If you listen to Bill Lawrence tell it, IT directors today are at war trying to match their Wi-Fi networks with the amount of data that users want to push back and forth across the Internet. For the IT Project Manager of Georgia Institute of Technology (Georgia Tech), RF management of unlicensed wireless networks is taking a much higher priority these days.
“We are in an arms race trying to keep up with all the new devices that show up. Students expect good Wi-Fi coverage wherever they go on campus. It is not a convenience. It is a real requirement for our students,” Lawrence told DAS Bulletin.
With the number of devices showing up in a venue trending upward, bandwidth pressure occurs on the existing infrastructure. One example of an enterprise trying to keep up with the dramatic increase in Wi-Fi-capable devices is Georgia Tech’s large lecture classrooms, where the university had serious interference issues in trying to serve the influx of students with smart phones and tablet computers.
“We had a couple of 300-seat auditoriums that were receiving heavy use of the wireless network, using omnidirectional antennas,” Lawrence said. “The distribution of clients skewed so that some access points would get heavy use and others would get only a few users.”
The answer to the university’s RF coverage issues was to deploy antennas that direct the Wi-Fi signal, as opposed to an omnidirectional antenna that propagates across a broad 360-degree coverage area. This allows them to use more access points in different sections of the room, not unlike the way cell sites reuse spectrum, without creating interference. Each auditorium is segmented into 12 coverage areas.
To do this, Georgia Tech deployed the TerraWave High-Density 2.4/5 GHz patch antenna from Ventev Wireless Infrastructure, a division of TESSCO, which features a narrow 35-degree beamwidth, minimizing channel-to-channel interference, resulting in increased capacity. The antenna also features a higher gain (14 dBi versus 6-10 dBi) that enables a greater distance between the antenna and users.
“By using the directional antenna we are able to reduce the number of users per access point so they can get more bandwidth,” said Jeff Lime, Ventev vice president. “This is where the opportunity for high density antennas is really showing up. We have challenging environments with increased capacity needs, where adding omnidirectional access points would only lead to more interference.”
Lawrence has also installed a high-density antenna in the courtyard outside the business school on the Georgia Tech campus. He is doing some renovations on residence halls, where he plans to use the high-density antennas in the outdoor commons area.
Currently, Georgia Tech has 105 access points deployed outdoors. When it gets funding, the IT department plans to upgrade all the outdoor wireless networks using high-density antennas, especially in areas where students congregate and want to use their tablets and laptops.