Wireless to the nth Degree

Wireless access points that utilize the 802.11n standard offer super fast speeds and can simultaneously support a multitude of bandwidth-hogging devices. For many schools, the benefits offered by enhanced technology in the classroom are balanced by an equivalent number of hurdles, from budget to buy-in to technical issues.

• By Michelle Fredette
• 09/12/11

When Washington's Bremerton School District considered running an iPod-based reading pilot in one of its elementary schools, the IT department was forced to confront the reality of its wireless network--and it wasn't pretty.

"We did have a wireless network, but it was kind of a means to an end--an early solution that we had had problems with," says Steve Bartlett, technology supervisor for the district. "For example, we couldn't connect more than 10 to 12 devices to an access point before we had problems with authentication, latency, and speed."

For many schools, the benefits offered by enhanced technology in the classroom are balanced by an equivalent number of hurdles, from budget to buy-in to technical issues. Bartlett and his IT department of five overcame the budget and backing hurdles when the district hired a new school superintendent with a strong focus on technology. "With the superintendent's expectations clearly communicated, it was very easy for us to move forward, rearrange budget priorities, and make it happen," Bartlett says.

As for concerns about technical issues such as support, coverage, and security, a new wireless technology--specifically 802.11n-capable wireless access point technology--had many of the solutions.

Faster Speeds, Increased Coverage
With a data rate of up to 600 megabits per second, 802.11n-standard access points (APs) achieve speeds up to six times that of their predecessors, 802.11a, b, or g, and they can support 50 to 100 client connections at once, even if those clients are using bandwidth-intensive applications that stream video or deliver voice over wireless LAN. They also incorporate MIMO (multiple-input, multiple-output) antenna systems that can bounce radio waves off walls and other obstacles, and reach the desired receiving device from different paths, or spatial streams. Among other things, MIMO enables faster transmission and wireless access in places that were hard to penetrate with earlier wireless technology.

The 802.11n technology also incorporates a new, third spatial stream, which Kevin Secino, global product marketing manager for mobility at HP, compared to opening a third lane on a highway. "You get more traffic through three lanes than two," he explains. "You can think of this in a similar fashion. We're able to transmit more data through three streams than two." The three-stream technology is also completely compatible with one and two spatial streams, as well as a, b, and g technology.

Band steering, a common feature of most access-point devices, helps to keep traffic flowing smoothly on all three spatial streams. Band steering is the process by which an AP detects when a client device is n capable and steers that device onto the 802.11n streams so legacy devices can use the 802.11a, b, and g streams.

Also included in many vendors' 802.11n AP technology is beamforming, which optimizes the link between clients and APs by reducing power usage and interference, enabling APs to operate at stronger signal strengths. "Beamforming helps you get higher throughput for further distances, because it's concentrating the energy toward your device, rather than sending the energy everywhere," explains Jeff Schwartz, HP's global product manager for mobility.

Beamforming enables the access points, which usually contain three transmitters, to time transmissions so packets arrive at their destination at exactly the same time. With previous technology, Schwartz says, the three radios would transmit, and traffic from one would arrive slightly before traffic from another because they took different paths.

There can be a downside, however. Beamforming relies on a signal exchange between the access point and the receiving device, which can be less effective if a device is moving around and the signal has to be repeatedly reset.

The Best Solution-- for Now
Most access points utilizing 802.11n standards have comparable speeds and performance. "When it came down to it, the technical aspects--can we get the coverage we need, can we get the right kind of security, can we segment the traffic--all these were present in all the solutions," says Bartlett regarding Bremerton School District's process of testing and selecting a wireless solution.

Bartlett adds that because he was open about his process and available budget, the four vendors he tested came up with comparable costs. "They came to within hundreds of dollars of each other," he says.

Ease of use was eventually the deciding factor for Bartlett and his team, which chose Meraki for the district's wireless technology. Contributing to that sense of ease is a cloud-based control solution that hosts functions customarily managed by a controller, a device that sits on the network and connects to the access points.

"It's all done through a secure web browser, so an IT administrator can deploy the network with the appropriate security and guest access policy and access control without having specialized training and wireless certifications," explains Kiren Sekar, director of marketing at Meraki. While it's common practice for wireless companies to offer a web interface, they generally still require a controller.

Bartlett says the department couldn't afford the time and cost of sending an employee to a five-day course to learn how to deploy and manage the network, nor could it "open up the manual and relearn the interface" every time a change to the wireless network was required. The new solution allows IT staff to access the wireless network to make changes and find answers to questions on the fly, even from meetings and conferences, using whatever devices are available.

The Meraki access point/cloud-based control solution incorporates a couple of security features that are especially useful in a school setting. One of these is network access control, a feature that checks devices for working antivirus software before they are allowed to connect to the network. Another feature is traffic shaping, which "can limit how devices are used, when they are used, and what types of applications can be used over them," Sekar says.

That means access points can be set to allow specific educational applications but prohibit students from accessing web sites like Netflix, game sites, or YouTube. Bartlett says that this feature is especially useful in high-traffic areas near meeting rooms and classrooms where students are not able to stream video, suck up the bandwidth, or interfere with instruction.

Bartlett says teachers who are excited by the new technology continually find new ways to use it. He makes note of an iPod reading program that would never have taken place without a better wireless infrastructure. The program's results have been phenomenal, according to Bartlett. In a matter of weeks, students moved from being low-level readers to reading above benchmarks, and classes are now seeing fewer discipline problems.