Finally, in the 1990s, Internet Protocol-based videoconferencing became possible, and more efficient video compression technologies were developed, permitting desktop, or personal computer (PC)-based videoconferencing.In 1992 CU-See Me was developed at Cornell by Tim Dorcey et al.The news media were to become regular users of mobile links to satellites using specially equipped trucks, and much later via special satellite videophones in a briefcase.
Videoconferencing implies the use of this technology for a group or organizational meeting rather than for individuals, in a videoconference.
Telepresence may refer either to a high-quality videotelephony system (where the goal is to create the illusion that remote participants are in the same room) or to meetup technology, which goes beyond video into robotics (such as moving around the room or physically manipulating objects).
Videotelephony developed in parallel with conventional voice telephone systems from the mid-to-late 20th century.
Very expensive videoconferencing systems rapidly evolved throughout the 1980s and 1990s from proprietary equipment, software and network requirements to standards-based technologies that were available for anyone to purchase at a reasonable cost.
The first dedicated systems started to appear as ISDN networks were expanding throughout the world.
One of the first commercial videoconferencing systems sold to companies came from Picture Tel Corp., which had an Initial Public Offering in November, 1984.
During the first manned space flights, NASA used two radio-frequency (UHF or VHF) video links, one in each direction.
TV channels routinely use this type of videotelephony when reporting from distant locations.
The development of advanced video codecs, more powerful CPUs, and high-bandwidth Internet telecommunication services in the late 1990s allowed videophones to provide high quality low-cost colour service between users almost anyplace in the world that the Internet is available.
Although not as widely used in everyday communications as audio-only and text communication, useful applications include sign language transmission for deaf and speech-impaired people, distance education, telemedicine, and overcoming mobility issues.
Such an antecedent usually consisted of two closed-circuit television systems connected via coax cable or radio.