Performance Analysis of Slotted CSMA/CA in UAV-Based Data Collection Network

Recently, unmanned aerial vehicle (UAV) assisting data collection in wireless sensor network (WSN) has attracted increasingly wide attentions. This paper focuses on the analytical model to evaluate and optimize the performance of slotted CSMA/CA in UAV-based WSNs considering the continuous mobility of UAV. Contrary to the traditional WSNs, the number of active nodes covered by UAV is variable due to both the mobility of UAV and the discontinuous packet arriving at sensor nodes. In addition, the Doppler shift will also degrade the network throughput performance. Firstly, we innovatively formulate a group of recursion equations and propose an algorithm to obtain the sequence of covered node number varying with time. Then, an expected throughput considering both the channel contention in MAC layer and the bit error rate in physical layer is defined to evaluate the network performance. Numerical analyses show the significant influences on the network performance made by the cycle of beacon frame, the flying speed of UAV, the density of nodes and the number of packets.