Anàlisi d'eines digitals per obtenir una retroacció ràpida de les competències assolides

Avui dia ningú dubta de la gran utilitat que té l'ús d'eines digitals dins de l'entorn educatiu. Aquest projecte tracta d'avaluar si les eines digitals disponibles per realitzar una avaluació ràpida, són realment útils, o no, i quines són. El projecte es centra en analitzar les "principals" eines digitals que permeten dur a terme una avaluació formativa (Avaluació per l'Aprenentatge) i obtenir una retroacció immediata del nivell assolit pels alumnes. Per a dur a terme aquest anàlisis, és necessari especificar un conjunt de requeriments i mostrar després una taula comparativa on s'indicarà quins dels requeriments establerts compleixen o no les eines. L'objectiu de l'estudi és veure quines eines són aptes per a realitzar una "avaluació improvisada amb retroacció immediata", és a dir, llançar preguntes al vol, per tal de fer-se una idea, en el mateix moment, del nivell de coneixements dels alumnes. Un cop detectades les eines que sí compleixen els requeriments, i un cop realitzada la prova a l'aula, per verificar-ne la seva utilitat, es mostrarà un breu resum de les característiques principals, per passar tot seguit a detallar la seva configuració i ús per aplicar-les a l'aula. El mètode de treball utilitzat ha estat el d'assaig-error, aplicant el cicle de millora de Deming (Plan, Do, Check i Act.) fins passar d'un estat d'incertesa en la definició de variables, fins a tenir clar el nombre i tipus de variables necessàries (un total de nou variables)..

Contribución a la caracterización de los mecanismos de acceso y traspaso en sistemas móviles celulares basados en transmisión de paquetes

La estandarización del esquema de acceso radio para los futuros sistemas de telecomunicación está a punto de ser una realidad. En el calendario propuesto por ITU para llevar a cabo la elaboración del estándar, se prevé que las primeras versiones de las especificaciones técnicas puedan estar disponibles a principios del año 2000. Pero la llegada de la tercera generación, conocida bajo el concepto IMT-2000 dentro de ITU y como UMTS en el ámbito europeo, no estsupeditada únicamente a la incorporación del nuevo sistema de acceso radio, sino que existe una marcada tendencia de migración de los sistemas móviles actuales hacia la provisión de los diferentes servicios y prestaciones ambicionados en el sistema IMT-2000/UMTS.Por tanto, el sistema IMT-2000/UMTS se plantea como una convergencia de diferentes sistemas y nuevas tecnologías que, paulatinamente, van armonizando sus características para poder llegar a conseguir una única plataforma global de telecomunicaciones. Y una de las directrices seguidas en dicha convergencia es la adopción de las denominadas técnicas de transmisión en modo paquete en sustitución de las actuales soluciones basadas en conmutación de circuitos. Algunos de los argumentos esgrimidos a favor de la incorporación de mecanismos de transmisión en modo paquete son los siguientes:* La posibilidad de realizar un uso más eficiente de los recursos radio disponibles. La asignación fija durante el transcurso de toda una conexión puede resultar completamente ineficiente para servicios a ráfagas o con tasas de transmisión fluctuantes.* Mayor flexibilidad a la hora de integrar tráfico de diferente naturaleza, como por ejemplo, voz, datos, deñales de vídeo, etc.* La mayor imbricación de las tecnologías de la información (IT), orientadas a paquetes, en las tecnologías de telecomunicaciones.* La integración paulatina de las redes de acceso móviles a una plataforma

Provisión de banda ancha móvil para seguridad pública y emergencias

El acceso de banda ancha móvil es fundamental para mejorar la eficiencia y efectividad de las comunicaciones de seguridad pública y emergencias. En este artículo se identifican y argumentan los tres pilares básicos sobre los que, en opinión de los autores, debe cimentarse la necesaria evolución de los servicios y sistemas de comunicaciones actuales: (1) adopción y alineamiento con las tecnologías de banda ancha móvil utilizadas en el entorno comercial; (2) explotación de estrategias de compartición de infraestructura y redes con actores comerciales; y (3) incorporación de principios de compartición de espectro.Peer ReviewedPostprint (published version

WLAN throughput improvement via distributed queuing MAC

This paper analyzes the performance of a MAC scheme for wireless local area networks (WLANs) that makes use of distributed queues to improve radio channel utilization. Analytical values for the maximum throughput performance are derived as a function of the system parameters. The obtained results show that the proposed scheme outperforms the legacy 802.11 MAC protocol in terms of maximum stable throughput. This benefit is obtained from eliminating back-off periods and collisions in data packet transmissions while minimizing the needed control overhead. The proposal also makes performance to be independent of the number of nodes transmitting in the system and provides stability for high load conditionsPeer Reviewe

Interworking in heterogeneous wireless networks: comprehensive framework and future trends

Interworking mechanisms are of prime importance to achieve ubiquitous access and seamless mobility in heterogeneous wireless networks. In this article we develop a comprehensive framework to categorize interworking solutions by defining a generic set of interworking levels and its related key interworking mechanisms. The proposed framework is used to analyze some of the most relevant interworking solutions being considered in different standardization bodies. More specifically, I-WLAN and GAN approaches for WLAN and cellular integration, solutions for WiMAX and 3GPP LTE/SAE interworking, and the forthcoming IEEE 802.21 standard are discussed from the common point of view provided by the elaborated framework.Postprint (published version

A channel allocation algorithm for OSA-Enabled IEEE 802.11 WLANs

Channel allocation problem is a major challenge in wireless local area networks (WLANs), especially in dense deployments of access points (APs) where congestion of the unlicensed spectrum bands (i.e., ISM bands) could undermine achieved network performance. This paper analyses the possibility to alleviate congestion of the ISM band by allowing some APs to use additional channels located in licensed bands in an opportunistic manner whenever licensee services (i.e., primary users) are not affected. Availability of these additional channels in licensed bands is assumed not to be the same for all the APs. Based on this assumption, we formulate the problem for the channel assignment as a Binary Linear Programming (BLP) problem, which allows us to obtain an optimal solution despite an elevated execution time. We also develop a heuristic method based on building a Minimum Spanning Tree (MST) graph attending to interference conditions that is able to find nearoptimal solutions with a shorter execution time. Results are provided to assess the benefits of such a proposal under different WLAN deployment situations and primary channel availability conditions.Postprint (published version

On radio access network slicing from a radio resource management perspective

Network slicing is a fundamental capability for future 5G networks to properly support current and envisioned future application scenarios. Network slicing facilitates a cost-effective deployment and operation of multiple logical networks over a common physical network infrastructure such that each network is customized to best serve the needs of specific applications (e.g., mobile broadband, Internet of Things applications) and/or communications service providers (e.g., special purpose service providers for different sectors such as public safety, utilities, smart city, and automobiles). Slicing a RAN becomes particularly challenging due to the inherently shared nature of the radio channel and the potential influence that any transmitter may have on any receiver. In this respect, this article analyzes the RAN slicing problem in a multi-cell network in relation to the RRM functionalities that can be used as a support for splitting the radio resources among the RAN slices. Four different RAN slicing approaches are presented and compared from different perspectives, such as the granularity in the assignment of radio resources and the degrees of isolation and customization.Peer ReviewedPostprint (author's final draft

Self-optimized admission control for multi-tenant radio access networks

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising 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.Multi-tenant Radio Access Networks (RANs) are envisaged to play a key role in highly dense scenarios for fulfilling the challenging capacity requirements of future enhanced Mobile BroadBand services while reducing the capital and operational costs per tenant. In this context, this paper proposes a self-optimized Admission Control (AC) strategy for automatically adjusting the share of resources per tenant in each cell of the shared RAN in order to account for uneven time/space distributions of tenants’ traffic demand across cells. The proposed approach is evaluated by means of simulations to analyze the operation of the self-optimization process under different traffic distributions. Results reveal that the proposed self-optimized AC can provide substantial throughput gains of up to 65% with respect to the case without self-optimization.Peer ReviewedPostprint (author's final draft

On the automation of RAN slicing provisioning and cell planning in NG-RAN

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising 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.Network slicing is a fundamental feature of 5G systems that facilitates the provision of particular system behaviours adapted to specific service/application domains on top of a common network infrastructure. While significant progress has already been achieved at specification level by 3GPP with regard to the functional support of network slicing, management solutions for the exploitation of these capabilities in the NG-RAN are still at a very incipient stage. In this context, this paper firstly presents a functional framework for the management of network slicing for a NG-RAN infrastructure, identifying the necessary information models and interfaces to support the dynamic provisioning of RAN slices. On this basis, the feasibility to automate the provisioning of RAN slices is discussed. Furthermore, a self-planning solution is presented to illustrate how a traditional network management process such as planning is expected to evolve to cope with the new challenges associated with RAN slicing management.Peer ReviewedPostprint (author's final draft

Flexible capacity sharing in multi-tenant wireless networks through fuzzy neural controllers

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising 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.The introduction of multi-tenancy in the Radio Access Network (RAN) is seen as a relevant capability of future 5G systems to support the challenging capacity requirements in a cost-effective way. Multi-tenancy brings in new challenges in the way how the RAN has to be managed and operated in order to provide the agreed service levels to each tenant and at the same time achieve an efficient utilization of the radio resources. This paper proposes a new solution for flexible capacity sharing among tenants based on a hybrid centralized/distributed Self- Organizing Network (SON) function to automatically adjust the Admission Control (AC) settings of the different cells. The proposed solution makes use of fuzzy neural controllers that provide intrinsic benefits in terms of dealing with the uncertainties of complex cellular scenarios and introducing the formulation of preferences and policies in the decision process. Together with the detailed description of the different components of the proposed solution, the paper presents an initial evaluation that provides sufficient insight into the potentials of the fuzzy neural hybrid SON to stimulate further and subsequent analysis.Peer ReviewedPostprint (author's final draft