Local area networks based on fiber optic technology

LAN architectures are presented which are based on the concept of channel switching with a simplified communication protocol suite. These architectures are specifically designed to take advantage of the capabilities of fiber-optic technology. The distinctive feature of these LANs is a simplified protocol suite with a physical layer network interface and an end-to-end layer-2 protocol. This results in a network interface that is considerably less complex than the standard approach, where the user/network interface covers three layers. Other features of the LANs include: use of passive optical components where practical; similar treatment of voice, data, and video, which facilitates integration of communication functions; separation of control signals and data; separation of network versus user functions; expandability of local stations and external connections; and straightforward interfaces, modeled after the ISDN primary interface, to wide-area networks