Phan Linh-An, Kim Taejoon, Kim Taehong, Lee JaeSeang, Ham Jae-Hyun
School of Information and Communication Engineering, Chungbuk National University, Cheongju 28644, Korea.
The 2nd R&D Institute-Agency for Defense Development, Daejeon 34186, Korea.
Sensors (Basel). 2019 Jul 9;19(13):3020. doi: 10.3390/s19133020.
The time synchronization protocol is indispensable in various applications of wireless sensor networks, such as scheduling, monitoring, and tracking. Numerous protocols and algorithms have been proposed in recent decades, and many of them provide micro-scale resolutions. However, designing and implementing a time synchronization protocol in a practical wireless network is very challenging compared to implementation in a wired network; this is because its performance can be deteriorated significantly by many factors, including hardware quality, message delay jitter, ambient environment, and network topology. In this study, we measure the performance of the Flooding Time Synchronization Protocol (FTSP) and Gradient Time Synchronization Protocol (GTSP) in terms of practical network conditions, such as message delay jitter, synchronization period, network topology, and packet loss. This study provides insights into the operation and optimization of time synchronization protocols. In addition, the performance evaluation identifies that FTSP is highly affected by message delay jitter due to error accumulation over multi-hops. We demonstrate that the proposed extended version of the FTSP (E-FTSP) alleviates the effect of message delay jitter and enhances the overall performance of FTSP in terms of error, time, and other factors.
时间同步协议在无线传感器网络的各种应用中不可或缺，例如调度、监测和跟踪。近几十年来，人们提出了众多协议和算法，其中许多都提供了微尺度分辨率。然而，与在有线网络中实现相比，在实际无线网络中设计和实现时间同步协议极具挑战性；这是因为其性能会因诸多因素而显著恶化，包括硬件质量、消息延迟抖动、环境以及网络拓扑。在本研究中，我们根据实际网络条件，如消息延迟抖动、同步周期、网络拓扑和丢包情况，来测量泛洪时间同步协议（FTSP）和梯度时间同步协议（GTSP）的性能。本研究为时间同步协议的运行和优化提供了见解。此外，性能评估表明，由于多跳上的误差累积，FTSP受消息延迟抖动的影响很大。我们证明，所提出的FTSP扩展版本（E-FTSP）减轻了消息延迟抖动的影响，并在误差、时间和其他因素方面提高了FTSP的整体性能。
