Enabling Service Level Agreement-Differentiated Protection in C+L Multiband Optical Networks

Band division multiplexing (BDM) is a promising technology to upgrade the capacity of elastic optical networks (EON). By using both C and L bands instead of just the C-band, networks can support a larger number of connections. This paper presents and analyzes a set of novel strategies to ensure resiliency in multiband optical networks leveraging the unique characteristics of these networks and their amplifiers. We investigate two new protection methods for these networks, erbium-doped fiber amplifier (EDFA) protection and hybrid protection, and compare them with two established protection techniques, dedicated path protection (DPP) and shared backup path protection (SBPP). Recognizing that protection requirements vary among services, we also propose a service level agreement (SLA) differentiated protection mechanism that combines these strategies. High-priority clients receive robust protection against single failures of fibers or EDFAs through DPP or SBPP, while low-priority clients are safeguarded at least against EDFA failures via EDFA or hybrid protection. Our studies explore the most effective combinations of these techniques across various scenarios, demonstrating the advantages of SLA-differentiated protection over the utilization of a single classical protection method for all clients. Furthermore, we propose and analyze a more flexible protection mechanism that allows clients to divide their traffic into two segments: one requiring a high level of protection and the other a lower level. This flexibility enhances the protection options available, enabling a finer categorization of user needs and making it an attractive choice for network operators.