Tzu-hui Wu (Editor: Scott Partridge)

Desktop video conferencing is one of the most electrifying applications to emerge from multimedia technology. It combines the instant connectivity of your phone with visual impact of real-time video. The desktop PC-based video conferencing promises to revolutionise the workplace we used to work in.

Desktop video conferencing (DVC) is a more up-close and personal technology when compared to room-based video conferencing. DVC is a few-to-few or one-to-one technology. It requires two very capable desktop computers with special add-ons. However, many corporations, such as AT&T, Intel, Creative Labs, etc., have their own techniques to implement this technology. Not all of the products follow the same standards (T.120, H.320, H.324, H.325, H.323). H.320 technology is the most popular. Additionally, there is CU-SeeMe technology that is software developed at Cornell University.

H.320 TECHNOLOGY

This high-end DVC equipment consists of one or two boards, a video camera, a microphone, and the associated software installed in a powerful desktop computer. One board is a modem board that lets the computer connect to a special ISDN telephone line that gives four to ten times the bandwidth of a typical modem attached to a voice-grade phone line. The second board is a "codec" board, which stands for " compression-decompression" and simply means that the board will compress the outgoing video signal and decompress the incoming video signal.

To use a properly configured H.320 set-up, associated hardware has to be attached to the computer, including the video camera, and dial a special ISDN number. Once the call is connected, those on the other end of the call appear in full color, with good resolution, in a quarter-screen window on the monitor. One can converse with those on the other end of the videoconference and work on a shared white board. In some arrangements, both end of the videoconference can even share software, such as a shared "whiteboard" area that participants can mark up and collaborate on applications such as a slide presentation or a spreadsheet.

CU-SEEME TECHNOLOGY

CU-SeeMe software, developed at Cornell University, provides inexpensive DVC for the masses. To make use of CU-SeeMe software, one needs to be on the Internet, attach to a ssrver at http:// cu-seeme.cornell.edu and downloads (FTP or Fetch) the software. The next step is to buy a black-and-white "QuickCam" miniature video camera and attach it to the serial port on the computer. The remaining piece is a modem (at least a 28.8 baud) connected to an Internet service provider that will assign the user an IP (Internet Protocol) address, which people on the other end of the conference will need in order to call the user. But the image of people on the other end on the screen is in a black-and-white window that is smaller and movement is more jerky than the H.320 setup window.

Here is a table about the DVC technology products:

Standard features:

*including camera, AV connectors, Share Software and network interface.

** when user purchases either local ISDN Service from a participating LEC or long distance ISDN Service from an IXC, the price drops to $1499.

Hardware & software features:

* The advantage of the H.320 standard is that it will allow systems purchased from different vendors to interoperate.

DVC has great potential for bringing people together as a meeting without walls. Except the major function applied the workplace, DVC is also a powerful tool on distance learning. As the Internet was borne from the academic world, DVC is, and will be widely used for distance learning.

Besides distance learning, DVC applies to banking as well. It helps Savings Bank of Manchester meet the need of its customers now and in the future. For this community bank located in Connecticut, they are adapting for the future by using video conferencing technology. They are exploring ways to improve the internal communication among their 23 bank branches, as well as external communication between employees and customers. Besides, they plan to use video conferencing technology in conjunction with the bank's ATMs.

Another future application is that video conferencing enables parents of hospitalized infants to see and talk to their babies and review their progress with doctors even when they can't be at the hospital. DVC has the interest of users and organisations everywhere with benefits and applications increasing when more people have access to this technology over the Internet.

DVC lets co-workers in different locations collaborate on spreadsheets and reports. It also can save money since an overnight cross-country trip running $1000 to $1500 in airfare, lodging, and other expenses. Furthermore, the cost of time lost dashing through airports and waiting in taxi lines is unavoidable. So compared the cost of meeting in person, the time and money saving DVC can provide makes more and more corporations apply DVC to their conference with clients or business partners far away from them.

In a common desire to make DVC over the Internet a reality, Microsoft and Intel have been promoting the International Telecommunications Union (ITU) and Internet Engineering Task Force (IETF) standards that allow point-to-point, multipoint, or multicast communications over the Internet.

With the popularity of ISDN, DVC will be more and more popular within every household. But ISDN still has problems, such as its low bandwidth. Telephone companies are launching to increase the speed of data transmission. The technical breakthrough of bandwidth will attract more people to use DVC as one of their communication ways with others. Besides, the improvement of data compression technology will be another reason for take more users into the world of DVC.

The future seems to be very bright. Can you imagine a world that DVC are widely used in all the families and offices? This is a whole new method to communicate with each other. With the decreasing price of desktop PCs, PC-based video conferencing is more feasible than the room-based video conferencing. In the near future, the use of DVC can be widely expanded. In the long term, DVC can be part of personal communication systems (PCS).

Bundy, D. ‘Video conferencing: into the future’: online. Available HTTP: ¡Error!Marcador no definido. (8 March 1998).

Desmond, M. (1995) ‘Video conferencing: coast to coast and face to face’, PC World, March 1995.

Horn, R.V. (1996) ‘Power tools, sorting it out: distance learning, video conferencing, and desktop video conferencing’, Phi Delta Kappan, May 1996.

Pfeiffer, M.P. ‘Video to the desktop: the case for switched routing in multimedia intranets’: online. Available HTTP: ¡Error!Marcador no definido. (8 March 1998).

‘PictureTel videoconferencing helps Savings Bank of Manchester meet the need of its customers now and in he future.’ [http://www.picturetel.com/ manchester.html] 29 March 1998.

‘PictureTel videoconferencing links parents with their hospitalized infants.’ [http://www.picturetel.com/press73.html] 29 March 1998.

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