Laser Crosslink Configurations for RF Satellite Communications Systems

Predictions of future satellite communications traffic indicate an increased capacity for satellite communications systems is required. Crosslinks between satellites provide improvements in communications throughput for these systems. Crosslinks also increase system flexibility and remove the dependence of world-wide information flow on relay ground stations located outside the continental United States. Laser crosslinks provide the additional advantage of eliminating susceptibility to space-based or ground-based jammers. Laser terminals are also smaller and require smaller antennas than a radio frequency (RF) terminal. This paper describes the advantages of adding laser crosslinks to RF satellite communications systems. Characteristics of the required RF/optical interfaces on-board the satellites are addressed. Terminal configurations that provide reliable, accurate laser communications at high data rates are described.