WRC 2023 Agenda Item Details

Agenda Item: Agenda Item 1.1
Resolution(s): Resolution 223 (Rev. WRC-19)
Description of work:

This agenda item relates to consideration of conditions for which the band 4 800 - 4 825 and 4835 - 4 950 MHz could be used by terrestrial component of IMT, in accordance with Resolution 223 (WRC-19). In particular, it addresses technical and regulatory conditions, such as power flux density (pfd) limits, which could protect aeronautical and maritime mobile services.

Subject to review by WRC-23 these conditions are:

  1. in the frequency band 4 800 - 4 825 MHz and 4 835 - 4 950 MHz the coordination distance in relation to aircraft stations is 300 km (land paths) or 450 km (sea paths)
  2. in the frequency band 4 800 - 4 990 MHz the coordination distance in relation to fixed-service stations or other ground-based stations of the mobile service is 70 km
  3. a PFD threshold in No. 5.441B which does not apply to the countries listed in Resolves 5 of the Resolution
Comments: This topic was discussed at WRC-19 with a significant number of countries adding their name to footnote 5.441B which identified the frequency band 4 800 - 4 990 MHz for IMT in the named countries subject to a pfd of -155 dBW/m^2/MHz to protect stations in the aeronautical mobile service. The pfd threshold was subject to review at the next conference. In addition, under AI 9.1 as the Director's Reported noted in Section 3.6.6 that there were discussions at WP 5D that identified possible inconsistencies in the RR and that "the Conference is invited to consider the matter and take appropriate action". Note that the Resolution also asks the ITU-R to study technical measure to ensure coexistence between MSS in the band 1 518 - 1 525 MHz and IMT in the band 1 492 - 1 518 MHz.
Lead Working Party(s): WP 5B, WP 5D
Involved Working Parties: WP 1B, WP 3K, WP 3M, WP 5C, WP 7D
How Visualyse products can help: Visualyse Professional can model sharing between mobile including IMT services and the aeronautical and maritime mobile services. This analysis can be static, area, dynamic or Monte Carlo including adjacent band studies. A range of propagation models could be used including P.452, P.1546, P.1812, P.2001 or generic dual or triple slope including Hata / COST 231. The analysis can determine if an IMT system will meet / exceed a pfd threshold and whether the pfd threshold would protect the victim services. Visualyse Professional can also model the beam-forming antenna gain pattern in Recommendation ITU-R M.2101.
How Transfinite consultants can help: We can undertake studies including analysis of sharing between the services covered by this agenda item, and identify suitable system characteristics and sharing criteria, and provide contributions and representation at ITU-R Working Parties. Using our in house Visualyse Professional we can quickly model a very wide range of systems, services and scenarios.
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