Energy-Efficient and QoS-Aware Link Adaptation With Resource Allocation for Periodical Monitoring Traffic in SmartBANs

Limited energy resources of sensors and stringent quality-of-service (QoS) constraints in biomedical applications raise serious concerns when utilized in Wireless Body Area Networks (WBANs). The European Telecommunications Standards Institute (ETSI) Smart Body Area Network (SmartBAN) represents a standardized communication interface and protocol between a hub coordinator and a set of sensors, that has been designed with simplicity and low power in mind. This work presents an ETSI SmartBAN PHY and MAC configuration framework that remarkably lengthens sensors battery lifespan through reducing transceivers consumed energy. To that end, and taking into account the channel quality and packet error rate requisites of sensors, a mechanism to select between the different PHY transmission modes of the standard is proposed. This link adaptation scheme is combined with a resource allocation algorithm that derives the duration of the inter-beacon intervals and the transmission periods of sensors, while fulfilling traffic delay constraints and minimizing sensors transceivers energy consumption. Analytical expressions for packet error rate of all available PHY transmission modes, as well as for traffic delay, transceivers energy savings of hub and sensor nodes, and battery duration, are derived. Computer simulation results substantiate the efficacy of both, the presented QoS-aware adaptive transmission scheme and the resource allocation algorithm, in fulfilling the target packet error rate and delay requirements, while significantly expanding the battery duration, specially for sensors with long elapsed times between successive sensing intervals (up to a 515% increase and a 960% increase are obtained for the two considered simulation scenarios).