Performance Analysis of Time-Critical Peer-to-Peer Communications in IEEE 802.15.4 Networks

Existing works on the performance analysis of IEEE 802.15.4 networks with peer-to-peer (P2P) topologies assume the non-beacon unslotted mode in the MAC layer, which is not suitable for time-critical communications required by many applications, such as control, actuation and monitoring applications. In this paper, we introduce an enhanced guaranteed timeslot (GTS) mechanism which can support time-critical P2P communications in wireless sensor networks (WSNs). A Markov chain that takes into account retransmission limits, acknowledgements, unsaturated traffic and packet delivery ratios of links is proposed to model P2P communications using this enhanced GTS mechanism. Based on this model, we analyze the expected reliability and energy consumptions under various traffic conditions. In addition, the impacts of MAC parameters on these performance indexes are analyzed. Monte Carlo simulations show that our theoretical analysis is quite accurate, and thus can be used as guidance for networks configuration in WSNs.