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Broadcasting live video directly from mobile devices is rapidly gaining popularity with applications like Periscope and Facebook Live. The quality of experience (QoE) provided by these services comprises many factors, such as quality of transmitted video, video playback stalling, end-to-end latency, and impact on battery life, and they are not yet well understood. In this article, we examine mainly the Periscope service through a comprehensive measurement study and compare it in some aspects to Facebook Live. We shed light on the usage of Periscope through analysis of crawled data and then investigate the aforementioned QoE factors through statistical analyses as well as controlled small-scale measurements using a couple of different smartphones and both versions, Android and iOS, of the two applications. We report a number of findings including the discrepancy in latency between the two most commonly used protocols, RTMP and HLS, surprising surges in bandwidth demand caused by the Periscope app's chat feature, substantial variations in video quality, poor adaptation of video bitrate to available upstream bandwidth at the video broadcaster side, and significant power consumption caused by the applications. [ABSTRACT FROM AUTHOR]

A large amount of educational resources are currently available in the Internet, covering educational needs for many school grades. However, using such wealth of material, typically dispersed in several repositories, in a simple and effective way, is rather challenging due to the difficulties encountered by teachers in learning the peculiar access and operational procedures that each repository system requires. Therefore, it is important to provide the teachers with a centralized, integrated, simple system that can address most of their needs so that every operation (search, edit, share, download) can be done from a single location. This work follows this direction by designing and presenting both an architecture to integrate different repository systems using the Content Management Interoperability Services (CMIS) API and an integration layer that provides a simple web interface suitable for the needs of both the content creators (teachers) and the users of the contents (learners). Results have been evaluated both quantitatively, i.e., using performance indicators such as response time, and qualitatively, on the basis of the user experience evaluated through a questionnaire. Both type of results show that the platform adequately addresses user needs therefore it has the potential to be embraced by a large user community. [ABSTRACT FROM AUTHOR]