Wireless Body Area Networks(WBANs) is one of the most attractive communication technologies in recent years. Herein, network lifetime acts as a key factor in various WBANs applications. In this paper, an adaptive energy-aware relay mechanism is proposed to improve the network lifetime performance of WBANs based on the framework specified in IEEE 802.15.6 protocol. The proposed mechanism considers the energy-level of each node in the network to adaptively adjust the topology of the network in order to conserve the nodes which are lack of energy. The mechanism consists of two stages which are initialization phase and update phase. The update phase in the mechanism can be invoked by either enquiry method or report method to efficiently make relay selection for the network and reform the topology according to the varying network conditions. As a consequence, WBANs can make full use of residual energy in the network to improve the lifetime of WBANs. The simulation results show that the proposed mechanism can effectively prolong the network lifetime comparing with the original star topology strategy and other relay mechanisms proposed for WBANs. In addition, a scenario is designed where a sensor node in the network has the ability of moving to illustrate the capability of our mechanism to support mobility of sensor nodes.

无线人体局域网（WBAN）是近年来最有吸引力的通信技术之一。在此，网络寿命是各种WBAN应用程序中的关键因素。本文基于IEEE 802.15.6协议中提出的框架，提出了一种自适应能量感知中继机制，以提高WBAN的网络生命周期性能。所提出的机制考虑了网络中每个节点的能量水平，以自适应地调整网络的拓扑结构，以节省缺少能量的节点。该机制包括两个阶段，分别是初始化阶段和更新阶段。该机制中的更新阶段可以通过查询方法或报告方法来调用，以有效地为网络进行中继选择并根据变化的网络条件重新构造拓扑。因此，WBAN可以充分利用网络中的剩余能量来延长WBAN的寿命。仿真结果表明，与最初的星形拓扑策略和针对WBAN提出的其他中继机制相比，该机制可以有效地延长网络寿命。此外，设计了一种方案，其中网络中的传感器节点具有移动的能力，以说明我们的机制支持传感器节点的移动性的能力。