FCC paves way for new radios
- By Bryant Jordan
- Jan 07, 2001
Notice of Proposed Rule Making
As the broadcast spectrum becomes more and more crowded, federal officials are looking for new ways to share the airwaves.
Enter the software-defined radio, or SDR — a frequency-programmable radio developed by the U.S. military. The Federal Communications Commission may attempt to put that technology on the fast track.
The FCC intends to permit manufacturers to change the frequency, power or modulation type of SDRs without going through the long process developed for legacy radio systems. Allen Nogee, a senior analyst of wireless technology for Cahners In-Stat Group, Scottsdale, Ariz., commended the FCC for "using a little foresight and making a judgment" that SDR technology will benefit everyone.
Unlike legacy systems, which are manu-factured to broadcast or receive over specific frequencies, SDRs can change frequencies to work over a less-used part of the spectrum.
According to Nogee, this flexibility also holds the key to another telecom demand — universal interoperability among different radio systems and cellular phones.
Although such interoperability is still years away, the ability to "program" a radio or phone's broadcast frequency and modulation by making changes to its software over the air will add value to SDRs.
Army Col. Michael Cox, deputy program manager for the Joint Tactical Radio System at the Pentagon, said SDR technology will advance communications for military and civilian agencies alike.
"In the cell phone industry, you'll have the ability to go anywhere in the world [with one phone] because you can download the various protocols and operate anywhere," he said. "In military radios, you'll have the ability to go overseas and operate in the frequency bands assigned to you. In natural disasters, police, fire departments, ambulances and the National Guard will be able to load up the same [frequency] and communicate with each other."
The military has led the way in SDR technology, beginning nearly a decade ago with a program called SPEAKeasy. When the Army deployed the system in 1997 during an advanced warfighting experiment, SPEAKeasy's two software programmable channels replicated half a dozen frequencies — including those for UHF satellite communications and cell phones.
According to congressional testimony, SPEAKeasy enabled users to talk with various units on their own frequencies and provided limited data networking capabilities.
Cox said the Pentagon has no concerns about SDR going commercial. "We've been working with industry to develop the standards," he said.
In fact, in a few months the Pentagon will be ready for industry to begin building SDRs for military use. Eventually, industry will take the technology and develop it further.
To a limited extent, SDR technology is already in the public arena. Since 1997, AirNet Communications Corp. of Florida has built base stations for cellular phones using SDR technology, according to Lee Hamilton, company president and chief executive officer.
SDR allows cellular phone network operators to manipulate their spectrums by changing the software at the station, Hamilton said.
"The FCC is taking a forward-looking position," Hamilton said. "They've spent a lot of time reallocating spectrum. Now wouldn't it be easier if you could have the base stations that could add applications onto infrastructure [using software] to make the best possible use of the spectrum?"