Book excerpt: Pervasive systems, due to inexpensive wireless technology can now be implemented easily and local and network advanced applications can be joined anytime simply by using a mobile terminal (cell phone, PDA, smartphone etc.) Pervasive systems free people from conventional interaction with desktop and laptop computers thereby allowing a new human-environment interaction to take place on the basis of wireless multimedia communication.Addressing the theoretical fundamentals of pervasive systems as they are studied and developed in the major research laboratories, Pervasive Systems and Ubiquitous Computing is aimed at MSc and PhD engineering students