With today's cell phone, the user's access is limited to the provider's network. Mitre computer scientist Joseph Mitola, currently working with both the National Security Agency and Defense Advanced Research Projects Agency (DARPA), thinks he has a system that will change that. He calls it "cognitive radio" and says his system will give wireless devices machine-learning capabilities. Mitola talked to CTO Media Senior Editor Loretta W. Prencipe about how his vision of "cognitive radio" would work, and how it could redefine cell phone technology.
IW: You coined the term cognitive radio. What is it?
JM: A cognitive radio (CR) has a computation model of itself. It knows that it is a smart radio, and it has a user who does certain things. If you're a journalist, you might be willing to pay a premium to get higher speech quality. If a CR detected an interview, and it would cost three cents a minute for a clearer signal, [a message] would pop up on the display asking if you want to pay three cents more a minute for clearer audio. Over time, it would learn and would build into the computation model that the user likes high-quality speech when doing interviews. This computation model of itself, of the user and the network, plus the machine learning means that the user doesn't have to reprogram it and keep telling it what to do. ... There isn't a true working model yet. It may be five to 10 years out.
IW: Define the architecture of a CR.
JM: It's a software radio. This would have enough flexibility in the hardware to be programmed to a band or mode. So instead of being stuck in the 800 to 900MHz band, it would be able to adapt over to an ISM band or up to an IEEE band or 5GHz. The CR would know what to do based on experience. It knows where home is. You get in the car to go to work. It's measuring the radio propagation, signal strength, the quality of the different bands as it drives around with you. It's building this nifty internal database of what it can do when and where.
IW: Could CR lead to convergence of wireless devices?
JM: Certainly. It would enhance convergence by simplifying the user's interaction with the increasingly complex devices. The vision of CR is that your PDA, laptop, and automobile would employ the mix of Bluetooth, IEEE 802.11, and cellular standards from 1G to 3G as needed by the user.
IW: What are the technical challenges?
JM: Affordability of the services. Right now there is a lot of pressure on service providers for profitability for [a] third generation of wireless. The big winners made a lot of money and captured the lead in [the] second generation. No one is making money in 3G. It costs a lot to deploy. The killer app has been slow to appear.
IW: What does a cognitive radio cell phone look like?
JM: In order for a CR to know things that are important, to deliver this level of service, it's got to have a lot more sensors on it than today's radio. For a CR to know that it just fell on the floor, to send a page to the user's Blackberry when it falls on the floor, it needs an accelerometer, a motion detector. A CR would wait a reasonable amount of time and then send a little page to my Blackberry saying, "Hey, you just dropped me. I'm back at the coffee table." [Because] GPS doesn't work well in buildings or urban settings, it would also need more sophisticated built-in sensors.
IW: CR would find the quickest and best spectrum to send video, to pick up audio?