Multiple technologies in a single access platform

Parallel development of DLC (Digital Loop Carrier) and FITL (Fiber-In-The-Loop) technologies and tbt introduction of SONET (Synchronous Optical NETwork) or SDH (Synchronous Digital Hierarchy) in the loo! have led many access system suppliers to develop new multi-functional network elements, which we refer to a Multiple Technologies Access Terminals (MTATs). Such MTATs may have a SONET interface on the feede side (supporting SONET transport to the wire center) and both fiber and copper terminations on the line side (supporting DLC and FITL applications). This is only one example of an MTAT but it is the focus of this paper because it is a real product of several suppliers and the issues associated with its appearance in the marketplace demand immediate attention. While each technology component of an MTAT may conform to the applicable generic requirements or public standards, there are cases where the appropriate requirements for a specific MTK configuration are unclear. The result is that MTAT products may not fully interoperate and may jeopardize Mix-and-match. This paper explores some of the technology specific conflicts, gaps or overlaps in requirements.