Ad Hoc Networks Based On Fuzzy Control Study Of The Clustering Strategy

Mobile Ad Hoc network is multi-hop temporary automated system which consists of a group of mobile terminal nodes. The architecture of Ad Hoc network is divided into planar structure and hierarchical structure. In the planar structure, all nodes are theoretically equal. In the hierarchical structure, Ad Hoc network is classified in clusters which consist of one head cluster and other sub-clusters. Cluster head take charge communicating with in a cluster, and with other clusters. The task for the head cluster is comparatively loaded, so it likely becomes the bottle-neck of the network. Therefore, it's essential for the normal function of network to choose the head cluster reasonably. The selection of the head cluster depends on the execution of the clustering algorithm, which performance directly affects the capability of the clustering structure.The thesis firstly explains the technology of Ad Hoc network, and introduces clustering algorithms of Ad Hoc network. Several typical clustering algorithms in Ad Hoc network are discussed, compared and analyzed. A multi-weight clustering algorithm based on a fuzzy controlling technique is proposed. The algorithm takes the aspects of node velocity, degree, average lifetime of links and remaining energy into account, and makes the clustering strategy more similar to the practical situation.Secondly, The use of fuzzy controlling techniques is investigated. For average lifetime of links and remaining energy of node, fuzzy membership functions are defined. The simulation test shows that comparing with the original algorithm, advanced algorithm can reduce the communicational times and greatly improve the performance without obviously increasing the account and communicational expenditure.At last, the thesis gives a conclusion and presents the research direction.