Video conferencing combines the audio and video media to provide both voice communications and television pictures. The images may be graphics, objects, people, room views - virtually anything that can be captured by a television camera. Some video conferencing systems are fully interactive with two-way video and audio. Others provide one-way video accompanied by two-way audio; this type of video conferencing is commonly referred to today as business television.

To be included in the area of teleconferencing, video systems should be interactive; that is, they should allow a two-way flow of information between a minimum of two groups or three individuals at separate locations.

The major advantage of video teleconferencing technology, in comparison to audio or audio graphics, is that it enables people to see others at remote locations as if they were in the same room. For many users, this ability creates a social presence that resembles face-to-face meetings. It also enables participants to see the expressions and physical demeanor of participants, a quality that may be needed for certain situations.

Video conferencing systems can be divided into three basic types:

• Compressed video

• Uses a telephone data circuit (1.5 or 3 megabits)
  
• Rapid movements may be blurred or jerky (Although this is changing as improvements in codecs are introduced)
  
• Transmitted instantly
  
• Usually in color

• Business television

• Uses wide-band, analog transmission via satellite
  
• Full, continuous motion
  
• Uses a separate audio link to provide two-way interaction
  
• Transmitted instantly
  
• Usually in color

• Full-motion video

• Uses a wide-band transmission channel
  
• Full, continuous motion
  
• Transmitted instantly
  
• Usually in color

The technology of video conferencing has progressed through improvements in equipment and transmission services.

Further, the costs for video conferencing - equipment and transmission - have dropped dramatically in the past 18 months, and market trends seem to indicate even more decreases in the future.

This Chapter examines current technologies for video conferencing full-motion video, business television and compressed video. It discusses the equipment, transmission, networks and application considerations that should be made before undertaking video conferencing.

Figure: Video Conferencing Technology Options

Video Conferencing System Options

Video conferencing systems include a range of options. In general, they differ mainly in the types of end-user equipment and transmission channels that are employed. These options include:

User Equipment and Environment:

• Installed video conferencing rooms (private, public or shared).
• Transportable consoles for a meeting or conference room environment.
• Portable equipment for individual room or office.
• Public facility for one-way video reception (occasional-use, ad hoc video).
• Basic components: monitors, cameras, control pad or panel, audio speaker and microphone system.
• Accessories: graphics system (standard or high resolution), large screen video projector, image hard copier, facsimile, videotape recorder, 35mm slide projector and other options.

Transmission equipment:

• Compressed video code (digital).
• Broadcast-quality video (broadband analog).
• Controller or signal processor.
• Encryption system.
• Channel interface.
• Earth station or local access to network.

Transmission Channel:

• Analog or digital.
• Satellite or terrestrial.
• Public, private or shared network.
• Two-way video or one-way video.
• Domestic or international.

Video Codecs.One of the primary distinctions between the types of videoconferencing systems employed today are those using compressed video codecs on a digital transmission channel and those using broadcast-quality video on a broadband analog channel.

Many facilities use video codecs and digital networks. These include private networks dedicated to the user organization and shared networks that serve public and private video conference rooms. A codec reduces the video bandwidth by using a compression technique to eliminate redundant information in the video picture. This picture information can then be transmitted along a data circuit that costs significantly less than a broadband channel. Most codecs operate over a digital data channel called a T1 carrier, with transmission rates ranging from 56 kilobits per second to 1.544 megabits per second or a T1.

In addition to reducing bandwidth, the newest codecs also improve picture quality. Some vendors have incorporated a coding technique called motion compensation to provide better motion and resolution. Motion compensation differs from previous video compression methods in its level of sophistication. One method currently used - interframe coding for conditional replenishment compares the actual changes between two frames of information and transmits those changes. It then transmits only the difference between the predicted frame and the actual frame. Some codecs also offer split screen/dual screen capability for continuous presence video conferencing.

As video codecs have continued to improve with better performance and lower costs, they have had a dramatic impact on the use of full-motion video conferencing, especially when coupled with the increased availability of digital networks and the entry of picture enhancement systems which convert a lower resolution picture to one with a high resolution.

Rollabouts and Transportables. As an alternative to a permanent video conference room with installed equipment, a number of vendors have introduced transportable systems. In a transportable system, the video equipment is integrated into a tabletop, console or rollabout cabinet. It includes one or more cameras, one or more monitors, associated electronics, and control system to display pictures of participants.

Some units also have audio equipment and a graphics camera integrated into the same console as the video. In other systems, the graphics equipment resides in another matching console.

Organizations considering implementing video conferencing can reduce the cost of custom conferencing rooms by going to a rollabout system. These are built at a factory and can be brought into existing conference rooms. These systems are reasonable alternatives to rooms requiring full design and engineering work. Whether an organization wants to with an integrated video conferencing system or a totally redesigned and constructed video conference room, is a matter of organizational style.

A variety of mediums are available to transmit video conferences. These transmission mediums include land-based (terrestrial) telephone lines, satellite, fiber optics, cable and microwave.

Capabilities of these mediums are packaged by communication providers as unique services offering the user options for video conferencing transmission. These services exist in two forms: Digital data circuits and analog video channels.

Digital Data Circuits.Digital data circuits for transmission of compressed video images range from 56 kilobits per second (kbps) to DS3 circuits that transmit 45 Megabits per second (Mbps). Due to the high cost of DS3 circuits, most video conferencing is done at 56 kbps to 1.544 Mbps or T1. There is a direct relationship between video performance and transmission speed; the higher the speed, the better the picture. However, the cost of transmission also increases with speed.

Video codecs digitize and compress the video signal for transmission at various speeds on digital data circuits. For video conferencing, there are three classifications of codecs:

Low bandwidth codecs operate in the range below 384 kbps.

High bandwidth codecs commonly operate above 384 kbps and up to multiples of T1 (1.544 Mbps).

(3) DS3 codecs provide broadcast or industrial quality video at 45 Mbps.

Codec vendors offer a range of product options with a variety of features and costs within this family of classifications.

An important factor of digital data circuits is that they are available as a dedicated or metered service. A dedicated channel provides service on a 24-hour basis to a point or points on a network, while the metered service is available as needed through reservations or on a dial-up basis. Dedicated digital circuits are normally provided as leased lines (terrestrial or satellite-based) for private network use.

Terrestrial services are available through communication vendors to most major U.S. cities. Access and interconnection is provided through copper wire, fiber optic or microwave technologies.

Satellite communication vendors provide access to remote locations as well as service to most major U.S. cities. The majority of satellite-based digital services today use VSAT (Very Small Aperture Terminal) technology. VSATs use small antennas (1.8 meter) to transmit and receive signals relayed via satellite.

Analog Video Channels. Analog video channels (6.5 MegaHertz) for video conferencing provide one-way transmission for point-to-point or point-to-multi point applications. Any one of the transmission mediums - terrestrial telephone lines, satellite, fiber optics, cable or microwave - can be used to carry the analog video signal, however, satellite is the most commonly used.

The transmission of analog video does not require the use of a video codec but satellite transmission equipment is required. An uplink is necessary to initiate the signal to remote locations; satellite downlinks at remote locations are needed to receive the video signal. Uplinks and downlinks can be permanent or transportable facilities.

Analog video channels are available through major satellite companies such as GTE Spacenet, Hughes Communications, and AT&T. Other companies (e.g., EDS, Keystone Communications, Private Satellite Network, Satellite Network Systems and several others) resell analog satellite services offering value added services for networking and production of video conferences. Called ad hoc or special event conferencing, this is one of the fastest growing segments in the teleconferencing industry.

Because satellites are the most commonly used medium for analog video conferencing, a discussion of their capabilities is appropriate.

Satellites. Satellite signals are transmitted on either the C-band or Ku-band frequency. Of these two options, many corporations prefer Ku-band over C-band because there is more available time on Ku-band and smaller receiving dishes are needed which means they are not only easier to install and more portable but are also less expensive.

A typical C-band frequency is 6/4 gigahertz, while the transmission speed of Ku-band is 14/12 gigahertz. Most business television networks are carried on the C-band frequency. With Ku-band, a relatively new and popular development has been to use it to relay signals to VSATs (Very Small Aperture Terminals) located on a user's premises.

Today, there are a number of network options available to video conference users. These take the form of switched digital networks, such as the Integrated Services Digital Network (ISDN) or Local Area Networks (LANs), or satellite networks that can be private, public or used on "as needed" basis for ad hoc or special event video conferences. In this next section, we will examine switched digital networks and the availability of satellite networks for video conferencing.

Integrated Services Digital Network (ISDN). Since the late 1970s, local public telephone companies and long distance network providers around the world have been upgrading their networks from using analog to digital switching and transmission techniques. These changes have been accompanied by the development of new international standards - ISDN, the Integrated Services Digital Network. Under ISDN, the public telephone network will offer new telecommunications capabilities to telephone users worldwide. The change from POTS - plain old telephone service - to ISDN is like switching from a Model-T to an F-16 jet fighter. The government's FTS 2000 system is an ISDN and will provide these advanced capabilities of being able to integrate video conferencing at various transmission speeds and picture quality.

As a digital network, ISDN has data, voice, and certain types of image transmissions integrated on one telephone line. For example, ISDN users are able to transmit and receive both data and voice calls on the same line at the same time, instead of requiring two separate lines and a modem. This means that with the integration of ISDN into organizations, video conferencing capabilities will be possible through the telephone network eliminating the need for a separate video system.

ISDN capabilities are made possible by hardware and software at the telephone company's central office switch and an organization's premise equipment that divides a single telephone line into two different types of communications channels. The "B." or bearer channel, is able to transmit voice or data at rates of 64 kbps, significantly faster than existing rates of 300 to 9600 bits per second with modems. The "D," or data channel, is used to send signal information to control the B channels and to carry packet-switched digital data.

Two interfaces to ISDN capabilities have been defined so far: basic rate and primary rate. The basic rate interface provides two B channels and one D channel (at 16 kbps) for each telephone line, and is therefore referred to as "2B+D." Basic rate provides a total transmission rate of 144 kbps (two channels of 64 kbps and one channel of 16 kbps) - more than 12 times existing data transmission rates. Each basic rate line is capable of supporting two voice devices and six data devices (e.g., computers and facsimile machines), any two of which can be operating simultaneously.

The primary rate interface offers 23 B channels and one D channel of 64 kbps (also called "23B+D") carried over two pairs of copper wires, offering users a total capacity of 1.544 million bits per second - approximately 150 times as much as regular telephone.

In the future, additional levels of ISDN service will be defined. Broadband ISDN, made possible by fiber-optic cable, will transmit data at speeds beyond 100 million bits per second, for such applications as full-motion color video and high-speed, high-resolution facsimile.

While the B channels increase the total transmission capacity, by offering both higher transmission rates and more channels on each line, the D channel brings new capabilities to the network. D-channel signaling permits single-button access to a number of telephony features, such as call waiting, that may require several keystrokes. In other applications, D-channel signaling can be used to break down and coordinate high-volume network data transmissions, for example, those that would be needed to transmit video conferences.

The all-digital ISDN offers inherent advantages over existing analog systems:

The most obvious benefit is greatly increased speed, which slashes costly transmission time. Transmission which required hours can now be accomplished in seconds.

ISDN digital accuracy minimizes re-transmissions caused by errors. Transmission is clean, eliminating bottlenecks that can cause such problems as high error rates.

The ISDN signaling channel greatly increases customer control of their networks. Moves and changes of both voice and data equipment are simplified to save time, dollars and headaches. Customers simply unplug, move and plug in, reconfiguring their networks based on need, time of day and other factors.

Not only can ISDN users move their equipment around at will within a building, but they can take it across town, across the country or around the world.

Integration of voice, data and image traffic offers significant savings in wiring expense. A single pair of voice wires is usually already at each user location, so no separate networks and special cable are needed. There is no need for new ducts or overcrowding of present ducts. Nor is there a need to call the local phone company to install a private line for temporary use. ISDN terminal adapters will work with existing equipment to allow gradual replacement of in-place investment and enable communication with non-ISDN locations. The common denominator of all these benefits is more efficient use of the telecommunications network. It is important to remember, however, that ISDN services will not be universally available thereby limiting the usefulness of many of its special features.

Another type of network that impacts the use of video conferencing is called a Local Area Network, the LAN.

Local Area Networks (LANs). LANs are private, digital telecommunications networks carrying voice, video, data and other communications among desks or work stations in a specific area. LANs serve as a "superhighway" that allows primarily personal computers to break out of isolation and talk to each other. A LAN does this by offering both the communications connections and the network resources to cluster PCs together into a minicomputer-like system for local office operation. A local network also provides the necessary doorways that allow such PC cluster systems to interface with other remote LANs, as well as with the firm's mainstream information processing systems.

A LAN would typically be used for video conferencing in a desk-to-desk environment. And, as trends indicate, we are beginning to see more products being introduced that are integrating video conferencing into the personal computer and for the desktop environment.

Ideally, a LAN offers the following capabilities to its interconnected PCs and their users:

Sharing resources.This capability lets you share disk storage, laser printers, communications like video conferencing and other peripheral resources.

Sharing information. A LAN allows you to transfer and share data, files, text and documents among PCs linked to the network. In a video conference context then, other supporting information such as graphs, charts, or text could be shared among the conference participants.

Sending electronic mail. This gives you the ability to write, send and receive electronic mail messages, memos or call slips.

Sharing software and performing group work. A LAN permits you to share software application programs and to work as a group on a task that involves the use of common software (groupware), such as database, word processing or desktop publishing. With video conferencing in an LAN environment, it would be possible for a widely dispersed group to collaborate on a project simultaneously.

Linking to other computers, network and services. This ability lets you link with - and extend the previously mentioned capabilities to - other types of PCs or computers on a local level. For example, you can link IBM or compatible PCs with Apple Macintosh computers, or tie PCs or Macs into minicomputers. You can also tie into external networks, computer systems or information services.

The basis of an LAN is its topology - the physical and logical arrangement of a LAN's cabling and nodes (the points at which PCs and network resource modules, or servers, attach to and access the LAN).

Three topologies are available for stringing a LAN together: linear bus, ring and star.

With linear bus topology, the nodes are arranged in series along a continuous length of cabling. With ring topology, the cabling is formed into a closed loop, or ring, with the nodes arranged along the periphery. With star topology, each node sits at the tip end of cable segments radiating out in a spoke, or star-like fashion, from a central hub control node.

Both bus and ring topologies use broadcasting schemes in which all LAN video transmissions pass through every node in the network. An encoded address lets each node recognize those transmissions that are directed to it.

Each node gains access to the network and captures the right to transmit images, voice or data in one of two ways. It can "listen" to determine whether the LAN is free of other transmissions (carrier sense multiple access) or it can wait until it is passed a token that allows it to transmit.

In star networks, all transmissions pass through and are routed by a central hub controller.

Bus and ring are the most commonly employed topologies in LANs today. Ethernet networks employ a linear-bus topology, whereas token-passing varieties primarily employ rings (hence the term, "token-ring" network).

The file server, which is common to all LANs, acts as the central storage module for the software, applications and files that are to be shared by PCs on the network.

Some smaller, less costly LANS may use the storage facilities of one or more of the PCs on the network by appropriating a portion of their hard disks for server tasks. Most often, however, a LAN will employ one or more dedicated file servers. These are configured either on a PC with a hard disk or on a similar platform designed specifically for server applications.

Larger, more sophisticated LANs may also employ other servers that are dedicated to specific tasks. For example, a server may manage electronic mail distribution within and without the network, or it may handle communications with a mix of different computers.

Other components of a LAN include the "wires in the wall," the physical media that provide the electrical pathways for network transmissions. Such media can range from inexpensive telephone-type twisted-pair wiring to more costly, but higher capacity, shielded-pair, coaxial or fiber optic cabling that can support heavier network transmission loads.

PCs, printers and other LAN modules hook up to the cabling via network adapter interfaces. These hardware adapters, or cards, contain circuitry that conform to the protocol or standards required for all network transmissions.

These adapter cards also come in configurations supporting various speeds (millions of bits per second) under these standards and in versions that can: interface with wiring that ranges from twisted pair through fiber-optic cable.

There is a zero-slot class of local nets that eliminates the need for an adapter and uses the RS-232C interface for the PC. However, such networks are limited in both their transmission capacities and their overall capabilities.

Other network modules include repeaters, bridges, gateways and routers. Repeaters are used primarily in telephone-type twisted-pair networks to extend the physical distance or reach of the LAN. Bridges are used to link different LANs together.

Gateways are terminal-type interfaces that are used to link a LAN into a wide area network or into an external communications network or data service, or with a mini or mainframe computer. (Gateways will be discussed in greater detail in the next segment.) Routers are used in very large networks to determine the optimum pathway to link up with a remote node or another network.

The network operating system (NOS) software makes the LAN work. The NOS controls LAN transmissions and PC access to server resources.

Some network operating systems can provide extensive network management and data security facilities. Others also offer built-in electronic mail services.

NOS software can come either bundled with or unbundled from the LAN hardware. The bundled approach may seem appealing as a single-vendor method of buying and building a LAN on a turnkey basis.

With the integration of Local Area Networks into overall office automation, full-motion video conferencing has become an add-on function and consequently, we are seeing the significant growth of desk-top conferencing through the personal computer.

Gateways. With either LANs or ISDN, it may be critical to access another digital network or an analog network. A gateway provides this flexibility and versatility to any digital network. Simply put, a gateway allows different systems to "talk" to one another. This means users of a digital video network would be able to tap analog broadcast networks or to receive programs from a similar source for occasional programming which might not otherwise be available.

Satellite Networks. Organizations wishing to use video conferencing can choose to install their own satellite networks by developing a private communications network. This type of system requires permanently installed equipment as well as control facilities and studios. Additionally, this approach would require appropriate staffing to operate, maintain and manage it.

Most of the private systems are found in the Fortune 500 largest industrial corporations - Exxon, Ford Motor Company, IBM, ARCO, Dow Chemical, Xerox, Sperry, Westinghouse and others. Other applications tend to be in major financial or insurance companies including firms like Aetna Life and Casualty, Allstate, Bank of America and Liberty Mutual.

Organizations wishing to use video conferencing need not install their own system, however, or for that matter, develop their own communications network. Options are available today to allow users to lease facilities by the hour for video conferences or, in the case where a user owns their own video conference equipment, to link into a shared transmission and facilities network to defray their end-to-end annual costs. Many of these services are available through either major communication vendors or resellers.

One of the fastest growing segments in the area of video conferencing is the ad hoc event that links multiple locations for a specific function. This means that an organization does not need to have their own network, nor be a regular user of video conferencing. Through ad hoc or special event conferencing, they can "buy" video conference services on a one-time basis through vendors providing such services. Providers of these services offer full production, scripting, talent, transmission, facilities and so forth.

An issue related to ad hoc events is that of cost. The pricing of a special video conference event tends to be more expensive than regularly scheduled events over a private network. This is due to the increased cost for planning and producing an event that must work the first time without failure or delay.

Network Considerations. It is important to consider a number of factors as an organization examines video conferencing: the applications; the projected amount of time a system will be used; whether an existing telecommunications system can support video conferencing; the issue of having a private, dedicated system or leasing public facilities on an ad hoc basis. The answer to these questions lies with the organization's applications for video conferencing and with whom they want to conduct business.

Encryption and Security.The broad, expansive reach of satellite transmission provides opportunities for undesired parties, adversaries, competitors and pirates to gather sensitive information. The rapid growth of private networks has raised the level of awareness of the need for protecting information transmitted by satellite.

Essentially, there are two methods of securing video conferencing systems: scrambling and encryption. Scrambling is much less expensive than encryption but is also much easier to compromise or break.

Encryption is an approach of using "electronic" keys to protect information that is digitally encoded. To be effective, the keys must be managed, controlled, protected and distributed to prevent interception by unfriendly parties.

Scrambling, on the other hand, is an analog or digital scheme, where the signal format is altered to obscure the information. Many references simply define scrambling as an analog technique, however, digital signal processing is now also used to change the signal format without encrypting the entire video signal.

For business television, where critical or vital information may be shown graphically, hard encryption of the audio may not be sufficient. The Scientific Atlanta B-MAC approach is currently the approach taken for most of the business television networks today.

The most secure systems for the video image employ digital encryption, but these are at present too expensive for general use. If purely digital techniques are used, a television signal would, after sampling and digitizing, require transmission at about 90 Mbps. Consequently, digital encryption of video signals for satellite broadcast is not used.

Digital encryption is practical for two-way interactive video conferencing using compressed signals. Compressed signal data rates of 384 Kbps to 1.544 Mbps can deliver acceptable picture quality for many users. However, motion is perceptibly distorted from the analog signal. Nevertheless, the digital signal can be hard encrypted with a Digital Encryption Standard (DES) algorithm that is far superior to any scrambling scheme. Manufacturers of video compression codecs incorporate such encryption options.

There are essentially two categories of analog video scrambling in wide use at present. The first category consists of signal reformatting. The second involves manipulation of television picture lines or line translation. In the signal reformatting approach, the video portion of the signal is usually inverted and broadcast with the necessary synchronization pulses removed. Without these pulses, standard television receivers cannot recover the video signal. While it is relatively easy to defeat such a system with a "black box" by re-inserting the synchronization pulses, the digital audio remains secure - which has been sufficient for entertainment television.

To provide greater security, the video signal can be scrambled by manipulating the horizontal lines. In one particularly effective approach, the blanking time is varied on a line-to-line basis from a minimum of zero to a maximum of two times the normal blanking. This line translation, or tame base scrambling system, redistributes the picture information in time, which provides a scrambled picture.

However, the amplitude of the signal in the line is not tampered with. Hence, the original signal can be reconstructed in the descrambler to a high quality picture with no visible or measurable degradation. The scrambling is dynamic in that the patterns are changed every frame.

As a practical matter, this signal cannot be recovered without knowing the random code used by the scrambler. Individual frames might be recovered with I, expenditure of time and money. This scrambling method is used by the Scientific-Atlanta B-MAC system which has been the choice of most of the corporations operating Ku-band networks.

The Scientific-Atlanta system introduces another consideration - a choice between the National Television Standards Committee (NTSC) format, and the Multiplexed Analog Component (MAC) format. Proponents of the MAC format claim that the NTSC format was finalized in 1953 and utilizes an outdated amplitude modulation technique. They claim this is inferior to a format that is explicitly optimized for satellite transmission, particularly for color television received on a Red-Green-Blue (RGB) monitor. However, within the MAC family are four approaches - A, B. C and D-MAC. While B-MAC has been accepted in North America, the French and the Germans have opted for a version of D-MAC that is compatible with European cable systems.

Once again, the value of the information transmitted over the satellite link determines if the physical and communications security is adequate. Although satellite communications provide unique advantages for private networks in customer-premise, point-to-multipoint star networks, they pose unique problems for securing the system. The value of the information transmitted must be weighed against the cost of physical and communications security to select an appropriate approach for protecting it from compromise.

Like audio and audio graphics, a number of factors need to be considered when deciding whether or not to use video conferencing. Technical factors that deal with picture quality or resolution, bandwidth options, and reliability are indeed part of the decision. Choices also need to be made regarding the number of locations or sites that will be included in a video conferencing system; whether or not point-to-point or multi-point is desired; what kinds of facilities and staffing are necessary; what projected and actual usage should be; what value and benefits you anticipate gaining from video conferencing; and, last, but not least, how much a system costs.

Certainly, these choices of technologies, transmission channels, hardware, and costs influence the final decision yet several non-technological factors can be significant deterrents to the adoption of video conferencing. These factors are often overlooked by users, potential users and vendors alike.

These factors are usually referred to as "inhibiting factors." But they can also be seen as "facilitating factors" if viewed as variables leading to successful video conferencing applications. Some of these facilitating factors include: user resistance, ergonomics or human factors, training, the "Hollywood Syndrome," comparisons with face-to-face meetings, travel cost savings, needs assessment, and internal promotion.

Two-way interactive video appears to satisfy most teleconferencing users mainly because two-way video is most like fact-to-face meetings. Even though video conferencing seems to satisfy, however, users still have difficulty accepting the technology.

Users may resist the technology for many reasons. They may fear new technology, desire human contact, feel unfamiliar with the equipment or have misconceptions about video conferencing's purposes. Introducing new technology into a work situation can disorient employees. Often, management purchases a new system that users do not accept simply because they were not consulted beforehand. So, for users to accept a video conferencing system, they must have input into the decision-making process from the beginning.

To diffuse fears and misconceptions, users also must understand how the technology will affect both the organization as a whole and them individually. After taking these steps, users are more likely to accept video conferencing as a unique communications alternative with distinct advantages and disadvantages.

The final goal in overcoming user resistance is to allow users and machines to work harmoniously and effectively together. This is best accomplished by applying ergonomic principles to video conferencing.

Ergonomics studies the interface between humans and technology. It also examines how well a system is designed to meet human needs. If ergonomic principles, or human factors, are applied correctly, then machines and operators will work successfully with each other and productivity will increase. Conversely, if human factors are not adequately considered, productivity is almost certain to decline.

Video conferencing ergonomics begins with vendors at the point of product design. Equipment must be engineered to perform efficiently and to be user friendly. To successfully design a video conferencing room, users and vendors need to address three ergonomics questions.

First; Who Will Use The Room?

A video conferencing room should be designed with maximum flexibility to accommodate diverse needs and personnel. For example, engineers or research and development people may need to exchange blueprints or specifications sheets; upper level executives may require graphs or charts; and marketers may need to send new product photos.

Secondly; What Equipment Will Best Satisfy the Varied Requirements of All Users?

Besides chairs and a table, a video conferencing room requires monitors, cameras, microphones, graphic display capabilities and so forth. In addition, users and vendors must consider the room's environmental features such a lighting, colors, air conditioning, acoustical treatment, and general decor. These decisions may depend on the image a company or organization wants to project. Overall, the typical video conferencing room must have the controlled environment of a television studio but retain the appearance of a conference room.

Another key element in a video conferencing room's design is high quality audio equipment. In video conferencing, a slightly fuzzy picture or imperfectly defined graph will not ruin a meeting. However, the acceptable range in video quality is broader than that of audio. Without crisp audio, meeting participants will lose interest almost immediately.

The Third Question Is:  Where Should Users Place Equipment?

The best method for determining optimal equipment placement is to experiment with different positions. Meeting participants will want to look around a room, move about, and use various objects. To ensure this flexibility, the monitors, cameras and lighting equipment should not be permanently mounted until after experimentation and trial runs.

By testing and experimenting as a simulated video conference or as an actual conference, intended users can get hands-on experience and can provide constructive feedback about the system. In this manner, vendors and telecommunications managers can get a realistic picture of the interface between technology and people and make adjustments.

The final goal of ergonomic considerations is to integrate users into the entire system of video conferencing as naturally as possible. Proper training is the next step in helping users accept video conferencing.

Many organizations invest significant amounts of time and money in starting up a video conferencing system. Many, however, invest far less time and money for proper training and orientation; sometimes this is a critical mistake.

Training is the key step between installation of a video conferencing system and the smooth, daily operation of that system. A well-designed training program is based on ergonomics and human factors and must address user attitudes, equipment, room design and operation of the technology.

Without sufficient training, potential users are more likely to misunderstand video conferencing and reject it as a communications option. However, a well planned training program, backed by an adequate budget, can increase user acceptance and demonstrate an organization's commitment to productive high technology systems.

An effective training program diminishes the technology's mystique. The emphasis should be practical instead of theoretical, with users learning through direct experience. Another important step is creating a program relevant to users' needs. For example, a training program for engineers would be designed differently than one for high level management or a marketing team. Finally, the training should discuss potential problems users may have when they begin using video conferencing.

Another facilitating factor is a phenomenon called "the Hollywood Syndrome." Video conferencing has some obvious parallels with motion pictures and broadcast television; both require cameras, monitors and special lighting. Some companies attempt to model video conferencing meetings after professional television and show business examples; the results are usually strong and polished, slick presentations but weak on interactive communication. Few people are "naturals" at video conferencing. However, a user does not have to imitate a news anchor to successfully communicate information. Through effective training and experience, most users become more comfortable with the medium.

Many video conferencing applications are for business meetings or routine communications. A relaxed, natural meeting style is more likely to facilitate this kind of communication than a slick delivery. On the other hand, a more polished, style-conscious presentation is more appropriate in an ad hoc video presentation where an organization wants to convey a specific image or showcase a product.

One of the strongest objections to video conferencing is that it is not similar enough to a face-to-face meeting. Executives use this objection as a rationale for not adopting the technology. It is also a recurring complaint once the system is installed.

Research indicates that potential users' objections and complaints stem from an anxiety in moving from a known quantity to an unknown one. Face-to-face meetings are "business as usual" and seasoned executives are accustomed to these rules of behavior. But introducing a new communications system changes the ways people traditionally communicate and work.

Change is always a potentially threatening situation. Video conferencing compounds this threat because it removes an executive's sense of control over interpersonal communications.

Users need to perceive the technology as a unique communications tool in its own right and accept it as a routine part of their daily work. This can only be accomplished by thoroughly understanding a systems' advantages and disadvantages.

One of the chief advantages used to justify video conferencing is its potential for saving travel dollars. Travel statistics are simply the easiest quantitative justification for purchasing video conferencing equipment and services. The technology may well produce travel savings but to focus entirely on that fact is a near-sighted and one dimensional approach to video conferencing.

Instead of using a travel savings/cost benefit approach, other more significant benefits of video conferencing should be stressed. Numerous case studies have shown that video conferencing improves productivity, decreases lead time for organizing meetings, allows more people into the decision making process, decreases the length of meetings while increasing their frequency, reduces executive wear and tear, and produces succinct, better-prepared presentations.

Realistic needs assessment and goal-setting will allow video conferencing to be incorporated as an integral element in an organization's communication mix and the way it conducts business.

One of the most important steps for ensuring video conferencing success is to conduct a vigorous, on-going internal promotion campaign. Studies have established a significant relationship between promotion and increase in total hours spent teleconferencing.

An organization can promote video conferencing in a variety of ways: tours through the facility both during and after construction; videotape presentations; articles and photos in company newsletters; informal question and answer sessions followed by hands-on demonstrations.

Ultimately, the most effective video conferencing promotion is upper management's enthusiastic endorsement of video conferencing use. If employees observe management incorporating the technology into their daily routine, they will be encouraged to find appropriate applications for their department's communication needs.

Though experiments with video conferencing were initiated over 50 years ago, the industry has just begun to establish itself in recent years. There have been many reasons for this slow acceptance of video conferencing: inefficient technology; high transmission costs; the inconvenience of traveling to special studios; misunderstandings of the technology's capabilities and purposes, and so forth. Some of these problems have been solved as equipment has improved and costs have dropped.

Some of the factors making video conferencing more attractive to potential users include the need for faster information distribution; an emphasis on productivity and more efficient meetings; the lowering of transmission costs; the production of easy-to-use equipment; and the good track record of ad hoc video conferences. In addition, the dramatic improvements in digital technology, the development of cost effective codecs and the increase in customer-owned satellite systems have fueled greater acceptance of video conferencing. All of these factors and conditions are putting video conferencing on the verge of widespread adoption and use which has been predicted for many years.