1. nus.soc.cs5248 Ooi Wei Tsang Recent Papers from conferences

2. nus.soc.cs5248 Ooi Wei Tsang Sessions Session 1: Movies and Music Session 2: Peer-to-Peer Streaming Session 3: Power-Friendly

3. nus.soc.cs5248 Ooi Wei Tsang Movies and Music Session 1

4. nus.soc.cs5248 Ooi Wei Tsang Characterizing DVD Wu-Chi Feng et. al. Packet Video 2003

5. nus.soc.cs5248 Ooi Wei Tsang Motivations Lots of DVD videos available How are they encoded? What is the implications to our research?

6. nus.soc.cs5248 Ooi Wei Tsang DVD data 107 video streams 140 hours 80 DVDs

7. nus.soc.cs5248 Ooi Wei Tsang Bit-rates Maximum DVD bit rates 10 Mbps Found on DVD 3.3 – 7.8 Mbps VBR Quantization values change over time (only Spy Kids is CBR)

8. nus.soc.cs5248 Ooi Wei Tsang GOPs and Sequences Each GOP was encoded into a different sequence GOP sizes: around 12 frames

9. NUS.SOC.CS5248 OOI Wei Tsang nus.soc.cs5248 Ooi Wei Tsang Sequence sequence header: width height frame rate bit rate :

10. NUS.SOC.CS5248 OOI Wei Tsang nus.soc.cs5248 Ooi Wei Tsang GOP: Group of Picture gop header: time :

11. NUS.SOC.CS5248 OOI Wei Tsang nus.soc.cs5248 Ooi Wei Tsang Picture pic header: number type (I,P,B) :

12. nus.soc.cs5248 Ooi Wei Tsang Frame Patterns Most videos have varying Number of frames within a GOP Frame patterns (ID4 has 134 unique GOP patterns)

13. nus.soc.cs5248 Ooi Wei Tsang Frame Pattern Scene Change Detection used extensively IPPPPPPP quite common!

14. nus.soc.cs5248 Ooi Wei Tsang Implication to Research Cannot assume fixed frame pattern Cannot always drop B frames

15. nus.soc.cs5248 Ooi Wei Tsang Network Musical Performances UC Berkeley NOSSDAV 2001

16. nus.soc.cs5248 Ooi Wei Tsang Goal Show that networked musical performances (NMP) can be done

17. nus.soc.cs5248 Ooi Wei Tsang Observation Stanford – Berkeley (40 miles) RTT ~4 ms 0.72 meters Berkeley – Caltech (375 miles) RTT ~28 ms 4.88 meters

18. nus.soc.cs5248 Ooi Wei Tsang Observation Musical instruments have long production latency

19. nus.soc.cs5248 Ooi Wei Tsang Observation Don’t send audio, send command Keeps “states” of the current music performance

20. nus.soc.cs5248 Ooi Wei Tsang Example NoteOn(channel, note, velocity) NoteOff(channel, note)

21. nus.soc.cs5248 Ooi Wei Tsang Packet Loss Recovery Lost/Late NoteOn skipped Lost/Late NoteOff executed

22. nus.soc.cs5248 Ooi Wei Tsang Packet Loss Recovery Guard packets Recovery journals

23. nus.soc.cs5248 Ooi Wei Tsang Bandwidth 20 MIDI command per seconds 640 bps With recovery journals ~7 kbps

24. nus.soc.cs5248 Ooi Wei Tsang Experience Lost/Late NoteOn/NoteOff But musician can adjust and play fluidly

25. nus.soc.cs5248 Ooi Wei Tsang Peer-to-Peer Session 2

26. nus.soc.cs5248 Ooi Wei Tsang P2Cast Yang Guo et. al. WWW 2003

27. nus.soc.cs5248 Ooi Wei TsangNUS.SOC.CS5248 OOI WEI TSANG Patching Time Client Request mcast unicast

28. nus.soc.cs5248 Ooi Wei TsangNUS.SOC.CS5248 OOI WEI TSANG Patching Time Client Request Patching Window: W mcast

29. nus.soc.cs5248 Ooi Wei Tsang Problem with VOD IP Multicast usually assumed Patching still requires unicast connections

30. nus.soc.cs5248 Ooi Wei Tsang P2Cast

31. nus.soc.cs5248 Ooi Wei Tsang New Session

32. nus.soc.cs5248 Ooi Wei Tsang Existing Session + Patch ? ? Fat Pipe First

33. nus.soc.cs5248 Ooi Wei Tsang Patch Server Selection

34. nus.soc.cs5248 Ooi Wei Tsang Patching Stream patching stream base stream

35. nus.soc.cs5248 Ooi Wei Tsang Tree Example

36. nus.soc.cs5248 Ooi Wei Tsang Failure Recovery X

37. nus.soc.cs5248 Ooi Wei Tsang Failure Recovery What if Patch server failed? Base server failed?

38. nus.soc.cs5248 Ooi Wei Tsang PROMISE Mohamed Hafeeda et. al. ACM MM 2003

39. nus.soc.cs5248 Ooi Wei Tsang Problem P2P with streaming One peer may not have enough bandwidth Need to aggregate multiple peers

40. nus.soc.cs5248 Ooi Wei Tsang Architecture B/2 B/4 CollectCast

41. nus.soc.cs5248 Ooi Wei Tsang CollectCast Select sending peers Monitor network Assign streaming rates and data segments Decide when to change peers

42. nus.soc.cs5248 Ooi Wei Tsang PROMISE Operations I want to watch LOTR:T2T

43. nus.soc.cs5248 Ooi Wei Tsang PROMISE Operations These are the candidate s..

44. nus.soc.cs5248 Ooi Wei Tsang PROMISE Operations Max expected goodness Subject to rate constraints

45. nus.soc.cs5248 Ooi Wei Tsang PROMISE Operations Here are your peers!

46. nus.soc.cs5248 Ooi Wei Tsang PROMISE Operations Send these..

47. nus.soc.cs5248 Ooi Wei Tsang PROMISE Operations Should I switch?

48. nus.soc.cs5248 Ooi Wei Tsang PALS Reza Rejaie et. al. NOSSDAV 2003

49. nus.soc.cs5248 Ooi Wei Tsang Problem P2P with streaming One peer may not have enough bandwidth Need to aggregate multiple peers Using layered coding With congestion control

50. nus.soc.cs5248 Ooi Wei Tsang Sliding Window playout time window

51. nus.soc.cs5248 Ooi Wei Tsang Packet Assignment playout time S1S2

52. nus.soc.cs5248 Ooi Wei Tsang Sending Mechanism Request packets in priority order Sender must send in order Next request overwrites previous one

53. nus.soc.cs5248 Ooi Wei Tsang Power-Friendly Session 3

54. nus.soc.cs5248 Ooi Wei Tsang GRACE-OS Wanghong Yuan SOSP 2003

55. nus.soc.cs5248 Ooi Wei Tsang Motivation Mobile devices run on battery How to save battery?

56. nus.soc.cs5248 Ooi Wei Tsang Dynamic Voltage Scaling Example: AMD Athlon 4 PowerOn {300, 500, 600, 700, 800, 1000}MHz Energy  V 2

57. nus.soc.cs5248 Ooi Wei Tsang CPU Scheduler When to execute a task How long to execute it How fast to execute it

58. nus.soc.cs5248 Ooi Wei TsangNUS.SOC.CS5248 OOI WEI TSANG CPU Reservation “I need C units of time, out of every T units.”

59. nus.soc.cs5248 Ooi Wei Tsang Probability Distribution cycles Cum. Prob. 500 0.8 80% of the time, this task requires 500 cycle.

60. nus.soc.cs5248 Ooi Wei Tsang CPU Requirements “I need C units of time, out of every T units.” CPU only needs to run at “With 80% success rate, C is 500 cycle”

61. nus.soc.cs5248 Ooi Wei Tsang Speed Schedule speed time If task can finish early, we save energy by not running it at higher speed

62. nus.soc.cs5248 Ooi Wei Tsang Finding Speed Schedule Let task execute at speed v x during cycle x execution time: 1/v x power:  v x 2 average power:  (1-F(x))v x 2

63. nus.soc.cs5248 Ooi Wei Tsang Optimize This Minimize: Subjected to:

64. nus.soc.cs5248 Ooi Wei Tsang Implementation Linux Kernel AMD Athlon 4 716 lines of code

65. nus.soc.cs5248 Ooi Wei Tsang Findings Probability distribution is quite stable Able to meet deadlines with bounded miss ratio Save energy by 7 – 72%

66. nus.soc.cs5248 Ooi Wei Tsang Proxy Assisted Streaming Prashant Shenoy et. al. MMCN 2003

67. nus.soc.cs5248 Ooi Wei Tsang Motivation Power-aware streaming to mobile device save energy in decoding frames save energy in receiving packets

68. nus.soc.cs5248 Ooi Wei Tsang Architecture server/proxyclient Here’s my energy budget for decoding + network reception and max resolution

69. nus.soc.cs5248 Ooi Wei Tsang Architecture server/proxyclient OK, what should I send?

70. nus.soc.cs5248 Ooi Wei Tsang Information Needed Map stream properties to energy requirement Need to know decoding time of a frame

71. nus.soc.cs5248 Ooi Wei Tsang Frame Decoding Time Frame Size (bits) Time (s)

72. nus.soc.cs5248 Ooi Wei Tsang Transcoding If current stream would exceed client decoding energy budget Need to transcode by reducing quality

73. nus.soc.cs5248 Ooi Wei Tsang Transcode to what? E = estimated energy needed while E > energy budget reduce quality by ε E = estimate energy needed

74. nus.soc.cs5248 Ooi Wei Tsang Transcoded Streams server/proxyclient

75. nus.soc.cs5248 Ooi Wei Tsang Reducing NIC Energy NIC has two modes : active/sleep Client can activate NIC only when packets are expected.

76. nus.soc.cs5248 Ooi Wei Tsang Burst Transmission I will start transmitting at 10:12:54.86 pm

77. nus.soc.cs5248 Ooi Wei Tsang Evaluations Decoding Time Frame Number

78. nus.soc.cs5248 Ooi Wei Tsang Evaluations NIC Idle Uptime: 2 – 20%