Network traffic analysis and evaluation of a multi-user virtual environment

Virtual world applications allow users to interact within a simulated world. Network responsiveness and reliability contribute to the user experience, thus being able to model and reproduce certain network scenarios is a key issue to assure proper user experience and for being able to provide an estimation of the required network resources. The present study aims to model the client network traffic for the virtual world application Open Wonderland as the basis to tools for evaluating its network requirements. A micro scale modelling was performed, studying the outgoing network traffic from a black box approach that omits the details of traffic generation of the subcomponents and focuses on their overall combined traffic. The model obtained provides high goodness of fit for audio and object synchronisation traffic, reflected in a Pearson correlation coefficient close to its maximum value and low deviation figures measured by Root Mean Square Deviation.Ministerio de Ciencia e innovación IPT-2011-1038-900000Ministerio de Ciencia e innovación TEC2009-10639-C04-0

End-to-end adaptation scheme for ubiquitous remote experimentation

Remote experimentation is an effective e-learning paradigm for supporting hands-on education using laboratory equipment at distance. The current trend is to enable remote experimentation in mobile and ubiquitous learning. In such a context, the remote experimentation software should enable effective telemonitoring and teleoperation, no matter the kind of device used to access the equipment. It should also be sufficiently lenient so as to handle the rapidly evolving wireless and mobile communication environment. While the current Internet bandwidth allows remote experimentation to work flawlessly on fixed connections such as LANs, mobile users suffer from both the versatile nature of wireless communications and the limitation of the mobile devices. These conditions impose that the remote experimentation software should integrate adaptation features. For effective ubiquitous remote experimentation, it should ideally be guaranteed that the information representing the state of the remote equipment is rendered (to the end user) at the same pace at which it has been acquired, yet possibly at the cost of a somewhat minimal time delay between the acquisition and rendering phases. In this respect, an end-to-end adaptation scheme is proposed that explicitly handles the inherent variability of the connection and the versatility of the mobile devices considered in ubiquitous remote experimentation. Instead of relying on a stochastic approach, the proposed adaptation scheme relies on a deterministic mass-balance equivalence model. The effectiveness of the proposed adaptation scheme is demonstrated in critical conditions corresponding to remote experimentation carried out using a PDA over a Bluetooth link