Research And Improvement Of Routing Protocol Based On LEACH For Wireless Sensor Networks

Wireless sensor networks(WSNs) is a hot new research field of computer science. Its basic unit is micro sensor node. A large amount of micro sensor nodes randomly deployed in monitoring area, perceive and collect data collaboratively, then send to terminal user with wireless communication mode. The energy of sensor nodes is limited and the number of nodes is large. There is a need for research a simple and efficient routing mechanism to reduce the energy consumption of nodes, balance the energy consumption of the network and improve the lifetime of WSNs.This paper analyses the classical clustering routing protocol LEACH which is acted as our research object. For LEACH, randomization method used to select cluster heads(CHs) results in a uneven distribution of CHs and a wide fluctuation range of the number of CHs, producing a unbalanced energy consumption of the whole network; And that one-hop communication mechanism applied to data transmission between CHs and the base station(BS) produces huge energy depletion, which is adverse to improving the network lifetime. To overcome these drawbacks, we propose an enhanced multi-hop LEACH protocol based on optimal cluster-heads and region division(called LEACH-OCHRM for short). It makes improvements mainly in two aspects: on one hand, improvement in clustering. Calculate the optimal number of CHs as k, then divide the network into k sub-region each of which contains the same number of nodes. For each sub-region, calculate the coordinate of center of mass. Finally, the high-energy node that is close to center of mass is selected as CH in each sub-region. On the other hand, improvement in communication mechanism, the communication between CHs and Sink is no longer mode of single-hop, but a multi-hop communication link established according to the weight of energy of CH and distance between CH and BS. In this way, the CH far from BS will choose a higher-weight farward CH as the relay node to forward data then to BS finally. All of CHs transmit data to Sink via the multi-hop chain.Take LEACH、LEACH-EE and LEACH-OCHRM as simulate project and simulate performance of these three protocols by Matlab, mainly contrast the performance figure such as topology structure, the number of CHs, the total energy consumption and lifetime of network. The simulation results indicate that the improved LEACH-OCHRM algorithm produces an evener distribution of CHs, balances the energy consumption of the network, greatly improving the performance and lifetime of the network as a result.