Improving the security of cognitive radio technology is the goal of Virginia Tech College of Engineering researcher Jung-Min Park, who has received a $430,000 National Science Foundation (NSF) Faculty Early Career Development Program (CAREER) Award to support his research.
The five-year CAREER grant awarded to Park, who is an assistant professor in the Bradley Department of Electrical and Computer Engineering, is the NSF’s most prestigious award for creative junior faculty considered to be future leaders in their academic fields.
"It is envisioned that cognitive radio technology will be used for two-way communications in a wide range of applications, such as communication systems for tactical military forces and emergency responders," said Park.
The other major arena for this technology is the development of wireless access networks that can provide Internet services to rural areas, Park said. The world’s first standard (IEEE 802.22) for wireless access networks based on cognitive radio technology is currently being developed for rural wireless access.
Conventional wireless devices—for example, cell phones and emergency services radios—are built with dedicated hardware that performs signal processing for transmission and reception.
A cognitive radio device uses general purpose computer processors that run radio applications software to perform signal processing. This use of software enables the device to readily change certain characteristics, including frequency, modulation, and transmission power. In addition, the software enables the device to sense and understand its environment and actively change its mode of operation based on its observations.
"Cognitive radio networks can be used to help solve a national problem," Park said.
The radio (or electromagnetic) spectrum is a limited natural resource, and the proliferation and success of wireless devices operating in unlicensed bands has led to overcrowding of those bands of the spectrum. A conventional, hardware-based wireless device can access only one area of the radio spectrum, but an intelligent cognitive radio device can sense and identify "white spaces"—or vacant areas—in the spectrum that can be used for communications.
However, the advantages of this technology can be offset by new security threats that have not been considered previously.
"In a civilian cognitive radio network, the motive of a malicious user might be to simply cause mayhem to other users or to receive notoriety," Park said. "This would be the equivalent of computer hackers."
Malicious users also could try to extort money from providers who operate cognitive radio networks and services. In a military setting, an adversary could try to bring down a network or interfere with its communications to gain a tactical advantage.
"My graduate students and I plan to conduct an in-depth investigation of critical security issues in cognitive radio systems and networks," said Park. "The distinguishing attributes of these networks raise new security implications that have not been studied in a systematic way by the research community."
The network attributes that Park’s research group will investigate include:
- cooperative spectrum sensing, which occurs when multiple cognitive radio devices work together to identify vacant radio spectrum bands;
- on-demand spectrum contention, or protocols that enable multiple devices to work together with minimum interference and efficient sharing of the radio spectrum;
- and spectrum etiquette mechanisms, which can prevent the malicious use of cognitive radio devices to violate or bypass spectrum policies.
Every CAREER project has an educational component. Park will develop both undergraduate and graduate courses in cognitive radio systems at Virginia Tech. He also plans to initiate a summer internship program for women undergraduates and to disseminate his course materials to educational institutions in Virginia that serve underrepresented students.
Park joined the Virginia Tech faculty in 2003 after receiving his Ph.D. from Purdue University’s School of Electrical and Computer Engineering. He earned his master’s and bachelor’s degrees in electronic engineering from Yonsei University in Seoul, South Korea. He is the director of the Laboratory for Advanced Research in Information Assurance and Security (ARIAS), which is associated with Wireless @ Virginia Tech.