Saturday, 22 March 2008

Cisco's TelePresence system – High-Tec Teleconferencing

Use the term “video conferencing” and people start looking wary recalling only having experienced jerky, fractured images and out-of-sync audio. Even today, after more than 40 years when AT&T first introduced the Picturephone at the New York World’s Fair in 1964, few are impressed by the technology. For them, video conferencing you should try to skip.

However, that era may finally be coming to an end if Cisco Systems, Inc have anything to say about it. Cisco’s TelePresence high-definition video images are so un-television-like that during a demonstration a few curious corporate executives strolled behind the TelePresence display wall, to make sure the people in those images were not hiding back there.

The system is superior in four points, representing also the target-goals Cisco engineers had set for themselves from the very start of the project.
1. The images of the people appear life-size on the TelePresence screen in the exact proportions that they would in real life.
2. Employing high definition 1080p images, lighting is crucial to bring out human detail without making subjects uncomfortably hot. Users should see “the gleam or the tear in the eye,” as well as the sweat on the forehead.
3. The audio appears to emanate from the person who’s speaking as TelePresence screens are augmented by their own speakers. As a result, when a person who appears on the left screen speaks, the voice comes from that screen.
4. Although TelePresence signals traverse the Internet, users don’t have to type in IP addresses to make the calls. The system is as simple as dialling a phone handset.
“We want people to experience the meeting, not the technology,” Phil Graham, senior director of engineering for Cisco says. According to Cisco no training is required.

After this nice sales talk, let’s go a bit more technical
Cisco didn’t make cameras or video displays, two of the key links in the technical chain that comprises a video conferencing system; however it had gathered in depth expertise in Voice over Internet Protocol (VoIP), which would provide the knowledge to break down camera images, send them over a network and receive them on the other end.
But sending 1080p images (1,920 x 1,080 progressive scanning pixels) at 30 frames per second with low latency*), which the Cisco engineers had set as target, was an intimidating prospect. Without a 250-msec target, they reasoned, video conferencing sessions would be characterized by walkie-talkie-like communications, in which participants on both ends would be unable to speak simultaneously.
“With long latencies, you can’t interrupt,” Graham says. “You can’t interact. You can’t do all the things people do in a real meeting.”

Hardware and software engineers canvassed the technological landscape and learned that low latency 1080p HD was on the horizon: H.264, an emerging standard for video compression (also known as MPEG-4 Part 10), which enabled Cisco engineers to achieve higher video quality at a lower bit rate. That technology was augmented by the rapid emergence of 1080p large screen displays, enabling engineers to meet their goal of life-size images and new CMOS-based 1080p sensor technology. The new CMOS technology, an alternative to charge-coupled device (CCD) camera sensors, gave them the ability to more effectively collect and present 1080p images.

Moreover, the new sensors allowed Cisco engineers to present the 1080p data at 30 frames per second, a much higher frame rate than that of typical video conferencing systems, especially those on the desktop.

But still they were sitting with a monumental computing challenge in expecting the system to process all that imagery. In essence, signals from the 1080p sensor had to be transferred to video encoders, compressed, packed and transmitted over an IP network. On the receiver’s end, they had to be received, handed to a video decoder, decompressed and sent from processing hardware to the display, where it would be presented at 1080p.
The only answer was to build so-called “codec boxes” containing digital signal processor (DSP) arrays with on-board software algorithms. To handle the extraordinary amounts of data travelling back and forth, they endowed each codec box with 32 ADI Blackfin DSPs, each of which handles chunks of the large processing tasks, such as encoding. In all, a typical room-based TelePresence system uses three screens and more than a hundred DSPs.

But that was not all. To finish the product, they needed to design a room that would give participants the sense they were sharing a common area with other users, no matter how far away. They did that by using common colours and cutting meeting room tables in half so they appeared to continue into the screen and re-emerge on the other side.
To deal with lighting and colour issues, Cisco even called on famed movie cinematographer Janusz Kaminski, a Steven Spielberg cohort. Kaminski helped them change the colour palette from blue to a warmer brown and gave lighting tips in an effort to keep participants more comfortable.

And that resulted in an exceptional experience: “Most people are agape when they walk in,” says Jim Kittridge, senior vice president for Wachovia Corp. , the financial services company that has purchased several TelePresence systems. “They literally gasp; they can’t believe what they’re seeing.”

However amazing the TelePresence, Cisco isn’t alone in its creation of video conferencing systems. Hewlett Packard, Lifesize, Polycom, Teliris and others have jumped in with big, strong new products, thus reinvigorating the video conferencing space.

Industry analysts say broader success could depend, in part, on the creation of standard communication protocols that would enable Cisco’s TelePresence to talk to similar systems from such companies as Hewlett Packard and Polycom.

Cisco executives, however, are unflinchingly optimistic about the technology’s growth. Despite the product’s huge price tags ($299,000 for a TelePresence 3000 and $80,000 for a TelePresence 1000), engineers foresee it reaching homes within three years. Cisco CEO John Chambers already has one and the company expects TelePresence to find more at-home customers among big-company executives with a need to make calls around the world at all hours of the day.

*) latency = (computer science) the time it takes for a specific block of data on a data track to rotate around to the read/write head

This is an extract of an article from Design News, if you want to read the complete text click here


psycoticsinginchick said...

I still look forward to this technology being everywhere. I do hope it will be in my lifetime.

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