University brings cellular indoors: coverage solution delivers wireless inside its facilities and will scale easily.
According to university operations manager Wally Hedman, the coverage problem cropped up as soon as construction began on the campus.
"We were putting in the underground utilities," says Hedman. "I'd be on the cell phone standing at ground level, and by the time I got a few feet down into a trench, I'd lose my connection."
Hedman knew from previous experience with wireless systems that coverage inside university buildings would be even worse, or nonexistent. The first buildings finished were the library, which housed the administrative and faculty offices, data center and library; an academic center; and three student dormitories. These were all constructed to withstand a hurricane, with walls that are almost two feet thick in some cases.
Since the campus enrollment was relatively small at the time, none of the major cellular carriers in the area was interested in paying for a solution at the site. As the library building neared completion, Hedman purchased a passive in-building cellular distributed antenna system (DAS) for deployment there.
The crews deployed an antenna on the building's roof and fed the signal to a bidirectional amplifier and the system's master unit, which were installed in the school data center. From this master unit, the signals were carried over runs of half-inch LNR coaxial cabling to remote antennas.
The results, however, were not nearly good enough. "We wanted mostly to provide coverage for the public areas in the library, but if you moved one wall away, into an office for example, the system made no difference," says Hedman. "At the end of a 100-foot cable run, the signal loss between the antenna and the master unit was so great that there was no noticeable improvement in cell reception, unless you were standing directly under the antenna."
With 1,000 acres of land on campus, the university plans to add new facilities over the next 20 years. In fact, the university has completed its fourth dormitory (a 44,500 square-foot facility) and has already broken ground on a 120,000-square-foot dormitory that is scheduled for completion in July. "We needed a system that could expand along with our campus," says Hedman.
WIRELESS A SAFETY ISSUE
"We considered it an essential safety issue," he adds. "We had established a university requirement that every dormitory needed to have cellular service, and we needed cellular service inside the library building for administrative and faculty communications. We wanted to be able to reach anyone on campus via cell phone in case of an emergency."
Hedman wanted an active system, in which the cellular signal was regenerated as it was distributed, and he eventually selected the InterReach Fusion system from ADC. The InterReach Fusion system delivers consistent signal strength to every remote antenna through a system of active hubs and remote antenna units (RAUs).
"The Fusion system operated just like a switch, where the signal was converted from RF to intermediate frequency (IF) and back to RF, with the signal regenerated each time," says Hedman. "That architecture gave us high signal output at every antenna no matter how far it was from the signal source. After that, it was only a matter of deploying the antennas in a logical manner."
To cover the three-story library, Hedman's team deployed an InterReach Fusion main hub in the data center, and then placed two RAUs on each of the first two floors, and one RAU in the center of the third floor.
"Even though the building floors are concrete," says Hedman, "we had plenty of signal penetration to cover the whole space."
The installed system supports 850-MHz and 1,900-MHz frequencies for Alltel, Sprint Nextel, T-Mobile and Verizon users.
Once the library was covered, Hedman set his sights on each of the 40,000 square-foot dormitories. One of the advantages to the Fusion system is that it can extend signals over singlemode or multimode fiber, and the university had laid singlemode fiber to all building sites when the other utilities were installed.
Since each main hub supports four expansion hubs, Hedman was able to cover all three of the dormitories by linking expansion hubs to the main hub via fiber. His team added an expansion hub in a wiring closet on the main floor of each dormitory, and then fed signals from each expansion hub to the RAUs using standard CATV cabling. "For the most recent dormitory, we just added a new main hub and expansion hub to the existing DAS and the whole system was expanded," he says.
Another advantage of the Fusion system's architecture is its centralized management and monitoring. Hedman monitors the entire system from the data center. He also monitors electricity levels.
"Florida is the lightning capital of the world," he says, "but I can monitor all my incoming voltages from the utility. We probably took 25 lightning hits that affected our buildings last year, but all the buildings are on emergency generators, and we have UPS backups on the critical equipment, including the main hubs and the expansion hubs."
With the management and monitoring system, Hedman was able to spot and remedy the only fault in the system since it was deployed. "The installers used push-on coax connectors on the expansion hubs, and they should have used crimp-on connectors," he says. "We had a couple of the connectors pull loose at one point, so then we went around and replaced them all with crimp-ons and we haven't had any other problems since then."
The cost to cover five buildings was about $50,000, he says. t Typical costs for deploying the InterReach Fusion system run 10 cents to 50 cents per square foot of coverage.
"Cellular coverage is one of those things that everyone takes for granted," Hedman says. "They don't necessarily cheer when they have it, but they sure complain when they don't. It's hard to put an ROI on enabling people to communicate and allowing students to call their parents, or allowing our emergency services people to broadcast text messages about tornado alerts or other events."
The university has new students register their cell phone numbers as part of the admissions process when they arrive on campus so they can be made part of the emergency communications system. With the emergency system-used primarily for weather warnings during hurricane season-the school can simulcast text messages to all user cell phones at the push of a button.
With a fully scalable and centrally managed cellular system that guarantees coverage, the university has made cellular DAS deployments an integral part of its expansion plans. The university plans to build a new performing arts pavilion and a law school building. These and other new structures will receive DAS systems during construction, and they will also be fed off of Fusion main hubs in the data center.
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|Title Annotation:||Wireless; Ave Maria University|
|Comment:||University brings cellular indoors: coverage solution delivers wireless inside its facilities and will scale easily.(Wireless)(Ave Maria University)|
|Date:||Mar 1, 2009|
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