William & Mary Is So Very Unwired … and Proud of It

Students and faculty alike prefer the convenience of wireless network access over wired connections. Photo courtesy of the College of William & Mary.Students and faculty at the College of William & Mary already enjoyed one of the best university wireless Internet systems in the country. As far back as 2005, Intel named it one of the top-50 WiFi-connected universities in the U.S. When students showed up to start classes this past August, though, they found the system was getting even better.

“Currently we probably have 1,200 access points,” says University Network Manager Scott Fenstermacher, referring to the wireless transmitters connected throughout the campus to the university’s hard-wired Ethernet system. “With the upgrade, we’re likely to put in even more.”

One reason for so many access points is that speed and connectivity for wireless users—in classes, libraries, some outdoor spaces, and even dorm rooms—depend on a person’s proximity to one or more of these wireless access points located throughout the campus. The key factor the William & Mary network team considers, though, is not so much a student’s distance from any given access point as the density of students around these transmitters. Because a lot of people are competing for access to the wireless system, a heavily trafficked area will need more access points than areas with fewer users.

Everybody wants wireless

When the school first accommodated wireless Internet access seven years ago, the campus had only 15 access points, Fenstermacher recalls. As the system grew, the network managers learned a few things quickly. One is that everybody—students and faculty alike—tends to prefer wireless connection over plugging in to hard-wired desk-side or wall connections. Second is that system users also want their wireless network to be as robust as their wired network, with the capacity to connect phones, notepads, portable computers, game stations, or whatever other devices users want to connect.

Students might register media access control (MAC) addresses for as many as 10 different devices on the university wireless system, Fenstermacher says, noting that it is through those MAC addresses that the school’s virtual local area network (VL AN) recognizes legitimate wireless Internet users. (William & Mary also allows visitors to obtain VLAN access through a temporary system registration, which is somewhat unusual among other universities’ Ethernet- access  policies. This one-day access accommodates guest lecturers, vendors, and other people with a legitimate need for on-campus wireless access.)

The William & Mary wireless system is  focused  mostly  on  interior spaces. However, just as with the home-based access points, there is some bleed-over from inside transmitters to nearby exterior areas. This means that people can access the Internet in places such as the Sunken Garden outside Christopher Wren Hall without the university having to place access points outside where the transmitters would be visible.

The Wren Building

The Wren Building is an integral part of Wiliam & Mary tradition, as seen from the Sunken Garden. Photo courtesy of the College of William & Mary.

William & Mary maintains a Colonial America visual context, Fenstermacher explains. “We’re the second-oldest university in the nation. So we can’t pop an antenna in anywhere we want wireless service.” This is especially true of the Wren building. Although it has burned and been rebuilt three times since it was first completed in 1700, it is still recognized as the oldest academic building in continuous use in the U.S. “We don’t want people coming in with shovels outside that building to bury wires,” Fenstermacher says.

As with many of the buildings on campus, the Wren Building was last remodeled in the 1930s, following the financial support from John D. Rockefeller Jr. to restore Colonial Williamsburg. Unexpectedly, that created problems for the people installing access points. “In the 1930s, a common interior wall treatment was plaster over expanded-metal lathe,” Fenstermacher says. “We found that the embedded metal mesh acted essentially as a radio-frequency shield. It seemed that we couldn’t put enough access points in those buildings. Yet in very similar buildings that had been renovated with dry wall, we could get excellent coverage with a third the number of access points.

“Working within all these parameters of visual integrity and existing building conditions became something of an art,” he continues. “We walk around with a tablet PC to do RF studies to compile a heat map of coverage, and we have found that we need to be detailed in this analysis. Sometimes you will get a five-bar signal on one side of a dorm room doorway, for instance. But if you walk inside to the far wall of that room, even though it’s only a few strides away, you might go down to zero.”

Students take these modest limitations in stride. “Wireless Internet access is generally good across campus in classrooms and the library,” says William & Mary junior Adam Drici. “There’s even some decent coverage ou tside in some places . My main frustration with the WiFi at school is in the dorms. Wireless coverage in the majority of dorms is spotty. Last year in my dorm, there was only one transmitter for the entire building. Lots of students will actually just bypass the wireless completely and plug directly into the wall Ethernet port in the room because it’s much more reliable than WiFi in the dorms. That’s what I would always do.”

Handling the load affordably

William & Mary opted for a standard IEEE 802.11-compliant WiFi sytem transmitting over a, b, g, and now n frequencies. These systems are available from a number of enterprise companies. The university uses a  Cisco system, Fenstermacher says . In putting  the controllers, wires, and access points in place and maintaining them, his team has identified a range of lessons learned.

Because wireless is so popular, the user load can get very heavy. So, in addition to the need to test the effectiveness of the access points, the VLAN switching system has to be configured to optimize the use of available radio frequencies. One way William & Mary accomplishes this is to assign MACs to separate VLANs according to whether a student is a freshman or sophomore (they share one VL AN), a junior or senior (they share another), or a faculty or staff member (who share yet another VLAN).

In addition, the six full-time people on Fenstermacher’s team, with help from a student and a temp, prioritize access based on different types of use within the system’s bandwidth. For instance, peer-to-peer traffic gets less priority than Web traffic. The new equipment in place also helps the system balance the loads on the a, b, and g frequencies. “A lot of monitoring of user load on the system is done on the wired side,” Fenstermacher adds. “And there are a lot of companies available that will do that inherently.”

As an aside, he further notes that power-over-Ethernet switches are the best way to go. “Our old ones weren’t, our new ones are,” he says. “The upgrade has been a huge benefit.”

As the university replaces the system over the coming two years, Fenstermacher says he has learned that five years is probably the optimal replacement span to accommodate new 802.11 protocols and features as they take effect.

He also advises anyone else interested in emulating William & Mary’s success to plan everything out on paper first and plan to install more units than you originally think is necessary, because use will definitely take off. “It’s better to over-cover than under-cover when you start,” he says, and concludes with one last important bit of advice: “I can’t stress enough the importance of documenting everything that goes on.”

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