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Feasibility

In this section we focus on the feasibility of video-conferencing because video-conferencing is the most expensive of the technologies needed to support distance communication over digital networks. While video-conferencing is synchronous, the technical requirements for asynchronous delivery of on-demand stored video are similar.

On-demand, ``anytime'', ``anywhere'', video-conferencing has long been considered the next great step for both networking and telephony. The difference now is that both cost and technology are coming within reach of the mainstream business market, educational institutions, and users of advanced technology.

For example, David Brown [2] states that bidirectional reasonable-quality video need not take up more than 400Kb/s. At the same time that advances in networking technology are providing ever-increasing bandwidth from the backbone (ATM [6], Gigabit Ethernet [4]) to the desktop (100 Mb/s FastEthernet cards can be obtained for under $100 retail), advances in encoding standards, hardware, and software for video and audio transmission are reducing the load for multimedia transmission and reception on both the networks and the processors. These advances are encouraging commercial suppliers to provide encoding and decoding equipment that can use the existing Internet for video and audio transport.

While current prices for high-bandwidth long-distance communication are still fairly high, they already compare favorably with commercial travel when savings of time and travel expenses are taken into account, especially for short or frequent interactions. Without quoting specific prices, it is sufficient to point out that 400Kb/s is only about 6 times as much bandwidth as is required to carry a regular (audio) telephone call, and in the long term prices can be expected to become correspondingly low. For higher quality video, the price would be correspondingly higher, but we note several trends that would tend to keep the price in check:

The future is ultimately unpredictable, but there is every reason to believe that these trends will continue.


next up previous
Next: Asynchronous and Distance Education Up: Asynchronous and Distance Communication Previous: Introduction
Edoardo S. Biagioni (Edo)
1999-08-02