Cognitive Wireless Sensor Networks is an emerging technology with great potential to avoid traditional wireless problems such as reliability, interferences and spectrum scarcity. Because of the Wireless Sensor Network fast growth and the use of batteries, current rate of power consumption per unit of data cannot be sustained. Therefore, one of the major challenges face today is low power consumption in Wireless Sensor Networks. Cognitive Wireless Sensor Networks framework is a key issue in green communications because of many protocols, strategies and optimization algorithms could be tested. In this paper a framework composed of a network simulator with cognitive capabilities and low power Cognitive Wireless Sensor Networks real devices with a feedback relation is presented.