An adaptive contention control strategy for IEEE 802.15.4-based wireless sensor networks

The IEEE 802.15.4 standard is able to achieve low-power transmissions in low-rate and short-distance wireless personal area networks (WPANs). Due to the constitutional design of the sensor node and the transmission architecture (clientserver model), any data communication between two sensor nodes will involve the coordinator. One shortcoming of redundant channel-access steps will result in excessive contention overheads and, thus, the decrease of channel utilization. This paper proposes an adaptive contention control strategy (ACCS) to solve the problem of transmission efficiency in IEEE 802.15.4. ACCS can be implemented in the IEEE 802.15.4 medium access control (MAC) protocol standard adding no new message type. An analytic model and a simulation model are developed to evaluate the performance of IEEE 802.15.4 and ACCS. The simulation results demonstrate that the proposed scheme significantly improves the goodput, the average queuing delay, the average MAC delay, and the energy consumption.