Performance evaluation of IEEE 802.15.4 MAC with synchronization-loss based on Discrete-time Markov Chain

Wireless sensor networks (WSNs) are normally assumed to be synchronized (in Syn-mode). However, nodes may lose synchronization, and therefore, will work in Syn-lost-mode before potentially re-synchronizing. This procedure brings poor performance to the network. This paper evaluates the impact of losing synchronization in beacon-enabled IEEE 802.15.4 network with star topology. Discrete-time Markov-Chains (DTMC) are proposed to investigate the impact of three scenarios which lead to Syn-lost-mode. These scenarios are node identification (ID) conflict, realignment failure and a certain number of times of continuous beacon-loss. To the best of our knowledge, this is the first work on Syn-lost-mode performance in synchronized IEEE 802.15.4 networks. The performance is investigated in terms of the network throughput, time delay, packet delivery ratio and energy consumption. Simulation also verifies our work and demonstrates the poor network performance due to synchronization-loss.