Research On Considering Performance And Energy Consumption Of DV-Hop Localization Algorithm And The Method Of Data Diffusion

The nodes localization and data transmission are two key technologies and hot topics in wireless sensor networks (WSN). Due to the limitation of nodes energy and the difficulty of the energy supply, it is of great value to research new approaches to consider the performance and energy consumption DV-Hop localization algorithm and data transmission method.Large amount of energy consumption occurs resulting from the twice flooding broadcast in the traditional DV-Hop algorithm. Besides, the unknown nodes take the average one-hop distance estimated by the nearest anchors from the nodes as themselves, which leads to the lower localization accuracy of the algorithm. In order to improve DV-Hop algorithm effectively, those positioned nodes are upgraded to be new-born anchors to favor the initial anchors and the new-born anchors are assigned corresponding generations based on the idea of incremental localization. This paper improves the estimation accuracy of the average one-hop distance by weighting the hops between the unknown nodes and anchors and the generation values of the nodes. Thus, the nodes localization accuracy could be improved effectively.It is necessary to reduce the energy consumption of the nodes and improve energy efficiency of the algorithm during nodes localization. In the thesis, the proper constraint of information transmission range is set to avoid the flooding broadcast. Meanwhile, if the unknown nodes receive the tern of anchors including two initial anchors and one new-born anchor, the nodes could locate themselves by the optimal combination of anchors unless the combination is a non-collinear tern. It is a valuable method to keep the unknown nodes from energy consumption resulting from waiting more anchors’information. In order to further improve energy efficiency of localization algorithm, the scheme of nodes power control is presented in the DV-Hop algorithm, in which the unknown node could receive the information from anchors with different power-level broadcasting earlier and locate it by itself. Simulation and analysis results show that the new algorithm can effectively decrease the positioning error and total localization rounds by comparing with the others algorithm.There are different degree decrease of nodes’ energy after nodes self-positioning, while the energy of each node is limited, which in turn determines the chosen data transmission protocol could effectively utilized nodes energy. The paper improves the performance of directed diffusion data transmission protocol by setting the fuzzy gradient model and the quality evaluation function of choosing nodes. The evaluation function contains the three factors as follows:the nodes surplus energy, the value of generation and the number of neighbor nodes. The new improved algorithm ensures the data transmit to the goal node with lower energy consumption and high reliability thus saves energy and prolongs the networks life.