F-T in telecommunications networks: state, perspectives, trends

Public telecommunications networks make extensive use of fault-tolerant techniques in order to achieve high dependability. Part of this fault tolerance is embedded in the network architecture itself, or in the nature of the offered services, while some other part is explicitly added to increase the reliability and availability of specific network elements. The evolution toward integrated services digital networks (ISDN) and integrated broadband communications networks (IBCN) is now posing serious challenges and offering important opportunities to further increase this essential aspect of telecommunications. A brief review if presented of the basic characteristics of existing networks, and some of the major problems that are currently being addressed in relation to their expected evolution over the next 20 years are examined.<>