Optimal spare capacity design for various protection switching methods in ATM networks

With the employment of very high capacity transmission systems in high-speed broadband networks (B-ISDN, broadband integrated services digital network), based upon the asynchronous transfer mode (ATM), the consequences of a link failure have increased, since even during a short disconnection a large volume of data is lost. These networks can be made safer against failure, if in the case of a transmission link outage the affected traffic is routed over still intact network parts. This paper describes various protection switching methods for ATM networks and presents mathematical models which can be used to determine globally optimal restoration paths and to dimension spare capacities in the network. Finally, the results are discussed and the various methods are compared.