Transitions on Multiple Layers for Scalable, Energy-Efficient and Robust Wireless Video Streaming

This work demonstrates the effects of multi-layer adaptivity for a wireless live video streaming scenario. We investigate a specific type of adaptations, the so-called transitions, which switch between different network mechanisms during the runtime of an application. In comparison to a pure configuration adaptation, a transition is beneficial because a system may select those mechanisms that perform best under varying environmental conditions. We consider transitions on the overlay (by switching between different stream delivery schemes on the application layer) as well as on the underlay (by switching between different wireless topologies). At the beginning of our demonstration, some few devices receive the video stream from a central server. Then, additional devices start receiving the video stream. Under these circumstances, a transition from the client/server delivery scheme to a decentralized peer-to-peer based video streaming improves scalability. On the underlay, video stream delivery benefits from topology control mechanisms, which select specific wireless neighbors in order to restrict communication to energy-efficient communication links. However, topology control also reduces the robustness of the underlay topology. Thus, when devices that are critical nodes in the wireless network are on the verge of running out of energy, we conduct a transition to a more robust underlay topology. In summary, by performing transitions jointly on multiple layers, we demonstrate resulting improvements of energy efficiency, scalability and robustness.