Maximum Probable Clock Offset Estimation (MPCOE) to Reduce Time Synchronization Problems in Wireless Sensor Networks

• DOI: 10.1007/s11277-020-07414-y
• Publication Date: 2020-05-02T11:03:31Z
• Authors: Divya Upadhyay; Ashwani Kumar Dubey
• Keywords: UTC offset; sync; Clock drift; Self-clocking signal

Time synchronization is an essential characteristic for the faithful functioning of wireless sensor networks. Hypothetically, it is stated that the two clocks are considered to be synchronized with each other if their clock offset and frequency components within the oscillator are running at the same rate. But, practically, there is some degree of inaccuracy in the manufacturing of these clocks; as a result, their frequency sources have slight variations. This paper proposes a unique mathematical model which is based on maximum probable theory maximum probable clock offset estimation, along with the propagation delay factor for finding the best probable estimate for clock offset. In addition, a novel two-way message passing scheme-based network communication model is presented here. Based on results, it has been predicted that estimating the clock offset will help in improving the efficiency of the existing time-synchronization protocols i.e. time-sync protocol for sensor networks (TPSNs). It was observed that the standard error deviation of modified TPSN with MPCEO was reduced from 2.324 to 0.064 ms. This will make the modified TPSN model more accurate, efficient, and reliable.