CS590F Project: Wireless Streaming Protocol

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CS590F Project Wireless Streaming Protocol

• Xiaojun Lin
• Jitesh Nair
• Samrat Kulkarni

2
Schedule

• Introduction and motivation
• Assumptions and goals
• Techniques
• Differentiating the loss
• Quality control using FEC
• TCP-friendly rate control
• Coupling between CC and FEC
• Contributions conclusion

3
Introduction

• Background
• Proliferation of Multimedia Content
• Increasing rate of Wireless systems
• 3GUMTS(384k to 2M), EDGE(384k).
• More Scalable Video Coding Technology
• MPEG 4 etc.
• Industries www.solidstreaming.com
• Wide Acceptance of Video to handheld is possible!

4
Assumptions and Goals
Video Source

• Wired-wireless interaction
• Wireless channels is at the last hop
• Competes with other flows on the internet
• Wireless loss at the last hop

Internet
Wireless Gateway
wireless
Mobile
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Objective

• Our Wireless Streaming Protocol will
• Maximize perceived quality at the receiver given
  network conditions.
• Live Friendly with TCP on wired Internet
• Responsive to changing network conditions.

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DETECTING CONGESTION AND WIRELESS LOSSES
CONGESTION LOSS
SENDER
WIRELESS GATEWAY
INTERNET
WIRE LESS LOSS

• DECOUPLE THE LOSSES SEEN BY SENDER INTO WIRELESS
  AND WIRELINE LOSSES
• LEVERAGING THE KNOWLEDGE OF THE WIRELESS GATEWAY
  IN DETECTING CONGESTION LOSSES.

RECIEVER
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KEY VARIABLES
GLOBAL_SEQUENCE_ This is a non negative
monotonically increasing number. Each packet has
a unique GLOBAL_SEQUENCE_ number. WG_COUNT_ This
is a non negative monotonically increasing number
set by the wireless gateway.
DIFFERENCE IN THE VALUE OF THE GLOBAL_SEQUENCE_
AND WG_COUNT_ INDICATES A CONGESTION
LOSS DIFFERENCE IN THE VALUE OF THE WG_COUNT_
AND THE NET PACKETS RECEIVED AT THE RECIEVER
INDICATES THE WIRLESS LOSS
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Packet Format

• From Sender
• GLOBAL_SEQUENCE_
• WG_COUNT_
• For each block block indicates a chunk of data
  which is packetized. This is in the FEC scheme.
  (think of GOP).
• FEC_MAX_ block size
• FEC_MIN_ minimum number of packet required to
  decode.
• LOCAL_SEQUENCE_ This is a non negative
  monotonically increasing number. Each packet in a
  block has a unique local sequence number.
• From Receiver
• PACKETS_EXPECTED
• CONGESTION_LOSS
• WIRELESS_LOSS

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Quality Control using FEC
Quality controller
Fair rate
Right amount of redundancy.
Loss Prob.

• Scalable Codecs e.g. MPEG4
• FEC code fec_min_, fec_max_
• Quality perceived at the receiver

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Quality Control using FEC

• Model for perceived quality at the receiver
• Let m be the number of packets arrived at the
  receiver
• Maximize expected quality over fec_min_
• subject to

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TCP Friendly Rate Control

• Act on Congestion Loss only
• Using the approach in Floyds paper.

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The Whole Picture

• Sender send out FEC-coded stream.
• Receiver collect statistics related to congestion
  loss and wireless loss
• At the sender
• Congestion loss ? raw rate
• Raw rate loss ? redundancy, layer, net_rate
• Raw rate net_rate fec_max_ / fec_min_

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Contribution and Conclusion

• Combined Source/Channel Coding for transmitting
  multimedia to wireless terminals.
• require assistance at the wireless
  gateway/basestation to detect different source of
  losses.
• First step towards multimedia to your hand!