The high demand for wireless sensor networks (WSNs) is growing in
different applications. Most WSNs use the unlicensed band (ISM band) which
leads to congestion in that band. On the other hand, without damaging the
quality of service (QoS) of the network, minimizing the consumed energy is
vital in sensor networks design. Cognitive radio-based wireless sensor networks
(CRWSNs) afford some solutions to the problem of scarce unlicensed band
spectrum. The spectrum sensing is the main function of the cognitive radio
networks. In this paper, for maximizing the accuracy of sensing, as well as the
energy efficiency of the network, proposed novel method by employing adaptive
spectrum sensing. Spectrum sensing is performed by Secondary User (SU) to
identify if the Primary User (PU) is idle, then for verifying that primary user is
actually idle, sensing the spectrum again is done by secondary user in order to
provide better protection for the primary user. Because of CRWSN has a constraint in energy, that adaptive interval of sensing could also, be modified to
optimize the energy efficiency of the network according to the different activity
of the PU. Simulation results were provided to validate the efficacy of the
proposed algorithms to enhance both spectrum sensing performance and energy
efficiency