Presentation on theme: "国立大学法人 奈良先端科学技術大学院大学 QoS Adaptation for Realizing Interaction between Virtual and Real Worlds in Pervasive Network Environment Shinya."— Presentation transcript:
国立大学法人 奈良先端科学技術大学院大学 http://www.naist.jp/ QoS Adaptation for Realizing Interaction between Virtual and Real Worlds in Pervasive Network Environment Shinya Yamamoto ， Yoshihiro Murata ， Naoki Shibata * ， Keiichi Yasumoto and Minoru Ito Shinya Yamamoto ， Yoshihiro Murata ， Naoki Shibata * ， Keiichi Yasumoto and Minoru Ito Nara Institute of Science and Technology * Shiga University
2007/06/05NOSSDAV 20072 Overview Objective Enabling “space sharing” between virtual and real world users using ordinary devices and networks We propose a framework FAIRVIEW Reflects changes in real space to virtual space, and vice versa Enables realistic 3D information sharing for CSCW usage Only requires ordinary devices/networks
2007/06/05NOSSDAV 20074 Related work Many studies for sharing virtual objects, as if they were in front of users –Mixed Reality (MR)/Augmented Reality (AR) –Computer Supported Cooperative Work (CSCW) These techniques require –Expensive and special devices –Dedicated networks and servers We want to realize similar object sharing at low cost Create virtual building http://artis.imag.fr/Members/Raphael. Grasset/
2007/06/05NOSSDAV 20076 Target environment Realizing a framework for large number of real and virtual users to share information via network –Applications: such as concert, shopping, exhibition, sports, game, etc… We propose FAIRVIEW △ is trade-off Sharing objects between real and virtual worlds can be realized using Mixed Reality techniques. MR allows real world users to view virtual objects at high quality by overlapping them to their views. MR also allows virtual world users to view real objects by measuring and reflecting shape/orientation.
2007/06/05NOSSDAV 20077 Target environment Realizing a framework for large number of real and virtual users to share information via network –Applications: such as concert, shopping, exhibition, sports, game, etc… We propose FAIRVIEW △ is trade-off NVEs enable virtual object sharing scalably and at low cost. There is a trade-off between object quality and scalability/cost. Most NVEs do not support real object sharing.
2007/06/05NOSSDAV 20078 Target environment Realizing a framework for large number of real and virtual users to share information via network –Applications: such as concert, shopping, exhibition, sports, game, etc… We propose FAIRVIEW △ is trade-off FAIRVIEW satisfies all of these criteria.
2007/06/05NOSSDAV 200710 User equipment PDA 3D sensors HMD Web Cam Real userVirtual user PC, Display Wireless Network Ordinary internet connection
2007/06/05NOSSDAV 200711 Application example Paintball war game 1.Avatars, guns and targets are shared 2.Each user sees other real and virtual users 3.Virtual characters like dinosaur can be introduced FAIRVIEW has necessary functions to realize this kind of application. 13 22
2007/06/05NOSSDAV 200712 Functionalities of FAIRVIEW Real user (mobile user) Virtual user (PC user) shared space
2007/06/05NOSSDAV 200713 Functionalities of FAIRVIEW Real user (mobile user) Virtual user (PC user) shared space Sharing Objects Challenge1:sharing objects among real/virtual users Problem: How to make users observe the shared objects? Our approach: prepare 3D geometry data of objects beforehand and draw the object at user terminals. Even when we want to share a new object, real-time modeling method  can be used.
2007/06/05NOSSDAV 200714 Functionalities of FAIRVIEW Real user (mobile user) Virtual user (PC user) Sharing Objects Challenge2: allowing users to observe moving objects Problem: How to capture movement of real objects? Our approach: measure position (x, y, z) and direction (angleH, angleV) continuously using positioning sensors, e.g., GPS, Wii Controller(6-axis sensor), etc… or using web camera and ARtoolkit  shared space
2007/06/05NOSSDAV 200715 Functionalities of FAIRVIEW Real user (mobile user) Virtual user (PC user) Moving virtual objects Challenge3: allowing users to make action to objects (i.e., push) note that users can make action only to virtual objects. Problem: How to reproduce realistic reaction? Our approach: use physics simulation of each virtual object. shared space
2007/06/05NOSSDAV 200716 Our target problems A lot of objects and users can exist at the same time. Positions and directions of objects have to be delivered in real time. Mobile terminals do not have much computation power. All functionalities have to be realized with ordinary devices. Solving these problems is the main contribution of this research.
2007/06/05NOSSDAV 200718 …… How to distribute load for event delivery Central server Direct communication among user We introduce a typical load distribution technique used in MMOG. costly
2007/06/05NOSSDAV 200719 Load distribution on event delivery  Some of the user nodes are used as servers –One server (area node) is assigned to each sub-area Area node collects events, process and send the events back to user nodes Communication load is reduced using a load balancing tree Some powerful user nodes act as servers (area nodes) Load balancing tree
2007/06/05NOSSDAV 200720 Communication architecture for FAIRVIEW real user nodes Wireless AP virtual user nodes there are real user nodes and virtual user nodes. There are real user nodes and virtual user nodes. There is a wireless access point for real user nodes. internet
2007/06/05NOSSDAV 200721 Communication architecture for FAIRVIEW area node real user nodes virtual user nodes Introduce area nodes. Area nodes process events (change of position/direction of object, action to object) of corresponding sub-area. Wireless AP Area node
2007/06/05NOSSDAV 200722 Physics simulation for reaction of v-objects To realistically display virtual objects Reproduce movements of objects by physics simulation Physics simulation takes too much power on mobile terminals. We introduce nodes to manage each object, which we call the object management node.
2007/06/05NOSSDAV 200723 Introducing object management node area node real user nodes om-nodes virtual user nodes AP (for wireless users) Introduce object management nodes (om-nodes are assigned to powerful user nodes)
2007/06/05NOSSDAV 200724 Congestion in communication architecture area node real user nodes om-nodes virtual user nodes AP (for wireless users) As the number of objects increases, traffic amount may exceed network bandwidth capacity.
2007/06/05NOSSDAV 200725 Introducing bandwidth control node area node bwc-nodes real user nodes om-nodes virtual user nodes Introduce bwc- nodes, which reduce traffic amount within the available bandwidth to user nodes (We will explain how to drop packets, later) AP (for wireless users)
2007/06/05NOSSDAV 200726 A = 64 B = 16 C = 4 D = 2 E = 1 F = 0 Differentiation based on object class When the traffic exceeds available bandwidth, if we uniformly reduce quality (framerate) of all objects, satisfaction of this user will be low. Differentiate quality of objects based on object class User specifies importance value for each object. Bwc-node assigns bandwidth for each object according to importance value –we automatically decide importance value of each object according to the distance and direction as shown below –Update frequency of each object is changed according to assigned bandwidth
2007/06/05NOSSDAV 200727 Example for QoS adaptation Importance value of each object is decided by relative position. U O1O1 O3O3 O2O2 A = 64 B = 16 C = 4 D = 2 E = 1 F = 0 O 1 ’s importance is 64 (zone A) O 2 ’s importance is 1 (zone E) O 3 ’s importance is 16 (zone B)
2007/06/05NOSSDAV 200728 Example for QoS adaptation When user’s available bandwidth is 1 Mbps and each of three objects takes 0.5Mbps for position/direction updates, the sum will be 1.5Mbps. area node bwc-nodes om-nodes user nodes U O1O1 O3O3 O2O2 O1O1 O3O3 O2O2 Users importance Imp(O 1 ) = 5 Imp(O 2 ) = 2 Imp(O 3 ) = 3 Bandwidth control node dropping packets according to importance value.
2007/06/05NOSSDAV 200729 Collection and delivery of events area node bwc-nodes real user nodes om-nodes virtual user nodes AP (for wireless users) When a user generates an event, the event is sent to area node
2007/06/05NOSSDAV 200730 Collection and delivery of events area node bwc-nodes real user nodes om-nodes virtual user nodes Events regarding to objects are sent to corresponding om-nodes AP (for wireless users)
2007/06/05NOSSDAV 200731 Collection and delivery of events area node bwc-nodes real user nodes om-nodes virtual user nodes AP (for wireless users) Events are sent to bwc- nodes at regular intervals.
2007/06/05NOSSDAV 200732 Collection and delivery of events area node bwc-nodes real user nodes om-nodes virtual user nodes AP (for wireless users) Bwc-nodes reduce traffic by dropping packets.
2007/06/05NOSSDAV 200733 Collection and delivery of events area node bwc-nodes real user nodes om-nodes virtual user nodes AP (for wireless users) Bwc-nodes reduce traffic by dropping packets.
2007/06/05NOSSDAV 200734 Collection and delivery of events area node bwc-nodes real user nodes om-nodes virtual user nodes AP (for wireless users) Bwc-nodes limit traffic within the amount available for users
2007/06/05NOSSDAV 200736 Traffic and update frequency Purpose of this experiment is to know how the proposed method regulates the traffic required for position/direction updates within the available bandwidth how much satisfaction users obtain when observing moving objects Configuration: Real user :100 (random placement) Virtual user :100 (random placement) Real object :50 ～ 2500 (random placement) Virtual object :50 ～ 2500 (random placement) Importance of object :64 ， 16 ， 4 ， 2 ， 1 ， 0 Real user bandwidth (share) :10 Mbps Virtual user bandwidth :5 Mbps
2007/06/05NOSSDAV 200737 Required traffic When QoS adaptation is used, traffic is kept below the available bandwidth. RU = Real User VU = Virtual User avail -able BW When the number of objects exceed 500, the required traffic amount exceeds the available bandwidth.
2007/06/05NOSSDAV 200738 Achieved quality in frames/sec (virtual user) Virtual user keeps higher FPS in A and B, than uniform. ABCDEFABCDEF Virtual users see important objects on zone A with significantly higher quality even when the number of objects is large.
2007/06/05NOSSDAV 200739 Achieved quality in FPS (real user) Real user keeps higher FPS in zone A than uniform. ABCDEFABCDEF bwc-nodes real user nodes AP The impact of QoS adaptation is smaller than virtual users, since available b/w between real user nodes and AP is shared.
2007/06/05NOSSDAV 200740 Subjective evaluation of QoS adaptation Purpose of this experiment: To check subjective satisfaction of object quality by QoS adaptation Test procedure: Testees see composite movies with resolution and update frequency calculated by our QoS adaptation method The movies show a person gesturing one of the following shapes – 〇，△，▽， □ ，◇, etc. We asked 6 testees to answer several questions. ABCDEFABCDEF A B C
2007/06/05NOSSDAV 200741 Result of questionnaire A B C This table shows that the testees recognized the important object more accurately and quickly with our QoS adaptation method.
2007/06/05NOSSDAV 200742 Conclusion We proposed FAIRVIEW. Enables object sharing for CSCW usage P2P-based event delivery mechanism QoS adaptation mechanism Future work Improving QoS adaptation in wireless LAN Testing QoS adaptation by prototype system Implementing as a middleware Implementing application
2007/06/05NOSSDAV 200743 Thank you. Any questions?
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