Retransmission Adaptive Intelligent MAC (RAI-MAC) for Wireless Body Area Networks

Abstract

Wireless body area networks (WBANs) technology has emerged in recent years as a subcategory of wireless sensor network technology targeted at monitoring physiological and ambient conditions surrounding human beings and animals. WBAN technology allows building wireless sensor networks in, on, or around the human body. WBAN is not only used in medical applications but also has non-medical applications. Medical applications are Physiological and vital signals monitoring, medical stimulators and remote control of medical devices and non-medical applications includes entertainment and military. A WBAN uses body sensor to transmit and received wireless communication. WBAN has recently emerged as one of the premier research topics in enhancing healthcare industry. IEEE 802.15.4 MAC protocols are subject to frequent collision and therefore transmission failure due to frequent and rapid traffic generation to report certain important event. There frequent collisions effect the delivery ratio, end-to-end delay and energy efficiency. Several retransmission schemes have been proposed in literature in order to address the issue of failed transmission due to collisions. However majority of the retransmission schemes allow sensor nodes to immediately retransmit which may cause more collisions and also do not consider the number of failed transmissions by sensors nodes and effect the fairness and reliability of retransmissions. In this thesis we propose an efficient and adaptive retransmission scheme called RAIMAC to retransmit the failed frames adaptively according to the number of failed transmissions. The proposed scheme not only increases probability of frame retransmission, but also increases the fairness among sensor nodes. Simulation results prove that our proposed scheme RAI-MAC significantly improve throughput and end-to end delay.