Research On Hierarchical Routing Algorithm For Wireless Sensor Networks

Wireless sensor network is a multi-hop and self-organizing network system, where a large number of sensor nodes are deployed in a monitoring area and they communicate with each other through a wireless way. As a new method for information collecting and processing, wireless sensor network has been widely used in environmental monitoring, biological and medical treatment, intelligent home furnishing and other fields. However, the nodes in a sensor network usually use the micro battery which provides severely limited energy, plus that the nodes are difficult to retrieve after been deployed, so the routing protocol has become one of the core technology of wireless sensor networks, its performance will directly affect the efficiency of the whole network.In recent years, research on routing protocols for wireless sensor networks have made many achievements, but there still exist many problems to be solved, such as "hot spots","energy hole" and so on. They are caused by unbalanced network load and network topology. How to realize the load balance of nodes within the network and prolong the network life cycle have become a great challenge and significant research in wireless sensor networks.This paper focus on the theme about wireless sensor routing technology research, specifically the hierarchical routing in the hot spots and the energy hole problem. For the two problems, this paper puts forward some load balanced hierarchical routing algorithms.1. For the "hot spots" problem resulted from unbalanced nodes energy consumption in wireless sensor networks, we, on the basis of the existing hierarchical routing protocols, put forward a LDUC algorithm that is based on node location and density of non-uniform clustering routing algorithm. In the phrase of cluster head election, the algorithm takes the residual energy of nodes into account, and introduces competition mechanism for cluster head selection. In the clustering phase, we consider the distance between node and the base station and the node density for non-uniform clustering. thus we can achieve the node energy balance and solve the problem of routing hot region. During the inter-cluster routing stage, through the establishment of communication cluster head nodes, the data forwarding task is separated from the cluster head nodes. The cluster head node is responsible only for intra cluster data collection and fusion, and the communication cluster head nodes are responsible for the data transmission between the clusters. By doing this, the cluster head energy consumption is reduced.2. Aiming at the inter-cluster multi-hop communication in the hierarchical routing algorithm for wireless sensor networks, which is easy to form the "energy hole" problem, we propose a low-power and hierarchical routing algorithm for wireless sensor network-LHRA. This algorithm takes the node location into account, and introduces the network partition method. The whole network is divided into several layers. In each layer, we select cluster head nodes and cluster nodes, so that the distribution of cluster head nodes is more reasonable. The factors of node residual energy and node density are combined in the cluster head selection. This method is applicable even when the nodes are distributed non-uniformly. In inter-cluster routing establishment phase, the multi-path selection mechanism is adopted to balance the inter cluster communication energy consumption. This algorithm is effective to avoid the energy hole and to prolong the network life cycle.The hierarchical routing algorithms for wireless sensor networks are complex."hot spots" and "energy hole" is just one of the hot researches. This thesis just made some analysis and exploration on the basis of many predecessors’researches. There are also a lot of issues need to be resolved for future research.