Researchers at Rice University have received a $1.8 million grant from the National Science Foundation to test white space WiFi - the use of a broad spectral range including dormant broadcast television channels to deliver broadband Internet service. The five-year project pairs Rice with Houston nonprofit group Technology For All; they will add white space technology to the wide-spectrum WiFi network they already jointly operate in a Houston neighborhood.
Lin Zhong, an assitant professor at Rice and a co-principal investigator in the research project, said one area of study will be to determine how the combination of white space and WiFi can help users extend battery life and get improved reception. The research will also examine potential energy savings derived from powering down WiFi nodes and covering large portions of the network with a small number of white-space transmitters during off-peak hours. Zhong said, "White space and WiFi have quite complementary characteristics. While a WiFi node can provide a higher data rate, a white space node can cover a much larger area. The project will study how a dynamic network architecture can combine these strengths."
White space refers to the unused frequencies that are set aside for television broadcasters. Currently WiFi networks operate in frequency ranges unlicensed by the Federal Communications Commission; the existing Rice-TFA network operates in frequencies between 900 MHz and 5 GHz. The recent NSF grant will allow researchers to deploy WiFi in the licensed but unused TV spectrum between 500 and 700 MHz. According to researchers, the new network will dynamically adapt its frequency use to meet the coverage, capacity and energy-efficiency demands of the network and its users.
"Engineers often refer to the UHF frequencies between 500 and 700 megahertz as being the beachfront property of spectrum," said Edward Knightly, principal investigator on the project and a professor of electrical and computer engineering at Rice. "As many WiFi users know, you don't have to move very far before you drop out of a hotspot. Low-frequency TV signals are different. One more wall or one more tree is not going to push you beyond the reach of the network. That's why rabbit-ear antennas served most of the country quite well before cable and satellite came to dominate the market. ... The use of white space should eliminate many of the problems related to WiFi dead zones so the overall user experience should improve."
According to information released by the researchers at Rice, the new grant will pay for the development and testing of custom-built networking gear as well as smartphones, laptops and other devices that can receive white-space signals and switch frequencies seamlessly.