A report that came out in October, 2011 showed that the number of wireless devices in the U.S. exceeds the number of humans. It's an incredible fact, but it has a downside — all those gadgets in addition to radio and television signals are gobbling up space on the electromagnetic spectrum.
Now thanks to a group of scientists they have given a high profile public show demonstrating how two signals could travel on the same frequency. The solution? Twisting them.
Despite a complicated name — orbital angular momentum, the method is surprisingly simple. They split a satellite dish along its radius, creating two different edges. The signals start at different parts around the circumference of the beam, and therefore the signals travel at different points. If you could look at it, it would look like a corkscrew or spiral pasta.
Professor Bo Thide of the Swedish Institute of Space Physics first had the theory back in 2007 in the journal Physical Letters Review. He and his team even tested it in 2011 with a normal antenna and their modified antenna to send 2.4 GHz (a band used in Wi-Fi) to send two audio signals within the bandwidth of one. They also tested it with TV signals.
So why the public show? It seems that Professor Thide felt like the public didn't believe it could be done and wanted to prove it once and for all. He even staged the even in the same place Galileo — another misunderstood scientist — first demonstrated his telescope in the Palazzo Ducale in Venice.
Crowds gathered to watch Thide explain the experiment and then a "signal received" message when the experiment was complete.
Now that the idea is out in the public sphere, Professor Thide and his team are working on expanding the idea to an industrial solution that could carry more than just two signals on the same frequency.
If the expansion proves successful it will open up growth of the spectrum to carry all of the important signals we take for granted.