Patent · US Expired

Synchronization of asynchronous data signals

US4928275A · kind A · utility

64Cited by
9References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 26, 1989
Grant dateMay 22, 1990
Priority date
Expiry dateMay 26, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04J3/076
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A method of and apparatus for synchronizing an asynchronous DS1 signal to produce a synchronized signal in the SONET format is described. The asynchronous signal is stuffed in dependence upon a stuff request signal which is produced from a comparison with a threshold level of a phase difference between read and write phases with which the synchronized and asynchronous signals are respectively read from and written into an elastic store. The phase detection and threshold comparison are effected synchronously with the respective signals. To this end, the read address for the store is latched in synchronism with the synchronized frames, and its difference from the write address and the resulting threshold level comparison is effected in synchronism with the write clock for the store and hence with the asynchronous signal. The synchronizer provides a reduced waiting time jitter in the synchronized signal.

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