Local loop system evolution toward B-ISDN with an integrated MAN/DLC

A strategy is described for subscriber loop systems and architectures leading to broadband ISDN, from the service and economy viewpoints. Since remote multiplexing is the key function for offering initial broadband services as economically as 64-kb/s services, an integrated metropolitan area network/digital loop carrier (MAN/DLC) architecture and a distributed multiplexing scheme are proposed. This architecture supports the independent evolution of transport core networks and customer premises networks and equipment, at a cost comparable with an ordinary approach. Node architectures with the distributed multiplexing are discussed in terms of bus multiplexing, call processing, and LSI implementation. Feasibility studies of this architecture have been conducted with prototypes that incorporate three basic LSIs for the B-ISDN transmission convergence layer and the ATM (asynchronous transfer mode) layer