Enabling Co-Existence of Cognitive Sensor Nodes With Energy Harvesting in Body Area Networks

In this article, we investigate a spectral and energy-efficient wireless body area network (WBAN) for smart healthcare applications. Herein, we primarily focus on improving the spectrum utilization by intelligently sharing spectrum resources through cognitive radio (CR) technology, allowing various sensor nodes in the underlying network to co-exist without compromising on their quality-of-service (QoS). We prioritize the sensor nodes based on their applications (medical/non-medical) and thereby categorize them into primary and secondary users to implement an on-body CR-WBAN. Furthermore, two energy harvesting (EH) protocols namely time-switching cooperation (TSC) and power-splitting cooperation (PSC) are employed to facilitate the secondary node cooperation with the primary network in return for spectrum access. For both the primary and secondary networks, we derive useful expressions for the outage probability. To provide more insights into the proposed CR-WBAN, the throughput and energy efficiency performances assuming a delay-limited scenario are investigated. The impact of key parameters are demonstrated to provide guidelines for the practical design of spectral and energy-efficient WBANs. The accuracy of our proposed analytical framework is verified through Monte Carlo simulations.