Communication through virtual active objects overlaid onto the real world

A SpaceTag is a virtual object that can be accessed only from limited locations and time period. Users of the SpaceTag System can see and create SpaceTags using a portable terminal with a location sensor. We have categorized it as an overlaid virtual system, in which virtual objects are overlaid onto the real world based on time and space coordinates. This architecture is more promising, general purpose, low-cost, and more realistic than other location-aware system architectures like augmented reality that attaches virtual information onto real objects. The SpaceTag System can be offered as a public information service that is a common platform for gaming, advertising, city guide information, etc. We have already implemented a prototype. In this paper, active SpaceTags are additionally proposed. They are enabled to interact autonomously with human and other SpaceTags, realizing new applications of interactive games, virtual creatures (SpacePet), etc. The computation model of active SpaceTag is described here. This paper also gives a discussion by regarding the SpaceTag System as a CVE. It is a considered as special CVE that has a same space/time coordinates as the real world. SpaceTags and SpacePets can be regarded as objects and active objects in the virtual space, but they are projected onto the real world. Users can communicate with each other through these objects. This paper also describes how such communication occurs.