Patent ID: 7487229
Filing Date: 2009-02-03
Classification: H04J

Abstract:
1. A method to synchronize local time at a node in a computer network with a reference time source, the method comprising determining a sequence of time sample pairs, wherein each time sample pair in the sequence of time sample pairs comprises a local time measurement based on at least one corresponding local time stamp generated by the node and a respective reference time measurement based on at least one corresponding reference time stamp generated by the reference time source; determining a plurality of cubic splines, wherein each cubic spline in the plurality of cubic splines interpolates between two respective time sample pairs in the sequence of time sample pairs; and mapping a local time value associated with the node to a corresponding reference time value associated with the reference time source based on the plurality of cubic splines, wherein mapping the local time value to the corresponding reference time value comprises: selecting one of a sequence of non-overlapping intervals corresponding to the local time value, wherein the selected time interval includes the local time value; selecting one of the plurality of cubic splines corresponding to the selected interval; and evaluating the selected cubic spline at the local time value to determine the reference time value corresponding to the local time value.