Provisioning of Survivable Multicast Sessions in Wavelength-Routed Optical Networks With Scheduled Traffic

摘要

Provisioning survivable multicast sessions in wavelength-routed optical networks has already been studied under static or dynamic traffic. However, in many practical cases, customers tend to require a large bandwidth at a specified time interval. Scheduled traffic model, in which the setup and teardown times are known in advance or vary in a specified larger time window, is more appropriate to characterize this kind of traffic. In this paper, two scheduled traffic models are formulated and investigated for multicast protection in wavelength-routed optical networks, namely, Fixed Scheduled Traffic Model (FSTM) and Sliding Scheduled Traffic Model (SSTM). With the guaranteed 100% restorability against any single link failure, the FSTM formulation can achieve a global minimum cost for establishing all multicast sessions. A two-step optimization approach is further proposed to deal with the survivable multicast provisioning problem under SSTM. By optimizing the network resources jointly in space and time, survivable multicast sessions can be provisioned at much lower costs.