Cognitive Radio Networks (CRNs) represent a cutting-edge solution to the
growing problem of limited available spectrum. With the increasing
demand for wireless communication services, the efficient utilization of
spectrum resources becomes paramount. Green CRNs offer a dynamic and
opportunistic approach by intelligently sensing and accessing idle
licensed spectrum, known as white spaces focusing on environmentally
conscious communication methods. These unoccupied frequency bands, left
unused by primary users (PUs), present an opportunity for CRNs to
enhance spectrum utilization and alleviate the spectrum scarcity
challenge. In the presented study, we concentrate on energy conservation
in “Green” CRNs, with a specific focus on base stations (BSs). We
suggest an energy-efficient approach that utilizes multiple sleep modes
employing an N-policy, with the objective of addressing the growing need
for environmentally friendly communication practices. To model the
energy-saving process and assess system performance, we employ a
semi-Markov process (SMP). Moreover, the paper provides a detailed
analysis of performance metrics, encompassing average latency for
Secondary Users (SUs), throughput of the system, energy saving factor,
and energy consumption.