A Priority-Based MAC Protocol for Energy Consumption and Delay Guaranteed in Wireless Body Area Networks

Wireless body area networks (WBANs) consist of tiny sensors that placed around or implant in the human body. These nodes can permanently monitor the health of patients. WBANs require medical applications for remote monitoring and health care. In WBANs, the main challenge is delay and limitations of energy consumption to prolong the network lifetime. In this context, a MAC protocol has been provided to guarantee energy consumption and delay reduction based on priority of data traffic. The design of this protocol consisted of four sections: First, the patient data traffic is prioritized and classified, which included normal data, periodic data, and emergency data. Second, the superframe structure is improved according to IEEE 802.15.4 and the priorities for the data are optimized. Third, the energy consumption and delay have been reduced by using the radio wake-up mechanism and through controlling the node modes. Four, for checking the node modes, the state diagram and the asymmetric hidden Markov method have been exploited to model the limited capacity of the buffers. This protocol has been simulated using NS-3, and simulation and evaluation results indicated that lower energy consumption and delay as well as improved network lifetimes compared to the previous methods.