New A/V Systems Use Cat 6 Cable

An eight-year, $260M expansion project that began in 2004 at the San Ramon Valley Unified School District involves renovating many of its 29 existing campuses and building eight new campuses. Besides a major investment in bricks and mortar, the district is implementing a complete upgrade of its visual learning systems on networks that use Category 6 cable.

The new system was installed in 400 classrooms in 2006 and 200 classrooms in 2007. Students, teachers, and the IT staff were impressed with the way it performed, which led to installing it in 150 additional high school and middle school classrooms this year (2008).

“San Ramon’s enrollment has grown from 18,000 students in 2000, to almost 25,000 today, and another 6,000 students are expected in the next few years,” said Jon Threshie, the district’s director of Technology. “Many are from diverse ethnic backgrounds with extended families, so there are more school age children per household than community developers anticipated.”

More Visual Learning

“Besides building new schools and upgrading existing facilities, we want to create more effective learning environments for our students,” Threshie continued. “Students, teachers, and technologies are all changing. Today’s students are more visually oriented than prior generations, younger teachers are more comfortable using new technologies, and presentation technologies are more sophisticated and affordable than ever before.”

In 2003, the district asked RTEJ Corporation to investigate and propose a state-of-the-art visual presentation system. Later, they hired the firm to write specifications, evaluate proposals, and test installed equipment.

RTEJ President Ric Johanson said, “The district decided to equip all new classrooms with Hitachi CP-X260 projectors, so all computer, Internet, video, and television programming would be projected onto a single high resolution display. The district also decided to standardize the cabling infrastructure so that all voice, data, and television signals would travel to the classroom on Category 6 cable. Voice and data are commonly delivered on Cat 6, but we discovered a new product from Lynx Broadband that delivers television as well.”

Connecting the Network

“Comcast delivers the History Channel, Discovery Channel, and other programming to each campus,” Johanson continued. “Our design brings the cable signal to a headend in one building, where it is routed to equipment and wiring closets in the other buildings on .625-in. hard-line cable. Then it is amplified and sent to Lynx hubs, which deliver it to the classrooms on Cat 6 cable” (see diagram).

Lynx hubs use broadband video baluns to convert unbalanced coaxial signals into balanced signals that travel on Cat 6. When they reach the classroom, they are converted back to coaxial signals that enter a combination DVD/VCR unit equipped with a television tuner. The output of the DVD/VCR is then delivered to the projector.

Outputs from a teacher’s computer, which include Internet pages, streaming video, and computer graphics, are also delivered to the projector through a shared audio/visual wallplate equipped with composite video, VGA, and RJ-45 data ports.

More Flexibility With Cat 6 Cable

“One big advantage of a Cat 6 network is that it is much more adaptable when teachers change the location of their desk, computer, and video system,” Johanson said. “A coax system is time consuming and expensive to change, because you have to pull new cable to each new location.”

“But with a Cat 6 network, we simply plug the DVD/VCR into a data outlet, move a patch cord in the wiring closet, and move the audio/visual wallplate to the new location, which is pre-wired with video and data cables running to the projector. The whole operation only takes about 30 minutes.”

“This provides several additional benefits,” said Threshie. “It standardizes our infrastructure, adds flexibility to our cable TV network, and reduces initial and ongoing costs. We now have Ethernet, voice over IP, television, and even an IP clock, speaker, and paging system all running on a universal Cat 6 network.”

More About the School District

Located in the Bay Area just east of Oakland, the district serves the cities of Alamo, Blackhawk, Danville, Diablo, the rapidly growing Dougherty Valley, San Ramon, and small portions of Pleasanton and Walnut Creek. Altogether, more than 130,000 people live in the district.

Making the district’s expansion project even more challenging is the sheer size of each campus, which usually has eight to 20 buildings, including one or more with 30 to 40 classrooms. High schools are quite large with 2,500 to 2,700 students, while elementary schools have 500 to 750 students. Other structures on campus are used for administrative offices, foodservice, a media center, library, one or more gymnasiums, and other facilities.

Gregg Kelley
is National Sales & Marketing Manager for Lynx Broadband, Burnsville, MN. He can be reached at