Dynamic backoff for wireless personal networks

Based on IEEE 802.15.4 low-rate wireless personal area networks (LR-WPANs), this paper proposes a memorized backoff scheme (MBS) with the exponential weighted moving average (EWMA) approach to dynamically adjust the size of the contention window. The proposed scheme can be implemented in the standard IEEE 802.15.4 medium access control (MAC) protocol without adding any new message type and without modifying the communicating procedure. An analytic model and a simulation model are developed to evaluate the performance of IEEE 802.15.4, MBS and MBS+EWMA. The numerical results indicate that in terms of goodput, completion rate, average MAC delay, average queuing delay and average number of collisions for each data frame, our proposed scheme significantly outperforms the standard IEEE 802.15.4 backoff scheme.