Wireless & Moblity

'N' is for Now!

• By Linda L. Briggs
• 11/01/08

Driven by student demand, higher education is leading the charge to 802.11n. With final approval of the emerging standard tantalizingly close, some institutions are already rolling out 802.11n networks, and sharing best practices.

THE LEAP IN WIRELESS LAN standards to 802.11n is a WiFi upgrade so new it hasn't yet garnered final approval from the standards committee. Although that approval won't come until next year (vendors are currently building to a "pre-n" standard), there are plenty of notebook computers out there capable of running 802.11n. That means your students will soon be appearing on campus ready and able to take advantage of an 802.11n network. What's more, with 11n access points able to step down to accommodate devices running earlier wireless standards, an 11n network can serve virtually everyone.

The emerging "n" is generating excitement because it represents a major step up from previous wireless WiFi standards such as the most current 802.11g. Although many factors determine the final connection speed to a wireless network, 802.11n promises real increases in that speed: potentially, 300 Mbps of throughput, compared to 802.11g's 54 Mbps, max. Top raw connection speeds for wireless are largely theoretical and seldom achieved, but even a portion of 802.11n's potential can exceed the speed of current wired connections on many campuses.

Still, speed is only part of the 802.11n equation. The new standard also boasts far better signal coverage and includes other complex enhancements that can make network design and placement of access points easier, and can greatly improve system performance beyond speed. In fact, the sort of wireless speed 802.11n offers makes it possible to consider the wireless network for high-bandwidth applications that currently require wired connections, such as demanding video applications, multimedia, collaboration software, applications that require large photo or sound files, and even voice over IP (VoIP). And with tested security standards in place for wireless, such as the certified WPA2 (WiFi Protected Access), many of the security concerns around wireless are being addressed, opening the door for more wireless implementations.

Depending on the network and the intended use, 802.11n's potential speed also makes possible that holy grail of wireless: complete replacement of conventional wired networks.

As has been true in the past with wireless technology, higher education (largely driven by its high-demand student clientele) is leading the charge to 802.11n. With a final standard tantalizingly close, campus IT departments planning either new rollouts, or upgrades to their WiFi networks, are wrestling with whether or not to jump to 11n. Some colleges and universities already have deployed or are in the process of deploying 802.11n technology, forging benchmarks, and creating best practices for others. Since an 802.11n network can offer new configuration challenges and considerations, such experiences are worth considering.

A Sample of Groundbreakers

Wireless pioneer Duke University (NC) set an example this year with a very large 802.11n deployment. After a limited pilot last fall, in February Duke announced a sizable 802.11n rollout of 2,500 access points from Cisco Systems. The university actually is carrying out a one-to-one replacement of existing 802.11a access points, beginning with residence halls and eventually giving Duke's 25,000 students campuswide access to the zippy new network. One clear indicator of Duke students' desire for wireless: Wired ports included when the university erected a new library six years ago were receiving almost no usage.

Wayne State University (MI) is another 802.11n leader. This summer, WSU installed a Meru Networks 802.11n wireless network on its main campus in the heart of Detroit. The new network-- which replaces an eight-year-old Proxim Wireless-based wireless network that offered a mix of a, b, and g coverage-- includes hundreds of access points so far.

Though student expectation is always top of mind, better manageability is behind some 802.11n deployments. Managing the wireless network is a central focus for the University of Minnesota- Twin Cities, which is rolling out a whopping 9,500 access points as part of a new 802.11n setup from Trapeze Networks. With nearly 300 buildings and 80,000 students on two campuses that straddle the Mississippi River, the university currently serves 10,000 wireless users a day, and expects that number to grow exponentially over the next several years, according to Louis Hammond, assistant director of networking and telecommunications services. The Trapeze network will replace a range of different hardware and wireless systems that made wireless network management difficult at best. In choosing 802.11n, reports Network Design Engineer Steve Fletty, "We wanted to invest in something that's going to be around for a while."

A smaller but no less essential installation plan is the Aruba Networks 802.11n network deployment that Ohio Wesleyan University has recently launched across its Delaware, OH, campus. Via some 400 access points, the new network will provide the liberal arts university's 1,850 students with wireless access throughout the campus, including academic, administrative, athletic, and residential facilities (some of which were not covered by the previous wireless network).

Fact is, residence halls are a common starting point for 11n deployments, because dorms are an area where portper- pillow technology can be expensive, yet where students often ask for pervasive, high-bandwidth coverage. In New York City, Barnard College of Columbia University is rolling out an 802.11n wireless network to its student resident halls. The school plans to deploy some 150 Meru access points across five dormitories, then continue the deployment in 2009 to include additional dorms and a new social center still under construction. The deployments will ensure that most of the college's nearly 2,400 students will eventually have 802.11n residential wireless access.

Building-by-Building

What makes 802.11n a good choice for universities considering a completely new wireless deployment? At The University of Tennessee-Knoxville campus this summer, the bleeding-edge demands of the business school drove the choice of an 802.11n deployment in a new building. "N really came to the rescue in this highdemand environment," says Network Architect Philippe Hanset.

The business school's heavy technology usage-- including the requirement of laptop use in classrooms-- and a request for "the latest and greatest in wireless" during planning for a new building, led Hanset to consider making the business school the pilot for an eventual campuswide 802.11n network. As the new wireless standard rapidly matured over the past year, he conducted extensive research with various vendors, then selected Aruba Networks' 802.11n technology. The university, which is currently running mostly 802.11g in its network across campus, will move entirely to 11n over the next two years. Eventually, says Hanset, all of the university's 26,000 students will be served by 2,500 access points and three centrally located controllers.

Hanset admits there have been problems with the current wireless network, a carefully planned campuswide 802.11g layout with 802.11a for better coverage in high-use areas. "Even with this design, we were lacking capacity in some areas," he concedes. The new APs will be deployed campuswide in a one-on-one replacement strategy with current access points, so that existing wiring can be reused, Hanset explains. And because n's range per AP is so superior, coverage problems with the current network should disappear. Rather than a blanket upgrade, Hanset will follow a building-by-building approach, first converting those buildings with the highest demand for wireless uses. Further savings will come as he recaptures costs by reusing 11g access points to replace failed APs elsewhere, as the upgrade proceeds. Going forward, he says, "We will not buy a non-n AP."

The network architect says he chose Aruba because of the compact design of the access points, the relatively low power requirement of the APs (higher power requirements can be an issue with 802.11n access points), and because the school already had made an investment in Aruba wireless technology in its dorms. Certainly, cost can be a factor in any 802.11n project, since controllers and access points are relatively expensive at this early stage. An 11n controller can cost $800 or so, depending on the vendor, while b/g access points can be obtained at a quarter of that cost. Yet although Hanset sees 11n as more expensive than simply deploying 802.11g in the new building, the benefits, he asserts, make the cost worthwhile. "Once you put in an 11n access point, you can pretty much do anything," he claims.

In terms of speed on the new network, Hanset says he is seeing up to 175 Mbps net throughput under ideal conditions, although the reality will be somewhat slower. Even so, he enthuses, "It's a huge difference" compared to the performance of the previous 802.11g network.

Going Gradual

Another approach to an 802.11n rollout is a gradual one that incorporates earlier standards into access points. Morrisville State College, part of the State University of New York system, has long been a wireless leader for its 3,400 students. Last fall, the college moved to a Meru 802.11a/b/g network in an interim step, then shortly upgraded the campus again, to Meru 802.11n. The college took the extra step, according to VP for Information Technology Services Jean Boland, because the 11n standard wasn't quite ready, but the school needed to move from its old wireless standard immediately, in order to run Windows Vista for its incoming crop of new students. The swap proceeded smoothly, with Morrisville simply performing a one-to-one replacement of Meru access points in the move to 11n. Speed, Boland says, has been noticeably improved under the new standard, especially at increased distances from the access points.

And at Temple University in Philadelphia, long known for technology advances, the gradual approach to 802.11n is underway, as well. Earlier this year, Temple upgraded its law school buildings to Meru Networks controllers capable of a range of wireless speeds-- a, b, g, and n-- and access points running both 802.11b/g and 802.11n. That step will make it easier to eventually upgrade the Meru access points to 11n-only.

In the law school, each access point now uses two radios, one running 11b/g and one running 11n. "For a few hundred dollars, we'll eventually upgrade that second radio to 11n," says Michael Taylor, the executive director of telecommunications at the university.

After experiencing a series of frustrating problems over time with the current controller-and-switch-based wireless network, Taylor ran a proof of concept on Meru's general 802.11a/b/g/n technology in Temple's law school building and saw "immediate improvement." Law students were already heavy wireless users, utilizing the wireless connection for bandwidth-intensive tasks such as taking internet-based exams.

"[Meru offers] a really nice technology that has solved a lot of problems we were having with b and g," Taylor says. Among the many old issues the new network has capably addressed: bad client connections, roaming problems, poor performance, sudden disconnects, and hardware failures at the access points. Taylor reports that the 802.11 law school installation includes 30 b/g APs in two buildings, which are made up largely of small lecture halls seating 60 to 80 people. There also are larger wireless areas such as the open area of the library, lounges, and study carrels.

The telecom director claims the law school installation was relatively simple because the university replaced the existing problematic b/g access points, along with the central controller, one-for-one with Meru controllers and APs. One nice Meru feature, he says, is that the technology assigns a single address to a client connection. If the client roams within the network-- that is, if a laptop or PDA is carried by a student from a study carrel to another area, for example-- it's a seamless move because the device's address doesn't change. With the b/g technology in use before, the signal often was dropped when a client was moved.

Temple also is deploying Meru 802.11n equipment in the university's brand-new medical building. In the multistory edifice, the anticipated speed of the 11n network will eliminate the need for wiring every seat in the 200-student lecture halls, saving money and helping to justify the expense of 11n. Yet there is one challenge as the medical school's 11n network is installed, according to Taylor: Previous wireless access points required a single antenna on the unit, but 11n calls for two or even three antennas per access point. That helps increase range, but can create an unsightly AP that takes up more room than earlier APs, and may no longer fit in allocated spaces. That was an issue in the new medical building, where Taylor was concerned both with aesthetics and the potential for vandalism of exposed access points. To accommodate the larger, three-antenna APs, he says, "You'd need enclosures the size of two shoeboxes. I won't do it. I want [the new APs] in a dropped ceiling, for lower profile." He's now working with Meru on a prototype that will do just that: function within the new building's sleek dropped ceilings.

::WEBEXTRAS ::
Webinar: 802.11n: Strategies for a Successful Campus Deployment
Higher Education Fertile Ground for 802.11n WiFi, ABI Reports

-Linda L. Briggs is a freelance writer based in San Diego. She has written about technology in business, education, and government for more than 20 years.