Design of a SONET/ATM-based optical customer premises network

A novel optical customer premises network (CPN), H-Bus, has been designed to interface future B-ISDN (broadband integrated services digital network) signals and distribute available bandwidth to terminal equipment connected to the CPN. Key features of this network are the use of optical fiber as transmission medium, and a hybrid architecture, namely a broadcast bus for the downstream traffic (network interface to subscriber terminal to network interface). The physical layer of the network makes use of the synchronous optical network (SONET) transmission format. The user information is carried using the asynchronous transfer mode (ATM) technique. The reliability of H-Bus is improved through the use of a new optical element to protect the CPN in the case of terminal failures. To resolve any access contention on the upstream bus, a new media-access control protocol has been designed to effectively achieve fairness