The world is running out of wireless spectrum. This is a bit of a problem, since wireless devices are proliferating like rabbits, but physics dictate that the wireless spectrum is finite. This will ultimately present a bit of a problem for mobile broadband.

If you’re a telecom giant, you can bid on small blocks of spectrum when they become available, or you can purchase another telecom provider to gain their spectrum. The deal struck by Comcast and Verizon and finalized last summer allowed Verizon to buy unused spectrum for $3.6 billion; and in October AT&T (News - Alert) received approval to operate in Sirius XM’s spectrum.) If you’re not a giant telecom company with deep pockets, you’ll need to look elsewhere.

There has been much talk of using the “white spaces,” or the frequencies allocated to a broadcasting service but not used locally. Despite the opposition from some television broadcasters who feared interference, the FCC (News - Alert) voted in 2008 to allow the use of white spaces for extra spectrum. But white space, too, is finite.

Google thinks it may have a solution: something called spectrum sharing.

“One way we're trying to help researchers and other stakeholders identify available spectrum is through dynamic spectrum sharing. Spectrum (News - Alert) sharing allows devices to use spectrum when it is not in use by someone else simply by checking a data base,” blogged Google’s Alan Norman on Monday.

While it sounds great in theory, perhaps you are old enough to remember “party” telephone lines. In case you’re not, a party line was a telephone number shared by many households. Occasionally, when you needed to make a call, you’d pick up the receiver only to find that Mrs. Nesbitt next door was on a two-hour gossip fest with her daughter in Poughkeepsie, so your call had to wait until you heard a dial tone. The party line phone served a few purposes: for starters, it saved money over a private telephone line. More importantly, it was the number one source of gossip in the neighborhood, as everyone knew everyone else’s business (listening in on others phone calls was a great way to pass an hour on a rainy afternoon). Finally, it made you pay more attention: in order to know whether a call was yours or someone else’s, you had to listen carefully for your assigned ring tone.

While spectrum-sharing on wireless devices sounds like a great idea in theory, particularly for smaller companies who simply cannot compete with the telecom giants due to lack of spectrum, it brings up thoughts of having to share spectrum with the teenager next door who watches reruns of “Firefly” until his nose bleeds, or the couple who insist on reading “The Jungle Book” over their smartphone to their grandchildren every night at bedtime.

In reality, spectrum sharing could work, at least at the federal or commercial level, according to an article that appeared in the New York Times last year. Wireless carriers and government agencies could collaborate, using a system that would scan and maintain a database of who can use what when.

“For example, the military might have radio spectrum it uses for communicating at a bombing test range, but when that test range is not in use, a smartphone would be able to pluck a signal from that spectrum. Ideally, if the military needed to use the test range, it would gain priority over commercial users,” wrote the Times.

The President’s Council of Advisors on Science and Technology (PCAST) recently completed a study on spectrum sharing and concluded that, if properly managed, spectrum sharing could multiply the capacity of existing spectrum by a factor of 1,000.

Of course, spectrum sharing is unlikely to be done at an individual level (in other words, you probably won’t have to book an appointment to send a data or voice packet) and will instead be done by carriers using blocks of spectrum. But those of us who still remember the days of sharing telecommunications with others will remain a little skeptical until we see it work.