Energy‐efficient error coding and transmission for cognitive wireless body area network

Summary Wireless body area networks (WBANs) have been developed as human body monitoring systems to predict, diagnose and treat diseases. The two important concerns for WBAN are sensor lifetime and latency. Because the signal transmission in WBAN takes place in or around the human body, the fading and collision of the channel due to other existing wireless devices affect the packet error rate significantly. Hence, the lifetime and latency of the sensor are crucial. To mitigate these problems, a cognitive radio (CR) based WBAN can be a promising solution. In this paper, a cognitive forward error control mechanism for CR‐based WBAN has been presented. Several issues in CR‐based networks have been addressed so far to cope with energy and latency issues. However, the error control mechanism has not been investigated for CR networks. Furthermore, existing studies of the error control mechanism for wireless sensor networks cannot be applied to the CR network because of the opportunistic spectrum access mechanism (i.e. the intermittent availability of spectrum resources). The method presented in this paper adaptively selects the number of hops to the sink and adjusts the redundancy to minimize the expected latency and energy consumption. The mathematical analysis and numerical comparison show that the proposed method achieves better performance in terms of latency and energy efficiency in the multihop CR sensor network. Copyright © 2015 John Wiley & Sons, Ltd. This paper presents a cognitive forward error control (CFEC) mechanism for multihop CR‐based WBAN. The CFEC mechanism selects the best route from source to sink and chooses a suitable error correction code based on hybrid automatic repeat request (HARQ) approach at each hop along the route. The simulation results show the advantages of CFEC in terms of reducing the packet loss, energy consumption and latency as compared to the ARQ and FEC approaches.