'Cognitive radios' to improve wireless devices
By
Liz Tay
16 September 2008 01:39PM
Tags:
cognitive | radio | researchers | microsoft | knows
Researchers are developing intelligent radios that can sense their surroundings and adjust their mode of operation accordingly.
Dubbed ‘cognitive radios’, the technology is expected to reach the market within five years, finding uses in public safety devices and wireless networks.
Cognitive radios build on the concept of ‘software defined radio’, in which most functions in a radio device are performed by software-controlled digital electronic circuits.
Similar to how a modern day cell phone signs on to different networks while roaming, a cognitive radio is designed to be adaptive to its situation.
“A cognitive radio is aware of its environment, its own capabilities, the rules within which it can operate, and its operator’s needs and privileges,” explained Charles W. Bostian, an Alumni Distinguished Professor of Electrical and Computer Engineering at Virginia Tech.
“It is capable of changing its operating modes in ways that maximise things that the user wants while staying within the rules ... is capable of learning in the process and of developing configurations that its designer never anticipated.”
Adaptive, cognitive radios could enable techniques such as dynamic frequency sharing, in which radios automatically locate unused frequencies, or share channels based on a priority system.
In public safety, cognitive radios also could be used to provide interoperability between various signals and automatically adjust radio performance.
“For example, if its user is inside a building where there is little or no public safety radio coverage, the radio may automatically switch to a VoIP mode and reach the dispatcher through a WiFi access point and a telephone line,” Bostian said.
“These ideas are research topics now, and some of them will soon reach the market,” he said.
“It will mean more business and more equipment to sell for the wireless infrastructure manufacturers. They have nothing to lose and a lot to gain.”
Microsoft is researching the technology’s potential to alleviate bandwidth scarcity in wireless networking through its Kognitiv Networking Over White Spaces (KNOWS) research project.
The project works towards opportunistically accessing unused portions of the TV spectrum, and already has birthed a prototype that scans for unused frequencies by sensing the TV spectrum.
When an open frequency band is located, the device is designed to dynamically switch to it in a way that does not hurt incumbent TV receivers.
“I think dynamic spectrum access will be the first application for commercial wireless services like WiFi and WiMax,” Bostian told iTnews. “There is movement toward doing this in vacant U.S. TV channels.”
According to Bostian, current challenges in the development of cognitive radio are reducing cost and improving battery life.
While the technology is expected to reach the market within five years, it will take twice as long to become commonplace, Virginia Tech researchers predict.