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The technological advancements in wireless communication and miniaturization of sensor nodes have resulted in the development of Wireless Medical Sensor Networks (WMSNs) which can be effectively used for remote patient monitoring. Remote patient monitoring is one such application of wireless sensor networks which is becoming increasingly prevalent in healthcare. The healthcare applications of the WMSNs are delay-sensitive and require timely delivery of patient-critical data. However, the frequent exchange of critical data packets results in higher delays, collisions, packet drop, and re-transmissions. Consequently, it brings a detrimental impact on the performance of the WMSNs. In addition, the implanted biomedical sensor nodes produce electromagnetic radiations, pose a serious threat of damaging sensitive tissues in the human body. Protecting tissue damage requires thermal-aware routing protocols. However, most of the thermal-aware routing protocols developed for the WBSNs primarily focused on minimizing temperature, while overlooking the energy conservation goal and optimization of route selection. In this paper, we propose a weighted, QoS-based, energy and temperature-aware routing protocol, referred to as (WETRP), for the WMSNs that utilizes a composite routing metric by keeping in view temperature, remaining node energy, and link-delay estimation during route selection decisions. The simulation results presented in the paper demonstrates the efficacy of the proposed scheme in terms of preventing temperature rise, dealing with hotspot nodes, and maximizing network's lifetime. INDEX TERMS Wireless body sensor network, routing protocols, QoS, energy efficiency, temperature, hotspot nodes.

Wireless Body Sensor Networks (WBSNs) are becoming increasing popular in a number of healthcare applications. A particular requirement of WBSNs in a healthcare system is the transmission of time-sensitive and critical data, captured by heterogeneous biosensors, to a base station while considering the constraints of reliability, throughput, delay and link quality. However, the simultaneous communication among various biosensors also raises the possibility of congestion on nodes or transmission links. Consequently, the likelihood of a number of untoward situations increases, such as disruption (high delays), packet losses, retransmissions, bandwidth exhaustion, and insufficient buffer space. The significant level of interference in the network leads to a higher number of collisions and retransmissions. The selection of an optimized route to cope with these issues and satisfy the QoS requirements of a WBSN has not been well-studied in the relevant literature. In this regard, we propose a multi-constraint, Intra-BAN, QoS-Aware Routing Protocol (referred to as MIQoS-RP) which introduces an improved, multi-facet routing metric to optimize the route selection while satisfying the aforementioned constraints. The performance of the proposed protocol is evaluated in terms of average end-to-end delay, throughput and packet drop ratio. The comparison of MIQoS-RP with the existing routing protocols demonstrates its efficacy in terms of the selected criteria. The results show that the MIQoS-RP achieves improved throughput by 22%, average end-to-end delay by 29% and packet drop ratio performance by 41% as compares to existing schemes.

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The Wireless Body Sensor Network (WBSN) can be envisioned as a cost-effective solution to provide monitoring and reporting services in medical and non-medical applications to improve quality of life. The dissemination of patient data in a timely and reliable manner is one of the necessities of healthcare applications of WBSN. The critical data packets are highly delay-sensitive. However, these packets reaching the destination beyond timelines undermine the benefit of such networks. To provide real-time health monitoring an adequate link (in terms of reliability, stability, and QoS) has to be maintained. However, the distinguishing characteristics of WBSN pose several challenges to be countered such as limited resources, transmission range, and unreliable wireless links in terms of QoS as low-power radios are sensitive to interference and noise. Consequently, some portions of the network experience a significant level of congestion thereby strain the communication links, available bandwidth, insufficient buffer space, increased number of collisions, packet losses, and transmission disruption. Therefore, importing QoS awareness in routing decisions is important to improve the performance of WBSN. This paper proposes a QoS-aware routing protocol named TLD-RP (Temperature, Link-reliable, and Delay-aware Routing Protocol) for WBSN. Most of the temperature-aware routing protocols proposed for the WBSN incorporate either single or composite routing metrics (temperature, hop count, or energy). However, optimized route discovery has been overlooked in most of the previous studies on QoS requirements such as link reliability, stability, and link delay. Keeping in view these limitations, the proposed TLD-RP makes use of a multifacet composite routing metric by carefully considering the critical QoS requirements for the WBAN. The design of the proposed TLD-RP scheme centers on the link's reliability, path delay, and link's asymmetric property. These design factors enable the proposed TLD-RP scheme to make more informed decisions regarding dynamic channel conditions. The optimized links satisfying the QoS requirements are selected for routing data packets. The simulation results confirm the effectiveness and efficacy of the proposed TLD-RP strategy by improving WBSN performance along with throughput, packet delivery, network overhead, and link stability.