“Video Conferencing” and “Telepresence” are sometimes used interchangeably, but there is a significant difference in user experience that drives the technology. Theo Economides, lecturer, consultant and founder of Greenline Emeritus Consulting included a succinct description of the characteristics of "telepresence" in his presentation at the National Association of Broadcasters convention "Understanding the Basics: Telepresence Infrastructure & Architecture"
Where video conferencing transmits basic human voice and images, telepresence seeks to simulate “being there” by using advanced camera technology and placement to make people appear life-size, establish an illusion of everyone located in “one big room”, enable the participants to make “eye contact”. Sophisticated sound management helps participants hear voices “from” each person.
3 Basic Elements of Telepresence
Mr. Economides described three basic elements of a telepresence system: (1) The telepresence suite or end point(s), (2) the session border controller, and (3) the gatekeeper. End points can range from full immersion suites, to single user desktops, to new robotic video/audio communications tools (http://www.vgocom.com/). The Gatekeeper handles address translation and bandwidth management. The Session Border Controller (SBC) is a concept borrowed from the SIP world and maintains the full session state: security, connectivity, QoS, statistics and billing.
The various telepresence offerings from equipment suppliers have proven to be very effective communications tools. An interesting indicator of the success of the best implementations is a shift in technical conversations from “speeds and feeds” to describing aspects of “the experience”.
"Stick to 1 Video Vendor"
There is one important caveat, when looking for consistently excellent telepresence performance: at the moment it's best to stick with a single vendor. Interoperability is possible, but frequently it comes with a reduced set of features or capabilities. The Unified Communications industry has learned from earlier “protocol wars” that it is far better for all the players if they work together to grow the market than battle each other for a larger share of the existing market. To this end The International Multimedia Telecommunications Consortium is promoting the Telepresence Interoperability Protocol (TIP), a technology created by Cisco, to encourage telepresence solutions which “talk” to each other.
Looking a bit farther out, the IETF has established a Working Group with the somewhat tortured acronym CLUE, derived from the name of one of the most significant challenges to interoperability: Controlling Multiple Streams for Telepresence”. From the IETF description of the working group: “A major factor limiting the interoperability of telepresence systems is the lack of a standardized way to describe and negotiate the use of the multiple streams of audio and video comprising the media flows.”
The IETF goes on to explain
“The WG will create specifications for SIP-based conferencing systems to enable communication of information about media streams so that a sending system, receiving system, or intermediate system can make reasonable decisions about transmitting, selecting, and rendering media streams.”
Obviously the basics for successful telepresence deployments are available, but care and consideration must be applied to achieve the best results at the best cost. Understanding how to meet your business needs while minimizing interoperability issues and preparing to take advantage of emerging technologies.
