| 摘要 |
A land mobile radio communication system has a plurality of cell sites, each of which typically has a plurality of repeaters. The over-the-air radio communications between the cell site repeaters and the mobile radios in the system include both a voice component and a data component. The data component is carried as low-frequency subaudible information. Communication channels are provided between the radio users at each site as well as between users at different sites and between mobile radio users and the public telephone network. Within a cell site, the transmitted and received communicatios are digitized and passed through serial buses in a time multiplex fashion. The digitized voice is transferred between time slots to provide the required switching function. The system includes operational software to provide direct inward dial telephone number recognition, automatic voice prompts for a user entering a new cell, call priority override, fraud control for radio fleets and a dynamic control channel.
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