Antihydrogen and hydrogen atoms should have the same properties, emitting the exact same frequencies of light, for example.
The same frequencies can be used simultaneously in different areas because a cell phone signal from the ground does not wander much beyond its intended receiving station.
The wireless microphone technology used for Broadway shows and other events uses some of the same frequencies that regulators would like to open up for wireless data.
When sound processors remove the same frequencies and lower the volume a minuscule amount, our brains begin to perceive the sound as coming from behind.
The broadcasters can fit multiple digital channels into the same frequencies that used to carry one analog channel.
Females in a nonbreeding state responded no differently to birdsong than to generic tones of the same frequencies.
Dr. Ryan's colleague Dr. Walt Wilczynski, a neuroscientist, established that the hearing systems of the species Physalaemus coloradorum are tuned to be sensitive to the same frequencies as the túngara ear.
For civilian use, the main benefits are signal clarity and the efficient use of increasingly crowded bandwidth, because scattered signals are less likely to interfere with other transmissions -- even ones on the same frequencies.
"You get people from other states and federal agencies that aren't on the same frequencies as the local people," said Petty Officer Andrew D. Kendricks, a Coast Guard spokesman in Alexandria, La.
If Mr. Tawil's reasoning proves correct, small transmitters on towers could offer a competing and far cheaper service by beaming signals on the same frequencies from the north of their intended subscribers.
But the main thrust of the regulations was to divide up the cellular broadcast band in a way that let competing cellular providers in nonadjacent areas across the country use the same frequencies without overlapping signals, said Mr. Adler, who is now general counsel at Globalstar, a provider of mobile and satellite telephone services based in San Jose, Calif.
