A Routing Protocol Based On Hierarchical Chain-Tree For Wireless Sensor Network

With the rapid development and increasing maturity of sensor techniques, embedded computing techniques, micro-electro-mechanical systems and wireless communication techniques, wireless sensor networks (WSN) were emerged gradually. In WSN, a large number of sensor nodes can implement data sensing, collection and processing together in monitoring region, and then the data is transmitted to the sink by way of multi-hop relay. WSN is a new information acquisition and processing technique, it can be widely applied in many areas of military and civilian applications because of having many unique advantages.Data collection is the most basic applications of WSN, and it is also the basis of a variety of complex applications. Due to the energy, computing capability and bandwidth of single node are very limited, traditional wireless routing protocols are not suitable for WSN. So the primary objective of WSN routing protocol design is efficient use of node energy and extending the lifetime of the network. In the current study, clustering Algorithms is considered one of the most effective ways to solving the problem of efficient energy management, the network scalability and extending the lifetime of the network.Firstly, this thesis introduces the concept of WSN, and then the development, research status, architecture, characteristics and application area of WSN were summarized. Following, the Evaluation Standard and classification of the routing protocols for WSN were discussed in detail. And the thesis analyzes several existing typical WSN routing protocols. Then focus on the basis of PEGASIS, the hierarchical chain-tree routing protocol was put forward and expounded. In hierarchical chain-tree, the entire network area was divided into several ring levels according to the distance of sensor nodes from the sink and signal strength contour lines. And then the sensor nodes were identified based on the hierarchy, the nodes at the same level have the same node ID. The realization of the process of this algorithm is: First of all, the main chain is established using greedy algorithm in the proximate region from sink, and then some branch links from outer level to inner was gradually established and connected to the main chain, so a forward chain-tree is constructed. Then the nodes on the chain-tree communicate to sink as the root node by turns, data was transmitted and aggregated to the sink along the chain-tree at last. Finally, the hierarchical chain-tree algorithm is simulated by NS2 Platform. The simulation results of lifetime and average Delay were obtained under the different scenes and parameters. Simulation results shows that the algorithm of hierarchical chain-tree could prolong the lifetime of WSN and balance the energy consumption of WSN about 15% than PEGASIS protocol did. The fact demonstrates that the hierarchical chain-tree algorithm to improve the performance of PEGASIS is effective. Overall,the research of hierarchical chain-tree routing protocol has a certain reference value in extending the lifetime and energy balance of WSN.