Robust jitter-free remote clock offset measuring method
US8139489B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 2008 |
| Grant date | Mar 20, 2012 |
| Priority date | — |
| Expiry date | Sep 5, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/0667
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A clock offset between a client and a server is measured by: (a) the client sending a request to the server; (b) upon receiving the request in step (a), the server optionally sending a server acknowledgement to the client; (c) upon the client receiving the server acknowledgement in step (b) or directly, if no acknowledgement was used, each of the client and the server proceeding to concurrently exchange their respective timestamps with each other a multiplicity (n) of times, thus forming a multiplicity (n) of timestamp exchanges; and (d) determining a plurality of apparent forwards and backwards delays based on the multiplicity (n) of timestamp exchanges. The preferred apparent forwards and backwards delays are then selected based on the minimum values (for each direction) determined in (d) above. The clock offset between client and server is then determined based on the preferred apparent forwards and backwards delays.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.