Robust Scalable Video Streaming over Internet with Network-Adaptive

Congestion Control and Unequal Loss Protection

Quan Zang, Guijin Wang, Wenwu Zhu, and Ya-Qin Zang

International workshop for Packet Video, April 2001

Outline

Introduction

BackgroundSource Coding – Scalable Video Coding

Channel Coding – Reed-Solomon Code

End-to-End Architecture

Network-Adaptive Congestion Control

Network-Adaptive ULP

Simulation Result

Conclusion

Introduction

Video over Internet with QoS guarantee faces many challenges due to network bandwidth fluctuation, packet loss, and delay.

From end-to-end application-level QoS adaptation

Two main issues in video streaming scenarioResources for an end-to-end application should utilize

How to cope with the packet loss as well as the varying network condition

Background-Source Coding

Scalable Video CodingPFGS: Progressive Fine Granular Scalable

Base Layer

1st Layer

2nd Layer

3rd Layer

PFGS - Simulation Result

About 0.5dB gain

Background - Channel Coding

The idea of FEC across packet is to transmit redundant packets that can be used in the receiver to reconstruct lost packets

Use Reed-Solomon code for FEC

An RS code is defined RS(n ,k)Can correct t = (n-k)/2 symbol errors

Can correct t = n-k symbol erasure

n

k

End-to-End Architecture

End-to-End Architecture (cont.)

The Key components : MSTFP bandwidth estimation, MSTFP congestion control, ULP channel coding, target bit allocation

MSTFP bandwidth estimation use the data from Network Monitor module

Four stage:• Estimating packet loss ratio

• Estimating round trip time

• Estimating available network bandwidth

• Adjusting sending rate

Congestion Control

Network-adaptive congestion controlUsually TCP congestion control is based on Additive Increase / Multiplicative Decrease (AIMD)

Instead of using AIMD directly, they adjust the transmission rate related to packet loss ratio

Increment in transmission rate

Slight reduction in the transmission rate

Aggressive reduction in the transmission rate

Network-adaptive ULP

When the network is in good condition , more bits are allocated for source coding and fewer bits are allocated for channel coding

The layered coding framework is suited for prioritized transmission

Unequal Loss Protection are used that protects different layers using different FEC

Fixed Length Packetization

data packet

redundant packet

k information packets

n-k redundant packets

PacketLen1

Largest data packet size of layer i

redundant packet

data packet

k information packets

n-k redundant packets

PacketLen2

Stuffing

Unequal Interleaving and Packetization

Unequal Interleaving and Packetization (cont.)

LC (Loss Control) Header

Simulation Result (1)

Simulation Result (1) (cont.)

The higher bandwidth , the more efficient their scheme with the other two fixed ULP scheme

The better the channel condition is, the smaller difference between their scheme and ULP schemes

Simulation Result (2)

Simulation Result (3)

Conclusion

A new network-adaptive congestion scheme with unequal loss protection , unequal interleaving for scalable video streaming over the Internet.

An End-to-End architecture is proposed to simultaneously address the congestion control, error control, and packetization.