The Improvement And Research Of Clustering Routing Algorithms In Wireless Sensor Networks

Wireless sensor network (WSN), which is composed of a large number of sensor nodes, is a multi-hop and ad hoc network that is connected by wireless telecommunication technologies. It aims to collaboratively detecting, collecting and processing network information in a certain region and sending the information back to observers through wireless communication. However, Information transmission cannot be separated from the network routing algorithm. Therefore, Routing algorithm is not only a key to ensure the normal operation of the WSN network, but also an important factor to impact of network performance.The design of the routing algorithm in WSN has been mainly studied in order to improve the performance of WSN. The clustering routing algorithm has been selected as the research target purposefully. In this paper, cluster-based routing mechanisms for wireless sensor networks are analyzed. The selection of the cluster head, the formation of the cluster and the routing of the cluster are three key techniques in cluster-based routing algorithms. As viewed from the three techniques, recent representative cluster-based routing algorithms are systemically described, and their characteristics and application areas are compared and analyzed. Based on these cluster-based routing algorithms, a kind of clustering routing algorithm based on the multi-path MPCR has been proposed. The main idea can be listed as followed:Firstly, in the cluster-building phase, MPCR comprehensively considers the residual energy of the nodes, the position of the head nodes of the cluster and the optimal number of the head nodes of the cluster. MPCR uses timers to measure the residual energy of the nodes, which allows the node to become the head node of the cluster if the residual energy of the node is larger than the others by shortening the timing length of the node. Then, the head node of the cluster broadcasts a message in the scope of D and those nodes which receive this message will become a non-head node of the cluster. Consequently, the head nodes of the cluster are distributed uniformly in the network. Secondly, in the routing phase between the clusters, if the head node of the cluster communicates directly with the base station in the routing process between the clusters, it causes those nodes far away from the SINK to dissipate energy fast and results in the uneven distribution of the energy. In order to overcome this problem, researches on the strategy of multi-hop have been largely adopted in the worldwide area, which lead to a "hot spot" problem. So, in order to build a routing table of the next hop for the head node of the cluster, it operates in a way that is to choose a node according to the weigh value of the node. The node will be chosen as the next hop of the routing table if the weigh value of the node is lower than the other nodes. However, when the changing range of the node energy exceeds the thresholdΔE, the routing table of the next hop for the node would be refreshed, through deleting the routing nodes which have become the "hot spot" . Then, every head node of cluster has several paths that are multi-hop to communicate the data to the SINK. Therefore, it not only realizes the routing of the multi paths, but also solves the "hot spot" problem in multi-hop.Finally, the simulation of three cluster-based routing algorithms that is LEACH, EEUC and the algorithm provided in the paper MPCR has been implemented. The result shows that the improved algorithm MPCR performs better than LEACH, EEUC in terms of network lifetime, network energy consumption and balance of the death of nodes.