MAC protocol in wireless body area networks for E-health: challenges and a context-aware design

Wireless Body Area Networks (WBAN) is a promising low power technology that enables the communications between body area sensor nodes and a central coordinator. It targets at many applications in e-Health services. In WBAN, different data sources generate time-varying traffic. Large traffic volume may result in intolerant latency and thus it is extremely important that the most significant data can always be delivered in a real-time fashion. Besides, data transmission may suffer from deep fading and packets loss due to the dynamic on-body channel induced by movements and surrounding environment. Hence, energy-efficient medium access control (MAC) is crucially needed to allocate transmission bandwidth and to ensure reliable transmission considering WBAN contexts, i.e., time-varying human and environment conditions. To improve both efficiency and reliability, we investigate the challenges in the development of WBAN MAC design. Furthermore, based on the traffic nature and channel status, we introduce a context-aware MAC protocol to meet time-varying requirements of WBAN. We have demonstrated that the proposed protocol is able to reduce latency, energy consumption, and packet loss rate, as well as to achieve a reasonable trade-off between efficiency and reliability.