Abstract: The MAC protocol based on reservation and dynamic-slot distribution can offer fine QoS guarantee for real-time traffic. One of its key technologies is how to realize the synchronism among the nodes. Therefore, a new time synchronization protocol for Ad Hoc network by means of delay-probing was put forward, which combined the merits of DMTS protocol and TPSN protocol. Through transmitting and relaying a little probing code, the protocol could complete the retardation measuring. Owing to the separation between delay-probing course and time-correcting course, the conflict and burden of the network could be lightened. Analysis and simulation indicate that DMC-TS protocol is simple to realize, and possesses a precision which can be compared with TPSN protocol.

Key words: delay measuring, probing, network layering, time synchronization

摘要： 基于预约和动态时隙分配的MAC协议能够为实时业务传输提供良好的QoS保证，其关键技术之一是如何实现节点间的同步。通过分析影响时间同步性能的6类时延，构造了一种基于时延探测方式的Ad Hoc网络时间同步协议(DMC-TS协议)，协议通过发送和转发少量的探测码来完成节点间时延的测定。由于协议中时延探测过程和时间校正过程相互分离，可以减轻网络的冲突和负担，有利于降低时延探测的时效性要求。分析及仿真表明，DMC-TS协议实现简单，精度能够和TPSN协议相比拟。

关键词: 时延测量, 探测, 网络分层, 时间同步