1. 資工碩二 林季謙 Towards an RTP Profile for IPTV Marcel Wagner,Ivan Kopilovic,Stefan Dohla,Nikolaus Farber, and Harald Fuchs in IEEE Transcations

2. Introduction Transport protocols for IPTV MPEG2-TS In Broadcasting world RTP In Internet and mobile world

3. MPEG2-TS

5. RTP

6. End to End IPTV System Model

7. RTP IPTV Profile Allow parameter identification The receiver must be able to reconstruct the receiver side parameters of the end-to-end system model. Allow model verification It should be possible to verify the operation of a real system against the model parameters to control the encoder operation and to allow monitoring and testing Allow backward compatibility The model should extend the existing timing concepts of RTP. A conventional RTP receiver should be able to decode and play out these streams

8. RTP IPTV Profile-Base Profile Base Profile Focuses on goals 1 and 3. Provides means to estimate the required parameters with minimal changes to the timing concepts of RTP Extend Profile It can also achieve goal 2 and also provides more explicit information for parameter identification

9. Base Profile Sender Clock Synchronization RTP timestamps RTCP transmission interval

10. Extend Profile Buffering delay Random access flag Time discontinuity flag Time refinement field

11. Conclusion RTP provides more flexibility but also imposes more complexity on the receiver which in turn leads to less predictable. In order to reduce the complexity and achieve convergence between RTP and MPEG2-TS,They defines additional constraints and reduce the flexibility of RTP. THE Baseline Profile requires synchronized sender clocks and more frequent RTCP. In addition the RTP timestamp is interpreted. Similar to Mpeg2-TS.If network jitter become, The Baseline Profile cannot assure model verification The Extended Profile adds additional information to the RTP packets which provide the required information in an explicit way. Based on the proposed profiles it becomes possible to convert between MPEG2-TS and RTP in a protocol gateway or to combine MPEG2-TS service with additional RTP streams.