A Study On The Application Of Broadcasting Distribution In The Ad Hoc Networks

Mobile Ad Hoc Networks (MANET) is an important communication network, with an open radio channel, dynamic topology, without centralized infrastructure, etc. Because of these features above, make the MANET more suitable to be used in meetings, academic exchanges, field communications, and other aspects of the rescue, compared to traditional wired networks. However, there are still some open issues in MANET, such as the network broadcast, dynamic network management and resource discovery, etc. Thus this paper gives some solutions which are aimed at solving broadcasting distribution and dynamic network management problems.First, this paper regarding to the problem of slow progress and high overhead, when constructing a tree-like CDS in a fast-moving ad hoc networks, puts forward a Zone-based distributed heuristic approximation algorithm for minimum connected dominating set(ZBCDS), on the basis of the ideas of the "field". ZBCDS defines the concept of potential-rank and candidate nodes, on the basis of calculating maximal independent set, optimizes the zone partition and the adjustment along the zone borders via nodes judging their own potential-rank, finally reaches the aim of rapidly and efficiently reconstructing CDS as topology change. Experimental results show that ZBCDS can rapidly and efficiently construct CDS, with a smaller size of CDS and less time complexity.Second, for ZBCDS is lack of the necessary features for measuring the mobile node, resulting in links broken down from time to time, instability virtual backbone. The algorithm draw the idea of the relative mobility into ZBCDS, then proposes a relative mobility based distributed heuristic approximation algorithm for minimum connected dominating set(MB-ZCDS). The algorithm based on relative mobility, makes the node in the same zone with similar mobile characteristics, thus ensuring the stability of the link.Finally, this paper designs a file broadcasting distribution protocol, based on the MB-ZCDS. The protocol uses MB-ZCDS algorithm to construct a virtual backbone network. This paper also designs a dynamic mobility management mechanism according to the MB-ZCDS algorithm for the need of the maintenance of the virtual backbone. And using NS-2 network simulation platform to study the protocol performance with different speed and different number of nodes. Simulation results show that the proposed file broadcasting distribution protocol can achieve good performance.The conclusion drew by this paper is useful for the research and realization of the file broadcasting distribution in the MANET, which have a value of the practical application of the theoretical reference value.