Face to Face

Dec. 1, 2005
AV conferencing technology connects communications

While no product can replace the connectedness and interactivity of an in-person, face-to-face meeting, today’s audiovisual conferencing technology comes close.

Audio and video teleconferencing has long evolved since a decade ago when herky-jerky images, disconnected sound, and marginal performance were inherent in the technology and acceptable compromises for users. Even with the poor image quality, reduced frame rate, and audio latency, the ability to meet, conduct business, and communicate benefited users.

Times demanded change. High-speed data connections dropped in price, becoming accessible even to home offices. And, because the Internet enabled telecommuting, remote offices, and other modern distance-working arrangements, the need for reliable distance conferencing techniques grew.

In the book Audiovisual Best Practices, InfoComm (formerly International Communications Industries Association Inc.), notes that professional audiovisual system design and integration has become a vital part of the construction industry: In 2004 alone, the industry reported revenues of $19 billion in North America, with a projected growth rate of 9.6 percent over the next 5 years: AV conferencing is part of this revolution.

Technology Improvements
Despite earlier quality issues, the industry has pressed on to refine the technology surrounding AV conferencing’s two main elements: audio and video. With the older systems, one had to accept performance deficiencies and issues as part of the technology. That’s no longer the case.

“The technology has greatly changed in two ways - the quality of the basic video and the audio,” notes Randal A. Lemke, executive director of InfoComm International, Fairfax, VA. “The audio was the more difficult of the two. For doing good audio, it requires compression ratios and other technical things to get rid of a lot of feedback. It takes a quality person to install it in a room where acoustics are done well and a room where people can speak.”

According to a white paper, Emerging Technologies for Teleconferencing and Telepresence, from Wainhouse Research, Duxbury, MA, studies have shown that poor audio quality measurably increases the stress level of meeting participants. Video quality is another key requirement for an effective AV conferencing experience.

“It’s only recently, perhaps 2 years at the most, that I have been able to produce video teleconferencing systems for my clients and not have to give an explanation or make an excuse for limitations of the technology currently available,” explains Glenn Polly, director of VideoSonic Systems Inc., a New York systems integration firm.

With 25 years of experience, VideoSonic professionals have seen technology evolve. “Today, we can take an extremely powerful DSP Control Processor, choose the ideal microphone and speakers, locate the camera and lighting, and then tune and balance the audio system and the room and its components through software and calibration subroutines. The system is scalable from six seats to 60 seats; every seat is a good one,” Polly says.

Polly adds that approximately 60 percent of VideoSonic’s projects this year have been conference, training, and meeting facilities. All of these facilities required at least one teleconferencing system. Seventy-five percent of the facilities were prewired for future additions of this equipment.

Planning & Installation
Architects need to take built-in AV conferencing components under consideration early in the design process in order to make them work in any space. Too often, AV systems planning occurs too late, according to industry experts.

“The architect needs to understand early on what is needed for acoustics, sight lines, and what it takes to be a viable system,” Lemke says. “You also have to consider a design that people want to work in. It’s a marriage between technology and architecture.”

While many of the lower-end systems install with a D-I-Y mindset, Polly cautions architects and their clients not to lose sight of how important working with AV consultants and system integrators can be to the overall success of an installation. He says it’s more than product selection and installation. Training factors in, as does an inherent knowledge of all of an AV system’s quirks.

The success of an installation comes down to physics. You can install the highest-end system, but if you don’t account for the general physics behind how such systems work, the installation can be a dismal technical failure. “The room looks beautiful. It has mahogany casework. The furniture is Haworth and Herman Miller, and the food is great, but the communications are awful,” says Munira Fareed, vice president of marketing at LifeSize Communications Inc., an Austin, TX, developer of audiovisual conferencing equipment, of such a scenario.

The quality of audio and video in conferencing settings varies depending on the level of system installed and where it is installed and used. The low end of today’s audiovisual conferencing equipment includes self-contained solutions that run from a camera attached to a PC and running from the desktop to even elaborate speaker phones with sound-cancellation features. Quality on these systems is still better than full-service systems of the past.

Today’s systems are no longer installed on portable carts. Instead, they are built into boardrooms, conference rooms, and other permanent spaces. The codec is built into the system. The codec is the heart of an AV conferencing system. It codes the outgoing video and audio signals and decodes the incoming signals. Prior to transmission, it converts analog signals to digital signals, which it then compresses. Incoming audio and video must be decompressed and converted from digital back to analog on the other end.

Polly says his firm typically approaches designing a conferencing system from two points of view: client needs - such as how the system will be used, if data and application sharing will be required, and the source of data - and the room’s needs: Ceiling height, wall treatment, location of air handlers, and number of seats are considerations for choosing speakers and microphones.

“We locate a “back of house” position for the equipment rack which, in a typical system, can fit in a credenza or cabinet. We suggest the camera position to be 45 to 50 inches above the floor, approximately the same height as the top of a seated person’s head; this way you are looking straight ahead at the person you are talking to. This position gives the appearance that the conference table you are sitting at continues to the far side,” Polly says. “It’s a cool effect when done right, especially if you do matching rooms with the same furniture; you feel like you are in the same room.”

He notes that while front projection can be used, it’s not ideal as a display monitor. Rear screen projection is unaffected by room lighting conditions, so the brightness of the TV lights will not wash out the contrast in the picture. One-hundred-inch LCD and plasma flat panel monitors, when available, will be great as videoconferencing displays due to their size and widescreen aspect ratio.

Answers to Audio Challenges
A typical VideoSonic installation includes Biamp Audiaflex DSP control processors that when used with an installed AEC2W wide band echo cancellation card installed provide 20Khz of wideband echo cancellation, double the bandwidth of any other product on the market. A TE2 card, the telephone line interface card, enables the Audiaflex to connect and operate as a telephone device, Polly says.

Early speaker phones were “simplex;” you either had to push a button to talk or one party could talk, but the other couldn’t, Polly adds, noting that advances in echo cancellation technology have reshaped audiovisual conferencing.

“Now you have the ability for several people to talk without overriding each other, and you can have other people talk on the other side of the conversation with no degradation of sound quality,” Polly says.

Fareed stresses the need for high-quality audio in conferencing. “It is so important ... more important than video,” she says. “It’s important for people to be able to hear each other and understand the inflection of the person who is talking and to recognize who is talking.”

Microphone distance, speaker placement, room acoustics and reverberation, and lighting angles all play a role in the success of a conferencing system. Physics dictate that whenever you move a microphone away from the person speaking, you’re going to pick up more in the room; therefore, a single-point microphone isn’t going to do the trick in a large room. A microphone on the table picks up ruffling papers. Microphones on the ceiling pick up sounds from air ducts or the tethers get in the way of the video projection.

Polly says one of the best solutions for “miking” audiovisual conferences are wireless microphone pods. Shure Inc., Niles, IL, manufactures unobtrusive models that are 4 inches in diameter and have excellent sound quality, Polly notes. “It sits in front of you. The quality is good. It’s not going to damage the table. It’s not going to pick up the AC in the ceiling,” he says. “The only drawback is that the battery has to be changed periodically.”

Speaker placement also presents challenges. “You cannot have a microphone and a speaker in proximity to each other without them feedbacking,” Polly says. “The physics of sound is a very difficult thing.”

Polly likes to install Bose MA12 and FS8 speaker systems designed to reject feedback. These speakers, he says, are extremely focused as to where they direct sound.

“By using the proper speaker, you’ve already combated some of the physics working against you to begin with,” Polly says. “The physics are always there no matter what you do. Sound waves move through the air at certain speeds. The temperature of the air affects that. Speakers are an analog device. They move air and move sound to your ear. If you think four speakers are enough, you want to put in six to get even sound coverage.”

The type of room plays a role in sound quality, too. “The worst possible scenario for an AV conference is a glass fishbowl-type of conference room,” says Paul Depperschmidt, director of Atlanta-based Polycom’s AV Channels Group. “The sound reverberates off the walls with little to stop it.”

Lighting Influences Video Quality
While much attention is often centered on audio quality, video quality is just as important; how lighting influences that quality is crucial. It’s important to ensure the people at the conference table are properly lit so their faces will show up on the screen on the other end, Lemke notes, citing ceiling lighting devices from Lutron Electronics Inc., Coopersburg, PA, as one solution.

“The question is, ‘How do we make it look good without being obtrusive?’” Depperschmidt asks. “The technology can overcome some of it. You can crank up the input of the cameras we have now and essentially make the room seem to have more light.

“Even with the cheapest camcorder you buy, if proper lighting is used, it looks much better,” he notes. “It’s difficult to do in a conference room or a healthcare setting, though. But, you have to take into account that there has to be lighting in there.”

Improved video displays benefit from the lighting. High-definition displays, with an aspect ratio of 16:9, are becoming more readily available for videoconferencing use. HD video systems use high-power compression hardware and efficient encoding and decoding standards to increase “video realism,” providing as much as 10 times the resolution of standard videoconferencing images.

“It is if they are behind a glass,” Fareed says of the people on the other end of conferencing when an HD display is used. “And, because HD screens are longer you can get in both a person’s face and PowerPoint slides all on the same screen.” LifeSize’s flagship videoconferencing product, LifeSize Room, a fully integrated, high-definition video communications system, connects to any display in any size conference room. The system includes wireless remote control and a high-definition codec, camera, and audio conference phone.

Simplified User Interfaces
LifeSize Room offers a simple user interface - a common trend in modern and evolving conferencing equipment. “The phone has a video button on it,” Fareed explains. “You can use it to make a voice call or a video call. If you know how to use a conference phone, you can make a video call. People don’t need the IT department hanging outside the room to help with the conference. Technology doesn’t need to be in the way. It just needs to work. People’s experience with video has not been good. If anything is not fun, delightful, easy, or high quality, it won’t be used.”

Ease of use isn’t limited to LifeSize. There’s a “real push in the videoconferencing arena to make it easy,” Depperschmidt says. “You shouldn’t have to worry about calling IT to place a call. We want to make it something on demand. We’ve been striving for that in the conferencing industry for many years.”

The industry also is striving for faster, more enhanced communications. Traditionally, AV conferencing has relied on ISDN or a circuit-switched type of network built expressly for conferencing needs along phone lines. Conferencing now has shifted to IP-based networking, allowing connections to go through the Internet as long as the location’s bandwidth has the space to transmit the images and sound.

“IP gives you a higher quality image at a lesser cost,” Lemke says, adding that IP transmission is crucial in settings where quality of the image is important.

Depperschmidt says roughly 50 percent or more systems purchased today are IP-only. “The old circuit-switch ISDN world is not going to go away. We’re still going to have to address it,” he says. “We have to have a crossover between the ISDN and IP networks, a gateway to connect the two types. It’s something [that] should be considered early on in the project.”

Another ongoing evolution in video quality and IP connections are video codecs that provide quality videoconferencing without using heavy bandwidth. “That’s the holy grail of the moment,” Depperschmidt says. “Can we move things that look just as good but take up a lot less bandwidth?”

Internet connectivity will continue to influence and shape audiovisual conferencing beyond IP transmission, quality, and bandwidth issues.

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