Videoconferencing is the conduct of a
videoconference (also known as a
video conference or
videoteleconference) by a set of
telecommunicationTelecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
technologiesTechnology is the making, usage, and knowledge of tools, machines, techniques, crafts, systems or methods of organization in order to solve a problem or perform a specific function. It can also refer to the collection of such tools, machinery, and procedures. The word technology comes ;...
which allow two or more locations to interact via two-way video and audio transmissions simultaneously. It has also been called 'visual collaboration' and is a type of groupware.
Videoconferencing differs from
videophone callsA videophone is a telephone with a video screen, and is capable of full duplex video and audio transmissions for communication between people in real-time...
in that it's designed to serve a conference rather than individuals. It is an intermediate form of
videotelephonyVideotelephony comprises the technologies for the reception and transmission of audio-video signals by users at different locations, for communication between people in real-time....
, first deployed commercially by
AT&TAT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
during the early 1970s using their Picturephone technology.
History
Videoconferencing uses audio and video telecommunications to bring people at different sites together. This can be as simple as a conversation between two people in private offices (point-to-point) or involve several sites (multipoint) with more than one person in large rooms at different sites. Besides the audio and visual transmission of meeting activities, allied videoconferencing technologies can be used to share documents and display information on whiteboards.
Simple analog
videophoneA videophone is a telephone with a video screen, and is capable of full duplex video and audio transmissions for communication between people in real-time...
communication could be established as early as the invention of the
televisionTelevision is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
. Such a videoconferencing antecedent usually consisted of two
closed-circuit televisionClosed-circuit television is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors....
systems connected via
coax cableCoaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
or
radioRadio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
. An example of that was the German Reich Postzentralamt (Post Office) video telephone network set up in Berlin and several other cities from 1936 to 1940.
During the first manned space flights,
NASAThe National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
used two radiofrequency (UHF or VHF) links, one in each direction. TV channels routinely use this kind of videoconferencing when reporting from distant locations. The news media were to become regular users of mobile links to
satelliteIn the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s using specially equipped trucks, and much later via satellite videophones in a briefcase.
This technique was very expensive, though, and could not be used for applications such as
telemedicineTelemedicine is the use of telecommunication and information technologies in order to provide clinical health care at a distance. It helps eliminate distance barriers and can improve access to medical services that would often not be consistently available in distant rural communities...
,
distance educationDistance education or distance learning is a field of education that focuses on teaching methods and technology with the aim of delivering teaching, often on an individual basis, to students who are not physically present in a traditional educational setting such as a classroom...
, and business meetings. Attempts at using normal
telephonyIn telecommunications, telephony encompasses the general use of equipment to provide communication over distances, specifically by connecting telephones to each other....
networks to transmit slow-scan video, such as the first systems developed by
AT&TAT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
, first researched in the 1950s, failed mostly due to the poor picture quality and the lack of efficient video compression techniques. The greater 1 MHz bandwidth and 6 Mbit/s
bit rateIn telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
of the Picturephone in the 1970s also did not achieve commercial success, mostly due to its high cost, but also due to a lack of
network effectIn economics and business, a network effect is the effect that one user of a good or service has on the value of that product to other people. When network effect is present, the value of a product or service is dependent on the number of others using it.The classic example is the telephone...
—with only a few hundred Picturephones in the world, users had extremely few contacts they could actually videocall to, and
interoperabilityInteroperability is a property referring to the ability of diverse systems and organizations to work together . The term is often used in a technical systems engineering sense, or alternatively in a broad sense, taking into account social, political, and organizational factors that impact system to...
with other videophone systems did not exist.
It was only in the 1980s that
digital telephonyDigital telephony is the use of digital electronics in the provision of digital telephone services and systems. Since the 1960s a digital core network has almost entirely replaced the old analog system, and much of the access network has also been digitized...
transmission networks became possible, such as with
ISDNIntegrated Services Digital Network is a set of communications standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network...
networks, assuring a minimum
bit rateIn telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
(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 spaceMedia spaces are "electronic settings in which groups of people can work together, even when they are not present in the same place and time. In a media space, people can create real-time visual and acoustic environments that span physically separate areas...
, are not as widely used today as videoconferencing but were still an important area of research. The first dedicated systems started to appear in the market as ISDN networks were expanding throughout the world. One of the first commercial Videoconferencing systems sold to companies came from
PictureTel Corp.PictureTel Corp was one of the first commercial videoconferencing product companies. It achieved peak revenues of over $400 million in 1996 and 1997 and was eventually acquired by Polycom in October 2001.-History:...
, which had an
Initial Public OfferingAn initial public offering or stock market launch, is the first sale of stock by a private company to the public. It can be used by either small or large companies to raise expansion capital and become publicly traded enterprises...
in November, 1984.
From 1984 to 1989, Concept Communication, Inc. of the United States replaced the then 100 pound, US$100,000 computers necessary for teleconferencing with a patented, $12,000 circuit board which doubled the video
frame rateFrame rate is the frequency at which an imaging device produces unique consecutive images called frames. The term applies equally well to computer graphics, video cameras, film cameras, and motion capture systems...
from 15 frames per second to 30 frames per second, and which was reduced in size to a circuit board that fit into standard
personal computerA personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s. The company's founder,
William J. TobinWilliam J. Tobin is an American entrepreneur, inventor, and business owner known for founding ten different startups since 1968, and securing 15 different patents for products and software. Among the companies he founded and served as CEO and Director of Marketing are PC Flowers, Inc. from 1988,...
also secured a patent for a
codecA codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
for full-motion videoconferencing, first demonstrated at AT&T Bell Labs in 1986.
Videoconferencing systems throughout the 1990s rapidly evolved from very expensive proprietary equipment, software and network requirements to a standards based technology that is readily available to the general public at a reasonable cost.
Finally, in the 1990s, IP (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-SeeMeCU-SeeMe is an Internet videoconferencing client. CU-SeeMe can make point to point video calls without a server or make multi-point calls through server software first called a "reflector" and later called a "conference server" or Multipoint Control Unit...
was developed at Cornell by Tim Dorcey et al. In 1995 the First public videoconference and peacecast between the continents of North America and Africa took place, linking a technofair in San Francisco with a techno-rave and cyberdeli in
Cape TownCape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
. At the
Winter OlympicsThe 1998 Winter Olympics, officially the XVIII Olympic Winter Games, was a winter multi-sport event celebrated from 7 to 22 February 1998 in Nagano, Japan. Seventy-two nations and 2,176 participans contested in seven sports and 72 events at 15 venues. The games saw the introduction of Women's ice...
opening ceremony in Nagano,
JapanJapan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
,
Seiji Ozawais a Japanese conductor, particularly noted for his interpretations of large-scale late Romantic works. He is most known for his work as music director of the Boston Symphony Orchestra and principal conductor of the Vienna State Opera.-Early years:...
conducted the
Ode to Joy"Ode to Joy" is an ode written in 1785 by the German poet, playwright and historian Friedrich Schiller, enthusiastically celebrating the brotherhood and unity of all mankind...
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 usages of the technology started in 1992 through a unique partnership with PictureTel and IBM Corporations which at the time were promoting a jointly developed desktop based videoconferencing product known as the PCS/1. Over the next 15 years,
Project DIANEProject DIANE, an acronym for Diversified Information and Assistance NEtwork, was a very early videoconferencing based community service network created in the United States...
(Diversified Information and Assistance Network) grew to utilize a variety of videoconferencing platforms to create a multistate cooperative public service and distance education network consisting of several hundred schools, neighborhood centers, libraries, science museums, zoos and parks, public assistance centers, and other community oriented organizations.
In the 2000s, videotelephony was popularized via free Internet services such as
SkypeSkype is a software application that allows users to make voice and video calls and chat over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system...
and
iChatiChat is an instant messaging software application developed by Apple Inc. exclusively for its Mac OS X operating system. It has audio, video and screen-sharing capabilities as well as text messaging...
, web plugins and on-line telecommunication programs which promoted low cost, albeit low-quality, videoconferencing to virtually every location with an Internet connection.
In May 2005, the first
high definitionHigh-definition video or HD video refers to any video system of higher resolution than standard-definition video, and most commonly involves display resolutions of 1,280×720 pixels or 1,920×1,080 pixels...
video conferencing systems, produced by LifeSize Communications, were displayed at the
InteropInterop is an annual trade fair for information technology organised by UBM TechWeb. It takes place at four different locations at various times of the year: Mumbai , New York , Tokyo, and Las Vegas...
trade show in
Las VegasThe Las Vegas Valley is the heart of the Las Vegas-Paradise, NV MSA also known as the Las Vegas–Paradise–Henderson MSA which includes all of Clark County, Nevada, and is a metropolitan area in the southern part of the U.S. state of Nevada. The Valley is defined by the Las Vegas Valley landform, a ...
,
NevadaNevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, able to provide 30 frames per second at a 1280 by 720
display resolutionThe display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube , flat panel or projection...
. Polycom introduced its first high definition video conferencing system to the market in 2006. Currently, high definition resolution has now become a standard feature, with most major suppliers in the videoconferencing market offering it.
Recent technological developments by
LibrestreamLibrestream Technologies Inc. is a privately-owned, venture capital backed company based in Winnipeg, Canada. Librestream provides technologies that enable mobile enterprise collaboration....
have extended the capabilities of video conferencing 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 collaborationMobile collaboration is a technology-based process of communicating utilizing electronic assets and accompanying software designed for use in remote locations...
systems allow multiple people in previously unreachable locations, such as workers on an off-shore oil rig, the ability to view and discuss issues with colleagues thousands of miles away.
Technology
The core technology used in a videoconferencing system is digital compression of audio and video streams in real time. The
hardwareHardware is a general term for equipment such as keys, locks, hinges, latches, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts. Household hardware is typically sold in hardware stores....
or software that performs compression is called a
codecA codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
(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
IPThe Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
). The use of audio
modemA modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
s in the transmission line allow for the use of
POTSPlain old telephone service is the voice-grade telephone service that remains the basic form of residential and small business service connection to the telephone network in many parts of the world....
, or the Plain Old Telephone System, in some low-speed applications, such as
videotelephonyVideotelephony comprises the technologies for the reception and transmission of audio-video signals by users at different locations, for communication between people in real-time....
, because they convert the digital pulses to/from analog waves in the audio spectrum range.
The other components required for a videoconferencing system include:
- Video input : video camera
A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in...
or webcamA webcam is a video camera that feeds its images in real time to a computer or computer network, often via USB, ethernet, or Wi-Fi.Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as a video camera...
- Video output: computer monitor
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
, televisionTelevision is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
or projectorA video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...
- Audio input: microphone
A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1877, Emile Berliner invented the first microphone used as a telephone voice transmitter...
s, CD/DVD player, cassette player, or any other source of PreAmp audio outlet.
- Audio output: usually loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...
s associated with the display device or telephone
- Data transfer: analog or digital telephone network, LAN
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
or InternetThe Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
- 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 two kinds of videoconferencing systems:
- Dedicated systems have all required components packaged into a single piece of equipment, usually a console with a high quality remote control
A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...
led 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 projectorA video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...
. There are several types of dedicated videoconferencing devices:
- Large group videoconferencing are non-portable, large, more expensive devices used for large rooms and auditoriums.
- Small group videoconferencing are non-portable or portable, smaller, less expensive devices used for small meeting rooms.
- Individual videoconferencing are usually portable devices, meant for single users, have fixed cameras, microphones and loudspeakers integrated into the console.
- Desktop systems are add-ons (hardware boards, usually) to normal PCs, transforming them into videoconferencing devices. A range of different cameras and microphones can be used with the board, which contains the necessary codec and transmission interfaces. Most of the desktops systems work with the H.323
H.323 is a recommendation from the ITU Telecommunication Standardization Sector that defines the protocols to provide audio-visual communication sessions on any packet network...
standard. Videoconferences carried out via dispersed PCs are also known as e-meetings.
Conferencing layers
The components within a Conferencing System can be divided up into several different layers: User Interface, Conference Control, Control or Signal Plane and Media Plane.
Video Conferencing User Interfaces could either be graphical or voice responsive. Many of us have encountered both types of interfaces, normally we encounter graphical interfaces on the computer or television, and Voice Responsive we normally get on the phone, where we are told to select a number of choices by either saying it or pressing a number. User interfaces for conferencing have a number of different uses; it could be used for scheduling, setup, and making the 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 aren’t 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 Protocols (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.
Multipoint videoconferencing
Simultaneous videoconferencing among three or more remote points is possible by means of a
Multipoint Control UnitA Multipoint Control Unit is a device commonly used to bridge videoconferencing connections.The Multipoint Control Unit is an endpoint on the LAN that provides the capability for 3 or more terminals and gateways to participate in a multipoint conference...
(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 unit, or the MCU unit 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 which are a combination of hardware and software. An MCU is characterised 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:
- A single multipoint controller (MC), and
- 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 don't 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.
Videoconferencing modes
Videoconferencing systems have several common operating modes that are used:
- Voice-Activated Switch (VAS);
- Continuous Presence.
In VAS mode, the MCU switches which endpoint can be seen by the other endpoints by the levels of one’s voice. If there are four people in a conference, the only one that will be seen in the conference is the site which is talking; the location with the loudest voice will be seen by the other participants.
Continuous Presence mode display multiple participants at the same time. The MP in this mode puts together the streams from the different endpoints and puts them all together into a single video image. In this mode, the MCU normally sends the same type of images to all participants. Typically these types of images are called “layouts” and can vary depending on the number of participants in a conference.
Echo cancellation
A fundamental feature of professional videoconferencing systems is
Acoustic Echo Cancellation'The term echo cancellation is used in telephony to describe the process of removing echo from a voice communication in order to improve voice quality on a telephone call...
(AEC). Echo can be defined as the reflected source wave interference with new wave created by source. AEC is an
algorithmIn mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
which is able to detect when sounds or utterances reenter the audio input of the videoconferencing codec, which came from the audio output of the same system, after some time delay. If unchecked, this can lead to several problems including:
- the remote party hearing their own voice coming back at them (usually significantly delayed)
- strong reverberation
Reverberation is the persistence of sound in a particular space after the original sound is removed. A reverberation, or reverb, is created when a sound is produced in an enclosed space causing a large number of echoes to build up and then slowly decay as the sound is absorbed by the walls and air...
, rendering the voice channel useless as it becomes hard to understand and
- howling created by feedback. Echo cancellation is a processor-intensive task that usually works over a narrow range of sound delays.
Problems
Some observers argue that three outstanding issues have prevented videoconferencing from becoming a standard form of communication, despite the ubiquity of videoconferencing-capable systems. These issues are:
- Eye Contact: Eye contact
Eye contact is a meeting of the eyes between two individuals.In human beings, eye contact is a form of nonverbal communication and is thought to have a large influence on social behavior. Coined in the early to mid-1960s, the term has come in the West to often define the act as a meaningful and...
plays a large role in conversational turn-taking, perceived attention and intent, and other aspects of group communication. 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 parallaxParallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
observed by the users. This issue is also being addressed through research that generates a synthetic image with eye contact using stereo reconstruction.
Telcordia TechnologiesTelcordia Technologies, formerly Bell Communications Research, Inc. or Bellcore, is a telecommunications research and development company based in the United States created as part of the 1982 Modification of Final Judgment that broke up American Telephone & Telegraph...
, 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 HouseThe White House is the official residence and principal workplace of the president of the United States. Located at 1600 Pennsylvania Avenue NW in Washington, D.C., the house was designed by Irish-born James Hoban, and built between 1792 and 1800 of white-painted Aquia sandstone in the Neoclassical...
and various other government and military facilities. This technique eliminates the need for special cameras or image processing.
- 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
Latency or latent may refer to:*Latency period , the time between exposure to a pathogen, chemical or radiation, and when symptoms first become apparent...
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 timePing is a computer network administration utility used to test the reachability of a host on an Internet Protocol network and to measure the round-trip time for messages sent from the originating host to a destination computer...
is another major technical requirement for the communication channel for interactive videoconferencing.
The issue of eye-contact may be solved with advancing technology, and presumably the issue of appearance consciousness will fade as people become accustomed to videoconferencing.
Standards
The International Telecommunications Union (ITU) (formerly: Consultative Committee on International Telegraphy and Telephony (CCITT)) has three umbrellas of standards for videoconferencing
ITU
H.320H.320 is an umbrella recommendation by the ITU-T for running Multimedia over ISDN based networks. The main protocols in this suite are H.221, H.230, H.242, audio codecs such as G.711, and video codecs such as H.261 and H.263....
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 of America and Canada.
H.264 SVC (
Scalable Video CodingScalable Video Coding is the name for the Annex G extension of the H.264/MPEG-4 AVC video compression standard. SVC standardizes the encoding of a high-quality video bitstream that also contains one or more subset bitstreams. A subset video bitstream is derived by dropping packets from the...
) is a compression standard that enables video conferencing systems to achieve highly error resilient IP video transmission over the public Internet without quality of service enhanced lines. This standard has enabled wide scale deployment of high definition desktop video conferencing and made possible new architectures which reduce latency between transmitting source and receiver, resulting in fluid communication without pauses.
In addition, an attractive factor for IP videoconferencing is that it is easier to set-up for use with a live videoconferencing call along with
web conferencingWeb conferencing refers to a service that allows conferencing events to be shared with remote locations. Most vendors also provide either a recorded copy of an event, or a means for a subscriber to record an event. The service allows information to be shared simultaneously, across geographically...
for use in data collaboration. These combined technologies enable users to have a much richer
multimediaMultimedia is media and content that uses a combination of different content forms. The term can be used as a noun or as an adjective describing a medium as having multiple content forms. The term is used in contrast to media which use only rudimentary computer display such as text-only, or...
environment for live meetings, collaboration and presentations.
The Unified Communications Interoperability Forum (UCIF), a non-profit alliance between communications vendors, launched on May 19, 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.
ITU V.80: videoconferencing is generally compatibilized with H.324 standard point-to-point video telephony over regular phone lines.
Impact on the general public
High speed Internet connectivity has become more widely available at a reasonable cost and the cost of video capture and display technology has decreased. Consequently, personal videoconferencing systems based on a webcam, personal computer system, software compression and broadband Internet connectivity have become affordable to the general public. Also, the hardware used for this technology has continued to improve in quality, and prices have dropped dramatically. The availability of freeware (often as part of chat programs) has made software based videoconferencing accessible to many.
For over a century, futurists have envisioned a future where telephone conversations will take place as actual face-to-face encounters with video as well as audio. Sometimes it is simply not possible or practical to have face-to-face meetings with two or more people. Sometimes a telephone conversation or conference call is adequate. Other times,
e-mailElectronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
exchanges are adequate. However, videoconferencing adds another possible alternative, and can be considered when:
- a live conversation is needed;
- visual information is an important component of the conversation;
- the parties of the conversation can't physically come to the same location; or
- the expense or time of travel is a consideration.
Deaf, hard-of-hearing-Definition:Deafness is the inability for the ear to interpret certain or all frequencies of sound.-Environmental Situations:Deafness can be caused by environmental situations such as noise, trauma, or other ear defections...
and mute individuals have a particular interest in the development of affordable high-quality videoconferencing as a means of communicating with each other in
sign languageA sign language is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning—simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's...
. Unlike
Video Relay ServiceA Video Relay Service , also sometimes known as a Video Interpreting Service, is a videotelecommunication service that allows deaf, hard-of-hearing and speech-impaired individuals to communicate over video telephones and similar technologies with hearing people in real-time, via a sign language...
, which is intended to support communication between a caller using sign language and another party using spoken language, videoconferencing can be used between two signers.
Mass adoption and use of videoconferencing is still relatively low, with the following often claimed as causes:
- Complexity of systems. Most users are not technical and want a simple interface. In hardware systems an unplugged cord or a flat battery in a remote control is seen as failure, contributing to perceived unreliability which drives users back to traditional meetings. Successful systems are backed by support teams who can pro-actively support and 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.
- 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 video conferencing. Technologies such as ADSL have limited upload speeds and cannot upload and download simultaneously at full speed. As Internet speeds increase higher quality and high definition video conferencing will become more readily available.
- Expense of commercial systems - a well-designed system requires a specially designed room and can cost hundreds of thousands of dollars to fit out the room with codecs, integration equipment and furniture.
- Participants being self-conscious about being on camera, especially new users and older generations.
- Lack of eye contact (as mentioned in Problems)
For these reasons many hardware systems are often used for internal corporate use only, as they are less likely to run into problems and lose a sale. An alternative is companies that hire out videoconferencing-equipped meeting rooms in cities around the world. Customers simply book the rooms and turn up for the meeting - everything else is arranged and support is readily available if anything should go wrong.
Impact on sign language communications
- Main articles: Video Relay Service
A Video Relay Service , also sometimes known as a Video Interpreting Service, is a videotelecommunication service that allows deaf, hard-of-hearing and speech-impaired individuals to communicate over video telephones and similar technologies with hearing people in real-time, via a sign language...
, a telecommunication service for deaf, hard-of-hearing and speech-impaired (mute) individuals communicating with hearing persons at a different location, and Video Remote InterpretingVideo Remote Interpreting uses video or web cameras and telephone lines to provide sign language interpreting services, for deaf, hard-of-hearing or speech-impaired individuals, through an offsite interpreter, in order to communicate with hearing persons...
, used where deaf/hard-of-hearing/mute persons are in the same location as their hearing parties
Impact on education
Videoconferencing provides students with the opportunity to learn by participating in two-way communication forums. Furthermore, teachers and lecturers worldwide can be brought to remote or otherwise isolated educational facilities. Students from diverse communities and backgrounds can come together to learn about one another, although
language barrierLanguage barrier is a figurative phrase used primarily to indicate the difficulties faced when people who have no language in common attempt to communicate with each other...
s will continue to persist. 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 to speak with their peers, and visit museums and educational facilities. Such
virtual field tripsA virtual learning environment is a system that creates an environment designed to facilitate teachers in the management of educational courses for their students, especially a system using computer hardware and software, which involves distance learning...
can provide enriched learning opportunities to students, especially those in geographically isolated locations, and to the 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.
A few examples of benefits that videoconferencing can provide in campus environments include:
- faculty members keeping in touch with classes while attending conferences;
- guest lecturers brought in classes from other institutions;
- 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;
- 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;
- student interviews with an employers in other cities, and
- teleseminars.
Impact on medicine and health
Videoconferencing is a highly useful technology for real-time
telemedicineTelemedicine is the use of telecommunication and information technologies in order to provide clinical health care at a distance. It helps eliminate distance barriers and can improve access to medical services that would often not be consistently available in distant rural communities...
and
telenursingTelenursing refers to the use of telecommunications and information technology for providing nursing services in health care whenever a large physical distance exists between patient and nurse, or between any number of nurses...
applications, such as
diagnosisRemote diagnostics is the act of diagnosing a given symptom, issue or problem from a distance. Instead of the subject being colocated with the person or system doing the diagnostics, with remote diagnostics the subjects can be separated by physical distance...
, consulting, transmission of
medical imagesMedical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...
, etc... With videoconferencing, patients may contact nurses and
physicianA physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
s in
emergencyA medical emergency is an injury or illness that is acute and poses an immediate risk to a person's life or long term health. These emergencies may require assistance from another person, who should ideally be suitably qualified to do so, although some of these emergencies can be dealt with by the...
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
OhioOhio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
, United States, used videoconferencing to successfully cut the number of transfers of sick infants to a
hospitalA hospital is a health care institution providing patient treatment by specialized staff and equipment. Hospitals often, but not always, provide for inpatient care or longer-term patient stays....
70 miles (112.7 km) away. This had previously cost nearly $10,000 per transfer.
Special peripherals such as
microscopeA microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
s fitted with
digital cameraA digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...
s,
videoendoscopeEndoscopy means looking inside and typically refers to looking inside the body for medical reasons using an endoscope , an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ...
s, medical ultrasound imaging devices,
otoscopethumb|right|200px|Otoscope - Image of an otoscope thumb|200px|Anatomy of the human ear.thumb|200px|Right tympanic membrane as seen through a speculum.An Otoscope or auriscope is a medical device which is used to look into the ears...
s, etc., can be used in conjunction with videoconferencing equipment to transmit data about a patient. Recent developments in
mobile collaborationMobile collaboration is a technology-based process of communicating utilizing electronic assets and accompanying software designed for use in remote locations...
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.
Impact on business
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
telecommutingTelecommuting or telework is a work arrangement in which employees enjoy flexibility in working location and hours. In other words, the daily commute to a central place of work is replaced by telecommunication links...
, in which employees work from home. 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 video conferencing used it “all of the time” or “frequently”.
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 bankingVideo banking is a term used for performing banking transactions or professional banking consultations via a remote video connection. Video banking can be performed via purpose built banking transaction machines , or via a videoconference enabled bank branch.- Types of Video Banking :Today, video...
technology.
Videoconferencing on hand-held mobile devices (
mobile collaborationMobile collaboration is a technology-based process of communicating utilizing electronic assets and accompanying software designed for use in remote locations...
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 a continent away.
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. Some such anxieties can be avoided if managers use the technology as part of the normal course of business.
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. They recommend that those coordinating videoconferences make adjustments to their conferencing procedures and equipment.
Impact on law
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 AmendmentThe Sixth Amendment to the United States Constitution is the part of the United States Bill of Rights which sets forth rights related to criminal prosecutions...
of the U.S. Constitution.
In a military investigation in
State of North CarolinaNorth Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
,
AfghanAfghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...
witnesses have testified via videoconferencing.
In Hall County, Georgia, videoconferencing systems are used for initial court appearances. The systems link jails with court rooms, reducing the expenses and security risks of transporting prisoners to the courtroom.
The U.S. Social Security Administration (SSA), which oversees the largest administrative judicial system in the world, under its Office of Disability Adjudication and Review (ODAR), has made extensive use of video teleconferencing (VTC) to conduct hearings at remote locations. In FY 2009, SSA conducted 86,320 VTC hearings, a 55% increase over FY 2008. In August 2010, the SSA opened its fifth and largest video-only National Hearing Center (NHC), in St. Louis, Missouri. This continues 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, Illinois.
Impact on media relations
The concept of
press videoconferencingPress videoconferencing is the process and concept of organizing an international press conference using videoconferencing over the Internet....
was developed in October 2007 by the PanAfrican Press Association (APPA), a Paris France based
non-governmental organizationA non-governmental organization is a legally constituted organization created by natural or legal persons that operates independently from any government. The term originated from the United Nations , and is normally used to refer to organizations that do not form part of the government and are...
, to allow African journalists to participate in international press conferences on developmental and
good governanceGood governance is an indeterminate term used in development literature to describe how public institutions conduct public affairs and manage public resources in order to guarantee the realization of human rights. Governance describes "the process of decision-making and the process by which...
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 to the speaker.
In 2004, the
International Monetary FundThe International Monetary Fund is an organization of 187 countries, working to foster global monetary cooperation, secure financial stability, facilitate international trade, promote high employment and sustainable economic growth, and reduce poverty around the world...
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.
See also
- List of video telecommunication services and product brands
- Media phone
The media phone represents a new category of broadband multimedia device that has the potential to become the 4th screen in the home, complementing the PC, TV, and mobile phone handset.- Features :...
- Mobile collaboration
Mobile collaboration is a technology-based process of communicating utilizing electronic assets and accompanying software designed for use in remote locations...
- Mobile VoIP
Mobile VoIP or simply mVoIP is an extension of mobility to a Voice over IP network. Two types of communication are generally supported: cordless/DECT/PCS protocols for short range or campus communications where all base stations are linked into the same LAN, and wider area communications using...
- Press videoconferencing
Press videoconferencing is the process and concept of organizing an international press conference using videoconferencing over the Internet....
- Teleconference
A teleconference or teleseminar is the live exchange and mass articulation of information among several persons and machines remote from one another but linked by a telecommunications system...
- Telecollaboration
Telecollaboration refers to a set of software technologies that enable the integration and extension of personal desktop collaboration into high definition videoconferencing solutions....
- Telepresence
Telepresence refers to a set of technologies which allow a person to feel as if they were present, to give the appearance of being present, or to have an effect, via telerobotics, at a place other than their true location....
, for high-end videoconferencing
- US-Soviet Space Bridge
The US-Soviet Space Bridge was a series of experimental, international telecasts between Soviet and U.S. viewers, performed by group of communication enthusiasts during late Cold War era...
- Visual Communication
Visual communication as the name suggests is communication through visual aid and is described as the conveyance of ideas and information in forms that can be read or looked upon...
- Videophone
A videophone is a telephone with a video screen, and is capable of full duplex video and audio transmissions for communication between people in real-time...
, for basic units and their point-to-point use
- Videotelephony
Videotelephony comprises the technologies for the reception and transmission of audio-video signals by users at different locations, for communication between people in real-time....
, an overview on the parent article
- VROC
Virtual Researcher on Call is a Canadian educational program administered by Partners in Research. The program connects students with researchers, scientists, and experts in the health and natural sciences, technology, engineering, and mathematics fields through mentoring and video conferencing...
(Virtual Researcher on Call)
- Webcam
A webcam is a video camera that feeds its images in real time to a computer or computer network, often via USB, ethernet, or Wi-Fi.Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as a video camera...
Further reading
- Biztech2 Actis Launches Mobile Videoconferencing Solution Biztech2.com website, August 25, 2009. Retrieved November 19, 2009.
- Davis, Andrew W. & Weinstein, Ira M. The Business Case for Videoconferencing, Wainhouse Research, March 2005.
- Hoffman, Jan. When Your Therapist Is Only a Click Away, New York Times, September 25, 2011, pg. ST1. Also published September 23, 2011 online at www.nytimes.com.
External links