SLA-Aware Protocol for Efficient Tunable Laser Utilization to Support Incremental Upgrade in Long-Reach Passive Optical Networks

With the advances in optical technology, the span of a broadband access network using passive optical network (PON) technology can be increased from today´s standard of 20 km to 100 km or higher and thereby serve many more users. Such an extended-reach PON is known as a SuperPON in the literature, and we call it a long-reach PON (LR-PON). A major challenge in LR-PON is how to utilize the network resources (e.g., wavelengths, lasers, etc.) effectively to meet the increased bandwidth requests from the expanding base of users. We propose a new and efficient protocol to achieve a high utilization of tunable lasers across different user groups in LR-PON. To accommodate downstream bursty traffic and provide quality of service in the user-specified service-level agreements (SLAs), the protocol integrates our proposed SLA-aware bandwidth allocation scheme based on flow scheduling. Illustrative numerical results demonstrate the protocol´s advantage to support incremental upgrade of bandwidth with increasing user bandwidth requests and to provide a user with an SLA that guarantees a number of streaming flows with average bandwidth and maximum delay guarantee (i.e., 5 ms), as well as data flows with average bandwidth specifications.