True To Life

HDVC came onto the scene two years ago, first announced by LifeSize Communications, yet the products just started to gain solid market traction in late 2006. In the last few months, all of the major 10/18/2007 9:02 PM Eastern

True To Life

HDVC came onto the scene two years ago, first announced by LifeSize Communications, yet the products just started to gain solid market traction in late 2006. In the last few months, all of the major players, including Aethra, Polycom, Sony, and Tandberg, have introduced HDVC systems.

High-definition videoconferencing systems are finally taking hold. HDVC came onto the scene two years ago, first announced by LifeSize Communications, yet the products just started to gain solid market traction in late 2006. In the last few months, all of the major players, including Aethra, Polycom, Sony, and Tandberg, have introduced HDVC systems.

This trend has caught end-users' attention, prompting them to ask tough questions about what HD really means in terms of benefits, costs, and risks. Given this business climate, any AV integrator working with two-way visual communications should know what HD can add to the customer experience — and how it can highlight or detract from any integrator's design skills.

The promise of HD is quite simple: better image quality. Anyone visiting a consumer electronics store can get a quick introduction and demonstration of the advantages of HD. The common HD video image is 1280 x 720p, composed of more than 920,000 pixels per image. A standard videoconferencing system renders images at CIF resolution, or 352 x 288 pixels, about half the resolution of a standard television image. Hence, an HD image at 1280 x 720p provides nine times the pixel count of typical videoconferencing images.

This means viewers can see more details in the image, whether they be fine print, facial wrinkles, or design renderings. They can sit closer to the screen or take advantage of large-screen displays without being distracted by image pixilation. (A detailed account of the mechanics of visual acuity, image resolution, and viewing distance can be found in “Will Telepresence Save Videoconferencing?” in the April 2006 Pro AV.)

HD brings another change as well for videoconferencing users. The display format changes from a 4:3 to a 16:9 aspect ratio. Thanks to the popularity of flat-screen TVs, most people are familiar with this format. In a typical conference setting, the widescreen display has the advantage of reducing or eliminating the need for camera panning, letting more conference participants fit on the screen. High resolution also makes their faces clearer.

Behind the Scenes

Despite these obvious advantages, HDVC comes with a cost. Processing nine times the pixel count every frame means that the compression/decompression engine required for HDVC demands the latest silicon and software. In addition, the conferencing industry moved a few years ago to adopt the H.264 compression standard, which provides far better images than its H.263 predecessor while requiring about 2 1/2 times the processing power. Therefore, today's H.264 HD systems use about 22 times the processing power of earlier systems.

This is an issue all vendors in this space have had to deal with, and most are now supporting HD with all new hardware architectures. For the end user, the situation is quite different. Today's systems require at least 1 megabit/sec (Mbps) bandwidth connections to deliver HD, and most vendors recommend 2Mbps for an experience that handles motion with much smoother results. For the past decade or more, however, the industry standard for room systems videoconferencing has been 384 kbps (or 0.384Mbps). That means users must verify that their LAN and WAN deployments are capable of handling HDVC in the first place.

Savvy integrators and smart videoconferencing buyers will recognize there are two other issues at play when looking at HD systems.

The first is that even at low bandwidths, such as 256 kbps and above, the new videoconferencing systems with their superior processing power offer distinct advantages. Between full HD resolution and standard CIF resolution, the new systems provide a continuum of improved image quality as bandwidth increases. At 512 kbps, many systems support 4CIF resolution — four times the standard resolution, and nearly indistinguishable from HD by many untrained viewers. Wainhouse Research believes many users will opt for this combination as representing the optimal tradeoff between bandwidth economy and image quality.

The second issue is that IP bandwidth continues to become more plentiful and less expensive. Therefore, any enterprise can futureproof its videoconferencing investment by opting for the new systems rather than risk buying SD equipment based on older designs.

What About Telepresence?

Given the recent flurry of HD and telepresence announcements, many end users have been confused. Despite some vendor marketing hype, there is no relationship between the two. Telepresence systems do not have to be high definition, and high-definition systems may not provide a telepresence experience.

This reality raises the question of what exactly is telepresence. By our definition — and one that the industry is increasingly adopting — Wainhouse believes telepresence is “a videoconferencing experience that creates the illusion that the remote participants are in the same room.” This is not to say that a well-designed conference room cannot provide excellent audio and video quality and an overall pleasing experience. However, to create the telepresence illusion, the environment needs to be carefully controlled. Hence, true telepresence vendors and integrators need to provide furniture and wall treatments (colors, fabrics, lighting, etc.) and to control distances between cameras, displays, and seats carefully to create the life-size images and blended environment that make that “same room” immersive experience.

The telepresence marketing thrusts combined with the sales efforts on the part of a few vendors that have excellent access to C-level customers have created a lot of buzz and a few sales. The number of customers that have telepresence systems and are expanding their deployments is impressive. Most telepresence customers to date share some characteristics. They are Fortune 500 companies with several locations that have multiple senior executives for whom the reduction in wear and tear associated with travel more than justifies the per-room investment costs of $200,000 to $400,000.

So far, telepresence rooms appear to be well-received and used heavily. For example, one company bought three systems initially and then expanded to nine systems over a three-year period. Another enterprise has grown to 18 telepresence rooms. Customers seem to enjoy the “concierge” services that make these systems highly reliable from the end-user's perspective as much as the same-room illusion that comes from high-quality audio/video and transparent technology.

However, we have found a backlash inside some companies, where management finds the systems are too expensive and not suited for general purpose meetings. In addition, many videoconferencing managers are questioning whether the new generation of high-definition systems, when integrated with solid, well-placed audio and video peripherals, might deliver much of the telepresence benefit at far lower cost.

Multipoint Videoconferencing

Many video calls today involve more than two endpoints. There are two different architectures used to accomplish calls from three or more locations. In the typical videoconference world, this calls for a video multipoint control unit (MCU), also known as a bridge. In this centralized approach, all endpoints send a signal to the bridge, and the bridge sends a single video output to each endpoint.

Given the bandwidth and processing challenges created by HD, it is no wonder that an HD-capable MCU needs a lot of processing power and massive IP bandwidth to handle multiple inputs. MCUs available today from Codian, Polycom, Radvision, and Tandberg all claim varying levels of HD sophistication. All of the HD products today support voice-activated switching, in which a full-screen video of the active speaker is sent to all participants. In some cases, the bridge may support speed matching, in which each endpoint gets the best possible image it's capable of receiving. In other cases, the MCU may force all endpoints to a lowest common denominator speed. Some of the bridges also support continuous presence, with which the viewer sees a “Hollywood Squares” display (often 2x2 or 3x3) with typically all of the participants in the call shown in smaller squares. Other layouts are also supported, depending on the particular bridge and the number of people in the call.

With telepresence, most of the suppliers have opted for a noncentralized, nontraditional approach to multipoint. A typical telepresence system is composed of multiple cameras and multiple codecs, each of which can make an independent connection. In a one-on-one situation, all three screens of a typical system in London would show all three cameras from New York, for example. In a multipoint mode, the center screen in New York might show London while the left and right screens showed Boston and Sydney, respectively. Each site sees the other three locations on the three screens, but the view of one site would be limited to the central two chairs, typically — or the camera would zoom out to show the center four chairs. Because each connection in a telepresence call might require 4 Mbps bandwidth, most telepresence vendors recommend that customers deploy at least 12 Mbps to support each system.

Impact on AV Integrator

High definition, with its ability to support large screens and full-frequency sound, gives the savvy integrator and room designer opportunities to shine by installing well-thought-out, superior lighting and sound peripherals that support a high-end meeting experience.

Users of HD videoconferencing will appreciate clear, echo-free sound that reduces meeting fatigue, while being able to see the panorama and detail enabled by HD video. In a sense, HD provides an opportunity for value-added AV systems integrators that understand sound and lighting design to differentiate themselves from simple “box pushers.”

On the other hand, telepresence holds a different set of challenges. Some telepresence systems will be sold, installed, and serviced directly by the vendors themselves. Others will move through channels but come with very tight design constraints that leave little room for designer or installer value-add. A few telepresence vendors, however, are leaving many customization details up to their AV integrator partners.

The key issues here are if the AV integrator has the sales contact to close a telepresence deal with the decision maker, and the support team to provide the expected high levels of customer service.

With major IT vendors, such as Cisco and Hewlett-Packard, promoting telepresence, and with videoconferencing industry leaders Polycom and Tandberg getting into the game, the telepresence market is poised for takeoff. CEOs are excited by the prospects, but with their high prices, Wainhouse doubts that true telepresence systems will ever represent more than 1 percent of room videoconferencing unit shipments.

On the other hand, high definition should be viewed as the latest advance in image resolution and a technology that will capture the mainstream. For the videoconferencing world, HD brings two-way, real-time video up to the same performance as high-end television, something the conferencing world has long wanted. While video has progressed over the past decade from SQCIF to QCIF to CIF to 4CIF to HD, it is likely to remain at the HD level for quite some time; this is the resolution supported by commonly available cameras and displays with no enhancements in the consumer space.

Some trends that AV integrators and end users can look forward to are:

  • Migration of HD capabilities down the product lines of the major vendors, even to entry-level products
  • New silicon and software designed into videoconferencing systems to deliver even higher image quality at ever reduced bandwidths
  • The ability of more and more customers to deploy data networks capable of supporting HD video. HD is certain to dominate the videoconferencing market within the next five years.

Andrew Davis is the managing partner with Wainhouse Research in Duxbury, Mass. He can be reached at  

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