On the efficiency of a dedicated LMA for multicast traffic distribution in PMIPv6 domains

IP multicast allows the efficient support of group communication services by reducing the number of IP flows needed for such communication. The increasing generalization in the use of multicast has also triggered the need for supporting IP multicast in mobile environments. Proxy Mobile IPv6 (PMIPv6) is a network-based mobility management solution, where the functionality to support the terminal movement resides in the network. Recently, a baseline solution has been adopted for multicast support in PMIPv6. Such base solution has inefficiencies in multicast routing because it may require multiple copies of a single stream to be received by the same access gateway. Nevertheless, there is an alternative solution to support multicast in PMIPv6 that avoids this issue. This paper evaluates by simulation the scalability of both solutions under realistic conditions, and provides an analysis of the sensitivity of the two proposals against a number of parameters.

Dynamic Analysis of high Speed Railway Traffic Loads on Ballasted Track

This paper reports the studies carried out to develop and calibrate the optimal models for the objectives of this work. In particular, quarter bogie model for vehicle, rail-wheel contact with Lagrangian multiplier method, 2D spatial discretization were selected as the optimal decisions. Furthermore, the 3D model of coupled vehicle-track also has been developed to contrast the results obtained in the 2D model. The calculations were carried out in the time domain and envelopes of relevant results were obtained for several track profiles and speed ranges. Distributed elevation irregularities were generated based on power spectral density (PSD) distributions. The results obtained include the wheel-rail contact forces, forces transmitted to the bogie by primary suspension. The latter loads are relevant for the purpose of evaluating the performance of the infrastructure

Habilitadores para aplicación de teleconsulta sobre IP Multimedia Subsystem

En el presente trabajo se presenta el diseño e implementación de un conjunto de habilitadores o servicios genéricos para aplicaciones de teleconsulta sobre redes IMS. A partir de las funcionalidades identificadas en las aplicaciones de teleconsulta se han diseñado los habilitadores a desarrollar, que son los siguientes: una sala de espera virtual, una pizarra virtual y una multiconferencia multimedia. Estos servicios utilizan a su vez otros habilitadores genéricos referidos en el estado del arte de la arquitectura IMS. Tales servicios se han integrado en una arquitectura IMS para garantizar su funcionamiento. Para evaluar el funcionamiento de los habilitadores desarrollados se ha definido e implementado el caso de uso de una aplicación de teleconsulta avanzada.

e-MIS Contents: Multimedia Contents for e-Learning Environments in Minimally Invasive Surgery

This work describes the design and application of multimedia contents for web technologies-based training in minimally invasive surgery (MIS). The chosen strategy allows knowing the deficiencies of the current training methods so new multimedia contents can cover them. This study is concluded with the definition of three different types of multimedia contents accordingly to the development degree and didactic objectives that they present: Didactic resources are basic contents such as videos or documents that can be enhanced with contributions of users. On the other hand, case reports and didactic units have a defined structure. Didactic resources and case reports provide an informal training while didactic units are included in a more regulated training.