"The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it."
Father of Ubiquitous Computing
Mark Weiser's imaginative statement summarizes the importance of Pervasive or Ubiquitous Computing, which helps the user access to the computational environment, everywhere at all times and by means of any device. This is a rapidly developing area which focuses on integration of Information and Communication Technologies into human environment and is made possible with the growing connectivity & computing devices gradually becoming smaller and powerful. In Ubiquitous Computing entities like clothing, coffee mug, consumer goods, car, human body etc can be embedded with chips/devices executing intelligent software. These devices range from a few millimeters in size like sensors to several meters like displays and are connected via wireless or wired links to one another.
Ubiquitous Computing has many potential application areas like health, home care, environment monitoring, sales automation, Learning etc. Key challenge for Ubiquitous information society would be to arrive at digital convergent environment and infrastructure integrating broadcasting, communications and Internet. Conventional mobility objective of providing computation "all the time and everywhere" is a reactive approach to information access, whereas in Ubiquitous Computing it characterizes a proactive approach to seamlessly add a person's knowledge and decision making ability. Major difficulty in this approach lies in developing middleware and applications that will continually adapt to the environment and keep working as people move or change the devices.
The technology perspective of Ubiquitous Computing involves a variety of software and hardware challenges. The most prevalent issues are Mobility, Scalability, Heterogeneity, Privacy & Trust, Dependability & Security, Spontaneous Interoperation, Transparent user interaction, Integration and Invisibility. Other UbiComp system design challenges include varying hardware platforms, diverse topologies, need for service discovery, middleware, context awareness, and location awareness in a limited processing, communication and memory constraints. The broad vision of UbiComp has thus inspired cohesive research from several fields among which the most prominent are Embedded Computing, Human Computer Interface, Mobile Computing, Sensor Networks and Web Technologies. Researchers across the world have taken up various initiatives to address the various challenges while making Ubiquitous Computing a reality.