1. NUS.SOC.CS5248 Ooi Wei Tsang Rate Adaptations

2. NUS.SOC.CS5248 Ooi Wei Tsang You are Here Network Encoder Sender Middlebox Receiver Decoder

3. NUS.SOC.CS5248 Ooi Wei Tsang Sender’s Algorithm open UDP socket foreach video frame chop into packets add RTP header send to network

4. NUS.SOC.CS5248 Ooi Wei Tsang Sender’s Algorithm open UDP socket foreach video frame chop into packets add RTP header send to network wait for 1/fps seconds

5. NUS.SOC.CS5248 Ooi Wei Tsang Sender’s Algorithm open UDP socket foreach video frame chop into packets foreach packet add RTP header send to network wait for size/bps seconds

6. NUS.SOC.CS5248 Ooi Wei Tsang Rules Transmission rate should match encoding rate Transmission should not be too bursty

7. NUS.SOC.CS5248 Ooi Wei Tsang Two Approaches Just send at a fix rate or “I hope the network can handle it” approach”

8. NUS.SOC.CS5248 Ooi Wei Tsang Effects on TCP: Simulation From Sisalem, Emanuel and Schulzrinne paper on “Direct Adjustment Algorithm”

9. NUS.SOC.CS5248 Ooi Wei Tsang Effects on TCP

10. NUS.SOC.CS5248 Ooi Wei Tsang Demo Effects of UDP on TCP without congestion control

11. NUS.SOC.CS5248 Ooi Wei Tsang Two Approaches Just send at a fix rate or “I hope the network can handle it” approach” Adapt transmission/encoding rate to network condition

12. NUS.SOC.CS5248 Ooi Wei Tsang How to Adapt? if network condition is bad reduce rate else if network condition is so-so do nothing else if network condition is good increase rate

13. NUS.SOC.CS5248 Ooi Wei Tsang How to.. Know “network condition is bad”? increase/decrease rate?

14. NUS.SOC.CS5248 Ooi Wei Tsang if network condition is bad else if network condition is so-so do nothing else if network condition is good Adapting Output Rate

15. NUS.SOC.CS5248 Ooi Wei Tsang Question: What should  and be?

16. NUS.SOC.CS5248 Ooi Wei Tsang Observation 1 Should never change your rate more than an equivalent TCP

17. NUS.SOC.CS5248 Ooi Wei Tsang Observation 2  and should depend on network conditions and current rate.

18. NUS.SOC.CS5248 Ooi Wei Tsang Goal: Fair Share of Bottleneck let rr : current rate b: bottleneck bandwidth S: current share

19. NUS.SOC.CS5248 Ooi Wei Tsang S vs 1 S

20. NUS.SOC.CS5248 Ooi Wei Tsang Value of (Assuming one receiver)

21. NUS.SOC.CS5248 Ooi Wei Tsang Limit of M: packet size  : round trip time T : period between evaluation of

22. NUS.SOC.CS5248 Ooi Wei Tsang Limit of M : packet size  : round trip time T : period between evaluation of

23. NUS.SOC.CS5248 Ooi Wei Tsang loss rate vs   loss rate 1 1

24. NUS.SOC.CS5248 Ooi Wei Tsang Value of  where is the loss rate k is a constant (Assuming one receiver)

25. NUS.SOC.CS5248 Ooi Wei Tsang

26. NUS.SOC.CS5248 Ooi Wei Tsang What is Needed?

27. NUS.SOC.CS5248 Ooi Wei Tsang Estimating b : Packet Pair

28. NUS.SOC.CS5248 Ooi Wei Tsang Estimating b : Packet Pair

29. NUS.SOC.CS5248 Ooi Wei Tsang Estimating b : Packet Pair

30. NUS.SOC.CS5248 Ooi Wei Tsang Evaluation

31. NUS.SOC.CS5248 Ooi Wei Tsang More TCP-Friendly Rate Control

32. NUS.SOC.CS5248 Ooi Wei Tsang TCP-Equation Window size behavior in TCP/IP with constant loss probability T. Ott, J. Kemperman, and M. Mathis June 1997, HPCS 1997

33. NUS.SOC.CS5248 Ooi Wei Tsang TCP-Equation Equation-Based Congestion Control for Unicast Applications Sally Floyd, Mark Handley, Jitendra Padhye, and Joerg Widmer. August 2000. SIGCOMM 2000

34. NUS.SOC.CS5248 Ooi Wei Tsang Another Transport Protocol Datagram Congestion Control Protocol (DCCP) Implements congestion control but not reliability

35. NUS.SOC.CS5248 Ooi Wei Tsang Rules Transmission rate should match encoding rate Transmission should not be too bursty

36. NUS.SOC.CS5248 Ooi Wei Tsang Rate Control Given a rate, how to encode the video with the given rate?

37. NUS.SOC.CS5248 Ooi Wei Tsang Reduce Frame Rate Live Video Stored Video

38. NUS.SOC.CS5248 Ooi Wei Tsang Reduce Frame Resolution Live Video Stored Video

39. NUS.SOC.CS5248 Ooi Wei Tsang Increase Quantization Live Video Stored Video

40. NUS.SOC.CS5248 Ooi Wei Tsang Drop AC components Live Video Stored Video

41. NUS.SOC.CS5248 Ooi Wei Tsang Trouble with Stored Video Reducing rate requires partial decoding and re-encoding Solution: Layered Video

42. NUS.SOC.CS5248 Ooi Wei Tsang Layered Video or “Scalable Video”

43. NUS.SOC.CS5248 Ooi Wei Tsang Layered Video Layer 1 Layer 2Layer 3

44. NUS.SOC.CS5248 Ooi Wei Tsang Layering Scheme Temporal Layering

45. NUS.SOC.CS5248 Ooi Wei Tsang Layering Scheme Spatial Layering

46. NUS.SOC.CS5248 Ooi Wei Tsang Layering Scheme DCT Layering 308 -6 20 00 10 00 00 00 308 -6 2 1 30

47. NUS.SOC.CS5248 Ooi Wei Tsang Layering Scheme Fine Granularity Scalability (FGS) 1000010010000100 1001010110010101 1110001011100010 1100000011000000

48. NUS.SOC.CS5248 Ooi Wei Tsang Rate Adaptation To increase rate, send more layers To decrease rate, drop some layers

49. NUS.SOC.CS5248 Ooi Wei Tsang MS Windows Streaming Media

50. NUS.SOC.CS5248 Ooi Wei Tsang Intelligent Streaming Multiple-Bit-Rate Encoding Intelligent Bandwidth Control bit rate selection thinning Intelligent Image Processing

51. NUS.SOC.CS5248 Ooi Wei Tsang Intelligent Streaming How exactly does it work? Sorry, it’s proprietary

52. NUS.SOC.CS5248 Ooi Wei Tsang Is WSM TCP friendly? Measurements of the Congestion Responsiveness of Windows Streaming Media J. Nichols et. al., NOSSDAV 2004 All figures taken from the original NOSSDAV presentation

53. NUS.SOC.CS5248 Ooi Wei Tsang

54. NUS.SOC.CS5248 Ooi Wei Tsang 340kbps clip, 725kbps bottleneck

55. NUS.SOC.CS5248 Ooi Wei Tsang Transmission is Bursty

56. NUS.SOC.CS5248 Ooi Wei Tsang 340kbps clip, 725kbps bottleneck

57. NUS.SOC.CS5248 Ooi Wei Tsang 548kbps Clip - 725kbps Bottleneck

58. NUS.SOC.CS5248 Ooi Wei Tsang 1128kbps Clip - 725kbps Bottleneck

59. NUS.SOC.CS5248 Ooi Wei Tsang 725kbps Bottleneck BufferingPlayout Single Encoded Bit Rate

60. NUS.SOC.CS5248 Ooi Wei Tsang 725kbps Bottleneck Multiple Encoded Bit Rate BufferingPlayout

61. NUS.SOC.CS5248 Ooi Wei Tsang Conclusion Two phases: buffering + playout Not always TCP-friendly