Optimal relocation of excess capacity in optical WDM backbone networks

Operational networks get gradually upgraded to avoid capacity exhaustion and create resources to handle traffic growth. These upgrades require installation of new physical resources (e.g., line cards) and might be costly to network operators. The additional capital expenditure (CapEx) to upgrade the network can be reduced or eliminated by relocating excess resources which were deployed into the network, but are unused (e.g., due to optimistic forecasts or excessive overprovisioning). We investigate a cost-effective scheme to relocate excess capacity in an optical WDM backbone network to (i) reduce or eliminate upgrade costs, (ii) avoid capacity exhaustion (by migrating resources from underutilized links to overutilized links), and (iii) improve network robustness (by migrating resources from unreliable links to reliable links). We propose a novel generic relocation scheme that network operators can use based on their objectives to determine how to relocate excess resources. We also provide a solution which maximizes various benefits (e.g., network robustness and capacity exhaustion avoidance) of network operators by using game theory for our relocation scheme. Our results show that network operator can save a lot of CapEx while upgrading/improving the network by using our relocation scheme.