an adaptive video multicast scheme for varying workloads
Download
Skip this Video
Download Presentation
An adaptive video multicast scheme for varying workloads

Loading in 2 Seconds...

play fullscreen
1 / 29

An adaptive video multicast scheme for varying workloads - PowerPoint PPT Presentation


  • 101 Views
  • Uploaded on

An adaptive video multicast scheme for varying workloads. Kien A.Hua, JungHwan Oh, Khanh Vu Multimedia Systems, Springer-Verlag 2002. Outline. Introduction Related Work Proposed Approach Performance Model Performance Conclusion. Introduction.

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 ' An adaptive video multicast scheme for varying workloads' - cybill


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
an adaptive video multicast scheme for varying workloads

An adaptive video multicast scheme for varying workloads

Kien A.Hua, JungHwan Oh, Khanh Vu

Multimedia Systems, Springer-Verlag 2002

outline
Outline
  • Introduction
  • Related Work
  • Proposed Approach
  • Performance Model
  • Performance
  • Conclusion
introduction
Introduction
  • Maximize the efficiency of server resource with
    • Periodic broadcast
    • Scheduled Multicast (batching)
    • Hybrid Design
  • Will show that existing scheduled multicast techniques are not suited for hybrid designs
related work skyscraper broadcasting scheme
Related WorkSkyscraper Broadcasting Scheme
  • Fragmentation recursive function
    • Series [1,2,2,5,5,12,12,25,25,52,52,…]
related work skyscraper broadcasting scheme1
Related WorkSkyscraper Broadcasting Scheme

22-mins video

5 min buffer

Apply aforementioned series function => segment size = 10.4 !!

1.5 Mbits/sec

0.5 min latency

related work scheduled multicast
Related Work Scheduled Multicast
  • Differ primarily in the criterion used to select which batch will receive service
    • First come, first served (FCFS)
    • Maximum queue length first (MQL)
    • Maximum factored queue length first (MFQ)
related work scheduled multicast1
Related Work Scheduled Multicast
  • FCFS
  • MQL

Video 1

time

Video 2

time

Fair , maybe bad throughput

Video 1

time

time

Video 2

Better throughput, maybe not fair

related work maximum factored queue length first mfq
Related WorkMaximum factored queue length first (MFQ)
  • Applying a discriminatory weighting factor to the length of the queue
  • : video i length, : the request frequency of video i
  • Schedule video with the largest value of
related work maximum factored queue length first mfq1
Related WorkMaximum factored queue length first (MFQ)
  • d
  • d

Still not fair, because not average waiting time !!

proposed approach
Proposed Approach
  • Adaptive Hybrid Approach (AHA)
    • With a novel scheduled multicast --

“Largest aggregated waiting time first scheme” (LAW)

    • And SB (skyscraper broadcast)
slide12

: the total number of pending requests for video i

: the arrival time of the jth request for video i

c : the current time

LAW
  • Compare with MQL, it take account of the distribution of the request
    • With considering “aggregated waiting time”
slide13
LAW

Compute the sum of video i service latency

S1=128*5-(107+111+115+121+126)=60

S1=128*5-(107+111+115+121+126)=60

S2=128*4-(112+119+122+127)=32

adaptive hybrid approach
Adaptive hybrid approach
  • With following procedures to decide which videos to broadcast
performance model
Performance model
  • Compare AHA with MFQ-SB-n
  • Performance metrics
    • Defection rate
    • Unfairness
    • Average service latency
    • Throughput
  • 100 videos, each 120 mins,

avg. playback rate 1.5 Mbits/sec.

performance law vs mfq
Performance - LAW vs. MFQ

LAW perform slightly

better than MFQ

in service latency,

throughput, defection rate

Arrival rate : 8 req/min

Skew factor : 0.3

performance1
Performance
  • Compare MFQ-SB-n with altering one of
    • Server Capacity (channels)
    • Request Arrival Rate
    • Skew Factor
conclusion
Conclusion
  • Prove that existing scheduled multicast schemes are not suited for hybrid design
  • Proposed a new technique called Largest Aggregated Waiting time first (LAW)
  • AHA is capable of coping with a changing workload
periodic broadcast 1996
Periodic Broadcast (1996)
  • PB v.s. batch:
    • Short initial delay
    • Large client-side buffer

video

Client requests

time

batching 1993
Batching (1993)
  • Batch window:
    • The time interval to initiate a batch stream.

0

t1

t2

t3

time

Client requests

ad