ColStream: Collaborative streaming of on-demand videos for mobile devices

The number of mobile users of on demand video is growing rapidly. However, bandwidth fluctuation in the 3G/LTE technologies is an obstacle in providing high quality smooth video playout for users on the go. In this paper, we present ColStream that can aggregate bandwidth from ubiquitous devices to ensure high quality video streaming with minimal stalling time. ColStream dynamically adjusts the set of collaborators and the size of video chunks that the collaborators need to pre-fetch ahead of the video chunks playout time to provide smooth video playout. ColStream uses a multi-objective optimisation method to maximise bandwidth and minimise cost. ColStream requires neither external servers nor proxies to provide its functionality. The paper describes the ColStream functionality, architecture, applied algorithms, ColStream prototype, and evaluation of its suitability for effective video streaming in mobile environments.