The Design Of Energy-saving MAC Protocol Of WSN

Wireless sensor networks (WSN) is composed of massive, small sensor nodes which are deployed in monitoring region, the target of which is to cooperatively sense, collect and process the information of object in the coverage area, then through wireless communication sending to the observer. It can be widely used in military applications, medical treatment, traffic, environment monitoring and so on.The energy of the WSN is supplied by the battery, the energy is limited and can't be replaced. In order to prolong the lifetime of WSN, we must consider the Energy-saving technologies. So in this paper, we focus on the energy consumption, which is the key of MAC protocols. We design a MAC protocol for WSN, which is base on S-MAC and adapts to small-scale monitoring network and designs simulation experiment. S-MAC can achieve low duty cycle through periodical sleep, in order to saving energy, in this paper we designs a dynamic duty cycle which can adjust duty cycle of nodes in time. Meanwhile, in order to avoiding nodes collision, S-MAC use BEB backoff strategy, but this strategy brings unfairness. In this paper, we use MILD backoff strategy instead of it, and reduce unfairness.In this paper, we use NS-2 to simulate and test the improved protocol. Through the analysis and the simulation results, we can see that, in contrast with S-MAC, the improved MAC protocol improves energy savings, the mean throughput, and delay, etc.