Semi-persistent CSMA/CA for efficient and reliable communication in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are constituted by small, intelligent, and resource-constrained wireless devices (or sensor nodes) that are densely deployed in a certain field to monitor a specific phenomenon. The sensor nodes are constrained in power resources as well as memory and processing capabilities. This fact imposes an essential requirement on the design of WSNs; all algorithms and protocols should be lightweight and conservative in their power consumption. In this paper we aim at researching the opportunity of building a hybrid MAC protocol for beacon-enabled 802.15.4-based WSNs that incorporates some aspects of 802.11 MAC into the operation of 802.15.4 MAC. We will study the impact of increasing the number of Clear Channel Assessments (CCAs) on the performance, and control this increase adaptively to better enhance the efficiency of the network. The main goal is to design a MAC protocol that can respond to the changes in the network (in terms of the size of the network, the intensity of the traffic, or the urgency of the traffic).