Energy Efficient Transmission Approach for WBAN Based on Threshold Distance

Abstract

Energy efficiency is a key concern for wireless sensor nodes, especially for wireless body area network (WBAN) in which sensors operate in close vicinity to, on or even inside a human body. In this paper, we first present a system-level energy consumption model associated with transmission distance $d$ and transmission data rate over on-body wireless communication link. Then, based on the analysis of tradeoff between circuit energy and transmission energy on distance, a threshold distance $d_{\rm th}$ which is responsible for the proportion of transmission energy and circuit energy is derived for energy saving in WBAN. With the case of $d\leq d_{\rm th}$ , since circuit energy is comparable with transmission energy consumption, the total energy consumption can be saved by optimizing the transmission data rate $R$ . Simulation results show that a 59.77% or even more energy saving is achievable using the optimized scheme, compared with baseline scheme. With $d>d_{\rm th}$ , since the total energy consumption is monotonically decreasing with respect to time $t$ , an offline algorithm is applied to energy saving by prolonging transmission time within the deadline time. In addition, on the basis of the offline algorithm, a battery-aware transmission approach is presented for WBAN using battery electrochemical property. Experimental results show that, using the presented battery-aware approach, 71.05% and 60.81% energy saving can be obtained, in comparison with the baseline and offline schemes, respectively.