But Italian astrophysicist Fabrizio Tamburini says a solution may lie in making better use of the frequencies already in use. In a recent paper, he demonstrated a potential way to squeeze 100 times more bandwidth out of existing frequencies.
The idea is to twist radio waves like corkscrews and create multiple subfrequencies, distinguished by their degree of twistedness. Each subchannel carries discrete data sets. “You can tune the wave with a given frequency as you normally do, but there is also a fingerprint left by the twist,” Tamburini says. He and Swedish colleague Bo Thidé hit upon the approach while studying waves warped by the immense gravity of black holes. This past June, the scientists set up a custom dish in Venice and successfully broadcast video encoded in both twisted and normal radio waves across St. Mark’s Basin. (Note this type of wave-twisting is fundamentally different from the better-known circular polarization of light.)
The next step is to design small, cheap smartphone antennas that can transmit and receive the warped signals.