4B/5B block code to SONET OC-3 (155-Mbit/s) interface for ATM local area networks
T.J. Robe, T.C. Banwell, J. Hodge, JW Mann, W. E. Stephens · 1993
Evolving standards for high-speed LAN’s' beyond 100 Mbit/s include asynchronous-transfer-mode (ATM) payload multiplexing and physical-layer interfaces based on the block-coding technology embodied in the FDDI and Fiber Channel standards.2 To connect these LAN’s to the public broad-band ISDN network a SONET3 interface is needed. This paper describes an experimental research prototype physical-layer interface that implements a full-duplex block code to SONET conversion. The prototype is an important research aid in helping to understand the issues that arise when a high-speed asynchronous line protocol is interfaced to a synchronous line protocol. Figure 1 shows the typical architecture for a broad-band ATM LAN. The workstations in this network connect to ATM switches through the 11 interface, which may often be a 4B/5B block-coded interface similar to that used in FDDI. The 12 interfaces between switches can also be 4B/5B. The interface to the public network (13) will be a SONET interface at either the STS-3 (155 Mbit/s) or STS-12 (622 Mbit/s) level.