TECH FOCUS: Video (and more) to the Desktop
In delivery of video to the desktop, the challenge has been finding an innovative alternative to bandwidth-hungry files clogging the local area network. Such a solution, announced last spring, is about to enter the marketplace.
Objective Communications (Chantilly, VA) has developed a system that uses existing telephone lines within the enterprise to deliver video without interfering with phone calls or other uses of the telephone lines such as data transmission. The development process took several years, but the product is now poised to change the balance of power in video delivery and perhaps other desktop applications as well.
The system, referred to as the Enterprise Video System (EVS), has three primary desktop video applications:
* two-way video conferencing,
* transmission of television programming,
* retrieval of stored video files.
The EVS has three components--a broadband switch (EVS-50), a "VidModem" connected to the PC, and software called the VidPhone interface that is installed on the PC. The switch accepts input from a variety of external sources, including integrated services digital network (ISDN), asynchronous transfer mode (ATM), T1 lines and coaxial cable. It works with private branch exchange (PBX), Key Telephone Systems (KTS), Hybrids or Centrex Telephone Systems. It also works with single- or multi-line telephones and display phones. Up to 50 users can be served with each EVS-50 switch, and multiple switches can be employed to scale up the system.
Within the enterprise, uncompressed video is delivered over the phone line to the desktop. When distributing to wide areas, compressed video signals are sent over the ISDN, ATM, T1 and other lines.
Other solutions for delivering video to desktops are available, including sending it over the network (subject to the violent objections of network administrators) or over ISDN lines to each PC. The latter solution is non-trivial, entailing running new lines, installing ISDN communication boards in the PC and coder-decoders (CODECs) as well. Upgrading requires replacing each PC board.
The EVS dodges all those requirements by using the phone lines that are already present in the office, thereby avoiding the network and the need to run new lines. Upgrading would be done at the switch, not at each PC, since no boards are added to the computers. "What makes this technology so compelling is that the infrastructure is already there," said Jerry Stangohr of Capitol Securities Management (McLean, VA). "Moreover, Objective Communications owns far-reaching patents that protect anyone else from bringing data in over a PBX system." The company has been granted more than 50 patents related to the technology.
But how does it really work?
Despite being fortified by a veritable phalanx of patents, Objective Communications is reticent about revealing the technical details. At the heart of the system is digital signal processing technology that makes use of previously unused capabilities of the twisted pair phone lines. It does so using a frequency modulated (FM) signal.
Depending on the quality of the twisted pair wiring, uncompressed video can be sent either 1,250 feet (Category 3) or 2,500 feet (Category 5 wiring). In either case, nothing more than the standard, unshielded wiring is required. "This is a very elegant solution," said Traver Kennedy, an analyst for the Aberdeen Group (Boston), a market research and strategic planning firm.
Some function cards in the system are:
* NTSC TV tuner board, which provides television and stereo audio to the EVS-50 switching system;
* ISDN CODEC, which provides two independent H.320-compliant video conferencing systems and allows WAN connectivity at rates up to 384 Kbps to H.320 terminals outside the EVS;
* ATM CODEC, which provides full-motion video, stereo audio, and high-speed data to remote EVS systems over an ATM connection;
* conference board, which allows up to 10 users to "meet" in a conference mode and share video, audio and data.
George Essex of Applied Quality Communications (Oxon Hill, MD), a VAR and systems integrator, is enthusiastic about the product. "The switch-to-switch configuration connected by an ATM line is optimal for wide area communications; video comes through in real time and is much smoother than ISDN video."
Because the system is not yet on the market, only demonstration applications are in place. In one of the demo applications being conducted by Vivid Resources (San Diego), a military facility is using the EVS to view a helicopter pad that is out of visual range of the current control tower. Clearly, the EVS has many potential uses in video conferencing, transmission of programming and retrieval of video files.
In one potential scenario, a government policy analyst who needs a news update from CNN continues working while a small window containing the broadcast appears on screen. The CNN signal can go into the EVS-50 switch via coaxial cable or satellite; it is then sent over the phone lines to the desktop. Since the EVS makes no significant demands on the computer's CPU, performance is unimpaired. And the small window is a convenience, not an inherent limitation; the size can be altered to full screen for dedicated viewing.
In another situation, a user wanting to view video stored on a server (which can be a hard drive, a jukebox or other storage) selects the appropriate menu item, and the video is sent to the desktop. The video is in digitized form on the server; it goes through the EVS-50 switch and is sent over the phone line.
Finally, a trainer in a remote location can speak to his or her students and also use the whiteboard capability of the system to write notes on the class material. Training and distance learning represent prime applications for video-intensive delivery.
Two projects close to implementation by Vivid Resources relate to medical applications. In one, a van with a satellite uplink will make the rounds on an Indian reservation, providing video to a hospital for real-time medical diagnosis. In another, a camera and display terminal will be placed at the bedside of severely burned children in a San Francisco Bay area hospital and in their parents' homes. "We will be creating a virtual life for these children," says Vivid's Seth Hoerth, who adds, "The medical applications of this technology are very compelling."
Are there video applications that do not mesh well with this system? Yes. The EVS is not a good solution for delivering video that is part of a computer application such as a multimedia CD-ROM. With the disc running on the PC, integration of video from the EVS is theoretically possible, but not practical.
The rest of the story
Little mentioned in the flurry of press releases and articles about the technology is another aspect at least as valuable as the video side, that of file transfer and application sharing. Those capabilities allow the following scenario:
An employee of a company based on the East Coast wants to discuss a report with an employee in the West Coast field office. He brings up a Windows-based word processor and sends the file to his colleague using the EVS-50 system's file transfer option. Both users see the file on their respective screens. The West Coast user recommends a change in wording and makes the change, which the East Coast user sees in real time and sends the file back to the originator, where it is stored on the hard drive. And all along, the two have been talking on the same phone line that is carrying the data back and forth.
Other technologies, including ISDN, provide options for sending files, of course, for sharing applications and conducting multiple operations on the same line. However, the other options also require substantial investment in infrastructure to allow those capabilities.
Distribution and pricing
Sprint and Bell Atlantic have announced that they will distribute Objective Communications' video networking products. Bell Atlantic has a 10-year contract with the Department of Defense to upgrade its telecommunications capabilities, and Objective's video products will be available through that contract. Sprint, which built and operates the only all-digital fiber optic network in the United States, has also decided to market the product.
Objective Communications notes that it is not an "off-the-shelf" solution and that distributors must be trained to install and service the equipment. The value-added resellers for the EVS will be trained by Objective Communications.
The system costs about $3,000 per desktop, depending on the capabilities chosen. As with many new technologies, the cost is likely to decline as sales volume increases.
The telecommunications companies have long wanted a more dominant role in the information business. Objective Communications' EVS offers the potential for a revolution in the way that video and other data is distributed. *
Judith Lamont is director of research at the Special Interest Group for CD Applications and Technologies (SIGCAT) Foundation, 703-435-5200, E-mail firstname.lastname@example.org.