A narrowband, high capacity integrated voice/data mobile radio system for dispatch-related broadcast applications

This paper presents the design and performance analysis of a narrowband, mobile radio system optimized for dispatch-oriented broadcast applications in the 450 and 800 MHz frequency bands. The proposed system is significant since present-generation systems have proven incapable of providing the increased capacity demanded by new data services such as mobile data terminals, automatic vehicle location, and mobile facsimile. The centerpieces of the proposed design are a dynamic multiplexing technique known as packetized data, voice dedicated (PDVD) burst switching, which allows transmission of data within the silence gaps inherent in speech, and a noncausal signal processing technique called lookahead, which provides the data sources with advance knowledge of where the silence gaps will occur. Simulation results are given for two dispatch-oriented broadcast applications with widely differing traffic statistics, showing the flexibility and efficiency of the proposed system. The results show that for either application, the proposed integrated voice/data system can be retrofitted into existing 450 and 800 MHz public and private land mobile radio channels and, compared to conventional voice-only systems, can provide the user with full data services plus a tripling of voice capacity