The Research Of Energy Saving Strategies For Wirelesssensor Networks

Wireless sensor network is composed of many tiny sensor nodes which deployed in certain monitoring area. As the size of node is very small, the carried battery energy is limited. Besides, nodes usually deployed in danger area, so people usually do not replace the battery even though it is run out of energy. Thus, the energy consumption problem is one of the most important problems we need to consider when deploy a wireless sensor network. After being proposed, the IEEE 802.15.4 standard has been widely used in wireless sensor network as its feature of low-energy consumption and low-bitrate. Based on the IEEE 802.15.4 standard, this paper improves the standard from the view of the sender and the receiver respectively to prolong the lifetime of wireless sensor network.From the sender’ view, This paper presents a Markov chain model and then derives the probabilities of the idle, backoff, send, collision, Clear Channel Assessment(CCA) state of node and by the above probabilities to build the indexes of energy consumption and throughput, especially analysises the influence for the sensor network node adapts the different contention window increase size according to the number of contention nodes and finds an optimal value to optimize the throughput and energy consumption.Then proposes a adaptive energy-saving broadcast algorithm.Nodes adaptively adjust broadcast interval according to the competition level in the channel.if the competition level lager than the given value in advance,increase the broadcast packet interval;otherwise decrease the broadcast packet interval.