On The Energy-efficient Adaptive MAC Protocol For Wireless Sensor Networks

Wireless sensor network is a novel technology for acquiring and processing information, which is made by the convergence of wireless communications, sensors, nested computation, and network technologies. It is a typical wireless network without infrastructure, and it can be used for testing, sensing, collecting and processing information of monitored objects. It can be applied in many areas such as military affairs, commerce, medical care, and environmental monitoring, which has attracted much attention to both academia and industries.It is the objective of this thesis to investigate the MAC protocols with high energy efficiency. In wireless sensor network, the numbers of sensor nodes is huge, and the resource is very limited for a single node. One of the most important tasks of MAC protocol in wireless sensor network is to reduce the energy consumption in the network. The author analyzes some MAC protocols, assimilates good ideas from S-MAC, an improved energy-efficient adaptive MAC, named A-MAC is proposed.In heterogeneous environment, there are many different traffic types in end-nodes or relay nodes, all occurring with different probability and at different time, which is in fact the target of A-MAC protocol. In A-MAC, by adjusting duty cycle in the frame of the protocol, one can reduce the energy consumption as much as possible with almost the same throughout. The A-MAC protocol let a node to sleep longer time than S-MAC, to support the situation of heterogeneous nature of traffic.Based on the simulation results of A-MAC, S-MAC, and 802.11 with the help of OPNET, it is shown that the A-MAC protocol has advantage in energy-saving, compared with S-MAC and 802.11, especially in heterogeneous and variable of traffic.