While no-frills desktop videoconferencing tools such as Apple's iChat AV and Microsoft Windows NetMeeting are rightfully enjoying their day in the sun, traditional room-based videoconferencing technologies continue to be mainstays in schools across the country. Unlike Web conferencing, which only requires a computer with a high-speed Internet connection, a Webcam, and basic software, room-based videoconferencing is much more involved-requiring cameras, video encoders, microphones, and a special network infrastructure.
The power of room-based videoconferencing is its ability to handle real-time, synchronous interaction by multiple users at different geographic sites. A group of students may, for example, take advanced mathematics classes offered by instructors in remote school districts or community colleges, thanks to installed and supported videoconferencing systems. Or they might participate in large-scale virtual field trips hosted by NASA, national museums, local zoos, and many other organizations.
VTEL's IP-based Vista Large
Classroom System includes 16 push-to-talk microphones.
In the past, room-based videoconferencing calls relied on specially leased phone lines. These connections generally used ISDN lines and incurred costs based on the respective locations of the end sites, the cost of establishing phone connections between each site, and the number of "channels" used during the call.
These days, however, you're more likely to see IP-based or H.323 classroom videoconferencing, which means video, voice, and data are routed as "packets" over the Internet. Because IP-based connections use existing Internet infrastructure and bandwidth, they are much less expensive than ISDN connections.
The lower cost of today's room-based solutions, not to mention their smaller size and portability, means districts are relying less on third-party companies to provide distance-learning room integration and design services; they are going directly to the vendor. Below, we've outlined some key issues to consider when selecting one.
Given the wide variety of videoconferencing solutions on the market today, how should district staff select a vendor and specific products?
The answer depends both on existing systems in the district and current and future videoconferencing needs.
Consistent User Interface
If the school district already has a large number of installed videoconference units, a case can be made that end users will benefit from a consistent user interface, and IT support staff will welcome the hardware standardization. Put simply, if the district has already invested in TANDBERG systems and is happy with them, it makes sense to stick with the vendor for future hardware purchases.
Some solutions provide proprietary functionality that may or may not be needed by the district. If remote camera control is required, for example, make sure to purchase hardware from a vendor providing this functionality. Note: although open standards for camera control do exist, many videoconference hardware protocols will only remotely control other protocols from the same manufacturer.
Distance-learning classrooms used to be "fixed" by necessity, but today, portable units are available that can be moved as needed into different classrooms or conference areas. If portability is a current or predicted future need, consider a portable system instead of a fixed-room installation.
Districts should purchase systems from vendors with not only a proven track record and broad customer base, but staying power in the market. At one time, VTEL had a large market share in the K-12 videoconferencing arena. Today, VTEL remains a player in the global educational videoconferencing market but has lost ground to Polycom and TANDBERG.
Polycom's ClassStation Large system
features H.264 video and automatic camera operation.
According to the Wainhouse Research Bulletin, in the third quarter of 2004, the overall videoconferencing market share leaders were Polycom (44 percent), TANDBERG (23 percent), China-based companies (14 percent), Sony (8 percent), and Aethra (7 percent). VTEL had a 1 percent market share.
Often a distance-learning room integrator-contracted by a district-will write a customized computer program for the control panels (e.g., AMX, Cresstron) used in concert with your videoconferencing equipment. Before purchasing a solution that includes programming code, obtain a signed agreement from the vendor that the source code and the intellectual property rights for the code will be released to the purchasing educational entity (your contractor). This insures that if changes are needed, the district will not be limited to doing business with the original vendor. Additionally, this protects the district in the event the contractor goes out of business or the programmer who wrote the code leaves the district.
One of the most exciting new developments in the area of videoconferencing concerns the MPEG-4 Codec, specifically called H.264 video compression and videoconferencing. Some video compression technologies, like those used by Windows Media Player, are proprietary; they are owned and licensed by a single company (in this case, Microsoft). In contrast to these proprietary standards, open standards are publicly available and can be used by commercial and nonprofit entities. H.264 video compression is already incorporated in some distance learning videoconferencing solutions, such as the Polycom VSX 7000.
The new Educator MXP from TANDBERG
incorporates the H.264 video standard.
What makes H.264 videoconferencing compelling is its high quality, relatively small file size, and scalability. Scalability refers to the potential for an H.264 video stream to be "scaled down" to play well on a handheld phone or "scaled up" to play on a high-definition video system.
For today, however, bandwidth limitations and budgetary and time constraints of school districts generally prevail. Despite these challenges, the opportunities for educational videoconferencing have never been more promising.
Wesley Fryer is director of instructional support services and former director of distance learning for the College of Education at Texas Tech University.
Let's Get Technical
Various videoconferencing protocols explained.
Codec: protocol used to reduce the size and quality of encoded video and audio packets traversing a network connection path between two or more sites
H.263 codec: protocol used in Apple's iChat application
H.264: "next generation" video compression technology used for applications ranging from cell phone screens to high definition video and audio
H.320: also known as ISDN, the industry standard for paid, connect-over-phone-lines videoconferencing
H.323: IP (Internet Protocol)-based videoconferencing widely used in classrooms today
Making the Connection
How does interactive videoconferencing actually work?
Videoconference connections can be divided into two groups: direct, point-to-point connections and bridged calls.
Direct: Depending on how each local network is configured, a teacher with access to a videoconference unit may be able to directly connect to a videoconference unit at another site. This is generally referred to as a "point-to-point" connection. Many factors can hamper educational users from making direct point-to-point videoconference connections, however. The local network may be configured to block IP traffic using standard videoconferencing ports, and/or the network may be configured to require videoconferencing equipment to connect through a district "gatekeeper." Since videoconference connections can use significant bandwidth, network administrators typically limit individual users from making unauthorized videoconference connections from within the school network.
Bridged: "Bridged" calls use a Multipoint Control Unit. An MCU allows multiple participants to join in a videoconference and generally provides greater connectivity and bandwidth management options. MCUs are extremely expensive pieces of network hardware and generally are owned and operated by universities and local education service centers. If a school district is a member of a regional videoconferencing network, along with a local college or university, the university will often provide free bridging services for local districts. Even better: if the district is able to get sponsored by a member of the Internet2 consortium, it can take advantage of high-speed, optimum connections physically separated from the "commodity" Internet.
Whether your calls are point-to-point or bridged, "quality of service" is key to making a good connection. The basic idea behind QOS is that "packets" of information traversing a given network should have varying levels of priority. Without QOS, the packets coming into the school network requested by a teacher streaming an Internet radio station would be given the same "rights" to access available school bandwidth to the Internet as students taking a Calculus II course in the school distance-learning room.
Alhough QOS does not guarantee improved quality of service, an increasing number of districts are using it to better manage network bandwidth utilization and boost user confidence in the quality of available videoconference connections.
Desktop Videoconferencing: A Closer Look
The pros and cons of a promising technology.
The near ubiquity of high-speed Internet in schools, coupled with the increasing numbers of students with home broadband connections, has made inexpensive, easy-to-use desktop videoconferencing software solutions more viable than ever (see "New and Net-Worthy Presentation Applications")
With ease of use and low cost come some downsides, however. For one, although some desktop videoconferencing software is based on protocols that are openly available, not all solutions are interoperable. In other words, someone using Windows NetMeeting cannot videoconference an Apple iChat user.
In addition, desktop videoconferencing solutions may not work seamlessly due to network security measures and limits imposed on users' Internet connections. This doesn't necessarily mean that desktop videoconferencing software like Yahoo IM or iChat will not work, but they may require school users to work with local or remote IT staff to open up ports in the local network or assign a global IP address to the computer used for videoconferencing.
The following vendors offer videoconferencing equipment, services, and more.