Connections +
Feature

The Wireless Classroom

Calgary board of education has embarked on an ambitious project in an attempt to provide both students and teachers with instant network access.


November 1, 2002  


Print this page

A computer isn’t much without network access these days, and that’s as true in the classroom as anywhere else. But how do you hook up a classroom-full of PCs to a network without stringing a spider’s web of wires across the floor, and how do you get the most out of the limited number of machines a school’s resources can buy when those computers are tethered to a network?

The Calgary Board of Education – one of the country’s largest boards with more than 220 schools and about 90,000 students — has decided the answer is wireless networking. Starting this year the board is adding wireless technology to its existing school networks, allowing instant network access from anywhere in the schools.

This means more computers can be used in a single classroom at one time, says Mike Bester, information and communications technology curriculum specialist with the school board. The need to hook up to wired network connections run through or along walls meant that “you could pretty much only fit four computers in a classroom,” Bester says. In some cases computers had to sit under blackboards because no other wall space was available. With wireless, laptop computers can easily be moved around the classroom, and more can be accommodated in a single room at one time.

At Tom Baines School, which has about 750 students in grades seven through nine, the board has 70 laptop computers and will be buying more.

Five wireless access points, each with a range of about 100 feet, provide coverage throughout the school, according to Richard Tapp, project leader for the wireless pilot project at Tom Baines.

Tom Baines also still has some computers using wired connections, for instance in computer labs. “We don’t say that we should replace the fixed-wire desktops,” Bester says, “because there’s a place for some of those, especially when you come to high-bandwidth, multimedia type of work.”

The Avaya Inc. wireless networking technology Calgary is now installing conforms to the 11-megabit-per-second 802.11b wireless Ethernet standard. Avaya is planning to introduce 54-megabit-per-second technology, and John Williams, director of distribution and sales at Avaya Canada Corp. in Markham, Ont., notes that upgrading the existing wireless access points will simply involve swapping a single module. Bester says this was one of the features that attracted the school board to Avaya’s products. In the meantime, the Calgary Board finds 100-megabit wired Ethernet better for some purposes.

Tom Baines School was the test bed for Calgary’s wireless installation plans. Ten more schools, ranging in size from about 350 to more than 1,000 students, inaugurated their wireless networks at the beginning of September. The board’s plan is to extend wireless networking eventually to all of its 220-plus schools. There is no firm timetable for this, and recent budget cuts may slow the process down a bit, Bester admits. However, he also expects the process of rolling out the wireless technology to get easier as technical staff and contractors gain more experience. The board has deliberately picked an assortment of schools of different sizes, different types of buildings and different grade levels for the initial installations in order to learn as much as possible in the early stages of the rollout, Bester says.

The pilot project brought some pleasant surprises. “It seemed to set up easier, than expected, was more stable than expected and the coverage was better than expected,” Tapp recalls. One reason for the better coverage was probably the design of Tom Baines School. Opened in 1997, the school has a “passive supervision” design with many large internal windows between classrooms, corridors and other spaces.

Those windows proved transparent to wireless signals, Tapp says, and it probably also helped that the interior walls of the school are built of steel studs and drywall, rather than concrete block or other denser materials as some schools are. “That type of construction seems to be more transparent to this type of technology,” says Tapp.

The result was that instead of needing three wireless hubs for each of the school’s four pods, it was possible to do the job with one hub per pod plus one for the Centre Court area housing the library, music and common areas.

Not all the surprises were good ones, though. In its lunchroom, the school has two industrial-type microwave ovens.

When the network was first installed, it was set to operate at a frequency too close to that emitted by the microwaves, and “when they were turned on they knocked the network down,” Tapp says. The problem was fairly easy to fix, though: The Avaya hubs offer a choice of several operating frequencies, and once technicians found out at what frequency the micro- wave ovens operated, switching the network equipment to a frequency farther from that of the microwaves solved the problem.

With about 220 wired workstations already in place, the wireless hubs might have been attached to wired ports. The Calgary Board of Education’s wiring policy, however, dictated that new network and power cabling encased in conduit should be run to each hub, with the hubs linked directly back to network switches and electrical panels. Hubs are mounted on ceilings for best coverage.

Tapp adds that each of the wireless hubs is tied to a particular network port, making it easier to manage the hubs remotely from a central school-board facility rather than locally at the school.

To ensure security, the network cards of all computers that are allowed to connect to the network are assigned addresses, which are checked against a central database.

Only recognized systems can log in to the network. The network also uses 128-bit encryption, Tapp says. The laptop computers are signed out in groups of 10 to teachers, who can then sign them out to students.

Tapp says Tom Baines School has had laptops since 1997 and in that time has lost only one – in that case, he says, the usual security procedures weren’t followed.

After the successful wireless pilot at Tom Baines there was some delay while the board dealt with a variety of issues. Among them were concerns about security and about health and safety – the board had to satisfy itself that the laptop computers would not emit radiation that could be harmful to students, Tapp says. With those questions answered, the final installation went ahead in May of this year.

Wireless access is already making a difference in classrooms, Tapp says. For instance, four encyclopedias that were previously available to students on CD-ROM are now accessible via the Internet, put there for student use by the provincial government. Students also have access to other online resources, and each student has a private folder on the network server to store files which he or she can get at from anywhere on the network.

Some other schools may not be quite as easy as Tom Baines. Not all of Calgary’s schools have the kind of open design that it uses, so more access points may be needed to achieve full coverage. In some cases it may be an option to use portable access points that can be plugged into the existing hard-wired network jacks.

One school will present a unique challenge. There was a fire in the building about 15 years ago, Bester explains, and afterward it was impossible to remove the smoke smell from the walls, so they were painted with aluminum paint to seal the smell in. The aluminum paint interferes with wireless transmission, meaning signals essentially cannot penetrate the walls.

The board has done some tests in the school using mobile access points, Bester says, but another possibility is to spend extra money and install a permanent access point in every classroom.

The board may use mobile access points in other schools too, depending on the cost of installing the necessary wiring to provide complete coverage with fixed hubs. Mobile access points could plug into existing network ports, significantly reducing costs. On the other hand, Bester says, the board prefers fixed hubs for security reasons.

The other wiring issue is electrical power. For installa
tions to date the board has chosen to run electrical cable to the access points where power was not already available. The other option, Bester notes, is an emerging power over Ethernet standard that was developed partly in response to the need for a way to power access points located in awkward places.

Bester does not expect that wireless networking will ever take over completely in Calgary’s schools, but he likes the possibilities that open up when computers are no longer physically tethered to a network — possibilities like entering the results of science experiments wherever they are performed. “It’s not an either/or kind of thing,” he says. “Wireless is being used to extend the functionality of our wired network. The greatest thing about wireless is it allows us to take connectivity to the teachers and the students where they’re actually teaching and learning.”

Grant Buckler has written about information technology and telecommunications since 1980. He is now a freelance writer and editor living in Kingston, Ont.


Print this page

Related