Clock Synchronization Using Correlation Events

摘要

Two clocks may be synchronized by calculating skew and offset values that may be determined from several correlation events. A correlation event may be the passing of messages in both directions between the two devices. The skew and offset values may be used to determine the time of non-correlated events. The clock synchronization may be performed on a real time basis or may be performed on a post processing basis. One method for calculating the skew and offset may use inequalities within a solution space to refine a solution set with multiple sets of correlation events.

主权项

1. At a device, a method implemented on a processor, said method comprising:
identifying one or more correlation events occurring between a first device having a first clock and a second device having a second clock; determining that a solution set for an expression of the differences between said first clock and said second clock is not bounded, the solution set defining a linear relationship between said first clock and said second clock based on said one or more correlation events; in response to determining that said solution set is not bounded:
identifying a further correlation event between said first device and said second device;calculating a linear inequality for said further correlation event; andincluding said linear inequality in said solution set; determining that said solution set including said linear inequality is a bounded solution set; identifying an additional event not being one of said one or more correlation events, said additional event having a first timestamp defined by said second clock; and using said bounded solution set to determine a second timestamp from said first timestamp, said second timestamp being with respect to said first clock.