| 摘要 |
A satellite (S/C) cellular commsystem includes user terminals (UT) for transmitting to, & receiving signals from the S/C, and includes gateways for transmitting to the S/C. The gateways receive and distribute signals from the S/C. Each gateway identifies itself to a UT by use of a location area identity signal, including codes representing (a) the gateway residence country, (b) the system with which the gateway is associated, and (c) the antenna beam on which service is provided. A network controller (NC 18) transmits location area identity codes, representing (a) the identity of the S/C communication system, (b) the satellite carrying the control signal, and (c) the particular antenna beam on which the control signal is transmitted. The UTs store the location area identity signals, and further include a comparator for comparing the identity signals received from the NCC with the stored identity signals. If they are the same, no update is required. If they are different, the UT requests access from the NCC. Upon receiving access, the UT transmits to a gateway the current location area identity, and also updates its own memory, so that at the next turn-on the UT is likely to find that the codes match, and no update is required.
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