Ara es mostren els items 37-56 de 85

    • Learning from the optical spectrum: failure detection and identification [Invited] 

      Shariati, Mohammad Behnam; Ruiz Ramírez, Marc; Comellas Colomé, Jaume; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2018-07-23)
      Article
      Accés obert
      The availability of coarse-resolution cost-effective Optical Spectrum Analyzers (OSA) allows its widespread deployment in operators’ networks. In this paper, we explore several machine learning approaches for soft-failure ...
    • Learning from the optical spectrum: soft-failure identification and localization 

      Velasco Esteban, Luis Domingo; Shariati, Mohammad Behnam; Vela, Alba P.; Comellas Colomé, Jaume; Ruiz Calvo, Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The availability of coarse-resolution cost-effective Optical Spectrum Analyzers (OSA) allows its widespread deployment in operators' networks. In this paper, several machine learning approaches for failure identification ...
    • Man-in-the-middle attacks through re-shaping I-Q optical constellations 

      Ruiz Ramírez, Marc; Comellas Colomé, Jaume; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2023)
      Text en actes de congrés
      Accés obert
      A module to re-shape optical constellations making the optical signal resembles as it has traversed some distance is presented. Armed with this module, Main-in-the-Middle attacks can be performed, which could be undetectable ...
    • Minimum channel spacing in an ofdm cpfsk optical coherent system 

      Prat Gomà, Josep Joan; Comellas Colomé, Jaume; Junyent Giralt, Gabriel (1998-03)
      Article
      Accés restringit per política de l'editorial
      Channel spacing in optical frequency-division multiplexed (OFDM) coherent optical systems with continuous-phase frequency-shift-keying (CPFSK) is obtained both theoretically and experimentally. The bit error ratio is derived ...
    • Mixed integration of CDIO skills into telecommunication engineering curricula 

      Sayrol Clols, Elisa; Bragós Bardia, Ramon; Alarcón Cot, Eduardo José; Cabrera-Bean, Margarita; Calveras Augé, Anna M.; Comellas Colomé, Jaume; O'Callaghan Castellà, Juan Manuel; Pegueroles Vallés, Josep R.; Pla, Enrique; Prat Viñas, Lluís; Sáez Moreno, Germán; Sardà Ferrer, Joan; Tallon Montoro, Carme (2010)
      Article
      Accés obert
      Spain has been intensively involved in designing engineering curricula for the last two years and next academic year all engineering schools will be deploying all bachelor programs adapted to the EHEA and to the Spanish ...
    • ML-aided SOP compensation to increase key exchange rate in QKD systems 

      Ahmadian, Seyed Morteza; Ruiz Ramírez, Marc; Comellas Colomé, Jaume; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2023)
      Text en actes de congrés
      Accés obert
      Secure communications have become a requirement for virtually all kind of applications. Currently, two distant parties can generate shared random secret keys by using public key cryptography. However, quantum computing ...
    • Modeling the routing and spectrum allocation problem for flexgrid optical networks 

      Velasco Esteban, Luis Domingo; Klinkowski, Miroslaw; Ruiz Ramírez, Marc; Comellas Colomé, Jaume (2012-12)
      Article
      Accés restringit per política de l'editorial
      Flexgrid optical networks are attracting huge interest due to their higher spectrum efficiency and flexibility in comparison with traditional wavelength switched optical networks based on the wavelength division multiplexing ...
    • Modified duobinary polarization-shift keying transmission scheme 

      Gené Bernaus, Joan M.; Soler Rocasalbas, Marçal; Contreras Leyva, Miguel A.; Comellas Colomé, Jaume; Prat Gomà, Josep Joan (2003)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      A new version of duobinary polarization-shift keying scheme is proposed. The relocation of the duobinary filter at the receiver side and the optimization of both transmitter and receiver electrical filters offer a receiver ...
    • Motivations and outcomes: a study of an intensive international course 

      Myrup Pedersen, Jens; Gutiérrez López, José Manuel; Kirikova, Marite; Zabludowski, Lukasz; Comellas Colomé, Jaume (Tempus Publications, 2017-05-10)
      Article
      Accés restringit per política de l'editorial
      In this paper, we study what motivates students and university teachers to do intensive international courses, and how they evaluate the outcomes. The study is based on three years of an Erasmus funded Intensive Programme ...
    • NORMA: Network Operator Revenues Maximization 

      Velasco Esteban, Luis Domingo; Ruiz Ramírez, Marc; Comellas Colomé, Jaume; Junyent Giralt, Gabriel (IEEE, 2012)
      Text en actes de congrés
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      A great part of core network operators’ gross profit comes from the provisioned connectivity services. In this work, we analyze the provisioning of differentiated services in current Shared Path Protection (SPP) environments. ...
    • On the benefits of FMF based data center interconnection utilizing MIMO-less PAM-M transceivers 

      Shariati, Mohammad Behnam; Diamantopoulos, Nikolaos-Panteleimon; Klonidis, Dimitrios; Comellas Colomé, Jaume; Tomkos, Ioannis (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      Space division multiplexing (SDM) has been proposed to cost-effectively increase the capacity of optical transmission systems. The cost savings can be realized by introducing some levels of spatial integration of elements. ...
    • On the benefits of multi-path recovery in flexgrid optical networks 

      Castro Casales, Alberto; Velasco Esteban, Luis Domingo; Comellas Colomé, Jaume; Junyent Giralt, Gabriel (2014-12-01)
      Article
      Accés restringit per política de l'editorial
      We propose a new recovery scheme, called multi-path recovery (MPR), specifically designed for flexgrid-based optical networks. It combines protection and restoration schemes to jointly recover, in part or totally, the ...
    • On the performance of dynamic source aggregation of sub-wavelength connections in EONs 

      Sayyad Khodashenas, Pouria; Comellas Colomé, Jaume; Perelló Muntan, Jordi; Spadaro, Salvatore; Junyent Giralt, Gabriel (Institute of Electrical and Electronics Engineers (IEEE), 2014)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      In elastic optical networks, heterogeneous traffic demands are typically supported by a single type of bandwidth-variable transmitters, which is not always spectrum and cost efficient. In light of this, we recently proposed ...
    • On the performance of flexgrid-based optical networks 

      Velasco Esteban, Luis Domingo; Ruiz Ramírez, Marc; Pedrola Escribà, Òscar; Castro Casales, Alberto; Klinkowski, Miroslaw; Careglio, Davide; Comellas Colomé, Jaume (Institute of Electrical and Electronics Engineers (IEEE), 2012)
      Text en actes de congrés
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      The ever increasing IP traffic volume has finally brought to light the high inefficiency of current wavelength-routed rigid-grid networks in matching the client layer requirements. Such an issue results in the deployment ...
    • Optical interconnection for datacenters: To switch or not to switch 

      Comellas Colomé, Jaume; Junyent Giralt, Gabriel (Institute of Electrical and Electronics Engineers (IEEE), 2023)
      Text en actes de congrés
      Accés obert
      Optical interconnection is seen as a promising solution to alleviate the congestion problems inside datacenters. Previously reported studies focus solely on optical circuit switching to establish connections. In this work ...
    • Optical network net present value optimization in shared path protection environments 

      Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo; Comellas Colomé, Jaume; Junyent Giralt, Gabriel (IEEE Press. Institute of Electrical and Electronics Engineers, 2011)
      Text en actes de congrés
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      Network operators are facing hard competition for opportunities in the telecommunications market, thus network investments must be carefully evaluated from the costs and revenues viewpoint before the decision making ...
    • Optimized traffic profile for FlexGrid optical networks 

      Liu, Fengqing; Comellas Colomé, Jaume (2017-05-05)
      Article
      Accés obert
      This work is focused on studying the connections’ bandwidth distribution effects on the FlexGrid network performance. An accurate study of spectrum occupancy in heavy loaded FlexGrid optical networks is carried out. This ...
    • Optimizing link spectrum occupancy in elastic optical networks 

      Comellas Colomé, Jaume; Ruiz Ramírez, Marc; Junyent Giralt, Gabriel (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Text en actes de congrés
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      This work focuses on spectrum assignment in Elastic Optical Networks. The accurate study about spectrum occupancy in a flexgrid link is carried out. As a result, the probability values of finding different connection sizes ...
    • Options for cost-effective capacity upgrades in backbone optical networks 

      Shariati, Mohammad Behnam; Rivas Moscoso, José Manuel; Klonidis, Dimitrios; Tomkos, Ioannis; Ben Ezra, Shalva; Jiménez, Felipe; Marom, Dan M.; Sayyad Khodashenas, Pouria; Comellas Colomé, Jaume; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Text en actes de congrés
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      Upgrading the capacity of backbone optical networks while delivering contents to the end-users with a reduced cost per bit is a day-by-day challenge of network operators. In this paper, we first discuss several mid-term ...
    • Path-based recovery in flexgrid optical networks 

      Castro Casales, Alberto; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo; Junyent Giralt, Gabriel; Comellas Colomé, Jaume (IEEE, 2012)
      Text en actes de congrés
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      With the advent of flexgrid optical networks, the rigid wavelength-division multiplexing (WDM) technology will be enhanced by providing better spectrum efficiency and flexibility. In those future flexible optical networks, ...