Distributed%20Multimedia%20Streaming%20over%20Peer-to-Peer%20Network

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Distributed Multimedia Streaming over
Peer-to-Peer Network

• Jin B. Kwon, Heon Y. Yeom

Euro-Par 2003, 9th International Conference on
Parallel and Distributed Computing, August 2003,
(Klagenfurt, Austria) (Also published in LNCS
2790, Euro-Par 2003 Parallel Processing, pp.
851-858)
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Agenda

• Introduction
• Definitions and assumptions
• Transmission Scheduling
• Fast Distribution
• Simulations and Performance Studies
• Conclusion

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Introduction

• Existing multimedia streaming
• Client-sever model
• -gt server network bandwidth limitations
• Possible solutions
• Multicast
• -gtscalability
• Peer-to-Peer model
• -gtin early stage

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Introduction

• The authors focus on
• 1)Transmission scheduling of the media data for a
  multi-supplier P2P streaming session
• Supplying peers with heterogeneous out-bound
  bandwidth
• The problem is to schedule the segments of media
  data so as to minimize the buffering delay
• Propose Fixed-length slotted scheduling (FSS),
  better than OTS.

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Introduction

• The authors focus on
• 2)Fast distribution of media contents
• P2P system is self-growing.
• Important to convert requesting peer to supplying
  peers as soon as possible
• Propose FAST aims at accelerating the speed at
  which the P2P system capacity increases

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Definitions

• Candidate Set Set of supplying peers
• Requesting peer
• selects the supplying peers from the set,
• opens a channel with each selected supplying
  peer,
• requests the data segment from them according to
  a scheduling mechanism
• After receiving, stores and becomes a candidate
  of the media content

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Assumptions

• Appropriate searching algorithm
• ? playback rate of the media data
• Pr requesting peer
• Rin(r) in-bound bandwidth Pr
• Rout(r) out-bound bandwidth Pr
• 0 lt Rin(r) ? Rout gt 0
• buffering delay

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Transmission Schedule

• The goal minimize buffering delay while ensure
  continuous playback
• Determine the data segments to be transmitted
  over each channel and the transmission order of
  the segments.

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p(t) Amount of data being played for t seconds since beginning of playback
d(t) Amount of consecutive data from the beginning of the media file received for t seconds

• To ensure continuous playback

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OTS

• Consider 4 channels with bandwidth of

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Fixed Length Slotted Scheduling (FSS)

• Variable-length segments are assigned to the
  channels in round-robin fashion
• Define slot length w
• i-th channel bandwidth Bi
• segment length wBi
• Use previous example,

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Fixed Length Slotted Scheduling (FSS)

• notice the overhead transmission!

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Fast Distribution - definition

• Requesting Peer
• Candidate Peer
• Mature Peer holding the whole media file
• Immature Peer being download the media data

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Fast Distribution

• Xi(t, r) when Pi is assumed to be selected as
  a supplying peer of a request peer Pr, the
  position within the media file of the data to be
  requested to transmit at t.

Rate of increase
For a immature peer to be a supplying peer of Pr
(called semi-mature peer)
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Fast Distribution

• Xi(t, r) can not be determined until Pr select
  its supplying peers
• use upper bound function xr(t)

However, not satisfying it does not mean that Pi
is not a semi-mature peer
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Peer requesting video procedure

• Select from mature and semi-mature peers
• Since FSS depends on B1, the maximum outbound
  bandwidth peer will be chosen. The procedure is
  repeated until B(r) Rin(r)

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Peer requesting video procedure

• If the P2P system is beyond capacity
• Start download with the acquired channels and
  buffering (FAST1)
• Withdraw the request and retry after a randomized
  second.(FAST2)
• Start download with the acquired channels and
  retry to acquire the remainder after T
  minutes.(FAST3)

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Simulation

• Parameters
• 50,100 peers, 100 seed peers initial
• Request arrival rate follows Poisson distribution
  with mean 1/T
• Video length 60min
• Inbound bandwidth ?
• Outbound bandwidth
• Seed peers ?/2
• Others ?/2, ?/4, ?/8 ?/16 10, 10, 40, 40

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Performance Study

• Assume
• Channel bandwidth has one of ?/2, ?/4, ?/8 ?/16
  ?/2n
• B(r) ?
• Time to transmit a segment

gt
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Conclusion

• Variable length segment for Transmission
  Scheduling FSS
• Define semi-mature peer for fast Distribution
• Performance evaluation over OTS and FSS

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End