Physical layer impairment aware routing (PLIAR) in WDM optical networks: issues and challenges

Abstract

Abstract-In WDM optical networks, the physical layer impairments (PLIs) and their significance depend on network type-opaque, translucent, or transparent; the reach-access, metro, or core/long-haul; the number and type of network elements-fiber, wavelengths, amplifiers, switching elements, etc.; and the type of applications-real-time, non-real time, missioncritical, etc. In transparent optical networks, PLIs incurred by non-ideal optical transmission media accumulate along an optical path, and the overall effect determines the feasibility of the lightpaths. If the received signal quality is not within the receiver sensitivity threshold, the receiver may not be able to correctly detect the optical signal and this may result in high bit-error rates. Hence, it is important to understand various PLIs and their effect on optical feasibility, analytical models, and monitoring and mitigation techniques. Introducing optical transparency in the physical layer on one hand leads to a dynamic, flexible optical layer with the possibility of adding intelligence such as optical performance monitoring, fault management, etc. On the other hand, transparency reduces the possibility of client layer interaction with the optical layer at intermediate nodes along the path. This has an impact on network design, planning, control, and management.Hence, it is important to understand the techniques that provide PLI information to the control plane protocols and that use this information efficiently to compute feasible routes and wavelengths. The purpose of this article is to provide a comprehensive survey of various PLIs, their effects, and the available modeling and mitigation techniques. We then present a comprehensive survey of various PLI-aware network design techniques, regenerator placement algorithms, routing and wavelength assignment algorithms, and PLI-aware failure recovery algorithms. Furthermore, we identify several important research issues that need to be addressed to realize dynamically reconfigurable next-generation optical networks. We also argue the need for PLI-aware control plane protocol extensions and present several interesting issues that need to be considered in order for these extensions to be deployed in real-world networks.Index Terms-Wavelength division multiplexing, wavelengthrouted optical networks, routing and wavelength assignment, optical performance monitoring, optical layer service level agreements, transmission impairments, quality of transmission, physical layer impairment aware routing, impairment constraintbased routing, regenerator placement algorithms, physical layer impairment aware control plane, GMPLS-based WDM networks, and IP over WDM networks.

Regenerator Location Problem and survivable extensions: A hub covering location perspective

“…The interested reader can refer to Savasini et al (2007), Ouyang et al (2005), Yang and Ramamurthy (2005a) and Saradhi and Subramaniam (2009) for studies that investigate the RLP with a focus on different aspects such as blocking probabilities in dynamic optical networks with wavelength division multiplexing.…”

Physical Layer Impairments Aware OVPN Connection Selection Mechanisms

“…The degradation of OVPNC quality happens due to the effect of Physical layer impairment (PLI) constraints. PLIs are broadly classified in to two categories: linear and non-linear impairments [3]. The terms linear and non-linear in fiber optics mean intensity-independent and intensity-dependent, respectively.…”

“…We termed this as OVPN control manager (OVPNCM), which can be centralized or distributed. In our design we consider a centralized base OVPNCM, which considers network layer as well as physical layer impairment constraints [3] - [5] in order to obtain a guaranteed service for a client application. Such application might require a wide range of QoS guarantees from the SP.…”

Metodologia de controle adaptativo de ganho para amplificadores ópticos em redes WDM dinâmicas

“…As penalidades não-lineares ocorrem tanto pela variação do índice de refração do meio com a intensidade de potência óptica, como é o caso dos três primeiros, quanto por meio dos fenômenos de espalhamento inelásticos, que também surgem com altos níveis de potência e que é o caso dos dois últimos fenômenos [26], cuja diferença é que fônons acústicos participam do SBS, enquanto fônons ópticos estão envolvidos no SRS [27].…”

“…A primeira utiliza modelos analíticos para estimar as penalidades e a segunda utiliza resultados simulados, experimentais ou técnicas de monitoramento em tempo real. O monitoramento em tempo real abrange medidas das penalidades (optical impairment monitoring, OIM) como potências de entrada e saída de um amplificador, dispersão residual ou total e medidas de desempenho completo da rede (optical performance monitoring, OPM) como parâmetros de BER, OSNR e fator de qualidade [4,26].…”