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RALI FX3 Microwave Fixed Services Frequency Coordination. Glenn Odlum Senior Engineer Spectrum Engineering Section glenn.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
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RALI FX3Microwave Fixed ServicesFrequency Coordination Glenn Odlum Senior Engineer Spectrum Engineering Section glenn.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 - 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
Antenna Requirements : Refer to Appendix 11 Example
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
TX(f1) TX(f1) A C RX(f1) RX(f1) B D Coordination Problem 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