video on demand
Download
Skip this Video
Download Presentation
Video On Demand

Loading in 2 Seconds...

play fullscreen
1 / 48

Video On Demand - PowerPoint PPT Presentation


  • 397 Views
  • Uploaded on

Video On Demand. Video on Demand. One video server Many video data Many clients Client want to watch at any time. Assumptions. Constant bitrate stream Perfect network transport. Unicast Solution. One channel per client No start-up latency No client buffer Low client bandwidth

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Video On Demand' - Rita


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
video on demand2
Video on Demand
  • One video server
  • Many video data
  • Many clients
  • Client want to watch at any time

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

assumptions
Assumptions
  • Constant bitrate stream
  • Perfect network transport

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

unicast solution
Unicast Solution
  • One channel per client
  • No start-up latency
  • No client buffer
  • Low client bandwidth
  • Large server bandwidth
  • Not scalable

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

multicast solution
Multicast Solution
  • Batching
    • aggregate client requests
    • serve using multicast
    • clients have to wait
    • No client buffer
    • Low client bandwidth

“Scheduling Policies for an On-Demand Video Server with Batching”

Dan, Sitaram, Shahabuddin, IBM

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

multicast solution6
Multicast Solution
  • User-centered approach
    • Scheduling data based on user requests
  • Data-centered approach
    • Don’t care about user
    • Just broadcast popular video

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

multicast solution7
Multicast Solution
  • Batching
  • Staggered Broadcast

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

staggered broadcast
Staggered Broadcast

Video

C0

C1

C2

:

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

staggered broadcast9
Staggered Broadcast
  • 2 hour video
  • 5 minutes waiting time
  • Number of channels =

2 x 60 / 5 = 24

  • Required bandwidth =

1.5Mbps x 24 = 36Mbps

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

multicast solution10
Multicast Solution
  • Batching
  • Staggered Broadcast
    • clients have to wait
    • No client buffer
    • Low client bandwidth
    • Huge server bandwidth

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

multicast solution11
Multicast Solution
  • Batching
  • Staggered Broadcast
  • Periodic Broadcast

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

periodic broadcast
Periodic Broadcast

Video

C0

C1

C2

:

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

pyramid broadcast
Pyramid Broadcast

Video

C0

C1

C2

:

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

pyramid broadcast14
Pyramid Broadcast

Video

C0

C1

C2

:

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

analysis of pyramid broadcast
Analysis of Pyramid Broadcast
  • Notations
    • B : Total available bandwidth
    • Bv : Bandwidth of video
    • Tv : Total length of each video
    • K : Number of segments per video
    • Ti : Length of segment i
    •  : Factor in geometric series

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

channel bandwidth
Channel Bandwidth

playback time = Ti

i

i+1

i+1

D’oh!

Just

miss

it!

download time = Ti+1Bv/Bi

Download time for segment i+1 needs

to be smaller than Ti for it to arrive in time.

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

channel bandwidth17
Channel Bandwidth

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

slide18
 = 2

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

start up latency
Start-up Latency
  • Worst case waiting time =

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

optimal
Optimal 

T1

2.5

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

storage requirements
Storage Requirements

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

pyramid broadcast22
Pyramid Broadcast
  • Large client bandwidth (KBv)
  • Huge client buffer (70–80% Tv)

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

permutation based pyramid broadcast
Permutation-based Pyramid Broadcast

C0

C1

C2

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

channel bandwidth24
Channel Bandwidth

playback time = Ti

i

i+1

i+1

i+1

i+1

D’oh!

Just

miss

it!

download time = Ti+1Bv/Bi

X

X needs to be smaller than Ti for segment

i+1 to arrive in time.

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

channel bandwidth25
Channel Bandwidth

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

client latency
Client Latency

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

storage requirement
Storage Requirement
  • One channel at a time
  • Can pause and wait

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

storage requirement28
Storage Requirement

pause

k-1

k-1

k

resume

k

Within time X, better

not consume all data

in buffer.

X

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

storage requirement29
Storage Requirement

pause

k-1

k-1

k

k

resume

Within time X, better

not consume all data

in buffer.

X

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

storage requirement30
Storage Requirement

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

comparisons
Comparisons

Carter, Long and Paris

“Video on Demand Broadcasting Protocols”

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

slide32

Pyramid Broadcasting

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

skyscraper broadcasting
Skyscraper Broadcasting
  • Observations:
    • storage requirement is affected by size of the largest chunk

So, let’s limit the size of the largest chunk!

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

slide34

Pyramid

Skyscraper

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

skyscraper broadcasting35
Skyscraper Broadcasting
  • Uses series

1 2 2 5 5 12 12 25 25 52 52 … W W W

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

skyscraper example
Skyscraper Example

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

skyscraper example37
Skyscraper Example

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

comparisons38
Comparisons

Carter, Long and Paris

“Video on Demand Broadcasting Protocols”

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

other schemes
Other schemes
  • Pagoda Broadcasting1 3 5 15 25 75 125 …
  • Harmonic Broadcasting

Equal segment size, varies bandwidth instead!

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

multicast solution40
Multicast Solution
  • Batching
  • Staggered Broadcast
  • Periodic Broadcast
    • Sending rate ≥ playback rate
    • May need multiple channels
    • Need additional client buffer
    • Need to wait

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

multicast solution41
Multicast Solution
  • Batching
  • Staggered Broadcast
  • Periodic Broadcast
  • Patching

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

patching
Patching

Time

mcast

unicast

Client Request

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

patching43
Patching

Patching Window: W

Time

mcast

mcast

Client Request

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

grace patching
Grace Patching

ifW < B

client buffer video[W .. end]

  • 30 minutes video
  • 1 client arrival per minute
  • Total data delivered =

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

scenario 1 b 15mins
Scenario 1: B = 15mins
  • 30 minutes video
  • 1 client arrival per minute
  • Total data delivered =

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

scenario 2 b 5mins
Scenario 2: B = 5mins
  • 30 minutes video
  • 1 client arrival per minute
  • Total data delivered =

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

scenario 3 b 2mins
Scenario 3: B = 2mins
  • 30 minutes video
  • 1 client arrival per minute
  • Total data delivered =

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

summary
Summary
  • Batching (User Centered)
  • Staggered Broadcast (Data Centered)
  • Periodic Broadcast (Data Centered)
  • Patching (True VOD)

NUS.SOC.CS5248-2010

Roger Zimmermann (based in part on slides by Ooi Wei Tsang)

ad