The Research Of Node Deployment Scheme To Achieve Coverage And Connectivity In Wireless Sensor Network

With the development of micro-electronics technology, computing technology and wireless communications technology, wireless sensor network was concerned more and more widely, from the military field, its application has been extended to many other areas. One of the key issues in wireless sensor networks research is network coverage and connectivity. In this paper, we improve the existing grid-based coverage and connectivity issues and propose a new node deployment strategy based on the hexagonal grid configuration, furthermore we compare and analyze it with the current strategy in the research process of node random coverage and connectivity coverage issues, finally we build a hardware platform, through the experiment to verify the superiority of our proposed strategy.This paper starts with the network coverage problems. Two kinds of nodes deployment strategy based on the hexagonal grid configuration have been proposed to meet the network coverage when the sensor nodes location information can not be accessed. Meanwhile, we compare it with the existing strategy while nodes are in different discrete degree of their cases, through software simulation we demonstrate that in the issue of node random coverage the node deployment strategy depend on the dispersion of nodes. Furthermore, the simulation results show that the deployment strategy we have proposed would use fewer active nodes to meet the same region coverage.Coverage is focused on the perception of network nodes monitoring capacity, while connectivity emphasizes on the ability of how to establish communication between the network nodes and to transmit data. Therefore, the node connectivity problem has been taken into account with the issue of coverage at the same time, we propose the strategy which based on the hexagonal grid in the conditions that the radius ratio of connectivity and communication is different. Through software simulation, we find that when both connectivity and coverage problems are taken into account, the strategy based on the hexagonal grid we propose is superior to the existing strategy based on the square grid, furthermore the network can survive longer. In order to link theory and practice, we build the wireless sensor network platform, we take advantage of the TI's CC2430 ZigBee Development Kit, we design both of the wireless sensor node module and real-time data monitoring module and simulate the node deployment strategy that proposed in the paper, through the experimental results we find that in the same condintion of connectivity and coverage the node deployment strategy we proposed is better than the existing one.Finally, this paper also discusses the foreground of the reasearch, if more quality of service factors can be brought in on the theory of this paper, and node positioning system can be built on the platform, it would provide a massive boost to the practical applications of wireless sensor network.