Research And Improvement Of WSNs Routing Algorithm Based On Geographic Location

The appearance of Wireless Sensor Networks (WSNs) has caused worldwide concernt, and its application has already rapidly expanded from initial military denfense field to medical treatment, environment science and our daily life. Data multihop transmission and collaboration among nodes are distinct features of wireless sensor networks, so that the design of routing algorithm is a significant research issue, and the routing algorithm based on geographical location information has become reaserch hotspot in recent years because of its excellent scalability and tiny load. On the basis of study about security routing and geographical routing at home and abroad, some innovation work is carried out as follows:Firstly, this paper chooses the Geographical and Energy Aware Routing (GEAR) as research object, and introduces a security Work-based GEAR (W-GEAR) routing based on node doing work reputation evaluation. W-GEAR brings the concept of "work" into WSNs field, adopts Sink confirm mechanism to record data transmission conditions of each node in real time, considers node distances and doing work status synthetically, and comprehensively evaluates reputation value of each node to distinguish hostility attack node. Meanwhile, W-GEAR speculates node energy consumption situation according to node communication behaviors, and identifies malicious nodes lying about residual energy according to testimonies of neighbor nodes. Experimental results under NS2 platform show that W-GEAR could raise the distinguish ability about malicious nodes of routing algorithms based on geographical location by using the above mechanism, and improves the overall security performance of GEAR routing.Secondly, a failure node detection method named Arithmetic Coding based Detection Method (ACDM) and its improved measures aimed at decreasing misjudgement rate are introduced. ACDM takes use of the basic principle of arithmetic coding technique, it adopts an unique certain encoded float number to denote node sequence on data transmission path, and identifies failure nodes on the path. This method does not produce additional detection control information, carries the fixed-size encoded float number in data messages, generates tiny redundant load and computes simply. Simulation results under NS2 show that GEAR routing protocol could detect failure nodes quickly and accurately and position the specific location directly with the ACDM mechanism, and eventually improves reliability and overall performance of geographical algorithms.