[Studinfo] Kolloquiumsvortrag von Professor Hellwagner am kommenden Montag

Liebe Kolleginnen und Kollegen, liebe Studierende, am Montag, dem 12.05.2014 um 17:15 h spricht Herr Kollege Hellwagner von der Universität Klagenfurt in unserem Fakultätskolloquium in Raum A 5,6 C 012 über das Thema In-Network Adaptation for Adaptive Digital Video Streaming Hier das Abstract: Modern digital video portals and streaming services typically store multiple, differently encoded variants of the available videos and employ adaptation techniques in order to adapt the volume and quality of the transmitted video data, in response to, e.g., dynamically varying network throughput conditions or specific constraints of end devices. Traditionally, adaptation has been performed by the video server. Recently, though, client-driven adaptive delivery techniques have been gaining importance in practice, e.g., the standardized Dynamic Adaptive Streaming over HTTP (DASH) scheme or its proprietary variants. Besides DASH-type schemes, the Multimedia Communication research group has for several years explored yet another option, namely video adaptation in the network proper, i.e., on network devices, so-called Media-Aware Network Elements (MANEs). The talk will present experiments, results, and potential applications of this In-Network Adaptation (INA) option. We will first describe the basic design considerations, mechanisms, prototype realizations, and performance results of scalable video content (H.264/SVC) adaptation on MANEs. We have realized SVC adaptation proxies on inexpensive, Linux-based WiFi home routers and demonstrated that a reasonable number of SD SVC streams can be transmitted and adapted simultaneously. The benefits of in-network adaptation on these home routers will be illustrated by streaming HD SVC content over an IEEE 802.11 wireless network and by timely adaptation of the video according to the varying conditions on the wireless link toward a mobile client. Then we will discuss how such video adaptation mechanisms can be made use of in the context of a swarm of Unmanned Aerial Vehicles (UAVs) which explore an area, e.g., in a disaster response operation to find missing or injured persons, and transmit videos to a base station, if at all possible. In case of deteriorating network conditions, e.g., due to increasing distance from the base station, a UAV capturing a video (H.264/AVC) may autonomously reduce the video quality and data volume in order to continue delivering useful video material. The system architecture and the basis for autonomous adaptation decisions will be addressed. Alle sind herzlich dazu eingeladen. Beste Grüße, Wolfgang Effelsberg -- Prof. Dr. Wolfgang Effelsberg Tel: +49 621 181 2600 Praktische Informatik IV Fax: +49 621 181 2601 University of Mannheim effelsberg(a)informatik.uni-mannheim.de 68131 Mannheim, Germany pi4.informatik.uni-mannheim.de/~effels