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Quality-Driven Cross-Layer Optimized Video Delivery over LTE. IEEE Communications Magazine , FEB 2010 Speaker: 劉姿瑾 Date: 25, JUL 2012. Outline . Introduction Objective System Overview Cross-Layer Optimized System Dynamic Resource Allocation - WRR Experimental Analysis Conclusions
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Quality-Driven Cross-Layer Optimized Video Delivery over LTE IEEE Communications Magazine, FEB 2010 Speaker: 劉姿瑾 Date: 25, JUL 2012
Outline • Introduction • Objective • System Overview • Cross-Layer Optimized System • Dynamic Resource Allocation - WRR • Experimental Analysis • Conclusions • References
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.
Objective Under given QoS constraints, dynamically allocating resources and choosing system parameters to: Maximize system throughput. Achieve scheduling fairness.
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
Dynamic resource allocation - WRR • WRR – Weighted Round-Robin Scheduling Algorithm: • Channel quality • Packet delay constraint • Historical average data rate • To overcome: • Distortion • Throughput • Fairness
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
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.
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.
References HaiyanLuo; Song Ci; Dalei Wu; Jianjun Wu; HuiTang, “Quality-driven cross-layer optimized video delivery over LTE,” Communications Magazine, IEEE, 2010 , Page(s): 102 - 109