| Wireless sensor network consists of small nodes with sensing, computation, and wireless communications capabilities. It's an integrated intelligent information system which includes information gathering, processing and transmission. In military application, environmental observation and forecasting system, health care, smart home, building condition monitoring and many other fields, wireless sensor networks have broad application prospects and it's a very active research area. Wireless sensor network is taken as one of the 21st century's top 21 influential technologies in American Business Week, and it's also taken as one of top 10 technologies of changing world in the technical report of MIT comment projections of the future development of technology.Since the sensor networks consist of a large number of sensor nodes, the cost of a single node is very important to justify the overall cost of the networks. If the cost of the network is more expensive than deploying traditional sensors, then the sensor network is not cost-justified. As a result, the cost of each sensor node has to be kept low. In addition, sensor nodes, being micro-electronic devices, can only be equipped with a limited power source. Therefore, sensor nodes' memory capacity is small and the CPU's frequency is low. As a result, sensor nodes can only store and process very limited data and therefore wireless sensor networks need to be connected with an external network. Then sensor nodes can transmit the sensing data to the server with large capacity memory on the external network, while the external network users can monitor and control wireless sensor networks. Therefore, it's a very significant issue that how to interconnect wireless sensor networks with Internet, but how to communicate effectively between wireless sensor networks and Internet is an open question. IPv6 protocol family are primary protocols for the next generation Internet, which has done a great improvement in address space, message format, security and others. Some new features in IPv6, such as huge address space, neighbor discovery, address autoconfiguration and so on, provide feasibility for some wireless sensor network applications. Sensor nodes are low power micro devices, but IPv6 doesn't take embedded applications and power consumption into consideration at first. Therefore, it's a challenge issue that how to implement IPv6 protocol stack in sensor nodes.In wireless sensor networks, each node communicates with other by using some specific application-related protocols, which can improve the efficiency of data transmission and save sensor nodes' power consumption. Then it needs some proxy servers to interconnect wireless sensor networks with external networks. However, the drawback is that the protocol stack in the proxy servers is related to applications without scalability and portability and the external network users can't directly access any sensor node. This dissertation researches how to interconnect wireless sensor networks with IPv6 network and presents solutions combining the features of wireless sensor networks and IPv6 network.The research is mainly concentrated in the following facets:(1) Research on interconnecting architecture between wireless sensor networks and IPv6 networksIt's an open question that how to interconnect wireless sensor networks with IPv6 networks. In this dissertation, several methods for interconnecting wireless sensor networks with IPv6 networks are firstly introduced and analyzed. Then, more attention is paid on discussing the significance of all-IP interconnection method and key technologies to be tackled with. A conclusion is drawn from the analysis that all-IP interconnection method is an important viewpoint to interconnect wireless sensor networks with IPv6 networks, and some work with regard to it need to be further carried out. (2) IPv6 protocols reducing algorithmIPv6 protocol family is primary protocols for the next generation Internet, and it doesn't take embedded applications and power consumption into consideration at first. Sensor nodes has limited memory capacity and computing ability. Therefore, IPv6 must be reduced to be implemented on sensor nodes. Based on the features of wireless sensor networks, this dissertation proposes an IPv6 protocol family reducing algorithm and presents a simple energy consumption model for analyzing the reducing algorithm. In addition, the reduced IPv6 protocol stack implemented on the MPR2400 Micaz nodes, and experiment result shows that it's feasible to implement IPv6 on sensor nodes.(3) IPv6 routing algorithms in wireless sensor networksIn wireless communication, energy consumption grows exponentially with the incensement of distance. Sensor nodes are usually equipped with limited energy and wireless sensor network coverage is usually very large. Since sensor nodes are densely deployed, neighbor nodes may be very close to each other. Hence, multihop communication in wireless sensor networks is expected to consume less power than single hop communication. A routing protocol will be responsible for data transmission from source node to the destination node, including optimizing path between source node and destination node and forwarding data along the optimal path correctly. Based on the features of wireless sensor networks, this dissertation presents an automatic address configuration algorithm and an IPv6 routing algorithm in wireless sensor network. In addition, the algorithms analysis and simulation experiments are given in the end.(4) The implementation of IPv6 over IEEE 802.15.4IEEE 802.15.4 is a standard for low rate wireless personal area network. The standard is a generally used in wireless communication industry for it takes full ac-count of the demand for wireless sensor network applications. In this dissertation, some features of IEEE 802.15.4 networks are firstly introduced. Then an IPv6 over IEEE 802.15.4 embedded protocol design solution is proposed and some key technologies (e.g., packet compression) are discussed. At last, IPv6 over IEEE 802.15.4 protocol stack is installed on the MPR2400 Micaz nodes.(5) Wireless sensor networks protocol testingProtocol testing is an effective activity for finding and removing implementation defects. It is the last phase before the product is shipped to customers. Wireless sensor networks consist of a large number of sensor nodes and the sensor nodes distribution spatiality is poor, such as wireless/acoustic interference, malicious destruction and so on. As a result, it's a very hard even impossible task to test protocol or other testing in a real network for wireless sensor networks. In order to enable design and development of new protocols and applications for wireless sensor networks and evaluation of their performance, it's very important to build simulation environment. Based on the features of wireless sensor networks, this dissertation presents models for sink nodes, wireless channel, sensor nodes, sensor channel, target nodes and others and develops a component-based compositional simulation environment in Java.This dissertation proposes and designs a solution to implement IPv6 in wireless sensor network. The innovation of this dissertation includes the following parts. Firstly, in order to interconnect wireless sensor networks with IPv6 networks, an IPv6 protocol reducing solution for wireless senor networks is presented and all-IP interconnecting method is realized by using reduced IPv6 protocol stack. Secondly, considering wireless sensor networks power consumption, an IPv6 over IEEE 802.15.4 solution is proposed and a packet compression algorithm is presented. Thirdly, based on the features of wireless sensor networks, an automatic address configuration algorithm and an IPv6 routing algorithm in wireless sensor networks are presented. Finally, a highly scalable simulation platform for wireless sensor networks is proposed, which provides simulation environment for design and development of new protocols and applications for wireless sensor networks and evaluation of their performance.
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