| 摘要 |
RF CHANNEL EXPANSION IN A TRUNKED RADIO COMMUNICATIONS SYSTEM In a trunked radio frequency communications system, an arrangement dynamically "expands" or extends the frequency allocation table stored within the "personality" defining non-volatile storage device of transceivers to include additional RF channels. A channel configuration control message specifying a logical channel field and an FCC channel number defining an RF channel frequency is periodically transmitted over the active RF digital control channel. Transceivers correctly receiving this channel configuration message extend their stored frequency allocation tables to add the additional channel entry specified by the message. The transceivers reference these additional records in response to call messages and are thus capable of operating on the new channels. Channel configuration messages are periodically repeated at time intervals long enough to ensure the messages have no real adverse impact on control channel loading but short enough to cause transceivers to almost immediately update stored channel information. Errors are prevented from occurring by transmitting the channel configuration message in both slots of an outbound control channel message and requiring receipt of a non-zero site identification control message before processing any channel configuration message. |
