Time and data synchronization between network devices
US7542485B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2004 |
| Grant date | Jun 2, 2009 |
| Priority date | — |
| Expiry date | Aug 18, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2213/13396
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
To synchronize time between network devices equally capable of accurately maintaining an indication of current time, one of the network devices is deemed to be a reference for time and the other network devices synchronize their indications of current time to the reference. To synchronize copies of data at multiple network devices, each network device maintains a counter representative of the passage of time but not necessarily of current time. The counter at each device is periodically synchronized with the counters of other network devices. When data is changed at a network device, the value of the counter at the time of changing is stored in association with the changed data. Stored counter values are used to determine whether a local copy or a remote copy of the data is likely more recent and therefore preferable. A further test may be applied if a counter value comparison is inconclusive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.