CS525z Multimedia Networking

1
CS525zMultimedia Networking

• Review

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Analog to Digital

• What is the relationship between
• Fidelity and Sample Size
• Fidelity and Sample Rate

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Audio

• What are typical voice quality audio rates?
• What are typical music quality audio rates?
• Why are they different?

4
Graphics

• What is a pel/pixel?
• What are the components of a graphic image?

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Frame Rate

• What frame rate is full motion video?
• What is a lower bound on acceptable frame rates?

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Effects of Delay

• What are typical delay bounds for
• Interactive multimedia
• Streaming multimedia
• Web browsing

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Jitter

• What is one technique that can be used to remove
  jitter?
• What is a drawback with this technique?

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Speech Detection

• Why do speech detection?
• What are the challenges with speech detection in
  many typical computing environments?

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Speech Detection

• What is the definition of energy in a sound
  sample?
• What is the definition of zero crossing rate?
• How are they both used in RS75?

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Video Compression

• What is spatial compression?
• What is temporal compression?

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MPEG Compression

• What is an I-frame?
• What is a P-frame?
• What is a B-frame?
• What is a Group of Pictures (GOP)?

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MPEG Compression

• Why not have all I-frames in a GOP?
• Why not have all B-frames in a GOP?

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Computer Science

• What are the steps in the scientific methodology?
• True or False
• Every computer science experiment needs to
  evaluate a proposed solution
• All experimental data gathered should be
  presented in the analysis

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LHPT95

• What is their hypothesis?
• What is their methodology?
• What is one of their observations?

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LHPT95

• What are some of the possible sources of error in
  their experimental methodology?
• Which do they address?

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WS00

• What is their (implicit) hypothesis?

17
WS00

• What are some of the possible non-network related
  degradations they identify?

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MH00

• What is their methodology?
• True or False (based on the paper)
• Most RealAudio uses TCP
• RealAudio can use 2 flows, one for control and
  one for data
• RealAudio is CBR over all time scale
• What are some other uses of the results from the
  paper?

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BID02

• What is the motivation of their paper?
• What is their methodology?
• What is a major finding?
• True or False
• The Internet provides VoIP equivalent to phones
• If we made routing reliable, the Internet would
  provide VoIP equivalent to phones

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SJ95

• What is the E-Policy?
• What is the I-Policy?
• When, in general, is the E-Policy good?
• When, in general, is the I-Policy good?
• What is a talkspurt?

21
SJ95

• How does QM-120 work?
• What is QM-(600,2)? What is the motivation
  behind it?
• What is one item of future work?

22
FHPW00

• Why not TCP?
• Why TCP-Friendly?

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TFRC

• How is RTT computed?
• How is p computed?
• What is history discounting?
• What happens if the sender has no data to send?

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FHPW00

• Interpret the data
• What are the main conclusions?

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CZC02

• What is the methodology they employed to study
  UDP congestion responsiveness?
• Do they find RealVideo UDP flows are responsive
  to congestion?

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CZC02

• What are some of the cited reasons streaming
  media applications do not use TCP?
• What are the reasons CZC02 finds that streaming
  media applications do not use TCP?

27
PHH98

• What is the classification for sender-based
  repair?
• Give an example
• What is the classification of receiver-based
  repair?
• Give an example

28
PHH98

• What is Forward Error Correction (FEC)?
• What is one of the advantages of Media Dependent
  FEC?
• What is interleaving?
• What is one of the disadvantages of interleaving?
• What is noise substitution?

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PCM00

• What is fixed FEC? Why is it sub-optimal?
• What are some problems with the Bolot algorithm?
• How does the USF algorithm work?
• What methodology do they use for testing?

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PCM00
USF better
Bolot better
Interpret the above graph.
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PCM00

• Future work?

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FB00

• What is the fundamental tradeoff between error
  resilience and compression (for video)?
• Peak Signal to Noise Ratio (PSNR)
• What is it good for?
• What are some problems with it relative to
  perceived quality?

33
FB02
- Interpret the Graph
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HKBT01

• What alternate service does ABE offer?
• What is green traffic?
• What is blue traffic?

35
HKBT01

• What does it mean to say Green does not hurt
  Blue?
• Based on below formula, what happens if green
  cuts in line? How to fix?

36
HKBT01
Using DSD, what is the order of serving packets?
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HKBT01
What is the significance of this graph?
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NT02

• What are the three applications that motivate the
  classes used?
• What is the difference between HTTP 1.0 and HTTP
  1.1?
• What are the issues with TCP flows with small
  windows?

39
MJV96

• Why cant the server just use one bandwidth for
  all users in a multicast session?
• What is Layered Video?
• What is Receiver-driven about RLM?

40
MJV96

• What is shared learning?
• How does RLM scale with the number of receivers?
• How does RLM scale with the number of sessions?