Time synchronization is an important issue in ad-hoc networks for reliable information exchange. The algorithms for time synchronization in ad-hoc networks are largely categorized into two types. One is based on a selection of a reference node, and the other is based on a consensus among neighbor nodes. These two types of methods are targeting static environments. However, synchronization errors among nodes increase sharply when nodes move or when incorrect synchronization information is exchanged due to the failure of some nodes. In this paper, we propose a synchronization technique for mobile ad-hoc networks, which considers both the mobility of nodes and the abnormal behaviors of malicious or failed nodes. Specifically, synchronization information extracted from a median of the time information of the neighbor nodes is quickly disseminated. This information effectively excludes the outliers, which adversely affect the synchronization of the networks. In addition, Kalman filtering is applied to reduce the synchronization error occurring in the transmission and reception of time information. The simulation results confirm that the proposed scheme has a fast synchronization convergence speed and low synchronization error compared to conventional algorithms.

中文翻译：

---

移动Ad-Hoc网络的中值卡尔曼滤波实现ast和鲁棒的时间同步

时间同步是自组织网络中可靠信息交换的重要问题。ad-hoc网络中的时间同步算法主要分为两种。一个基于参考节点的选择，另一个基于相邻节点之间的共识。这两种方法都针对静态环境。但是，当节点移动或由于某些节点的故障而交换不正确的同步信息时，节点之间的同步错误会急剧增加。在本文中，我们提出了一种用于移动自组织网络的同步技术，该技术同时考虑了节点的移动性以及恶意或故障节点的异常行为。具体地，从邻居节点的时间信息的中值提取的同步信息被迅速地传播。该信息有效地排除了异常值，这些异常值会对网络的同步产生不利影响。另外，应用卡尔曼滤波来减少在时间信息的发送和接收中出现的同步误差。仿真结果表明，与传统算法相比，该方案具有更快的同步收敛速度和较低的同步误差。