A New Perch For Wireless Research

A 19-and-a-half-foot antenna just got the best view on Drexel University’s campus. Mounted atop the 205-foot Millennium Hall dormitory, the mast designed by a group of electrical engineers from Drexel, will give researchers a perfect vantage point to test out theories of wireless networking that could do much more than boost your cellular reception.

The antenna’s installation in late March has turned Drexel into one of nine National Science Foundation hotspots for testing a high-powered wireless broadband system called WiMAX.

Among other uses, WiMAX was developed to deliver what cable and communications providers call the “last mile” connection. This means that the WiMAX signal is sufficiently strong over a relatively short distance that it could replace the hard wiring for cable, telephone or internet to the consumer.

For researchers like Moshe Kam, PhD, a professor in the College of Engineering who has shepherded the project for the last three years, getting the antenna installed opens a wide spectrum of research and implementation opportunities. The most important opportunity is to test new ideas about wireless communications, and validate new variations of the next-generation wireless technology in an actual urban environment with real users.

Coverage map that will be tested as part of Drexel's wireless research.
Coverage map that will be tested as part of Drexel’s wireless research.

“We plan to use the communication channel enabled by this antenna to verify coverage models that have been developed already, and to identify and measure any gaps between their performance predictions and actual behavior,” said Kam, who, along with Kapil Dandekar, PhD, also of the College of Engineering, serve as the lead researchers on the project. “We will perform what amounts to a series of stress tests, to see how much load

the network can handle, what ranges are achievable, what kind of interference sources are affecting performance and how to mitigate them. We will measure how much power must be transmitted to guarantee certain performance for the user, and at what point additional resources such as bandwidth and power provide only diminishing returns. These tests will give us actual results, they would validate or challenge theoretical predictions, and they are much more reliable and valuable than numerical simulations.”

The new installation also makes Drexel an important component of an NSF program called Global Environment for Network Innovations. This is a high-speed, high-capacity computing network started in the mid-90s – designed to meet the data transfer demands of research institutions around the country.

Drexel joins a group of eight other research centers,–including Columbia, UCLA, Rutgers and Temple– that are expanding the wireless capabilities of GENI by implementing this WiMAX technology.

The 19.5-foot antenna is affixed to the top of the 205-foot Millennium Hall dormitory.
The 19.5-foot antenna is affixed to the top of the 205-foot Millennium Hall dormitory.

“This new installation means we that will have access to, and become part of, a nationwide network,” Kam said. “Researchers from Drexel and other institutions in the GENI program will be able to request time for their experiments on nodes installed in other institutions. In this manner they would be able to  to compare performance of the same system, with the same technical parameters, in different geographical environments and electromagnetic-signal propagation conditions. The result is likely to refine existing propagation and performance models and improve future commercial designs”

As part of the GENI program, Drexel will also be collaborating with local partners Temple and Rutgers to explore the capabilities of a smart WiMAX network that could adjust to accommodate broadband demand using equipment at all three sites.

“I think one day we’ll see smart-networking of this kind, making near-optimal use of distributed resources and used widely by cable and internet providers,” Kam said. “We are happy to have the opportunity to help pave the way to that goal.”