Adaptive Backoff Control Method for Traffic Adaptive Active Period Control in Cluster-Based IEEE 802.15.4 WSNs

The traffic adaptive 2-level active period control has been proposed for performance enhancement in cluster-based wireless sensor networks (WSNs) employing IEEE 802.15.4 medium access control (MAC) under temporal and geographical non-uniform traffic distribution. This paper proposes an adaptive backoff window control method for the traffic adaptive 2-level active period control. The proposed method adjusts the backoff window size according to the length of current active period, which is determined by the 2-level active period control, and the point of channel access in the active period and the elapsed time for transmitting packets. The results evaluated by computer simulation show that the proposed method can improve the throughput performance as well as energy efficiency in the cluster-based WSNs with non-uniform traffic distribution.