On The Energy Efficiency of Adaptive WBAN Systems for mHealth Services

Abstract

We recently proposed an adaptive Wireless Body Area Network (WBAN) system for mHealth service, which shows better bit error performance compared to the non-adaptive one. However, analysis and maximization of the energy efficiency as one of the key design considerations of these networks remain an open problem. Therefore, this paper investigates the energy efficiency of the proposed adaptive WBAN system by considering both the transmission power and the power consumed in the circuitry which consists of rate-independent and rate-dependent components. Since the distance between the hub and the wireless access point in WBAN is relatively short, beside the transmission power, the circuitry power also plays an important role. The adaptive WBAN is evaluated in two different multiple input multiple output configurations. It is found that the adaptive WBAN system substantially outperforms the non-adaptive one in terms of energy efficiency in both 2I1O and 2I2O configurations. Furthermore, the 2I2O adaptive WBAN system is 7.9 dB superior to the 2I1O in terms of energy efficiency. This is because the 2I2O configuration has a higher diversity order and a better array gain compared to the 2I1O configuration, thus the former has better capability to mitigate fading and improve the link reliability. This energy related performance coupled with the improved bit error rate performance suggests that the proposed adaptive WBAN scheme is an attractive physical layer option of a WBAN system for mHealth services. Thus, this scheme could provide not only better quality of services, but also energy saving to enhance the battery life of a WBAN system.

Joint Transmission Power Control and Relay Cooperation for WBAN Systems

“…There are a number of energy consumption models in the literature which can be applied to WBANs, e.g., the models used in [30,50,51,52,53,54,55,56]. However, most of these works do not take the energy consumption of the radio state transition and the energy consumption in sleep mode into account, and the transmission time is simply equal to the time interval allocated to the transmitter.…”

Channel autocorrelation-based dynamic slot scheduling for body area networks

“…Different from other typical wireless radio channels, a large number of factors may result in the severe attenuation (over 100 dB has been observed) in WBAN channels. These factors include diffraction, reflection, energy absorption and consumption, antenna losses, shadowing by the body tissue, and body posture [2][3][4][5][6][7]. It has been demonstrated by many research works, such as [8,9], that the shadowing effect from the human body is the dominant factor that leads to the severe attenuation.…”