Análisis y procesado de medidas de parámetros de banda estrecha utilizando un smartphone con sistema operativo Android

La medición de los parámetros de RF en las redes celulares es de suma importancia para la caracterización del canal de banda estrecha. Para el mejor conocimiento, no existe ninguna aplicación Android test drive disponible actualmente que captura los parámetros de la señal de RF a lo largo de un camino. Por consiguiente, hemos programado una aplicación Android para smartphones que mide la potencia de RF recibida a lo largo de un camino. Esta aplicación calcula la posición del teléfono inteligente utilizando las coordenadas geográficas proporcionadas por el GPS. También calculamos la distancia aproximada entre la estación base y el teléfono inteligente con la base de datos de las estaciones base proporcionadas por Google. Por último, se ha realizado una campaña de medidas en calles anchas y calles estrechas de la ciudad de Valencia. Y asi, hemos obtenido el exponente de propagación y la desviación estándar de shadowing para ambos ambientes.The measurement of RF parameters in cellular networks is of paramount importance for the characterization of the narrowband channel. To the author best knowledge, no Android test drive application is currently available which captures RF signal parameters along a path. Therefore we have programmed an Android application for smartphones which measures RF power received along a path. This application calculates the position of the smartphone by using the geographic coordinates provided by its GPS. We also estimate the distance between the base station and the smartphone with the base station data base location from Google. Finally, a simple measurement campaign has been carried out in both wide streets and narrow streets of Valencia. Thus, we have obtained the propagation exponent and the standard deviation of the shadowing for both environments.Carrillo Padilla, WR. (2013). Análisis y procesado de medidas de parámetros de banda estrecha utilizando un smartphone con sistema operativo Android. http://hdl.handle.net/10251/35013.Archivo delegad

Design and implementation of an on-line demonstrator for a video telephony system over heterogeneus networks

In recent times, Next Generation Mobile Networks (NGMN) enable user's mobility, not needing to be in a fixed place anymore. For this service to be successful, seamless transitions between the different technologies become essential, in order to make possible the always best connected goal. This brings an additional problematic, which is the impairments resulting from a handover between two networks. In order to succesfully plan and continue the development of always on services and mobility management, the approach must be based on user's perception of phenomena such us packet loss, the so-called Quality of Experience (QoE). This is the context in which Mobisense was born, intending a better understanding of NGMN transmission phenomena and resulting quality. Hence, Mobisense project is focused on the evaluation of the quality of service from user's point of view and on the seamless switch provision between video codecs when connections are transferred between two networks. On that purpose, a NGMN test environment was developed for real-time multimedia services. In this environment, specific network conditions can be associated with user's assessments within a realistic model. Mobisense project creates the foundations for the employment of advance prediction methods for real-time mobility management, to make decisions depending on the characteristics measured in the network and the predictions of quality resulting from them. The present degree final project gathers the work carried out to develop an extension for Mobisense testbed, in order to deploy it in a real environment of network technologies, as well as the integration with Quality of Service (QoS) algorithms. Therefore, the aim of this project consists on the development of the software required for the creation of a video thelephony system over NGMN, taking Mobisense and MultiRAT testbeds as starting point. Mobisense brings adaptation in the application layer and user's perception, and MultiRAT provides QoS adaptation and new wireless technologies. Both testbeds combined to explore more QoE aspects in wireless networks of tomorrow.En los últimos tiempos, las NGMN posibilitan la movilidad del usuario, sin ser ya necesaria su permanencia en un lugar fijo. Para el éxito de este servicio se hacen indispensables transiciones continuas entre las diferentes tecnologías, de manera que sea posible el objetivo de "siempre la mejor conexión". Esto lleva consigo una problemática adicional, que son las de ciencias resultantes del handover entre dos redes. Para planificar y continuar satisfactoriamente el desarrollo de servicios always on y la gestión de la movilidad, el enfoque debe ser en base a la percepción del usuario de fenómenos tales como la pérdida de paquetes, la llamada QoE. En este contexto nació el proyecto Mobisense, buscando una mejor comprensión del fenómeno de transmisión NGMN y la calidad resultante. El proyecto Mobisense se centra, por tanto, en la evaluación de la calidad de servicio desde el punto de vista del usuario y en la provisión de cambios continuos entre codecs de vídeo al transmitirse conexiones entre dos redes. Para tal propósito, un entorno de pruebas NGMN fue desarrollado para servicios multimedia en tiempo real. En este entorno, pueden asociarse determinadas condiciones en la red con valoraciones de calidad por parte del usuario en un modelo realista. El proyecto Mobisense sienta las bases para el empleo de métodos avanzados de predicción para la gestión de movilidad en tiempo real, para tomar decisiones dependientes de las características de la red medidas y de las predicciones de calidad derivadas a partir de éstas. El presente proyecto de fin de carrera recoge el trabajo realizado para desarrollar una extensión del testbed Mobisense, de cara a desplegarlo en un entorno real de tecnologías de red, así como la integración de algoritmos de QoS. Por tanto, el objeto de este proyecto consiste en el desarrollo software requerido para la creación de un sistema de videotelefonía sobre NGMN, tomando los testbeds Mobisense y MultiRAT como punto de partida. Mobisense aporta adaptación en la capa de aplicación y la percepción de usuario, y MultiRAT proporciona adaptación QoS y nuevas tecnologías de red. Ambos testbeds se combinan para la exploración más amplia de los aspectos de QoE en las redes inalámbricas del mañana.Ingeniería de Telecomunicació

Enhanced Quality of Experience Based on Enriched Network Centric and Access Control Mechanisms

In the digital world service provisioning in user satisfying quality has become the goal of any content or network provider. Besides having satisfied and therefore, loyal users, the creation of sustainable revenue streams is the most important issue for network operators [1], [2], [3]. The motivation of this work is to enhance the quality of experience of users when they connect to the Internet, request application services as well as to maintain full service when these users are on the move in WLAN based access networks. In this context, the aspect of additional revenue creation for network operators is considered as well. The enhancements presented in this work are based on enriched network centric and access control mechanisms which will be achieved in three different areas of networks capabilities, namely the network performance, the network access and the network features themselves. In the area of network performance a novel authentication and authorisation method is introduced which overcomes the drawback of long authentication time in the handover procedure as required by the generic IEEE 802.1X process using the EAP-TLS method. The novel sequential authentication solution reduces the communication interruption time in a WLAN handover process of currently several hundred milliseconds to some milliseconds by combining the WPA2 PSK and the WPA2 EAP-TLS. In the area of usability a new user-friendly hotspot registration and login mechanisms is presented which significantly simplifies how users obtain WLAN hotspot login credentials and logon to a hotspot. This novel barcode initiated hotspot auto-login solution obtains user credentials through a simple SMS and performs an auto-login process that avoids the need to enter user name and password on the login page manually. In the area of network features a new system is proposed which overcomes the drawback that users are not aware of the quality in which a service can be provided prior to starting the service. This novel graceful denial of service solution informs the user about the expected application service quality before the application service is started