1、QUESTION ITU-R 118-2/7*Factors which affect frequency sharing between data relay satellite systems and systems of other services (1990-1996-2000) The ITU Radiocommunication Assembly, considering a) that data relay satellites are used to relay mission-gathered data, television and voice communication
2、s in manned missions, orbit-tracking data such as position and velocity of the spacecraft, and telecommands for guidance and control of the spacecraft; b) that frequencies between 2 and 30 GHz used by both near-Earth satellite and data relay satellites are shared with other service systems; c) that
3、frequency bands between 20 and 30 GHz are becoming more heavily occupied by existing and planned systems; d) that frequency sharing between space stations of a data relay satellite network and terrestrial systems is feasible, provided: that appropriate power flux-density limits are applied to the em
4、issions of space stations of the data relay satellite networks; that appropriate e.i.r.p. density limits are applied to terrestrial service stations; e) that interference to stations of a data relay satellite network from the emissions of fixed terrestrial stations may result in levels of interferen
5、ce that exceed the protection level when within view of these stations; f) that the use by data relay satellites of interference mitigation techniques such as frequency agility, adaptive interference cancellation and avoidance of mainbeam-to-mainbeam coupling may facilitate sharing with the terrestr
6、ial services, decides that the following Question should be studied 1 What are the services with which, and under what conditions, is the sharing of frequency bands practicable for data relay satellite systems? 2 What are the limits of power flux-density from data relay satellite emissions needed to
7、 protect other services sharing frequencies between 2 and 30 GHz? 3 What are the e.i.r.p. density limitations to be applied to terrestrial service stations to facilitate sharing with data relay satellite networks? 4 What are the implications of interference to stations in a data relay satellite netw
8、ork from the emissions of fixed terrestrial stations in contrast to interference from the emissions of non-stationary, randomly located terrestrial stations? _ *In the year 2009, Radiocommunication Study Group 7 extended the completion date of studies for this Question. - 2 - 5 What are the preferred interference mitigation techniques for use by data relay satellite networks operating above 20 GHz? further decides 1 that the results of the above studies should be included in (a) Recommendation(s); 2 that the above studies should be completed by 2011.
