The design of Ambient Intelligent Systems (AISs) is discussed in the
context of assistive technologies. The main issues include ubiquitous communications,
context awareness, natural interactions and heterogeneity, which are
analyzed using some examples. A layered architecture is proposed for heterogeneous
sub-systems integration with three levels of interactions that may be
used as a framework to design assistive AISs.Ministerio de Ciencia y Tecnología TIC2001-1868-C0
