I = 16.97 dB
C/(N+I) = 10 dB
(N+I)/N = 0.97 dB
I/N = –6 dB
10 dB SINAD and –6 dB I/N
specified
Mobile service noise floor –126.9 dBm Based on the fundamental
calculation of noise power per Hertz
(kTB), corrected for bandwidth (16
kHz) and receiver noise figure (4
dB):
–129 dBm = –174 dBm/Hz +
10log(BW) + NF
Coverage radius 40 km for amateur
1 to 40 km for tactical system
General environment Rural, over land
Propagation model Extended-Hata Suitable for elevated transmitters in
a cluttered, non-line-of-site
environment between 30 MHz and
3 GHz up to a maximum range of
100 km
The transmission mode of the amateur station is single sideband suppressed carrier (SSB) using a 100 W
Peak-Envelope-Power (PEP) transmitter operating with a duty cycle of 5% which represents 1.2 hours
of transmission per day. The amateur transmit and receive antennas have a gain of 9.4 dBi and are
located 10 m above ground (Fig. A10.1). The emission mask of the amateur signal is shown in
Fig. A10.2.
94 Rep. ITU-R M.2478-0
FIGURE A10.1
Radiation pattern of the 4 element Yagi used in this study. Side lobes have not been included as the random assignment of
directions in the simulation covered all possibilities of direction by the main lobe.
FIGURE A10.2
Emission mask for the SSB transmissions made by the amateur station transmitter used in this study.
Rep. ITU-R M.2478-0 95
FIGURE A10.3
Radiation pattern of the 2.15 dBi antenna used in this study. The other omni-directional antennas have the same pattern but
use different gains in place of 2.15 dBi as shown here.
The ‘victim’ (tactical) system specifications used for the SEAMCAT studies are shown in
Tables A10.2 through A10.5.
TABLE A10.2
Main tactical System parameters
System type Governmental tactical
Frequency range 30-88 MHz (52 MHz used)
Receiver bandwidth 16 kHz
Protection criteria I/N = –6 dB
Thermal noise density –169 dBm/Hz
Receiver sensitivity –112 dBm for 10 dB SINAD
Deployment environment Rural, over land
TABLE A10.3
Vehicular parameters
Antenna height 2 m
Antenna polarization Linear Vertical
Antenna gain –3 dBi
Antenna radiation pattern Omnidirectional
Transmitter power 50 W
96 Rep. ITU-R M.2478-0
TABLE A10.4
Handset parameters
Antenna height 1.5 m
Antenna polarization Linear Vertical
Antenna gain –10 dBi
Antenna radiation pattern Omnidirectional
Transmitter power 5 W
TABLE A10.5
Base station parameters
Antenna height 8 m
Antenna polarization Linear Vertical
Antenna gain 2.15 dBi
Antenna radiation pattern Omnidirectional
Transmitter Power 50 W
Using the parameters specified for the Protection Criteria of I/N = –6 dB and 10 dB SINAD the
equivalent SEAMCAT Noise Floor and Interference Criteria were calculated and a given in
Table A10.6.
TABLE A10.6
SEAMCAT noise floor and interference criteria used for this study
Noise floor –126.9 dBm = –169 + 10 log10(16000)
C/I 16.97 dB
C/(N+I) 10 dB
(N+I)/N 0.97 dB
I/N –6 dB
A10.4 Operational considerations
Tactical systems are likely to be deployed rapidly in response to various situations, operate for a
relatively short period of time (hours to days) and then be stood down or moved to another area. The
vehicular and handset assets are likely to be highly mobile and move continuously or intermittently
throughout the service area, not remaining in any given position for an extended period of time. The
handset devices carried by the user have a limited range and the user is highly likely to remain in close
proximity to the host vehicle at all times otherwise communication may be lost.
Stations of the amateur service are relatively sparse, static and located in homes or temporary field
sites. In general they are highly visible and their location or proximity is known because of national
licensing requirements and all transmissions are clearly identified by the call-sign of the transmitting
station. Amateur stations operate intermittently and much more time is spent listening than
transmitting. A typical amateur operator is only likely to be operational for an hour or two each day,
or a few hours a week.
Rep. ITU-R M.2478-0 97
A final factor to consider is that most amateur antennas likely to be used around 52 MHz are
horizontally polarized versus the vertical polarization of the tactical system. This cross-polarization
is not taken into account in this study but its presence in the actual usage of the band under
consideration would reduce the interfering signal strength in the range 6 to 185 dB which would
further decrease the probability of interference.
A10.5 Estimating the service range of the tactical links
The first step undertaken in this study was to estimate the likely service range of the tactical system
from the parameters provided. In particular, the specified receiver sensitivity of –112 dBm for a 10 dB
SINAD sets the lower limit for the required signal strength and defines the maximum likely
operational range.
SEAMCAT simulations were run for the six scenarios over a variety of coverage radii and the predicted
mean desired signal strength (dRSS) and standard deviations were recorded and compared to the
minimum required signal strength. The radius of the service area was taken to be that given by the mean
desired signal strength minus two standard deviations. This implies that approximately 97% of all
possible paths in the service area will be above the minimum signal strength of –112 dBm. dRSS is the
predicted mean desired signal strength i.e. of the tactical service, in a service area with the radius shown.
If the value dRSS – 2.StdDev falls below approximately –112 dBm the link does not meet its required
performance criteria. The results of these calculations are shown in Table A10.7.
TABLE A10.7
Predicted ranges of tactical devices in various configurations based on the minimum
acceptable signal strength of 112 dBm for a 10 dB SINAD.
Link Radius
(km)
dRSS
(dBm)
StdDev
(dBm)
dRSS – 2.StdDev
(dBM)
Base to vehicle 40 –88.56 12.21 –112.98
Base to handset 15 –87.42 11.87 –111.16
Vehicle to base 40 –88.57 12.1 –112.77
Vehicle to handset 3 –86.93 12.73 –112.39
Handset to base 7.5 –87.02 11.96 –110.94
Handset to vehicle 1 –91.19 10.64 –112.47
The service ranges show significant variation due to the differences in transmitter power, antenna
gain and antenna elevation and these ranges will dictate the use and positioning of the individual
tactical system assets. This SEAMCAT study uses the above predicted transmission ranges as the
basis for assessing the compatibility of the tactical and amateur service communication links.
A10.6 Range of the amateur service links assumed in this study
The second part of this study assumes there is one active amateur transmitter (‘interfering’
transmitter) in a radius of 40 km around a tactical system transmitter and both systems are operating
on the same frequency. As the amateur service does not have a defined service area, transmissions
from the amateur stations are to other amateur station receivers which may be either inside or outside
5 The adjustment factor resulting from the antenna polarization discrimination for horizontally polarised
broadcasting emissions with respect to vertically polarised mobile emissions is –18 dB, from section 4.1 of
Recommendation ITU-R SM.851-1.
98 Rep. ITU-R M.2478-0
of the tactical service area. In this case it is assumed that the amateur receiver can be within a radius
of 40 km of any position that the amateur transmitter may occupy. This implies that in some cases
the tactical system assets may be very close to an amateur station, or relatively far away in other cases
and this is to be expected as the tactical system is not a fixed installation and may be deployed in any
position relative to an amateur station. Figure A10.4 shows this study scenario.
In this study the test areas for each service completely overlap and in normal practice an amateur
station would not transmit on an occupied frequency, so the situations presented in this simulation
would not usually occur in practice as the amateur station would be aware that a tactical station was
already using the frequency.
FIGURE A10.4
The SEAMCAT simulation for the Base-to-Handset scenario which has a 15 km service range, with the relative positions of
the tactical and amateur stations free to move within the entire 40 km radius amateur transmitter area. The figure shows just
401 positions of the 20 000 random positions actually used to calculate the interference statistics
A10.7 Results of the simulations
This study assumes that the amateur transmitter is within a 40 km radius of a tactical system
transmitter, operating on the same frequency and with the tactical receiver operating anywhere within
Rep. ITU-R M.2478-0 99
its defined service area. Table A10.8 shows the predicted average probability of interference for the
scenarios and it can be seen that the probability of interference is generally small and the tactical links
generally function without interference for more than 95% of the time for the given
10 dB C/I protection criteria. Those scenarios that do have a higher probability of interference
(vehicle-to-base and handset-to-base) are all mobile situations that are highly likely to be transient as
the relative distance between the tactical assets and amateur station changes. The Table also shows
that the I/N criteria is not a good indicator of compatibility for this type of application as the position
of the victim and interfering systems are likely to be constantly moving and that while the I/N criteria
may be exceeded the ultimate Signal to Noise Ratio is acceptable.
TABLE A10.8
Predicted co-channel average interference probability for each study scenario assuming the
tactical assets are operating within their operating ranges and with the amateur station
transmitting anywhere within a 40 km radius of a tactical transmitter
Link Radius
(km) C/I% (17 dB)
C/(N+I)%
(10 dB)
I/N%
(–6 dB)
Base-to-vehicle 40 2.73 1.78 14.16
Base-to-handset 15 1.11 0.66 6.43
Vehicle-to-base 40 8.73 5.47 38.11
Vehicle-to-handset 3 1.19 0.66 6.45
Handset-to-base 7.5 10.1 6.25 44.65
Handset-to-vehicle 1 3.82 2.44 17.53
A10.8 Conclusion
Using Monte-Carlo simulators such as SEAMCAT allow various scenarios to be examined relatively
quickly. The simulations discussed above are thought to represent typical worst case situations that
might be encountered if a tactical service and amateur service coexist in the 50-54 MHz band.
Notwithstanding that the co-channel interference probability is low in some cases and moderate in
others it would appear that any interference which is likely to occur would be transient, probably be
in the same jurisdiction as the tactical system and could be handled by national provisions in place
for the use of the radio spectrum, which might include bilateral or multilateral agreements in place
with neighbouring countries.
Annex 11
Minimum Coupling Loss sharing study between amateur
radio stations and governmental mobile systems
This Annex aims to evaluate to which extent an amateur radio transmitter would interfere with mobile
radio equipment. This investigation is undertaken for different scenarios with a distinct set of
parameters for each scenario, such as: antenna heights, topological conditions and emission masks of
the amateur radio transmitter. The simulations are based on a minimum coupling loss approach.
100 Rep. ITU-R M.2478-0
A11.1 Propagation model
Radio wave propagation is calculated for 3 different propagation scenarios representing flat as well
as hilly terrain respectively mountainous environment. Detailed representation of the scenarios are
shown in Attachment 2 to this Annex. Propagation effects are calculated according to the model of
Recommendation ITU-R P.2001-2 (4).
The results are subject to statistical fluctuations6. The calculated losses show values for a probability
of 10% respectively 50% of all possible cases. At low probabilities, propagation effects such as
tropospheric scattering become more important making the propagation loss decreasing. In ECC
Recommendation T/R 25-08 “Planning criteria and coordination of frequencies for land mobile
systems in the range 29.7-470 MHz” indicative coordination thresholds are calculated based on 10%
propagation probability. However, in the following both the probability values of 10% and 50% are
considered. Therefore the calculated values on a probability parameter of 50% indicate a somewhat
optimistic interference scenario.
No clutter loss is considered. As stated in Recommendation ITU-R P.2001-2, section 1.1, the model
is believed to be most accurate for distances from about 3 km to 1 000 km. At shorter distances, the
effect of clutter will tend to dominate unless the antenna heights are high enough to give an
unobstructed path. It can be seen in section Appendix 4 to this Annex that the interference ranges are
often significantly longer than 3 km. The antennas heights are 8 m or more for all type of amateur
radio stations and for the base station victim receiver. Only the vehicular and the handset receiver
antenna heights are below 8 m. The considered radio stations often operate in rural environment,
where the clutter height can be assumed to be below 8 m. Therefore the calculation is somewhat
conservative for short interference distances (d < 3 km) in the cases of handset and vehicular victim
radio receivers.
A11.2 Global approach
In order to evaluate the interference ranges of amateur radio transmitters for different propagation
scenarios, the following calculation method is executed in four consecutive steps:
1 The required protection level is evaluated with a protection criterion of I/N = –6 dB based on
ambient noise figure according to Recommendation ITU-R P.372-13 (5).
2 The radiated power for co- and adjacent channels is calculated.
3 The minimum required path attenuation is calculated to meet the required protection level.
4 The interference range is evaluated by means of the calculated minimum path attenuation
and evaluated path attenuation for six different propagation scenarios, respectively path
profiles.
A11.3 Protection criterion and ambient noise figure
For mobile radios, a protection criterion of I/N = –6 dB is specified. According to Recommendation
ITU-R P.372-13 (5), natural background noise (dominated by galactic noise) corresponds to a noise
figure of F = 15 dB at a frequency of 50 MHz. The maximum acceptable interference power for the
mobile Service 𝑃𝑝𝑟𝑜𝑡𝑒𝑐𝑡,is calculated as follows:
𝑃𝑝𝑟𝑜𝑡𝑒𝑐𝑡 = 𝑁0 + 𝐹𝑠 + 10 log(𝐵𝑊) − 𝐼
𝑁
6 With spherical diffraction, attenuation effects occur which depend on the gradient of the local dielectric
characteristics of the environment. These are considered in the model as statistical parameters.
Rep. ITU-R M.2478-0 101
where 𝑁0 is the thermal noise power at a temperature of 20°C, BW is the receiver bandwidth and Fs =
16.2 dB is the noise figure of the added ambient noise and receiver noise.
Accordingly, the maximum acceptable interference power for mobile service application is calculated
as follows:
−𝟏𝟐𝟏. 𝟖 𝒅𝑩𝒎 = −174𝑑𝐵𝑚
𝐻𝑧+ 16.2𝑑𝐵 + 10log (16 𝑘𝐻𝑧) − 6 𝑑𝐵
The values for the ambient noise figure F defined in Recommendation ITU-R P.372-13 (5) relate to
measurements with a vertical dipole or monopole antenna. In the given case, the victim antennas
(mobile service) also show isotropic directivity in the azimuth, though with a gain which differs from
the Recommendation's notional ideal antennas. However, because the ambient interference is
substantially higher than the level of the receiver's internal noise, the gain of the victim antenna needs
not be considered for calculation of ambient noise.
It should also be noted that the assumed ambient noise figure of 15 dB for antennas with increased
directivity in the horizontal direction has been set somewhat too high. If corresponding antennas (with
increased directivity in the elevation) are used at the victim receiver, the computed interference ranges
represent a minimum, as in this case galactic noise actually reduces receiver sensitivity by less than
the determined 16.2 dB.
A11.4 Radiated power for co- and adjacent channels
The calculated transmit interference power 𝑃𝐸 of amateur radio transmitters is determined on the basis
of two different emission masks: Option 1 mask and Option 2 mask (Appendix 1 to this Annex). In
the SSB interference study, consideration is given to the fact that the bandwidth of the receiver
affected by the interference (16 kHz) is greater than that of the interference signal (3.0 kHz). The
calculated interference powers at the transmitter output of the interference source, corrected for
bandwidth, are shown in Appendix 3 to this Annex.
A11.5 Determination of minimum path attenuation
The minimum path losses which are necessary to guarantee that the reception level of the interference
signal remains below the value of the protection value are determined. Then, the minimum distance
between the interfering transmitters and the victim receiver can be determined from the computed
path loss curves.
The minimum path losses 𝐴𝑆 is calculated as:
𝐴𝑆 = 𝑃𝐴𝑚𝑎𝑡 + 𝐺𝐴𝑚𝑎𝑡 + 𝐵𝑊𝐶𝑜𝑟𝑟 − 𝑃𝑜𝑙𝑚𝑖𝑠 − 𝑃𝑝𝑟𝑜𝑡𝑒𝑐𝑡
where:
𝑃𝐴𝑚𝑎𝑡: is the emission power of the amateur station, in dBm;
𝐺𝐴𝑚𝑎𝑡: is the Amateur station antenna gain, in dBi;
𝐵𝑊𝐶𝑜𝑟𝑟: is a correction for calculation of power density, due to the fact that interferer and
victim operate with a different signal bandwidth, it applies only if the interferer
bandwidth is greater than the victim bandwidth 𝐵𝑊𝐶𝑜𝑟𝑟 = 10 ∗ log (BWMob/BWAmat), in dB;
𝑃𝑜𝑙𝑚𝑖𝑠: is the polarization mismatch considered to be 3 dB for the SSB mode and 0 dB
for FM and wideband modes.
Because the ambient noise figure is higher than the receiver noise figure, the gain of the receiving
antenna is not taken into account.
102 Rep. ITU-R M.2478-0
A11.6 MCL Results
Achieved results are depicted in § 5.2.
Attachment 1
to Annex 11
Amateur radio transmission mask
The out of band emission masks of amateur equipment are defined in Recommendation ITU-R
SM.1541-6 Annex 9 and are represented in Figs A11.1 and A11.2 for narrowband and wideband
applications. Those masks are somewhat conservative definitions. Often, amateur radio transmitters
exhibit smaller adjacent channel emissions than represented in Recommendation ITU-R SM.1541-6.
In order to take this fact into account, an additional spectrum mask (Option 2) is defined for the
compatibility studies to be carried out. This is plotted graphically in Figs A11.3, A11.4 and A11.5.
FIGURE A11.1
OoB emissions of amateur stations in operation above 30 MHz in the normal or narrowband
applications as defined in Rec. ITU-R SM.1539-1
SM.1541-37
Frequency offset from the centre of the emission in percentage of necessary bandwidth BN
Att
enua
tio
n (
dB)
rela
tiv
e to
mea
n p
ower
58 dB - limit case for 500 WP
58 dB - limit case for 500 W, RBW = 10 kHzP
0 50
20
10
0
30
40
150
50
200 250100
60
70
10 dB
120% BN 225% BN
31 + 10 log dB ( = 1), RBW = 1 kHzP P
38 + 10 log ( = 1), RBW = 10 kHzP P
RBW = 1 kHz
Rep. ITU-R M.2478-0 103
FIGURE A11.2
OoB emissions of amateur stations in operation above 30 MHz for wideband
applications as defined in Rec. ITU-R SM.1539-1
For ‘spurious emissions’, the values specified in the ETSI standard EN 301 783 V.2.1.1 (1), as shown
in Table A11.1, are used.
The appropriate measurement bandwidths are specified in the respective standards as 100 kHz.
TABLE A11.1
Limit values for spurious emissions according to ETSI EN 301 783 V.2.1.1
It is not evident from ETSI standard EN 301 783 (1) how mobile SSB transmitters differ from other
transmitters or when an item of equipment is classified as ‘mobile SSB equipment’. However, it is
evident that ‘mobile SSB equipment’ with a transmitter power of more than 1 W causes ‘spurious
emissions’ which are above the limit of other transmitters.
It must also be assumed that in SSB operation the ‘spurious emissions’ decrease as the frequency
spacing in relation to the carrier frequency increases. This is the nature of intermodulation
104 Rep. ITU-R M.2478-0
interference. Accordingly, one could assume that interference with very large frequency spacing in
relation to the carrier frequency is well below the limit value.
FIGURE A11.3
Emission masks (e.i.r.p.) with reduced adjacent channel power for narrowband operation
FIGURE A11.4
Emission masks (e.i.r.p.) with reduced adjacent channel power for FM operation
-40
-30
-20
-10
0
10
20
30
40
50
60
0 5 10 15 20
pow
er
density
(dB
m/k
Hz)
frequency (kHz)
Emission mask (e.i.r.p.) at 3.0 kHz bandwidth and 9.4 dBi antenna gain
Option 1
Option 2
-60
-50
-40
-30
-20
-10
0
10
20
30
40
0 10 20 30 40 50 60
pow
er
density
(dB
m/k
Hz)
frequency (kHz)
FM emission mask (e.i.r.p.) at 16.0 kHz bandwidth and 2.5 dBi antenna gain
option 1
option_2
Rep. ITU-R M.2478-0 105
FIGURE A11.5
Emission masks (e.i.r.p.) with reduced adjacent channel
Attachment 2
to Annex 11
Propagation scenarios for MCL calculations
To determine path loss, the following model cases are calculated using the propagation model
according Recommendation ITU-R P.2001:
Scenario 1
• Flat terrain propagation condition
• Probability in time = 10%
• Interferer antenna height = 1 000 m, 20 m and 10 m
• Victim antenna height= 1.5 m, 2 m, 8 m
Scenario 2
• Flat terrain propagation condition
• Probability in time = 50%
• Interferer antenna height = 1 000 m, 20 m, 10 m
• Victim antenna height = 1.5 m, 2 m, 8 m
-70
-60
-50
-40
-30
-20
-10
0
10
20
30
0 100 200 300 400 500 600 700 800
Pow
er
density(
dB
m/k
Hz)
frequency (kHz)
Emission mask (e.i.r.p.) at 300 kHz bandwidth and 4 dBi antenna gain
Option 1
Option 2
106 Rep. ITU-R M.2478-0
Scenario 3
• Hilly terrain propagation condition for the propagation between the two Swiss cities Yverdon
and Laufenburg
• Probability in time = 50%
• Interferer antenna height = 10 m
• Victim antenna height 1.5 m
Propagation effects are calculated according to the model of Recommendation ITU-R P.2001-2 (4).
The results are subject to statistical fluctuations7. The calculated losses show values for a probability
of 10% respectively 50% of all possible cases. At low probabilities, propagation effects such as
tropospheric scattering become more important making the propagation loss decreasing.
In ECC Recommendation T/R 25-08 “Planning criteria and coordination of frequencies for land
mobile systems in the range 29.7-470 MHz” indicative coordination thresholds are calculated based
on 10% propagation probability. However, in the following the probability values of 10% and 50%
are considered. Therefore the calculated values on a probability parameter of 50% indicate a
somewhat optimistic interference scenario.
No clutter loss is considered. As stated in Recommendation ITU-R P.2001-2, section 1.1, the model
is believed to be most accurate for distances from about 3 km to 1 000 km. At shorter distances, the
effect of clutter will tend to dominate unless the antenna heights are high enough to give an
unobstructed path. It can be seen in Attachment 4 to this Annex, that the interference ranges are often
significantly longer than 3 km. The antennas heights are 8 m or more for all type of amateur radio
stations and for the base station victim receiver. Only the vehicular and the handset receiver antenna
heights are below 8 m. The considered radio stations often operate in rural environment, where the
clutter height can be assumed to be below 8 m. Therefore the calculation is somewhat conservative
for short interference distances (d < 3 km) in the cases of handset and vehicular victim radio receivers.
Some path loss curves for the three above mentioned scenarios are shown in Figs A11.6 to A11.8. It
is interesting to note, that in hilly terrain situations, the attenuation may be lower than in flat terrain
situations, even in case of multiple bullington diffraction.
7 With spherical diffraction, attenuation effects occur which depend on the gradient of the local dielectric
characteristics of the environment. These are considered in the model as statistical parameters.
Rep. ITU-R M.2478-0 107
FIGURE A11.6
Path loss on flat terrain for time probability = 10% and the following antenna height parameters:
red curve: Transmitter height = 1 000 m, receiver height = 8 m
yellow curve: Transmitter height = 1 000 m, receiver height = 1.5 m
blue curve: Transmitter height = 10 m, receiver height = 8 m
green curve: Transmitter height = 10 m, receiver height = 1.5 m
0 50 100 150 200 250 300 350 400 450 50080
90
100
110
120
130
140
150
160
170
180
distance [km]
antt
enuation [
dB
]
108 Rep. ITU-R M.2478-0
FIGURE A11.7
Path loss on flat terrain for time probability = 50% and the following antenna height parameters:
red curve: Transmitter height = 1 000 m, receiver height = 8 m
yellow curve: Transmitter height = 1 000 m, receiver height = 1.5 m
blue curve: Transmitter height = 10 m, receiver height = 8 m
green curve: Transmitter height = 10 m, receiver height = 1.5 m
0 50 100 150 200 250 300 350 400 450 50080
90
100
110
120
130
140
150
160
170
180
distanc [km]
att
enuation [
dB
]
Rep. ITU-R M.2478-0 109
FIGURE A11.8
Path loss and terrain profile for the scenarion Yverdon – Laufenburg. Receiver antenna height = 8 m, transmitter antenna
height = 10 m, propagation time probability = 50%
Attachment 3
to Annex 11
Radiated Power for Co-adjacent and spurious domain
The values calculated in Tables A11.2, A11.3 and A11.4 are based on emission power densities
shown in Figs A11.3, A11.4 and A11.5.
0 20 40 60 80 100 120 14060
80
100
120
140
160
distance [km]
loss [
dB
]
0 20 40 60 80 100 120 140400
600
800
1000
1200
1400
distance [km]
pro
file
heig
ht
[m]
110 Rep. ITU-R M.2478-0
TABLE A11.2
Bandwidth-corrected co – channel, adjacent channel and spurious domain interference from
a SSB amateur radio transmitter to a mobile receiver with 16 kHz Bandwidth
Interference emissions Power PE e.i.r.p. for mask
Option 1 (dBm)
Power PE e.i.r.p. for mask Option
2 (dBm)
Same channel 50 dBm + 9.4 dBi
= 59.4 dBm
50 dBm + 9.4 dBi
= 59.4 dBm
1st adjacent channel
BWRX = 16 kHz
–35.8 dBm/kHz + 10log(16)
= –23.8 dBm
–35.8 dBm/kHz + 10log(16)
= –23.8 dBm
2nd adjacent channel
BWRX = 16 kHz
–35.8 dBm/kHz + 10log(16)
= –23.8 dBm
–35.8 dBm/kHz + 10log(16)
= –23.8 dBm
Spurious -(43 dBc + 17 dBW) =
–60 dB
Measurement BW = 100 kHz
BWRX = 16 kHz
–35.8 dBm/kHz + 10log(16)
= –23.8 dBm
–35.8 dBm/kHz + 10log(16)
= –23.8 dBm
TABLE A11.3
Bandwidth-corrected co – channel, adjacent channel and spurious domain interference from
a wideband amateur radio transmitter to a mobile receiver with 16 kHz Bandwidth
Interference emissions Power PE e.i.r.p. for mask option 1
(dBm)
Power PE e.i.r.p. for mask option 2
(dBm)
Same channel 26.2 dBm/kHz + 10log(16)
= 38.2 dBm
26.2 dBm/kHz + 10log(16)
= 38.2 dBm
1st adjacent channel 26.2 dBm/kHz + 10log(16)
= 38.2 dBm
26.2 dBm/kHz + 10log(16)
= 38.2 dBm
2nd – 6th channel 26.2 dBm/kHz + 10log(16)
= 38.2 dBm
26.2 dBm/kHz + 10log(16)
= 38.2 dBm
7th – 12th channel 16.2 dBm/kHz + 10log(16) = 28.2 dBm 1.2 dBm/kHz + 10log(16) = 13.2 dBm
Spurious 16th – 30th
channel
–48.8 dBm/kHz + 10log(16 kHz)
= –36.8 dBm
–48.8 dBm/kHz + 10log(16 kHz)
= –36.8 dBm
Rep. ITU-R M.2478-0 111
TABLE A11.4
Bandwidth-corrected co – channel, adjacent channel and spurious domain interference from
a FM amateur radio transmitter to a mobile receiver with 16 kHz Bandwidth
Interference emissions Power PE e.i.r.p. for mask Option 1
(dBm)
Power PE e.i.r.p. for mask Option 2
(dBm)
Same channel 43 dBm + 2.5 dBi
= 45.5 dBm
43 dBm + 2.5 dBi
= 45.5 dBm
1st adjacent channel
BWRX = 16 kHz
23.5 dBm/kHz + 10*log(2.2)
= 26.9 dBm
8.5 dBm/kHz + 10*log(2.2)
= 11.9 dBm
2nd adjacent channel
BWRX = 16 kHz
–56.6/kHz + 10(16)
= –44.6 dBm
–56.6 dBm/kHz + 10(16)
= –44.6 dBm
Spurious 60 dB
BWRX = 16 kHz
–56.6 dBm/kHz + 10log(16)
=-44.6 dBm
–56.6 dBm/kHz + 10log(16)
= –44.6 dBm
Attachment 4
to Annex 11
Minimum required path loss
The values for the minimum required path loss for co- and adjacent channel scenarios considering
the different type of amateur applications are shown in Tables A11.5, A11.6 and A11.7.
TABLE A11.5
Minimum path loss necessary to protect the mobile radio receiver from
amateur service wideband transmitter interference
Interference scenario Necessary path loss AS1 for mask
Option 1 (dB)
Necessary path loss AS2 for mask
Option 2 (dB)
Same channel – 6th channel 38.2 dBm + 121.8 dBm = 160 dB 38.2 dBm + 121.8 dBm = 160 dB
7th – 12th channel 28.2 dBm + 121.8 dBm = 150 dB 13.2 dBm + 121.8 dBm = 135 dB
16th – 30th channel –36.8 dBm + 121.8 dBm = 85 dB –36.8 dBm + 121.8 dBm = 85 dB
112 Rep. ITU-R M.2478-0
TABLE A11.6
Minimum path loss necessary to protect the mobile radio receiver from
amateur service SSB transmitter interference
Interference scenario Necessary path loss AS1 for mask
Option 1 (dB)
Necessary path loss AS2 for mask
Option 2 (dB)
Same channel 59.4 dBm + 121.8 dBm – 3 dB
= 178.2 dB
59.4 dBm + 121.8 dBm – 3 dB
= 178.2 dB
1st adjacent channel –23.8 dBm + 121.8 dBm = 98 dB –23.8 dBm + 121.8 dBm = 98 dB
2nd adjacent channel –23.8 dBm + 121.8 dBm = 98 dB –23.8 dBm + 121.8 dBm = 98 dB
Spurious –23.8 dBm + 121.8 dBm = 98 dB –23.8 dBm + 121.8 dBm = 98 dB
TABLE A11.7
Minimum path loss necessary to protect the mobile radio receiver from
amateur service FM transmitter interference
Interference scenario Necessary path loss AS1 for mask
Option 1 (dB)
Necessary path loss AS2 for mask
Option 2 (dB)
Same channel 45.5 dBm + 121.8 dBm = 167.3 dB = 45.5 dBm + 121.8 dB = 167.3 dB
1st adjacent channel 26.9 dBm + 121.8 dB = 148.7 dB 11.9 dBm + 121.8 dB = 133.6 dB
2nd adjacent channel –44.6 dBm + 121.8 dB = 77.2 dB –44.6 dBm + 121.8 dB = 77.2 dB
Spurious –44.6 dBm + 121.8 dB = 77.2 dB –44.6 dBm + 121.8 dB = 77.2 dB
Annex 12
Radio Interference coverage mapping
This annex considers plotting the interference created by an amateur station on a real geographic map
in order to better visualise and interpret the propagation phenomena. To do so, we place an amateur
station in a given geographical location, and then compute the amount of interference created by this
station in the adjacent geographical location area.
Maximum allowed emission powers, and maximum antenna gains are taken into account for amateur
stations. The antenna patterns are considered to be omnidirectional in order to evaluate the impact in
all the direction. Regarding the mobile (victim), only the base station is considered as it has the
maximum antenna gain and the higher height.
A propagation probability Tpc = 50% is considered, indicating that during 50% of time the
interference level could be higher than the evaluated ones. As stated in § 2.3, this represents somehow
an optimistic interference scenario. Even with this optimistic value, in the results section it will be
observed that large areas are interfered, this will obviously be worsen with a Tpc = 10%.
Note that only co-channel operation is taken into account. The maximum level of interference
computed in § A11.3 remains valid for this section.
Rep. ITU-R M.2478-0 113
Below are summarized the parameters that are used for the production of radio interference coverage
maps:
– SSB mode: Emission power = 50 dBm, Antenna gain = 9.4 dBi, Antenna height = 10 m,
omnidirectional, polarization horizontal, bandwidth = 3 kHz;
– FM mode: Emission power = 43 dBm, Antenna gain = 2.5 dBi, Antenna height = 10 m,
omnidirectional, polarization vertical, bandwidth = 16 kHz;
– Wideband Digital: Emission power = 47 dBm, Antenna gain = 4 dBi, Antenna height = 10 m,
omnidirectional, polarization vertical, bandwidth = 300 kHz;
– Mobile Base Station: omnidirectional, Antenna height = 8 m, bandwidth = 16 kHz.
A12.1 Determination of the interference level
The interference level created by the amateur station is computed each 0.02° point in
latitude/longitude, using the same approach described in § 3.3, i.e.:
𝐼 = 𝑃𝐴𝑚𝑎𝑡 + 𝐺𝐴𝑚𝑎𝑡 + 𝐵𝑤𝐶𝑜𝑟𝑟𝑒𝑐𝑡𝑖𝑜𝑛 − 𝐿𝑃𝑟𝑜𝑝𝑔𝑎𝑡𝑎𝑖𝑜𝑛 − 𝑃𝑜𝑙𝑚𝑖𝑠 dBm
where 𝐿𝑃𝑟𝑜𝑝𝑔𝑎𝑡𝑎𝑖𝑜𝑛 is the propagation loss computed using Recommendation ITU-R P.2001-2, and
the numerical terrain profile SRTM (Shuttle Radar Topography Mission, 90 metres resolution,
provided by NASA8).
Because the ambient noise figure is higher than the receiver noise figure, the gain of the receiving
antenna is not taken into account.
A12.2 Simulation results
Simulations were conducted for different terrain nature in order to observe and to appreciate the
different propagation phenomena, namely:
– Yverdon-Les-Bains (Switzerland, Latitude: 46.7833° Longitude: 6.65°);
– Aachen (Germany, Latitude: 50.77664°, Longitude: 6.08342°);
– Faux d’Enson (Switzerland, Latitude: 47.363056°, Longitude: 6.958889°).
– Vallon-En-Sully (France, Latitude: 46.5333°, Longitude: 2.6°).
For each coverage map, a colour map level is always depicted near the figures. The unit of the colour
map is in dBm. All levels in red are the ones with received interfering power higher than
–60 dBm. Geographical areas not coloured are the areas where the received interfering power is less
than the maximum acceptable interfering power (–121.8 dBm). Please note that due to the symmetry
of Recommendation ITU-R P.2001 the propagation model, an interfered point would at it turn create
interference to the transmitter point if the roles would be inverted.
A12.3 Results for Yverdon-Les-Bains Switzerland
Results for Yverdon-Les-Bains are depicted in Figs A12.1, A12.2 and A12.3.
For the SSB mode, we can observe that areas situated, on average, at 240 km can be interfered. In
some cases, given the terrain profile, and due to occurrence of some propagation phenomena, this
distance can achieve more than 350 km as depicted before in the MCL studies.
In Fig. A12.4, we depicted the terrain profile from Yverdon (Switzerland) to Milan (Italy). In the SSB
mode, Milan is one of the interfered cities, when considering Fig. 4, with this scenario ti can be
8 https://www2.jpl.nasa.gov/srtm/.
114 Rep. ITU-R M.2478-0
checked that different types of propagation phenomena like spherical diffraction line of sight but also
Bullington diffraction intervene with different weights.
The separation distances are smaller for the FM Mode and the Wideband Digital mode: they are of
200 km on average for FM mode and less than that for the Wideband digital. This is mainly first due
to the fact that the e.i.r.p. values are lower than for SSB mode. More than that, for the wideband
digital mode, the bandwidth factor cuts the power seen by the smaller bandwidth of the Mobile Base
Station. Once again the obtained distances match the one computed in the MCL assessment
previously presented in this Annex. However, even if smaller distances are achieved with the
Wideband Digital Mode, one should note that it creates interference on large portion of the frequency
spectrum dedicated to the Mobile, as already explained in the MCL section.
FIGURE A12.1
Interference caused by an amateur station located at Yverdon (Switzerland) emitting with SSB mode on a Mobile Base
station. Coloured areas are the interfered areas
Rep. ITU-R M.2478-0 115
FIGURE A12.2
Interference caused by an amateur station located at Yverdon (Switzerland) emitting with FM mode on a Mobile Base
station. Coloured areas are the interfered areas
FIGURE A12.3
Interference caused by an amateur station located at Yverdon (Switzerland) emitting with Wideband digital mode on a
Mobile Base station. Coloured areas are the interfered areas
116 Rep. ITU-R M.2478-0
FIGURE A12.4
Path from Yverdon to Milan, Top: Different path losses for Tpc = 50%,
Bottom: Path profile, Polarization Horizontal
A12.4 Results for Aachen (Germany)
Results for Aachen (Germany) are depicted in Figs A12.5, A12.6 and A12.7.
In this scenario, the city of Aachen is at about 260 m Altitude where in the neighbouring area studied,
the maximum altitude encountered is around Willingen with more than 700 m altitude. The variation
in the path profile does not depict a large fluctuation.
For SSB mode, only part of Germany and the Netherlands are interfered, while the whole Belgium
and Luxembourg suffer from interference. The North east border of France is also touched. Maximum
separation distance can achieve 270 km.
In this case, it can be clearly observed that the interfered areas shrunken for the FM and Wideband
digital modes. The maximum required distances are about 190 km (Amsterdam) for the FM mode
and 160 km for Wideband Digital mode (Oud-Beijerland).
Rep. ITU-R M.2478-0 117
FIGURE A12.5
Interference caused by an amateur station located at Aachen (Germany) emitting with SSB mode.
Coloured areas are the interfered area
FIGURE A12.6
Interference caused by an amateur station located at Aachen Germany emitting with FM mode.
Coloured areas are the interfered area
118 Rep. ITU-R M.2478-0
FIGURE A12.7
Interference caused by an amateur station located at Aachen (Germany) emitting with Wideband digital mode. Coloured
area are the interfered area
A12.5 Results for Faux d’Enson (Swiss/French border)
Results for Faux d’Enson (Swiss/French border) are depicted in Figs A12.8, A12.9 and A12.10.
Faux d’Enson is at 927 m altitude, such altitude allows it to have a wide radio coverage. For instance,
using SSB mode, an amateur station could interfere up to Paris (380 km far), with severe levels of
interference up to 150 km around. Parts of France, Switzerland, Germany Luxembourg, Liechtenstein
and Austria are interfered.
Again, for FM and wideband digital these areas are shrunken as depicted in the Figures below.
For convenience of the reader and for understanding the different phenomena, in Fig. A12.11 is
plotted the path profile from Faux d’Enson to Paris and the different propagation losses.
Rep. ITU-R M.2478-0 119
FIGURE A12.8
Interference caused by an amateur station located at Faux d’Enson (Swiss/French border) emitting with SSB mode. Coloured
areas are the interfered area
FIGURE A12.9
Interference caused by an amateur station located Faux d’Enson (Swiss/French border) emitting with FM mode. Coloured
areas are the interfered area
120 Rep. ITU-R M.2478-0
FIGURE A12.10
Interference caused by an amateur station located at Faux d’Enson (Swiss/French border) emitting with Wideband digital
mode. Coloured area are the interfered area
FIGURE A12.11
Faux d'Enson to Paris path. Top: Different propagation losses, bottom: path profile
Rep. ITU-R M.2478-0 121
A12.6 Results for Vallon-En-Sully (France)
The final area studied in this Annex is cantered in Vallon-En-Sully in the centre of France. Vallon-
En-Sully is at 208 m altitude. For the SSB mode, we can observe that interference up to 300 km can
be encountered up to Paris. Again, for FM mode this interference range is shrunken to 200 km and to
140 km. Being in the centre of the country, only interference in France is encountered.
FIGURE A12.12
Interference caused by an amateur station located at Vallon En Sully (France) emitting with SSB mode.
Colored areas are the interfered area
122 Rep. ITU-R M.2478-0
FIGURE A12.13
Interference caused by an amateur station located at Vallon En Sully (France) emitting with FM mode. Colored areas are the
interfered area
FIGURE A12.14
Interference caused by an amateur station located at Vallon En Sully (France) emitting with WBD mode. Colored areas are
the interfered area
Rep. ITU-R M.2478-0 123
Annex 13
Amateur service vs. Mobile service Monte-Carlo study details
The Monte-Carlo approach used in this annex consists in localising a mobile station in a given area
with a fixed operational frequency, and then spread a certain number of amateurs station around it.
Those amateurs are scattered within a certain range according to propagation effects and attributed
different frequency channels (thus different incident power to the victim) and different azimuths. The
aggregated interference to the mobile is than computed. This process is repeated a certain number of
times and a cumulative distribution function is deduced.
A13.1 Determination of the interference level
The interference level created by the amateur stations surrounding the mobile is computed according
to the following equation:
𝐼 = 10 ∗ log10(∑ 10𝑃𝐴𝑚𝑎,𝑖+𝐺𝐴𝑚𝑎,𝑖+𝐵𝑤𝐶𝑜𝑟𝑟𝑒𝑐𝑡𝑖𝑜𝑛−𝐿𝑃𝑟𝑜𝑝,𝑖−𝑃𝑜𝑙𝑚𝑖𝑠𝑁𝐴𝑚𝑎𝑖=1 ) dBm (1)
where:
𝑁𝐴𝑚𝑎: total number of amateur station surrounding the mobile victim
𝑃𝐴𝑚𝑎,𝑖: is the emission power of the ith amateur station, in dBm
𝐺𝐴𝑚𝑎,𝑖: ith amateur station antenna gain, in the direction of the mobile station in dBi
𝐵𝑊𝐶𝑜𝑟𝑟: correction factor for calculation of power density, due to the fact that interferer
and victim operate with a different signal bandwidth, it applies only if the
interferer bandwidth is greater than the victim bandwidth 𝐵𝑊𝐶𝑜𝑟𝑟 = 10 ∗log (BWMob/BWAmat), in dB
𝑃𝑜𝑙𝑚𝑖𝑠: polarization mismatch considered to be 3 dB for the SSB mode and 0 dB for FM
and wideband modes
𝐿𝑃𝑟𝑜𝑝,𝑖: propagation Loss from the ith amateur station to the mobile victim, in dB.
Because the ambient noise figure is higher than the receiver noise figure, the gain of the receiving
antenna is not taken into account.
A13.2 Amateur service characteristics
The amateur service transmitter parameters are extracted from Table 9 of this Report.
A13.3 Propagation Model
Radio wave propagation is calculated according to the model of Recommendation ITU-R P.2001-2.
No clutter loss is considered. As stated in Recommendation ITU-R P.2001-2, section 1.1, the model
is believed to be most accurate for distances from about 3 km to 1000 km. At shorter distances, the
effect of clutter will tend to dominate unless the antenna heights are high enough to give an
unobstructed path. It can be seen later, that the interference ranges are often significantly longer than
3 km. The antennas heights are 8 m or more for all type of amateur radio stations and for the base
station victim receiver. The considered radio stations often operate in rural environment, where the
clutter height can be assumed to be below 8 m.
124 Rep. ITU-R M.2478-0
Regarding the terrain profile, our simulations are based on and the numerical terrain profile SRTM
(Shuttle Radar Topography Mission, 90 meters resolution, provided by NASA9). Note that the terrain
profile is deduced for each path between each amateur station and the victim mobile station.
Note that the percentage of time used in the simulations is not fixed, but randomly chosen from
1-99%, since dealing with a Monte Carlo simulation, and that the amateur see the mobile in different
propagation conditions.
A13.4 Protection criterion and ambient noise figure
For mobile radios, a protection criterion of I/N = – 6 dB is specified. According to Recommendation
ITU-R P.372-13 and ITU-R M.1808, natural background noise (dominated by galactic noise)
corresponds to a noise figure of F = 15 dB at a frequency of 50 MHz. The maximum acceptable
interference power for the mobile Service 𝑃𝑝𝑟𝑜𝑡𝑒𝑐𝑡,is calculated as follows:
𝑃𝑝𝑟𝑜𝑡𝑒𝑐𝑡 = 𝑁0 + 𝐹𝑠 + 10 log(𝐵𝑊) − 𝐼
𝑁
where 𝑁0 is the thermal noise power at a temperature of 20°C, BW is the receiver bandwidth and Fs
= 16.2 dB is the noise figure of the added ambient noise and receiver noise.
Accordingly, the maximum acceptable interference power for mobile service application is calculated
as follows:
−𝟏𝟐𝟏. 𝟖 𝒅𝑩𝒎 = −174𝑑𝐵𝑚
𝐻𝑧+ 16.2𝑑𝐵 + 10log (16 𝑘𝐻𝑧) − 6 𝑑𝐵
The values for the ambient noise figure F defined in Recommendation ITU-R P.372-13 relate to
measurements with a vertical dipole or monopole antenna. In the given case, the victim antennas
(mobile service) also show isotropic directivity in the azimuth, though with a gain which differs from
the Recommendation's notional ideal antennas. However, because the ambient interference is
substantially higher than the level of the receiver's internal noise, the gain of the victim antenna needs
not be considered for calculation of ambient noise.
It should also be noted that the assumed ambient noise figure of 15 dB for antennas with increased
directivity in the horizontal direction has been set somewhat too high. If corresponding antennas (with
increased directivity in the elevation) are used at the victim receiver, the computed interference ranges
represent a minimum, as in this case galactic noise actually reduces receiver sensitivity by less than
the determined 16.2 dB.
A13.5 Amateurs Emission masks/Mobile reception mask
Amateurs masks are designed as per Recommendations ITU-R SM.1541-6 Annex 9, ITU-R SM.329-
12 and ETSI EN 301 783. A second option (option 2) is also studied by adding 15 dB attenuation for
the first floor OoB emission.
The Mobile reception mask is considered to be perfect (rejecting all interference coming out of the
16 kHz mobile bandwidth).
A13.6 SSB Case
According the IARU frequency plan for the 50-52 MHz band, the SSB operating range is
50.105-50.250 MHz. The following algorithm is adopted:
9 https://www2.jpl.nasa.gov/srtm/.
Rep. ITU-R M.2478-0 125
A13.6.1 Proposed algorithm and used parameters
– Step 1: Attribute a fixed operating frequency to the mobile (victim), in our simulation
the centre frequency of SSB range is used, namely, f_m = 50.1783 MHz. This frequency will
be fix all over the Monte-Carlo runs.
– Step 2: Localise the mobile, in our simulations Vallon-En-Sully in France (46.5333°, 2.6°)
has been chosen. This localisation is fixe all over the Monte-Carlo runs.
– Step 3: Precise the area of simulation, carry out coverage simulation to determine the
geographical area from where amateurs could create potential interference to the mobile.
Using google map measurement tool, insert a circle cantered at the mobile position which
could cover the largest possible interference area, than, deduce its radius. For Vallon-En-
Sully example, a circle of 200 km can be inserted in the interference area. The simulation
will be carried out inside this 200 km circle.
FIGURE A13.1
Simulation area for a mobile centered in Vallon-En-Sully, SSB case (red circle)
– Step 4: Deduce the number of active channels (busy channels) this area, this is the
number of active amateur without channel redundancy. It is computed thanks to the algorithm
described in § 3.7 of this Report. When using a radius of 200 km for the SSB mode, it is
found that 19 amateurs are active within this area.
126 Rep. ITU-R M.2478-0
FIGURE A13.2
Number of active amateurs within 200 km using SSB mode
– Step 5: Scatter randomly 19 amateurs stations inside the circle of 200 km.
FIGURE A13.3
Example of one shot scattering of 19 amateurs (circles) around one mobile
station (diamond) inside a circle of 200 km
– Step 6: Attribute to each amateur a frequency channel. To do so it is required to create a
frequency plan for the SSB channel. In the band 50.105-50.250 MHz, we need to center
channels each 3 kHz. Meaning: (50.1065 50.1095 50.1125 50.1155 50.1185 50.1215
50.1245 …).
Than choose random 19 random channels from these 48 channels.
Global variables
Density of amateurs (average over all Europe) 0,073 km-2
Fraction of amateurs using the band 0,08
Session duration (hours/year) based on 2 hours a day 730
Observation window (hours/year) 8760
Fraction of time transmitting within a single session (= 0.5 if PTT considered) 0,5
SSB
Application Variables Variable Name App 1
Contact range at usable SNR 200
Fraction of amateurs using specific application who are using the band (must all add up to 1) R_App 0,6
Channel bandwidth (analog) 3
Number N/A
Calculations
Density of amateurs (average over all Europe) D_A 0,073
Cell size==service area (assuming circular area) Cell size (area) 125663,71
Fraction of amateurs using the band R_A_50_54 0,08
Session duration (hours/year) based on 2 hours a day (All time busy for repeaters, beacons
and infrastructure) T_session 730
Fraction of time transmitting within a single session F_activity 0,5
Observation window (hours/year) W 8760
Number of amateurs or transmitters per km2 per application 0,003504
Number of amateurs in cell using specific application Nb_Amateur_Cell 440,32563
Spectrum required within cell for application - not averaged over time BW_app 1320,9769
Bandwidth occupied as function of time for application Occup_BW_app 55,040703
Number of integer channels required (i.e. Occup_BW_app/Channel Bandwidth) 19
Rep. ITU-R M.2478-0 127
FIGURE A13.4
Random attribution among the 48 channels
– Step 7: Attribute to each amateur a random azimuth (from the north); the amateur
antenna used in the simulation is the one depicted in Fig. A13.1.
– Step 8: Compute the aggregate interference to the mobile according to equation (1).
– Step 9: Get back to Step 5 and repeat the process 10 000 times.
– Step 10: Create the CDF of all stored interference in dBm.
A13.6.2 Simulation results for SSB
The obtained simulation results for the SSB case are depicted in Fig. A13.5 (Option 1). The protection
criterion of –121.8 dBm is exceeded for 86.5% of the time for the option 1 mask, and 86.16% of the
time for option 2 mask.
FIGURE A13.5
Inverse cumulative CDF for the SSB case
In order to assess the impact of the number of amateurs on the interference created to the mobile, we
carried out a bunch of simulation when varying the number of active amateurs within the vicinity of
the mobile. The results are depicted in Figure 13.6. It can be logically observed that amount of
interference reduces according to the number of active amateur stations. For 14 amateurs the
probability of interference is of 75.45%, for 10 users it is 62.77%, 38.18% for 5 users, 17.21% for 2
user and only 8.49% for one user.
Ch1 Ch2 Ch3 Ch4 Ch5 Ch6 Ch7 … Ch44 Ch45 Ch46 Ch47 Ch48
128 Rep. ITU-R M.2478-0
FIGURE A13.6
Impact of the amateur number on the interference under mask Option 2
It is also considered a scenario where a protection distance was imposed on the amateurs. This
protection distance is centered at the mobile position. In that case the amateurs are scattered inside a
crown delimited by the protection distance diameter and the simulation radius diameter.
FIGURE A13.7
Example of amateurs scattering when considering a protection distance of 90 km
Rep. ITU-R M.2478-0 129
One should note that the application of a separation distance could be very difficult given that the
land mobile has to operate in unknown places without notice. Table A13.1 depicts a summary of the
obtained results.
TABLE A13.1
Summary of the interference probability for different users and different considered
protection distances, Option mask 2
Number of users inside 200 km circle area
1 2 5 10 14 19
Pro
tect
ion
dis
tan
ce None 8.49% 17.21% 38.18% 62.77% 75.45% 86.5%
10 7.46% 14.35% 31.99% 55.04% 68.47% 80.2%
30 6.35% 11.58% 26.77% 47.78% 61.62% 73.73%
50 5.06% 9.05% 22.86% 41.76% 53.84% 65.82%
70 4.1% 8.57% 19.36% 36.75% 48.12% 58.94%
90 3.59% 6.77% 16.6% 31.56% 42.58% 52.8%
100 3.54% 6.57% 15.33% 29.10% 40.28% 51.1%
A13.7 FM case
According the IARU frequency band plan for the 50-52 MHz band, the FM operating range is
51.210-51.390 MHz.
A13.7.1 Proposed algorithm and used parameters
The same algorithm adopted for the SSB case is used for the FM, except that:
– The Mobile is still localized in Vallon En Sully; its centre frequency is f_m = 51.3 MHz.
– Regarding the simulation area, coverage processing shows that a circle of 120 km is required
for the FM case. Please note that distance is not inherent to the amateur contact range
distance, which depends only on the amateurs’ characteristics and the propagation conditions.
The simulation radius depends on the amateur’s emission characteristics, but also on the land
mobile reception characteristics and of course, on the propagation conditions.
130 Rep. ITU-R M.2478-0
FIGURE A13.8
Simulation area for the FM case (red circle)
– According to doc PTD(18)017, only one amateur is active within this area.
– A discrete frequency plan for amateurs is created within the 51.210-51.390 MHz band,
namely 7 channels centred at (51.2225 51.2475 51.2725 51.2975 51.3225 51.3475
51.3725).
– The amateur antenna is an omnidirectional antenna with 2.5 dBi gain.
A13.7.2 Simulation results
The obtained simulation results for the FM case are depicted in Fig. A13.9 (Options 1 and 2). The
protection criterion of –121.8 dBm is exceeded for 37.25% of the time for the Option 1 mask, and
28.31% of the time for Option 2 mask.
Rep. ITU-R M.2478-0 131
FIGURE A13.9
Inverse cumulative CDF for the FM case, for both Options mask 1 and 2
Simulations were also carried-out when applying a varying protection distance. The inverse CDF of
the received interference is depicted in Fig. A13.10. The corresponding probabilities to exceed the
interference threshold are summarized in Table 5.
FIGURE A13.10
Inverse CDF of the received interference for different protection distances, FM case, Option mask 2
132 Rep. ITU-R M.2478-0
TABLE A13.2
Probability of interference according to the applied protection distance, FM case, mask
Option 2, only one amateur is active within the 120 km circle area
Protection distance (km) None 10 30 50 70 90
Probability of interference 28.31% 23.7% 16.54% 13.53% 11.35% 9.85%
In Table A13.3, a case is considered where the simulation radius is reduced to 70 km. This distance
corresponds to the communication range given by the amateurs for the FM mode. Please note again,
that this distance is different from the interference range.
TABLE A13.3
Probability of interference according to the applied protection distance, FM case, mask
Option 2, only one amateur is active within the 70 km circle area
Protection distance (km) None 10 30 50
Probability of interference 37.57% 30.08% 22.9% 17.68%
A13.8 Wideband Digital
A13.8.1 Considered scenario
In this case, a simulation area of 70 km is considered (see Fig. A13.11), as provided by the
interference coverage simulation. In the absence of the antenna pattern for the 4 dBi directional
antenna, a 2.5 dBi omni-directional antenna is used.
The simulation scenario in this case is different from the two previous ones. One amateur station
active in the 70 km circle area is considered, then the probability of interference created into the
mobile station is computed, in the case where the mobile station is active within a channel situated in
band, 1st floor OoB, 2nd floor OoB, 3rd floor OoB or Spurious domain of the amateur emission.
Rep. ITU-R M.2478-0 133
FIGURE A13.11
Simulation area for the WB digital case (red circle)
A13.8.2 Simulation results
The obtained results are summarized in Table A13.4.
Table A13.4
Simulation results for the WB digital case
Inband up to
10th channel
1st floor OoB 11th to
20th channel,
M1|M2
2nd floor OoB 21th to
25th channel
3rd floor OoB 26th to
50th channel Spurious
None 93.65% 78.90%|50.13% 10.81% 3.15% 0.85%
10 km 91.14% 73.15%|37.45% 0.40% 0.01% 0%
30 km 86.37% 55.98%|11.85% 0.04% 0% 0%
50 km 75.92% 38.80%|2.72% 0.01% 0% 0%
134 Rep. ITU-R M.2478-0
Annex 14
Sharing with the radiolocation service (WPR)
A14.1 Background
In the frequency band 46-68 MHz, RR No. 5.162A provides an additional allocation to the
radiolocation service on a secondary basis in a number of countries and limited to the use of wind
profiler radars.
5.162A Additional allocation: in Germany, Austria, Belgium, Bosnia and Herzegovina,
China, Vatican, Denmark, Spain, Estonia, the Russian Federation, Finland, France, Ireland,
Iceland, Italy, Latvia, The Former Yugoslav Republic of Macedonia, Liechtenstein,
Lithuania, Luxembourg, Monaco, Montenegro, Norway, the Netherlands, Poland, Portugal,
the Czech Rep., the United Kingdom, Serbia, Slovenia, Sweden and Switzerland the band
46-68 MHz is also allocated to the radiolocation service on a secondary basis. This use is
limited to the operation of wind profiler radars in accordance with Resolution 217
(WRC-97). (WRC-12)
The relevant Wind profiler radars parameters for sharing studies with amateur service are described
in Table A14.1.
TABLE A14.1
System parameter Range of values
Pulse peak power (kW) 5 – 60
Average transmitted power (kW) 0.5 – 5
Main beam antenna gain (dBi) 30 – 34
Antenna beamwidth (degree) 4 – 6
Main pointing elevation angle (degree) 90 (zenith)
Tilt angle from main pointing (degree) 11 – 16
Antenna side-lobe suppression between 0 and 5° compared to horizon (dB) 33 (minimum) – 40 (Median)
Antenna height (m) 1
Pulse width (µs) 1 – 10
Necessary bandwidth (MHz) 0.2 – 2.2
Occupied bandwidth (MHz) 0.5 – 5
Protection criteria (I/N)(dB) –6
Noise figure (dB) 3
Maximum interference level in necessary bandwidth (dBW) –154 (for 0.2 MHz
bandwidth)
–144 (for 2 MHz bandwidth)
Rep. ITU-R M.2478-0 135
A14.2 WPR location and parameters
FIGURE A14.1
Identified VHF WPR systems in Europe (red = in 50-54 MHz, green = out of band)
TABLE A14.2
WPR locations parameters
Sitename WMO Site
No
Latitude
, N
Longitude
, E
Freq.
(MHz)
Power
mean
(kW)
Power Pk
(kW)
Antenna
gain
Beam
width
Avg
mins
Kühlungsborn (OSWIN)
(Germany)
54.1183 11.7690 53.50 4.5 90.0 30.0 6.0
South Uist (UK) 03019, 03020,
03021, 03022
57.3536 –7.3752 64.00 4 .0 40.0 29.0 4.5 15/30
Abersywyth (NERC-
MST) (UK)
3501 52.4245 –4.0055 46.50 2.5 100 (typ.)
160.0
(max.)
35 .0 3.0 30
Clermont-Ferrand
(France)
7453 45.7125 3.0903 45.00 0.8 5.0 30.0 5.5
Lannemezan (France) 7626 43.1290 0.3660 45.00 0.8 5.0 30.0 5.5 15
Kiruna (Esrange)
(Sweden)
2043 67.8865 21.1065 52.00 72.0 29.0 6.7 30
Andenes MAARSY-
MST (Norway)
1012 69.2980 16.0420 53.50 40.0 800.0 33.5 3.6
SOUSY Svalbard Radar
(Norway)
78.1530 16.0300 53.50 0.2 2.0 30.0 5
Rome (Ciampino) (Italy) 16239 41.8080 12.5850 65.50 ? ? ?
136 Rep. ITU-R M.2478-0
TABLE A14.3
WPR parameters used for study
System parameter Range of values
Pulse peak power (kW) 2 – 800
Average transmitted power (kW) 0.2 – 72
Main beam antenna gain (dBi) 29 – 35
Antenna beamwidth (degrees) 3 – 7
Main pointing elevation angle (degrees) 90 (zenith)
Tilt angle from main pointing (degrees) 11 – 16
Antenna side-lobe suppression between 0 and 5° compared to horizon (dB) 33 (minimum) – 40 (Median)
Pulse width (µs) 1 – 10
Necessary bandwidth (MHz) 0.2 – 2.2
Occupied bandwidth (MHz) 0.5 – 5
Protection criteria (I/N)(dB) –6
Noise figure (dB) 3
Maximum interference level in necessary bandwidth (dBW) –154 (for 0.2 MHz
bandwidth)
A14.3 In-band separation distances
At a preliminary stage, it is proposed to assess separation distance between amateur service stations
and WPR taking into account the following elements:
– Amateur service stations typical e.i.r.p. ranging 2 to 26 dBW (see ITU-R M.1732 for both
analogue and digital systems).
– Amateur service stations typical bandwidth ranging 2.7 to 16 kHz (see ITU-R M.1732 for
both analogue and digital systems).
– WPR victim scenario.
– Hata (rural) propagation model (at 52 MHz) (median case):
Rep. ITU-R M.2478-0 137
It should be noted that the case of the Amateur systems antenna height of 1 000 m is not considered
since it is not within the validity range of the E-Hata model. It should also be noted that considering
the WPR antenna height of 1 m, such 1 000 m height would lead to a visibility distance of around
115 km (hence free space).
A14.4 Separation distances
FM (F3E) case (only extreme distances are provided)
For the FM (F3E) case, the separation distances would be ranging:
– 60 to 158 km (Amateur antenna height of 10 m).
– 79 to 196 km (Amateur antenna height of 20 m).
Wideband (omni) case (only extreme distances are provided)
Amateur
Power
(dBW)
Amateur
gain (dBi)
Amateur
Bandwidth
(kHz)
Amateur
antenna
height
(m)
WPR
bandwidth
(MHz)
BW
factor
(dB)
WPR
antenna
gain (dBi)
WPR
antenna side
lobe
suppression
(dB)
Maximum
interference
level (dBW)
Required
Isolation
(dB)
Separation
distance
(km)
13 2.5 16 10 2 0 30 40 -143.96572 149.466 60
13 2.5 16 10 0.2 0 34 33 -153.96572 170.466 158
13 2.5 16 20 2 0 30 40 -143.96572 149.466 79
13 2.5 16 20 0.2 0 34 33 -153.96572 170.466 196
Amateur
Power
(dBW)
Amateur
gain (dBi)
Amateur
Bandwidth
(kHz)
Amateur
antenna
height
(m)
WPR
bandwidth
(MHz)
BW
factor
(dB)
WPR
antenna
gain (dBi)
WPR
antenna side
lobe
suppression
(dB)
Maximum
interference
level (dBW)
Required
Isolation
(dB)
Separation
distance
(km)
17 2.5 300 10 2 0 30 40 -143.96572 153.466 73
17 2.5 300 10 0.2 1.7609 34 33 -153.96572 172.705 173
17 2.5 300 20 2 0 30 40 -143.96572 153.466 95
17 2.5 300 20 0.2 1.7609 34 33 -153.96572 172.705 214
138 Rep. ITU-R M.2478-0
For the Wideband (omni) case, the separation distances would be ranging:
– 73 to 173 km (Amateur antenna height of 10 m).
– 95 to 214 km (Amateur antenna height of 20 m).
Wideband (directional) case
For the Wideband (directional) case, the separation distances would be ranging, when considering
the Amateur station main beam:
– 79 (case 1) to 184 km (case 2) (Amateur antenna height of 10 m).
– 102 (case 3) to 227 km (case 4) (Amateur antenna height of 20 m).
The following Figure provides, for the cases 1 to 4 above, the variation in separation distances vs
azimuth taking into account the Amateur system relative gain according to the antenna pattern:
Amateur
Power
(dBW)
Amateur
gain (dBi)
Amateur
Bandwidth
(kHz)
Amateur
antenna
height
(m)
WPR
bandwidth
(MHz)
BW
factor
(dB)
WPR
antenna
gain (dBi)
WPR
antenna side
lobe
suppression
(dB)
Maximum
interference
level (dBW)
Required
Isolation
(dB)
Separation
distance
(km)
17 4 300 10 2 0 30 40 -143.96572 154.966 79
17 4 300 10 0.2 1.7609 34 33 -153.96572 174.205 184
17 4 300 20 2 0 30 40 -143.96572 154.966 102
17 4 300 20 0.2 1.7609 34 33 -153.96572 174.205 227
Rep. ITU-R M.2478-0 139
SSB (J3E) (directional) case
For the SSB (J3E) (directional) case, the separation distances would be ranging, when considering
the Amateur station main beam:
– 73 (case 5) to 186 km (Amateur antenna height of 10 m and 10 dBW Power).
– 116 to 276 (case 6) km (Amateur antenna height of 10 m and 20 dBW Power).
– 173 (case 7) to above 300 km (Amateur antenna height of 100 m and 10 dBW Power).
– 246 to above 300 km (case 8) (Amateur antenna height of 100 m and 20 dBW Power).
The following Figure provides, for the cases 5 to 8 above, the variation in separation distances vs
azimuth taking into account the Amateur system relative gain according to the antenna pattern:
A14.5 Conclusions
The above calculations show that typical separation distance between Amateur service systems and
Wind profiler would range from 29 to distances above 300 km, confirming the need for specific
protection measures.
Taking into account the limited numbers of systems in or immediately adjacent to the frequency band
50-54 MHz range (and probably the expected low number of amateur systems in the vicinity of WPR
Amateur
Power
(dBW)
Amateur
gain (dBi)
Amateur
Bandwidth
(kHz)
Amateur
antenna
height
(m)
WPR
bandwidth
(MHz)
BW
factor
(dB)
WPR
antenna
gain (dBi)
WPR
antenna side
lobe
suppression
(dB)
Maximum
interference
level (dBW)
Required
Isolation
(dB)
Separation
distance
(km)
10 9.4 3 10 2 0 30 40 -143.96572 153.366 73
10 9.4 3 10 0.2 0 34 33 -153.96572 174.366 186
20 9.4 3 10 2 0 30 40 -143.96572 163.366 116
20 9.4 3 10 0.2 0 34 33 -153.96572 184.366 276
10 9.4 3 100 2 0 30 40 -143.96572 153.366 173
10 9.4 3 100 0.2 0 34 33 -153.96572 174.366 300
20 9.4 3 100 2 0 30 40 -143.96572 163.366 246
20 9.4 3 100 0.2 0 34 33 -153.96572 184.366 300
0
50
100
150
200
250
300
350
0 5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
10
0
10
5
11
0
11
5
12
0
12
5
13
0
13
5
14
0
14
5
15
0
15
5
16
0
16
5
17
0
17
5
18
0
Sep
arat
ion
idst
ance
(km
)
Azimuth (°)
Case 5 Case 6 Case 7 Case _8
140 Rep. ITU-R M.2478-0
installations), sharing could probably be considered on a case-by-case basis e.g. coordination zones
established in affected geographical areas.
It has to be noted that this approach, currently, could only be possible and efficient if amateur and
radiolocation services are of equal status within the 50-54 MHz band.
Annex 15
Spectrum needs evaluation based on spectrum monitoring
A15.1 Spectrum needs evaluation
In Document 5A/599 it is indicated that the spectrum need can be calculated for different countries
but the overall requirement should be based on at least average use, knowing that in the high
population density areas, additional spectrum would be required when emergencies, public service,
special events, contests and favorable anomalous propagation conditions occur. Therefore the
spectrum need is calculated for average and high population density areas, taking into account
everyday usage situations as well as exceptional usage situations where additional spectrum is
required. Accordingly the spectrum needs are calculated for the following usage situations.
– Situation A: Average use case, which represents situations of standard daily use and occurs
with a probability of 98% in time.
– Situation B: Where additional spectrum is required. This situation occurs e.g. during contests
and special events. It is assumed, that contests and special events do not occur during more
than 7 days a year. This corresponds to situation which occur with probability of less than
2% in time.
Both usage situations are considered in calculations for European countries with a typical as well as
with maximum amateur station density.
The spectrum needs evaluation based on the application based approach, as presented in section 3.5
of the main body text, considers different parameters which need to be defined respectively derived.
The derivation of the parameters for active amateur stations density and session duration is not
straightforward but are of central importance. For this study, they are obtained through an analysis of
IARU 2017 50 MHz contest log data together with the analysis of spectrum monitoring data as well
as application of correction factors regarding the forecasted growth of the amateur radio community
and propagation conditions. To obtain figures for future spectrum use and future conditions, the
following data and procedures are used:
– The number of active amateur stations for the Case A situation in a typical European country
is evaluated based on spectrum monitoring results obtained through a measurement campaign
which has taken place in the period of April to July 2018. It turns out, that for Case A the
spectrum occupancy is well below 1%.
– The session duration for an active amateur station in a Case A scenario is assumed to be 2h
a day in average when about 3% of the existing amateur licenses are daily accessing the band
50-52 MHz.
– The session duration for Case B is calculated based on the maximum duration of a two way
contact during the IARU 2017 50 MHz contest. Therefore the evaluated figure for the session
duration during contests may represent an overestimation.
Rep. ITU-R M.2478-0 141
– The number of active amateur station for the case B is evaluated based through an analysis
of IARU 2017 50 MHz contest log data. The spectrum monitoring results of the IARU 2018
50 MHz contest showed a lower activity than the activity of the IARU 2017 50 MHz contest
(evaluated based on contest log data). This may be caused by significantly worse propagation
conditions during the 2018 contest compared to the 2017 contest. Therefore, the monitoring
data of the IARU 2018 50 MHz contest are disregarded for the spectrum needs analysis.
When assuming a session duration as described above, it was found that the evaluated number
of active amateur stations was 68% of the existing amateur licenses.
– For the evaluation of the future need, the growth of the number for amateur licenses is linearly
extrapolated to the year 2038.
– It is shown, that the current spectrum use in the frequency band 50-52 MHz for the average,
everyday use case is very low, while during contests a strong increase of the use can be
observed, but only for narrow band modes. However, the use of the spectrum in the 50.5-52
MHz frequency band by all other modes like FM, RTTY, digital communication, etc. is
always very low. Accordingly, for the determination of future requirements, the ratios of the
case B are considered for narrowband applications, while for FM, repeaters, Infrastructure
and Wideband modes the circumstances of daily use (case A) are considered.
– It is shown, that the number of active amateur stations during the IARU 2017 50 MHz contest
was significantly higher, than during the ‘big opening’ on the 28.05.2018. Therefore no data
from this ‘big opening’ but only from the IARU 2017 50 MHz contest is considered for Case
B spectrum needs evaluation.
– Because future maximum solar activity may stimulate a more intense use of the band 50-52
MHz, the calculation for future spectrum needs considers in average 50% additional amateur
activity due to high solar activity.
– Figures for high amateur station populations are obtained based on data for average amateur
population density corrected trough linear interpolation.
A15.2 Current amateur station activity and spectrum needs for the average use case
According to the calculations in Attachment 1 to this Annex, the calculated minimum required
bandwidth for a country with an average density of amateur stations are as depicted in Table A15.1.
TABLE A15.1
Current minimum required bandwidth for average populated European country during an
average day, when only existing Amateur Radio applications are considered
Applications
Frequency
range
(MHz)
Required bandwidth for average use
case rounded up to multiple integers of
the application bandwidths
Existing applications Narrow band
and Telegraphy 50.0 – 50.5 3 kHz
FM, Repeaters,
Digital, etc. 50.5 – 52.0 25 kHz
An additional 3 kHz channel for the beacon HB9SIX operation is required.
142 Rep. ITU-R M.2478-0
When applying the formulas of the application based approach the value of the current amateur station
density, which was active during the period of the spectrum monitoring campaign, can be calculated
as shown below:
𝐴𝐷𝑆𝑀=
𝐵𝑊𝑂𝐶𝐶𝑇𝑜𝑏𝑠
𝑇𝑆𝑒𝑠𝑠𝑖𝑜𝑛𝑇𝑇𝑋𝐵𝑊𝑎𝑝𝑝𝐴𝑐𝑒𝑙𝑙𝐹𝐵𝑎𝑛𝑑𝐹𝑎𝑝𝑝
1
𝑀𝑆_𝑀
=2.57 𝑘𝐻𝑧∙8760ℎ
730ℎ∙0.5∙3𝑘𝐻𝑧∙196349.54𝑘𝑚2∙0.08∙0.6
1
0.7= 0.00311
where:
ADS_M density of amateur stations / km2 active during spectrum monitoring
BWocc bandwidth occupied as function of time for application
Tobs observation window (hours/year)
TSession session duration (hours/year) based on 2 hours a day
TTX fraction of time transmitting within a single session
BWapp channel bandwidth (analogue)
Acell cell sizeservice area (assuming circular area)
FBand fraction of amateurs using the band
Fapp fraction of amateurs using specific application who are using the band
MS_M_ minimum fraction.
When calculating the spectrum needs for current average use the following parameters are taken into
account.
– Observation window, W for SSB, and FM 8 760 h
– Observation window, W for Repeaters 8 760 h
– Session duration, Tsession for SSB, FM and WB 730 h
– Session duration, Tsession for Repeaters 8 760 h
– Fraction of time transmitting within a single session, Factivity 0.5
– Number of amateurs km2 0.002417
– Fraction of Amateurs using SSB, FM, Repeaters, 0.6, 0.05, 0.2.
When using above mentioned parameters with application based approach, the following spectrum
requirements numbers are obtained:
– SSB 3 kHz
– FM 25 kHz
– Repeaters 50 kHz.
An additional 3 kHz channel for the beacon operation may be required as explained in Attachment 1
to this Annex.
A15.3 Future spectrum needs for the average use case in a country with average amateur
license density
The future spectrum needs are calculated based on application based approach as shown in § 3.5 of
the main body text, except the parameter for the amateur station density. The parameter value for the
amateur station density used for the following calculation is based on the value applied for the
calculation of the current spectrum need, but corrected with a forecasted growth of Amateur Station
density within the following 20 years and an increase of Amateur station activity due to maximum
solar activity periods expected in the next years.
Rep. ITU-R M.2478-0 143
In 2017 there were 4 829 amateur licences, while in 2003 there were 4 501 amateur licenses counted
in Switzerland. This represents a growth of 7.3% within 14 years. Accordingly for 20 years a 10.4%
growth of amateur station density is considered to calculate the future spectrum needs.
The solar activity in 2017 is at the level of about 30% compared to the activity maximum of the past
solar activity cycle. It is assumed, that during a period with maximum solar activity the activity of
the amateur stations increases by 50% in average.
The above mentioned growth of the number of amateur stations and the increase of amateur activity
of 50% is considered in the spectrum needs calculation, by correcting the amateur station density
number according to the following method
𝐴𝐷𝑓𝑢𝑡𝑢𝑟𝑒 = 𝐴𝐷𝑆𝑀𝐺𝑛𝑏𝑠𝑡𝑎𝑡𝑖𝑜𝑛𝑠
𝐺𝑎𝑐𝑡𝑖𝑣𝑖𝑡𝑦
𝐴𝐷𝑓𝑢𝑡𝑢𝑟𝑒 = 0.00311 ∙ 1.104 ∙ 1.5 = 0.00516
where:
ADfuture_SSB forecasted density of amateur stations / km2
ADS_M density of amateur stations / km2 active during spectrum monitoring
Gnb_stations growth of the number of amateur licenses within 20 years
Gactivity increase of amateur activity due to periods of high solar activity.
When calculating the spectrum needs for current average use the following parameters are taken into
account.
– Observation window, W for SSB, FM and WB 8 760 h
– Observation window, W for Repeaters and Infrastructure 8 760 h
– Session duration, Tsession for SSB, FM and WB 730 h
– Session duration, Tsession for Repeaters and Infrastructure 8 760 h
– Fraction of time transmitting within a single session, Factivity 0.5
– Number of amateurs km2 0.004003
– Fraction of Amateurs using SSB, FM, WB, Repeaters, Infrastr. 0.6, 0.05, 0.05, 0.2, 0.1.
When using the above mentioned parameters with application based approach, the following
spectrum requirements numbers are obtained for Switzerland when considering the future amateur
service applications “wide band mode” and “infrastructure”:
– SSB 9 kHz
– FM 25 kHz
– Repeaters 100 kHz
– Wide band modes 500 kHz
– Infrastructure 500 kHz.
An additional 3 kHz channel for the beacon operation may be required as shown in Attachment 1 to
this Annex.
It can be concluded, that the available spectrum in Switzerland in the Frequency band 50 – 52 MHz
would also not be saturated in future when wide band mode operation is taken into account and when
average use cases are considered. It may be concluded, that the situation may be very similar in other
European countries, where the Amateur Service has assignments in the 50 – 52 MHz frequency range.
144 Rep. ITU-R M.2478-0
A15.4 Current amateur station activity and spectrum needs during a SSB contest in a country
with average amateur license density
In Switzerland the density of amateur stations in the year 2017 is 0.117 licenses per km2 as calculated
below. This number is well above the European average.
𝐴𝐷2017 = 𝑛𝑏_𝑙𝑖𝑐𝑒𝑛𝑐𝑒𝑠
𝐴𝑆𝑤𝑖𝑡𝑧𝑒𝑟𝑙𝑎𝑛𝑑=
4829
41285= 0.117
𝑙𝑖𝑐𝑒𝑛𝑐𝑒𝑠
𝑘𝑚2
where
AD2017 density of amateur licenses / km2 in Switzerland in the year 2017
Nb_license number of amateur licenses in Switzerland in the year 2017
ASwitzerland area of Switzerland.
To analyse a situation, where additional spectrum is required, statistics of the 2017 IARU 50 MHz
contest are analysed to obtain amateur station density parameter values for the spectrum needs
calculation. Information provided by IARU show that during the contest 147 different stations were
identified as operating from Switzerland. In IARU contest log statistics the number of two way
contacts per hour are analysed. During high activity periods, more than 80 two way contacts are
counted per hour. Accordingly it can be concluded that during the contest, a single two – way –
contact takes not more than 45 seconds (single session duration). In assuming an average session
duration of 45 seconds, a large margin is considered. This is also confirmed by the measurement
results of the four month spectrum monitoring campaign. There were 54’709 two way contacts from
Swiss stations within a period of a single day. Accordingly the average number of contacts per Swiss
amateur station is 372. The total session duration during the contest is 372 * 45 seconds = 4.65 hours.
When assuming that there were 10 Swiss stations participating to the contest, but were not logged at
all in the contest, then the total number of Swiss stations is assumed to be 157. Therefore, the number
of amateur stations or transmitters per km2 per SSB application is 0.0038 amateur stations or
transmitters per km2 per application corresponding to a density of active licenses of 0.0794 stations /
km2 as calculations show below.
𝐴𝐷𝑘𝑚2,𝑎𝑝𝑝_𝑆𝑆𝐵_𝑐𝑜𝑛𝑡𝑒𝑠𝑡 = 157 𝑠𝑡𝑎𝑡𝑖𝑜𝑛𝑠
41285 𝑘𝑚2 = 0.00380𝑠𝑡𝑎𝑡𝑖𝑜𝑛𝑠
𝑘𝑚2,𝑎𝑝𝑝
𝐴𝐷𝑘𝑚2_𝑐𝑜𝑛𝑡𝑒𝑠𝑡 = 𝐴𝐷
𝑘𝑚2,𝑎𝑝𝑝_𝑆𝐵𝐵_𝑐𝑜𝑛𝑡𝑒𝑠𝑡
𝐹𝐵𝑎𝑛𝑑𝐹𝑎𝑝𝑝= 0.0794
𝑎𝑐𝑡𝑖𝑣𝑒 𝑙𝑖𝑐𝑒𝑛𝑠𝑒𝑠
𝑘𝑚2
where:
ADkm2,app,SSB_contest density of SSB amateur stations / km2 during spectrum contest
ADkm2,_contest density of amateur stations / km2 during spectrum contest
BWocc bandwidth occupied as function of time for application
FBand fraction of amateurs using the band
Fapp fraction of amateurs using SSB in the band.
The value of active licenses is below the number of density of licenses / km2. It can be concluded that
68% of amateur licences operating at 50 MHz frequency range are active during an exceptional event,
which seems to be a high value, but can be considered as a reasonable one.
In the following the spectrum needs calculation, according to the methodology shown in § 3.5 of the
main body text, is done using the following parameters:
– Session duration, Tsession: 4.65 h
– Fraction of time transmitting within a single session, Factivity 0.5
– Observation window, W 24 h
– Number of amateurs km2 0.0794.
Rep. ITU-R M.2478-0 145
When using the above mentioned parameter values with the spectrum needs calculation methodology
of § 3.5 of the main body text, 219 kHz spectrum is required for the SSB contest. This figure is based
on contest log data analysis of the IARU 50 MHz 2017 contest. During the IARU 50 MHz 2018
contest, the spectrum occupancy was measured and it turned out, that the measured spectrum use in
2018 contest was much lower than the calculated one (based on log data analysis) for 2017. But it
should be noted, that the propagation conditions during the 2018 MHz contest were significantly
worse than in 2017. Therefore the results of the occupancy measurements results of the 2018 contest
cannot be considered as representative and are disregarded for the spectrum needs calculations.
It can be concluded, that the available spectrum in the Frequency band 50 – 52 MHz assigned for
radio amateur service is by far not saturated in Switzerland during SSB contest situation. Even for
countries with twice the amateur license density of Switzerland, the band would not be saturated.
A15.5 Future amateur spectrum needs for the case where additional spectrum is required in
a country with average amateur license density
As shown in the previous section, it can be assumed that in current situations where exceptional high
amateur station activity is expected, a density of 0.0794 stations / km2 active stations can be assumed
in Switzerland. 8% of them are accessing the 50-52 MHz frequency band. To obtain a forecasted
density figure, which considers a growth of 10.4% the following calculation method is applied:
𝐴𝐷𝑘𝑚2_𝑓𝑢𝑡𝑢𝑟𝑒 = 𝐴𝐷𝑘𝑚2_𝑐𝑜𝑛𝑡𝑒𝑠𝑡 ∙ 1.104 = 0.08740 𝑠𝑡𝑎𝑡𝑖𝑜𝑛𝑠
𝑘𝑚2
The spectrum needs methodology of section 3.5 of the main body text is used to calculate the required
spectrum using the following parameters:
– Session duration, Tsession for SSB 4.65 h
– Observation window, W for SSB 24 h
– Observation window, W for FM and WB 8 760 h
– Observation window, W for Repeaters and Infrastructure 8 760 h
– Session duration, Tsession for FM and WB 730 h
– Session duration, Tsession for Repeaters and Infrastructure 8 760 h
– Fraction of time transmitting within a single session, Factivity 0.5
– Number of amateurs km2 0.08740
– Fraction of Amateurs using SSB, FM, WB, Repeaters, Infrastr. 0.6, 0.05, 0.05, 0.2, 0.1.
When calculating with those parameters, the following requirement results are obtained:
– SSB 240 kHz
– FM 25 kHz
– WB modes 500 kHz
– Repeaters 100 kHz (No contest use but only average day use)
– Infrastructure 500 kHz (No contest use but only average day use).
It can be seen, that the applications “repeaters” and “infrastructure” need the major part of spectrum
during very high activity situations (where additional spectrum is required). This is mainly due to
their very high operation DC which never goes below 50%. However, it is unclear whether those
applications are really relevant for very high activity situations like amateur contests.
146 Rep. ITU-R M.2478-0
A15.6 Future amateur spectrum needs in a country with high amateur license density
According Table A2.1 the highest density of amateur radio stations in Europe is 0.3477, when the
extreme values of countries such as Albania, Belarus, Latvia, Malta, Monaco and San Marino are not
considered. This density is 2.98 times higher than the density considered in calculations for a typical
European country. Accordingly, the densities for the active radio amateur stations used in the
calculations above, need to be multiplied with the factor 2.98, such that a density of active 50 MHz
stations for the average use case is considered to be 0.0154 and for the contest situation 0.26 stations
/ km2.
When calculating with those parameters, the following requirement results are obtained for the
average use case:
– SSB 21 kHz
– FM 25 kHz
– Repeaters 200 kHz
– WB modes 500 kHz
– Infrastructure 500 kHz.
When calculating for the use case, where addition spectrum is required (e.g. in contest situations), the
following figures are obtained:
– SSB 477 kHz
– FM 25 kHz
– Repeaters 200 kHz
– WB modes 500 kHz (No contest use but only average day use)
– Infrastructure 500 kHz (No contest use but only average day use).
As earlier noted, in assuming an average session duration of 45 seconds, a large margin is considered.
This is also confirmed by the measurement results of the four month spectrum monitoring campaign.
Accordingly the calculated needs for the SSB contest may be overestimated.
A15.7 Spectrum needs summary
The spectrum needs are calculated for two different usage situations:
– Case A: Average use case which occurs with a probability of 98% in time.
– Case B: Where additional spectrum is required. This situation occurs e.g. during contests and
special events. It is assumed, that contests and special events do not occur during more than
7 days a year. This corresponds to situations which occur with probability of less than 2% in
time.
In Table A15.2 different spectrum use options are shown. For each option the required spectrum and
the percentage of time during which the spectrum needs are fulfilled is indicated.
Rep. ITU-R M.2478-0 147
TABLE A15.2
Spectrum use options
Option Usage
situation Applications
Amateur
population
density
Required
Spectrum
(MHz)
Spectrum
needs in %
of time
1 Case A SSB, FM, WB average 0.534
98% high 0.546
2 Case B SSB, FM, WB average 0.765
2% high 1.002
3 Case A SSB, FM, WB, Repeaters average 0.634
98% high 0.746
4 Case B SSB, FM, WB, Repeaters average 0.865
2% high 1.202
5 Case A SSB, FM, WB, Repeaters,
Infrastructure
average 1.034 98%
high 1.246
6 Case B SSB, FM, WB, Repeaters,
Infrastructure
average 1.365 2%
high 1.702
Attachment 1
to Annex 15
Spectrum Monitoring and Spectrum Occupancy Results
In a spectrum monitoring campaign, the spectrum occupancy has been measured in an average
populated European country in the period April – July 2018.
The spectrum occupancy measurement system which was used for this study counts the number of
emissions which last minimum 1 second but not longer than 45 seconds within a bandwidth of 5 kHz.
Accordingly the result of the measurements are a certain number of counts in a certain bandwidth. As
an example, a monitored signal with 2.7 kHz bandwidth and a duration of 130 seconds causes at least
3 counts but not more than 6 counts. A signal with 16 kHz bandwidth and 130 seconds duration causes
at least 16 counts but not more than 20 counts. Accordingly 1 count represents the full or partly
occupancy of a 5 KHz channel during 45 seconds. Obviously the results of the described method
represent always an overestimate but never an underestimate of the spectrum occupancy.
Only emissions are counted which originate within the Swiss borders.
The monitoring measurements are based on the following existing amateur region 1 band plan as
shown in Table A15.3.
148 Rep. ITU-R M.2478-0
TABLE A15.3
The occupancy measurement is based on a 5 kHz resolution bandwidth. The measured occupancy of
the band 50.0-50.1 MHz may be underestimated in a certain sense, because simultaneous
transmissions of telegraphy stations within a 4 kHz bandwidth are counted as a single band 1 kHz
frequency band occupation. On the other hand, the occupancy of the 50.5-52 MHz may be
overestimated, because a single 12.5 kHz signal emission may be counted as an occupation of
three channels. However, in view of the very weak band usage, this overestimation does not change
the conclusion that the band usage is negligible.
During the period of April – July 2018 the number of counts as shown in Table A15.4 are obtained
on average for the different frequency sub-bands and scenarios:
Rep. ITU-R M.2478-0 149
TABLE A15.4
Spectrum monitoring results (number of counts)
Scenario Frequency
(MHz) Application
Number
of counts
Average day
50.0-50.1 Telegraphy 107.8
50.1-50.5 All Narrowband modes
(Telegraphy, SSB etc.) 967.9
50.5-52.0
Digital communications
FM Repeaters in / out
FM
FAX, RTTY, etc.
263.1
Exceptional
propagation
conditions
(Opening 28.05.18)
50.0-50.1 Telegraphy 884
50.1-50.5 All Narrowband modes
(Telegraphy, SSB etc.) 3499
50.5-52.0
Digital communications
FM Repeaters in / out
FM
FAX, RTTY, etc.
49
IARU
50 MHz
Contest
Max (16.07.18,
17.07.18)
50.0-50.1 Telegraphy 1358
50.1-50.5 All Narrowband modes
(Telegraphy, SSB etc.) 8775
50.5-52.0
Digital communications
FM Repeaters in / out
FM
FAX, RTTY, etc.
25
The occupancy (%) for the different applications is calculated as follows:
𝑂𝑐𝑐𝑇𝑒𝑙𝑒𝑔𝑟𝑎𝑝ℎ𝑦(%) =∑
𝑇𝑛24∙𝑇
100𝑁𝑏𝑐𝑜𝑢𝑛𝑡𝑠𝑇𝑒𝑙𝑒𝑔𝑟𝑎𝑝ℎ𝑦𝑛=1
(50′100𝑘𝐻𝑧−50′000𝑘𝐻𝑧)
1 𝑘𝐻𝑧
𝑂𝑐𝑐𝑁𝑎𝑟𝑟𝑜𝑤 𝐵𝑎𝑛𝑑(%) =∑
𝑇𝑛24∙𝑇
100𝑁𝑏𝑐𝑜𝑢𝑛𝑡𝑠𝑁𝑎𝑟𝑟𝑜𝑤𝑏𝑎𝑛𝑑
𝑛=1
(50′500𝑘𝐻𝑧−50′100𝑘𝐻𝑧)
5 𝑘𝐻𝑧
𝑂𝑐𝑐𝑎𝑙𝑙 𝑚𝑜𝑑𝑒𝑠(%) =∑
𝑇𝑛24∙𝑇
100𝑁𝑏𝑐𝑜𝑢𝑛𝑡𝑠𝑎𝑙𝑙 𝑚𝑜𝑑𝑒𝑠1
(52′000𝑘𝐻𝑧−50′500𝑘𝐻𝑧)
15 𝑘𝐻𝑧
where:
OccTelegraphy: occupation of the frequency band 50.0-50.1 MHz
OccNarrowband: occupation of the frequency band 50.1-50.5 MHz
Occall modesy: occupation of the frequency band 50.5-52.0 MHz
Nb_countsTelegraphy: number of measured emissions within the band 50.0-50.1 MHz
Nb_countsNarrowband: number of measured emissions within the band 50.1-50.5 MHz
Nb_countsall modes: number of measured emissions within the band 50.5-52.0 MHz
Tn: duration of a single emission (rounded up to integer multiples of 45 seconds)
150 Rep. ITU-R M.2478-0
T: 3 600 seconds.
TABLE A15.5
Spectrum occupancy
Scenario Frequency
(MHz) Application
Maximum
Occupancy
(45 s) (rounded
up)
Average day
50.0-50.1 Telegraphy 0.0561%
50.1-50.5 All Narrowband modes
(Telegraphy, SSB etc.) 0.630%
50.5-52.0
Digital
communications
FM Repeaters in / out
FM
FAX, RTTY, etc.
0.137%
Exceptional
propagation
conditions
(Opening
28.05.18)
50.0-50.1 Telegraphy 0.460%
50.1-50.5 All Narrowband modes
(Telegraphy, SSB etc.) 2.28%
50.5-52.0
Digital
communications
FM Repeaters in / out
FM
FAX, RTTY, etc.
0.0255%
IARU
50 MHz
Contest
Max(16.07.18,
17.07.18)
50.0-50.1 Telegraphy 0.707%
50.1 – 50.5 All Narrowband modes
(Telegraphy, SSB etc.) 5.71%
50.5 – 52.0
Digital
communications
FM Repeaters in / out
FM
FAX, RTTY, etc.
0.013%
A graphical representation of the occupancy for some sample days is shown in Figs A15.1 to A15.6.
Rep. ITU-R M.2478-0 151
FIGURE A15.1
Spectrum occupancy measured during the 19.5.2018
FIGURE A15.2
Spectrum occupancy measured during the 28.5.2018
0
10
20
30
40
50
60
70
80
90
1005
0.0
9
50
.1
50
.11
50
.12
50
.13
50
.14
50
.15
50
.16
50
.17
50
.19
5
50
.29
50
.30
5
50
.32
50
.4
50
.72
50
.83
5
51
.04
5
51
.15
5
51
.23
5
51
.37
5
51
.80
5
51
.83
51
.84
51
.95
51
.97
5
19.Mai 2018
0
10
20
30
40
50
60
70
80
90
100
50
.06
50
.07
5
50
.09
50
.10
5
50
.12
50
.13
5
50
.15
50
.16
5
50
.18
50
.19
5
50
.22
50
.29
5
50
.31
50
.32
5
50
.34
5
50
.41
5
50
.65
5
50
.85
51
.11
5
51
.30
5
51
.37
5
51
.50
528. May 2018
Ergebnis
152 Rep. ITU-R M.2478-0
FIGURE A15.3
Spectrum occupancy measured during the 13.5.2018
FIGURE A15.4
Spectrum occupancy measured during the 17.6.2018
0
10
20
30
40
50
60
70
80
90
100
13. Mai 2018
0
10
20
30
40
50
60
70
80
90
100
50
.06
50
.07
5
50
.09
50
.10
5
50
.12
50
.13
5
50
.15
50
.16
5
50
.18
50
.19
5
50
.21
50
.22
5
50
.27
5
50
.30
5
50
.32
50
.4
50
.85
5
51
.36
51
.87
5
IARU Contest 17. June 2018
Ergebnis
Rep. ITU-R M.2478-0 153
FIGURE A15.5
Spectrum occupancy measured during the 30.6.2018
FIGURE A15.6
Spectrum occupancy measured during the 24.6.2018
It can be noted, that the use of digital modes, FM and repeaters in the 50 MHz spectrum is obviously
not very popular, as the spectrum is nearly unused by those application during most of the times.
When using the occupancy measurement data, to calculate the occupied bandwidth and comparing
those results to results of two existing spectrum needs studies, it can be concluded that both studies
make very probably an overestimate of the required spectrum. A summary of the comparison is shown
in Table A15.6.
0
10
20
30
40
50
60
70
80
90
100
30. June 2018
0
10
20
30
40
50
60
70
80
90
100
24. July 2018
154 Rep. ITU-R M.2478-0
TABLE A15.6
Comparison of calculated spectrum requirements and occupied
bandwidth for existing applications
Sp
ectr
um
usa
ge
situ
ati
on
Applications
Frequency
range
(MHz)
Current average
occupied
bandwidth in a
typical European
country
measured during
a four-month
period in spring
2018
Future spectrum
needs (MHz)
according
Study 1
Future spectrum
needs (MHz)
according
Study 2
Du
rin
g
aver
age
day
s
(98
% o
f ti
me)
Existing
Applications
Narrow band &
Telegraphy 50.0 – 50.5
0.003 MHz*
(0.0561 kHz
+ 2.52 kHz)
0.009 MHzav
0.021 MHzhigh
0.087 MHzav
0.25 MHzhigh
FM, Repeaters,
Digital, etc. 50.5 – 52.0
0.025 MHz*
(1.69 kHz)
0.125 MHzav
0.225 MHzhigh
0.975 MHzav
2.7 MHzhigh
New
applications
Wide Band,
Infrastructure > 50.5 n.a.
1.0 MHzav
1.0 MHzhigh
3.0 MHzav
7.0 MHzhigh
Du
rin
g
con
test
s an
d
exce
pti
on
al
con
dit
ion
s
(du
ring
2%
of
tim
e)
Existing
Applications
Narrow band &
Telegraphy 50.0 – 50.5
0.219 MHz*
(Contest 2017)
0.24 MHzav
0.477 MHzhigh n.a.
FM, Repeaters,
Digital, etc. 50.5 – 52.0
0.025 MHz*
(0.033 kHz)
0.125 MHzav
0.225 MHzhigh n.a.
New
Applications
Wide Band,
Infrastructure > 50.5 n.a.
1.0 MHzav
1.0 MHzhigh n.a.
To
tal
ma
x. All
applications All modes - n.a.
1.365 MHzav
1.702 MHzhigh
4.062 MHzav
9.95 MHzhigh
* To integer multiples of channel band width rounded up values.
** Result of 2017 amateur contest is representative because propagation conditions during the 2018 contest were rather
poor for typical amateur communication activities.
The occupied bandwidth measurement results for FM, Repeaters, Digital modes etc. are rounded up
to a single 15 kHz channel.
It should be noted that the spectrum needs according to Study 1 are based on parameter values which
are calculated based on a combination of the IARU 50 MHz 2017 contest log data analysis and
spectrum monitoring results. It may be possible, that the contest of 2018 was less crowded that that
one in 2017.