Doug Lung /
University Researcher Devises TV Spectrum Sharing System for Cell Networks
Details sketchy, but highly directional antennas may be the key
Mai Hassan, a PhD student in the Department of Electrical and Computer Engineering at the University of Columbia, has developed a way to allow cell phones to simultaneously use frequencies occupied by TV broadcasters. The study was published in the journal IEEE Transactions on Wireless Communications.
Mai Hassan explained: “I proposed a more effective way to use any channel in the neighborhood, even if those channels are being used by radio or television stations. The challenge was finding a way to make sure the cellular signals didn’t interfere with the people using those channels in the first place.”
I was not able to find a copy of the study on-line and only limited details are available on how Hassan's solution would work. From the information I have located, it appears the system relies on highly directional smart antennas that beam the signal directly to the receiver while avoiding any interference to the original broadcast signals. Given the small size of smartphones, it’s difficult to get the required directivity from one phone. Hassan appears to have come up with a way to combine the signals from multiple smartphones in different geographical locations “to cooperatively achieve the same constructive/destructive interference pattern.
See the University of British Columbia news release New technology can prevent cellular overland, dropped calls
for more information.
A short YouTube video of Mai Hassan pitching her solution
is also available.