Research On Techniques Of Data Transmission And Its Security In Wireless Sensor Networks

Wireless sensor networks have drawn much attention due to their wide applications in military and civilian operations. Detecting physical world directly, sensor networks will change the interaction between men and nature so that the logic information can be linked closely with the real physical world. However, sensor network data transmission and its security face great challenges due to the resource constrains on sensor nodes and the node compromise attacks. This dissertation makes a deep research on data transmission and its security techniques from deploying nodes to providing network services, which includes: sensor network topology control, data collaborative transmission and compression mode, broadcast authentication protocol, time-sync data filter algorithm, access control techniques, Internet connected methods and service providing methods. The main results are as following:1. Methods for sensor network topology control are studied to solve the problem of the uneven distribution of the sensor nodes. First, grid-based node deployment and node power control are investigated so that nodes are deployed evenly, and the network connectivity and the energy consumption are balanced. Based on this, LEACH is improved and GCVD topology control scheme is proposed.2. The collaborative data transmission mode is studied, by which the energy consumption in networks is reduced and the energy consumption on nodes is balanced. By a lot of redundant data in clusters and the data broadcast feature of wireless transmission, a collaborative broadcasting data compression strategy is proposed based on residual energy.3. Sensor network broadcast authentication protocols are studied, and MMμTESLA is proposed, a broadcast authentication protocol for multi-base station sensor networks, which is more applicable to a particular operation. To resist the attacks from DoS, DoM, authentication deday and false messages, MMμTESLA is extended to RDS-μTESLA, RDM-μTESLA, RAD-μTESLA and RFM-μTESLA. MMμTESLA requires high time synchronization asμTESLA, so FSTP is analysed and a linear regression time-sync data filter algorithm for sensor networks is designed.4. The access control schemes for sensor network services are developed to a one way hash chain based access control scheme. Then Merkle hash tree is introduced to extend the capabilities of this access control scheme so that the node storage costs are reduced. Besides, to resist the attacks from user compromised, a withdrawal method of users' access ability is presented. 5. The technique of connecting Internet into sensor networks is studied to solve the problems in providing services by sensor networks for Internet users. First, the architecture of connecting Internet into sensor networks is provided, WSN-Internet gateway is designed, and the data package conversion between sensor networks and Internet are realized. Then with the middleware, scheme of providing network services is suggested.