Alleviation of contention collision in IEEE 802.15.4 networks

IEEE 802.15.4 networks employ a medium access control scheme based on carrier sense multiple access with collision avoidance (CSMA/CA). However, CSMA/CA may seriously experience contention collision, suffering from resource wastage in time-varying operation environments. In this paper, we consider the alleviation of contention collision in IEEE 802.15.4 networks by partitioning the transmission period into a number of sub-transmission periods. To this end, the network coordinator and its child devices measure the transmission performance in a distributed manner. When the measured performance is not satisfactory, the coordinator adjusts the number of subtransmission periods considering the operation environment. Each child device uses one of the sub-transmission periods for its signal transmission, effectively reducing the probability of contention collision. Simulation results show that the proposed scheme remarkably reduces packet collision and thus energy consumption in time-varying network environments.