Patent ID: 7114091
Filing Date: 2006-09-26
Classification: G06F,H04J

Abstract:
1. A system, comprising: a communication medium; a master node configured to send a plurality of sets of synchronization messages on the communication medium, and wherein each set of synchronization messages includes a plurality of synchronization messages; a slave node configured to receive each set of synchronization messages and to select a synchronization message having an optimal delay from each set of synchronization messages; wherein the slave node is configured to calculate a correction for a slave clock included in the slave node in response to timing information associated with the synchronization message having the optimal delay in each set, wherein the slave node is configured to not calculate a correction for the slave clock in response to timing information associated with at least some of the synchronization messages in each set, and wherein the slave node is configured to calculate the correction to apply to the slave clock by inputting a difference between a master timestamp difference and a slave timestamp difference into a control loop; wherein the master timestamp difference is a difference between a timestamp included in the synchronization message having the optimal delay selected from a most recently received set and a timestamp included in the synchronization message having the optimal delay selected from a next most recently received set; and wherein the slave timestamp difference is a difference between a timestamp generated by the slave node in response to receiving the synchronization message having the optimal delay selected from the most recently received set and a timestamp generated by the slave node in response to receiving the synchronization message having the optimal delay selected from the next most recently received set.