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Efficient Transmission of Rendering-Related Data Using the NIProxy
Efficient Transmission of Rendering-Related Data Using the NIProxy
Maarten WijnantsTom JehaesPeter Quax
Wim LamotteHasselt University - Expertise Centre for Digital Media
Efficient Transmission of Rendering-Related Data Using the NIProxy
Outline
• Introduction & Motivation• Network Intelligence Proxy (NIProxy)
– Client Bandwidth Management
• Considered Networked Application– Rendering Scheme
• Implementation• Evaluation
– Experimental Results– Discussion
• Conclusions
18/03/2008 EuroIMSA2008 2
Efficient Transmission of Rendering-Related Data Using the NIProxy
Introduction & Motivation
• Client downstream bandwidth == scarce commodity– May not suffice to receive all data produced by
networked applications==> Should be managed judiciously==> Goal = Optimize usage experience
• Client bandwidth management approaches– Directly integrated in application software
• Unprofitable from economic point of view
– Generic/reusable middleware solution• “Network Intelligence Proxy” (NIProxy)
18/03/2008 EuroIMSA2008 3
Efficient Transmission of Rendering-Related Data Using the NIProxy
Network Intelligence Proxy
• Network intermediary (proxy server)• Objective = Maximize user Quality of
Experience (QoE) (note: QoE != QoS)• Approach = Incorporation of context in
transportation network– Both network and application awareness
• Context is exploited to improve data dissemination to clients– Automatic and dynamic traffic management– Multimedia service provision
18/03/2008 EuroIMSA2008 4
Efficient Transmission of Rendering-Related Data Using the NIProxy
Client Bandwidth Management using NIProxy
• Organization of network flows in stream hierarchy– Tree-like structure– Internal nodes : Implement BW distribution
• Priority• WeightData• WeightStream• Percentage
– Leaf nodes : Correspond to actual network flow• Real-time : Toggle between discrete BW usage levels• Non real-time : Continuous BW usage adaptation
18/03/2008 EuroIMSA2008 5
Efficient Transmission of Rendering-Related Data Using the NIProxy
Considered Networked Application
• 3D Networked Virtual Environment (NVE)• User communication : Audio & video chat• Advanced rendering scheme
– Combines geometric & image-based rendering• Geometric rendering: Progressive Meshes (PMs)
– Enables progressive transmission• IBR: Relief Texture Mapped Objects (RTMOs)
– Images with depth-information• In terms of visual quality : geom rendering > IBR• In terms of complexity: geom rendering > IBR
18/03/2008 EuroIMSA2008 6
Efficient Transmission of Rendering-Related Data Using the NIProxy
Considered Networked Application
• Advanced rendering scheme (continued)– Level of Detail (LoD) manager
• Selects most suitable representation for 3D objects• Considers scene priority, framerate (current/desired),
distance to viewer (= model display size), …• Approach : PM for nearby, IBR for distant objects
– Model representation switching is supported• All rendering-related data managed by file
server (maintains central model database)– Dissemination of model data to clients needed
• Objective = quickly present user with initial view • In terms of size: geom data > IBR data
18/03/2008 EuroIMSA2008 7
Efficient Transmission of Rendering-Related Data Using the NIProxy
Implementation
18/03/2008
• Translate requirements into appropriate stream hierarchy structure
EuroIMSA2008 8
Efficient Transmission of Rendering-Related Data Using the NIProxy
Implementation
18/03/2008
• Translate requirements into appropriate stream hierarchy structure
EuroIMSA2008 9
Efficient Transmission of Rendering-Related Data Using the NIProxy
Implementation
18/03/2008
• Translate requirements into appropriate stream hierarchy structure
EuroIMSA2008 10
Efficient Transmission of Rendering-Related Data Using the NIProxy
Implementation
18/03/2008
• Translate requirements into appropriate stream hierarchy structure
EuroIMSA2008 11
Efficient Transmission of Rendering-Related Data Using the NIProxy
EvaluationMinimalist Experiment
18/03/2008
• Limited model count & no real-time traffic• Limited client downstream BW (20KBps)
EuroIMSA2008 12
Efficient Transmission of Rendering-Related Data Using the NIProxy
EvaluationMinimalist Experiment
18/03/2008
• Limited model count & no real-time traffic• Limited client downstream BW (20KBps)
EuroIMSA2008 13
Efficient Transmission of Rendering-Related Data Using the NIProxy
EvaluationRealistic Experiment
18/03/2008
• Densely populated scene, common BW limit (100 KBps), contention from real-time traffic
EuroIMSA2008 14
IBR pre-loading Video trafficContention 3D tx finishedIBRGeometry
Efficient Transmission of Rendering-Related Data Using the NIProxy
EvaluationFindings & Discussion
• Over-encumbrance of client's network connection at all times prevented– Minimal packet delay and loss– Optimal data reception at client-side
• NVE requirements captured successfully– Minimize time needed for rendering initial view
• First stream image-based representation• Upgrade gradually with geometric data
• Contention for client BW coped with– Through use Percentage hierarchy node
18/03/2008 EuroIMSA2008 15
==> User QoE improved
Efficient Transmission of Rendering-Related Data Using the NIProxy
Conclusions
• Client bandwidth remains scarce and hence requires efficient management
• NIProxy : Network Intelligence Proxy– Awareness introduction in network
• NIProxy integration in NVE application– Distribution of rendering-related data– Real-time streaming audiovisual content
• Exp results show NVE requirements were translated to effective BW distributions– Outcome = Improved user QoE
18/03/2008 EuroIMSA2008 16
Efficient Transmission of Rendering-Related Data Using the NIProxy
Thank you for your attention!Any questions?