METHODS AND APPARATUS FOR LINE SWITCHING, CORRELATING DATA STREAMS AND CLOCK REGENERATION

摘要

A method of correlating data streams by generating tags based upon the data contained within blocks of the data streams and correlating the tags to align the data streams. There is further disclosed a method for selecting the most reliable data stream by generating tags associated with blocks of data that represent the quality of the data and/or line conditions and selecting the data stream having the tag with the best value. Historical tag values may also be used to control switching. There is also disclosed a method of generating an outgoing clock signal derived from switched time shifted incoming data streams. In the method timing signals are obtained from first and second data streams and relatively time shifted to align the timing signals. In this way either the first timing signals or time delayed second timing signals can alternately be used to generate an outgoing clock signal. Apparatus for implementing the methods is also disclosed.