Future Backbone Optical Networks: Fiber Densification Versus Network Densification

The increasing amount of traffic being aggregated to the terrestrial backbone optical networks (BONs) from the metro/access communication networks has caused capacity crunch in the BONs. Increasing coverage with rural and remote connectivity, wireless network densification, data hungry 5G applications, and increasing datacenters (DCs) are among the major factors that necessitated the deployment of huge amount of optical fibers around the world to connect cell sites, to interconnect DCs, to provide fiber to the home (FTTH) services, among others. Due to massive fiberization in the metro/access networks and hence to handle the increased traffic being aggregated to BONs through them, efforts are being made to increase the capacity of BONs via novel devices, fiber designs, and spectral/spatial flexibility and expansion along with the additional deployment of fibers (referred to as fiber densification) in BONs. In this paper, we focus on the topological aspect of BON and present BON densification as an approach to enable the realization of several advanced optical network technologies in BONs. We analyze the advantages of BON densification considering multicore fibers (MCFs) for which low transmission reach has been the main hindrance towards its deployment in BONs. Simulations indicate that through BON densification, MCF networks can achieve significantly low blocking, and high resiliency against multi-link failures. Furthermore, we highlight several other aspects of future communication networks which indicate that BON densification is a promising approach as compared to the conventional fiber densification.