The needed spectrum to carry additional communications
traffic exists, but government-regulated allocations has some of this space
off-limits to wireless providers.
An answer is to share the use of the communications spectrum
superhighways in the sky that already exist.
"However, one of the critical challenges that needs to
be addressed for spectrum sharing is the problem of spectrum security and
enforcement," said Jung-Min "Jerry" Park, Virginia Tech
associate professor of electrical and computer engineering. "The primary
concern is the interference experienced by primary users due to rogue
transmissions by maliciously intended secondary users when the two groups
operate in the same band."