The Design And Implement Of Broadcasting And Data Gathering Algorithms In Wireless Sensor Network

Many sensors'applications need to use the broadcasting and data gathering. Broadcasting is to dispense the information from some node to other nodes in the networks. Data gathering is to collect all other nodes'information to some central node. Sensor node's computing ability, storage capability and energy is limited. which makes it impossible to apply traditional wireless technology in wireless sensor network directly. So it is crucial to design simple and effect broadcasting and data gathering algorithms.At first, some basic concept, principle and development of wireless sensor network are reviewed in this thesis. Afterwards, the relevant research results and the problems of broadcasting and data gathering in wireless sensor network are studied deeply. On the basis of studying ant colony algorithm and existing broadcasting and data gathering algorithms, the broadcasting algorithms based on ant colony system are presented in order to solve some problems of existing broadcasting algorithm, such as restrictive condition is single, energy's restriction is not been considered or some simple heuristic algorithms are used. The broadcasting algorithms based on ant group system make use of the comparability of the broadcasting in wireless sensor network and TSP, describe wireless sensor network model as a map with power, and adopt ant system's capacity and plus feedback mechanism, and according to the given restrictive condition, to find out the credible broadcasting path, which satisfy the minimal energy. Simulation is operated with OMNET++. And the simulation results show that, the presented algorithm is simpler and more practical in energy validity, lifecycle of network and delay than traditional algorithm.Because of the advantages of ant system in resolving combination and optimizing problems, a data gathering algorithm based on ant algorithm is proposed. Fusion cost-an important characteristic of data gathering is often been neglected in some applications of wireless sensor network. It is the same with transmission cost to route. Different from existing schemes, the algorithm not only optimizes over the data transmission cost, but also incorporates the cost for data fusion. It makes use of ant group system's plus feedback character, achieves correlative data's gathering in the condition of minimizing total energy. Through extensive simulation results, it is shown that this algorithm has excellent performance behavior and provides a near-optimal solution when the connectedness of network, the number of sink, correlative coefficient and fusion cost are different, which is significant for emerging sensor network with vectorial data and/or security requirements.