Power control and channel allocation mechanism for coexistence between secondary cognitive networks

With the growth of wireless service demand and the inefficiency in spectrum use, cognitive networks rise as a technology that improves spectral efficiency by allocating in an opportunistic fashion access to licensed frequency bands. This paper presents a dynamic mechanism for channel allocation and power control jointly applied to cognitive networks regarding the dynamic use of channels in the public safety frequency bands. With the need to quickly vacate a channel in the presence of primary user, an important issue to be addressed is the cost of channels relocation. The proposed mechanism takes into account the history of channels allocation, reducing the channel migration impact on users, while considering the reduction in interference among cognitive users. The proposed algorithm can reduce up to 54% the number of client reassociations compared to an algorithm that does not consider it. In more dense scenarios, can also reduces the total interference.