The capacity boost from implementing 802.11n access points will make Wi-Fi “the primary means of accessing the network,” says Duke’s Kevin Miller.

Feb 18 2008

Warm Embrace

A few schools -- in the vanguard -- adopt the unfinalized 802.11n Wi-Fi standard.

A few schools — in the vanguard — adopt the unfinalized 802.11n Wi-Fi standard.

Most universities and colleges today offer their students and faculty a combination of wired and wireless network access. As of late, when there’s a choice, users pick wireless.

“We historically had provided wired networked ports, and for a long time, those in the library were getting the heaviest usage,” says Kevin Miller, assistant director of communications infrastructure in the Office of Information Technology at Duke University in Durham, N.C. But when OIT did a review of node use late last year, the library ports proved a bust. “We found out that pretty much no one was using them at all,” Miller says.

But while Wi-Fi is popular because of its convenience, it has some pitfalls, such as relatively slow data-transfer rates, dead spots and interference. To address these problems, Duke and a few other universities have begun implementing access points built to the 802.11n Wi-Fi standard — despite the fact that the standard is still in draft.

The reasons for moving ahead can be calculated in hard figures based on faster throughput, longer range and reduced interference. The challenges are more amorphous and involve having adequate staff to manage a network capable of supporting a wide mix of Wi-Fi devices and figuring out how to handle the cost.

Ready to Roll

For many, the increased power and range of 802.11n is too appealing to wait for the final release. “The effect of that raw capacity increase will be to move wireless from being just a welcome and useful addition to our wired network, to being the primary means of accessing the network even when the application requires rich media like video and audio,” says Miller.

Duke piloted 802.11n in one residence hall last summer, with eight Cisco Systems access points covering 16,000 square feet. The success of that pilot led Duke to look at other 802.11n implementations where the upgrade would provide the most benefit. The next project will likely be in a new teaching facility and will focus on multimedia access.

Miller says the speed of 802.11n is the primary reason that OIT plans to deploy an 802.11n setup for the facility. “In a classroom setting, it would be very disturbing to faculty and students if they were asked to access a resource and they had to wait five minutes for it to come up.”

Dan McCarriar, assistant director of network services at Carnegie Mellon University in Pittsburgh, agrees that the new standard will change the way schools use wireless networking. “Up until now, with 802.11a/b/g, we were able to offer a wireless network that was reasonably functional for many of the standard and common applications like e-mail and Web surfing,” he says. “But being a shared medium, wireless wasn’t fast or reliable enough for all applications. There were times when you’d get a lot of people in one place when even basic applications didn’t perform as well as we’d like.”

In addition, McCarriar notes that certain high-throughput or latency-sensitive applications, such as videoconferencing, functioned poorly on the wireless network. He’s also quick to point out that 802.11n isn’t some magical panacea, but its faster data rate and range will eliminate many of the problems the university experienced with products built to the older standards.

Carnegie Mellon’s IT team is conducting a site survey of the entire campus with the goal of deploying a next-generation wireless network by the end of the year. With 802.11n, “the wireless network will become the primary network on campus for a wide range of applications,” McCarriar says.

From the Mouths of Users

Although network directors calculate the benefits of new Wi-Fi implementations in data transfer rates and range, there’s also anecdotal evidence from users that the new gear provides better service. At Morrisville State College in New York, there’s no question that 802.11n outperforms its brethren, says Jean L. Boland, vice president for IT services. “Our users are amazed at how much faster the wireless network is. Now, our faculty, who have incorporated the use of notebooks in their curriculums since 1998, can include high-bandwidth applications and content, like streaming video, in their lectures because 100 percent of our classrooms now have wireless coverage.”

Last summer, Morrisville replaced its legacy wireless network. This upgrade began with 10 802.11n access points and 710 802.11a/b/g APs for the start of the school year. Then, in October, the school replaced all the 802.11a/b/g APs with 802.11n APs to provide coverage for the entire campus.

Besides providing improved network performance and coverage, the new Wi-Fi APs provide significantly faster access, Boland says. “We’re also pleased with the ability to load balance between the access points. Plus, the single-channel architecture and management console means we are able to minimize our staff support requirements for the new wireless network.”

The early adopters, such as Boland at Morrisville and Miller at Duke, say they are not worried that the standard has not yet been finalized. They point out that as the draft has gone from version to version, upgrades from vendors have been either automatic or accomplished through downloads. Plus, most of the industry is looking at 802.11n as a done deal, Boland points out. Even the notebook makers are now beginning to provide network cards that support the 802.11n specs. Many new Lenovo ThinkPads (which is what Morrisville students receive) and most other notebooks have Wi-Fi cards that support 802.11n. “Many companies are banking on a firmware upgradeable 802.11n final standard. And the Wi-Fi Alliance is certifying 802.11n Draft 2 products. So we are confident in our decision to go with 802.11n Draft 2 wireless,” Boland says.

In fact, early adopters say they are more concerned about how they will deal with their legacy APs and devices. “We have to continue to support older standards for a long time to come,” says Boland.

At Morrisville, all incoming freshmen receive ThinkPads with 802.11n support; the upperclassmen have notebooks without that same support. Plus, there are other devices, such as personal digital assistants, that IT must support and that have a/b/g cards. “We will support everything our students bring here,” says Boland. So for the foreseeable future, all Morrisville APs will have two radios: one for 802.11a/n (in the 5-gigahertz frequency) and the other for 802.11b/g/n (in the 2.4GHz frequency).

The Lag Effect

A related challenge for Boland’s staff is the necessity to support multiple drivers and Wi-Fi cards. “We’re going from a pretty homogenous legacy wireless network — one driver, one wireless PC card — to one with a multitude of devices and drivers,” she says.

But ultimately, school network directors see the new standard as a way of providing the best possible network services to their students and faculty. None expect to recoup an immediate return on investment. Duke’s Miller says a gradual decrease in wired ports, however, will reduce costs in the long run.

Ultimately, it’s about making the smartest technical decision relative to cost, says Carnegie Mellon’s McCarriar, who had already budgeted $4 million for a major network overhaul. “I have the funding now,” he says. “It makes sense to buy the most advanced network available at this time.”

Fast and Far

802.11n calls for data transfer rates of 248 megabits per second, compared with 54 Mbps for 802.11g products, and the distance range is about 230 feet, compared with about half of that for 802.11g.

The Juice

A final unknown for 802.11n is the power requirement.

Virtually all campuses use Power over Ethernet (PoE) to juice their 802.11a/b/g wireless access points. The added power requirements for 802.11n APs may force schools to revisit their power options.

Morrisville State Vice President for Technology Services Jean L. Boland says her campus’ new 802.11n APs are smart and allow 2 x 2 antenna configuration to use a PoE power supply. But if the antenna configuration increases to 3 x 3, the college will need to look at other options, such as PoE Plus, which may add to implementation costs.

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