Efficient data transmission mechanisms in energy harvesting wireless body area networks: A survey

Limited energy and reliable data transmission are two key issues in Wireless body area networks (WBANs). The utilization of energy harvesting technology has alleviated the energy problem in WBANs, making continuous operation possible. However, Energy Harvesting WBANs (EH-WBANs) face new challenges. How to design efficient data transmission mechanisms taking into account the unstable energy harvesting conditions and dynamic network topology has become crucial. The efficiency of data transmission mainly depends on the network layer and media access control (MAC) layer. Therefore, this paper surveys the routing and MAC protocols proposed for EH-WBANs. There are some surveys on routing and MAC protocols for traditional battery-powered WBANs. However, these mechanisms cannot be directly applied to EH-WBANs due to the randomness and time-varying nature of the energy obtained by energy harvesting, which differs from the energy characteristics of nodes powered solely by batteries. In addition, due to the dynamic network topology and heterogeneous nodes in WBANs, the research results on routing and MAC protocols for Energy Harvesting Wireless Sensor Networks (EH-WSNs) cannot be directly applied to EH-WBANs. Thus, unlike previous surveys, this paper focuses on protocols specifically designed for EH-WBANs. It introduces and analyzes these protocols, summarizes the comprehensive performance metrics and efficient measures for data transmission mechanisms in EH-WBANs, and conducts a comprehensive performance analysis on the protocols proposed for EH-WBANs based on these metrics. This paper intends to provide assistance in addressing the energy and reliable data transmission issues in WBANs, thereby enhancing the applicability of EH-WBANs.