Project proposal Multi-stream and multi-path audio transmission

  • 725 views
Uploaded on

 

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
725
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
10
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Multipath Routing of Multimedia Data Over Ad Hoc Wireless Networks
  • 2. Outline
    • Ad hoc wireless networks
    • Routing for ad hoc wireless networks
      • Source routing and multi-path routing
      • Example with Dynamic Source Routing (DSR)
    • Congestion optimized stream routing
      • Complete/practical solution
      • Comparison with a heuristic scheme
    • Video distortion model
    • Experimental results
      • Network congestion
      • Two applications: data download & video streaming
    • Conclusion
  • 3. Wireless Ad Hoc Networks
    • Collection of wireless nodes with no infrastructure
    • Every node can be source, destination or relay
    • Many applications : search and rescue, disaster areas…
  • 4. Ad Hoc Wireless Network Model If nodes are not limited in their transmissions, we get the following formulas :
    • Assumptions :
    • Static nodes
    • Bandwidth : 2.2 MHz
    • Interference limited network
    • Every node has global information
    15-node network
  • 5. Existing Routing Algorithms
    • Routing for wireless ad hoc networks :
      • DSDV
      • AODV
      • DSR
      • TORA
    • Optimization and routing :
      • Flow assignment
      • Resource allocation
    [Kleinrock, 1976], [Bertsekas & Gallager, 1987] [Xiao, Johansson and Boyd, 2002] [Perkins and Bhagwat, 1994] [Park and Corson, 1997] [Perkins and Royer, 1999] [Johnson and Maltz, 1996]
  • 6. DSR example
    • DSR allows to discover and maintain routes on ad hoc wireless networks
    • Example : route from node 1 to node 5
    • If no route is cached the route discovery protocol is initiated :
      • route request broadcast
      • intermediate nodes append their address and re-broadcast the reply
      • reply is sent back by the first node which knows how to reach the destination
    (1 2 10 4 5)
  • 7. Congestion Optimized Stream Routing
    • Congestion may be estimated by the average queuing delay for a packet on the network
    • Average delay over a link for the M/M/1 model :
    • So minimizing the congestion results in the following problem :
    • Subject to :
    • rate constraints at the source and destination
    • flow conservation, flow positivity
    • capacity constraints F ij +f ij < Cij
    Cross traffic F ij Optimal f ij ? i j
  • 8. Illustration Cross traffic F ij Optimal f ij ? i j Source Destination
  • 9. Solution Example
    • Streaming 100 kbps from node 1 to node 5 :
    77 16kbps 2 5 15 7 18 35 2 22 8 23 23 8 6 9 43 64 24 24
  • 10. Solution Example Example: over 3 paths 1 2 10 4 5 1 3 7 6 5 1 2 9 8 15 5
    • Properties of the solution :
      • Diversity of paths
      • Complex
      • Linear convergence
    • To lower the complexity :
      • Predetermine a set of paths
      • Optimal flow partition among the paths
      • Instantaneous convergence
    31 kbps 45 24
  • 11. Which Set of Paths ?
    • First method
      • Solve the initial problem
      • Extract the routes carrying the most traffic recursively
      • Partition over the k best
    • Practical method based on DSR :
      • Discover multiple routes through route request/reply broadcasts
      • Add the link state to the node’s address information
      • Partition over these routes
  • 12. Comparison to Load Balancing 3-path routing 6-path routing
    • Heuristic scheme for traffic partitions
      • Load balancing among bottleneck links on each path
      • Oblivious to joint links, length of path etc…
    • Solution examples
  • 13. Video Distortion Model: Encoder
    • Encoder distortion:
    • MSE measure for distortion
    • D 0 ,  and R 0 are estimated via regression
    [ Stuhlmuller 2000 ]
  • 14. Video Distortion Model: Packet Loss
    • Transmission distortion:
    • P rand is random packet loss rate
    • M/M/1 model for delay
    •  is related to coding structure
    • C is the maximum rate supported by the routes
    • T target is determined from empirical data
    Loss due to late arrival Random loss rate
  • 15. Video Distortion Model: Combined
    • Total distortion:
    • Decode video quality is limited by encoder performance at low rate, and network congestion at high rates
    Encoder MSE Trans. MSE Decoded MSE Decoded PSNR => optimal rate R* R*
  • 16. Network Simulation Setup
    • Two application scenarios
      • Data download
      • Live video streaming
    • NS-2 configuration
      • 15 static nodes, routing from node 1 to node 5
      • No random packet loss, no propagation delay
      • UDP connection, source routing
      • M/M/1 model for data and cross traffic
      • Constant Bit Rate (CBR) traffic for video
            • http:// www.isi.edu/nsnam/ns /
  • 17. Data Download Results: Congestion Traffic model: M/M/1 No. of samples: 600,000
  • 18. Video Streaming Results: Congestion Sequence : Foreman QCIF Sequence length : 250 f. Codec: H.26L TML 8.5 Frame rate : 30 fps Playout deadline : 500 ms Packetization : 1 f./packet Traffic model: CBR No. of realizations: 400 No random loss
  • 19. Video Streaming Results: End to End Delay Traffic model: CBR No. of realizations: 400 average end to end delay 90 th percentile end to end delay
  • 20. Video Streaming Results: RD Performance Sequence : Foreman QCIF Sequence length : 250 f. Codec: H.26L TML 8.5 Frame rate : 30 fps Playout deadline : 500 ms Packetization : 1 f./packet Traffic model: CBR Number of realizations: 400 Packet loss rate: 0% 6 dB 1 dB
  • 21. Video Streaming Results: Sequence Foreman QCIF Sequence 1 path 80 kbps, PSNR 32.5 dB 3 paths 187 kbps, PSNR 36.2 dB 6 paths 278 kbps, PSNR 38 dB Comparison of the operating point for different number of paths :
  • 22. Video Streaming Results: Sequence Comparison of the operating point for the heuristic and proposed schemes : 6 paths heuristic 187 kbps, PSNR 36.2 dB 6 paths optimal 278 kbps, PSNR 38 dB
  • 23. Video Streaming Results: GOP length Sequence : Foreman QCIF Sequence length : 250 f. Codec: H.26L TML 8.5 Frame rate : 30 fps Playout deadline : 350 ms Packetization : 1 f./packet Traffic model: CBR Number of realizations: 400 Packet loss rate: 1%
  • 24. Conclusions
    • Congestion optimized stream routing
      • Convex optimization formulation
      • Efficient utilization of limited bandwidth resource
      • Outperforms heuristic load balancing
    • Video distortion model
      • Combines the influence of encoder distortion with packet delay
      • Predict and compare behaviors of different coding schemes
    • Network simulation
      • Applied to data download and live video streaming
      • Demonstrated the advantage of the proposed routing scheme
      • Verified the video distortion model