The objective of this review paper is to discuss the various channel access methodologies applied in various sensor and actuation based wireless networks. In most of Wireless Sensor Networks (WSNs) researchers have focused on priority centered approaches for channel accessibility. This paper also explains the procedure for Medium Access Control (MAC) in Cyber Physical Systems (CPSs) which is a combination of Wireless Sensor Actuator Networks (WSANs) and WSNs. Finally, we discuss the successive collision avoidance technique using the IEEE 802.11 MAC protocol, and also brief on how the Internet of Thing (IoT) approach connects and transfers information among smart devices linked in a wireless network. © 2017, Walailak University. All rights reserved.