Analysis of CSMA/CA in IEEE 802.15.4

The release of IEEE 802.15.4 medium access control and physical layer specifications, employing carrier sense multiple access/collision avoidance (CSMA/CA) strategies, represents a significant milestone in promoting deployment of wireless sensor networks. In this study, the authors first analyse the performance of the slotted CSMA/CA strategy specified in the contention access period (CAP) of IEEE 802.15.4 by integrating the discrete-time Markov chain models of the node states and the channel states; and then, extend the Markov chain models by adopting a modification to the CAP. The extended models could be used to analyse the performance of the unslotted CSMA/CA strategy specified in IEEE 802.15.4 as well as that of the slotted CSMA/CA strategy. Extensive simulations demonstrate the accuracy and effectiveness of the proposed models and conclusions.