The Cognitive Radio Network

Broadly speaking, the word cognition means “the act of knowing or knowledge which relates to different thought processes and actions and how the outcome of these processes affects other groups which work in close relation.” Cognition is closely related to concepts of mind such as perceiving, learning, reasoning, and intelligence. We generally associate the word cognition with cognitive science, the study of mind and intelligence. As the title suggests, cognitive radio is the future of communications with added artificial intelligence on its communication backbone. With an increasing number of devices becoming wireless, the finite radio spectrum is becoming more and more occupied and problems of traffic congestion and interference are becoming frequent. Cognitive Radio Network seems to offer a solution to these problems. Well, now how can a radio network system become intelligent? Isn’t it intelligent enough? How will concepts like cognitive radio help in improving our existing wireless communication network? How will future gadgets evolve based on the concepts of cognitive radio? How will a cognitive engine change the face of our wireless systems? Perhaps more than once, we all have faced situations when our mobile calls get blocked because of the unavailability of free radio circuits or when the quality of the service on our radio systems goes real low while listening to commentary on a soccer match. All these situations are common when in a given region, more users than a network can handle happen to use the frequency spectrum all at the same time. Since our existing radio networks are trained to route calls or provide radio reception depending upon the free circuits available, they lack the intelligence to switch the transmission from the crowded part of the spectrum to a more open and less occupied region. Our wireless networks lack decision making capability. They are not aware of the environment and they lack frequency spectrum sensing capabilities. They are not intelligent enough. This is where the concept of cognitive radio comes into picture. The term cognitive radio is coined by Joseph Mitola III. According to him, Cognitive radio is “a smart radio that would be self-aware, RF-aware, user-aware, and would include language technology and machine vision, along with a lot of high-fidelity knowledge of the radio environment.” It is based on the combined concepts of software-defined radio and artificial intelligence. The cognitive radio concept enables a network or wireless node to change its transmission or reception parameters to communicate efficiently by avoiding interference with other users. With this technology, the cognitive radio actively monitors the external wireless network environment that affects the propagation of radio signals, user behavior, the network states and internal factors such as system hardware, sensors, etc. Based on the results gathered, the cognitive engine asks the system to alter the transmission and reception parameters. The cognitive engine is the decision making module where the intelligence of the system resides, which makes the cognitive radio concept dynamic. Cognitive Radio will prevent traffic jams in wireless networks by routing transmissions of signals from occupied frequency bands to idle frequency bands.