Researches On Clustering Algorithms In Wireless Sensor Networks

Routing technology at the network layer is pivotal in the architecture of wireless sensor networks. As an active branch of routing technology, cluster-based routing protocols exceles in network topology management, energy minimization, data aggregation and so on, it has become one of the most hotspots of researches on WSN(wireless sensor networks). In this paper, cluster-based routing mechanisms for WSN are analyzed. Cluster head selection, cluster formation and data transmission are three key techniques in cluster-based routing protocols.Researches in this thesis include:1. One of the significant challenges is how to subdivide the sensor network into reasonable and stable network structure? To address the above problem, in this thesis, a literature review on the wireless sensor network clustering algorithms is provided. Many clustering algorithms that have been presented, such as LEACH which decides the clusters according to the probability theory. HEED which introduces the energy restriction shows more efficiency than LEACH.2. In this paper, we propose an optimization algorithm to avoid the shortcoming of the above-mentioned clustering algorithms by clustering using the energy information. The new algorithm defines the topology according to the energy disribution which different to the classic algorithms. And the normal nodes choose the optimized the cluster heads according to the optimizing expressions which shows the advantages than other algorithms.3. A correlation-based Clustering algorithm is proposed for the high-density WSN, which makes the nodes having the highest correlation as one virtual cluster head. The members of the cluster head work in TDMA sequences. It reduces the cluster head competiton and stable the structure of the network as long as possible.As the simulation results show that the proposed algorithms have better performances than the LEACH and HEED in certain scenes: energy balance, energy consuption, cluster stability, the prolonged lifetime. Especially the correlation-based clustering algorithm for the high density sensor networks, it has drastical advantages than LEACH when the number of nodes increases.