quality-driven cross-layer optimized video delivery over lte

Copyright © 2011, MBL@CS.NCTU

Quality-Driven Cross-Layer Optimized Video Delivery over LTE

IEEE Communications Magazine, FEB 2010Speaker: 劉姿瑾

Date: 25, JUL 2012

Copyright © 2011, MBL@CS.NCTU

Outline

• Introduction• Objective• System Overview

– Cross-Layer Optimized System– Dynamic Resource Allocation - WRR

• Experimental Analysis• Conclusions• References

Copyright © 2011, MBL@CS.NCTU

Introduction

• Application-oriented QoS for video delivery have been largely ignored.

• Higher data rate could lead to higher packet loss rate– Degrading the user-perceived video quality.

• A new QoS-aware LTE OFDMA scheduling algorithm: – LTE downlink– Real-time video– Best user-perceived video quality – Under the given application delay constraint.

• A cross-layer system to optimize video delivery.

Copyright © 2011, MBL@CS.NCTU

Objective

• Under given QoS constraints, dynamically allocating resources and choosing system parameters to:

• Maximize system throughput.• Achieve scheduling fairness.

Copyright © 2011, MBL@CS.NCTU

System Overview

• Cross-layer optimized video delivery system:– Dynamic resource allocation

• WRR – Weighted Round-Robin Scheduling Algorithm

– Video application• Video encoding

– Wireless delivery• Channel quality feedback

– Cross-layer optimization• Best MCS – Modulation and Coding Scheme• Encoder parameters

Copyright © 2011, MBL@CS.NCTU

Cross-Layer Optimized System

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Dynamic resource allocation - WRR

• WRR – Weighted Round-Robin Scheduling Algorithm:– Channel quality – Packet delay constraint– Historical average data rate

• To overcome:– Distortion– Throughput – Fairness

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Dynamic resource allocation – WRR (2)

• Channel quality (positive)– – The maximum available channel rate.

• Channel quality presenting by SNR – Signal to Noise Ratio.• The larger the available channel rate, the higher the need to

assign this resource block to the user.• Packet delay constraint (negative)

– – The maximum delay constraint.• - QoS delay constraint for user n at any resource allocation

period.• Historical average data rate (negative)

– – The maximum historical average data rate.• The average data rate of this user on a given resource block

within a given time window .• Wider : Fairness-oriented• Smaller : Throughput-oriented

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Dynamic resource allocation – WRR (3)

• Weighting the user against all the available resource blocks in the current OFDM frame.– Resource Block (RB): The unit of allocating

resource.– : The total available RBs of a given OFDM frame.

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Dynamic resource allocation – WRR (4)

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Dynamic resource allocation – WRR (5)

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Experimental Analysis

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Conclusions

• An extended QoS-aware OFDMA scheduling algorithm has been proposed.– System throughput– Application QoS– Scheduling fairness

• A cross-layer optimized system has been presented.– Achieve the best user-perceived video quality – Dynamically adapting to the instantaneous

channel quality.

Copyright © 2011, MBL@CS.NCTU

References

• Haiyan Luo; Song Ci; Dalei Wu; Jianjun Wu; Hui Tang, “Quality-driven cross-layer optimized video delivery over LTE,” Communications Magazine, IEEE, 2010 , Page(s): 102 - 109