Sensing, computing and communication are the main features of a wireless sensor network (WSN) which serves a wide range of applications. Despite its versatility and simplicity, it brought up various challenges such as limited storage, power consumption from radio activities, just to mention a few. The distinguishing traits of sensor networks have a direct impact on their protocol design at each layer, especially at the Medium Access Control (MAC) layer since it manages transmission scheduling as well as duty cycling for energy conservation. To maximize energy efficiency of WSNs, a critical analysis of the radio duty cycle of the WSN operating systems were carried out with experimental evaluation. Moreover, we focus on the energy consumption by conducting experimental measurements on different platforms i.e. OpenMote-CC2538 on various operating systems. Results shows that IEEE 802.15.4e Time Synchronized Channel Hopping (TSCH) has great impact on the energy consumption with respect to other radio duty cycles.