A perspective on fiber in the loop systems

The current direction Bellcore is pursuing in the development of proposals for fiber-in-the-loop (FITL) system generic requirements is reviewed, and it is shown how the necessary tradeoffs are likely to be resolved. The reference model to be used in developing requirements for delivery of existing services and new services through FITL systems is discussed. The FITL system is defined in terms of the three external interfaces it must meet with the customer, the fiber-optic distribution network, and the larger Bellcore client company (BCC) transmission and operations networks. This reveals where innovation and product evolution can most profitably focus. Additional technical constraints that tend to narrow the technological and architectural choices available and set certain common directions for FITL systems are summarized. A generic interface between FITL systems and the larger BCC networks is proposed, and considerations for intervening transport and crossconnect systems are examined.<>