ITU‑R Working Party 5A meeting #29 and the 23cm band and RNS

[IK0ZCW]

ITU‑R Working Party 5A meeting #29 and the 23cm band and RNSS (radio navigation satellite service) coexistence measures relating to WRC-23 AI 9.1b

May 26, 2023 - Spectrum - Barry, G4SJH



Over the period 9th to 19th May 2023, the preparatory work for WRC-23 agenda item 9.1b continued in ITU‑R Working Party 5A (WP5A). Two deliverables are under discussion:

1) Draft ITU‑R Report M.[AMATEUR_CHARACTERISTICS] – this reports on the specific 23cm band amateur and amateur satellite service technical parameters and operational characteristics used in the studies now published in ITU‑R Report M.2513 – 0.

2) Draft ITU‑R Recommendation M.[AS_GUIDANCE] – this will recommend guidance that national administrations can take to facilitate the protection of the radio navigation satellite service from harmful interference from amateur radio stations.

Ahead of this WP5A meeting the IARU global WRC-23 9.1b team led by G4SJH developed and submitted two contributions, one for each deliverable above. As usual, the IARU participated in the meeting to present the contributions and take part in the ongoing discussion and negotiations. The IARU contribution to the Guidance recommendation proposed specific limits for EME operation in the range 1296 – 1300 MHz. The proposal was largely adopted but only in the range 1298 – 1300 MHz. The IARU contribution to the “characteristics” report proposed an annex containing a Monte Carlo style study assessing the impact of a range of amateur transmissions on a population of RNSS receivers around the amateur station. Contributions were also provided by a number of national administrations and a summary report of the meeting can be downloaded here.

The development of the recommendation is proving challenging although many of the IARU proposals remain in the draft document for further discussion. Challenges are arising from other proposals that could be judged to go beyond the original mandate for the work. In addition some proposals for technical and operational measures seem impractical from both an administration and amateur station perspective.

The study proposed for the characteristics report was accepted for now but is to be liaised to WP4C for consideration and possible revision to Report ITU‑R M.2513.

Meanwhile in CEPT the work in project team SE40 continued during the same period (15 – 17th May) with their development of an ECC Report on the same coexistence problem. IARU contributed the same Monte Carlo study to that group where it now sits in the draft deliverable.

In ITU_R the work on this topic will continue at the next ITU‑R WP5A meeting in September with some urgency to finalise both deliverables ahead of the WRC.