Reading, Writing, and WLAN Phones

By Gerry Blackwell

July 08, 2002

Forget that antiquated public address system. Getting ordered to the principal's office takes on a whole new meaning when the call comes in on the school's Wi-Fi phone.

Last year, a security guard at a school in New Brunswick, NJ, witnessed a grisly accident. A passerby tripped on a sidewalk outside the school playground and broke his nose. Blood gushed alarmingly. The security guard got on his walky-talky and tried to contact the school office to have somebody call an ambulance, but couldn't get through for several minutes.

"From the school district's point of view it fortunately was not a student that was involved," says Brian Auker, district technology specialist for New Brunswick Public Schools. "If it had been a student, there could have been major liability issues."

Now, in similar circumstances, New Brunswick school security guards can call the school nurse or an ambulance directly right from the playground using a portable Wi-Fi telephones from SpectraLink that the school district distributed earlier this year.

The phones, which work over the 802.11b networks installed at each school, are the most innovative part of a major $3-million communications overhaul the New Brunswick Public Schools began in February.

The project involved:

  • switching from conventional analog to IP telephone systems in each of the district's 13 schools
  • establishing 103Mbps fixed-wireless wide area links between the schools using 5.8GHz U-NII-band technology
  • installing 802.11b wireless LANs in each school to provide high-speed Internet access in each classroom
  • installing the WLAN telephone systems.

The wireless LANs, based on standard Cisco 802.11b equipment, made sense because at least five of the aging school buildings in the district are due to be replaced in the next few years. Under the circumstances, it did not make sense to invest heavily in wired infrastructure, Auker says. When the time comes, the wireless LAN gear can be taken out of the old schools and reinstalled in the new.

It took an average of 20 access points at each school to provide complete indoor and outdoor coverage. While the primary reason for wanting the school-wide Ethernet networks was to provide high-speed Internet and intranet access in each classroom, the wireless phones were always part of the equation.

To add the wireless phone capability, the school district had to install $3,000 worth of SpectraLink gateway devices in each school. They allow the phones to work with the Cisco Call Manager IP phone systems the district had earlier installed. The SpectraLink wireless phones cost about $500 each.

Since the wireless LAN infrastructure was planned from the beginning to support the phones and was installed only shortly before them, there was no question in this case of having to upgrade WLANs to accommodate the extra capacity requirements of telephony, Auker says. In any case, he notes, the phones use digital voice compression and only require about 8Kbps of bandwidth per call.

The school district distributed 120 SpectraLink Wi-Fi phones in the first phase of the project in March of this year to custodial, maintenance, security and IT support staff, as wel as all principals and vice principals. It will add another 700 by September to equip each classroom teacher.

Thanks to the U-NII-band links between schools, the phones work anywhere in the district. As with a cellular phone, as soon as a user walks into a school's WLAN coverage area, his phone is immediately on the network and he can be reached at his wireless number.

The wireless phones provide a variety of benefits, Auker says. Custodial staff, for example, move around the school all day so they're often difficult to find and communicate with when needed. Now they're easy to reach.

If there's a problem with a school's boiler or some other piece of equipment, rather than coming to the office, the custodian can use his wireless phone to contact the manufacturer while he's right in the boiler room and can describe symptoms accurately. "It makes them more efficient," Auker says.

IT and maintenance staff don't just move around the schools, they move around the district. Wherever they go now, their supervisors can find them. In fact, Auker, as network administrator, can do a search on the MAC address of any staff member's phone if he wants and find out if the person is where he's supposed to be. "That's one thing they don't like," he admits.

The benefits for security guards are obvious. It allows them to be proactive in the event of an emergency. Liability issues are not uppermost, Auker says, but they are a factor.

"You have to constantly keep in mind the welfare of the children," he says. "You do whatever you can do to make the environment safer. There's only so much you can do, of course. You can't always prevent falls or fights. But at least with this technology we can react quicker if somebody does need help."

Equipping classroom teachers with phones was one of the major objectives of the communication overhaul. The primary motive was to make them more accessible to parents. "You have to have parent involvement in education anymore," Auker notes.

In the past, if a parent called, they would have to leave a voice message for the teacher. The teacher would use the phone in the staff room to collect messages and return calls, and that phone was usually in high demand during break times. It made communication difficult.

Now teachers won't have to contend for the one or two phones in the school available to them. They'll be able to collect messages and place calls right from their classrooms, saving time and effort. Better classroom security is an added benefit, Auker says. Teachers can use the phones to call for help in an emergency.

When a school district representative asked Auker why he didn't just install wired phones in each classroom -- either phone company lines or Ethernet drops for wired IP phones, Auker did some analysis.

Putting in phone company lines wasn't really a serious option. It would incur hefty installation and ongoing monthly charges, something New Brunswick -- like many other school districts -- was trying to avoid. Eliminating ongoing phone company charges was also the reason he installed the U-NII-band wide area links.

Installing wired IP phones, with cabling costs and additional network infrastructure required, would come to about $900 per room, Auker calculated. Furthermore, the investment in cable would be lost when the old schools were decommissioned. The SpectraLink wireless phones cost about $600 per room, and all of the infrastructure can be re-used.

Once the teachers have their Wi-Fi phones, the project will be complete, Auker says. The only refinement he can see is the addition at some point in the future of dual-mode Wi-Fi/cellular phones for maintenance and IT staff so they can communicate while moving between schools. The first dual-mode products should be appearing on the market later this year. SpectraLink also has a NetLink line of Wi-Fi phone systems that can be integrated with legacy phone systems.

Could New Brunswick's use of Wi-Fi telephony serve as a model for other school districts? Auker cautions that the network he installed made economic sense partly because he had already switched to wired IP phone systems. There are well-documented benefits to going the IP route for phone systems, of course, so it might make sense for other districts as well.

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