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Current e-learning forms are commonly based on improving the learning process through the enhancement of certain skills in students, such as collaborative, competitive or problem-based learning. However, it seems that there is still no e-learning "formula" that gathers the implementation of a number of more generic educational principles in a single e-learning system or platform. Therefore, this paper presents a web-based framework for the creation, development and implementation of heterogeneous learning environments called CADI. It offers a graphical user interface for students to interact with only the need for any generic WiFi compliant device. Its innovative design allows the instructor to select and combine the developed resources to create varied activities, providing content adapted to every single device. The usefulness of the system was tested by introducing a case study to a group of senior college students. The experience showed that the use of the system helped students to achieve better results in their evaluation. It also showed that the students had no problems interacting with it from the outset, promoting their active learning. Design, implementation and assessment results of the system are also presented and analyzed. (Contains 6 tables and 9 figures.)

A successful deployment of multimedia applications over wireless environments entails improving the quality of service (QoS), not only from a technical point of view, but also considering the quality of experience (QoE) from the final user's perception. Although objective QoE measure models avoid the difficulties of subjective surveys, subjective QoE assessments are essential to understand the way users evaluate the QoS. In this work, we study the effect of a wide range of parameters on the QoE of VVoIP applications in a real wireless scenario. Through a complete statistical analysis of users' ratings, we identify the following facts. Although the use of VVoIP in wireless networks does not yet represent an advantage for users, there are great expectations for all applications under study, and with greater popularity comes higher expectations. It is easier for respondents to identify good behavior than poor behavior. Whereas the respondents' frequency of Internet use does not impact on the scores, respondents' gender does. Finally, the most determining parameters of quality from a user's perspective were instability, video quality, voice distortion, usefulness, and graphical interface. [ABSTRACT FROM AUTHOR]

Abstract: The current trend in telecommunications networks addresses an All-IP vision, since most user applications are based on IP, and additionally, IP networks operation is simpler than other more complex ones. These new trends in multimedia communications are giving rise to an increasing need of quality of service (QoS). The Differentiated Services (DiffServ) QoS architecture will provide the means to help underlying technologies, like MPLS, to guarantee the QoS required to support data and real-time services. In DiffServ, QoS is mainly provided with traffic control at edge nodes, and this task is carried out by traffic conditioners. In this paper, we introduce a new policy function for traffic conditioning. Its ability to react to new network conditions makes end-users to get excess bandwidth in proportion to their contracted target rates. We call this method Proportional Excess Traffic conditionER (PETER). Through extensive simulations, we confirm the effectiveness of our approach in providing both a proportional excess bandwidth distribution and assured contracted target rates. [Copyright &y& Elsevier]

Provides an overview of the Spanish Plan of Scientific Research, Development and Technological Innovation for 2000-2003 in Spain. Aim of the plan; Elements of the plan; Investment of Spain in research and development.