1. 1 P2P Layer Streaming for Heterogeneous Networks in PPSP K. Wu, Z. Lei, D. Chiu Kent Kangheng Wu 9/11/2010

2. 2 Heterogeneous Networks 1)Scenario PCs, set-top boxes and mobile devices may all need to access and provide service for the same content. 2)Problems Use multiple versions of video content (each encoded at different resolution or visual quality). Peers in different versions will not help each other. The overall video quality received will not be optimal.

3. 3 An Example

4. 4 P2P Layer Streaming

5. 5 Layer Video 1)Single layer Video All peers receive the same video quality 2)Layered video A video is encoded into several layers More layers introduce better video quality Nested dependence between layers A higher layer can be decoded only if all the lower layers are available 3)Higher upload contribution results in better received video quality

6. 6 Multiple Description Coding 1)Video encoding/decoding technology Video content is encoded into several descriptions Each description can be decoded independently Even receiver only receives one description, the video is displayed with low quality The more descriptions received, the better video quality Compared with layered streaming, multiple description has lower coding efficiency and worse performance. encoding MDC Video content decoding MDC # of description Videoquality

7. 7 Message Flows 1)PUT-LAYER (Put Layer Information) into Tracker 2)GET-LAYER (Get Layer Information) from Tracker 3)PUT-CHUNK (Put Chunk Information) into Tracker 4)GET-PEERLIST (Peer Selection) 5)LAYER-CHANGE (Layer Change) 6)STATISTICS

8. 8 Open issues 1)Data Scheduling Different strategy with single layer streaming 2)System Performance Metrics Throughput and Delay Layer Delivery Ratio Useless Packets Ratio Jitter Prevention 3)User Performance Metrics Start-up Delay Playback Continuity Playback Delay

9. 9 End of Presentation Thank you. Do you have any questions? Our corporate website: www.astri.org