Patent · US Expired

System and method for synchronizing clocks in distributed computer nodes

US5907685A · kind A · utility

91Cited by
7References
65Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 4, 1995
Grant dateMay 25, 1999
Priority date
Expiry dateAug 4, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04J3/0667
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Described herein is a distributed computer system having a plurality of computer nodes arranged logically adjacent to each other in a communications ring. Each computer node receives communications from a preceding computer node and sends communications to a succeeding computer node. The computer nodes maintain individual local clocks with local time values c. The clocks are synchronized to each other through a sequence of distributed processing steps. The steps include a step of measuring an approximate local offset d of the local time value of each computer node relative to the local time value of a logically adjacent computer node in the communications ring. A subsequent step includes passing a plurality of collation variables from a lead computer node, through the computer nodes forming the communications ring, and back to the lead computer node in a single pass. The collation variables are processed at each computer node as they are passed around the communications ring. This processing is based at least in part on the measured approximate local offsets d at each computer node. The lead computer then calculates a difference m between its local time value and the mean of the lo…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.