Interference in the fixed satellite service bands between the feeder-links of networks using nongeostationary satellites and network using geostationary satellites

The most near-term of the frequency-sharing issues between non-GSO (geostationary orbit) networks and GSO networks seem likely to involve the feeder-links of LEO/MSS systems, and the feeder-links of HEO/BSS(sound) systems. The nature of HEOs is such that frequency sharing between systems using them and systems using the GSO is not likely to call for special measures. Between the feeder-links to MSS/LEO or MSS/MEO systems and FSS/GSO systems severe interference will occur in both directions for short periods (typically 1 minute) several times per day and aggregating to typically 0.2% of the time, unless avoidance measures are taken. It seems unlikely that FSS/GSO users will find such interference acceptable. Of the four possible `avoidance´ alternatives, the authors consider the potential option of reverse-band operation of the non-GSO feeder links to be the most promising