In this paper, a Stable, Thermal-aware and Energy-efficient routing Protocol (STEP) is proposed for Wireless Body Area Networks (WBANs) that not only deals with the thermal aspects and hot-spots problem but also saves energy and extends the stability period and network lifetime. Direct communication is used for real-time traffic (critical data) while multi-hop communication is used for normal data delivery. In multi-hop communication to achieve minimum power consumption and minimum temperature rise, the proposed protocol has a new cost function using multi-criteria decision making MCDM methods to determine the parent node or the forwarder. These methods provide a flexible decision-making process for selecting the next hop by considering different criteria at the same time. The proposed cost function has three criteria: residual energy, distance to the sink node and temperature. Residual energy criterion balances the energy consumption among the sensor nodes while distance criterion ensures successful packet delivery to the sink node and minimize the energy that will be consumed, the temperature criterion will avoid routing across hot nodes to protect the tissues. The simulation results show that the proposed protocol preserves the energy and increases the network lifetime & stability period so nodes stay alive for a longer period. A longer stability period contributes significantly to the delivery of packets, which is very important for continuous patient monitoring. Results also depict that the proposed protocol can achieve a better balance of the temperature rise comparing to the previous protocols.

Wireless Body Area Networks (WBANs) Routing protocols in WBANs Multi-Criteria Decision Making (MCDM) Methods AHP method SMART method WSNS.