For many users, desktop videoconferencing remains an elusive goal, due to incompatibilities and inconsistent ISDN availability. The barriers are coming down, but slowly. Here's why.
Salvatore Salamone
If you thought videoconferencing was going to drastically reduce your traveling, don't toss out your frequent flyer membership cards just yet.
Despite much promise and promotion, most corporations still aren't communicating via videoconference. And they most likely won't be unless more vendors support interoperability standards, and ISDN becomes more widely available and used.
DVC (desktop videoconferencing) is at a crucial juncture. Currently, the market is small (by most computer industry standards). For example, only 30,000 desktop videoconferencing s
ystems shipped last year, according to the consultancy Personal Technology Research (Waltham, MA), during which time over 18 million PCs were shipped within the U.S. However, several industry analysts see desktop videoconferencing exploding over the next two years and predict that up to 1 million DVC systems may be shipped by 1998.
The reason for such optimistic projections? The marketplace is starting to remedy the lack of interoperability and unavailability of ISDN, two of DVC's biggest stumbling blocks.
On the standards front, progress was made earlier this year when the PCWG (Personal Conferencing Work Group), which is dominated by Intel, finally agreed to support H.320, the ITU-T's standard for videoconferencing. PCWG says the next version of its conferencing software, based on Intel's PCS (Personal Conferencing Specification), will initiate videoconferencing calls using the H.320 call setup procedure. If the DVC system on the receiving end of the call uses PCS, the call will switch and use
the PCS video compression algorithm (Intel's Indeo). Otherwise, H.320 compression algorithms will be used for the duration of the call. Such compliance with international standards will assure users that products from different vendors will have a basic level of interoperability.
However, interoperability won't matter much if ISDN service isn't available in your area. For many DVC users, ISDN offers a good combination of price and performance and seems to be the minimum for decent-quality motion video.
For example, such products as Vistium Personal Video System from AT&T, Communique from InSoft, and Simplicity from Paradise Software all claim 30 frames per second refresh rates when running over ISDN. That's in contrast to the analog-only DVC systems that deliver 15 fps at best (but, more typically, half that rate) when using V.34 modems.
Getting ISDN service is still a problem that varies greatly from region to region. Some regional Bell Operating Companies have been fairly aggressive bo
th in the deployment and pricing of their ISDN services. For example, in the Pacific Telesis region, Pacific Bell is offering residential ISDN service for about $25 per month plus three cents for the first minute of a local call and one cent for each additional minute during prime-time hours.
The Pacific Telesis region has the greatest penetration of ISDN availability--82.6 percent of the telephone lines in this region will have ISDN access this year, according to Bellcore. (ISDN access means that the switches in the central office locations serving customers are capable of supporting ISDN.) That's in contrast to the northeastern U.S., which Nynex serves, where only 49.8 percent of the lines are projected to have ISDN access this year (see
"U.S. ISDN Availability in 1995
").
The lack of ubiquitous ISDN service is creating an opportunity for analog DVC systems. Users are sometimes willing to trade video quality for plain old telephone service's availability and ease of u
se.
Most analog videoconferencing products are collaborative work programs that include a video window on screen. This includes such programs as ShareVision from Creative Labs and Mega-Conference from Alpha Systems Lab that give users videoconferencing capabilities as well as providing file transfer capabilities, an electronic whiteboard for discussions, and the ability to annotate a shared document.
An FCC ruling that took effect earlier this year might impact ISDN pricing. The thrust of the ruling--which is still being debated in Washington, D.C.--is that ISDN subscriber line charges be billed not by line but by each ISDN channel. That means a BRI (Basic Rate Interface) ISDN circuit, instead of being billed as one line, is billed as three circuits. A PRI (Primary Rate Interface) line would be billed as if the customer had 24 circuits. The charges are $6 per month for a business customer's ISDN channel and $3.50 per month for a residential channel. Such charges could increase monthly ISDN charg
es by as much as 14 percent for a BRI user and 50 percent for a PRI user, according to Pacific Bell. It's too early to tell how the new billing scheme will influence the deployment of ISDN.
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ISDN access means that the switches in the central office locations serving customers are capable of supporting ISDN.
Videoconferencing's Achilles' Heels
