Reliability evaluation of wdm networks with link capacity and hop constraints

A reliability evaluation module is presented for study of WDM network reliability. In this module, WDM networks are assumed to consist of three kinds of network elements nodes, links and wavelength channelrelated elements. And a network performance index – network ‘function value’, was introduced here as a quantitative representation of working-state of WDM network under certain link capacity and hop requirements. In addition, WDM networks here are assumed to be a survivable network, which can operate in a degradative manner against destruction and thus have multiple working-states instead of two opposite states. The reliability evaluation module was used to analyse the reliability of a WDM network with CERNET topology. Simulation results indicate that different link capacity requirement as well as different working-state requirements may lead to different reliability evaluation results, and the differences will enlarge very quickly with the increasing of network element failure rates. This implies that the study of WDM network reliability should be performed under multiple working-states assumption and the addition of the new network element kind a wavelength channel-related element is necessary.