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Empirical compatibility assessment in PolandLTE causes interference to ARNS
Mateusz BerlikOffice of Electronic Communications, Poland
Department of Frequency Resources Management
ITU Regional Seminar for Europe and CIS CountriesWarsaw, 7 - 9 May 2012
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Agenda
• Introduction to the LTE vs. ARNS problem• Aims and conditions of the measurements• Radio systems under tests• Measurements action• Summary
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Agenda
• Introduction to the LTE vs. ARNS problem• Aims and conditions of the measurements• Radio systems under tests• Measurements action• Summary
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Introduction to the LTE vs. ARNS problemWRC-12 AI 1.17 - to consider results of sharing studies between the mobile service and other services in the band 790-862 MHz in Regions 1 and 3, in accordance with Resolution 749 (WRC-07), to ensure the adequate protection of services to which this frequency band is allocated, and take appropriate action.
MOBILE
FIXED BROADCASTING
ARNS
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Introduction to the LTE vs. ARNS problem
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Introduction to the LTE vs. ARNS problem
• Two approaches proposed by CPM-12:– coordination distances: 125 – 515 km
(depending on ARNS system and scenario)– coordination field strength triggers
• aggregate values – eg. 13 dBµV/m @ 10m in 6 MHz RBW for RLS1 radar;
• single values – eg. -24.24 dBµV/m @ 10m for ARNS terrestrial station
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Introduction to the LTE vs. ARNS problem
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Introduction to the LTE vs. ARNS problem
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Agenda
• Introduction to the LTE vs. ARNS problem• Aims and conditions of the measurements• Radio systems under tests• Measurements action• Summary
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Aims of the measurements:
• to analyse an impact of the LTE system on the radar system;
• to determine/assess the maximum level of the interfering signal.
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
What did we have?
• 4 ARSN systems operating in Poland;• agreement of the army on measurements
(with some restrictions);• LTE test terminals (provided by the
operator);• LTE signal generator (provided by Nokia
Siemens Networks Poland);• ARNS’s system operators/service staff.
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
What did we NOT have?
• detailed knowledge about the ARNS systems;
• documentation of the ARNS systems;• specialists in old ARNS systems;• compatibility criteria(!).
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Agenda
• Introduction to the LTE vs. ARNS problem• Aims and conditions of the measurements• Radio systems under tests• Measurements action• Summary
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Scenario
LTE terminal/signal generator ARNS ground station
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Object of the measurements
• RSP-10 MN-1 radar system:– primary (RLS1) / secondary (RLS2) radar;– only RLS1 module currently in use;– radiolocator for traffic controllers;– less than 100 km operational radius;– is going to be replaced by modern systems.
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
RSP-10 Radar system (RLS1)
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
RSP-10 Radar system (RLS1)
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
RSP-10 Radar system (RLS1)
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
RSP-10 Radar system (RLS1)
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Agenda
• Introduction to the LTE vs. ARNS problem• Aims and conditions of the measurements• Radio systems under tests• Measurements action• Summary
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Military base15-16.02.201130.03.2011
Military airfield17-18.02.2011
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Measurement I (Toruń, 15-16.02.2011)
• The radar under maintenance works;• Direct connection to the radar receiver.
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
RSP-10
(part of RSP10)
G4-76A 75/50
RSP-10
50/75
indicator
oscilloscope
receiver unit
LTE signal generator
Signal
generator
Power adder
(double pulse)
Pulse gen.
2 dB 2 dB
6 dB 0.3 dB 0.4 dB
0.4 dB
0.4 dB 0.3 dB
Measurement I (Toruń, 15-16.02.2011)
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Measurement I (Toruń, 15-16.02.2011)
LTE parameters:
Bandwidth [MHz] 5 5 10 20 5 5
Modulation QPSK 16-QAM 16-QAM 16-QAM 16-QAM 16-QAM
G4-76A generator settings:
„Reflected” signal [dBm] - 92.3 - 92.3 - 92.3 - 92.3 -82.3 -72.3
LTE generator „critical” power:
LTE Power [dBm] - 89.1 - 89.1 - 89.1 - 89.1 -87.1 -87.1
Sensitivity: -92.3 dBm Pol H: E = 24.6 dBμV/mPol V: E = 48.6 dBμV/m
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Measurement II (Malbork, 17-18.02.2011)
• Operating radar used by military airfield in Malbork
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Measurement II (Malbork, 17-18.02.2011)
• The radar in „receive-only” mode:– very optimistic results
(allowable interference > 50 dBµV/m);• Received interference’s level dramatically
higher when it works in regular „send-and-receive” mode;– there was no ability to repeat the
measurements.
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Measurement III (Toruń, 30.03.2011)
• Operating radar (after maintenance works);• Measurements similar to ones performed in
Malbork;• LTE terminals as interfering transmitters.
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Measurement III (Toruń, 30.03.2011)
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Measurement III (Toruń, 30.03.2011)
Measure No. Received power [dBm]
Field strength at receiving
point [dBμV/m]
Distance [m] Frequencies
1 -95,2 35,5 706RSP-10: 835 MHzLTE: 834.75 MHz
2 -96,5 34,2 1 488RSP-10: 835 MHzLTE: 834.75 MHz
3 -96,3 34,4 1 504RSP-10: 835 MHzLTE: 834.75 MHz
4 -80,3 50,4 128RSP-10: 835 MHzLTE: 839.5 MHz
5 -69,7 61,0 128RSP-10: 835 MHzLTE: 840.5 MHz
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Agenda
• Introduction to the LTE vs. ARNS problem• Aims and conditions of the measurements• Radio systems under tests• Measurements action• Summary
Mateusz Berlik, UKE :: Warsaw, 7 - 9 May 2012
Summary
• Because of the lack of the technical compatibility criteria, it was difficult to use the results as a point in discussion.
• General conclusions:– LTE terminal does really interfere RSP-10 radar;– allowable interference field strength is probably higher
than protection level from the CPM-12 Report.• The results were useful for our administration.