3 Questions Schools Should Ask About WiFi

• By Bridget McCrea
• 03/10/11

As a wireless consulting engineer and chief blogger for WiFiJedi.com, Douglas Haider has watched the WiFi trend gain significant traction within the K-12 space, where 1:1 laptop initiatives and the use of wireless devices on campus are pushing districts to invest in state-of-the-art WiFi implementations.

"The biggest WiFi trends in K-12 education right now include the explosion in the number of devices--and, in the amount of high-bandwidth applications--being used at school," said Haider. "We've seen many schools go to 1:1 initiatives with a laptop for every student, or at the very least, install multiple laptop carts/mobile computer labs throughout the school."

Haider said student- and faculty-owned devices are also proliferating on K-12 campuses, where offering wireless service for WiFi-enabled phones, handhelds, and tablets--like Android tablets, iPads, and iPods--is becoming the norm.

These trends have shifted the typical district's focus from wireless coverage to wireless "capacity," said Haider. For example, he said capacity issues are magnified by the fact that schools are implementing higher-bandwidth applications--many of which include streaming video--within the classroom itself.

How Are You Going To Serve Capacity?
Knowing this, Haider said all school districts should figure out how much capacity they're going to use today, and how much they'll need six or 12 months down the road. This not only helps prevent shortages in the future, he said, but it also helps districts optimize their wireless networks' performance.

"When we used to wire up schools for Internet access, we always planned on having enough switch ports for current use, and for the future," said Haider. "It's no different with wireless, where each radio provides additional bandwidth for the end user."

In other words, if a single-radio access point can provide Internet service to 20 students, then a four-radio access point will hit 80 users. "You don't necessarily need a single radio for every user," Haider added, "but you do need enough to serve your capacity, and to handle any expected growth in user numbers."

How Are You Going To Serve Capacity?
School districts should also pay attention to the two unlicensed frequency bands where WiFi operates: 2.4 GHz and 5 GHz. "WiFi operates in an unlicensed spectrum, which means no complexities of owning licenses," said Haider. "The downside is that everyone can use it."

While 2.4 GHz is the more commonly used option (particularly for wireless devices, cordless phones, and Bluetooth devices), Haider said, the frequency "can get pretty crowded, and generate a lot of interference." On the other hand, 5 GHz's many non-overlapping channels provide seven to eight times the bandwidth in a given physical area, and without any interference issues. "This is definitely a key consideration for districts that are looking to deliver the best possible WiFi experience to users," said Haider.

Do You Offer Distributed Data Processing?
The final piece of the WiFi puzzle involves distributed data processing, or an environment where some of the functions are performed in different places and connected by transmission facilities. Haider said districts should focus on networks that are centrally managed, with the data being processed "as close to the edge" of those networks as possible.

"This allows data to take the most direct path to its destination," said Haider. "It's similar to what we saw as the Ethernet market matured. Initially everyone routed traffic at the core. Over time, as much intelligence as possible was pushed out to the network's edge switches, thus making traffic processing more efficient."

The fact that more students are using individual WiFi-enabled devices--and because more of those devices rely on high-bandwidth applications--makes distributed data processing that much more important for K-12 districts. "Districts don't want to push all of the data to a central controller because it will turn into a bottleneck," said Haider. "Instead, schools should be striving for centralized management combined with distributed data processing."

From a business perspective, Haider said school districts could conquer most of these challenges by seeking out vendors that have experience with similar K-12 institutions, and by asking a few important questions, like: How are you going to serve capacity? Do you operate in both frequency bands (2.4 and 5)? Do you offer distributed data processing? Can I talk to other districts that you've worked with?

"K-12 schools have been early adopters of WiFi, thanks to 1:1 implementations and increased use of wireless devices on campus," said Haider. "By asking the important technical questions early in the buying process, districts can avoid major headaches down the road."