As a part of the preparatory process for WRC-23 agenda item 9.1 topic b) involving the 23cm band, ITU‑R Report M.2532 has just been published. This report encapsulates the outcome of resolves 1 of ITU‑R Resolution 774 that requires a detailed review of the different systems and applications used by the amateur and amateur satellite services in the 23cm band. The review forms a part of the basis for the studies required by resolves 2 to address the amateur and amateur satellite services coexistence with the radio navigation satellite service (RNSS).

The report M.2532 can be found here.

The publication represents a positive outcome from a great deal of work and committment by the IARU volunteer team that has been central to its development since 2019 in ITU‑R Study Group 5.

Working Party 5A meeting #30 met over the period 13^th to 22^nd September 2023 and despite extra meeting time allocated specifically to the development of the ITU‑R Recommendation M.[AS_GUIDANCE] the meeting did not reach a consensus on the technical and operational measures required to ensure the protection of the RNSS (radio navigation satellite service) in the amateur 23cm band. The measures aim to identify parts of the frequency band with associated amateur transmitter power limits that can help protect the RNSS operations. By the close of the meeting three alternative solutions remained unresolved in the draft document.

This outcome was reported to the WP5A plenary meeting and the subsequent parent Study Group 5 meeting but despite further efforts still no outcome could be achieved. Since the recommendation will be important for WRC-23 discussions it is expected that further efforts will continue to try to find a solution.

On a positive note the Draft New Report ITU‑R M. [AS_CHARACTERISTICS] was finalised by WP5A an approved in Study Group 5.

The IARU report from the WP5A meeting can be downloaded here.

Throughout the ITU‑R WRC-23 preparatory work the IARU has maintained its position that the regulatory status of the amateur and amateur satellite services in this range is already clear. Therefore any developments to add new regulatory, operational or technical measures to be incorporated as new mandatory elements into the Radio Regulations are opposed. The final position can be found here.

ITU‑R Working Party 4C meeting #30 could not agree on the technical and operational measures required to ensure the protection of the RNSS (radio navigation satellite service) in the amateur 23cm band. (Relating to WRC-23 AI 9.1b).

Working Party 4C met over the period 21^st to 27^th June 2023 and discussed several contributions relating to the draft Recommendation ITU‑R M.[AS_GUIDANCE] under development in WP5A . The group struggled to find consensus amongst the RNSS community on the measures it could propose to WP5A.

However the working party did accept a contribution from the IARU presenting a Monte Carlo style study that shows the low percentage of RNSS receivers located around an amateur transmitter that are likely to be in a position to suffer interference. The study will be incorporated as a revision to the ITU‑R Report M.2513.

The IARU report from the WP4C meeting can be downloaded here.

The outcome of the discussion and final elements of the ITU‑R Recommendation remain uncertain and work on this topic will continue at the next ITU‑R WP5A meeting in September with some urgency to finalise ahead of the WRC.

At the last CEPT CPG meeting #8 during May, the CEPT put its weight behind the development of a European Common Proposal (ECP) that would in effect mandate the technical and operational guidance under development in ITU‑R WP5A to allow the amateur and amateur satellite services to continue to operate and avoid interference to the RNSS.

A summary report from the CPG meeting #8 can be found here.

The IARU is supporting the development of an ITU‑R Recommendation to identify the technical and operational constraints that might be required by the amateur and amateur satellite services in the 23cm band. However, the IARU continues to assert that WRC23 does not need to make any changes to the Radio Regulations for this Recommendation under development in WP5A to be effective.