  At present, lots of works focus on spectrum allocation of wireless networks.
In this paper, we proposed a Cognitive based spectrum access by
opportunistically approach of Heterogeneous Wireless networks based on Fuzzy
Logic system. The Cognitive Radio is a technology where a network or a wireless
system changes its environment parameters to communicate efficiently by
avoiding the interference with the users. By applying FLS (Fuzzy Logic System),
the available spectrum utilization is effectively utilized with the help of the
three antecedents namely Spectrum utilization efficiency, Degree of mobility,
Distance from primary user to the secondary users. The proposed work is
compared with normal Spectrum Utilization method. Finally, Simulation results
of the proposed work Fuzzy Logic System shows more efficient than the normal
Spectrum utilization method.
