Time synchronization for wireless sensor network based on major clock

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, a special one is Byzantine general problem which will be discussed in this article. Considering the special circumstance that some nodes of the wireless sensor network have the same clock, an improved HRTS algorithm which based on pair-nodes by reversing Hierarchy Referencing Time Synchronization will be introduced. It is the cluster head 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, it is the root but not the neighbor nodes possessing majority clock at the same level that need adjust the clock. Thereby, it can tolerant fault and reduce the clock adjusting times.