Time Synchronization for Failure Tolerance in Wireless Sensor Network

Node in WSN has its own local clock, and it´s difficult to achieve long-term time synchronization between nodes due to some internal and external factors. Within the factors, some internal attackers (group members) report false clock references to their neighbor nodes. Considering the special circumstance that some nodes of the wireless sensor network are faulty, an improved HRTS algorithm named T-HRTS which based on Hierarchy Referencing Time Synchronization resolving the byzantine general problem will be introduced. In T-HRTS, It is the node possessing major clock, but not the root node of each level which is regarded as the reference node. If the root is fault, the normal clock will be the major clock instead of the root´s clock. Therefore, common clock throughout the network will be adjusted according to major clock and the nodes with major clock need not adjust its own clock. Thereby, it can tolerant fault and reduce the clock adjusting time.