Campus Technology Focus

May 5, 2011

Campuswide Wireless Saves Money for Salem State University

Beyond infrastructure costs, one of the biggest challenges in deploying wireless networks on campus is installing and managing the thousands of access points typically required. Running cabling through historic buildings also presents special challenges to educational institutions. Each wireless access point, after all, still requires a wired connection and a dedicated gigabit port in order to connect.

Salem State University, located in the historic city of Salem, Massachusetts just north of Boston, has addressed its wired-wireless problem by drastically reducing the amount of wireless infrastructure devices required to support its wireless network. The university, which covers 115 acres over five campuses within the Salem city limit, serves 10,000 graduate and undergraduate students. It had struggled to support its many users, but has recently solved its connectivity and density issues.

Rather than continuing with its previous wireless access points (APs), which served just 30 to 35 users per device, Salem State has switched to a wireless solution from Xirrus, a California-based Wi-Fi technology company that specializes in high radio-density Wi-Fi devices called Arrays, which allow connectivity of up to 200 users on the 4-radio Array and over a thousand users on the larger Arrays.

Xirrus Arrays, sometimes described as access points on steroids, in that one Array can replace many access points. The Arrays include 4, 8, 12 or 16 integrated radios, coupled to high gain directional antennas that provide greater range and overlapping coverage to resiliency. The Arrays ability to cover four times the area of traditional APs greatly reduce the number of devices required to create a seamless 802.11n wireless network. Because the Xirrus Arrays deliver much more range, coverage, and bandwidth per device than a traditional access point, Salem State has been able to cover the campus with just 270 Arrays in 30 buildings, or about ten Arrays per building.

Brian Helman, Salem State University’s ITS director of networking services, says the Xirrus technology has saved the university from installing hundreds of access points. “We have just under 300 [Xirrus] Arrays installed,” he says, but would probably need as many as 1,000 access points from a competitor using traditional wireless technology.

Helman is using mostly Xirrus 4-radio units, the XN4 model. Depending on the size, shape, and capacity requirements of rooms either an XN4 or an XN8 are deployed. The XN8 is an 8-radio model, used where there is a higher density requirement. “We can handle a huge amount of space with a single-8 radio Array,” Helman says. “That’s good, because I have a very small staff.”

The Arrays are more expensive than traditional APs, he concedes, but that is expected as they cover a larger area and higher density of users with a single device. In addition, savings come from more than just purchasing fewer units. There’s also huge savings on the considerable cost of running wiring to each unit on campus. That wiring cost has been cut by more than half, and there are accompanying reductions in costs by mounting and maintaining fewer units. Other significant costs savings are the need for fewer switch ports, especially with 11n requirements for gigabit speed ports.

The Salem State campus is fully wireless inside its 30 buildings now, including residence halls, classrooms, libraries and auditoriums, along with three sports fields. This summer Helman plans to extend wireless coverage to outside areas where students congregate, along with point-to-point coverage to a few difficult-to-reach buildings.

The campus still maintains wired ports throughout, including the dorms, where Helman says that students still use for some applications.

Xirrus assisted Helman and his staff during the planning process, performing active site surveys to determine coverage requirements and Array placement. After install Xirrus performed post install-surveys to verify coverage and operation. There was some post-installation tuning, Helman says, as with any wireless project, but it has proved to be minimal. Xirrus’ also offer a compressive management tool, the Xirrus Management System (XMS). It can view the complete wireless environment including Arrays, Clients, potential threats and even monitor the physical layer RF environment for interference.

Because of the multi-radio, high gain antenna design, a Xirrus Array can be deployed inside a building but also still have the ability to penetrate exterior walls and serve users outside. That helps with some of the historic buildings on campus in particular. “Those older buildings are tough to wire—the less wiring I can put in there the better,” Helman says.


If you are interested in deploying a high performance Wi-Fi solution, please contact Xirrus at: [email protected]

2101 Corporate Center Drive
Thousand Oaks, CA 91320




To unsubscribe from future mailings from the sponsosr in this message, please click here