LIU Di-xin

(School of Instrumentation Science & Opto-electronics Engineering, Beihang University, Beijing 100191, China)

Abstract: On the basis of analyzing and summarizing the features and problems of the existing time-synchronization algorithms, an improved model for TPSN(time-sync protocol for sensor networks), which takes into account both the offset and the frequency drift rate of the clocks of sensor nodes, is proposed. The clock offset and frequency drift rate for sensor nodes are estimated and then compensated by using the time-stamp recorded in two adjacent synchronizations. Compared with the traditional one, this new model can achieve lower cost and higher precision for a long time. Finally, the mathematical analysis and simulations are presented for verifying the effectiveness of this new model.

Key words: time synchronization; wireless sensor networks; clock drift rate