Research On Time Synchronization Of Wireless Sensor Networks

Recent advances in miniaturization and low-cost, low-power design have led to active research in large-scale networks of small, wireless, low-power sensors and actuators. Wireless Sensor Networks(WSNs), which are the newest technology of information collecting and processing, have a wide range of application including military and business. WSN also is the newest network, and become one of the research hot-points around the world. Comparing with the traditional wireless networks, WSN has very clear differences in the design target, technology requirement and application requirement.Time synchronization is a critical piece of infrastructure in any distributed system, but wireless sensor networks make particularly extensive use of synchronized time. Almost any form of sensor data fusion or coordinated actuation requires synchronized physical time for reasoning about events in the physical world. However, while the clock accuracy and precision requirements are often stricter in sensor networks than in traditional distributed systems, energy and channel constraints limit the resources available to meet these goals. New approaches to time synchronization can better support the broad range of application requirements seen in sensor networks, while meeting the unique resource constraints found in such systems.Based on the existing theories and productions, this dissertation is to further research on time synchronization of WSNs, analyze the need to time synchronization algorithm of WSNs, clock model, synchronization classification, and discuss several time synchronization mechanisms and make comparison. And then, according to two classical time synchronization—RBS and TPSN, we have improved them. These two algorithms are not fit for dense network. So, this dissertation gives an algorithm which is for dense network and compromises between complexity and errors. Compared with TPSN, it needs not to set up the level hierarchy and then synchronize so that it can reduce the operations and complexity. Compared with RBS, it can cut...