Research Of MAC Protocol For Wireless Sensor Networks Based On Power Control Mechanism

With the rapid advancement in wireless communications and microelectronics, the Wireless Sensor Networks(WSNs) are the new-type wireless communication networks have been the focus of research and application. WSNs are composed of a large number of nodes with low cost and simple structure. These nodes are easy to be deployed without any fixture. They can collect information quickly, accurately and comprehensively under a variety of occasions. WSNs make a strong impact on the intercommunion between human and the nature. And they are considered as one of the most important technologies in the 21st century.We focus on the energy consumption, which is the key of MAC protocol. The design of traditional MAC protocols usually focuses on throughput maximizing, latency minimizing and guarantee the fairness of channel access at the same time. As a result of the power limitation in sensor nodes, the MAC design in WSN always put minimizing energy-consumption into the top goal. The existing MAC protocols are classified and both the advantages and disadvantages are analyzed, we mainly focus on the analysis of the competition-based MAC protocols, and have a deeply insight of SMAC and TMAC, which are the most important protocols nowadays.We design a power control MAC protocol for WSN, which is based on SMAC, the optimal power dispatch meter is built in synchronization process of SMAC for each neighbor nodes. By adjusting the transmit power to control the number of neighbor nodes, and node in the maximum optimization of power dispatch table allows it to achieve the target number of neighbor nodes. In addition, the limitation of number nodes optimizes the routing complexity. In the next place, combination the optimal table and the next-hop information make nodes selecting the optimal power to send data by querying optimization power dispatch table, and achieve savings in energy consumption of data transmission.Then the paper used NS2 simulation platform, compare the energy consumption, throughput and time delay of the new protocol and SMAC, and the result shows that the new protocol has a better performance. It can reduce the energy consuming and get improvement on the life of the network. In addition the network delay and throughput have some improvements.