As it rolls out its third-generation wireless infrastructure, the Saratoga Union School District is exploiting all that the latest technology offers: centralized management, load balancing across wireless channels, and even optimized network topology and design.
Howard Lorenz, director of technology for the district's three elementary schools and one middle school in Saratoga, Calif., has learned a lot about wireless over the years. When the district began deploying wireless hardware a decade ago, "We populated as many areas as we could with whatever wireless we could get our hands on, not realizing we were committing a big design error," he says. "I don't think a lot of us knew about channel interference, proper placement of access points and load balancing."
What a difference a few generations of technology advances make. Today, Lorenz can monitor how many of Saratoga Union's 2,200 students and 250 teachers and staff members are using the wireless network at any given moment – even from his living room.
Like many other districts around the country, Saratoga Union is working to give teachers and students wireless access to network resources and the Internet from any computing device. All district officials may soon find they have no choice: As increasingly popular mobile devices move toward ubiquity, stakeholders will come to expect it.
According to Thomas Greaves, chairman of the educational technology consultancy The Greaves Group, half of the computers used in schools today are mobile devices. Students and teachers are using them primarily for web surfing; to access curriculum systems and content; and to check assignments and calendars. "As you go mobile, you need to have connectivity," Greaves says. "Wi-Fi is the way to do that."
Voice of Experience
When Lorenz added 802.11n wireless controllers and more than 60 access points to Saratoga Union's ad hoc wireless infrastructure about five years ago, he configured the APs using the same service set identifier and the same login credentials. Every AP operated on the same radio frequency out of the box and had to be configured individually. "We had APs acting as individual soldiers running full blast and interfering with each other," Lorenz says.
By mid-2010, Lorenz knew he needed a more coordinated approach. He chose Aruba Networks equipment for its management capabilities. Aruba's mobility controllers operate on a master/slave model, through which the slaves acquire configuration information from the master system. The APs are rebooted independently; other commands are executed from controllers. Saratoga Union uses one controller per site to manage the APs.
Built-in network planning capabilities are a key component of Aruba's products. "Aruba uses an algorithm to suggest where you should place access points based on the number of users, the architecture of a building and, to some extent, even the construction of the building," he explains.
Aruba recommends that individual users be associated with certain APs so that the system can load-balance across available APs based on location and usage. The system can be configured for redundant connectivity if applications dictate that level of reliability. "You can build the system [to be] as robust as you really need," Lorenz says.
The products' planning functionality helps avert bottlenecks that can occur when high volumes of users concentrate in certain locations, and to ensure that the network adapts as it's built out. "We're 70 percent done with our initial rollout," Lorenz says, "and when that's complete, we'll look at our heat maps to see how coverage is working." From there, "we'll fill the void with more access points."
The Move Toward Centralized Management
In summer 2009, Nevada's Douglas County School District began deploying nearly 80 Ruckus Wireless APs at its 12 schools and two offices in and around Minden. Centralized control and robust bandwidth management were key factors in the district's product selection as well.
The Ruckus product line's ability to detect heavy usage from a high number of users and to dynamically allocate signal strength so they don't see performance degradation was particularly appealing, says Eric Ristine, director of information services for DCSD. The technology "allows a single access point to alter the broadcast characteristics of a signal to a wireless device," he explains. "If there are 15 people in a room, the AP can direct the most broadcast power to that area dynamically, on the fly, without any interaction."
Ristine also liked the fact that his district needed fewer access points to achieve the same coverage. With Ruckus, he says, "we [used] half to two-thirds fewer APs than we would have needed from other brands. Less wireless hardware infrastructure to manage, secure and install resulted in six-figure cost savings."
The Council Rock School District in Bucks County, Pa., also has adopted a centralized wireless management approach. The 15-school system began integrating wireless technology into its overall network architecture last year. Wireless controllers are blades housed in the district's Cisco Catalyst 6513 switches, thereby providing robust management functionality from a central point.
Those controllers support nearly 300 Cisco Aironet APs today, and the district expects to increase that number to nearly 400 over time, says Matthew Frederickson, Council Rock's director of information technology. Wireless also is integrated with the district's Active Directory domain, which controls authentication.
"When we're completely done with all our buildings, we'll have 300-megabits-per-second access anywhere," Frederickson says. "We're moving to the point where all of our classrooms will be saturated" with wireless access – just one component of an overall building renovation plan.
Schools increasingly are moving to make wireless ubiquitous on their campuses. The trend raises questions, however, about existing access policies and how they need to be modified to reflect new realities in computing.
Among other things, district officials must determine who can use the infrastructure; what devices these authorized users are permitted to have; and which applications and data, if any, will be restricted. Examples from several districts with significant wireless experience are instructive.
At one end of the spectrum is California's Saratoga Union School District, which allows essentially free access to information and encourages extensive use of wireless. "The whole philosophy of our district, especially with students, is to teach proper behavior rather than using an incredible amount of control to force behavior on students," says Howard Lorenz, director of technology. "Rather than filtering the whole world, we talk about appropriate use, and open wireless fits right in with that."
By comparison, within Pennsylvania's Council Rock School District, only district-owned equipment can access the existing wireless infrastructure. "We have an acceptable-use policy and an electronic-device policy," says Matthew Frederickson, director of information technology. "If students bring in their own laptops to take notes, [they must sign] an agreement stating that they won't try to use those devices to access the network."
The most important thing to remember with acceptable-use policies is that they are fluid documents and, therefore, subject to change as needs dictate. Frederickson says his district plans to offer more open-access policies in the future, as it builds out its infrastructure more extensively.
Amount the Saratoga Union School District has spent to date on its current wireless initiative