Videotelephony

 ( Assistive Technology ) 

Videotelephony (also known as videoconferencing or video calling) is the use of audio signal and video for simultaneous two-way communication. Today, videotelephony is widespread. There are many terms to refer to videotelephony. Videophones are standalone devices for video calling (compare Telephone). In the present day, devices like smartphones and computers are capable of video calling, reducing the demand for separate videophones. Videoconferencing implies group communication.Mulbach et al, 1995. pg. 291. Videoconferencing is used in telepresence, whose goal is to create the illusion that remote participants are in the same room.

The concept of videotelephony was conceived in the late 19th century, and versions were available to the public starting in the 1930s. Early demonstrations were installed at booths in post offices and shown at various world expositions. In 1970, AT&T launched the first commercial personal videotelephone system. In addition to videophones, there existed image phones which exchanged still images between units every few seconds over conventional telephone lines. The development of advanced codec, more powerful , and high-bandwidth Internet service in the late 1990s allowed digital videophones to provide high-quality low-cost color service between users almost any place in the world.

Applications of videotelephony include sign language transmission for deaf and speech-impaired people, distance education, telehealth, and overcoming disability. News media organizations have used videotelephony for broadcasting.

The development of videotelephony as a subscription service started in the latter half of the 1920s in the United Kingdom and the United States, spurred notably by John Logie Baird and Bell Labs. This occurred in part, at least with AT&T, to serve as an adjunct supplementing the use of the telephone. A number of organizations believed that videotelephony would be superior to plain voice communications. Attempts at using normal telephony networks to transmit slow-scan video, such as the first systems developed by AT&T Corporation, first researched in the 1950s, failed mostly due to the poor picture quality and the lack of efficient video compression techniques.

During the first crewed , 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 news media were to become regular users of mobile links to using specially equipped trucks, and much later via special satellite videophones in a briefcase. This technique was very expensive, though, and was not adopted for applications such as telemedicine, distance education, and business meetings.

Decades of research and development culminated in the 1970 commercial launch of AT&T's Picturephone service, available in select cities. However, the system was a commercial failure, chiefly due to consumer apathy, high subscription costs, and lack of network effect—with only a few hundred Picturephones in the world, users had extremely few contacts they could actually call, and interoperability with other videophone systems would not exist for decades.

In 1984, Concept Communication in the United States created a circuit board for standard personal computers that doubled the video frame rate of typical digital videotelephone systems from 15 to 30 frames per second, and reduced the cost from $100,000 to $12,000. The company also secured a patent for a codec for full-motion videoconferencing, first demonstrated at AT&T Bell Labs in 1986.

Very expensive videoconferencing systems continued to rapidly evolve throughout the 1980s and 1990s. Proprietary equipment, software, and network requirements gave way to standards-based technologies that were available for anyone to purchase at a reasonable cost.

While videoconferencing technology was initially used primarily within internal corporate communication networks, one of the first community service uses of the technology started in 1992 through a unique partnership with PictureTel and IBM, which at the time were promoting a jointly developed desktop based videoconferencing product known as the PCS/1. Over the next 15 years, Project DIANE (Diversified Information and Assistance Network) grew to use a variety of videoconferencing platforms to create a multi-state cooperative public service and distance education network consisting of several hundred schools, libraries, science museums, zoos and parks, and many other community-oriented organizations.

In 1992 CU-SeeMe was developed at Cornell by Tim Dorcey et al. In 1995 the first public videoconference between North America and Africa took place, linking a technofair in San Francisco with a techno-rave and cyberdeli in Cape Town. At the 1998 Winter Olympics opening ceremony in Nagano, Japan, Seiji Ozawa conducted the Ode to Joy from Beethoven's Ninth Symphony simultaneously across five continents in near-real-time.

Kyocera conducted a two-year development campaign from 1997 to 1999 that resulted in the release of the VP-210 Visual Phone, the first mobile colour videophone that also doubled as a camera phone for still photos. Kyocera visual phone VP-210, Japan, 1999, Science & Society Picture Library, retrieved August 9, 2013. First mobile videophone introduced, CNN.com website, May 18, 1999. The camera phone was the same size as similar contemporary , but sported a large camera lens and a 5 cm (2 inch) colour TFT display capable of displaying 65,000 colors, and was able to process two video frames per second.Yegulalp, Serdar. Camera phones: A look back and forward , Computerworld, May 11, 2012.

Videotelephony was popularized in the 2000s via free Internet services such as Skype and iChat, web plugins supporting H.26x video standards, and online telecommunication programs that promoted low cost, albeit lower quality, videoconferencing to virtually every location with an Internet connection.

Videotelephony became even more widespread through the deployment of video-enabled such as 2010s iPhone 4, plus videoconferencing and webcam which use Internet telephony. In the upper echelons of government, business, and commerce, telepresence, an advanced form of videoconferencing, has helped reduce the need to travel.

Technological developments by videoconferencing developers in the 2010s have extended the capabilities of videoconferencing systems beyond the boardroom for use with Mobile device that combine the use of video, audio and on-screen drawing capabilities broadcasting in real time over secure networks, independent of location. Mobile collaboration systems now allow people in previously unreachable locations, such as workers on an offshore oil rig, the ability to view and discuss issues with colleagues thousands of miles away. Traditional videoconferencing system manufacturers have begun providing mobile applications as well, such as those that allow for live and still image streaming. VCLink for Mobile Devices—AVer Video Conferencing

The highest ever video call (other than those from aircraft and spacecraft) took place on May 19, 2013, when British adventurer Daniel Hughes used a smartphone with a BGAN satellite modem to make a videocall to the BBC from the summit of Mount Everest, at above sea level.Callaham, John. Man makes the highest Skype video call ever on top of Mount Everest , Neowin.net website, June 25, 2013; which in turn cites:

• Larson, Stephanie. First Skype Call Atop Mt. Everest Raises Thousands for Charity , Skype, June 24, 2013.

The COVID-19 pandemic resulted in a significant increase in the use of videoconferencing. Berstein Research found that Zoom added more subscribers during the first two months of 2020 alone than in the entire year 2019. GoToMeeting had a 20 percent increase in usage, according to LogMeIn. UK based StarLeaf reported a 600 percent increase in national call volumes. Videoconferencing became so widespread during the pandemic that the term Zoom fatigue came to prominence, referring to the taxing nature of spending long periods of time on videocalls. This fatigue refers to the psychological and physiological effects participants involved in videoconferencing. One experimental study from 2021 revealed a link between camera use in videoconferencing and a prediction of fatigue occurrence an individual. Furthermore, a 2022 article in the journal "Computers in Human Behaviour" highlighted a study linking negative attitudes with the use of "self-view" when videoconferencing.

On 21 September 2021, Facebook launched two new versions of its Portal video-calling devices, the Portal Go and Portal Plus. The new video calling devices include the first portable variety of the hardware and number of updates.

Videophones were the earliest form of videotelephony, dating back to initial tests in 1927 by AT&T. During the late 1930s, the post offices of several European governments established public videophone services for person-to-person communications using dual cable circuit telephone transmission technology. In the present day, standalone videophones and UMTS video-enabled are usually used on a person-to-person basis.

Videoconferencing saw its earliest use with AT&T's Picturephone service in the early 1970s. Transmissions were analog over short distances, but converted to digital forms for longer calls, again using telephone transmission technology. Popular corporate video-conferencing systems in the present day have migrated almost exclusively to digital ISDN and IP transmission modes due to the need to convey the very large amounts of data generated by their cameras and microphones. These systems are often intended for use in conference mode, that is by many people in several different locations, all of whom can be viewed by every participant at each location.

Telepresence systems are a newer, more advanced subset of videoconferencing systems, meant to allow higher degrees of video and audio fidelity. Such high-end systems are typically deployed in corporate settings.

Mobile collaboration systems are another recent development, combining the use of video, audio, and on-screen drawing capabilities using newest generation Mobile device broadcasting over secure networks, enabling multi-party conferencing in real time, independent of location. Proximity chat is another alternative mode, focused on the flexibility of small group conversations.

A more recent technology encompassing these functions is TV cams. TV cams enable people to make video calls using video calling services, like Skype on their TV, without using a PC connection. TV cams are specially designed video cameras that feed images in real time to another TV camera or other compatible computing devices like smartphones, tablets and computers.

are popular, relatively low-cost devices that can provide live video and audio streams via personal computers, and can be used with many software clients for both video calls and videoconferencing.Solomon Negash, Michael E. Whitman. Editors: Solomon Negash, Michael E. Whitman, Amy B. Woszczynski, Ken Hoganson, Herbert Mattord. Handbook of Distance Learning for Real-Time and Asynchronous Information Technology Education , Idea Group Inc (IGI), 2008, p. 17, , . Note costing: "...students had the option to install a webcam on their end (a basic webcam costs about $40.00) to view the class in session."

Each of the systems has its own advantages and disadvantages, including video, capital cost, degrees of sophistication, transmission capacity requirements, and Indirect costs.

• Webcam videophone and videoconferencing systems, either stand-alone or built-in, that serve as complements to personal computers, connected to other participants by computer network and VoIP networks—lowest direct cost, assuming the users already possess computers at their respective locations. Quality of service can range from low to very high, including high definition video available on the latest model webcams. A related and similar device is a TV camera which is usually small, sits on top of a TV, and can connect to it via its HDMI port, similar to how a webcam attaches to a computer via a USB port.
• —low to midrange cost. The earliest standalone models operated over either plain old telephone service (POTS) lines on the PSTN telephone networks or more expensive ISDN lines, while newer models have largely migrated to Internet Protocol line service for higher image resolutions and sound quality. Quality of service for standalone videophones can vary from low to high;
• Huddle room or all-in-one systems —low to midrange cost, newer endpoint category based on standard videoconferencing systems, but defined by the camera, microphone(s), speakers, and codec contained in a single piece of hardware. Typically used in small to medium spaces where beamforming located in the system are sufficient, in lieu of table or ceiling microphones in closer proximity to the in-room participants. Quality of service is comparable to standard videoconferencing systems, varying from moderate to high. Some manufacturers' huddle room systems do not include the codec within the soundbar-shaped unit, rather only camera, microphone, and speakers. These systems are usually still classified as huddle room systems, but, like webcams, rely on a USB connection to an external device, usually a PC, to process the video codec responsibilities. Despite its name, video conferencing systems for Huddle Rooms prevent participants from huddling close together to be seen in the camera. All-in-one systems for these types of rooms range from wide angles such as 110° Horizontal field of view (FOV) to as much as 360° FOV that allow a full view of the room.
• Videoconferencing systems—midrange cost, usually using multipoint control units or other bridging services to allow multiple parties on videoconference calls. Quality of service can vary from moderate to high.
• Telepresence—highest capabilities and highest cost. Full high-end systems can involve specially built teleconference rooms to allow expansive views with very high levels of audio and video fidelity, to permit an 'immersive' videoconference. When the proper type and capacity transmission lines are provided between facilities, the quality of service reaches state-of-the-art levels.

• A live conversation is needed
• Non-verbal (visual) information is an important component of the conversation
• The parties of the conversation cannot physically come to the same location
• The expense or time of travel is a consideration

Bill Gates said in 2001 that he used videoconferencing "three or four times a year", because digital scheduling was difficult and "if the overhead is super high, then you might as well just have a face-to-face meeting". Some observers argue that three outstanding issues have prevented videoconferencing from becoming a widely adopted form of communication, despite the ubiquity of videoconferencing-capable systems.Van Meggelen, Jim. The Problem With Video Conferencing , 2005.

• Eye contact: Eye contact plays a large role in conversational turn-taking, perceived attention and intent, and other aspects of group communication.Vertegaal, "Explaining Effects of Eye Gaze on Mediated Group Conversations: Amount or Synchronization?" ACM Conference on Computer Supported Cooperative Work, 2002. While traditional telephone conversations give no eye contact cues, many videoconferencing systems are arguably worse in that they provide an incorrect impression that the remote interlocutor is avoiding eye contact. Some telepresence systems have cameras located in the screens that reduce the amount of parallax observed by the users. This issue is also being addressed through research that generates a synthetic image with eye contact using stereo reconstruction.Computer vision approaches to achieving eye contact appeared in the 1990s, such as Teleconferencing Eye Contact Using a Virtual Camera, ACM CHI 1993. More recently gaze correction systems using only a single camera have been shown, such as. Microsoft's GazeMaster system.
  Telcordia Technologies, formerly Bell Communications Research, owns a patent for eye-to-eye videoconferencing using rear projection screens with the video camera behind it, evolved from a 1960s U.S. military system that provided videoconferencing services between the White House and various other government and military facilities. This technique eliminates the need for special cameras or image processing. Google Patent
• Appearance consciousness: A second psychological problem with videoconferencing is being on camera, with the video stream possibly even being recorded. The burden of presenting an acceptable on-screen appearance is not present in audio-only communication. Early studies by Alphonse Chapanis found that the addition of video actually impaired communication, possibly because of the consciousness of being on camera.
• Signal latency: The information transport of digital signals in many steps need time. In a telecommunicated conversation, an increased latency (time lag) larger than about 150–300 ms becomes noticeable and is soon observed as unnatural and distracting. Therefore, next to a stable large bandwidth, a small total round-trip time is another major technical requirement for the communication channel for interactive videoconferencing.Percy, Alan. Understanding Latency
• Bandwidth and quality of service: In some countries, it is difficult or expensive to get a high-quality connection that is fast enough for good-quality videoconferencing. Technologies such as ADSL are usually provided as two separate lines (for uplink/downlink) because each has limited upload speeds and cannot upload and download simultaneously at full speed. As Internet speeds increase, higher quality and high-definition videoconferencing will become more readily available.
• Complexity of systems: Most users are not technically experienced and want a simple interface. In hardware systems, an unplugged cord or an unresponsive remote control is seen as a failure, contributing to a perceived unreliability. Successful systems are backed by support teams who can provide fast assistance when required.
• Perceived lack of interoperability: Not all systems can readily interconnect; for example, ISDN and IP systems require a gateway. Popular software solutions cannot easily connect to hardware systems. Some systems use different standards, features, and qualities which can require additional configuration when connecting to dissimilar systems. Free software systems circumvent this limitation by making it relatively easy for a single user to communicate over multiple incompatible platforms.
• Expense of commercial systems: Well-designed telepresence systems require specially designed rooms which can cost hundreds of thousands of dollars to fit out their rooms with codecs, integration equipment (such as Multipoint Control Units), high fidelity sound systems, and furniture. Monthly charges may also be required for bridging services and high-capacity broadband service.

These are some of the reasons many organizations only use the systems internally, where there is less risk of loss of customers. An alternative for those lacking dedicated facilities is the rental of videoconferencing-equipped meeting rooms in cities around the world. Clients can book rooms and turn up for the meeting, with all technical aspects being prearranged and support being readily available if needed. The issue of eye contact may be solved with advancing technology, including smartphones which have the screen and camera in essentially the same place. In developed countries, the near-ubiquity of , , and computers with built-in audio and webcams removes the need for expensive dedicated hardware.

The other components required for a videoconferencing system include:

• Video input: (PTZ / 360° / Fisheye lens) video camera, or webcam
• Video output: computer monitor, television, or Video projector
• Audio input: , CD/DVD player, cassette player, or any other source of PreAmp audio outlet.
• Audio output: usually associated with the display device or telephone
• Data transfer: analog or digital telephone network, LAN, or Internet
• Computer: a data processing unit that ties together the other components, does the compressing and decompressing, and initiates and maintains the data linkage via the network.

There are basically three kinds of videoconferencing and videophone systems:

1. Dedicated systems have all required components packaged into a single piece of equipment, usually a console with a high quality video camera. These cameras can be controlled at a distance to pan left and right, tilt up and down, and zoom. They became known as PTZ cameras. The console contains all electrical interfaces, the control computer, and the software or hardware-based codec. Omnidirectional microphones are connected to the console, as well as a TV monitor with loudspeakers and/or a video projector. There are several types of dedicated videoconferencing devices:
1. Large group videoconferencing are built-in, large, expensive devices used for large rooms such as conference rooms and auditoriums.
2. Small group videoconferencing are either non-portable or portable, smaller, less expensive devices used for small meeting rooms.
3. Individual videoconferencing are usually portable devices, meant for single users, and have fixed cameras, microphones, and loudspeakers integrated into the console.
2. Desktop systems are add-ons (hardware boards or software codec) to normal PCs and laptops, transforming them into videoconferencing devices. A range of different cameras and microphones can be used with the codec, which contains the necessary codec and transmission interfaces.
3. WebRTC platforms use a web browser instead of dedicated native application software. Solutions such as Adobe Connect and Cisco WebEx can be accessed using a URL sent by the meeting organizer, and various degrees of security can be attached to the virtual room. Often the user must download and install a browser extension to enable access to the local camera and microphone and establish a connection to the meeting. But WebRTC does not require any special software, instead a WebRTC-compliant web browser itself provides the facilities for 1-to-1 and 1-to-many videoconferencing calls. Several enhancements to WebRTC are provided by independent vendors.

Johnston, Alan B. (2025). 9781580531689, Artech House. ISBN 9781580531689