WRC 2019 Agenda Item Details

Agenda Item: Agenda Item 9.1.3
Resolution(s): Resolution 157 [COM5/6] (WRC-15)
Description of work:

This issue involves the study of technical and operational issues and regulatory provisions for new non-geostationary-satellite orbit systems in the 3 700-4 200 MHz,4 500-4 800 MHz, 5 925-6 425 MHz and 6 725-7 025 MHz frequency bands allocated to the fixed-satellite service.

The Resolution invites the ITU-R to study:

  1. a possible revision of Article 21 Table 21-4 for non-GSO FSS satellites in 3 700 - 4 200 MHz while ensuring existing mobile and fixed services are protected,
  2. possible revisions of the EPFD(down) and (up) in Article 22 for the 3 700 - 4 200 MHz and 5 925 - 6 425 MHz bands while ensuring the GSO networks are protected from unacceptable interference,
  3. the possible development of EPFD(down) and EPFD(up) limits to include in Article 22 for the 4 500 - 4 800 MHz and 6 725 - 7 025 MHz bands for non-GSO systems while protecting GSO networks from unacceptable interference,
  4. the protection of MSS feeder links in the s-E direction in the 6 700 - 7 025 MHz band from non-GSO FSS systems operating in a E-s direction,
  5. development of appropriate regulatory provisions in the 4 500 - 4 800 MHz band to protect terrestrial services from non-GSO FSS systems operating in the s-E direction,
  6. development of regulatory provisions to clarify that 5.440A and 5.547C would apply to ensure that non-GSO FSS systems do not cause harmful interference to or claim protection from AMT for flight testing by aircraft stations.
Comments: The existing EPFD limits in Article 22 for these bands were developed for non-GSO FSS systems in highly elliptical orbits which have a very different geometry to those in circular orbits, in particular with respect to the GSO. This means that the EPFD levels generated over time have a very different cumulative distribution function. There can be any number of EPFD limits that would result in the same degradation in unavailability of a GSO system and so it is possible for other EPFD limits to be defined that provide the necessary protection to the GSO while permitting circular orbit non-GSO FSS to proceed.
Lead Working Party(s): WP 4A
Involved Working Parties: WP 3M, WP 5A, WP 5C
How Visualyse products can help: Visualyse Professional can model GSO and non-GSO networks sharing in this band. There are a host of features designed to support this type of sharing analysis including tracking strategies (GSO arc avoidance, non-GSO constellation avoidance), steerable spot beams (GSO and non-GSO), GSO shaped beams, orbit dynamics, reading GSO and non-GSO from IFIC/SRS databases, service area and coverage analysis, statistics involving I/N, C/I, C/(N+I), PFD and EPFD metrics, traffic modelling and resource management features. The analysis could either be undertaken assuming clear air (free space) propagation (as used for EPFD analysis) or including gaseous attenuation and/or rain P.618. Visualyse EPFD can be used to determined whether a non-GSO FSS network would meet the proposed EPFD limits before they are agreed.
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 criterias, and provide contributions and representation at the ITU-R WPs. Using our in house Visualyse Professional we can quickly model a very wide range of systems, services and scenarios. We have particular experience modelling non-GSO systems and are world experts on issues relating to the algorithm in Rec. ITU-R S.1503 and the verification EPFD limits. As primary authors of Rec. S.1503 we are in a unique position to support its revision should that be required
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