Download presentation
Presentation is loading. Please wait.
Published byBernice Perry Modified over 9 years ago
1
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 3G:UMTS(384k to 2M), EDGE(384k). –More Scalable Video Coding Technology MPEG – 4 etc. –Industries: www.solidstreaming.comwww.solidstreaming.com Wide Acceptance of Video to handheld is possible!
4
Assumptions and Goals 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 Video Source Wireless Gateway Mobile
5
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.
6
INTERNET DECOUPLE THE LOSSES SEEN BY SENDER INTO WIRELESS AND WIRELINE LOSSES LEVERAGING THE KNOWLEDGE OF THE WIRELESS GATEWAY IN DETECTING CONGESTION LOSSES. DETECTING CONGESTION AND WIRELESS LOSSES
7
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 GlobalWG_count 100 101 103102 105104 KEY VARIABLES
8
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
9
Quality Control using FEC Quality controller Fair rate Loss Prob. Right amount of redundancy. Scalable Codecs: e.g. MPEG4 FEC code: fec_min_, fec_max_ Quality perceived at the receiver
10
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
11
TCP Friendly Rate Control Act on Congestion Loss only Using the approach in Floyd’s paper.
12
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_
13
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!
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.