The Energy Efficiency Optimization In MAC Protocol Of Wireless Body Area Network Based On The Priority And The Sleep Mechanism

ABSTRACT:Wireless Body Area Network is a new generation of wireless networks, which has a very wide range of application in the medical, rescue, military and other fields. Sensor node is the main component unit, through which collecting, processing and transmitting data information. Sensor node is usually powered by battery, whose energy is very limited, and therefore, reducing the energy consumption of sensor node to extend the life cycle of the wireless body area network becomes very critical. In the wireless body area network, the media access control (MAC) protocol decides the allocation of limited wireless channel resources of sensor nodes, which has an important influence of the performance of the wireless body area network.Therefore, the study of designing low-power MAC protocol to improve the performance of wireless body area network has a very great sense. The thesis will optimize the MAC protocol of wireless body area network respectively from the angles of setting priorities and sleep mechanism.First of all. the research background and key technologies of wireless body area network are first introduced in this paper, the state of the wireless body area network MAC protocol research and principles of designing MAC protocol are analyzed, and then the thesis mainly introduces the wake up radio MAC protocol, in which low cost wake up radio module attached with sensor node controls the sleep and wake of the sensor nodes. Furthermore, the thesis optimizes the MAC protocol through setting priority of the type of services and sensor nodes, and aslo simplifying the process of data transmission in emergency operations, the optimized MAC protocol based wake up radio has been proved to reduce the energy consumption of wireless body area network to improve the energy efficiency of the network.In the second place, the thesis optimizes the traditional sleeping mechanism commonly used in the current MAC protocols of wireless body area network. In this paper, Markov chain stochastic model is established, energy consumption and time delay cost matrix are also introduced. And then, The optimization strategy is got through the using of linear programming to solve the optimization problem with constraints, in which, the minimum of energy consumption has been achieved. It is the optimization strategy that determines the sensor node activating or entering the sleep state at the next time. In this way, energy consumption of sensor node is decreaseed by preventing frequently switching in active and sleep state, consequently, getting a lower power consumption and prolonging the lifetime of the node sensor, advancing the performance of wireless body area network.Finally, the thesis draws conclusions by summarizing situation of wireless body area network MAC protocol and by presenting directions for future work.