Method and system for clock offset and skew estimation

Patent metadata

Field	Value
Publication number	US-8959381-B2
Application number	US-201213603977-A
Country	US
Kind code	B2
Filing date	Sep 5, 2012
Priority date	Sep 5, 2012
Publication date	Feb 17, 2015
Grant date	Feb 17, 2015

Abstract

This invention relates to methods and devices for clock offset and skew estimation. The invention has particular application in the alignment of slave clocks to a master clock. In embodiments of the invention, the slave clock employs an independent free running clock and a recursive estimation technique to estimate the clock offset and clock skew between the slave and master clocks. The slave can then use the offset and skew to correct the free running clock to reflect an accurate image of the master clock.

First claim

The invention claimed is:

1. A method of estimating the offset and skew of a local clock in a time client compared with a remote master clock in a time server, the method including the steps of:
transmitting Sync and Delay Req messages under the IEEE 1588 PTP, carrying timestamps from the time server;
receiving said messages at the time client and recording the time of receipt according to the local clock and extracting said timestamps; and
performing a recursive estimation us…

Assignees

• Aweya James
• Alsindi Nayef
• Univ Khalifa Science Technology & Res
• British Telecomm
• Emirates Telecomm Corp

Inventors

• Aweya James
• Alsindi Nayef

Classifications

• G06F1/04 Primary

  Physics · mapped topic

• G06F1/14

  Physics · mapped topic

• H04J3/0667

  Electricity · mapped topic

• H04L43/087

  Electricity · mapped topic