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.