Aggregation and Conformance in Differentiated Service Networks: A Case Study

The Differentiated Service (Diff-Serv) architecture [1] advocates a model based on different “granularity” at network edges and within the network. In particular, core routers are only required to act on a few aggregates that are meant to offer a pre-defined set of service levels. The use of aggregation raises a number of questions for end-to-end services, in particular when crossing domain boundaries where policing actions may be applied. This paper focuses on the impact of such policing actions in the context of individual and bulk services built on top of the Expedited Forwarding (EF) [7] per-hop-behavior (PHB). The findings of this investigation confirm and quantify the expected need for reshaping at network boundaries, and identify a number of somewhat unexpected behaviors. Recommendations are also made for when reshaping is not available

MAC Protocols for Wake-up Radio: Principles, Modeling and Performance Analysis

© 2018 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] In wake-up radio (WuR) enabled wireless sensor networks (WSNs), a node triggers a data communication at any time instant by sending a wake-up call (WuC) in an on-demand manner. Such wake-up operations eliminate idle listening and overhearing burden for energy consumption in duty-cycled WSNs. Although WuR exhibits its superiority for light traffic, it is inefficient to handle high traffic load in a network. This paper makes an effort towards improving the performance of WuR under diverse load conditions with a twofold contribution. We first propose three protocols that support variable traffic loads by enabling respectively clear channel assessment (CCA), backoff plus CCA, and adaptive WuC transmissions. These protocols provide various options for achieving reliable data transmission, low latency, and energy efficiency for ultralow power consumption applications. Then, we develop an analytical framework based on an M/G/1/2 queue to evaluate the performance of these WuR protocols. Discrete-event simulations validate the accuracy of the analytical models.The work of V. Pla was supported by the Spanish Ministry of Economy, Industry and Competitiveness under Grant TIN2013-47272-C2-1-R. Paper no. TII-17-2251. (Corresponding author: Frank Y. Li)Ghose, D.; Li, F.; Pla, V. (2018). MAC Protocols for Wake-up Radio: Principles, Modeling and Performance Analysis. IEEE Transactions on Industrial Informatics. 14(5):2294-2306. https://doi.org/10.1109/TII.2018.2805321S2294230614

Applying ANFIS Model in Decision-making of Vertical Handover between Macrocell and Femtocell Integrated Network

[EN] One of the most challenging tasks in communication networks is to maintain seamless mobility and service continuity during a vertical handover. This paper provides the case of handover decision making between femtocell and macrocell integrated network considering several input parameters, namely SINR, bandwidth and energy consumption. We have simulated and proposed a vertical handover based on adaptive neuro-fuzzy inference system (ANFIS) to achieve a goal of having an intelligent handover and to predict the best destination network. The simulation results show that the approach based on ANFIS leads to a reduction of unnecessary handovers and a minimization of the energy consumption as compared to the existing approaches.Benaatou, W.; Latif, A.; Pla, V. (2019). Applying ANFIS Model in Decision-making of Vertical Handover between Macrocell and Femtocell Integrated Network. Journal of Telecommunication, Electronic and Computer Engineering. 11(1):57-62. http://hdl.handle.net/10251/159152S576211

Vertical Handover Decision Algorithm in Heterogeneous Wireless Networks

[EN] With the recent progress in the area of cellular communication the issue of inter cells handover without dropping an ongoing connection with the base station has arisen. In this paper, the focus is on the performance of vertical handover. Various proposed interconnection architectures for vertical handover in heterogeneous networks were studied. Two different algorithms to make the decision on when and to which network perform a handover were considered. In the first of them the decision is based on the received signal strength (RSS). In the second one a fuzzy logic system that uses RSS, bandwidth, battery power and packet loss as the input parameters is proposed. The simulation results show that the algorithm based on fuzzy logic leads to a reduction of the number of handovers and a minimisation of the power consumption as compared to the first algorithm used here and the existing algorithms.This work was supported by the Spanish Ministry of Economy and Competitiveness through Grants TIN2013-47272-C2-1-R and BES-2011-045551.Benaatou, W.; Latif, A.; Pla, V. (2017). Vertical Handover Decision Algorithm in Heterogeneous Wireless Networks. International Journal of Internet Protocol Technology (Online). 10(4):197-213. https://doi.org/10.1504/IJIPT.2017.08891419721310

Modeling and Performance Analysis of Channel Assembling in Multi-channel Cognitive Radio Networks with Spectrum Adaptation

[EN] To accommodate spectrum access in multichannel cognitive radio networks (CRNs), the channel-assembling technique, which combines several channels together as one channel, has been proposed in many medium access control (MAC) protocols. However, analytical models for CRNs enabled with this technique have not been thoroughly investigated. In this paper, two representative channel-assembling strategies that consider spectrum adaptation and heterogeneous traffic are proposed, and the performance of these strategies is evaluated based on the proposed continuous-time Markov chain (CTMC) models. Moreover, approximations of these models in the quasistationary regime are analyzed, and closed-form capacity expressions are derived in different conditions. The performance of different strategies, including the strategy without assembling, is compared with one another based on the numerical results obtained from these models and validated by extensive simulations. Furthermore, simulation studies are also performed for other types of traffic distributions to evaluate the validity and the preciseness of the mathematical models. Through both analyses and simulations, we demonstrate that channel assembling represented by the investigated strategies can improve the system performance if a proper strategy is selected with appropriate system parameter configurations.This work was supported in part by the European Union Seventh Framework Programme Marie Curie Actions International Research Staff Exchange Scheme (EU FP7-PEOPLE-IRSES) through the Security, Services, Networking, and Performance of Next Generation IP-Based Multimedia Wireless Networks (S2EuNet) Project under Agreement 247083 and by the Spanish Government through Project TIN2010-21378-C02-02. The review of this paper was coordinated by Prof. Y. Ma.Jiao, L.; Li, FY.; Pla, V. (2012). Modeling and Performance Analysis of Channel Assembling in Multi-channel Cognitive Radio Networks with Spectrum Adaptation. IEEE Transactions on Vehicular Technology. 61:2686-2697. https://doi.org/10.1109/TVT.2012.2196300S268626976

Contribución a la gestión de recursos en redes de acceso celulares. Modelos analíticos y evaluación de prestaciones

Desde sus inicios hace algo más de veinte años, la telefonía móvil celular ha experimentado un enorme crecimiento e importantes transformaciones y, todavía hoy, se encuentra en una fase de cambio y crecimiento. A diferencia de lo que ocurre en una red fija, en la que la enorme capacidad de transmisión que aporta la fibra óptica relega a un segundo plano la gestión eficiente de esta capacidad, el medio de transmisión en la interfaz radio de las redes móviles es un bien escaso. Aunque los avances tecnológicos permiten ampliar el rango de frecuencias utilizables y conseguir una mayor eficiencia espectral, el aumento del tráfico junto a la aparición de nuevos usos y servicios hacen que la gestión eficiente de los recursos radio continúe siendo de gran importancia. El control de admisión (CA) es un mecanismo importante para la gestión de los recursos radio. Aunque el estudio de las técnicas de CA recibió un impulso importante en el contexto de la red digital de servicios Integrados de banda ancha (RDSI-BA), las redes móviles tienen ciertas características específicas que hacen que el CA sea más complejo: las ya referidas limitaciones del espectro, las características propias del canal radio que resultan en un comportamiento aleatorio y, sobre todo, la movilidad de los terminales. En este trabajo se estudia el CA en relación con la movilidad: para admitir una nueva sesión se deben tener ciertas garantías -al menos en un sentido estadístico- de que la red tendrá recursos suficientes para mantener, con la calidad de servicio (QoS) requerida, tanto esa nueva sesión como las ya existentes en ese momento, y ello teniendo en cuenta que durante la vida de una sesión, ésta -el terminal- puede cambiar de área de cobertura (célula), y los recursos deberán estar disponibles allí donde vaya el terminal. Aunque el interés por este tema no es nuevo, continúa vigente, pues para atender la creciente demanda de capacidad, una de las formas pasa por reducir el tamaño de las células....Pla Boscà, V. (2005). Contribución a la gestión de recursos en redes de acceso celulares. Modelos analíticos y evaluación de prestaciones [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/2001Palanci

Candidate Selection Algorithms in Opportunistic Routing based on Distance Progress

Opportunistic Routing (OR) is a new class of routing protocols that selects the next-hop forwarder on-the-fly. In contrast to traditionally routing, OR does not select a single node as the next-hop forwarder, but a set of forwarder candidates. When a packet is transmitted, the candidates coordinate such that the best one receiving the packet will forward it, while the others will discard the packet. The selection and prioritization of candidates, referred to as candidate selection algorithm, has a great impact on OR performance. In this paper we propose and study two new candidate selection algorithms based on the geographic position of nodes. This information is used by the candidate selection algorithms in order to maximize the distance progress towards the destination. We compare our proposals with other well-known candidate selection algorithms proposed in the literature through mathematical analysis and simulation. We show that candidate selection algorithms based on distance progress achieve almost the same performance as the optimum algorithms proposed in the literature, while the computational cost is dramatically reduced.Darehshoorzadeh, A.; Cerdà-Alabern, L.; Pla, V. (2015). Candidate Selection Algorithms in Opportunistic Routing based on Distance Progress. International Journal of Ad Hoc and Ubiquitous Computing. 20(3):137-147. doi:10.1504/IJAHUC.2015.073168S13714720

"Frozen Out", videojuego de aventura gráfica 3D. Diseño y uso de los diálogos

[ES] Esta memoria trata el desarrollo de un proyecto de emprendimiento, un videojuego de aventuras y puzles en tres dimensiones, dentro del marco de la universidad, así como la implementación de los sistemas de juego que posibilitaron las funcionalidades del diálogo. El producto se realizó dentro de un equipo multidisciplinar de cinco estudiantes y utilizando el motor de videojuegos Unity. La propuesta original se analizó y se desarrollaron un conjunto de características para evaluar su viabilidad en dos experimentos frente a público objetivo, los cuales resultaron tener una recepción positiva. Por otro lado, en cuanto al apartado técnico se indagaron e integraron herramientas existentes centradas en el control de conversaciones y se implementación extensiones a este para acomodarse a las necesidades del proyecto en cuestión, resultando en la creación de un gestor de diálogos flexible y personalizable para otros proyectos.[EN] This paper is about the development of an entrepreneur project, a 3D adventure videogame with puzzles, inside the framework of the university. It will also dive into the implementation of the game systems related to the dialogue functionalities. The project was conducted inside a multidisciplinary team of five students and Unity was used as the game engine. The original proposal was therefore analysed, and a set of characteristics was picked to be developed and carry out two experiments aimed at the public, where the project received positive feedback. In regard to the technical aspects, a variety of tools designed to control conversations were researched and they were integrated and extended to adjust them to our videogame¿s need, which resulted in the creation of a flexible dialogue manager that could be personalised for other projects.[CA] Aquesta memòria tracta el desenvolupament d’un projecte d’emprenedoria, un videojoc d’aventures i puzles en tres dimensions, dins del marc de la universitat, així com la implementació dels sistemes de joc que possibiliten les funcions del diàleg. El projecte es va realitzar dins d’un equip multidisciplinar de cinc estudiants i utilitzant el motor de videojocs Unity. La proposta original es va analitzar i es varen desenvolupar un conjunt de característiques per a avaluar la seua viabilitat amb dos experiments orientats al públic objectiu, els quals van rebre una recepció positiva. En quant a l’apartat tècnic, es varen indagar e integrar ferramentes existents centrades en el control de conversacions y es varen implementar extensions a aquest per a acomodar-se a les necessitats del videojoc, resultant en un gestor de diàlegs flexible i personalitzable per a altres projectes.Pla Madrid, V. (2020). "Frozen Out", videojuego de aventura gráfica 3D. Diseño y uso de los diálogos. http://hdl.handle.net/10251/150974TFG

Dynamic Spectrum Reservation for CR Networks in the Presence of Channel Failures: Channel Allocation and Reliability Analysis

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] Providing channel access opportunities for new service requests and guaranteeing continuous connections for ongoing flows until service completion are two challenges for service provisioning in wireless networks. Channel failures, which are typically caused by hardware and software failures or/and by intrinsic instability in radio transmissions, can easily result in network performance degradation. In cognitive radio networks (CRNs), secondary transmissions are inherently vulnerable to connection breaks due to licensed users' arrivals as well as channel failures. To explore the advantages of channel reservation on performance improvement in error-prone channels, we propose and analyze a dynamic channel reservation (DCR) algorithm and a dynamic spectrum access (DSA) scheme with three access privilege variations. The key idea of the DCR algorithm is to reserve a dynamically adjustable number of channels for the interrupted services to maintain service retainability for ongoing users or to enhance channel availability for new users. Furthermore, the DCR algorithm is embedded in the DSA scheme enabling spectrum access of primary and secondary users with different access privileges based on access flexibility for licensed shared access. The performance of such a CRN in the presence of homogeneous and heterogeneous channel failures is investigated considering different channel failure and repair rates.The work of V. Pla was supported by the Spanish Ministry of Economy, Industry and Competitiveness under Grant TIN2013-47272-C2-1-R.Balapuwaduge, IAM.; Li, F.; Pla, V. (2018). Dynamic Spectrum Reservation for CR Networks in the Presence of Channel Failures: Channel Allocation and Reliability Analysis. IEEE Transactions on Wireless Communications. 17(2):882-898. https://doi.org/10.1109/TWC.2017.2772240S88289817