Multipath Routing Protocol Design And Implementation Of Wireless Sensor Networks For Environmental Monitoring

Wireless sensor network is a large collection of sensor nodes with limited power si^jply andconstrained computational capability. Due to the restricted communication range and high densityof sensor nodes, packet forwarding in sensor networks is usually performed through multi-hop datatransmission. Therefore, routing in wireless sensor networks has been considered an importantresearch field over the past decade. As people become increasingly concerned about the importanceof environmental issues, the wireless sensor network technology in the ifeld of environmentalmonitoring has become anew hotspot.In order to design robust routing protocol, the paper designs a geographic and energy eiffcientmultipath routing protocol named GEMR.The GEMR protocol is based on the traditionalsingle-path routing protocol GPSR. First, we describe and analyze the GPSR protocoldetailedly.Then,in order to overcome the drawbacks of the GPSR protocol, we propose the GEMRprotocol. GEMR considers the residual energy and the distance to the sink node when setting up theroute. And the GEMR protocol can set up a primary path and multiple alternate paths and adjust thenumber of alternate paths according to the application environment. Finally, in order to solve thecongestion problem,we propose a multipath bifrfer congestion control mechanism MBCC. Thismechanism uses double buffering threshold to detect congestion, and use two methods to avoidand alleviate congestion:decrease transmission rate of the end system and transfer the flow toalternate path.This mechanism can detect and control congestion of GEMR protocol veryeffectively.The Matlab simulation results showed that:compared with the k-MGPSR protocol,the GEMRprotocol can save energy, balance the network energy consumption and prolong the networklifetime.And GEMR outperformace the GPSR protocol in terms of the reliability of datatransmission and network lifetime too.