Research Of Load-balancing Based Routing Protocols In Wireless Sensor Networks

Wireless sensor networks(WSN) are multi-hop self-organized network systems in which massive sensor nodes are randomly deployed to communicate with each other. The performance of routing protocol which is regarded as one of the crucial techniques in WSN will straight affect the efficiency of the entire network. In recent years, it has made a quite great progress but still has not formed a uniform standard in research of WSN's routing protocol. Each sensor node has limit energy. Some nodes and even the entire network may soon decease due to the unbalanced consumptions of sensor nodes'energy which result from funneling effect, routing holes or many other reasons. Thus it can be seen that constructing load-balancing based routing protocols to prolong network lifetime is a very essential and challenging research issue in WSN, and is of great significance as well.In this paper, we study the load-balancing based routing technology of wireless sensor networks completely and in depth. At first, we introduce the basic concepts, key techniques and underlying challenges of WSN. Then, we investigate the characteristic and the design objective of WSN's routing protocols. We classify the existing typical routing protocols and represent the related work of the load-balancing based routing protocols of WSN.This paper mainly focuses on the research of the load-balancing based routing protocols of WSN. Aiming at hierarchical routing structure and flat routing structure, we propose two load-balancing based routing protocols respectively. The main achievements of this paper are listed as follows:(1) In wireless sensor networks, monitoring data possesses fairly good similarity of nodes' readings. According to this applying background, we propose a Local Energy- Efficient and Aggregation Clustering Protocol (LEEAC) which is based on data aggregation in this paper. Through the data dissimilarity degree which reflects local space similarity, the LEEAC restricts the residual energy of nodes and employs the predict energy restricted as the main criterion for electing cluster heads. The cluster heads which have been elected distribute well in sensor networks. Besides, by bringing in data critical code, the LEEAC reduces the communication content during data transformation within the cluster and the load on data aggregation of the cluster head. In this way, the energy consumption has been greatly saved. The result of our simulation proves that the LEEAC can effectively balance energy consumption and prolong the network lifetime.(2) In this paper, we propose a Load-balancing Based Optimal Routing Protocol (LORP) to address the routing problem in the bottlenecked networks which contain"routing holes". By finding the boundaries of holes and sensor field in the bottlenecked network using an existing algorithm, LORP identifies the bridges in the sensor field using our MACB algorithm. A centralized optimal solution for the balance-first bridge assignment is presented using a binary integer programming model. Our simulation shows that LORP achieves good load balancing, prolongs the network lifetime, and significantly improves the quality of network service.We have made some achievements on study of the load-balancing based routing protocols of WSN, but it still remains a lot of awkward problems which need to be studied more in depth in future work.