Virtualization of elastic optical networks and regenerators with traffic grooming

Abstract

An elastic optical network (EON) plays an important role in transport technology for virtualization of networks.A key aspect of EONs is to establish lightpaths (virtual links) with exactly the amount of spectrum that is needed and with the possibility of grooming, the process of grouping many small traffic flows into larger units, creating a super-lightpath. Grooming eliminates the need for many guard bands between lightpaths and also saves transceivers; however, it often leads to the need to perform O/E/O conversions to multiple-data-rate optical signals at intermediate nodes. The aim of this paper is to provide a mixed-integer linear programming (MILP) formulation, as well as heuristic and meta-heuristic approaches, for the design of multiple virtual optical networks (VONs) in an elastic optical substrate network with bandwidth-variable lightpaths, modulation format constraints and virtual elastic regenerator placement. Traffic grooming is allowed inside each VON and a distance-adaptive modulation-format technique is employed to guarantee efficiency in terms of bandwidth for a physical substrate, subject to several virtual topologies. A reduced (EQ2) MILP formulation without grooming capability is also proposed for comparison. The complete MILP formulation jointly solves the virtual topology design, the regenerator placement, grooming as well as the routing, modulation and spectrum assignment (RMSA) problems. The reduced (EQ2) MILP formulation, heuristics and meta-heuristic, on the other hand, separate the virtual topology design problem from the RMSA problem. It is shown that the grooming approach can provide good results, since it solves the problem for a complete design when compared to the approach without grooming. Furthermore, heuristic solutions for large networks are proposed, which present good performance (in terms of saving spectrum) for the design with large instances.

Squeezed Protection in Elastic Optical Networks Subject to Multiple Link Failures

“…Despite the proven benefits of grooming, previous studies have not treated in much detail the combination of routing (single or multiple paths) and protection with grooming and RSA. In particular, with grooming, it may not be feasible to set up virtual links with protection between all node pairs due to a limited number of resources such as optical transmitters, receivers or regenerators [18]. Therefore, there still remain important challenges regarding grooming and virtualization in optical networks with protection, mainly with the 5th generation of mobile networking (5G) on our doorstep, and [19] provides evidence to support our claim for a detailed study in that area.…”

Optimized Traffic Grooming through modified PSO based Iterative Hungarian algorithm in Optical Networks

“…Optimal use of network resources and survivability of data was contributed by the allotted path protection provided and traffic grooming strategies [18]. Assis et al utilized the mixed-integer linear programming [1] with heuristic and meta-heuristic approaches which was used for the virtual optical networks (VONs) design. Traffic adjustments were allowed within each VON, and a Distance adaptive modulation method was used to ensure optimal performance focusing on physical substrate bandwidth.…”