Enhanced Precision Time Synchronization for Wireless Sensor Networks

Sensors

Hyuntae Cho¹  Jongdeok Kim² 

[1] Institute of Logistics Information Technology, Pusan National University, Geumjeong-gu, Busan 609-735, Korea; E-Mail:;Department of Computer Engineering, Pusan National University, Geumjeong-gu, Busan 609-735, Korea; E-Mail:

关键词: time synchronization;    wireless sensor network;    lightweight;    hardware assisted time stamp;    drift correction;   

DOI  :  10.3390/s110807625

来源: mdpi

【 摘 要 】

Time synchronization in wireless sensor networks (WSNs) is a fundamental issue for the coordination of distributed entities and events. Nondeterministic latency, which may decrease the accuracy and precision of time synchronization can occur at any point in the network layers. Specially, random back-off by channel contention leads to a large uncertainty. In order to reduce the large nondeterministic uncertainty from channel contention, we propose an enhanced precision time synchronization protocol in this paper. The proposed method reduces the traffic needed for the synchronization procedure by selectively forwarding the packet. Furthermore, the time difference between sensor nodes increases as time advances because of the use of a clock source with a cheap crystal oscillator. In addition, we provide a means to maintain accurate time by adopting hardware-assisted time stamp and drift correction. Experiments are conducted to evaluate the performance of the proposed method, for which sensor nodes are designed and implemented. According to the evaluation results, the performance of the proposed method is better than that of a traditional time synchronization protocol.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.