Urgency-Based MAC Protocol for Wireless Sensor Body Area Networks

In this paper, an Urgency-based MAC (U-MAC) protocol, in which sensor nodes reporting urgent health information are given higher priority by cutting-off the number of packet retransmission of sensor nodes with non urgent health information, is proposed. The main consideration of this work is providing Quality of Service (QoS) support in medical wireless sensor networks through differentiating nodal access to the medium. The proposed MAC protocol is mathematically analyzed considering a beacon-enabled star network configuration of the IEEE 802.15.4a standard at 2.4 GHz. The used wireless body area network (WBAN) consists of N sensor nodes controlled by a single network coordinator. The obtained performance results show the capability of the proposed UMAC protocol in providing service differentiation in medical WBAN. Also, the results show that the number of critical nodes that can be supported by WBAN and their packet arrival rates decrease as the number of packet retransmission of such nodes is increased.