Field experience with fiber-in-the-loop systems: reliability performance

The authors address reliability issues from the perspective of accumulated experience with first-generation fiber-in-the-loop systems which have been serving customers for over three years. This experience indicates that the reliability of the service delivered by these systems, which depends on the quality built into them through quality assurance in the design and manufacturing processes and on their proactive maintenance means, is comparable to that of existing digital loop carrier systems. The active double star is found to be inherently more reliable than its passive counterpart. Comparison of projected and actual failure rates indicates that existing reliability-assessment procedures are overly conservative