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.