Predeployment of Regenerators for Fast Service Provisioning in DWDM Transport Networks [Invited]

Abstract

Dense wavelength division multiplexing (DWDM) transport networks are evolving to support dynamic setup/teardown of wavelength services. This is becoming possible mainly via node architectures with flexible add/drop port utilization, where an already deployed transponder can be tuned to any wavelength and configured to transmit/receive via any output/input direction, and advanced control and management software, which provide the means to remotely reconfigure equipment end to end. In long-haul networks, exploiting these capabilities to quickly set up new services also demands that 3R regenerators (performing reamplification, reshaping, and retiming) have been deployed in advance. This paper proposes a framework that, first, characterizes stochastically the fitness of each network node as a placeholder for predeployed regenerators based on the network and traffic information available and, second, distributes the set of regenerators to match as closely as possible the fitness values. Network simulation on a reference long-haul network under dynamic traffic is used to evaluate the effectiveness of four fitness estimation strategies, each based on a different set of forecasts about the expected network operating conditions. The results highlight that when the main assumptions embedded in these strategies hold during network operation significant benefits can be attained, in terms of lower service blocking probability and/or reduced number of predeployed 3R regenerators, by exploiting additional information when computing the node's fitness values.

Designing Transparent Flexible-Grid Optical Networks for Maximum Spectral Efficiency [Invited]

“…Given the limited size of this band, maximizing SE is key to avoiding, or at least postponing, capital-intensive investments in new fiber rollouts, additional optical inline amplifiers, and upgrade of ROADMs. However, network operators have to balance this objective with the need to minimize shorter-term capital expenditures, namely the ones with transponder/regenerator equipment required to support all traffic demands [10,11]. As a result, a transparent network design, where 3R regenerators are avoided, is preferred.…”

Predeployment of Transponders for Dynamic Lightpath Provisioning in Translucent Spectrally–Spatially Flexible Optical Networks

“…The reported results showed that the MSU-RP algorithm outperformed all previous approaches. In Reference [18], four strategies for regenerator predeployment in WDM network were presented, starting with a basic uniform distribution of regenerators followed by three topology-based methods that can be enriched with information on network traffic.…”

“…Uniform location (UNI) assumes that each node is assigned with the same number of transponders [18]:…”

“…Nodal degree (ND) assumes that transponders are located proportionally to the degree of network node [18]:…”

Performance Analysis of WSS-Based ROADM With Shared-Per-Group Tunable Wavelength Converters

“…Contrary to the conventional ROADM, which adopts demux-switch-mux architectures to split and switch wavelengths in color and space respectively [2]- [5], the emergence of Wavelength Selective Switch (WSS) enables the ROADM to exchange wavelength channels in both domains simultaneously [6]- [10]. Since WSS can select arbitrary number of wavelengths from the input port to output fiber independent of wavelengths, the WSS based ROADMs avoids the unnecessary demux-mux process to split each wavelength channels into single instances.…”