Research And Design Of A Time Synchronization Algorithm With Monitoring Mechanism

In recent years,with the rapid development of wireless sensor network,its related technologies have been further studied.As one of the important technologies of WSN,time synchronization technology is the premise of maintaining the time consistency of WSN component nodes and ensuring that nodes work together.It plays a vital role in related technologies such as information collection,sniper location and data fusion.Therefore,the study of time synchronization technology has important theoretical significance and valuable engineering realization value.However,reliable synchronization accuracy typically requires a large amount of information interaction,resulting in a large amount of synchronization overhead.Aiming at the mutual constraint relationship between synchronization precision and synchronization overhead,this paper completes the design of related algorithms based on the typical Timing-sync Protocol for Sensor Network,and completes the experiment verification and analysis based on CC2530 hardware platform.In order to ensure the synchronization accuracy,this paper selects TPSN as the basic algorithm and designs an improved TPSN algorithm(S-TPSN)based on the Start of Frame Delimiter(SFD).The S-TPSN algorithm uses the SFD interrupt capture timestamp to eliminate partial delays,and uses the least squares method to estimate and compensate for clock skew while preserving the TPSN algorithm to compensate for the clock offset immediately.The experimental results under star,chain and tree structure show that the S-TPSN algorithm controls the star-shaped single-jump error at 0.968?s,the 4-hop chain error to 4.576?s.The 4-hop tree error is controlled to about 3?s(maximum value is 3.061?s,minimum value is 2.868?s).The S-TPSN algorithm controls the synchronization accuracy to a subtle level,ensuring synchronization accuracy.On the basis of ensuring the synchronization accuracy,this paper introduces a broadcast mechanism based on the S-TPSN,and combines the receiver-receiver and sender-receiver synchronization modes to design a time synchronization algorithm with listening mechanism(OS-TPSN).While retaining the S-TPSN algorithm hardware capture timestamp and synchronization error compensation mode,the OS-TPSN algorithm realizes network synchronization by means of nodes in the communication range listening to two-way synchronization packets.The experimental results under star and tree structures show that the OS-TPSN algorithm controls the single-hop synchronization error at 2.047?s.In the multi-hop error,the synchronization accuracy of the two monitoring nodes in the 4-hop listening error is 8.193?s and 5.241?s,respectively.Compared to the single-hop synchronization accuracy of 0.968?s in the S-TPSN algorithm,although the OS-TPSN algorithm loses a certain synchronization precision,it uses the node monitoring method to achieve synchronization,which reduces a large amount of information interaction,so that the synchronization overhead is significantly reduced,and the relative balance between accuracy and energy consumption is achieved.