Differentiated Quality of Service in Survivable WDM Mesh Networks

The emerging next generation optical transport WDM networks, with reconfigurable optical switches, offer a promising solution to the ever-increasing demand for high bandwidth and flexible connectivity. In order to meet the needs of such a demand, the trend in current backbone and access network development is moving toward a unified solution that will support different classes of service such as voice, data, and a large range of multimedia applications. However, those applications come with different qualities of service (i.e., bandwidth, reliability, and availability) depending on their requirements and on how much the users are willing to pay for the services. In the design of protection schemes in survivable WDM networks, there is a trade-off to be set between the capacity efficiency and the quality of service parameters. Differentiation of the provided quality of service can help in finding an appropriate trade-off between network cost and quality of service, for both service providers and customers. In this paper, we propose different network design optimization models in order to optimize two quality of service (QoS) protection parameters: Protection capacity sharing and recovery delay. We use shared protection schemes based on pre-configured structures that are pre-cross connected ahead of failures, and that are dynamically reconfigured in case of a failure. The resulting optimization models are solved using large scale optimization tools in order to ensure scalable solutions. Comparisons are conducted on different network and traffic instances, and a thorough analysis is made, exploring the added values of pre-cross connected protections structures on protection QoS.