Capacity Utilization of Protecting WDM Optical Networks for Unicast and Multicast Traffic

With the extremely high volume of traffic carried on wavelength division multiplexing (WDM) networks, survivability becomes increasingly critical in managing high speed networks. In a WDM network, the failure of network element (i.e. fiber links, and cross connects) may cause the failure of several optical channels, thereby leading to large data loss. Here the different approaches are investigated to protect mesh based WDM optical networks for such failure and subsequently, a mathematical model for capacity utilization for unicast traffic is presented. In this paper survivable schemes, such as path protection/restoration and link protection/restoration are reviewed for unicast as well as for multicast traffic. In addition to the shared link risk group (SLRG) based shared path protection (SLRG-SPP) and SLRG-based shared link protections (SLRG-SLP) are also discussed. It is observed that, the shared-path protection is more efficient in terms of capacity utilization over dedicated-path protection schemes and shared-link protection schemes, for random traffic demands. For low optical cross connect (OXC) configuration time (10 ns) the shared-link protection, scheme, offers better protection-switching time than the path-protection scheme. Taking high OXC configuration time (10 ms), the dedicated-path protection scheme has a better protection-switching time than the shared-path and shared-link protection.