RALI FX3Microwave Fixed ServicesFrequency Coordination

Glenn OdlumSenior EngineerSpectrum Engineering Sectionglenn.odlum@acma.gov.au

FX3 - Key Points

• Point-to-Point and Point-to-Multipoint Fixed Links in 1 - 60 GHz

• Line-of-Sight systems only• Analogue and Digital Systems • Technical Policy - Planning Rules • Frequency Coordination Procedures• Not a Link Planning Tool

RALI FX3

INPUTS

-Spectrum Plan-ITU Radio Regulations-ITU-R Recommendations -Sharing Requirements-Spectrum Planning Reports-Industry Consultation

OUTPUTS

-Channel Plans-Planning Rules-Coordination Rules

Input - Spectrum Plan

• The Australian Radiofrequency Spectrum Plan identifies which radiocommunications services may operate in which frequency band

• Can’t issue a licence contrary to the Spectrum Plan

• Spectrum Plan may identify a frequency band for fixed service use but FX3 may not have an entry for it

Input - ITU Radio Regulations

• Sets many aspects of fixed services• Article S5 - Frequency allocations by region• Article S15 - Interference• Article S21 - maximum eirp of fixed service

transmitter in direction of a GSO satellite

Input - ITU-R Recommendations

• F- series (Fixed Service)

– Radiofrequency channel arrangements

– Error performance and availability objectives

– Protection criteria (protection from other services)

– Characteristics of fixed services to facilitate sharing with other services

– Many others

Input - ITU-R Recommendations

• Other Series

– IS series - Inter-service sharing and compatibility

– P series - Radiowave propagation– SF series - frequency sharing between the

fixed-satellite service and fixed service– SM series - Spectrum management

Input - Sharing Requirements

• In some bands fixed services are required to share spectrum with other services such as the mobile service, space service, fixed satellite service, or mobile satellite service.

• Sharing may impose restrictions on the fixed service and/or other services

• Increasing demand for fixed service to share with other services

Input - Industry Consultation

• Vital part of policy development• Objective is reach agreement on how to make best

use of a band• Total agreement not always possible• ACMA has a very good working relationship with

most sectors of the industry

Output - Channel Plan

• Usually based on ITU-R recommendations• Takes account of what type of use is supported

(wide-band analogue, FM-FDM, low, medium or high capacity digital)

• Main and interleaf pattern• Centre frequency and channel width• Transmit / receive duplex spacing

Output - Channel Plan

1

1922

2

1951

3

1980

4

2009

5

2038

6

2067

1'

2135

2'

2164

3'

2193

4'

2222

5'

2251

6'

2280

1

1907.5

2

1936.5

3

1965.5

4

1994.5

5

2023.5

6

2052.5

1'

2120.5

2'

2149.5

3'

2178.5

4'

2207.5

5'

2236.5

6'

2265.5

2300

MAIN

2300

INTERLEAVED

2100

213 MHz29 MHz

fo

fo

2100

29 MHz213 MHz

1900

1900

Shared cordless band.No additional fixed servicesAustralia-wide (ref. 2).

Shared mobile satellite service band.No new fixed services Australia-wide (ref. 3).

MDS bands.

1980 2010 2076 2111 2170 2200

Output - Planning Rules

• Expresses many policy requirements• Consists of Assignment Instructions and

Assignment Restrictions on a per band basis and Section 3

• Some flexibility is available on a case-by-case basis

• Planning rules are reviewed from time-to- time

Output - Assignment Instructions

• Specific to each band• Typical use• Assignment priority• Minimum path length• Antenna Requirements• Notes

ExampleASSIGNMENT INSTRUCTIONS

This band is designated for use by medium capacity fixed point-to-point links.Typical Use : 34 Mb/s data, FM videoAssignment Priority : not specifiedMinimum Path Length : 20 kmNotional Antenna : 3.0 m grid parabolic dish

Notes:1. Some channels are not available for assignment, see Assignment Restrictions on page 2.2. Proposed fixed links need to be coordinated with Earth stations operating in this band (ref 7.).3. Proposed fixed links need to be coordinated with MDS services. For coordination with Regional

MDS, see ref. 4. For major city and remote area MDS, use Assessments B and C in Schedule 1 ofref. 5 (major city coordination areas are described in Schedule 1 of ref. 6).

4. Note potential for interference - on channel 1 to/from adjacent 1.8 GHz band fixed services.5. Fixed service licences in this band must not be issued for periods of more than 12 months (see page

2 (Assignment Restrictions 3.1) and ref. 9).

: Refer to Appendix 11Antenna Requirements

Output - Assignment Restrictions

• Identifies constraints placed on assignments• Could be channel or geographic location specific• May express additional coordination requirements• May require application of special conditions or

advisory notes to licences

Output - Protection Ratio

• Sets minimum ratio of wanted signal to unwanted signal (W/U)• Sets the maximum level of unwanted (interference) signal level• Minimum C/I for victim link BER• Allowable BER degradation • Fade margin (multi-path or rain) required on wanted link

(outage time)• NOTE Protection Ratios in FX3 are default values - real

performance parameters of equipment can be used

Frequency Coordination

• Determines the compatibility of a proposed new fixed link service with existing services operating on a particular channel frequency in a given geographic area

• Focus is on the wanted signal to unwanted signal ratio (protection ratio)

Required Data

• Preferred frequency band• Geographic coordinates

of link ends• System type / capacity /

emission details• Nominal mean emission

power• Antenna type and

characteristics

Coordination Problem

TX(f1)

RX(f1) RX(f1)

TX(f1)

A

B

C

D

A B - Existing service route

C D - Proposed service route

A D and C B - Interference path

Basic Coordination Steps

• Identify potentially affected existing fixed services• Calculate wanted and unwanted (interference) levels to

/ from proposed and existing fixed services• Compare levels against the interference management

criteria (protection ratio)• Check compliance with assignment instructions and

policy requirements• Check compliance with sharing requirements for other

services

QuestionsQuestions