A New Digital Sense Multiple Access (DSMA) Protocol for High-Speed Wireless Networks

In this paper, we propose a new Digital Sense Multiple Access with Delayed Transmission (DSMA/DT) protocol for reverse channel in high-speed wireless networks. The new protocol is motivated by the observation that the existing DSMA protocol does not yield satisfactory throughput for long round-trip propagation and processing delay, which occurs in outdoor, high-speed environments or when the receiver hardware requires long signal processing time. The new DSMA/DT protocol is intended to reduce the performance impacts of the round-trip delay. Several optional features: look-ahead busy/idle flag, seizure queueing and reserved time slots are also devised for the new protocol. While requiring at most two additional status bits on the forward channel and no additional hardware capability, these features further enhance the protocol performance, and enable constant-bit-rate service with little added complexity in control. The channel throughput of the DSMA/DT protocol and the optional features are analyzed. Closed-form expressions for the throughput are obtained. Our numerical results show a significant improvement of throughput for the new protocol compared to the existing DSMA protocol for nonnegligible round-trip delay relative to packet transmission time. For the superior performance and simplicity, the DSMA/DT protocol will be appropriate for use in high-speed wireless networks. Subject Area: Multiple Access Methods ________________ * Please forward correspondence to Kin K. Leung at his address, or by email [email protected], phone (732)345-3153 and fax (732)345-3038.