Department of Computer and Software Technology, University of Swat, Swat 19130, Pakistan.
Department of Information Systems, College of Computer and Information Sciences, King Saud University, Riyadh 11543, Saudi Arabia.
Sensors (Basel). 2020 Apr 22;20(8):2368. doi: 10.3390/s20082368.
The IEEE 802.15.6 standard has the potential to provide cost-effective and unobtrusive medical services to individuals with chronic health conditions. It is a low-power standard developed for wireless body area networks and enables wireless communication inside or near a human body. This standard utilizes a Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol to improve network performance under different channel access priorities. However, the CSMA/CA proposed in the IEEE 802.15.6 standard has poor throughput performance and link reliability when some of the nodes deployed on a human body are hidden from each other. We employ the RTS/CTS scheme to solve hidden node problems in IEEE 802.15.6 networks over a lossy channel. To improve performance of the RTS/CTS scheme, we adjust transmission power levels of the nodes according to transmission failures. We estimate throughput and energy consumption of the proposed model by differentiating several parameters, such as contention window size, values of bit error ratios, number of nodes in different priority classes. The performance results are obtained through analytical approximations and simulations. We observe that the proposed model significantly improves performance of the IEEE 802.15.6 CSMA/CA by resolving hidden node problems.
IEEE 802.15.6 标准有可能为患有慢性疾病的个人提供经济高效且无干扰的医疗服务。它是一种为无线体域网开发的低功耗标准，能够在人体内部或附近进行无线通信。该标准利用带有冲突避免的载波侦听多路访问（CSMA/CA）协议，根据不同的信道访问优先级来提高网络性能。然而，当人体上部署的一些节点彼此隐藏时，IEEE 802.15.6 标准中提出的 CSMA/CA 协议的吞吐量性能和链路可靠性较差。我们在损耗信道上的 IEEE 802.15.6 网络中使用 RTS/CTS 方案来解决隐藏节点问题。为了提高 RTS/CTS 方案的性能，我们根据传输失败情况调整节点的传输功率级别。我们通过区分几个参数（例如争用窗口大小、误码率值、不同优先级类别的节点数量）来估计所提出模型的吞吐量和能耗。通过分析近似和仿真获得性能结果。我们观察到，所提出的模型通过解决隐藏节点问题，显著提高了 IEEE 802.15.6 CSMA/CA 的性能。
