Dynamic grooming and spectrum allocation in optical metro ring networks with flexible grid

The metro section of telecom networks is currently pressured by a strong increase of traffic required by end users. Especially mobile end users are adopting new media-rich services that require high bandwidth. These users are characterized by a geographical mobility this mobility induces significant changes in the traffic pattern at metro level. So future metro networks are expected not only to provide very large capacities but also to support sudden (dynamic) changes of the traffic pattern. An optical metro network based on the concept of flexible spectrum grid can address such requirements in terms of bandwidth and flexibility. In this paper we show the benefits of employing a flexible grid in metro ring networks compared to a fixed-grid WDM case, under dynamic (changing) traffic. The adoption of flexible grid enables an effective spectrum utilization resulting in network blocking a few orders of magnitude lower with respect to fixed grid case.