Wireless Takes Over

• By Paul Korzeniowski
• 02/01/08

WiFi has become a primary (if imperfect) networking option for many academic institutions. But get ready: Recent advances are positioning WiFi to become your academic communications hub.

AFTER STARTING OFF as a simple way to provide users with access to internet resources, WiFi networks have evolved to become an important communications cornerstone for a growing number of academic institutions. Not only have colleges been working to make these networks available across their entire campuses (or at least pretty close to 100 percent available), but wireless communications also have begun to emerge as a primary mode of carrying video and voice transmissions. As a result, WiFi network usage is becoming as common as wired connections on some campuses.

While making dramatic inroads, the technology's evolution has encountered a number of significant hurdles, a few of which vendors still need to clear: First, in order for WiFi networks to span campuses, their management functions need to be enhanced, a step that has already taken place. Next, to carry video transmissions, their throughput needs to be upgraded to higher speeds, something that is still a work in progress. Finally, to support voice communications, they need to be able to allocate bandwidth in a more granular manner, another task still evolving. Bottom line? Though imperfect, WiFi has become a primary networking option for many academic institutions.

Emory University, in Atlanta, GA, is a perfect example of the dramatic change in the way academic institutions are using WiFi networks. After determining that students needed more wireless options than the university was providing, campus administrators and technologists launched Emory Unplugged, a massive project designed to overhaul and expand the institution's wireless services, so that they would be available campuswide.

"Incoming students are technology-savvy and expect wireless connections to be available wherever they roam on campus," explains Stan Brooks, wireless architect for Emory. The university, which began expanding its network footprint at the beginning of 2005, currently has more than 1,000 access points (APs) running across campus. Wireless connections are now available in many of Emory's academic buildings as well as in its 55 residence halls.

As WiFi Expands, Problems Emerge

Emory is not unique. At many other higher ed institutions, dozens, hundreds, and even thousands of APs are popping up. Yet as the networks grow, many IT departments have trouble keeping pace, and there's a good reason for that. Traditional methods of deploying wireless networks focused on standalone, intelligent APs. The devices were easy to install, and the vendors' initial focus was to make the systems' wireless signals stronger and the systems' bandwidth more granular through the development of more sophisticated antennas that moved transmissions from users' computers to campus networks. But because the initial design of the APs was centered on standalone systems, making wireless connections ubiquitous has been difficult. Many of the older wireless networks featured "fat" APs (running a lot of installation and management software), which IT staffers found difficult to deploy and manage. Typically, each AP's security policies had to be individually configured, so deploying these connections was a manually intensive undertaking. In the case of Emory, the school needed five full-time engineers to configure and manage its APs. Not surprisingly, many other universities quickly discovered that deploying, upgrading, and managing these distributed devices on a wide-scale basis was complex, time-consuming, and expensive.

Another limitation university technologists uncovered: The networks were not robust. APs often dropped connections as users moved from one area (or AP) to another location. One reason for this is that APs with overlapping coverage areas sometimes could not operate on the same channel. To try and avoid such problems, university technicians completed site surveys (often performed simply by walking around campus and testing connections) to determine coverage patterns. Then they re-stationed their APs for minimal interference.

However, despite these steps, the process sometimes resulted in coverage gaps, and users were no happier. Many mobile workers, for instance, had to reauthenticate themselves with the network as they moved out of one AP's coverage area and into the next, and the available bandwidth dropped as they came closer to the boundary lines between coverage areas. In response to the connection problems, the IEEE devised the 802.11r fast-roaming standard (which enables users to authenticate themselves at one AP and have that information move to a neighboring system), and the 802.11k standard for radio resource management (which speeds up network handoffs between APs).

APs Go on a Diet

Another change vendors made was to enhance their systems so that they could be managed from a central location. They moved away from fat APs to thin ones— rather than producing APs loaded with intelligence, the suppliers built devices that relied less on the AP and more on central switches. Equipment from Aruba Networks, for instance, now allows Emory University to monitor all of its connections from a central console, and use a consistent set of management tools. Consequently, instead of the five full-time technicians, only two network engineers are now needed to configure and manage the school's wireless network.

Caught in the Switch

In the fall of 2004, to accommodate 6,000-plus undergraduate students and the rest of the campus community, Villanova University (PA) administrators decided to expand the reach of the campus wireless network. Behind the decision was a change in the institution's computer policy, requiring all freshmen to have laptops. But as campus technologists began to expand the school's wireless LAN footprint, Villanova (like Emory) found itself caught in the transition vendors were making.

"We started out with some older WiFi equipment, but with it we could not deploy and manage our network as easily as we wanted to," recalls Robert Mays, Villanova's director of networking and communications. As a result, he says, the university switched from its traditional equipment supplier to wireless products from Meru Networks. Today, the university has about 500 thin client, centrally controlled APs installed, serving all of its academic buildings and about one-third of its residence halls.

Much like at Villanova, in the fall of 2005 Fitchburg State College (MA) mandated that its freshmen use laptops. In this case, though, being "caught in the switch" not only resulted in providing users with easy network access, but the new wireless network also came to the aid of the campus's IT department, which had been seeking a networking solution to an ongoing problem at Fitchburg: Many of the university's buildings were 75 to 100 years old, so adding wired connections was proving not only to be difficult, but even impossible in some cases.

"We could put, at most, two wired data ports in many of our classrooms," Charles Maner, the college's CIO, can now admit. Wireless was the better option because it required minimal changes to the antiquated infrastructure, he explains.

To support its initiative and provide wireless connectivity, the college selected RoamAbout 84000 wireless switches and RoamAbout access points from Enterasys. Currently, about 150 access points provide connectivity in classroom buildings, the campus center, the library, the dining hall, and other common areas spread across the college's 31-acre campus. Battling Bandwidth Hogs As wireless usage has spread on academic campuses, bandwidth has become an issue. That's because as an increasing number of users rely on these networks, more bottlenecks can occur. In general, wireless networks have sufficient bandwidth to support most data applications, but recently, as more universities experiment with video applications (which usually are bandwidth hogs), they find themselves chewing up hundreds of Kbps, or even multiple Mbps, of bandwidth. So far, video usage has been limited and the early results promising.

Villanova's faculty, for example, has begun tinkering with real-time learning applications (some of which feature video streaming) without any adverse effects. And the Creighton University (NE) wireless network—which relies on Cisco Systems devices and has 10,000 users including students, faculty, and support staff—also has started to run video transmissions over WiFi.

According to Creighton VP/IT and CIO Brian Young, "We have a number of training classes that rely on video transmissions. Many of our journalism classes also use various types of video clips, and faculty video-stream a lot of movies as part of their presentations." Young reports that his wireless network has not had problems handling the highbandwidth transmissions. Meanwhile, back at the dorm, video has taken over on many campuses nationwide: At some colleges and universities, classroom capture video is available for students who missed class, wish to review recent lectures, or want to pull up archived lecture material. That's all well and good, but after class, leisure time is video time and students' PCs often replace their TVs. Video applications such as YouTube are rapidly gaining popularity, and students can now download movies or video clips via a growing number of peer-to-peer (P2P) applications, or even via schooloffered services. In some cases, enterprising students establish legitimate (and in some cases, illegitimate) businesses via these applications and can continually download hundreds of MBs or GBs of data during the course of a day.

How are universities and colleges to stem this growing bandwidth drain? They can address these new bandwidth challenges in a couple of ways: First off, campus technologists can now boost the speed of the wireless networks— a new standard is emerging that doubles WiFi's top speed (see "Update: 802.11n"). Another option: ratcheting up their management functions.

"In order to prevent video transmissions from overrunning our network, we limit the amount of data students can transmit via P2P applications," says Matthew Arthur, director of network technology services, enterprise networks at Washington University in St. Louis. The university has 1,000 Meru Networks APs supporting 5,500 undergraduates on its campus and at a few satellite locations, and expects to double the number of APs as part of its plan to make wireless connections available campuswide in the next 12 to 18 months.

Marrying VoIP to WiFi

In addition to video's growing popularity, voice over IP (VoIP) has become more common among higher education institutions. It has the potential to enable universities to deliver more sophisticated voice applications while cutting their telecommunications costs. With both WiFi and VoIP gaining momentum, network managers have been looking at ways to "marry" the two; the duo thrives in pockets where mobility and instant communication are at a premium.

"The first place where we see a need to run VoIP over WiFi is in our medical school," says Washington U's Arthur, adding that the staff and students at the hospital are often on the move but need to be contacted quickly in case of an emergency. The university plans to test VoIP features this summer.

Still, as academic institutions examine running VoIP over WiFi, they see a couple of potential problems. First, technologists need to look carefully at the handsets capable of supporting these transmissions, for this area has been evolving slowly. IP PBX suppliers such as 3Com, Avaya, Cisco Systems, and Polycom via its SpectraLink acquisition, have designed wireless VoIP handsets, but these products tend to be expensive.

"We talked to Avaya reps about deploying their VoIP solution, but the cost was $2,000 per handset," reports Fitchburg State College's Maner.

One emerging option is WiFi cell phones that support both WiFi and cellular transmissions. Convenience is a major benefit with these devices; after all, users would prefer to work with one device rather than a couple. Another plus is that users can move from outside to inside, and vice versa, without experiencing dropped calls. In addition, there are potential cost savings for universities and colleges. In certain cases, intra-company cell phone calls account for 50 percent or more of an institution's monthly cellular expenses. But by offloading those calls to a WiFi network, academic institutions can lower their operating costs by 10 to 20 percent.

Unfortunately, these WiFi cell devices are just starting to make their way to market. And because only a few of these devices from vendors such as Motorola, Pantech, and Samsung are shipping, they too have high price tags at present, ranging in cost from $400 to $1,000 or more. Another challenge is that these handsets tend to drain their batteries quickly. But keep your eye on the evolution of these devices as battery life increases, and costs come down.

Another Problem: Transmission Difficulties

As academic institutions start to move beyond data-only transmissions on their networks, the differences between voice and data communication become clear. With the latter, the order in which information arrives is not important. In fact, data are broken up into small pieces, sent in many different directions, and then recompiled at the receiving site. The underlying 802.11 infrastructure makes a best effort to keep it together. While the network tries to send information in the proper order, it does not guarantee that is the case. In fact, in many cases, transmissions will experience delays and encounter jitter, so the transmission order can become a bit jumbled. Normally, it comes together in the end, and the few seconds or split seconds of disarray is not particularly of note to the receiver.

Voice and video applications are not as forgiving, however. They require a feature dubbed quality of service (QoS) where the order is guaranteed, and the likelihood of delays and jitter are eliminated or, at the very least, minimized. If a university runs a wireless network without QoS, and someone downloads a large file, that download can overload the wireless network, lower the quality of voice calls, and even knock a few conversations off the airwaves completely. Understandably then, "QoS is a major concern for us as we begin to deploy VoIP on our WiFi networks," notes Arthur at Washington University.

Most of us are aware that the IEEE has been working on this issue since the turn of the millennium, and ratified the 802.11e standard in 2001. This specification allows packets to gain bandwidth priority by defining four classes of traffic (voice, video, best effort, and background), each with its own queuing ability. The idea is that the applications tell the network how much of a delay they can tolerate, and then the network sets aside bandwidth for them accordingly. Theoretically, when an AP sees a voice application, it will give those packets top transmission priority.

Who Sets Network Priorities?

While the 802.11e standard is an improvement, it has limitations, however. One problem is that the power to request different priority levels resides in client systems. As a result, a user has the ability to mark an application such as an e-mail as "high priority," and have bandwidth set aside for it. In larger deployments, though, more control will have to reside in the IT department in order for the network policies to be effective. What's more, although the network makes a best effort to ensure network bandwidth is available, it stops short of guaranteeing that it can deliver that bandwidth.

Despite those limitations, the initial results from VoIP/WiFi deployments have been promising. Emory University has deployed about 150 VoIP phones on its WiFi network. "We are still in an early stage of rolling out and testing VoIP," says Brooks at that institution, "but at least initially, there have not been any problems with the voice quality."

WiFi usage is now expanding across college campuses as many colleges and universities move to provide their campuses with 100 percent wireless network availability. Clearly, as academic institutions put the finishing touches on wireless network rollouts, they are looking for ways to expand their usage of these networks. And where video transmissions are making their way onto these networks, voice communications are soon to follow, say the pundits. Wireless is quickly becoming a common rather than a niche technology.

Maner at Fitchburg State puts it succinctly: "For us, there has been a significant increase in how often our users work with wireless connections, and that has led to a lot less stress on our wired networks."

::WEBEXTRAS ::
The University of the South (TN) expands wireless network across its 10,000-acre campus. White paper: The Economics of Convergence for Higher Education Institutions.