Ricciardi, S.; Wang, J.; Palmieri, F.; Careglio, D.; Dittmann, L. Transactions on emerging telecommunications technologies Vol. 26, num. 2, p. 231-249 DOI: 10.1002/ett.2815 Data de publicació: 2015-02-01 Article en revista
Despite the significant degree of technological maturity reached by large-scale optical transmission infrastructures, new critical issues are emerging as side effects associated to their energy consumption, environmental impact and related costs, now accounting for an important part of the networks' operational expenditures. To face this problem, we propose a single-stage routing and wavelength assignment scheme, based on several network engineering extensions to the Generalised Multi-Protocol Label Switching (GMPLS) control plane protocols, mainly Open Shortest Path First, with new composed metrics and information transport facilities. It is structured according to a simple multi-objective optimisation approach aiming at containing the network's energy consumption and ecological impact while balancing the overall load and maintaining an acceptable connection demand satisfaction rate. The proposed solution is able to operate effectively in wide area wavelength routing scenarios, where multiple heterogeneous equipment, ranging from pure photonic to opaque routing/switching, amplification and regeneration devices are deployed in a GMPLS-empowered network. Copyright (c) 2014 John Wiley & Sons, Ltd.
Tomkos, I.; Azodolmolky, S.; Solé-Pareta, J.; Careglio, D.; Palkopoulou, E. Proceedings of the IEEE Vol. 102, num. 9, p. 1317-1337 DOI: 10.1109/JPROC.2014.2324652 Data de publicació: 2014-09-01 Article en revista
Rigid fixed-grid wavelength division multiplexing (WDM) optical networks can no longer keep up with the emerging bandwidth-hungry and highly dynamic services in an efficient manner. As the available spectrum in optical fibers becomes occupied and is approaching fundamental limits, the research community has focused on seeking more advanced optical transmission and networking solutions that utilize the available bandwidth more effectively. To this end, the flexible/elastic optical networking paradigm has emerged as a way to offer efficient use of the available optical resources. In this work, we provide a comprehensive view of the different pieces composing the 'flexible networking puzzle' with special attention given to capturing the occurring interactions between different research fields. Only when these interrelations are clearly defined, an optimal network-wide solution can be offered. Physical layer technological aspects, network optimization for flexible networks, and control plane aspects are examined. Furthermore, future research directions and open issues are discussed.
Careglio, D.; Papadimitriou, D.; Agraz, F.; Sahhaf, S.; Perello, J.; Tavernier, W.; Spadaro, S.; Colle, D. IEEE Global Internet Symposium p. 79-84 DOI: 10.1109/INFCOMW.2014.6849172 Data de presentació: 2014-04-28 Presentació treball a congrés
In this paper, we report our development experience and experimentation studies of two multicast routing schemes for the Internet, namely, PIM-SSM and GCMR. We detail their implementation over the Quagga open source routing suite, as well as their experimentation tests over a large-scale topology that reproduces the Internet characteristics.
Pedrola, O.; Ruiz, M.; Velasco, L.; Careglio, D.; González de Dios , O.; Comellas, J. Computers & operations research Vol. 40, num. 12, p. 3174-3187 DOI: 10.1016/j.cor.2011.10.026 Data de publicació: 2013-12 Article en revista
In this paper we deal with the survivable internet protocol (IP)/multi-protocol label switching (MPLS)-over-wavelength switched optical network (WSON) multi-layer network optimization problem (SIMNO). This problem entails planning an IP/MPLS network layer over a photonic mesh infrastructure whilst, at the same time, ensuring the highest availability of services and minimizing the capital expenditures (CAPEX) investments. Such a problem is currently identified as an open issue among network operators, and hence, its solution is of great interest. To tackle SIMNO, we first provide an integer linear programming (ILP) formulation which provides an insight into the complexity of its managing. Then, a greedy randomized adaptive search procedure (GRASP) with path-relinking (PR) together with a biased random-key genetic algorithm (BRKGA) are specifically developed to help solve the problem. The performance of both heuristics is exhaustively tested and compared making use of various network and traffic instances. Numerical experiments show the benefits of using GRASP instead of BRKGA when dealing with highly complex network scenarios. Moreover, we verified that the use of GRASP with PR remarkably improves the basic GRASP algorithm, particularly in real-sized, complex scenarios such as those proposed in this paper.
Sócrates-Dantas, J.; Careglio, D.; Melo Silveira, R.; Ruggiero, W.; Solé-Pareta, J. International Conference on Transparent Optical Networks p. Th.B4.1-1-Th.B4.1-4 DOI: 10.1109/ICTON.2013.6603062 Data de presentació: 2013-06 Presentació treball a congrés
Recently, Spectrum Switched Optical Networks (SSON) have been receiving much interest from the research community due to their network performance benefits. Some of these benefits include the possibility of enabling either super channels or sub-wavelength channels, which meet better the granularity of Internet needs. Due to its specific routing and resource assignment characteristics, SSON's primordial procedures, as routing and spectrum assignment (RSA), cannot be suitably assisted by current related protocols from Wavelength Switched Optical Network (WSON). For this very reason, a SSON control plane architecture and protocols should be extended from WSON's control plane in order to be able to support specific information exchange. This paper presents the most recent Path Computation Element (PCE) architecture extension proposals in the literature, which intend to meet SSON specific requirements.
Pedrola, O.; Careglio, D.; Klinkowski, M.; Solé-Pareta, J.; Bergman, K. Journal of optical communications and networking Vol. 5, num. 2, p. 104-115 DOI: 10.1364/JOCN.5.000104 Data de publicació: 2013-01-07 Article en revista
Translucent optical networks have emerged as potential yet feasible candidates to bridge the gap between the opaque and transparent network architectures. By allowing electrical 3R signal regeneration only at selected points in the network, translucent architectures represent a
cost-effective, power-ef¿cient solution. Concurrently, forecasts
predicting highly dynamic traf¿c patterns make it crucial for next-generation transport networks to engage highly agile technologies that include sub-wavelength switching (SWS). In translucent SWS networks, contention resolution is achieved through the still technologically immature all-optical wavelength converters (WCs). Since WCs are expected to be expensive, power-consuming devices, there has been significant research effort on devising WC-sharing architectures, which aim at minimizing the number of these devices in the network. WC sharing, however, requires complex switching fabrics that involve a much higher number of optical gates and stronger degradation due to physical layer impairments (more electrical 3R regenerators). It is clear, then, that the technological interest in WC-sharing architectures mainly depends on the cost trade-offs existing between these three components.
Pedrola, O.; Bathula, B.G.; Wang, M.; Ahsan, A.; Careglio, D.; Bergman, K. IEEE Global Communications Conference p. 2889-2895 DOI: 10.1109/GLOCOM.2012.6503555 Data de presentació: 2012-12 Presentació treball a congrés
The existing dimensioning strategy for translucent, sub-wavelength switching architectures relies on over-provisioning, and consequently, overuse of costly, power-consuming optical-electrical-optical (O/E/O) regenerators. In addition, due to a variety of external phenomena, many physical layer impairments are time-varying, and hence, can strongly degrade network performance. In this work, we introduce a Cross-Layer Optical Network Element (CLONE) used for the dynamic management of physical layer impairments in the network. We investigate the impact of real-time impairment aware routing in a CLONE-enabled optical network with sub-wavelength switching. Simulation results show that the CLONE-enabled network architecture provides improvements in: (1) energy efficiency by optimizing the usage of regenerators, and (2) network performance in terms of the packet loss probability.