The Improvement And Research Of Routing Protocol In Wireless Sensor Networks

Wireless sensor network is a brand new network,which has drawn worldwide attention in recent years.It has brought profound influence to modern technology,and changed the interaction way between man and nature,WSN becomes an increasingly hot research field. WSN is a multi-hop network of self-organization system which is composed by a large number of low-cost micro-sensor nodes deployed in the monitored region.It was used to collaborate perception,collection and processing the information of object in the region covered by the network,then send the information to observers.WSN is far different from general wireless network in terms of the characteristics of network,communication mode and needs of data transmission, reflected in the specific:the constrained energy of wireless terminals,the data-centric means of communication,similarity of neighboring nodes data,specific application and topology frequent changes.According to these characteristics,it is necessary to design a reasonable routing protocol based on specific application in order to enhance the energy-saving,robustness,scalability, security of the WSN.There are several key technologies in WSN,such as routing,topology control,data aggregation,node localization,energy management etc,among which the design of routing protocols is a kernel support technique. Especially,the cluster-based routing protocol,which integrates the topology control and routing technique,has become one of the hottest research fields presently.The low-delay and the long lifetime are strongly required in commom application of real-time target monitoring in WSN.The cluster-based routing protocol has the property of low delay,but nodes wich limited energy are unable to get energy renew,so it of vital importance to design a routing protocol,which must prolong the network lifetime and improve the energy efficiency in WSN.The key point of cluster-head routing is the strategy of cluster-head selection.A node is selected to be a cluster-head based on the strategy of random selection according to its residual energy and neighbor’information, but it leads to imbalanced energy dissipation,which causes the cluster-head to die early.This is a dominant factor to decrease the network lifetime.Energy consumption is the primary concern factor due to the characteristics of WSN,for its energy and capacity are limiting.At the same time, it is hard to change them.Routing technology is one of the key technologies of WSN(Wirless Sensor Networks).Wireless sensor networks is a power-constrained network. We should reduce the energy consumption and prolonging network’s lifecycle.It is the important aim of our study. To solve this problem, based on LEACH and PEGASIS protocols, two improved algorithms LEACH-energy and APLe (Adaptive PEGASIS&LEACH-energy) were proposed in this paper. LEACH-energy is basing on the study of the typical hierarchical routing protocol LEACH. We analyzed the defect and improved two points which are the selection of cluster head and the communication of cluster head to sink point.APLe can dynamically adopt a chain or a start structure within the cluster,it not only embodies the PEGASIS and LEACH-energy in the energy-saving advantages,but also adopts cluster structure, which makes up the large delay of PEGASIS.Theoretical analysis and simulation illustrated that these two algorithms can improve the energy consumption, prolong the life time of networks and reduce the delay better than the original.