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 Background Source 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 scenario Resources 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 Coding PFGS: 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 control Usually 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.