Quality of service based protection in optical networks using diversity constraint

In this paper, we present a simple approach towards providing quality of service based partial protection in optical networks. We use a diversity based protection mechanism to ensure that in the event of link/node failures, a fraction of demand is always survived. To determine routing of optical paths while honoring restrictions such as wavelength continuity and exclusivity restriction, switching capability of OXCs, etc., we present a mixed-integer linear program formulation. Due to large size of the formulation, we develop an accompanied solution approach based on Lagrangian relaxation and sub-gradient optimization. We then present numerical results towards impact of diversity constraint upon the survivability, switch size, and number of carried wavelengths. Using them, we also show that optical networks based on sparse graphs might require higher number of wavelengths per fiber and the switching capacity of the OXCs to ensure higher values of fraction of accepted demands.