Rcscarch And Improvement Of Clustering Algorithms In Wireless Sensor Networks Based On Leach

The wireless sensor network is one kind of new network, including numerousleading technologies, for instance, the embedded technology, the distributionalprocessing technology and the wireless communication technology. The characteristicof this network is that it can collect the data message by the inexpensive sensor node inthe given region, and send the collected data to the base node by way of wirelesscommunication. Currently, the sensor node has been applied into the transportation,agricultural irrigation, and other industries. It is worthy of researching and is a hot spotin the current technical research.The sensor network is made of the integration of embedded technology node. Assome special drawbacks, such as the computing power and the node energyconsumption, make the routing technology in the traditional network and Adhotnetwork can not be used in the wireless sensor networks. Therefore, how to design awireless routing protocol that is energy saving and network life cycle lengthening is themost important thing in the sensor network research.To begin with, the paper analyzes the classic routing protocols–self-adaptiveclustering hierarchical routing protocol that is the LEACH protocol, and summarizes itsstrengths and weaknesses; then improves the deficiencies of the LEACH protocol, gainsnew cluster head selection algorithm and routing algorithm, comes up with hierarchicalclustering routing protocol LEACH-G based on group and the routing algorithm basedon A*. The characteristics of the protocol show in the following two sides:First: In the original LEACH agreement algorithm, it only gets the most superiorcluster number by taking the internal node and the top node of the clusters, and the topcluster node with the energy consumed in the base depot data transmission. However,the number of this cluster is an expected value. In the practical sensor networkenvironment, as the randomness and instability of the computational method, it willcause the instability of the most superior cluster number, which will influence theperformance of the network. Meanwhile, the LEACH protocol will select the top clusternode randomly, thus the number will deviate from the most superior cluster number.When the number of the top cluster node is too few, the network will loss the concept oflayers. The too much consumed energy of some top node of the cluster will cause thepremature death of the node; when the top node cluster is excessive, it will cause theoversized power of the base depot transmission data, which will affect the entirenetwork energy consumption, thus reducing the life cycle of the network. Whencomputing the number of the most superior cluster, the LEACH-G protocol willcompute the energy consumption in the top cluster selection, gain a new superior topcluster, then introduce the concept of group. After gain the number of the top cluster,according to some algorithms divide the number of the nodes in the network into theteam with the same number of the most superior cluster, then select one top cluster node according to the size of the dump energy. In this way, make the number of the selectedtop cluster become equal to the number of the most superior top cluster, which willavoid the insufficiency of the original LEACH protocol, save the energy consumption ofthe network, and expand the life cycle of the network.Second: after the LEACH protocol choosing the top cluster, it will enter into thestable transmission node of the data. The top cluster node here after collecting the fuseddata of the non-cluster will send the fused data to the base depot node by way of singlestep communication. The top cluster node in the sensor network is far away from thebase depot node, so the massive data transmission will consume excessive energy, thuscausing the top cluster node dead in advance. To solve this problem, the paper proposesthe LEACH-A*algorithm, which uses the distance between the top cluster nodes andthe corresponding energy conception, and also combines with the heuristic searchingalgorithm to get the multi-leap communication mode. Between the top cluster node andthe base depot node, there is a mode of multi-leap data communication, which can avoidpre-death of some top cluster node, and can spread the energy consumption of single topcluster to the whole sensor network, thus to lengthen the life cycle of the network andimprove the transmission quality.Finally, carrying on the LEACH-G and LEACH-A*simulation in NS-2, the resultshows that the improved LEACH protocol obviously precedes the original LEACHprotocol in the aspects of network life cycle, the network survival nodal points, and thenetwork energy consumption, etc.