Adaptive Priority-threshold Setting Strategy for Statistical Priority-based Multiple Access Network

The statistical priority-based multiple access protocol (SPMA) is a MAC (medium access control) protocol adopted for the Tactical Targeting Network Technology (TTNT), by virtue of high reliability and low latency. In SPMA, in order to keep the network in a favorable loading situation and ensure 99 percent first time success rate for packets of the highest priority, priority thresholds are normally set to fixed values. However, this fixed threshold strategy is not necessarily optimal when the transmission rate at each node varies due to the change of channel condition. To improve the performance, in this paper, we propose an adaptive priority-setting strategy for SPMA, accounting for the change of transmission rates at network nodes. The performance enhancement from the proposed strategy is validated through numerical simulations. In particular, it is shown that higher throughput and lower latency are achieved when the number of nodes supporting high transmission rate increases, while 99 percent first time success rate for the packets of the highest priority is guaranteed when it decreases.