Research Of Key Issues In Wireless Sensor Network Appications

Wireless Sensor Network (WSN)is a new style network integrated with many modern technology, including sensor technology, micro-electrony and mechanism system technology, wireless communication technology and information processing technology. Wireless Sensor Network has been a hot issue and has received considerable attention for decade As we all known, most sensor network is deployed in a random mode. Nodes do not have any information about neighbors and topology of the network at the start. The computing resources of microsensor nodes are highly limited, which influences the design of WSN security techniques. Wireless sensor networks are being deployed for some practical applications, including military sensing and tracking, environment and security monitoring, equipment and human monitoring and tracking, and efficient applications of them has received considerable attention. It is an important challenge to find out suitable security protocol and technology for wireless sensor networks due to limitations of power, computation capability and storage resources. In all application concerns of wireless sensor networks, localization scheme, nodes connectivity and efficient routing mechanism are most important.The structure of the dissertation is arranged as followings: the first chapter introduces current researching status of wireless sensor networks. The second chapter gives the introduction of wireless sensor networks research fields. The third chapter gives proposed a novel identity-based authentication localization scheme for wireless sensor networks. The fourth chapter states a scheme to make those unreachable nodes be able to communicate with base station. At the same time, a judgment algorithm for nodes connectivity based on a normal wireless sensor network model was proposed. The fifth chapter shows an adaptive routing mechanism for wireless sensor networks, this mechanism can adopt different routing schemes according to the remaining energy and desinity of the nodes in the network The sixth chapter mainly introduces several future research objects for our project.Considering severe resources constraints and vulnerable of wireless sensor networks, some efficient resourse-costly techniques can not be applied in wireless sensor networks. The thesis proposed a novel identity-based authentication localization scheme for wireless sensor networks. The proposed authentication localization scheme can be applied in the three components of localization system and make them safe through verification. Comparing the proposed authentication localization scheme with other secure localization technologies through comprehensive analysis in terms of the energy usage, storage cost and security in the presence of all kinds of attacks, the results show that the proposed authentication localization scheme is the most efficient for wireless sensor networks.It was crucial to acquire the knowledge of nodes connectivity before management, application and research of wireless sensor networks when they had been deployed in the interest randomly. Under real environment there can be some nodes called‘unreachable node’in interest, which could not communicate with base station for some reason, for example there are some nodes lie out of the radio range of base station or the interest range. The thesis proposed a scheme to make those unreachable nodes be able to communicate with base station. At the same time, a judgment algorithm for nodes connectivity based on a normal wireless sensor network model was proposed. In simulation we set two-experiment scheme to test the proposed scheme and judgment algorithm. From the results of simulation, we can conclude that the proposed scheme can improve nodes connectivity in the interest and the proposed algorithm can judge the connectivity efficiently and accurately.Because of limitations of power, computation capability, storage resources and networks bandwidth, the routing problem is a main concern in wireless sensor networks. This thesis proposes an adaptive routing mechanism for wireless sensor networks, this mechanism can adopt different routing schemes according to the remaining energy and desinity of the nodes in the network. The theory and the application analysis demonstrate that the proposed mechanism is able to expand the mean alive lifetime for wireless sensor networks; at the same time,the proposed mechanism can make the data transmission in wireless sensor networks to be more effective and more reliable.