| 摘要 |
PROBLEM TO BE SOLVED: To mutually communicate between a ground mobile system and a mobile satellite system by bi-directionally communicating with a gate way through a satellite, bi-directionally communicating with a mobile exchange center through a repeater and responding to a protocol of user selection or gate way selection to carry user communication to a ground communication network by first or second transceiver. SOLUTION: A service area is constituted of plural beams or frequencies from a single satellite, or each service area is constituted of the superposing of service areas from plural satellites constituted of one or plural beams. Within the service area 9 of the satellite, a user terminal UT7 and the gate way 10 exist within a ground service area 6, mutually connects UT 7 and a public switching telephone network PSTN 3 by way of at least one satellite 8 through bidirectional satellite links S1 and S2. UT7 is a two-mode terminal and operates in the service are 9 of the satellite or at least one ground service area 2. |
