Differentiated Quality Video Delivery in Overlay Multicasting Environment

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Differentiated Quality Video Delivery in Overlay
Multicasting Environment

• Ying Qiao
• Carleton University
• Project Presentation at the class
• Quality of Service Management for Multimedia
  Applications
• Provided by Professor Bochmann

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Outline

• Introduction
• -- Internet multimedia delivery
• -- Types of Video service
• -- multimedia multicast
• Overlay multicast environment
• -- Video coding
• -- Video delivery
• Layered Peer-to-Peer Streaming
• Supporting Large-Scale Live Streaming
  Applications with Dynamic Application End-Points
• Incentive mechanism for Peer-to-Peer Media
  Streaming
• Conclusion

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Introduction (1)

• Internet media delivery
• Types of Video Service
• -- No VOD
• -- Pay-Per-view
• -- True VOD
• -- Near VOD (NVOD)
• -- Quasi-VOD (QVOD)
• Basic multicast functionality
• -- Group membership management
• -- Data delivery path maintenance
• -- Replication and forwarding

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Introduction (2)

• Internet media multicast
• IP multicast
• Overlay multicast

Ref 4
5
Overlay Multicasting Environment (1)

• Resources provided by peer end node
• -- Network bandwidth
• -- Storage space
• -- CPU power
• Features
• -- Overlay Multicast is deployed with the
  basic uni-cast routing infrastructure
• -- End hosts only maintain state for the
  groups they are participating in

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Overlay Multicasting Environment (2)

• Three architectures
• -- Dedicated-Infrastructure
• -- Application-Endpoint
• -- Waypoint

Ref 4
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Overlay Multicasting Environment (3)

• Video Coding
• -- Replicated streaming
• -- Layered streaming
• -- Multiple Description Coding

Ref 1
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Overlay Multicasting Environment (4)

• Video Delivery tree
• -- Single tree
• -- Multiple tree

ZIGZAG Ref 5
SplitStream Ref 6
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Overlay Multicasting Environment (5)

• Challenge for overlay multicast
• -- Bandwidth constraints
• -- Receiver scalability
• -- Network dynamics
• -- Receiver heterogeneity

Ref 4
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Layered Peer-to-Peer Streaming (1)

• Layered video Ref 2
• -- Video is encoded into one base layer and
  multiple enhancement layers
• -- The base layer can be decoded
  independently
• -- The enhancement layers can be decoded
  cumulatively
• Network heterogeneity
• Ref 3

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Layered Peer-to-Peer Streaming (2)

• Large-scale on-demand multimedia distribution
• -- Asynchrony of user requests
• -- Heterogeneity of client resource
  capabilities
• Layered Peer-to-Peer Streaming
• -- Cache-and-relay
• -- Layer-encoded streaming

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Layered Peer-to-Peer Streaming (3)

• Layered Peer-to-Peer Streaming
• -- Cache-and-relay
• -- Layer-encoded streaming
• Goal
• -- Maximize the number of the received
  streams from end nodes other than the source
• -- Subject to
• (1) number of received streams for one
  receiver lt inbound bandwidth of the receiver
• (2) total number of received streaming
  from one sender lt outbound bandwidth of the
  sender

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Basic Algorithm

• Receiver k, inbound bandwidth
• a set of the hosts qualified as
  the supplying peers of and sorted the Hosts
  with the available layers
• Arranging the layers from the beginning of S

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Performance Evaluation (1)

• Request composition
• -- Modem/ISDN peers, 50, 112kbps
• -- Cable Modem/DSL peers, 35, 1Mbps
• -- Ethernet Peers, 15, 10Mbps
• Quality satisfaction
• -- The ratio of received quality and expected
  quality of a peer
• Result
• --The layered approach is able to fully
  utilize the marginal outbound bandwidth of
  supplying peer, and more adapted to the bandwidth
  asymmetric

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Performance Evaluation (2)

• Longer buffer enables a supplying peer to help
  more later-coming peers by prolonging the
  supplying chain
• Further increasing buffer size has very little
  help at prolonging the supplying chain

• Request chain (tree) in both cases
• Layered approach relieves the server bandwidth
  request with peer bandwidth

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Fairness

• Outbound/inbound lt 1
• Outbound/inbound gt1

• 40 Ethernet Peers are not fully satisfied
• Reason the limiting inbound of the Modem/ISDN,
  and Cable Modem/DSL peers can not satisfied the
  Ethernet Peers

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Robustness

• Robustness
• -- 50 of the supplying peers depart early
  before the playback is finished
• -- Reconfiguration through buffer
• -- Failure ratio is the percentage of failed
  peers among all departure peers

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Conclusion for the layered Peer-To-Peer Streaming

• Be optimal at maximizing the streaming quality of
  heterogeneous peers
• Be scalable at saving server bandwidth
• Be efficient at utilizing bandwidth resource of
  supplying peers
• Evaluation
• -- Whether establishing fairness among peers,
  in terms of streaming quality satisfaction and
  bandwidth contribution
• -- Whether being robust against unexpected peer
  departures/failures

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Supporting Large-Scale Live Streaming
Applications

• Key requirements
• -- Resource constraints
• -- Stability
• -- Efficient overlay structure
• Live Streaming Workload
• -- Large scale the peak group size is 1,000
  to 80,000 hosts
• -- A large number of short participations
• -- Heavy tail with some very long
  participations

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Bandwidth Resource Constraints

• Single Tree Protocols
• -- Resource Index
• -- Trace study shows sufficient bandwidth
  resource
• Multiple Tree Protocol
• -- Increase the overall resilience
• -- Tightly coupled with specialized video
  encoding
• -- Resource Index SupplyOfBW/DemandOfBW
• -- Increase the supply of the resources

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Stability (1)

• Metrics
• -- Mean interval between ancestor change for
  each participation -- Number of descendants
  of a departing participation
• Simulation of single tree
• -- Host join asks the source to get m
  current group members, picks one host as parent
• -- Host leave all of its descendants pick
  one host
• -- Parent Selection Algorithms Oracle
  Longest-First Minimum depth Random
  
• Simulation Results
• -- Oracle is the best
• -- Minimum depth tree can provide good
  performance

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Stability (2)

• Simulation Results
• -- Oracle is the best
• -- Minimum depth tree can provide good
  performance

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Stability (3)

• Impact of Multiple-Tree Protocols
• -- Independent trees
• -- Load balancing
• -- Preemption
• Simulation result
• -- More frequent ancestor changes
• -- Improved performance comes at a cost of
  more frequents disconnects, more protocol
  overhead, and more complex protocols

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Efficient overlay structure (1)

• Overlay structure closely reflects the underlying
  IP network
• -- Need to discover other nearby hosts as
  parents
• -- Partition hosts into clusters
• -- One member of each cluster is designated
  as the clustered head
• -- Hosts in the same cluster maintain
  knowledge about one another
• Clustering Quality Metric
• -- Average and maximum intra-cluster distance
  in milliseconds

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Efficient overlay structure (2)

• Sensitivity to Number of Clusters
• -- More clusters smaller intra-cluster
  distance
• -- Maximum intra-cluster distance more
  sensitive to the change of number of clusters

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Efficient overlay structure (3)

• Sensitivity to Cluster Size and Resource
  Maintenance
• -- Bounding the cluster size doesnt
  significantly affect the intra-cluster distances

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Conclusion for large-scale live streaming
applications with dynamic application end-points

• Minimizing depth in single-tree protocols
  provides good stability performance
• Multiple-tree protocols can significantly improve
  the quality of streams
• Simple clustering techniques improve the
  efficiency of the overlay structure
• Opening issue encourage application end-points
  to contribute their resources is an important
  direction

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Incentive Mechanism for Peer-to-Peer Media
Streaming (1)
System quality is T is the total number of
the packets in a streaming session, is 1 if
the packet i arrives at the receiver before its
scheduled play-out time, and 0 otherwise
Cooperation brings quality
Simultaneous uploading hurts quality
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Incentive Mechanism for Peer-to-Peer Media
Streaming (2)

• Random peer selection provides random quality

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Score-based incentive mechanism

• Peer selection scheme allows a user to select
  peers with equal or lower rank to serve as
  suppliers
• A user wishes to receive better-than-best-effort
  streaming, it must earn a positive score by
  contributing to the system
• The stream quality for a receiver can be
  expressed as a function of contribution, score,
  or rank

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Functions
Scoring function could be
Contribution cost
Rank Computation
Quality function
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Experiment system
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Performance evaluation

• Packets the miss their play-out deadlines are
  considered as lost

• Expected rate the total bytes coming from all
  senders
• The gain increases for the incentive when the K
  increases
• When kgt20, the difference of the rates decreases
  because the bottleneck is shifted from the hosts
  to the network

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Quality of Streaming
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Conclusion for incentive mechanism for
Peer-to-Peer Media Streaming

• Motivation
• -- The stream quality is poor if the level of
  cooperation is low
• -- Cooperation from a few altruistic users
  cannot provide high quality streaming to its
  users in a large system
• Conclusion
• -- A rank-based incentive mechanism achieves
  cooperation through service differentiation
• -- The contribution of a user is converted into
  a score, then the score is mapped into a rank,
  and the rank provides flexibility in peer
  selection that determines the quality of a
  streaming session
• -- Cooperative users earn higher rank by
  contributing their resources to others, and
  eventually receive high quality streaming

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Conclusion

• Application layer multicasting
• Consuming the other end nodes resource while
  sharing own resource out
• The differentiated quality is realized with
  replicated streaming, layered streaming, and MDC
• Replicated streaming is used at the single tree
  delivery
• In the single tree, the minimize depth algorithm
  shows good performance
• Layered Streaming and MDC with multiple tree
  delivery increases resource, and improve the
  stability as well
• Cluster can improve the efficiency of the overlay
  structure
• Fairness is still an open issue
• Incentive mechanism is a solution to encouraging
  resource sharing

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Reference

• 1 Layered Peer-to-Peer Streaming
• 2 A Comparison of Layering and Stream
  Replication Video Multicast Schemes
• 3 Receiver-Driver layered Multicast
• 4 Internet Multicast Video Delivery
• 5 ZIGZAG An Efficient Peer-to-Peer Scheme for
  Media Streaming
• 6 SplitStream High-bandwidth content
  distribution in cooperative environment
• 7 The Feasibility of Supporting Large-Scale
  Live Streaming Applications with Dynamic
  Application End-Points
• 8 Incentive Mechanism for Peer-to-Peer Media
  Streaming

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Appendix Receiver-Driven Layered Multicast

• Rate-adaptation protocol
• Each receiver runs the control loop
• -- On congestion, drop a layer
• -- On spare capacity, add a layer
• Join-experiment
• -- adding layers at well-chosen times
• -- causing congestion, then the receiver
  drops the adding layers
• -- successful, the receiver start adding
  another join-experiment
• Exponential Join timer for RLM adaptation at the
  join experiment
• Sharing learning in multiple receivers for
  scaling of the receiver