This invention teaches the use of overlapping footprints in a LEO satellite communications system to increase the overall connectivity of the system, thus providing a wide service availability. In particular, this invention teaches the use of at least one terrestrial LEOS relay station (70) that is positioned within an overlap of at least two satellite coverage areas for relaying a communication from a gateway (18A) associated with a first coverage area to a gateway (18B) associated with a second coverage area. A plurality of LEOS relay stations can be so provided to enable a communication, such as a voice communication, to be routed through a plurality of coverage areas and gateways, thereby bypassing a substantial portion of an underlying terrestrial communication system.

Low earth orbit communication satellite gateway-to-gateway relay system

The double-hop VSAT (very small aperture terminal) network was studied with emphasis on its feasibility and networking in the INTELSAT system. The results of channel-capacity estimation indicate that reasonable channel capacity and availability objectives equal to those for Super IBS (INTELSAT business services) are attainable through the use of the uplink and downlink power control incorporated in the outbound link with BPSK/SCPC (binary-phase shift keying/single channel per carrier) transmission. Possible network architectures for various beam configurations were devised, and the accessibility of individual network architectures was analyzed in terms of blocking probability and call setup time. Based on the results of architecture study, an example implementation of VSAT system is shown. Furthermore, experimental results on the developed VSAT system are discussed. The experiment showed that the transmit power control for the outbound SCPC carrier is conducive to meeting stringent performance objectives stipulated for international digital transmissions. >

T. Honda

Papers

Double-hop networks using VSATs for the INTELSAT system