Houston Group Gets White Space Rollout Grant

Houston non-profit group Technology For All (TFA) provides Internet service to Houston's working-class East End neighborhood using a variety of unlicensed spectrum ranging from 900 MHz through 5 GHz. Under a $1.8 million grant from the National Science Foundation, researchers at Rice University and TFA will develop and test custom-built networking gear as well as consumer devices that can use TV band white space frequencies and seamlessly switch between different frequency bands.

"While space and Wi-Fi have quite complementary characteristics," said Lin Zhong, assistant professor in electrical and computer engineering at Rice University. "While a Wi-Fi node can provide a higher data rate, a white-space node can cover a much larger area. The project will study how dynamic network architecture can combine these strengths."

One idea they hope to explore is saving power by shutting down Wi-Fi nodes during off-peak hours and using a few white-space nodes to cover large portions of the network.

"Ideally, users shouldn't have to be concerned with which part of the spectrum they're using at a given time," said Edward Knightly, Rice's principal investigator on the project. "However, the use of white space should eliminate many of the problems related to Wi-Fi 'dead zones,' so the overall user experience should improve."

An ars technica article, Prof's bring free "Super WiFi to working-class Houston said the area where they plan to offer the service has five empty TV channels available.

However, under the latest FCC rules, that may not be the case.

The Show My White Spaces tool from Spectrum Bridge showed only one channel available for fixed devices: Channel 2. There are no channels for portable 100 mW devices, and only nine channels for 40 mW portable devices in Houston. If the Spectrum Bridge analysis is correct, TFA and Rice will need to get a waiver of the rules to allow fixed operation on one or more of the eight channels (four VHF and four UHF) reserved for wireless microphone use.

To see if more channels were available east of Houston, I shifted the analysis to Beaumont, Texas (about 75 miles distant) and found two low-band VHF channels (5 and 6) that were available for fixed white space devices, and eight UHF channels that could accommodate 40 mW portable devices.

Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.