SmartBAN With Periodic Monitoring Traffic: A Performance Study on Low Delay and High Energy Efficiency.

The smart body area network (SmartBAN) is a recently proposed system for wireless body area networks (WBANs). Compared to conventional WBANs, it is designed to support lower system complexity and ultralow power consumption. In a SmartBAN, the sensors' access is scheduled upon receiving a beacon on the data channel at the beginning of each working cycle, termed as interbeacon interval (IBI). As network performance, including delay and energy consumption, is highly dependent on the length of IBI, we present, in this paper, an optimal IBI frame for SmartBAN. Our focus is on the delivery of uplink periodically-generated sensor data with low delay and high energy efficiency. As periodic traffic is a common traffic pattern widely generated in e-health applications, for which most previously proposed Markov models for WBANs are inapplicable, a closed-form analytical delay model for periodic SmartBAN transmission is derived. Exploiting this model, a time-optimized framework that minimizes average uplink delay is formulated. An adaptive IBI algorithm is then proposed to determine the optimal IBI during the network connection between hub and sensors. Finally, sleep mode in sensors and doze mode in the hub are introduced to reduce energy consumption under the proposed framework. With optimal IBI, the percentage of energy savings and channel efficiency is evaluated. Simulation and theoretical results show that by using the proposed time-optimized framework, both delay and energy consumption of periodic traffic are significantly reduced. Comparisons with the IEEE 802.15.6 WBAN show performance improvements in periodic uplink delay and energy consumption with our proposed time-optimized framework for SmartBANs.