Exploració per autor "Tomkos, Ioannis"

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    • A comparative study of impairments aware optical networks planning tools 

      Azodolmolky, Siamak; Angelou, Marianna; Tomkos, Ioannis; Morea, Annalisa; Pointurier, Yvan; Solé Pareta, Josep (2010)
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      Transparent and translucent optical networks are widely considered as the prime candidates for the core network technology of the future. These networks provide ultra high speed end-to-end connectivity with high quality ...

    • A novel impairment aware RWA algorithm with consideration of QoT estimation inaccuracy 

      Azodolmolky, Siamak; Pointurier, Yvan; Angelou, Marianna; Careglio, Davide; Solé Pareta, Josep; Tomkos, Ioannis (IEEE Press. Institute of Electrical and Electronics Engineers, 2011-04)
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      In all-optical networks the physical layer impairments accumulate along a lightpath and also vary dynamically, and a number of impairment aware routing and wavelength assignment (IA-RWA) techniques have been proposed in ...

    • A novel monitor placement algorithm for accurate performance monitoring in optical networks 

      Angelou, Marianna; Pointurier, Yvan; Azodolmolky, Siamak; Careglio, Davide; Spadaro, Salvatore; Tomkos, Ioannis (2011)
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      We propose a novel monitor placement algorithm that reduces significantly the number of monitors required to accurately assess the QoT of all lightpaths established in an optical network, compared to other monitor placement ...

    • A novel offline physical layer impairments aware RWA algorithm with dedicated path protection consideration 

      Azodolmolky, Siamak; Klinkowski, Miroslaw; Pointurier, Yvan; Angelou, Marianna; Careglio, Davide; Solé Pareta, Josep; Tomkos, Ioannis (2010-10-15)
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      Physical layer impairments accumulate as light propagates through a lightpath in the transparent optical networks. Therefore, it is possible to provision a lightpath, while its quality of transmission (QoT) does not meet ...

    • A survey on physical layer impairments aware routing and wavelength assignment algorithms in optical networks 

      Azodolmolky, S; Klinkowski, Miroslaw; Marín Tordera, Eva; Careglio, Davide; Solé Pareta, Josep; Tomkos, Ioannis (2009-03)
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      Optical networks are moving from opaque and translucnet architectures towards all-optical (transparent) architecutres. In translucent architectures a small amount of regeneration (e.g. optical-electronic-optical conversion) ...

    • An OFDMA-PON with non-preselected independent ONU sources and centralized feedback wavelength control: Dimensioning and experimental results 

      Cano Valadéz, Iván Nicolás; Santos Blanco, M. Concepción; Escayola Elias, Francisco Javier; Polo Querol, Víctor; Giacoumidis, E.; Kachris, C.; Tomkos, Ioannis; Prat Gomà, Josep Joan (IEEE, 2012)
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      A simple and low cost method for wavelength control based on centralized OLT monitoring and feedback of economical random non-preselected independent ONU sources is presented. The technique was dimensioned and experimentally ...

    • Colorless FDMA-PON with flexible bandwidth allocation and colorless, low-speed ONUs [invited] 

      Schindler, Philipp C.; Schmogrow, Rene M.; Dreschmann, Michael; Meyer, Joachim; Tomkos, Ioannis; Prat Gomà, Josep Joan; Krimmel, Heinz-Georg; Pfeiffer, Thomas; Kourtessis, Pandelis; Ludwig, A.; Karnick, D.; Hillerkuss, David; Becker, Juergen; Koos, Christian; Freude, Wolfgang; Leuthold, Juerg (Institute of Electrical and Electronics Engineers (IEEE), 2013-10)
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      We demonstrate a remotely seeded flexible passive optical network (PON) with multiple low-speed subscribers but only a single optical line terminal transceiver operating at a data rate of 31.25 Gbits/s. The scheme is based ...

    • Control and management requirements for a coherent ultra-dense WDM PON for lambda to the user access networks 

      Ververidis, Christopher; Tomkos, Ioannis; Klonidis, Dimitrios; Rafel, Albert; Parkin, Neil; Urban, Patryk; Prat Gomà, Josep Joan; Segarra Mullerat, Josep (Institute of Electrical and Electronics Engineers (IEEE), 2014)
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      In this paper we first highlight the arising MAC-layer requirements for a coherent ultra-dense WDM PON for full and shared lambda to the user access networks. We then report on the appropriate modifications of the XGPON ...

    • Demonstration and field trial of a resilient hybrid NG-PON test-bed 

      Prat Gomà, Josep Joan; Polo Querol, Víctor; Schrenk, Bernhard; Lázaro Villa, José Antonio; Bonada Bo, Francesc; López Pastor, Eduardo Tommy; Omella, M.; Saliou, Fabienne; Trung Le, Quang; Chanclou, Philippe; Leino, D.; Soila, Risto; Spirou, S.; Costa, Liliana; Teixeira, A.; Tosi-Beleffi, G.M.; Klonidis, Dimitrios; Tomkos, Ioannis (2014-10-01)
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      A multi-layer next generation PON prototype has been built and tested, to show the feasibility of extended hybrid DWDM/TDM-XGPON FTTH networks with resilient optically-integrated ring-trees architecture, supporting broadband ...

    • Demonstration of a remotely dual-pumped long-reach PON for flexible deployment 

      Chanclou, Philippe; Schrenk, Bernhard; Lázaro Villa, José Antonio; Klonidis, Dimitrios; Bonada Bo, Francesc; Saliou, Fabienne; Polo Querol, Víctor; López Pastor, Eduardo Tommy; Le, Q.T.; Brenot, Romain; de Valicourt, Guilhem; Spirou, S.; Soila, Risto; Leino, D.; Tosi Beleffi, Giorgio M.; Tomkos, Ioannis; Chatzi, Sotiria; Teixeira, A.; Costa, L.; Kazmierski, Christophe; Prats, Jordi (2012-04-01)
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      We propose and experimentally demonstrate a flexible wavelength division multiplexing/time division multiplexing network architecture for converged metro-access environment. Entire passiveness in the fiber plant is ...

    • Dynamic impairment-aware optical networking: some experimental results of the EU DICONET project 

      Spadaro, Salvatore; Perelló Muntan, Jordi; Agraz Bujan, Fernando; Angelou, Marianna; Azodolmolky, Siamak; Qin, Yixuan; Nejabati, Reza; Simeonidou, Dimitra; Tomkos, Ioannis (2011)
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      The paper presents some results from the experimental validation of the achievements of the EU DICONET project. Specifically, the DICONET test-bed is presented and the experiments conducted for the performance evaluation ...

    • Evaluation of the impact of different SDM switching strategies in a network planning scenario 

      Shariati, Mohammad Behnam; Sayyad Khodashenas, Pouria; Rivas Moscoso, José Manuel; Ben Ezra, Shalva; Klonidis, Dimitrios; Jiménez, Felipe; Velasco Esteban, Luis Domingo; Tomkos, Ioannis (Institute of Electrical and Electronics Engineers (IEEE), 2016)
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      We compare SDM joint and independent switching strategies in a planning scenario involving a European backbone network. Joint switching can achieve cost savings of 40-50% with a performance similar to that of independent ...

    • Experimental comparison of impairment-aware RWA algorithms in a GMPLS-controlled dynamic optical network 

      Angelou, Marianna; Agraz Bujan, Fernando; Kokkinos, Panagiotis; Perelló Muntan, Jordi; Azodolmolky, Siamak; Varvarigos, Emmanouel; Spadaro, Salvatore; Tomkos, Ioannis (2011)
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      The European research project DICONET proposed and implemented a multi-plane impairment-aware solution for flexible, robust and cost-effective core optical networks. The vision of DICONET was realized via a set of cross-layer ...

    • Experimental demonstration of a statistical OFDM-PON with multiband ONUs and elastic bandwidth allocation 

      Cano Valadéz, Iván Nicolás; Escayola Elias, Francisco Javier; Schindler, Philipp C.; Santos Blanco, M. Concepción; Polo Querol, Víctor; Leuthold, Juerg; Tomkos, Ioannis; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2015-01-01)
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      The statistical orthogonal frequency division multiplexing passive optical network (OFDM-PON) concept with multiband optical network units (ONUs) is experimentally tested with two users and an optical line terminal at 2.5/5 ...

    • Experimental demonstration of centralized and distributed impairment-aware control plane schemes for dynamic transparent optical networks 

      Tomkos, Ioannis; Gunkel, Mathias; Varvarigos, Manos; Kokkinos, Panagiotis; Pointurier, Yvan; Agraz Bujan, Fernando; Azodolmolky, Siamak; Angelou, Marianna; Perelló Muntan, Jordi; Velasco Esteban, Luis Domingo; Spadaro, Salvatore; Francescon, Antonio; Saradhi, Chava (IEEE Computer Society Publications, 2010)
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      In transparent optical networks, the signal experiences the impact of various phenomena that degrade its quality. Considering the impact of physical layer impairments (PLIs) on transparent [1] and highly dynamic optical ...

    • Experimental evaluation and improvement methods for low cost transmitters in long reach PONs 

      Chatzi, Sotiria; Klonidis, Dimitrios; Tsekrekos, Christos P.; Lázaro Villa, José Antonio; Prat Gomà, Josep Joan; Tomkos, Ioannis (2013-12)
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      In this paper, we first analyze the degradation stochastic resonance (DSR) effect in the context of adaptive averaging (AD-AVG) architectures. The AD-AVG is the adaptive version of the well-known AVG architecture . It is ...

    • Experimental evaluation of path restoration for a centralised impairment-aware GMPLS-controlled all-optical network 

      Tomkos, Ioannis; Agraz Bujan, Fernando; Perelló Muntan, Jordi; Angelou, Marianna; Azodolmolky, Siamak; Velasco Esteban, Luis Domingo; Spadaro, Salvatore; Kokkinos, Panagiotis; Varvarigos, Emmanouel (IEEE Computer Society Publications, 2010)
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      This paper evaluates a centralised impairment-aware path restoration approach for GMPLScontrolled transparent optical networks. Experimental results on a 14-node network test-bed show successful QoT compliant path restoration ...

    • Flexible WDM-PON with Nyquist-FDM and 31.25 Gbit/s per wavelength channel using colorless, low-speed ONUs 

      Schindler, Philipp C.; Schmogrow, Rene M.; Dreschmann, Michael; Meyer, Joachim; Hillerkuss, David; Tomkos, Ioannis; Prat Gomà, Josep Joan; Krimmel, Heinz-Georg; Pfeiffer, Thomas; Kourtessis, Pandelis; Becker, Juergen; Koos, Christian; Freude, Wolfgang; Leuthold, Juerg (Institute of Electrical and Electronics Engineers (IEEE), 2013)
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      A remotely seeded flexible WDM network solution with 31.25 Gbit/s based on Nyquist sinc-pulses is demonstrated. The low-speed, colorless ONUs use remote heterodyne detection with electrical up- and down-conversion and SOAs ...

    • Free space intra-datacenter interconnection utilizing 2D optical beam steering 

      Shariati, Mohammad Behnam; Bogris, A.; Dijk, P.V.; Roeloffzen, C.; Tomkos, Ioannis; Syvridis, D (Institute of Electrical and Electronics Engineers (IEEE), 2018)
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      We evaluate the performance and benefits of novel integrated Free-Space-Optics (FSO) transceivers, supporting optical beam steering at low power consumption with ns steering speed. A proper intra-datacenter network ...

    • GPON unbundling for multioperator access 

      Carmona, David; Prat Gomà, Josep Joan; Tomkos, Ioannis; PILAR, SANCHEZ MARCO (Institute of Electrical and Electronics Engineers (IEEE), 2010)
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      This work aims at considering different unbundling options for the Local Loop Unbundling (LLU) in order to provide multi-operator access and consider the economical impact for the FTTH NGA entrants to deploy such alternatives. ...