An algorithm for clock synchronization with the gradient property in sensor networks
We introduce a distributed algorithm for clock synchronization in sensor networks. Our algorithm assumes that nodes in the network only know their immediate neighborhoods and an upper bound on the networks diameter. Clock-synchronization messages are only sent as part of the communicationassumed to be reasonably frequentthat already takes place among nodes. The algorithm has the gradient property of [R. Fan, N. Lynch, Gradient clock synchronization, Distributed Computing 18 (2006) 255266], achieving an O(1) O ( 1 ) worst-case skew between the logical clocks of neighbors. The algorithms actions are such that no constant lower bound exists on the rate at which logical clocks progress in time, and for this reason the lower bound of [R. Fan, N. Lynch, Gradient clock synchronization, Distributed Computing 18 (2006) 255266; L. Meier, L. Thiele, Brief announcement: Gradient clock synchronization in sensor networks, in: Proceedings of the Twenty-Fourth Annual ACM Symposium on Principles of Distributed Computing, 2005, p. 238] that forbids a constant clock skew between neighbors does not apply.
clock synchronization sensor networks distributed computing gradient property in clock synchronization