Linking between Personal Smart Spaces

One approach to the development of pervasive systems is based on the notion of Personal Smart Spaces (PSSs). A PSS is implemented as an ad hoc network and may be either fixed or mobile. When one PSS encounters another, communication is established between them. This may be used to alert one user to the presence of another, or a fixed smart space to the presence of a mobile user. There is considerable potential for applications using this type of functionality and it could become an important component of pervasive systems in the future. However, one problem with this is that it is difficult to detect when one PSS is close enough to another to be relevant. The Persist project has built a pervasive system based on PSSs and investigated the problems of their interaction in order to demonstrate this functionality. This paper discusses the problem of proximity and attempts to address it.