HD Video Conferencing
In its purest sense, HD videoconferencing is simply videoconferencing executed at HD resolution. To do this, every part of the transmission chain must be HD capable. The viewing monitors must be HD, providing widescreen (16:9) images at the 1080i (1920 x 1080 pixels) or 720p (1280 x 720 pixels) image standards. The videoconferencing cameras must also be HD capable, although some degree of video compression will likely be acceptable to reduce bandwidth demands.
The video codecs must be capable of passing and receiving HD signals through whatever network is being used. That said, it isn't necessary to use full HD signal rates to achieve a reasonable HD-like experience. For instance, broadcast HDTV is typically 30 frames per second, but the HD videoconferencing standard for full motion video is 24 frames per second; equivalent to a motion picture frame rate. "Reduce the frame rate, and the bandwidth requirement drops from 1 Mbps to 768, 512 or even 384 kbps," Luttinger says. "Granted, the video may look a bit jerky, but the image quality will still be there."
Worth noting: An HD videoconferencing system can communicate with a non-HD videoconferencing system, says Ira Weinstein, senior analyst and partner with Wainhouse Research, a market intelligence firm based in Duxbury, MA. "When the two systems connect, they automatically check each other's capabilities," he explains. "System One says, 'I can do HD; can you?' If System Two says, 'Yes', then they connect at an HD-compatible data rate. If System Two says, 'No', then System One connects at whatever non- HD data rate is acceptable to System Two."
"The concept is what we call 'optimal definition,' " says Sean Lessman, Tandberg's senior director of advanced technology. Tandberg makes a range of cost-effective HD videoconferencing systems, starting at $8,000 for the Centric 1700 MXP. "Working together, the two systems select the frame rate, resolution, and data speed optimally suited for their interconnection."
The bottom line: HD videoconferencing simply represents an upgrade to standard videoconferencing videoconferencing technology, not a radical or necessarily expensive change.
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