Latest news from JTG 4-7-8

Footnote S5.502 of the Radio Regulations states that "in the band 13.75-14 GHz, an earth station in the fixed-satellite service shall have a minimum antenna diameter of 4.5 m". This limit was placed in order to provide some protection to other services that have a primary allocation, in particular the radiolocation service. This large dish size is more expensive for customers, and the result is that less will be installed, and hence there will be less interference from the FSS uplinks in this band into other services.

However recently there has been market demand for smaller, lower cost antennas, and so at WRC 2000 Resolution 733 was passed that invites the ITU-R:

  1. to conduct studies …. on the sharing conditions in Nos. S5.502 and S5.503, with a view to reviewing the constraints in No. S5.502 regarding the minimum antenna diameter of GSO FSS earth stations and the constraints on the e.i.r.p. of the radiolocation service;
  2. to identify and study …. possible alternative sharing conditions to those indicated in Nos. S5.502 and S5.503.

JTG 4-7-8 was set up to examine these issues and report back to WRC 2003. At the meeting in February 2002 interested parties submitted a number of papers that described sharing analysis done based upon the reference models defined at an earlier meeting. The majority of these papers were produced using our Visualyse Professional simulation tool, including:

  • Document 4-7-8/40: A sensitivity study of the sharing between the fixed satellite service and the radiolocation service in the band 13.75-14.00 GHz
  • Document 4-7-8/41: Simulations of alternative sharing conditions between the radiolocation/radionavigation services and fixed-satellite service in the 13.75-14 GHz band
  • Document 4-7-8/44: Study of GSO FSS Earth Station Interference into Shipboard Radar in the 13.75 GHz to 14.0 GHz band
  • Document 4-7-8/45: Protection of Radar Receivers from Interference by FSS Earth Stations Transmitting in the Band 13.75-14 GHz
  • Document 4-7-8/46: Simulations of reference interference scenarios from FSS Earth Stations into Radar receivers

One of these papers was based upon work done by Transfinite Consultancy, and is described in the Consultancy section - select the "Studies" page and then "JTG 4-7-8".

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