Ubiquitous computing, also known as calm computing , ambient intelligence, and pervasive computing, is the integration of our computing environments into the real world. Human-computer interaction in this computing paradigm can occur through various devices, in different locations, and through different mediums.
Ubiquitous computing is the third computing paradigm, following the many-to-one model of mainframe computers and the one-to-one model of personal computing, referring to human-to-computer relationships. This third wave is denoted by many-to-one relationships, referring to many computers to one user. These emerge as part of the environment, as opposed to a stand-alone machine. Some common themes are integration of multiple forms of hardware into everyday tasks and objects, background computing, and ever-present interaction.
There are several systems that support ubiquitous computing in modern society, including the Internet, operating systems, both mobile and otherwise, sensors, user interfaces, networks, microprocessors, and location and positioning software.
The founder of ubiquitous computing is Mark Weiser , who was one of the chief scientists at Xerox PARC in Palo Alto, California. He officially introduced this topic to the world in his 1991 paper, The Computer for the 21st Century. The incarnation of the concept can be traced back to 1988 where it was worked on in Xerox PARC Labs in forms of "tabs", "pads", and "boards".
Within his 1996 paper on Ubiqutious Computing , Weiser relates about how it is the third wave in computing. This was prefaced by the mainframe computers, which were one entity shared by many different people. Following this was the personal computer era, which we are in today, where there is a one-to-one relationship between each person and computer. Ubiquitous computing then, or calm technology, denotes the period where technology will recede into the background, becoming integrated with our environments, and thus will be a relationship of many "computers" to one person.
Other Notable Individuals
Based in Cambridge University, Hopper proposed the concept of teleporting, which is based on the concept of applications following a user as they move through different environments. Some of his current research focuses on computer networks, multimedia systems, Virtual Network Computing, and sentient computing. Hoppers's most cited research is his paper on the Active Badge Location System, which is based on locating people and objects indoors.  Some of his other research focuses on the ethical issues surrounding surveillance and the privacy concerns associated with them. His most recent research examines the use of computers in securing the sustainability of our planet and its resources.
Researched and worked on an "Active Badge System", which combines personal mobility and computing to create an advanced location computing system . His research interests also include mobile and ubiquitous computing, distributed systems, context-aware operation, and electronic identification. Want has over 25 years of experience working in the field of mobile computing. He is currently a Research Scientist at Google. 
Within his initial paper in 1991, Weiser introduces three different forms of devices to be used in ubiquitous systems. These are tabs, pads, and boards.
Tabs are on the scale of centimeters, which can be worn on one's person. The are the smallest components of what Weiser terms as embodied reality. Some of his examples include clip-on computers the size of an ID for scanners and receivers, which are modernly represented as RFID tags.
The second device introduced by Weiser is the pad, which range between a standard 8.5" by 11" sheet of paper. Their main potential, according to Weiser, comes from their being able to be used anywhere, much like scrap paper.
The board, now at a scale of about a yard, serve multiple purposes. Placed in different rooms, casual computer interaction can enhance different rooms in a building. Additionally, these can share information between and within different areas, interconnecting buildings and rooms. One benefit of boards is that they can serve to display personalized, public information.
Some notable modern examples of ubiquitous computing can be seen in the form of sensors such as Radio-frequecy Identification (RFID) Tags . These perform different actions upon being scanned, and can hold data in the form of links and pre-programmed activities.
Internet of Things
The evolution of ubiquitous computing has lead to the latest coined term, Internet of Things (IOT). The main difference is that ubiquitous computing is a scholarly term which describes computing as anywhere and everywhere. IOT is utilized in dialogue including the objects involved, like an oven or a consumer's alarm system. IOT is far more familiar in the public eye with popular devices like the Amazon Alexa already permeating over 20 million consumer households. 
The most prevalent ethical issues currently plaguing ubiquitous computing revolve around privacy. With the advent of computing being integrated into different environments, new contexts arise that there are no previous notions for. Particularly, a research paper published in 2009 by Linda Little and Pam Briggs analyzes how the currently established privacy principles can grow and adapt in the face of new environments and considerations.
More specifically, Little and Briggs examine if users will have enough confidence in the procedures developed to administer and manage different privacy preferences. Motahari, et al., (2007) present the argument that more holistic approach is needed to address current privacy threats in ubiquitous computing. Further, privacy threats are more likely to depend on different situations, for which systems must be developed in privacy management that are context-rich. This presents the user with more detailed information upon which to base privacy considerations, thereby allowing tailored privacy management in environments within ubiquitous computing.
More specifically, long-term policy making is an issue in ubiquitous computing that has significant ethical implications. With new forms of interaction and a merging of environments comes the need for strong ethical bases that can be implemented and reinforced through policy making that is developed through the joint efforts of ubiquitous system developers and the makers of the policies themselves.
In this way, policy making will be created to regulate both the use and creation of such systems, which can have embedded values in their designs, as defined by Phillip Brey in his article on values in technology and disclosive computer ethics. 
In order to determine the proper ethical considerations in ethical computing, the notion of how content can be represented becomes an issue. When analyzed from a purely digital or purely physical environment, a clear distinction can be formed.
The issue with ubiquitous computing is that the digital and physical worlds merge and coexist as one. In this ambient, the communication of information through environments that are pervasive and ubiquitous is defined as content. Artur Lugmayr explored the components of such an environment, separating them into ambient media form, ambient media content, and ambient media technology. The principles of ambient media are defined by him as manifestation, intelligence, morphing, and experience .
- The Coming Age of Calm Technology
- Mark Weiser
- The Computer for the 21st Century
- Ubiquitous Computing
- Active Badge Location System
- The Active Badge Location System
- Roy Want
- Efficient Object Identification with Passive RFID Tags
- Bezos says 20 million amazon alexa devices sold
- Values in Technology and Disclosive Computer Ethics
- Semantic ambient media—an introduction