As power consumption results in greenhouse gas emissions and energy costs for operators, analyzing power consumption in wireless networks and portable devices is of crutial importance. Due to environmental effects resulted from energy generation and exploitation as well as the cost of surging energy, energy-aware wireless systems attract unprecedented attention. Cognitive Radio (CR) is one of the optimal solutions that allows for energy savings on both the networks and devices. Thus, cognitive radio contributes to increase spectral and energy efficiency as well as reduction in power consumption. In addition, energy consumption of the CR technologies as intelligent technology should be considered to realize the green networks objective. In this article, we look into energy efficiency of the cognitive wireless network paradigms. Moreover, energy efficiency analysis and modelling in these systems are specifically focused on achieving green communications objectives. However, CRs by altering all elements of wireless data communications are considered in this paper, and the energy-efficient operation and energy efficiency enabler perspectives of CRs are also analyzed.

由于功耗会导致运营商排放温室气体和能源成本，因此分析无线网络和便携式设备中的功耗至关重要。由于能源的产生和开发所带来的环境影响以及能源激增的成本，节能型无线系统引起了空前的关注。认知无线电（CR）是可在网络和设备上实现节能的最佳解决方案之一。因此，认知无线电有助于提高频谱和能量效率以及降低功耗。此外，应考虑将CR技术作为智能技术的能耗，以实现绿色网络的目标。在本文中，我们研究了认知无线网络范例的能效。此外，这些系统中的能效分析和建模专门针对实现绿色通信目标。但是，本文考虑了通过更改无线数据通信的所有元素来实现CR的方法，并且还分析了CR的节能操作和能效促成因素。