QoS Management for Live Videos in Networked Virtual Spaces

VRML (Virtual Reality Modeling Language) is getting popular on Internet. VRML version 2.0 provides the functions of changing the scenes. Advanced applications of VRML version 2.0 are multi-user spaces. We can be aware of each other in the multi-user spaces. Real time data make 3D CG (Computer Graphics) spaces much richer worlds. However, current style multi-user spaces use only the current location and direction of a user's viewpoint because the network band width of the current Internet is not so broad. We are experimenting incorporating live videos into 3D CG spaces using high speed computer networks and computer graphics workstations. The capability of current computer technology is not enough to deal with live videos in 3D CG spaces. We must find good ways of using this limited current computer technology effectively. The quality of service (QoS) for treating live video in 3D CG spaces is decided by some parameters of live videos such as resolution, frame rate and delay. The QoS of live videos in virtual spaces should be managed using the rules of LoD (Level of Detail) that is the function of the distance from a user's viewpoint to a component object. For example, if an object is near to a user, the object with the highest quality detail should be put in the scene. If the object is far from the user, the object should not be put in the scene or the object with rough representation should be put in the scene.