A new digital sense multiple access (DSMA) protocol for high-speed wireless networks

We propose a new digital sense multiple access with delayed transmission (DSMA/DT) protocol for the 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 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. The channel throughput of the DSMA/DT protocol and the optional features are analyzed. Numerical results show a significant improvement of throughput for the new protocol compared to the existing DSMA protocol for non-negligible round-trip delay