Accurate MAC clock synchronization technique for real-time service in ad hoc network

Supporting real-time service in ad hoc network has emerged as an interesting and important research area in recent years. Time synchronization plays a critical role in such kind of MAC protocols. In this paper, we introduce an accurate clock synchronization technique for IEEE802.11 interface in TDMA based ad hoc network. The advantage of Reference Broadcast Synchronization (RBS) is explored to find out the fast clock in the network. Further more an advanced clock adjustment scheme is proposed to ensure the accuracy of node clock. Analytical performance results are presented showing the advantage of the proposed technique as an accurate synchronization approach. We applied the proposed scheme to support a TDMA based real-time service MAC protocol and run the simulation under the random waypoint (RWP) model. Performance results show that the logical clocks converge after 35 seconds, approximately four times of that of the fixed scenario. And the maximum clock offset is bound in the order of 10 μs after convergence.