Hybrid Energy-Efficient Routing Protocol for Extended Network Lifetime in Wireless Body Area Networks

Wireless Body Area Networks (WBANs) are an emerging technology designed to provide extensive applications in different fields. Healthcare is a particularly interesting field for WBANs. This network plays a vital role in remotely monitoring patients' health conditions anytime and anywhere without interfering with their normal daily activities. In WBANs, sensor nodes are implanted on or inside the human body to detect significant changes caused by abnormal physiological conditions. These sensor nodes can transmit the collected data packets through a sink node to a medical center for analysis, facilitating accurate treatment for patients. However, the energy capacity of sensor nodes is limited. Hence, it is imperative to design and develop a reliable routing protocol to extend the lifetime and achieve load balancing of sensor nodes in WBANs, especially in the healthcare industry. Although many routing protocols have been proposed for WBANs, most of these protocols rely on a single or a few parameters, such as residual energy, hop count, or signal strength to construct routes for transmitting data packets. These parameters are not adequate for selecting the optimal route between the source sensor node and the sink node. Therefore, this paper proposes a hybrid energy-efficient routing (HEER) protocol that overcomes the shortcomings of previous routing protocols for WBANs. The proposed routing protocol introduces a novel route selection function that considers multiple significant parameters, such as residual energy, drain rate energy, energy harvest, distance, priority data, and the participation rate of forwarder nodes in constructing the optimal route. This approach mitigates frequent route failures, extends the lifetime of sensor nodes in the network, and increases the volume of data delivered. Furthermore, a novel hybrid data transmission model and forwarder rotation mechanism are proposed to enhance network performance and load balancing during the transmission of data packets. The experimental results reveal that the proposed HEER routing scheme outperforms existing protocols in various performance evaluation metrics. Specifically, it achieves an improvement of up to 7.64% in packet delivery ratio, increases throughput by 11.08%, and reduces end-to-end delay by as much as 33.74%. Additionally, the HEER protocol significantly minimizes energy consumption by up to 39.98%, thereby extending the network lifetime by 37.04%. These findings validate the protocol's effectiveness in addressing critical challenges in WBANs, including reliable communication, energy efficiency, and extended network lifetime.