Herramienta software para el análisis de rendimiento de redes 4G

[ES]El objetivo de este proyecto ha sido desarrollar una herramienta software que permita medir el rendimiento de redes con tecnología móvil 4G, también conocida como LTE. Para ello se ha creado un sistema software que está compuesto por una aplicación móvil y un servidor de aplicaciones. El sistema en conjunto realiza la función de recoger indicadores de calidad de la red móvil de diversa índole, que posteriormente son procesados utilizando herramientas software matemáticas, para así obtener gráficas y mapas que permiten analizar la situación y el rendimiento de una red 4G concreta. El desarrollo del software ha llegado a nivel de prototipo y se han realizado pruebas reales con él obteniendo resultados positivos de funcionamiento.

Desarrollo de cliente OMA PoC para Android

[ES]Se presenta el siguiente proyecto de desarrollo, enfocado en el contexto de suplir las necesidades de los equipos de emergencias. Actualmente los equipos de emergencias, hacen uso de walkie talkies para comunicarse entre sí, es decir, hacen uso de la tecnología PTT (Push-to-talk). Es una comunicación unidireccional de un usuario a muchos, de manera que pueden transmitir la información necesaria a varios usuarios simultáneamente. Por otra parte, la comunicación mediante esta tecnología hace posible que sea en tiempo real sin prácticamente ningún retraso. Sin embargo el uso de esta forma de comunicación trae consigo algunos inconvenientes. Por ejemplo, los dispositivos tienen un rango de alcance de transmisión-recepción limitado. Además la banda de frecuencia para poder comunicarse debe ser reservada a fin de evitar posibles problemas de comunicación debido a que el canal estuviera ocupado por otros usuarios, posibles interferencias, etc. La reserva de este rango de frecuencia, supone un coste añadido para el uso de esta tecnología. Con el desarrollo de las redes móviles que ofrecen grandes velocidades de transmisión, se hace posible el uso de la tecnología PTT mediante la red móvil existente. De esta manera, surge el siguiente proyecto de desarrollo de una aplicación móvil Android, como cliente que haga uso de la tecnología PTT sobre la red móvil PoC (Push-to-talk Over Cellular).

Modelling and Simulation of ERTMS for Current and Future Mobile Technologies

Nowadays, train control in-lab simulation tools play a crucial role in reducing extensive and expensive on-site railway testing activities. In this paper, we present our contribution in this arena by detailing the internals of our European Railway Train Management System in-lab demonstrator. This demonstrator is built over a general-purpose simulation framework, Riverbed Modeler, previously Opnet Modeler. Our framework models both ERTMS subsystems, the Automatic Train Protection application layer based on movement authority message exchange and the telecommunication subsystem based on GSM-R communication technology. We provide detailed information on our modelling strategy. We also validate our simulation framework with real trace data. To conclude, under current industry migration scenario from GSM-R legacy obsolescence to IP-based heterogeneous technologies, our simulation framework represents a singular tool to railway operators. As an example, we present the assessment of related performance indicators for a specific railway network using a candidate replacement technology, LTE, versus current legacy technology. To the best of our knowledge, there is no similar initiative able to measure the impact of the telecommunication subsystem in the railway network availability.

Seasonal Stability Tests in gretl. An Application to International Tourism Data

The seasonal stability tests of Canova & Hansen (1995) (CH) provide a method complementary to that of Hylleberg et al. (1990) for testing for seasonal unit roots. But the distribution of the CH tests are unknown in small samples. We present a method to numerically compute critical values and P-values for the CH tests for any sample size and any seasonal periodicity. In fact this method is applicable to the types of seasonality which are commonly in use, but also to any other.

Reuse of software components orientated to iOS mobile devices

Within the next few pages, I will try to give a wide description of the project that I have been doing for IK4-Ikerlan. For the last six months, I have been working in developing a socket-based application for Apple devices. These devices work under the iOS operative system, which is programmed in Objective-C, a language similar to C. Although I did not have the chance to develop this application for Apple TV, I was able to create an application for iPhone and another one for iPad. The only difference between both applications was the screen resolution, but we decided to make them separately, as it would be really hard to combine both resolutions, and wallpapers, everything in the same workspace. Finally, it is necessary to add that the main goal was not to create a new application for iOS, but to translate an Android application into iOS. To achieve this, it is required to translate Java code into Objective- C, which is the language used to develop applications for all kinds of Apple devices. Fortunately, there is a tool created by Google, which helped us with this exercise. This tool is called j2ObjC, and it is still being developed.

Testing the performance and feasibility of Bluetooth communications in pervasive systems

Smart and mobile environments require seamless connections. However, due to the frequent process of ''discovery'' and disconnection of mobile devices while data interchange is happening, wireless connections are often interrupted. To minimize this drawback, a protocol that enables an easy and fast synchronization is crucial. Bearing this in mind, Bluetooth technology appears to be a suitable solution to carry on such connections due to the discovery and pairing capabilities it provides. Nonetheless, the time and energy spent when several devices are being discovered and used at the same time still needs to be managed properly. It is essential that this process of discovery takes as little time and energy as possible. In addition to this, it is believed that the performance of the communications is not constant when the transmission speeds and throughput increase, but this has not been proved formally. Therefore, the purpose of this project is twofold: Firstly, to design and build a framework-system capable of performing controlled Bluetooth device discovery, pairing and communications. Secondly, to analyze and test the scalability and performance of the \emph{classic} Bluetooth standard under different scenarios and with various sensors and devices using the framework developed. To achieve the first goal, a generic Bluetooth platform will be used to control the test conditions and to form a ubiquitous wireless system connected to an Android Smartphone. For the latter goal, various stress-tests will be carried on to measure the consumption rate of battery life as well as the quality of the communications between the devices involved.

Plastic Analysis and Testing of multidirectional SFRC flag slabs

This paper presents a theoretical and experimental study of multidirectional steel fibers reinforced concrete slabs (SFRC). The study is based on a real building application using SFRC flag slabs. For the evaluation of the slabs bearing capacity, plastic calculations are performed both at section and structure levels. The section analysis uses the perfect plastic stress-strain diagram, with reference to the values of the strength characteristics of SFRC based on previous jobs that used similar fibers and dosages. In the structure analysis the plastic yield lines method has been used. This method relates the section last bearing moment and the plastic collapse load. The experimental campaign has consisted of the testing of six 2 m. diameter circular shaped slabs prototypes, and has allowed to verify the reference resistance used in the calculations.