Optimal rate allocation and scheduling in cooperative streaming

While the demand for multimedia streaming, especially from mobile devices, is growing rapidly, mobile devices are challenged by the variable transmission rate in wireless channels and limited battery capacity. In this paper, we propose an energy-efficient cooperative streaming system. In the proposed system, mobile devices collectively stream a copy of the multimedia content from the source over cellular links. The devices form a cooperative group and share received content, in coded form for efficient loss detection and recovery, with each other over short-range links. The sharing is guided by the optimal rate allocation and scheduling (RAS) algorithm that determines the amount of data and the data to be transmitted on each link. Overall, the system minimizes both the streaming traffic in the cellular network and the energy consumed by streaming applications on mobile devices. Our experimental results also show that the RAS algorithm prolongs the streaming session for the entire cooperative group.