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Authors: | Philipp Blum, Lothar Thiele |
Group: | Computer Engineering |
Type: | Techreport |
Title: | Precise and Low-Jitter Wireless Time Synchronization |
Year: | 2003 |
Month: | December |
Pub-Key: | BT03 |
Keywords: | ESD DSE SN |
Rep Nbr: | 187 |
Abstract: | In this paper, we are describing methods to perform time synchronization in a network of nodes that use wireless and ad-hoc communication, are decentralized, and have limited computing capabilities. Several new results are described. Algorithms: A new synchronization Algorithm (LSA -- Local Selection Algorithms) is presented that achieves low-microsecond precision and jitter, that is robust under instable connectivity and variable load conditions, and that requires only uni-directional communication. A variant of the algorithm (LSDC) is presented that dynamically compensates clock drift. Formal Validation: The achievable jitter and precision depend on the synchronization-message arrival-pattern and the synchronization-message delays. We propose a new analysis of clock synchronization algorithms under unknown pattern and delays, based on safety and liveness properties. LSA and LSDC are safe and live. Experimental Validation: Simulation results show that LSDC achieves 10microseconds precision on 802.11b wireless LAN in ad-hoc mode under variable load conditions. |
Resources: | [BibTeX] [Paper as PDF] |