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 21st to 27th 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.