Self-healing link switched ring for ATM traffic

A method for communicating information over a BLSR SONET line switched ring having a plurality of communication terminals connected over a first and a second transmission line, the method comprising the steps of:

• at each terminal, inserting an outgoing signal onto said first transmission line along a first direction of transmission defined from said terminal towards the first adjacent terminal, inserting said outgoing signal onto said second transmission line along a second direction of transmission defined from said terminal towards a second adjacent terminal;
• at each said terminal, receiving an incoming signal over said first transmission line from said first adjacent terminal, along said first direction of transmission, and from said second adjacent terminal along said second direction of transmission;
• and
• operating said plurality of communication terminals according to a unidirectional protection protocol upon detection of a failure condition in said incoming signal,
• wherein said incoming signal comprises an incoming non-ATM STS-W and an incoming ATM STS-Mc multiplexed in an incoming STS-N, and said outgoing signal comprises an outgoing non-ATM STS-W and an outgoing ATM STS-Mc, multiplexed in an outgoing STS-N, where M+W=N, and N, M, and W are integers indicative of the rates of said respective signals,
• wherein said unidirectional protection protocol operates according to a variant of a BellCore GR-1230-CORE standard.