Low Control Overhead Of The Wireless Sensor Network Mac Protocol Research

Wireless sensor network(WSN) is an integrated intelligent information system, which can process and transmit the gathered information. Wireless sensor network is composed of large number of densely distributed sensor nodes. Each sensor node has limited energy, processing ability and small storage capacity. In order to guarantee the network long-term and effective work, it is important to allot the wireless medium reasonably on the basis of the energy efficient. In this paper,we proposed two low overhead protocol-LO-MAC and (LN)LO-MAC based on S-MAC protocol. Both of the protocols can decrease the control overdead and prolong the network lifetime.S-MAC protocol is a typical WSN MAC protocol, it adopts listen and sleep mechanism to avoid energy consumption. The energy consumption of distributed synchronization in S-MAC can be decrease though centralized synchronization. And the synchronization mechanism of S-MAC protocol will lead to the generation of border nodes, which decrease the network lifetime and connectivity. LO-MAC protocol decreases the nodes listen time and transmission of synchronization information to reduce the energy consumption and extend the network lifetime. In addition, the centralized synchronization of LO-MAC averts the appearance of border nodes. The simulation of LO-MAC and S-MAC on NS2 proved that LO-MAC protocol has longer network lifetime.Due to the coverage area of LO-MAC protocol is restricted by the transmission range of sink node, and accordingly, we proposed a low overhead MAC protocol suitable for large network, that is, (LN)LO-MAC protocol. This protocol makes all of nodes in the network adopt unified scheduling to decrease the overhead of synchronization though the coorperattivework of multiple sink nodes. The advantage of energy efficient was verified though the simulation of (LN)LO-MAC and S-MAC on NS2, and (LN)LO-MAC protocol applys to the large metwork.