Ara es mostren els items 21-40 de 45

    • Effective amplification of real WDM burst traffic using optical gain clamping 

      Zannin, Marcelo; Taccheo, Stefano; Ennser, Karin; Careglio, Davide; Solé Pareta, Josep (2008-05-04)
      Text en actes de congrés
      Accés obert
      Experimental studies of real optical burst traffic in WDM systems are performed with optical gain clamping for stabilizing the EDFA amplification. Impairments of power variation due to burst are shown to be negligible.
    • 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)
      Article
      Accés obert
      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 ...
    • Extending the flexgrid optical core towards the edges 

      Velasco Esteban, Luis Domingo; Ruiz Ramírez, Marc; Castro Casales, Alberto; Comellas Colomé, Jaume (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      National IP/MPLS network have being designed on top of fixed-grid DWDM optical networks so to spread out covering large areas. Besides, multilayer IP/MPLS-over-DWDM networks take advantage from grooming to achieve high ...
    • Fairness-based dynamic sub-carrier assignment for real time services in OFDMA networks 

      Bezerra Rodrigues, Emanuel; Casadevall Palacio, Fernando José (VDE Conference Publications, 2014)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Fairness is a crucial aspect for resource allocation in wireless systems, particularly in the downlink of 4G Orthogonal Frequency Division Multiple Access (OFDMA)-based systems. Therefore, it would be interesting for network ...
    • Field-Trial of a high-budget, filterless, lambda-to-the-user, UDWDM-PON enabled by an innovative class of low-cost coherent transceivers 

      Presi, Marco; Artiglia, Massimo; Bottoni, Fabio; Cano Valadez, Iván Nicolás; Tabares Giraldo, Jeison; Velásquez Micolta, Juan Camilo; Ghasemi, Saeed; Polo Querol, Víctor; Chu Guang, Yong; Prat Gomà, Josep Joan (2017-09-01)
      Article
      Accés obert
      We experimentally demonstrate an innovative ultradense wavelength division multiplexing (UDWDM) passive optical networks (PON) that implements the full ¿-to-the-user concept in a filterless distribution network. Key element ...
    • Grade of service in UDWDM-PON with statistical wavelength subscribing 

      Segarra Mullerat, Josep; Sales Zaragozá, Vicente; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The Grade of Service (GoS) or ONU rejection probability in coherent UDWDM-PONs with ONU lasers under limited tunability is evaluated. Each active ONU is assigned an exclusive wavelength channel, which is managed by heuristic ...
    • High resolution DFB laser tuning for optical spectrum analysis in access networks 

      Zamora Rovira, Xavier (Universitat Politècnica de Catalunya, 2022-06-16)
      Projecte Final de Màster Oficial
      Accés obert
      The project revolves around the development of a low-cost, high-performance Optical Spectrum Analyzer (OSA) for Passive Optical Networks (PON). From the study of the mathematical model of the laser used for the sweeping ...
    • Introduction to IP over WDM 

      Spadaro, Salvatore; Careglio, Davide; Aracil Rico, Javier; Fernández Palacios, Juan Pedro; Jajszczyk, Andrzej; Larrabeiti, David; López, Víctor; Masip Bruin, Xavier; Sánchez López, Sergio (Springer, 2009-06-01)
      Capítol de llibre
      Accés restringit per política de l'editorial
      The simple idea of having IP traffic directly transported over optical Wavelength Division Multiplexing (WDM) technology (“Internet Protocol (IP) over WDM”) has been envisioned as the future for the telecommunication ...
    • Lightpath fragmentation for efficient spectrum utilization in dynamic elastic optical networks 

      Pagès Cruz, Albert; Perelló Muntan, Jordi; Spadaro, Salvatore (Institute of Electrical and Electronics Engineers (IEEE), 2012)
      Text en actes de congrés
      Accés obert
      The spectrum-sliced elastic optical path network (SLICE) architecture has been presented as an efficient solution for flexible bandwidth allocation in optical networks. An homologous problem to the classical Routing and ...
    • Long-term provisioning of radio resources based on their utilization in dense OFDMA networks 

      Lagén Morancho, Sandra; Muñoz Medina, Olga; Pascual Iserte, Antonio; Vidal Manzano, José; Agustín de Dios, Adrián (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      This paper presents long-term resource provisioning schemes for dense multi-cell OFDMA-based networks, where multiple cells with possibly overlapping coverage areas compete for the same set of resources. The optimization ...
    • Multi-stream transmission in MIMO-FBMC systems 

      Caus López, Marius; Pérez Neira, Ana Isabel (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      This paper addresses the design of MIMO precoding and decoding techniques for the filter bank multicarrier (FBMC) modulation. Existing solutions give satisfactory performance in scenarios with high coherence bandwidth ...
    • Multilevel direct DFB phase modulation in 6.25 GHz spectrally spaced UDWDM PONs 

      Cano Valadez, Iván Nicolás; Velásquez Micolta, Juan Camilo; Polo Querol, Víctor; Prat Gomà, Josep Joan (2016)
      Presentació
      Accés restringit per política de l'editorial
      Direct phase modulation of DFB is demonstrated with DPSK, DQPSK and Duobinary modulation formats and detected with an intradyne receiver based on a 120-degree hybrid. The system is tested in a 50 km fibre link with 6.25 ...
    • Optimum carrier to signal power ratio for remote heterodyne DD-OFDM in PONs 

      Cano Valadéz, Iván Nicolás; Santos Blanco, M. Concepción; Prat Gomà, Josep Joan (2013-07)
      Article
      Accés restringit per política de l'editorial
      The carrier to signal power ratio (CSPR) in a directdetection optical orthogonal frequency division multiplexing (OFDM) system based on remote heterodyne scheme is optimized in a passive optical network (PON) downlink. ...
    • Orthogonal Frequency Division Multiplexed Access for Passive Optical Networks: a hands-on training approach 

      Peralta Gallardo, Ángel (Universitat Politècnica de Catalunya, 2012-07-27)
      Projecte Final de Màster Oficial
      Accés obert
      [ANGLÈS] Research activities for new alternatives in ultra fast transmission over optical fiber networks are looking towards Orthogonal Frequency Division Multiplexing (OFDM) which is used in different modern communication ...
    • Performance degradation of an OFDM-MIMO system with imperfect channel state information at the transmitter 

      Pascual Iserte, Antonio; Pérez Neira, Ana Isabel; Lagunas Hernandez, Miguel A. (2003)
      Text en actes de congrés
      Accés obert
      In this paper we analyze the performance degradation of a communications system combining the Orthogonal Frequency Division Multiplexing (OFDM) modulation with the simultaneous use of an array of antennas at both the ...
    • Rayleigh backscattering rejection in single-laser homodyne transceiver for UD-WDM using λ-Shifting 

      Masanas Jiménez, Miquel; Santos Blanco, M. Concepción; Tabares Giraldo, Jeison; Polo Querol, Víctor; Prat Gomà, Josep Joan (2021-04-01)
      Article
      Accés obert
      With the aim of using a single laser per transceiver in single fiber splitter-based passive optical networks (PON) with coherent homodyne receivers, we apply wavelength shifting in an ultra-dense wavelength division ...
    • Real burst traffic amplification in optically gain clamped amplifier 

      Ennser, Karin; Taccheo, Stefano; Careglio, Davide; Solé Pareta, Josep; Aracil Rico, Javier (2008-02-24)
      Comunicació de congrés
      Accés obert
      Optical burst amplification in a gain-stabilized amplifier is theoretically investigated using real burst traffic data. The results show that excellent performance are obtained for WDM transmission with negligible interplay ...
    • Resource allocation in multi-antenna MAC networks: FBMC vs OFDM 

      Payaró Llisterri, Miquel; Pascual Iserte, Antonio; García Armada, Ana; Sánchez Fernández, Matilde (2011)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      This paper addresses the problem of resource allocation in a multiple access channel where several mobile terminals (MT’s) are transmitting simultaneously to a single receiving base station, all of them with multiple ...
    • Restoration in optical cloud networks with relocation and services differentiation 

      Natalino da Silva, Carlos; Wosinska, Lena; Spadaro, Salvatore; Costa, J. C. W. A.; Frances, Carlos; Monti, Paolo (Institute of Electrical and Electronics Engineers (IEEE), 2016-02-01)
      Article
      Accés obert
      Optical cloud networks allow for the integrated management of both optical and IT resources. In this paradigm, cloud services can be provisioned in an anycast fashion; i.e., only the source node asking for a service is ...
    • Robust non-linear precoding for downlink multiuser multiple-input multiple-output orthogonal frequency-division multiplexing systems with limited feedback 

      Font Segura, Josep; Su, Y.; Wang, Xiaodong (2012-08-14)
      Article
      Accés restringit per política de l'editorial
      The authors consider the robust Tomlinson–Harashima precoding (THP) for downlink multiuser multiple-input multiple-output orthogonal frequency-division multiplexing systems with quantised feedback. The authors discuss ...