Reliable Transmission of Critical Packets in IEEE 802.15.4-based Body Area Networks

Abstract

In this paper, we propose a mechanism to ensure reliable transmission of critical packets in Wireless Body Area Networks (WBANs). As WBANs are responsible for real-time health monitoring, thus, high success rate is necessary in packet transmissions. Especially, packets that possess critical health information must be dealt with utmost priority. To ensure this, in this work we express the probability of successful packet transmission as a function of maximum number of backoff stage - an important MAC parameter - so that we can judiciously tune its value to achieve maximum transmission reliability for critical nodes. The IEEE 802.15.4 is used as the underlying communication standard. We use a simple two-dimensional Markov chain to model the slotted CSMA-CA based channel access mechanism of IEEE 802.15.4, which acts as the basis of the whole work. We compare the proposed approach with random assignment of maximum number of backoff stage to the body sensor nodes and show that judicious tuning of this value yields 25% improvement in reliable packet transmission, in comparison with random assignment.