http://hdl.handle.net/2117/1934 2013-05-20T07:45:12Z http://hdl.handle.net/2117/19285 Title: Parallelization of the interpolation process in the Koetter-Vardy soft-decision list decoding algorithm Authors: Moreira Sánchez, José; Fernández Muñoz, Marcel; Soriano Ibáñez, Miguel Abstract: List decoding is a decoding strategy that provides a set of codewords at the output of the channel decoder. Since this technique corrects errors beyond the correcting bound of the code, upper layers in the application or in the communications protocol can choose the appropriate candidate codeword among the elements of the set. The Koetter-Vardy algorithm is a soft-decision decoding algorithm for Reed-Solomon codes. It is based on two sequential processes: interpolation and factorization. In most applications it is interesting to efficiently decode in real time. This paper discusses some parallelization results about the interpolation process, which is the highest time-consuming part of the Koetter-Vardy algorithm. 2013-05-16T10:33:32Z http://hdl.handle.net/2117/18818 Title: Formación curricular de diseño para todos en informática y telecomunicaciones Authors: Abascal, Julio; Garay, Nestor; Guasch Murillo, Daniel 2013-04-16T13:25:28Z http://hdl.handle.net/2117/18557 Title: Adding QoS support for timeliness to the observe extension of CoAP Authors: Ludovici, Alessandro; García, Ernesto; Gimeno, Xavier; Calveras Augé, Anna M. Abstract: In this paper, we propose a modification of the observe extension of CoAP to include Quality of Service (QoS) support for timeliness. The proposed QoS support is based on delivery priority. Nodes are able to express the priority order with which they wish to be notified. Furthermore, they are also able to specify which notification they want to receive. We classify the notifications in two categories: Critical and Non-Critical. The provided QoS is the result of a negotiation between the client and server. The client demands a certain degree of QoS according to its role. The server could accept or negotiate it. This choice depends on the availability of server and network resources. We evaluate our proposal in a real Wireless Sensor Network. An e-health application has been chosen as target of our tests. The performance evaluation is done in terms of average delay, energy consumption and delivery ratio. 2013-04-03T10:08:30Z http://hdl.handle.net/2117/18556 Title: Presence-based architecture for wireless sensor networks using publish/subscribe paradigm Authors: Calveras Augé, Anna M.; Garcia Davis, Ernesto Abstract: Ubiquitous communication is a key component of Ambient Intelligence, enabling objects to communicate with each-other by means of a wireless ad-hoc network. A presence service allows knowing the availability or responsiveness status of elements in a communication (entities). Traditionally, only human use this service, however all smart devices or objects (with embedded wireless sensor nodes) could interact with each other thus a presence service could also enhance communication among them. To achieve this objective we look into existing protocols to propose the requirements needed to provide presence service on Wireless Sensor Networks (WSN). The main contribution of this paper is the discussion of requirements for presence services on WSN and the new proposed architecture to cope with presence services in WSN. 2013-04-03T09:50:03Z http://hdl.handle.net/2117/18528 Title: RAR: Un mecanismo "Risk-Aware" para redes vehiculares Authors: Hernández Gañán, Carlos; Muñoz Tapia, José Luis; Hinarejos Campos, M. Francisca; Isern Deyà, Andreu; Alins Delgado, Juan José Abstract: Las redes vehiculares requieren de alg ́ un meca- nismo para autenticar los mensajes, identificar a los veh ́ ıculos leg ́ ıtimos y sacar de la red aqu ́ ellos que no presenten un comportamiento adecuado. La infrastructura de clave p ́ ublica (PKI) puede proporcionar estos requisitos mediante el uso de certificados digitales. Sin embargo, la adopci ́ on de una PKI, conlleva la necesidad de gestionar no tan s ́ olo la emisi ́ on de certificados sino tambi ́ en su revocaci ́ on. El est ́ andar IEEE 1609.2 apunta que la revocaci ́ on de certificados en redes vehiculares debe depender del uso de Listas de Certificados Revocados (CRLs). En este art ́ ıculo, analizamos los problemas derivados del uso de CRLs en este tipo de redes. Asimismo, proponemos un mecanismo para gestionar el riesgo inherente del uso de estas listas el cual mejora el uso tradicional de las CRLs. Ayud ́ andose del canal de control de este tipo de redes, nuestro mecanismo es capaz de dar a conocer la frescura de los datos de revocaci ́ on en tiempo real. Adem ́ as, este mecanismo permite a los usuarios estimar el riesgo operacional que asumen al usar las CRLs. 2013-04-02T10:29:44Z http://hdl.handle.net/2117/18495 Title: Study of the results in a heterogenous group for a course on computer networks Authors: Barceló Arroyo, Francisco; Martín Escalona, Israel Abstract: This paper shows statistics of a group at the Faculty of Telecommunications Engineering in Barcelona (Spain). Due to the different origin and academic background of the students, planning the course is a challenging task. This work shows the features that characterize the group as heterogeneous. Statistics about the origin and the grades of a test before the course are shown along with the existing correlation between both. The paper also analyzes the grades obtained in the final exams and relates them to the origin and initial test. In the statistics some groups can be differentiated with students belonging to each group showing a similar degree of academic progress. The results allow drawing some conclusions on how a careful observation of the countries of origin, academic background and the results of a test before starting the course can help to plan a balanced course and evaluation. 2013-03-22T12:57:41Z 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/2117/18484 Title: RAR: Risk aware revocation mechanism for vehicular networks Authors: Hernández Gañán, Carlos; Muñoz Tapia, José Luis; Esparza Martín, Óscar; Mata Diaz, Jorge; Alins Delgado, Juan José; Silva Cárdenas, Carlos; Bartra Gardini, Gumercindo Abstract: Vehicular Ad Hoc Networks (VANETs) require some mechanism to authenticate messages, identify valid vehicles, and remove misbehaving ones. A Public Key Infrastructure (PKI) can provide this functionality using digital certificates. In PKI, key management and corresponding issuance and revocation of digital certificates is one of the key issues that have to be solved. The IEEE 1609.2 standard states that VANETs will rely on the use of certificate revocation lists (CRLs) to achieve revocation. In this paper, we analyze the problems of using CRLs in these type of networks. Moreover, we describe the Risk Aware Revocation (RAR) mechanism that improves the traditional use of CRLs. RAR takes advantage of the two distinct channel types in VANETs to increase the freshness of the revocation information. Moreover, RAR allows users to gauge the risk of operating in a VANET when using CRLs. 2013-03-22T11:52:09Z http://hdl.handle.net/2117/18380 Title: Guía de responsabilidad social universitaria y discapacidad: RSU-D Authors: Guasch Murillo, Daniel; Àlvarez Suau, Maria Hortènsia; Dotras Ruscalleda, Pilar; Vállez Vidal, Raquel; Guasch Murillo, Yolanda 2013-03-19T08:01:23Z http://hdl.handle.net/2117/18332 Title: Implementation of context-aware network architecture for smart objects based on functional composition Authors: Ferrer Riera, José Luis; Sánchez Loro, Xavier; Calveras Augé, Anna M.; Paradells Aspas, Josep Abstract: Lack of flexibility of current Internet architecture led researchers to come up with new paradigms for a novel Internet architecture, which would be able to reduce complexity and increase flexibility compared to current Internet architecture. Functional co mposition is a promising approach to flexible and evolvable architecture design. The idea is composing complex protocol suites by dynamically bind and arrange different functions to obtain certain behavior. Herein, we present the implementation of a contex t - aware network architecture based on functional composition for smart objects. A sub - set of those basic functional blocks has been implemented and validated on an experimental testbed using different network topologies . 2013-03-15T09:39:46Z http://hdl.handle.net/2117/18155 Title: Entornos adaptados para personas con discapacidad mental Authors: Guasch Murillo, Daniel; Bonasa Jiménez, Mª del Pilar; López Novella, Judit; Mayor Sánchez, Carolin; Guasch Murillo, Yolanda Abstract: Las universidades tienen ante sí un reto importante en conseguir entornos accesibles para el alumnado con discapacidad mental donde puedan desarrollar con éxito sus estudios universitarios y, de esta forma, mejorar sus perspectivas laborales. Sólo el 5,4% de las personas con discapacidad de 25 o más años tienen estudios universitarios o equivalentes, siendo este porcentaje del 18,7% en el caso de las personas sin discapacidad (Observatorio Estatal de la Discapacidad, 2010). Si se observa el porcentaje de estudiantes con discapacidad mental frente al resto de discapacidades, según el avance de resultados del censo de alumnos universitarios con discapacidad del curso académico 2011-2012 del Observatorio Estatal de la Discapacidad, el 1,24% son estudiantes con discapacidades intelectuales, el 3,83% padecen trastornos mentales, el 0,58% padecen trastornos generalizados del desarrollo, el 5,95% padecen trastornos psicológicos y el 0,76% padecen trastornos del aprendizaje. Mientras que el número de estudiantes con discapacidad física asciende a un 34,38%, el de estudiantes con discapacidades orgánicas a 10,90%, los que poseen discapacidades visuales 8,59% y los que tienen una discapacidad auditiva son un 6,71%. Si se engloban las discapacidades mentales, el porcentaje de estudiantes con este tipo de discapacidad resulta en un 13,36% constituyéndose como el segundo grupo después de las discapacidades físicas. 2013-03-08T19:12:05Z http://hdl.handle.net/2117/18154 Title: Guía para implementar el Universal Instructional Design (diseño Instruccional Universal) en la Universidad Authors: Guasch Murillo, Daniel; Dotras Ruscalleda, Pilar; Àlvarez Suau, Maria Hortènsia; Guasch Murillo, Yolanda Abstract: esta guía se centrará en establecer cuáles son las pautas para implementar o poner en práctica el Universal Instructional Design-UID (diseño instruccional universal) en la enseñanza universitaria a partir del análisis del modelo de la University of Guelph (Canadá). Los objetivos específicos que se persiguen son: Delimitar el concepto teórico del UID, justificar la implementación en la Universidad del UID, analizar la implementación del UID en la University of Guelph, establecer las pautas para favorecer la implementación o puesta en práctica del UID en las universidades españolas. 2013-03-08T19:00:45Z http://hdl.handle.net/2117/18153 Title: COACH: COllaborative certificate stAtus CHecking mechanism for VANETs Authors: Hernández Gañán, Carlos; Muñoz Tapia, José Luis; Esparza Martín, Óscar; Mata Diaz, Jorge; Hernández Serrano, Juan; Alins Delgado, Juan José Abstract: Vehicular Ad Hoc Networks (VANETs) require mechanisms to authenticate messages, identify valid vehicles, and remove misbehaving vehicles. A public key infrastructure (PKI) can be used to provide these functionalities using digital certificates. However, if a vehicle is no longer trusted, its certificates have to be revoked and this status information has to be made available to other vehicles as soon as possible. In this paper, we propose a collaborative certificate status checking mechanism called COACH to efficiently distribute certificate revocation information in VANETs. In COACH, we embed a hash tree in each standard Certificate Revocation List (CRL). This dual structure is called extended-CRL. A node possessing an extended-CRL can respond to certificate status requests without having to send the complete CRL. Instead, the node can send a short response (less than 1 kB) that fits in a single UDP message. Obviously, the substructures included in the short responses are authenticated. This means that any node possessing an extended-CRL can produce short responses that can be authenticated (including Road Side Units or intermediate vehicles). We also propose an extension to the COACH mechanism called EvCOACH that is more efficient than COACH in scenarios with relatively low revocation rates per CRL validity period. To build EvCOACH, we embed an additional hash chain in the extended-CRL. Finally, by conducting a detailed performance evaluation, COACH and EvCOACH are proved to be reliable, efficient, and scalable. 2013-03-08T18:53:14Z http://hdl.handle.net/2117/18151 Title: La responsabilidad social universitaria y discapacidad (RSU-D) Authors: Guasch Murillo, Daniel; Dotras Ruscalleda, Pilar; Berbegal Mirabent, Jasmina; Villalta Boix, Marta; Àlvarez Suau, Maria Hortènsia; Guasch Murillo, Yolanda Abstract: Si buscásemos una definición académica de universidad encontraríamos conceptos como institución de enseñanza superior; conjunto de facultades y escuelas; o responsabilidad de generar, almacenar y diseminar el conocimiento. Pero estas definiciones solo toman pleno significado en el marco de una sociedad avanzada donde la universidad es una parte viva y activa dentro de la comunidad. Consecuentemente no puede permanecer aliena a la realidad que la rodea. Debe velar por garantizar la mejor prestación de servicio posible y retornar a la sociedad el resultado de su trabajo, estableciéndose una simbiosis natural. Desde el Observatorio Universidad y Discapacidad se proponen a continuación un conjunto de reflexiones para la comunidad universitaria con el fin de velar por la igualdad de oportunidades de todos los colectivos que la conforman; pudiéndose garantizar ese retorno, inmaterial y responsable, a todos los colectivos de la sociedad a la que pertenece. 2013-03-08T18:34:22Z 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