Abstract: A multichannel slot structure based on Time Division Multiple Access (TDMA) in Ad Hoc network was designed. According to the basic principle of Network Time Protocol （NTP）and the new slot structure, an algorithm for slot synchronization of the whole network was proposed. The proposed algorithm inherited slot synchronization of point to multi-point wireless communication system. The initial slot time synchronization of the whole network was completed after the time adjusting of master-slave synchronization, then the step of slot interactive synchronization started. In this step, the periods of slot interactive synchronization must be set so properly according to the guard interval length, the clock differences and the moving speed of network nodes that not only the network load was not increased, but also the slot collision was avoided. Simulation results show that the proposed algorithm has minimal time deviation and can realize synchronization rapidly. The method can be applied to Ad Hoc network based on TDMA.

Key words: Network Time Protocol (NTP), multi-channel slot, Ad Hoc, slot synchronization

摘要： 基于无线Ad Hoc网络时分多址接入机制，设计一种多信道时隙结构。根据网络时间协议(NTP)的基本原理，提出基于该时隙结构的全网时隙同步算法。该算法继承了点对多点无线通信系统的时隙同步方式，在完成时隙主从同步调整后，实现全网时隙的初始对齐，然后进入时隙互同步调整阶段，根据网络节点时钟偏差、节点移动速度和保护时隙的长度，设置合理的互同步调整周期，既不增加网络流量负荷，又可保证各节点发射时隙不碰撞。仿真结果表明，该算法具有较小的时间同步偏差，能快速实现全网的时隙同步，可应用于基于TDMA方式的Ad Hoc网络。

关键词: 网络时间协议, 多信道时隙, Ad Hoc, 时隙同步