Degrees of Cooperation in Dynamic Spectrum Access for Distributed Cognitive Radios
The Federal Radio Act under Federal Communications Commission (FCC) allows predetermined users the right to transmit at a given frequency. Non-licensed users are regarded as “harmful interference” and not allowed to transmit in a certain frequency bands. As the demands for wireless communication become more and more pervasive, the wireless devices must find a way for the right to transmit at frequencies in the extremely limited radio band. However, there exist a large number of frequency bands that have considerable, and sometimes periodic, dormant time intervals. In the literature, those frequency bands refer to spectrum holes [1,2]. So there is a dilemma that on one hand the mobile users have no spectrum to transmit, while on the other hand some spectrums are not fully utilized.
Han, Zhu. (2007). "Degrees of Cooperation in Dynamic Spectrum Access for Distributed Cognitive Radios". Cognitive Wireless Communication Networks, . http://dx.doi.org/10.1007/978-0-387-68832-9