Streaming Media - December 2007/January 2008 - (Page 24) let’s work together Let’s Start at the Very Beginning … Back in the early 1990s, videoconferencing systems were used for basic talking head meetings. A meeting might consist of several physical rooms, each run by an operator and filled with participants; participants in each room saw themselves in one monitor (the “vanity monitor” as those of us who operated the rooms called it) and saw participants in another room in a second monitor. The rooms were connected by something called a multipoint control unit (MCU) that allowed the operators in any room to switch the video from room to room (that second screen) depending on who was talking. Some MCUs even used a technology that allowed the video to be The T.120 standard allowed for different content to be sent on different channels, providing the technological switched automatically based on the current framework for most of today’s collaborative computing systems. predominant speaker—someone who, say, spoke for at least 5 seconds. The systems were adequate for talking heads, but the and supplementary tools. In the collaborative computing way the information was presented was substandard, space, a solution was proposed by a company called often consisting of a camera focused on one part of the DataBeam, which was later acquired by Lotus, then table where participants sat. Subsequent systems wrapped into IBM’s SameTime when Lotus was subseadded document cameras, small self-contained units quently acquired. DataBeam’s proposed solution for the that had overhead lights, a lightbox, or a combination of videoconferencing data presentation problem took root, both. Papers would be placed underneath the document grew into a standard, and became, arguably, the camera and displayed intermittently, providing a giant foundation of all collaborative computing systems on image of a paper or acetate, with a hand reaching into the market today, albeit in many derivations. the image occasionally to scratch notes on the paper if The product, FarSite, and the technology, T.120, other participants requested changes to the document. allowed low-bandwidth presentation of graphic images This issue is not that far removed from basic video at very low frame rates—sometimes as low as one frame production for streaming in a corporate environment. every 2 seconds—to be sent on a separate channel from The videographer, who often shoots with a single camera, the main videoconferencing system. The low-bandwidth has to move back and forth between the presenter and scenario, often less than 128Kbps, was necessary since the screen or projected image. And just like rich media bandwidth would need to be stolen from various areas recorders, such as those from Accordent or Sonic of the traditional videoconference. Foundry, which record the video of the presenter and a By 1996, DataBeam’s T.120-based technology had separate copy of the presentation, videoconferencing been licensed by more than 40 software and hardware systems needed to find a way to present PowerPoint and manufacturers and service providers. Companies such other computer graphics tools that were then emerging. as Apple, British Telecom, Cisco Systems, MCI, The biggest problem, though, was bandwidth, as Microsoft, PictureTel, and Sun Microsystems were most videoconferencing systems used T1 or lower data using DataBeam’s toolkits to add real-time collaborative rates, and most video codecs required at least 768Kbps capabilities to products as varied as multimedia microto provide adequate face quality for talking heads. Add processors, desktop operating systems, MCUs, and to this the fact that the MCU was integrated into some videoconferencing applications. FarSite also included lower-cost videoconferencing systems—the ones made document collaboration, based on a product it by Polycom that would later become popular with enterprise released in 1993 that allowed for a radical new tool: the customers—and the bandwidth issue was greatly shared whiteboard. exacerbated since video from all locations in a videoAround the same time, two industry analysts, Andrew conference (the “points” or “nodes”) needed to flow into Davis (who later founded Wainhouse Research) and a single point, which would then switch the video and Christine Perey, provided the videoconferencing indussend it back out. This meant a facility with a T1 that try with interesting research that I had the opportunity to needed to do a four-point call would only be able to use work on. The question, posed to businesspeople and 384Kbps for each node on the call. consumers, asked which of the three tools required As is true in many technological innovations, a small for collaborative computing—video, audio, and data company invents a solution and then licenses it to the collaboration/document sharing—would they prioritize big players, each branding it with its own special name if bandwidth were an issue. The results, which chose 24 STREAMING MEDIA December 2007/January 2008
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