The IARU Region 1 Spectrum Regulation and Liaison Committee (SRLC) chair took part in a joint session with the R1 Political Relations Committee (PRC) during the member society International Meeting convened during the HamRadio2022 Friedrichshafen event. The session highlighted the connections the SRLC maintains with Region 1 regulatory bodies and the work carried out since early 2021. This included engagement in the WRC23 preparatory activities in a number of regional bodies and the detailed study work both with ITU‑R and CEPT. The hot topics affecting amateur spectrum bands were summarised with particular attention being paid to the 23cm band topic on the agenda of WRC23.

The SRLC slide set can be found here.

Further detailed information on the 23cm band topic can be found here.

The latest meeting of ITU‑R WP5A concluded on June 2, 2022. The IARU was represented by Ole Garpstad (LA2RR – ITU Lead) and Barry Lewis (G4SJH – WRC23AI9.1b Lead).

ITU‑R WP5A is the study group at ITU which deals in part with topics related to the amateur and amateur satellite services. It is the lead group responsible for developing the Conference Preparatory Meeting (CPM) report on agenda item 9.1(b) This Agenda Item provides for a “Review of the amateur service and the amateur-satellite service allocations in the frequency band 1 240‑1 300 MHz to determine if additional measures are required to ensure protection of the radionavigation-satellite (space-to-Earth) service operating in the same band in accordance with Resolution 774 (WRC‑19);” The CPM Report will form the basis for consideration of this issue at WRC-23 next year.

At the conclusion of the recent WP5A meeting a draft recommendation was prepared which will provide guidelines to administrations to ensure the protection of the RNSS primary allocation from the secondary amateur and amateur satellite services.

The draft recommendation will be the most important element of the WP5A work going forward for the amateur and amateur satellite services in the 23cm band. The working document contains a number of proposals for severe limitations on amateur usage of the band including transmitter power constraints. Very low power levels are proposed for large portions of the band (100% in one case). Proposals also identify possible frequency band usage limitations for broadband applications (e.g. ATV), narrowband applications and amateur satellite services in 1 260 – 1 270 MHz.

A full report of the WP5A meeting can be found here.

None of these proposals are adopted at this time and work will continue at the next meeting of WP5A to rationalise the variations proposed by national telecom-administrations. The IARU will work to minimise the constraints on amateur radio activities and continue to seek amendments to the draft recommendations through the ITU process, but as a secondary user, radio amateurs should understand the need to protect the Radionavigation Satellite Service (RNSS) in many consumer and industry applications (like autonomous vehicles) that will lead to some restrictions on our use of the 23 cm band.

A detailed slide set relating to this topic can be found here.

The IARUMS Region 1 Newsletter May 2022 is now available.
Click on the link to read it!

During the period 4 – 10 May 2022, the IARU continued to engage in the preparatory work for WRC-23 agenda item 9.1b in ITU‑R Working Party 4C (WP4C).

Work continued to develop the coexistence studies between the amateur services in the 23cm band and the radio-navigation satellite services (RNSS) operating across the band. New studies were submitted by France, China and the Russian Federation.

The scale of the problem for the amateur services is becoming clear. For example, the studies predict that even a relatively low power 23cm band station could cause interference to distant RNSS receivers on the antenna main beam heading. Although the level of amateur activity and the density of users is quite low (compared to other more popular bands) the issue remains that from a regulatory perspective the amateur services are required to not cause harmful interference to RNSS services.

The figure below is a sample of one result from one study submitted into ITU‑R. In this example a station using an 18dBi gain antenna is used for both narrow band transmissions 100W. The protection criteria for the RNSS receivers differs for narrowband and wideband interfering signals. The figure shows the distances out from the amateur station where the RNSS protection criteria could be exceeded around the amateur station antenna .

These results have been developed based the ITU‑R defined receiver protection level for the GALILEO RNSS. For the narrow band modes this is ‑134.5dBW and for the wideband modes is ‑140dBW/MHz. In addition, measurement campaigns have shown that an improvement in the compatibility potential can be seen if the amateur signals avoid the centre portion of the GALILEO receiver passband.

Of course the studies cannot take into account every possibility that might mitigate the problem (e.g clutter, terrain blocking etc.) but it is clear that the potential for interference is considerable. 

The IARU is working hard to ensure that the amateur service can continue to develop in this band and allow all the amateur applications in use today to continue. However, given the heavy spectrum occupancy of the band by the various RNSS systems it is evident that proposals will come calling to restrict our ability to operate in certain parts of the band and at the power levels possible today. IARU is totally engaged in the discussion of these considerations and these will continue within ITU‑R (and other regional bodies).

The IARU summary report on the WP4C meeting can be found here which in turn includes a link to the full draft study.

The IARUMS Region 1 Newsletter April 2022 is now available.
Click on the link to read it!