On-demand Timing-Sync Protocol With Routing Service For WSN

Time synchronization technology has become an important supporting technology in the wireless sensor network, the characteristics of wireless sensor networks determine the importance. As we all know, time synchronization in distributed systems is a technique with very high utilization, which involves the distributed task collaboration of each node in the system, the internal clock skew of each node makes this collaboration is almost impossible. Since each sensor node's energy is limited, the data transmit rate is not high, so NTP and GPS and other the complex technical in large energy loss have been widely in the internet can not be used in wireless sensor networks, a time synchronization protocol with simple convenient, low energy consumption must be designed. Based on the above considerations, there are many wireless sensor network time synchronization protocols available, such as RBS, TPSN, LTS, TS/MS, DMTS and so on.This article proposed an On-demand Timing-sync Protocol with Routing Service OTPRS integrated with network layer routing protocols, which based on TPSN (Timing-sync Protocol for Sensor Networks) and RBS(Reference-Broadcast Synchronization) time synchronization protocols has been widely recognized in wireless sensor networks.OTPRS taken time stamp and compensation in the MAC layer, the design not only improves the accuracy and reduce errors and compared to TPSN and RBS, on-demand synchronization idea abolished the energy and time consumed in the stage of level discovery, and reduced the unnecessary full network time synchronization in some applications, the nodes synchronization in the single-hop for error control on achieved good results, and due to a combination of the advantages of routing protocol in multi-hop time synchronization, neighboring nodes paired two-way time synchronization in the stage of the route request and route reply, greatly reducing synchronous packet transmission, and this limited the data rate wireless sensor networks, no doubt, is a major step forward. The simulation experimental results show that compared to TPSN and RBS time synchronization protocol, the packet switching overhead and energy consumption, and the range of error are controlled in terms of a certain level, and achieved significant results.Finally, the article summarized, gives the future direction of further study.