Videotelephony

Advances in video compression allowed digital video streams to be transmitted over the Internet, which was previously difficult due to the impractically high bandwidth requirements of uncompressed video. To achieve Video Graphics Array (VGA) quality video without compression, it would require a bandwidth of over 92 Mbps.[5] A common compression technique used to significantly reduce bandwidth requirements in videotelephony and videoconferencing is the discrete cosine transform (DCT),[5][6] developed by Nasir Ahmed, T. Natarajan and K. R. Rao in 1973.[7] The DCT algorithm was the basis for the first practical video coding standard that was useful for online videoconferencing, H.261, standardised by the ITU-T in 1988, and subsequent H.26x video coding standards.[6]

In the 1980s, digital telephony transmission networks became possible, such as with ISDN networks, assuring a minimum bit rate (usually 128 kilobits/s) for compressed video and audio transmission. During this time, there was also research into other forms of digital video and audio communication. Many of these technologies, such as the Media space, are not as widely used today as videoconferencing but were still an important area of research.[8][9] 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 PictureTel Corp., which had an initial public offering in November, 1984.

In 1984, Concept Communication in the United States replaced the 100-pound (45 kg), US$100,000 computers necessary for teleconferencing, with a $12,000 circuit board that doubled the video frame rate from 15 to 30 frames per second, and which reduced the equipment to the size of a circuit board fitting into standard personal computers.[10] The company also secured a patent for a codec for full-motion videoconferencing, first demonstrated at AT&T Bell Labs in 1986.[10][11]

Global Schoolhouse students communicating via CU-SeeMe, shown here with a video frame rate between 0.9 and 3 frames per second (1993)

Videoconferencing systems throughout the 1990s rapidly evolved from very expensive proprietary equipment, software, and network requirements to a standards-based technology readily available to the general public at a reasonable cost.

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-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.

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.

The Kyocera VP-210 Visual Phone was the first commercial mobile videophone (1999).

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.[12][13] The camera phone was the same size as similar contemporary mobile phones, 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.[13][14]

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.

With the rapid improvements and popularity of the Internet, videotelephony has become widespread through the deployment of video-enabled mobile phones such as 2010s iPhone 4, plus videoconferencing and computer webcams which use Internet telephony. In the upper echelons of government, business, and commerce, telepresence technology, an advanced form of videoconferencing, has helped reduce the need to travel.

In May 2005, the first high definition videoconferencing systems, produced by LifeSize Communications, were displayed at the Interop trade show in Las Vegas, Nevada, able to provide video at 30 frames per second with a 1280 by 720 display resolution.[15][16] Polycom introduced its first high definition videoconferencing system to the market in 2006. As of the 2010s, high-definition resolution for videoconferencing became a popular feature, with most major suppliers in the videoconferencing market offering it.

Technological developments by videoconferencing developers in the 2010s have extended the capabilities of videoconferencing systems beyond the boardroom for use with hand-held mobile devices 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.[17]

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 8,848 metres (29,029 ft) above sea level.[18]

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.[19] UK based StarLeaf reported a 600 percent increase in national call volumes.[20] 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.[21]

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.[22]

From the least to the most expensive systems:

• Web camera videophone and videoconferencing systems, either stand-alone or built-in, that serve as complements to personal computers, connected to other participants by computer 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.
• Videophones—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 microphone arrays 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 systems—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.

Dual display: A mid-2000's Polycom VSX 7000 system and camera used for videoconferencing, with two displays for simultaneous broadcast from separate locations

A videoconference meeting facilitated by Google Hangouts

The core technology used in a videotelephony system is digital compression of audio and video streams in real time. The hardware or software that performs compression is called a codec (coder/decoder). Compression rates of up to 1:500 can be achieved. The resulting digital stream of 1s and 0s is subdivided into labeled packets, which are then transmitted through a digital network of some kind (usually ISDN or IP).

The other components required for a videoconferencing system include:

• Video input: (PTZ / 360° / Fisheye) video camera, or webcam
• Video output: computer monitor, television, or projector
• Audio input: microphones, CD/DVD player, cassette player, or any other source of PreAmp audio outlet.
• Audio output: usually loudspeakers 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 remote controlled 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. Most of the desktops systems work with the H.323 standard.
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 internet browser itself provides the facilities for 1-to-1 and 1-to-many videoconferencing calls. Several enhancements to WebRTC are provided by independent vendors.

Videoconferencing systems use several methods to determine which video feed or feeds to display.[32]^: 11–16

Continuous Presence simply displays all participants at the same time, usually with the exception that the viewer either does not see their own feed, or sees their own feed in miniature.

Voice-Activated Switch selectively chooses a feed to display at each endpoint, with the goal of showing the person who is currently speaking. This is done by choosing the feed (other than the viewer) which has the loudest audio input (perhaps with some filtering to avoid switching for very short-lived volume spikes). Often, if no remote parties are currently speaking, the feed with the last speaker remains on the screen.

Acoustic echo cancellation (AEC) is a processing algorithm that uses the knowledge of audio output to monitor audio input and filter from it noises that echo back after some time delay. If unattended, these echoes can be re-amplified several times, leading to problems including:

• The remote party hearing their own voice coming back at them (usually significantly delayed)
• Strong reverberation, which makes the voice channel useless
• Howling created by feedback

Echo cancellation is a processor-intensive task that usually works over a narrow range of sound delays.

Deutsche Telekom T-View 100 ISDN-type videophone meant for home offices and small businesses, with a lens cover which can be rotated upward for privacy

Videophones have historically employed a variety of transmission and reception bandwidths, which can be understood as data transmission speeds. The lower the transmission/reception bandwidth, the lower the data transfer rate, resulting in a progressively limited and poorer image quality (i.e. lower resolution and/or frame rate). Data transfer rates and live video image quality are related but are also subject to other factors such as data compression techniques. Some early videophones employed very low data transmission rates with a resulting poor video quality.

Broadband bandwidth is often called high-speed, because it usually has a high rate of data transmission. In general, any connection of 256 kbit/s (0.256 Mbit/s) or greater is more concisely considered broadband Internet. The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) recommendation I.113 has defined broadband as a transmission capacity at 1.5 to 2 Mbit/s. The Federal Communications Commission (United States) definition of broadband is 25 Mbit/s.[33]

Currently, adequate video for some purposes becomes possible at data rates lower than the ITU-T broadband definition, with rates of 768 kbit/s and 384 kbit/s used for some videoconferencing applications, and rates as low as 100 kbit/s used for videophones using H.264/MPEG-4 AVC compression protocols. The newer MPEG-4 video and audio compression format can deliver high-quality video at 2 Mbit/s, which is at the low end of cable modem and ADSL broadband performance.

The Tandberg E20 is an example of a SIP-only device. Such devices need to route calls through a Video Communication Server to be able to reach H.323 systems, a process known as "interworking" (2009).

The International Telecommunication Union (ITU) has three umbrellas of standards for videoconferencing:

• ITU H.320 is known as the standard for public switched telephone networks (PSTN) or videoconferencing over integrated services digital networks. While still prevalent in Europe, ISDN was never widely adopted in the United States and Canada.
• ITU H.264 Scalable Video Coding (SVC) is a compression standard that enables videoconferencing systems to achieve highly error resilient Internet Protocol (IP) video transmissions over the public Internet without quality-of-service enhanced lines.[34] This standard has enabled wide scale deployment of high definition desktop videoconferencing and made possible new architectures,[35] which reduces latency between the transmitting sources and receivers, resulting in more fluid communication without pauses. In addition, an attractive factor for IP videoconferencing is that it is easier to set up for use along with web conferencing and data collaboration. These combined technologies enable users to have a richer multimedia environment for live meetings, collaboration and presentations.
• ITU-T V.80: videoconferencing is generally compatibilized with H.324 standard point-to-point videotelephony over regular (POTS) phone lines.

The Unified Communications Interoperability Forum (UCIF), a non-profit alliance between communications vendors, launched in May 2010. The organization's vision is to maximize the interoperability of UC based on existing standards. Founding members of UCIF include HP, Microsoft, Polycom, Logitech/LifeSize Communications, and Juniper Networks.[36][37]

Videoconferencing in the late 20th century was limited to the H.323 protocol (notably Cisco's SCCP implementation was an exception), but newer videophones often use SIP, which is often easier to set up in home networking environments.[38] It is a text-based protocol, incorporating many elements of the Hypertext Transfer Protocol (HTTP) and the Simple Mail Transfer Protocol (SMTP).[39] H.323 is still used, but more commonly for business videoconferencing, while SIP is more commonly used in personal consumer videophones. A number of call-setup methods based on instant messaging protocols such as Skype also now provide video.

Another protocol used by videophones is H.324, which mixes call setup and video compression. Videophones that work on regular phone lines typically use H.324, but the bandwidth is limited by the modem to around 33 kbit/s, limiting the video quality and frame rate. A slightly modified version of H.324 called 3G-324M defined by 3GPP is also used by some cellphones that allow video calls, typically for use only in UMTS networks.[40][41]

There is also H.320 standard, which specified technical requirements for narrow-band visual telephone systems and terminal equipment, typically for videoconferencing and videophone services. It applied mostly to dedicated circuit-based switched network (point-to-point) connections of moderate or high bandwidth, such as through the medium-bandwidth ISDN digital phone protocol or a fractionated high bandwidth T1 lines. Modern products based on H.320 standard usually support also H.323 standard.[42]

The IAX2 protocol also supports videophone calls natively, using the protocol's own capabilities to transport alternate media streams. A few hobbyists obtained the Nortel 1535 Color SIP Videophone cheaply in 2010 as surplus after Nortel's bankruptcy and deployed the sets on the Asterisk (PBX) platform. While additional software is required to patch together multiple video feeds for conference calls or convert between dissimilar video standards, SIP calls between two identical handsets within the same PBX were relatively straightforward.[43]

The components within a videoconferencing system can be divided up into several different layers: User Interface, Conference Control, Control or Signaling Plane, and Media Plane.

Videoconferencing User Interfaces (VUI) can be either graphical or voice-responsive. Many in the industry have encountered both types of interface, and normally a graphical interface is encountered on a computer. User interfaces for conferencing have a number of different uses; they can be used for scheduling, setup, and making a video call. Through the user interface, the administrator is able to control the other three layers of the system.

Conference Control performs resource allocation, management, and routing. This layer along with the User Interface creates meetings (scheduled or unscheduled) or adds and removes participants from a conference.

Control (Signaling) Plane contains the stacks that signal different endpoints to create a call and/or a conference. Signals can be, but are not limited to, H.323 and Session Initiation Protocol (SIP) Protocols. These signals control incoming and outgoing connections as well as session parameters.

The Media Plane controls the audio and video mixing and streaming. This layer manages Real-Time Transport Protocols, User Datagram Packets (UDP) and Real-Time Transport Control Protocol (RTCP). The RTP and UDP normally carry information such the payload type which is the type of codec, frame rate, video size, and many others. RTCP on the other hand acts as a quality control Protocol for detecting errors during streaming.[32]

Simultaneous videoconferencing among three or more remote points is possible in a hardware-based system by means of a Multipoint Control Unit (MCU). This is a bridge that interconnects calls from several sources (in a similar way to the audio conference call). All parties call the MCU, or the MCU can also call the parties which are going to participate, in sequence. There are MCU bridges for IP and ISDN-based videoconferencing. There are MCUs which are pure software and others that are a combination of hardware and software. An MCU is characterized according to the number of simultaneous calls it can handle, its ability to conduct transposing of data rates and protocols, and features such as Continuous Presence, in which multiple parties can be seen on-screen at once. MCUs can be stand-alone hardware devices, or they can be embedded into dedicated videoconferencing units.

The MCU consists of two logical components:

1. A single multipoint controller (MC), and
2. Multipoint Processors (MP), sometimes referred to as the mixer.

The MC controls the conferencing while it is active on the signaling plane, which is simply where the system manages conferencing creation, endpoint signaling and in-conferencing controls. This component negotiates parameters with every endpoint in the network and controls conferencing resources. While the MC controls resources and signaling negotiations, the MP operates on the media plane and receives media from each endpoint. The MP generates output streams from each endpoint and redirects the information to other endpoints in the conference.

Some systems are capable of multipoint conferencing with no MCU, stand-alone, embedded or otherwise. These use a standards-based H.323 technique known as decentralized multipoint, where each station in a multipoint call exchanges video and audio directly with the other stations with no central manager or other bottleneck. The advantages of this technique are that the video and audio will generally be of higher quality because they do not have to be relayed through a central point. Also, users can make ad hoc multipoint calls without any concern for the availability or control of an MCU. This added convenience and quality comes at the expense of some increased network bandwidth, because every station must transmit to every other station directly.[32]

Cloud-based videoconferencing can be used without the hardware generally required by other videoconferencing systems, and can be designed for use by SMEs,[44] or larger international or multinational corporations like Facebook.[45][46] Cloud-based systems can handle either 2D or 3D video broadcasting.[47] Cloud-based systems can also implement mobile calls, VOIP, and other forms of video calling. They can also come with a video recording function to archive past meetings.[48]

In the United States, videoconferencing has allowed testimony to be used for an individual who is unable or prefers not to attend the physical legal settings or would be subjected to severe psychological stress in doing so, however, there is a controversy on the use of testimony by foreign or unavailable witnesses via video transmission, regarding the violation of the Confrontation Clause of the Sixth Amendment of the U.S. Constitution.[53]

In a military investigation in North Carolina, Afghan witnesses have testified via videoconferencing.

In Hall County, Georgia, videoconferencing systems are used for initial court appearances. The systems link jails with courtrooms, reducing the expenses and security risks of transporting prisoners to the courtroom.[54]

The U.S. Social Security Administration (SSA), which oversees the world's largest administrative judicial system under its Office of Disability Adjudication and Review (ODAR),[55] has made extensive use of videoconferencing to conduct hearings at remote locations.[56] In Fiscal Year (FY) 2009, the U.S. Social Security Administration (SSA) conducted 86,320 videoconferenced hearings, a 55% increase over FY 2008.[57] In August 2010, the SSA opened its fifth and largest videoconferencing-only National Hearing Center (NHC), in St. Louis, Missouri. This continues the SSA's effort to use video hearings as a means to clear its substantial hearing backlog. Since 2007, the SSA has also established NHCs in Albuquerque, New Mexico, Baltimore, Maryland, Falls Church, Virginia, and Chicago.[55]

Indonesian and U.S. students participate in an educational videoconference (2010)

Videoconferencing provides students with the chance to learn by participating in two-way communication forums. Because it is live, videotelephony allows teachers to access remote or otherwise isolated learners. Students from diverse communities and backgrounds can come together to learn about one another through practices known as telecollaboration[58][59](in foreign language education) and virtual exchange, although language barriers will continue to be present. Such students are able to explore, communicate, analyze, and share information and ideas with one another.

Through videoconferencing, students can visit other parts of the world, including museums and other cultural and educational sites. Such virtual field trips can provide enriched learning opportunities to students, especially those who are geographically isolated or economically disadvantaged. Small schools can use these technologies to pool resources and provide courses, such as in foreign languages, which could not otherwise be offered.

Some benefits that videoconferencing can provide to education include:

• faculty members keeping in touch with classes while attending conferences;
• faculty members attending conferences 'virtually'[60][61]
• guest lecturers brought in classes from other institutions;[62]
• researchers collaborating with colleagues at other institutions on a regular basis without loss of time due to travel;
• schools with multiple campuses collaborating and sharing professors;[63]
• schools from two separate nations engaging in cross-cultural exchanges;[64]
• faculty members participating in thesis defenses at other institutions;
• administrators on tight schedules collaborating on budget preparation from different parts of campus;
• faculty committee auditioning scholarship candidates;
• researchers answering questions about grant proposals from agencies or review committees;
• alternative enrollment structures to purely in-person attendance;
• student interviews with employers in other cities, and
• teleseminars.

Videoconferencing is a highly useful technology for real time telemedicine and telenursing applications, such as diagnosis, consulting, prevention, treatment, and transmission of medical images.[65] With videoconferencing, patients may contact nurses and physicians in emergency or routine situations; physicians and other paramedical professionals can discuss cases across large distances. Rural areas can use this technology for diagnostic purposes, thus saving lives and making more efficient use of health care money. For example, a rural medical center in Ohio used videoconferencing to successfully cut the number of transfers of sick infants to a hospital 70 miles (110 km) away. This had previously cost nearly $10,000 per transfer.[66]

Special peripherals such as microscopes fitted with digital cameras, videoendoscopes, medical ultrasound imaging devices, otoscopes, etc., can be used in conjunction with videoconferencing equipment to transmit data about a patient. Recent developments in mobile collaboration on hand-held mobile devices have also extended video-conferencing capabilities to locations previously unreachable, such as a remote community, long-term care facility, or a patient's home.[67]

Videoconferencing can enable individuals in distant locations to participate in meetings on short notice, with time and money savings. Technology such as VoIP can be used in conjunction with desktop videoconferencing to enable low-cost face-to-face business meetings without leaving the desk, especially for businesses with widespread offices. The technology is also used for remote work. One research report based on a sampling of 1,800 corporate employees showed that, as of June 2010, 54% of the respondents with access to videoconferencing used it "all of the time" or "frequently".[68][69]

Intel Corporation have used videoconferencing to reduce both costs and environmental impacts of its business operations.[70]

Videoconferencing is also currently being introduced on online networking websites, in order to help businesses form profitable relationships quickly and efficiently without leaving their place of work. This has been leveraged by banks to connect busy banking professionals with customers in various locations using video banking technology.

Videoconferencing on hand-held mobile devices (mobile collaboration technology) is being used in industries such as manufacturing, energy, healthcare, insurance, government, and public safety. Live, visual interaction removes traditional restrictions of distance and time, often in locations previously unreachable, such as a manufacturing plant floor thousands of miles away.[71]

In the increasingly globalized film industry, videoconferencing has become useful as a method by which creative talent in many different locations can collaborate closely on the complex details of film production. For example, for the 2013 award-winning animated film Frozen, Burbank-based Walt Disney Animation Studios hired the New York City-based husband-and-wife songwriting team of Robert Lopez and Kristen Anderson-Lopez to write the songs, which required two-hour-long transcontinental videoconferences nearly every weekday for about 14 months.[72][73][74][75]

With the development of lower-cost endpoints, the integration of video cameras into personal computers and mobile devices, and software applications such as FaceTime, Skype, Teams, BlueJeans and Zoom, videoconferencing has changed from just a business-to-business offering to include business-to-consumer (and consumer-to-consumer) use.

Although videoconferencing has frequently proven its value, research has shown that some non-managerial employees prefer not to use it due to several factors, including anxiety.[76] Some such anxieties can often be avoided if managers use the technology as part of the normal course of business. Remote workers can also adopt certain behaviors and best practices to stay connected with their co-workers and company.[77]

Researchers also find that attendees of business and medical videoconferences must work harder to interpret information delivered during a conference than they would if they attended face-to-face.[78] They recommend that those coordinating videoconferences make adjustments to their conferencing procedures and equipment.

The concept of press videoconferencing was developed in October 2007 by the PanAfrican Press Association (APPA), a Paris France-based non-governmental organization, to allow African journalists to participate in international press conferences on developmental and good governance issues.

Press videoconferencing permits international press conferences via videoconferencing over the Internet. Journalists can participate on an international press conference from any location, without leaving their offices or countries. They need only be seated by a computer connected to the Internet in order to ask their questions.

In 2004, the International Monetary Fund introduced the Online Media Briefing Center, a password-protected site available only to professional journalists. The site enables the IMF to present press briefings globally and facilitates direct questions to briefers from the press. The site has been copied by other international organizations since its inception. More than 4,000 journalists worldwide are currently registered with the IMF.

Video Interpreter sign used at VRS/VRI service locations

One of the first demonstrations of the ability for telecommunications to help sign language users communicate with each other occurred when AT&T's videophone (trademarked as the Picturephone) was introduced to the public at the 1964 New York World's Fair—two deaf users were able to communicate freely with each other between the fair and another city.[79] Various universities and other organizations, including British Telecom's Martlesham facility, have also conducted extensive research on signing via video telephony.[80][81][82]

The use of sign language via videotelephony was hampered for many years due to the difficulty of its use over slow analog copper phone lines,[81] coupled with the high cost of better quality ISDN (data) phone lines.[80] Those factors largely disappeared with the introduction of more efficient and powerful video codecs and the advent of lower-cost high-speed ISDN data and IP (Internet) services in the 1990s.

Significant improvements in video call quality of service for the deaf occurred in the United States in 2003 when Sorenson Media Inc. (formerly Sorenson Vision Inc.), a video compression software coding company, developed its VP-100 model stand-alone videophone specifically for the deaf community. It was designed to output its video to the user's television in order to lower the cost of acquisition and to offer remote control and a powerful video compression codec for unequaled video quality and ease of use with video relay services. Favorable reviews quickly led to its popular usage at educational facilities for the deaf, and from there to the greater deaf community.[83]

Coupled with similar high-quality videophones introduced by other electronics manufacturers, the availability of high-speed Internet, and sponsored video relay services authorized by the U.S. Federal Communications Commission in 2002, VRS services for the deaf underwent rapid growth in that country.[83]

A deaf or hard-of-hearing person uses a Video Relay Service at his workplace to communicate with a hearing person in London (2007)

Using such video equipment in the present day, the deaf, hard-of-hearing, and speech-impaired can communicate between themselves and with hearing individuals using sign language. The United States and several other countries compensate companies to provide video relay services (VRS). Telecommunication equipment can be used to talk to others via a sign language interpreter, who uses a conventional telephone at the same time to communicate with the deaf person's party. Video equipment is also used to do on-site sign language translation via Video Remote Interpreting (VRI). The relatively low cost and widespread availability of 3G mobile phone technology with video calling capabilities have given deaf and speech-impaired users a greater ability to communicate with the same ease as others. Some wireless operators have even started free sign language gateways.

Sign language interpretation services via VRS or by VRI are useful in the present day where one of the parties is deaf, hard-of-hearing, or speech-impaired (mute). In such cases the interpretation flow is normally within the same principal language, such as French Sign Language (LSF) to spoken French, Spanish Sign Language (LSE) to spoken Spanish, British Sign Language (BSL) to spoken English, and American Sign Language (ASL) also to spoken English (since BSL and ASL are completely distinct from each other), German Sign Language (DGS) to spoken German, and so on.

Multilingual sign language interpreters, who can also translate as well across principal languages (such as a multilingual interpreter interpreting a call from a deaf person using ASL to reserve a hotel room at a hotel in the Dominican Republic whose staff speaks Spanish only, therefore the interpreter has to use ASL, spoken Spanish, and spoken English to facilitate the call for the deaf person), are also available, albeit less frequently. Such activities involve considerable mental processing efforts on the part of the translator, since sign languages are distinct natural languages with their own construction, semantics and syntax, different from the aural version of the same principal language.

With video interpreting, sign language interpreters work remotely with live video and audio feeds, so that the interpreter can see the deaf or mute party, and converse with the hearing party, and vice versa. Much like telephone interpreting, video interpreting can be used for situations in which no on-site interpreters are available. However, video interpreting cannot be used for situations in which all parties are speaking via telephone alone. VRS and VRI interpretation requires all parties to have the necessary equipment. Some advanced equipment enables interpreters to control the video camera remotely, in order to zoom in and out or to point the camera toward the party that is signing.

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• Lohr, Steve. As Travel Costs Rise, More Meetings Go Virtual, The New York Times, July 22, 2008.
• Miller, Claire Cain. Logitech Buying a Maker Of Videoconference Tools, The New York Times, November 11, 2009.
• Miller, Claire Cain. Logitech Breaks Into Videoconferencing, The New York Times, November 10, 2009 on line, and November 11, 2009, in print, p. B3. Discusses the acquisition of LifeSize Communications.
• Millman, Howard. The Videoconference as a Bicoastal Pas de Deux, The New York Times, July 12, 2001.
• O'Brien, Kevin. Stranded Travelers Turn to Videoconferencing, The New York Times, April 19, 2010. Article discusses the increased use of videoconferencing due to the eruption of an Icelandic volcano which severely curtailed air travel for several months.
• Ramirez, Anthony. More Than Just a Phone Call; Video Conferencing And Photocopies, Too, The New York Times, September 15, 1993. Discusses the deployment of videoconferencing rooms in several hundred Kinkos locations.
• Shannon, Victoria. Videoconferencing's virtual leap forward, The New York Times, August 29, 2007.
• Sharkey, Joe. A Meeting in New York? Can't We Videoconference?, The New York Times, May 11, 2009 online, and in print on May 12, 2009, p. B6 of the New York edition.
• Vance, Ashlee. Cisco Buys Norwegian Firm for $3 Billion, The New York Times, October 1, 2009 online, and October 2, 2009, in print, p. B7. Discusses the acquisition of Tandberg.
• Wang, Ses Open source tool detects videoconferencing equipment vulnerabilities, Help Net Security, 17 February 2012.
• Wayner, Peter. Jerky Pictures and Sound Are History. Videoconferencing Is All Grown Up., The New York Times, June 16, 2005.

• Adeshina, Emmanuel. In-Person Visits Fade as Jails Set Up Video Units for Inmates and Families, The New York Times website, August 7, 2012, pg. A15 of the New York Edition.
• Bajaj, Vikas. Transparent Government, Via Webcams in India, The New York Times, July 18, 2011, pg.B3. Published online: July 17, 2011.
• Davis, Andrew W.; Weinstein, Ira M. The Business Case for Videoconferencing, Wainhouse Research, March 2005.
• Fairlie, Rik. Skype Puts Video Calls on Your TV, The New York Times, July 2, 2010.
• Hoffman, Jan. When Your Therapist Is Only a Click Away, The New York Times, September 25, 2011, pg. ST1. Also published September 23, 2011 online at www.nytimes.com.
• Miller, Hugh."Videophones: The Real Problem". Archived from the original on 2002-06-16. Retrieved 2002-06-16.{{cite web}}: CS1 maint: bot: original URL status unknown (link), Department of Social Sciences, Nottingham Trent University, June 16, 2002. Discusses social issues related to videotelephony.
• Perlroth, Nicole. Cameras May Open Up the Board Room to Hackers, The New York Times online, January 22, 2012. A version of this article appeared in print on January 23, 2012, on page B1 of the New York edition with the headline: "Conferences Via the Net Called Risky".
• ProAV Magazine. Being There, ProAV Magazine, November 7, 2008.
• Saint Louis, Catherine. With Enough Bandwidth, Many Join The Band, The New York Times, January 10, 2012 (online), January 11, 2012 (in print, New York Edition, pg. A1). Retrieved online January 11, 2012. Synopsis: a look at the pros and cons of videotelephony used for private, individual, music lessons.
• Steinberg, Neil. Dude, Where's My Video Phone?, Forbes.com website, October 15, 2007

• Biello, David. Can Videoconferencing Replace Travel?, Scientific American, March 18, 2009.
• Coroama, V.C., et al. Effects of Internet-Based Multiple-Site Conferences on Greenhouse Gas Emissions Archived 2013-06-03 at the Wayback Machine, Telematics and Informatics, 2011, doi:10.1016/j.tele.2011.11.006
• Pachner, Joanna. The Next Best Thing to Being There, Toronto: The Globe and Mail, October 13, 2009.

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• Schulte, Olaf A. "The Next Best Thing To Being There"—Ein Überblick Zu 25 Jahren Videokonferenzforschung (An Overview of 25 years of videoconferencing research) in: Medien & Kommunikations-wissenschaft, Baden-Baden: Hans-Bredow-Institut, April 2002, pp. 551–570 (PDF, German).