Abstract:
The increasing demand of usable spectrum range alarmed the world of serious shortage in the coming years. Cognitive Radio technology emerged to solve this problem by allowing unlicensed users to utilize the spectrum resources whenever the licensed users are not active. With the emergence of this technology many security issues arose, that if successful may hamper all the benefits this promising technology has to offer. Among many other security issues Primary User Emulation Attack (PUEA) is one. In this thesis focus is on the PUEA however other attacks to Cognitive Radio are also discussed. Existing work to counter PUEA is also discussed, along with its limitations.
The thesis basically describes the proposed approach based on randomized sensing to counter PUEA. It is proposed to have sensing randomized at different intervals other than the defined sensing intervals. This approach is advantageous over other approaches in a sense that it does not only identify a malicious PUEA but also provides countermeasure, as the unlicensed user (also known as Secondary User or SU) is able to utilize remaining slot for performing its transmission.
To check the impact of PUEA on the Cognitive Radio technology, an environment consisting of nodes (CRs) was setup. To generate effective results, environment close to the real world (in terms of behavioral aspects of the nodes in Cognitive Radio) was simulated. The behavior of nodes in attack free environment was evaluated first and then the effects of PUEA were evaluated through simulation results. In the end the results after incorporating the proposed approach were generated to see the impact of proposed approach on attack environment.
