Private land mobile communications has experienced significantdemand for increased capacity and for new services, but congestionwithin the currently allocated 450 and 800 MHz bands has severelylimited the capability of present-generation systems to meet thisdemand. This paper proposes a narrowband integrated voice/data mobileradio system which triples current voice traffic capacity andsimultaneously provides capacity for mobile data communications such asmobile data terminals, automatic vehicle location, and mobile facsimileby utilizing the silence gaps inherent in speech. The system is designedto fit within the narrowband 25 kHz channels in the 450 and 800 MHzfrequency bands and thus the system can replace existing private landmobile radio systems with minimum impact. The centerpiece of the systemdesign is an evolutionary switching technique known as packetized data,voice dedicated (PDVD) burst switching which allows transmission of datawithin the silence gaps inherent in speech. Simulation results forvarious voice and data traffic loads show the flexibility and efficiencyof the proposed narrowband integrated voice/data mobile radio system
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