http://hdl.handle.net/2117/2437 2013-05-24T22:14:51Z http://hdl.handle.net/2117/18486 Title: Design and analysis of a framework to enhance optical network utilization resources by means of virtualization Authors: Hesselbach Serra, Xavier; Naumenko, Nikolay Abstract: The time for an all-optical network is already here. The huge capacity of the optical resources, in backbones, distribution and access networks cannot be completely used by current services. The remainders can be used under the deployment of new models for service provisio ning. Network virtualizati on is considered as a serious candidate to enable the flexibl e provision of services in the future Internet. This paper introduces a framework to enhance network virtualization allocati on in optical networks. To increase resources utilization efficiency, a new layer above virtualized elements is introduced to map the demands over the resour ces and infrastructures. For that layer, a strategy based on a resource squa tting model is presented, modeled and analyzed. 2013-03-22T12:01:26Z http://hdl.handle.net/2117/18100 Title: Enabling SCI-FI: service-oriented context-aware and intelligent future Internet Authors: González Cela, Alberto José; Germán Duarte, Martín; Alcober Segura, Jesús Ángel; Martin de Pozuelo, Ramon; Pinyol, Francesc; Ghafoor, Kayhan Zrar Abstract: Internet is becoming a huge heterogeneous and dynamic network that is growing beyond its architectural limits. The scaling up of the number of communicating nodes and services is leading the Internet to an architectural crisis which in turn makes it difficult to provide services efficiently considering the requirements and context conditions of users. The Information-Centric Networking (ICN) approach proposes a network where the main paradigm is not an end-to-end communication between hosts, as in the current Internet. Instead, an increasing demand for efficient distribution of content has motivated the development of architectures that focus on information objects. ICN supports the proliferation of services and contents allowing seamless access to them. This work proposes a context-aware service negotiation protocol which will enable to find and compose services whilst meeting requesters’ requirements and, consequently, maximizing the QoE of users. We also provide the main details of a first implementation of the proposed service-oriented solution (SCI-FI) and discuss the gathered results. 2013-03-06T13:15:09Z http://hdl.handle.net/2117/18096 Title: ATENEA UPC and the new "Activity Stream" or "Wall" feature Authors: Alcober Segura, Jesús Ángel; Sanchez, Oriol; Otero, Javier; Marti, Ramon Abstract: The Universitat Politècnica de Catalunya–Barcelona Tech (UPC), has added a new feature to its ATENEA UPC e-Learning platform based on Moodle. ATENEA UPC Service is UPC’s e-Learning platform which supports the Bachelor and Master studies, both face-to-face and blended. This new feature, called "Activity Stream" or "wall", allows progress in the implementation of methodologies based on social learning and mobile learning within the field of university studies. The Institut de Ciències de la Educació (Education Sciences Institute - ICE) leads the educational aims of the platform, and UPCnet -UPC’s ICT services company- offers the service and carries out the technical evolution projects of the platform (change of versions, development of new features, ...) The ICE, teachers at UPC and UPCnet, through working groups and projects in ATENEA Teaching Innovation LABs, evolve and test the new features of the platform that will later incorporate to UPC’s ATENEA Service. The aim of this presentation is to explain the pedagogical motivation of the initiative, the feature’s design process, the technological development done and the result of the actual experience carried out between February and June 2012 within the framework of the official engineering studies taught at the Escola d'Enginyeria de Telecomunicació i Aeronàutica in Castelldefels (EETAC). 2013-03-06T12:08:18Z http://hdl.handle.net/2117/17541 Title: On extending ESnet's OSCARS with a multi-domain anycast service Authors: Boddie, Mark; Entel, Timothy; Guok, Chin; Lake, Andrew; Plante, Jeremy; Pouyoul, Eric; Ramaprasad, Bharath H.; Tierney, Brian; Triay Marquès, Joan; Vokkarane, Vinod M. Abstract: Current scientific data applications require advanced network provisioning systems to support the transport of large volumes of data. Due to the availability of diverse computing and Grid clusters, these applications can benefit from anycasting capabilities. In contrast to unicasting, anycast routing allows the selection of a node from a group of candidate destinations. This new means of communication allows for greater routing flexibility and better network resource consumption. However, current provisioning systems do not provide fully compliant anycast implementations. In this paper, we extend ESnet’s OSCARS virtual circuit provisioning system with anycast routing capabilities to support destination-agnostic applications on single- and multi-domain network scenarios. The proposed implementation significantly improves provisioning success over the native unicast implementation in compliance with the existing OSCARS framework. 2013-01-31T12:36:54Z http://hdl.handle.net/2117/16849 Title: Evaluación de la implementación de los principios de igualdad de oportunidades y accesibilidad universal en los planes de estudio de los títulos de grado de las universidades españolas Authors: Guasch Murillo, Daniel; Dotras Ruscalleda, Pilar; Àlvarez Suau, Maria Hortènsia; Guasch Murillo, Yolanda Abstract: Se presentan los resultados del estudio realizado por el Observatorio Universidad y Discapacidad para determinar el grado de implementación del principio de igualdad de oportunidades por razón de discapacidad y de accesibilidad universal en los planes de estudio de las titulaciones de grado de las universidades públicas españolas y se formulan propuestas que permitan verificar, en mayor medida, la aplicación de dichos principios. 2012-11-07T08:29:47Z http://hdl.handle.net/2117/16217 Title: Comparacion de algoritmos para el mapeo de redes virtuales Authors: Botero Vega, Juan Felipe; Hesselbach Serra, Xavier Abstract: La virtualizacion de red es reconocida como una de las principales tecnologías que formara parte del Internet del futuro. Mediante ella, la actual inhabilidad de Internet para desarrollar e implementar nuevos servicios, causada por la falta de coordinacion entre los proveedores de servicio, podrá ser superada. Aplicar virtualización a los recursos de red nos lleva al problema de asignacion de recursos consistente en asignar (mapear) de manera optima los recursos de la red física a los nodos y enlaces de las redes virtuales, comunmente este problema se ha denominado “problema de incrustar o mapear redes virtuales”. En este artículo se muestran las principales estrategias que han sido propuestas para resolver de manera optima este problema y se comparan teniendo en cuenta varias metricas. 2012-07-09T16:26:20Z http://hdl.handle.net/2117/16216 Title: A squatting based framework to enhance network virtualization allocation in optical networks Authors: Hesselbach Serra, Xavier; Naumenko, Nikolay Abstract: This paper introduces a framework to enhance network virtualization allocation in optical networks. A new control plane approach for the new generation of electrical and optical networks technologies is presented. To increase resources utilization efficiency, a new layer above virtualized elements is introduced in order to take into account the demands in order to control the resources and infrastructures below. For that layer, a strategy based on a resource squatting model is presented. 2012-07-09T16:23:08Z http://hdl.handle.net/2117/16215 Title: VNREAL: Virtual network resource embedding algorithms in the framework ALEVIN Authors: Duelli, Michael; Schlosser, Daniel; Botero Vega, Juan Felipe; Hesselbach Serra, Xavier; Fischer, A.; de Meer, Hermann Abstract: Network virtualization is recognized as an enabling technology for the Future Internet that overcomes network ossification. However, it introduces a set of challenges. In any network virtualization environment, the problem of optimally mapping virtual resources to physical resources, known as virtual network embedding (VNE), is a critical challenge. Several algorithms attempting to solve this problem have been proposed in literature, so far. However, comparison of existing and new VNE algorithms is hard, as each algorithm focuses on different criteria. To that end, the VNREAL project introduces ALEVIN, a framework to compare different algorithms according to a set of metrics, easily incorporate new VNE algorithms, and evaluate these algorithms on a given scenario for arbitrary parameters. 2012-07-09T16:17:40Z http://hdl.handle.net/2117/16050 Title: Adjust of solar cell model parameters based in MATLAB Authors: Silvestre Bergés, Santiago; Guasch Murillo, Daniel; Ortega Villasclaras, Pablo Rafael; Navarro Mas, Nacho Abstract: In this work, a model parameter extractor of solar cells using Matlab is shown. The software, developed in Matlab environment, has been successfully applied to study internal characteristics of photovoltaic devices [1-2], as well as on-line photovoltaic system performance [3-4]. However, in this case, the developed tool allows to obtain automatically electrical parameters than are often requested to model the performance of single solar cells, as can be the photocurrent density Jph, series resistance Rs, shunt resistance Rsh, saturation current Io, and ideality factor n. Parameters of a second diode, that takes into account recombination losses, as can be the saturation current Iorec and ideality factor nrec, are also included . Special attention has been focused on the extimation of the series resistance Rs, and the evolution of this parameter in dark and illumination work conditions of the solar cell. 2012-06-14T16:48:37Z http://hdl.handle.net/2117/15634 Title: Real-time services in EPON Authors: Garfias Hernandez, Paola; Sallent Ribes, Sebastián; Gutiérrez González, Lluís; Camps Mur, Daniel Abstract: This paper proposes an improved scheduling algorithm that optimizes the allocation of the real-time services and elastic flows in EPON by spreading the real-time service periods lowering the delay and thus fulfilling the QoS requirements. 2012-03-21T12:02:50Z http://hdl.handle.net/2117/15564 Title: Designing Messenger Visual, an instant messaging service for individuals with cognitive disability Authors: Tuset, Pere; López, Juan Miguel; Barberán, Pere; Janer, Léonard; Cervelló Pastor, Cristina Abstract: Considering the importance of Internet-based communications in our society, the lack of Instant Messaging (IM) services adapted to individuals with cognitive disabilities who have difficulties using written language creates a situation of exclusion that has a negative impact on their daily lives. To alleviate this situation we present Messenger Visual, an IM service that uses pictograms as the main communication system. Along the paper we introduce the main design aspects of an IM service to support pictogram-based communications, as well as the design and evaluation aspects of an IM client that takes into account both the pictogram-based communication and the user interface accessibility requirements of individuals with cognitive disabilities. 2012-03-13T16:13:36Z http://hdl.handle.net/2117/15173 Title: Flexible VNE algorithms analysis using ALEVIN Authors: Botero Vega, Juan Felipe; Hesselbach Serra, Xavier; Duelli, Michael; Schlosser, Daniel; Fischer, A.; de Meer, Hermann Abstract: Network virtualization is recognized as an enabling technology for the Future Internet that overcomes network ossification. However, it introduces a set of challenges. In any network virtualization environment, the problem of optimally mapping virtual demands to physical resources, known as virtual network embedding (VNE), is a crucial challenge. This paper analyses the behaviour of the main algorithms proposed to solve VNE by means of the ALEVIN framework. The VNE algorithms are evaluated with regard to appropriate metrics such as: cost, revenue, and virtual network acceptance ratio. We also analyse the impact of the recently introduced hidden hop demand concept in the performance of the VNE algorithms. 2012-02-15T16:20:14Z http://hdl.handle.net/2117/15170 Title: ALEVIN - A framework to develop, compare, and analyze virtual network embedding algorithms Authors: Fischer, Andreas; Botero Vega, Juan Felipe; Duelli, Michael; Schlosser, Daniel; Hesselbach Serra, Xavier; de Meer, Hermann Abstract: Network virtualization is recognized as an enabling technology for the Future Internet. Applying virtualization of network resources leads to the problem of mapping virtual resources to physical resources, known as “Virtual Network Embedding” (VNE). Several algorithms attempting to solve this problem have been discussed in the literature, so far. However, comparison of VNE algorithms is hard, as each algorithm focuses on different criteria. To that end, we introduce a framework to compare different algorithms according to a set of metrics, which allow to evaluate the algorithms and compute their results on a given scenario for arbitrary parameters. 2012-02-15T15:28:07Z http://hdl.handle.net/2117/15168 Title: Bundles fragmentation in vehicular delay-tolerant networks Authors: Magaia, N; Pereira, P. R.; Casaca, A.; Rodrigues, J.J.P.C.; Dias, J. A.; Isento, J. N.; Cervelló Pastor, Cristina; Gallego Ezpeleta, J. Abstract: Vehicular Delay-Tolerant Networks use the delaytolerant architecture and protocols to overcome the disruptions in network connectivity. These concepts help in cases where the network is sparse or with large variations in density or there is no end-to-end connectivity, by providing a communications solution for non real-time applications. This paper presents data fragmentation techniques to optimize the efficiency of data delivery for the case of the short node contacts that characterize vehicle networks. The techniques were tested in a laboratory environment with portable digital assistants and Lego Mindstorm NXT robotic cars. If no fragmentation is used, only small messages are successfully transferred. Proactive fragmentation fragments messages to a predefined size in the source node. Reactive fragmentation adjusts the fragment sizes to the real duration of the contact when it is broken. Reactive fragmentation showed a good efficiency in adapting the fragmentation in real time to the contact duration. Proactive fragmentation can perform slightly better if the fragment sizes are carefully chosen as it requires less processing. As this choice is difficult, reactive fragmentation is more practical to use. 2012-02-15T14:57:23Z http://hdl.handle.net/2117/14680 Title: Flexible joint scheduling DBA to promote the fair coexistence in 1G and 10G EPONs Authors: Gutiérrez González, Lluís; Garfias Hernandez, Paola; Sallent Ribes, Sebastián Abstract: The Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. The real challenge faced by 10GEPON new standard IEEE 803.3av is to upgrade the channel capacity for both upstream and downstream channels gracefully, while maintaining the logical layer intact ensuring the coexistence with legacy 1 Gb/s (IEEE 802.3ah). The Dynamic Bandwidth Allocation (DBA) for the upstream shared channel is a key issue. We propose in this paper a distributed DBA-Distributed Dynamic Scheduling for EPON, (DDSPON)-that allows the coexistence among both standards in such mixed architecture. In particular, we remark that, by using the enhanced DDSPON, the new standardized optical network units (ONUs) will take full advantage of the enhanced rate at 10 Gb/s while the legacy 1 Gb/s ONUs keep a good performance, and thus allowing a fair coexistence of both groups of ONUs-legacy and 10 Gb/s-, and even though the individual performance is maximized, no matter the group being evaluated. We compare DDSPON with another well-known scheduling algorithm and we show that it performs better specially when the traffic is bursty. Furthermore, the proposed algorithm is scalable, simple to re-configure, and cost-effective, which facilitates a smoother transition from 1G to 10G EPON. 2012-01-19T13:28:18Z