http://hdl.handle.net/2117/2039 Mon, 20 May 2013 09:28:43 GMT 2013-05-20T09:28:43Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19350 Title: ONU optimal gain and position of the distribution element in Rayleigh-limited WDM and TDM PONs with reflective ONU Authors: López Pastor, Eduardo Tommy; Lázaro Villa, José Antonio; Arellano Pinilla, Cristina; Polo Querol, Víctor; Prat Gomà, Josep Joan Abstract: The influence of the distribution element position in PONs is reported. Best Crosstalk-to-Signal ratio (C/S) is achieved if it is placed either in the ONU or OLT vicinity with optimum ONU gain depending of the MUX position Fri, 17 May 2013 14:55:56 GMT http://hdl.handle.net/2117/19350 2013-05-17T14:55:56Z López Pastor, Eduardo Tommy; Lázaro Villa, José Antonio; Arellano Pinilla, Cristina; Polo Querol, Víctor; Prat Gomà, Josep Joan no The influence of the distribution element position in PONs is reported. Best Crosstalk-to-Signal ratio (C/S) is achieved if it is placed either in the ONU or OLT vicinity with optimum ONU gain depending of the MUX position http://hdl.handle.net/2117/19277 Title: Planning and designing FTTH networks: elements, tools and practical issues Authors: Segarra Mullerat, Josep; Sales Zaragoza, Vicente; Prat Gomà, Josep Joan Abstract: Fiber-To-The Home (FTTH) provides the offered and new broadband services. Now it is deployed massively worldwide with Passive Optical Networks (PONs), being the EPON and GPON standards the most used. In this paper we consider solutions for planning and designing such optical fiber access networks from the point of view of an incumbent operator; taking into account components administration, mapping tools, design applications and automation resources; therefore, managing infrastructures, materials, geography, houses,buildings and users databases. The networks will be dynamic, so the proposed designs and utilities must also be active to reach thousands of passed homes and to cover the life-cycle of the networks and not only the initial built. Thu, 16 May 2013 09:18:55 GMT http://hdl.handle.net/2117/19277 2013-05-16T09:18:55Z Segarra Mullerat, Josep; Sales Zaragoza, Vicente; Prat Gomà, Josep Joan no designing guidelines, Fiber-to-the-Home (FTTH), network planning, Passive Optical Networks (PONs), practical utilities Fiber-To-The Home (FTTH) provides the offered and new broadband services. Now it is deployed massively worldwide with Passive Optical Networks (PONs), being the EPON and GPON standards the most used. In this paper we consider solutions for planning and designing such optical fiber access networks from the point of view of an incumbent operator; taking into account components administration, mapping tools, design applications and automation resources; therefore, managing infrastructures, materials, geography, houses,buildings and users databases. The networks will be dynamic, so the proposed designs and utilities must also be active to reach thousands of passed homes and to cover the life-cycle of the networks and not only the initial built. http://hdl.handle.net/2117/19269 Title: Optical filter cascading effects in a phase modulated coherent optical OFDM transmission system based on Hartley transform Authors: Chochol, M.; Fabrega, J.M.; Svaluto Moreolo, Michela; Junyent Giralt, Gabriel Abstract: Effects of cascading optical filters are investigated for a phase modulated coherent optical OFDM system based on Hartley transform. The evaluation is performed by means of numeric simulations in a 10 Gb/s system with a total bandwidth of 10 GHz. First a back-to-back (no fiber) case is assessed. Results show a 3 dB power penalty after a single filter of only 68% of the signal bandwidth. The same penalty is achieved when cascading 10 filters of 21.6 GHz bandwidth. Additionally, the penalties associated to the introduction of fiber spans between filters are investigated. Wed, 15 May 2013 16:39:16 GMT http://hdl.handle.net/2117/19269 2013-05-15T16:39:16Z Chochol, M.; Fabrega, J.M.; Svaluto Moreolo, Michela; Junyent Giralt, Gabriel no Coherent detection, Filter cascading, flex grid, Optical OFDM, Phase modulation, WDM Effects of cascading optical filters are investigated for a phase modulated coherent optical OFDM system based on Hartley transform. The evaluation is performed by means of numeric simulations in a 10 Gb/s system with a total bandwidth of 10 GHz. First a back-to-back (no fiber) case is assessed. Results show a 3 dB power penalty after a single filter of only 68% of the signal bandwidth. The same penalty is achieved when cascading 10 filters of 21.6 GHz bandwidth. Additionally, the penalties associated to the introduction of fiber spans between filters are investigated. http://hdl.handle.net/2117/19250 Title: Path-based recovery in flexgrid optical networks Authors: Castro Casales, Alberto; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo; Junyent Giralt, Gabriel; Comellas Colomé, Jaume Abstract: 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, optical connections (lightpaths) can allocate a flexible number of spectrum slices, also known as frequency slots, so to match better with its requested bitrate. In this paper, we propose to take advantage of this flexible spectrum allocation in recovery mechanisms to be triggered when a failure occurs to provide recovery of part of the requested bitrate, i.e. the allocated spectrum by backup lightpaths could be lower than that of the working lightpaths provided that client service level agreements are fulfilled. This reduction in the recovered bitrate (bitrate squeezing) allows optimizing the use of network capacity. We propose path-based recovery alternatives, based on protection and restoration, specially designed for flexgrid networks. The performance of the proposed recovery mechanisms is exhaustively evaluated on a national reference network Wed, 15 May 2013 13:22:36 GMT http://hdl.handle.net/2117/19250 2013-05-15T13:22:36Z Castro Casales, Alberto; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo; Junyent Giralt, Gabriel; Comellas Colomé, Jaume no Bitrate squeezed recovery, Flexgrid Optical Networks, Network Optimization 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, optical connections (lightpaths) can allocate a flexible number of spectrum slices, also known as frequency slots, so to match better with its requested bitrate. In this paper, we propose to take advantage of this flexible spectrum allocation in recovery mechanisms to be triggered when a failure occurs to provide recovery of part of the requested bitrate, i.e. the allocated spectrum by backup lightpaths could be lower than that of the working lightpaths provided that client service level agreements are fulfilled. This reduction in the recovered bitrate (bitrate squeezing) allows optimizing the use of network capacity. We propose path-based recovery alternatives, based on protection and restoration, specially designed for flexgrid networks. The performance of the proposed recovery mechanisms is exhaustively evaluated on a national reference network http://hdl.handle.net/2117/19056 Title: Power efficiency of SARDANA and other long-reach optical acces networks Authors: Lovric, Ana; Aleksic, Slavisa; Lázaro Villa, José Antonio; Tosi Beleffi, Giorgio; Prat Gomà, Josep Joan; Polo Querol, Víctor Abstract: Different long-reach optical access networks are studied with respect to their power efficiency. Special focus is dedicated to the hybrid TDM/WDM PON proposed in the SARDANA project, in which remote amplification is utilized for reach extension. The structures of the remote nodes and subsystems for reach extension are shown and discussed. The influence of uplink capacity limitation on power efficiency is evaluated, i.e., the access networks' efficiencies are presented for different CO capacities in terms of Watt per user and per Gbit/s of user's bandwidth as a function of number of users connected to the CO. The results show remarkable power efficiency degradation for high-speed access technologies in case of strong uplink limitation, while for unlimited uplink case, 10G-EPON and SARDANA networks show the best efficiency. Description: Best Paper of ONDM'2011 Tue, 30 Apr 2013 11:55:24 GMT http://hdl.handle.net/2117/19056 2013-04-30T11:55:24Z Lovric, Ana; Aleksic, Slavisa; Lázaro Villa, José Antonio; Tosi Beleffi, Giorgio; Prat Gomà, Josep Joan; Polo Querol, Víctor no Different long-reach optical access networks are studied with respect to their power efficiency. Special focus is dedicated to the hybrid TDM/WDM PON proposed in the SARDANA project, in which remote amplification is utilized for reach extension. The structures of the remote nodes and subsystems for reach extension are shown and discussed. The influence of uplink capacity limitation on power efficiency is evaluated, i.e., the access networks' efficiencies are presented for different CO capacities in terms of Watt per user and per Gbit/s of user's bandwidth as a function of number of users connected to the CO. The results show remarkable power efficiency degradation for high-speed access technologies in case of strong uplink limitation, while for unlimited uplink case, 10G-EPON and SARDANA networks show the best efficiency. http://hdl.handle.net/2117/18977 Title: Demonstration of GMPLS-controlled device power management for next generation green optical networks Authors: Morea, Annalisa; Perelló Muntan, Jordi; Agraz Bujan, Fernando; Spadaro, Salvatore Abstract: We propose GMPLS protocol enhancements enabling dynamic power state management of optoelectronic network devices for setup-time-aware differentiated connection provisioning. Daily energy savings of 56% are demonstrated in a Pan-European-like network compared to always on scenarios. Wed, 24 Apr 2013 10:52:07 GMT http://hdl.handle.net/2117/18977 2013-04-24T10:52:07Z Morea, Annalisa; Perelló Muntan, Jordi; Agraz Bujan, Fernando; Spadaro, Salvatore no GMPLS protocol, Optoelectronic network, Energy savings We propose GMPLS protocol enhancements enabling dynamic power state management of optoelectronic network devices for setup-time-aware differentiated connection provisioning. Daily energy savings of 56% are demonstrated in a Pan-European-like network compared to always on scenarios. http://hdl.handle.net/2117/18499 Title: Low complexity bit rate variable transponders based on optical OFDM with PAPR reduction capabilities Authors: Nadal, Laia; Svaluto Moreolo, Michela; Fàbrega Sánchez, Josep Maria; Junyent Giralt, Gabriel Abstract: In this paper, we propose low complexity bit rate variable transponders for adaptive DC biased Optical OFDM systems. The transponders are based on an alternative transform, the fast Hartley transform (FHT), and use adaptively modulated O-OFDM (AMO-OFDM) to introduce flexibility to optical networks. Additionally, low complexity selective mapping (LC-SLM) technique is included in the bit rate variable transponders to mitigate the effects of the peak-to-average power ratio (PAPR)and reduce the clipping noise, enabling the use of low bias values. Fri, 22 Mar 2013 13:20:25 GMT http://hdl.handle.net/2117/18499 2013-03-22T13:20:25Z Nadal, Laia; Svaluto Moreolo, Michela; Fàbrega Sánchez, Josep Maria; Junyent Giralt, Gabriel no In this paper, we propose low complexity bit rate variable transponders for adaptive DC biased Optical OFDM systems. The transponders are based on an alternative transform, the fast Hartley transform (FHT), and use adaptively modulated O-OFDM (AMO-OFDM) to introduce flexibility to optical networks. Additionally, low complexity selective mapping (LC-SLM) technique is included in the bit rate variable transponders to mitigate the effects of the peak-to-average power ratio (PAPR)and reduce the clipping noise, enabling the use of low bias values. http://hdl.handle.net/2117/18402 Title: Optical subsystems for next generation access networks Authors: Lázaro Villa, José Antonio; Polo Querol, Víctor; Schrenk, Bernhard; Bonada Bo, Francesc; Cano Valadéz, Iván Nicolás; López, E.T.; Kazmierski, Christophe; de Valicourt, Guilhem; Brenot, Romain; Bauwelinck, Johan; Xing-Zhi, Qiu; Ossieur, P.; Forzati, Marco; Rigole, Jean-Pierre; Monroy, I.T; Tangdiongga, E.; Morant, Maryland; Nicolau, L.; Teixeira, A.L.; Erasme, D.; Klonidis, Dimitrios; Tomkos, Ioannis; Prat Gomà, Josep Joan; Kouloumentas,, Christos; Avramopoulos, Hércules Abstract: Recent optical technologies are providing higher flexibility to next generation access networks: on the one hand, providing progressive FTTx and specifically FTTH deployment, progressively shortening the copper access network; on the other hand, also opening fixed-mobile convergence solutions in next generation PON architectures. It is provided an overview of the optical subsystems developed for the implementation of the proposed NG-Access Networks. Tue, 19 Mar 2013 13:18:55 GMT http://hdl.handle.net/2117/18402 2013-03-19T13:18:55Z Lázaro Villa, José Antonio; Polo Querol, Víctor; Schrenk, Bernhard; Bonada Bo, Francesc; Cano Valadéz, Iván Nicolás; López, E.T.; Kazmierski, Christophe; de Valicourt, Guilhem; Brenot, Romain; Bauwelinck, Johan; Xing-Zhi, Qiu; Ossieur, P.; Forzati, Marco; Rigole, Jean-Pierre; Monroy, I.T; Tangdiongga, E.; Morant, Maryland; Nicolau, L.; Teixeira, A.L.; Erasme, D.; Klonidis, Dimitrios; Tomkos, Ioannis; Prat Gomà, Josep Joan; Kouloumentas,, Christos; Avramopoulos, Hércules no Recent optical technologies are providing higher flexibility to next generation access networks: on the one hand, providing progressive FTTx and specifically FTTH deployment, progressively shortening the copper access network; on the other hand, also opening fixed-mobile convergence solutions in next generation PON architectures. It is provided an overview of the optical subsystems developed for the implementation of the proposed NG-Access Networks. http://hdl.handle.net/2117/18273 Title: An OFDMA-PON with non-preselected independent ONU sources and centralized feedback wavelength control: Dimensioning and experimental results Authors: 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 Abstract: 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 tested in an OFDMA-PON with 1 Gb/s ONUs and 30 km of fibre along with the minimum optical spectral gap between consecutive ONU wavelengths. Results indicate that this method reduces the spectral overlap probability and increasing the number of users and cost-effectiveness of a PON, Wed, 13 Mar 2013 15:52:48 GMT http://hdl.handle.net/2117/18273 2013-03-13T15:52:48Z 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 no 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 tested in an OFDMA-PON with 1 Gb/s ONUs and 30 km of fibre along with the minimum optical spectral gap between consecutive ONU wavelengths. Results indicate that this method reduces the spectral overlap probability and increasing the number of users and cost-effectiveness of a PON, http://hdl.handle.net/2117/18107 Title: Routing protocol enhancements for power state engineering of green network elements Authors: Verchere, Dominique; Morea, Annalisa; Spadaro, Salvatore; Le Sauze, Nicolas Abstract: A routing protocol is enhanced to advertise the power state of node interfaces for wavelength switched optical networks to allow tuning the power consumption according to the data traffic demands. By engineering the different power states, GMPLS controlled nodes are configured to preserve the QoS of incoming traffic volumes such as reliability as well as the constraints of carrier grade networks, such as stability and operation costs. For variable incoming traffic reference models, more than half of the total power consumption required for an European optical networks without any power saving capabilities can be saved from powering the optoelectronic interfaces column. Wed, 06 Mar 2013 14:56:43 GMT http://hdl.handle.net/2117/18107 2013-03-06T14:56:43Z Verchere, Dominique; Morea, Annalisa; Spadaro, Salvatore; Le Sauze, Nicolas no A routing protocol is enhanced to advertise the power state of node interfaces for wavelength switched optical networks to allow tuning the power consumption according to the data traffic demands. By engineering the different power states, GMPLS controlled nodes are configured to preserve the QoS of incoming traffic volumes such as reliability as well as the constraints of carrier grade networks, such as stability and operation costs. For variable incoming traffic reference models, more than half of the total power consumption required for an European optical networks without any power saving capabilities can be saved from powering the optoelectronic interfaces column. http://hdl.handle.net/2117/17904 Title: Multiplatform virtual laboratory for engineering education Authors: Villar Zafra, Aitor; Zarza Sánchez, Sergio; Lázaro Villa, José Antonio; Fernández Canti, Rosa M. Abstract: An autonomous and multi platform virtual laboratory for educational purposes is presented. The implemented platform includes a server with a SSH(Secure SHeil)connection and a separated repository containing the virtual experiments. The programming of the experiments is implemented in Java language based tool, the EJS (Easy Java Simulation) and uses an external computation engine, for example MatIab. The virtual laboratory provides control system experimentsat University level. Two application examples are described, namely, a magnetic levitator and an inverted pendulum­ cart system. The virtual laboratory has been successfully used for education and training of Electronics Engineering students. A discussion of the results of this e-learning experience is also presented. Thu, 21 Feb 2013 10:24:01 GMT http://hdl.handle.net/2117/17904 2013-02-21T10:24:01Z Villar Zafra, Aitor; Zarza Sánchez, Sergio; Lázaro Villa, José Antonio; Fernández Canti, Rosa M. no An autonomous and multi platform virtual laboratory for educational purposes is presented. The implemented platform includes a server with a SSH(Secure SHeil)connection and a separated repository containing the virtual experiments. The programming of the experiments is implemented in Java language based tool, the EJS (Easy Java Simulation) and uses an external computation engine, for example MatIab. The virtual laboratory provides control system experimentsat University level. Two application examples are described, namely, a magnetic levitator and an inverted pendulum­ cart system. The virtual laboratory has been successfully used for education and training of Electronics Engineering students. A discussion of the results of this e-learning experience is also presented. http://hdl.handle.net/2117/17058 Title: WDM overlay of distributed base stations in deployed passive optical networks using coherent optical OFDM transceivers Authors: Fabrega, J.M.; Svaluto Moreolo, Michela; Chochol, M.; Junyent Giralt, Gabriel Abstract: It is proposed to reuse the deployed PON infrastructure by overlaying distributed radio base stations by means of very dense WDM with narrow channel spacings. In order to cope with that while minimizing its impact onto the performance of legacy equipment, coherent optical OFDM technology is used. Furthermore, the case of a practical implementation using CPRI is analyzed by means of simulations for several use cases. Within the analyzed use cases, a rural PON with 50 km reach has proven to support splitting ratios of up to 32 users, whereas an urban radio access network has been demonstrated to support ratios of up to 256 users within a radius of 2 km. Mon, 03 Dec 2012 10:43:38 GMT http://hdl.handle.net/2117/17058 2012-12-03T10:43:38Z Fabrega, J.M.; Svaluto Moreolo, Michela; Chochol, M.; Junyent Giralt, Gabriel no It is proposed to reuse the deployed PON infrastructure by overlaying distributed radio base stations by means of very dense WDM with narrow channel spacings. In order to cope with that while minimizing its impact onto the performance of legacy equipment, coherent optical OFDM technology is used. Furthermore, the case of a practical implementation using CPRI is analyzed by means of simulations for several use cases. Within the analyzed use cases, a rural PON with 50 km reach has proven to support splitting ratios of up to 32 users, whereas an urban radio access network has been demonstrated to support ratios of up to 256 users within a radius of 2 km. http://hdl.handle.net/2117/16936 Title: NORMA: Network Operator Revenues Maximization Authors: Velasco Esteban, Luis Domingo; Ruiz Ramírez, Marc; Comellas Colomé, Jaume; Junyent Giralt, Gabriel Abstract: 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. This analysis concludes that, with current resource assignment policies, only a very poor grade of service can be provided to the carried best effort traffic. Hence, we propose diff-WS, a resource partitioning scheme that differentiates those wavelengths supporting each class of service in the network. The benefits of diff-WS in front of current resource assignment policies are afterwards evaluated from an economic perspective. To this goal, we define the NORMA problem as a revenue maximization problem. To solve NORMA, we introduce statistical models to obtain, for a given grade of service, the highest traffic intensity for each supported class of service and resource assignment scheme. From the numerical results, we show that diff-WS maximizes resource utilization in the network and, thus, network operator’s profit. Fri, 16 Nov 2012 11:28:35 GMT http://hdl.handle.net/2117/16936 2012-11-16T11:28:35Z Velasco Esteban, Luis Domingo; Ruiz Ramírez, Marc; Comellas Colomé, Jaume; Junyent Giralt, Gabriel no Optical networks, Resource differentiation, Shared path protection 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. This analysis concludes that, with current resource assignment policies, only a very poor grade of service can be provided to the carried best effort traffic. Hence, we propose diff-WS, a resource partitioning scheme that differentiates those wavelengths supporting each class of service in the network. The benefits of diff-WS in front of current resource assignment policies are afterwards evaluated from an economic perspective. To this goal, we define the NORMA problem as a revenue maximization problem. To solve NORMA, we introduce statistical models to obtain, for a given grade of service, the highest traffic intensity for each supported class of service and resource assignment scheme. From the numerical results, we show that diff-WS maximizes resource utilization in the network and, thus, network operator’s profit. http://hdl.handle.net/2117/16854 Title: A novel monitor placement algorithm for accurate performance monitoring in optical networks Authors: Angelou, Marianna; Pointurier, Yvan; Azodolmolky, Siamak; Careglio, Davide; Spadaro, Salvatore; Tomkos, Ioannis Abstract: 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 methods. Wed, 07 Nov 2012 11:01:24 GMT http://hdl.handle.net/2117/16854 2012-11-07T11:01:24Z Angelou, Marianna; Pointurier, Yvan; Azodolmolky, Siamak; Careglio, Davide; Spadaro, Salvatore; Tomkos, Ioannis no Monitoring, QoS, QoT, Quality of service, Quality of transmission 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 methods. http://hdl.handle.net/2117/16498 Title: Physical layer evaluation of OFDM-based access networks Authors: Cano Valadez, Ivan; Santos Blanco, M. Concepción; Prat Gomà, Josep Joan; Krimmel, H.G.; Kavatzikidis, T.; Giacoumidis, E.; Tomkos, Ioannis Abstract: In this paper, we present a physical layer parameter optimization of direct-detection optical OFDM techniques at bitrates of 10 Gb/s and 40 Gb/s using an intensity modulation and two types of field modulation transmitters: optical IQ modulator and frequency up-conversion. The performance of these schemes is evaluated and compared for access networks. Fri, 14 Sep 2012 11:35:58 GMT http://hdl.handle.net/2117/16498 2012-09-14T11:35:58Z Cano Valadez, Ivan; Santos Blanco, M. Concepción; Prat Gomà, Josep Joan; Krimmel, H.G.; Kavatzikidis, T.; Giacoumidis, E.; Tomkos, Ioannis no In this paper, we present a physical layer parameter optimization of direct-detection optical OFDM techniques at bitrates of 10 Gb/s and 40 Gb/s using an intensity modulation and two types of field modulation transmitters: optical IQ modulator and frequency up-conversion. The performance of these schemes is evaluated and compared for access networks.