Design and evaluation of a DASH-compliant second screen video player for live events in mobile scenarios

The huge diffusion of mobile devices is rapidly changing the way multimedia content is consumed. Mobile devices are often used as a second screen, providing complementary information on the content shown on the primary screen, as different camera angles in case of a sport event. The introduction of multiple camera angles poses many challenges with respect to guaranteeing a high Quality of Experience to the end user, especially when the live aspect, different devices and highly variable network conditions typical of mobile environments come into play. Due to the ability of HTTP Adaptive Streaming (HAS) protocols to dynamically adapt to bandwidth fluctuations, they are especially suited for the delivery of multimedia content in mobile environments. In HAS, each video is temporally segmented and stored in different quality levels. Rate adaptation heuristics, deployed at the video player, allow the most appropriate quality level to be dynamically requested, based on the current network conditions. Recently, a standardized solution has been proposed by the MPEG consortium, called Dynamic Adaptive Streaming over HTTP (DASH). We present in this paper a DASH-compliant iOS video player designed to support research on rate adaptation heuristics for live second screen scenarios in mobile environments. The video player allows to monitor the battery consumption and CPU usage of the mobile device and to provide this information to the heuristic. Live and Video-on-Demand streaming scenarios and real-time multi-video switching are supported as well. Quantitative results based on real 3G traces are reported on how the developed prototype has been used to benchmark two existing heuristics and to analyse the main aspects affecting battery lifetime in mobile video streaming

A user perspective of quality of service in m-commerce

This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2004 Springer VerlagIn an m-commerce setting, the underlying communication system will have to provide a Quality of Service (QoS) in the presence of two competing factors—network bandwidth and, as the pressure to add value to the business-to-consumer (B2C) shopping experience by integrating multimedia applications grows, increasing data sizes. In this paper, developments in the area of QoS-dependent multimedia perceptual quality are reviewed and are integrated with recent work focusing on QoS for e-commerce. Based on previously identified user perceptual tolerance to varying multimedia QoS, we show that enhancing the m-commerce B2C user experience with multimedia, far from being an idealised scenario, is in fact feasible if perceptual considerations are employed

noteEd - A web-based lecture capture system

Electronic capture and playback of lectures has long been the aim of many academic projects. Synote is an application developed under MACFoB (Multimedia Annotation and Community Folksonomy Building) project to synchronise the playback of lecture materials. However, Synote provides no functionality to capture such multimedia. This project involves the creation of a system called noteEd, which will capture a range of multimedia from lectures and make them available to Synote. This report describes the evolution of the noteEd project throughout the design and implementation of the proposed system. The performance of the system was checked in a user acceptance test with the customer, which is discussed after screenshots of our solution. Finally, the project management is presented containing a final project evaluation

Remote fieldwork: using portable wireless networks and backhaul links to participate remotely in fieldwork

Fieldwork is an important means of contextualising knowledge and developing subject-specific and generic transferable skills. However, field locations are not always accessible. To address this problem we present a remote fieldwork approach that makes use of a portable wireless network and other mobile technologies to support fieldwork at a distance. As well as improving access to fieldwork, this approach can also be used to provide communication tools to fieldworkers, enabling them to share their findings and talk to their colleagues while in the field. This paper presents the portable communications toolkit we have developed and reports on three recent trials