TECHNIQUE FOR LEAST COST ROUTING FOR MOBILE SATELLITE SYSTEMS EMPLOYING A GSM NETWORK INFRASTRUCTURE

摘要

A system and method for achieving least cost call routing (i.e. , shortest terrestrial path between mobile terminal and a fixed terminal) for a mobile communications system by integrating a cellular satellite communications system with an existing GSM network to form an extended satellite GSM system and an enhanced satellite GSM system. The extended satellite GSM system incorporates the advantages facilitated by the GSM network with the extended coverage capability of the mobile satellites, and achieves least cost call routing by registering a mobile terminal with one designated gateway (i.e., home gateway). In accordance with another embodiment, the enhanced satellite GSM system achieves least cost call routing for all mobile terminal originated and terminated calls by minor modifications to the mobile terminal and home location register. The resulting arrangement has minimal impact on the GSM network system operation because the modification incorporates standard GSM procedures and protocols and implements data stored at the mobile terminal. Specifically, the resulting arrangement makes no modification to the operation of the mobile switching center or visitor location register (MSC/VLR) used within the GSM network.