A CSMA/CA Based MAC Layer Solution for Inter-WBAN Interference and Starvation

Abstract

With the advancement in wireless communication technologies, E-healthcare system has been proposed to deal with the issues such as inefficiency, high cost, and degradations in service quality in traditional health-care systems. Wireless Body Area Network (WBAN) is widely used in E-healthcare system as it provides continuous monitoring on physiological parameters. However, when two or more WBANs overlap with each other, there exists inter-WBAN interference. The inter-WBAN interference may cause transmission failures, which result in packet losses, throughput degradations, and energy wastes for energy limited sensors. This motivates us to develop a distributed CSMA/CA-based MAC protocol for inter-WBAN interference management. There are three challenges, namely, power optimization, protocol response time, and starvation in designing such a protocol. In this thesis, the power optimization challenge is overcome by an innovative WBAN system. To deal with the challenges in protocol response time and starvation, the proposed MAC protocol extends the CSMA/CA protocol with an adaptive transmission probability that uses frozen time as the adjustment criterion and a back-off counter adjustment mechanism that prioritizes the starving nodes. The proposed protocol achieves throughput improvement, starvation mitigation, and energy efficiency for sensors. Simulation results demonstrate the effectiveness of the proposed MAC protocol for health-care applications in scenarios such as having dinner at a round table or sitting in a hospital waiting room