OFDMA Based UAVs Communication for Ensuring QoS

Abstract

Unmanned aerial vehicles (UAV), more often familiar as drone, has been widely used both in civilian activities and military missions. UAV ad-hoc networks, also known as flying ad-hoc networks, are ad-hoc multi-UAV systems (FANETs). The FANET’s medium access control (MAC) and physical (PHY) layer specifications are defined by the IEEE 802.11 standard, which uses the enhanced distributed channel access function (EDCAF) to assure the quality of service (QoS) in the MAC layer. Because it suffers from collisions, carrier sensing multiple access with collision avoidance (CSMA/CA) is useless when a high data rate is required. As a result, the use of orthogonal frequency division multiple access (OFDMA) is advised. By lowering the collision probability, OFDMA increases performance and reduces latency. This study develops an analytical model for assessing IEEE 802.11 EDCAF performance for OFDMA-based UAV communication. A new channel contention method that combines EDCAF and OFDMA is suggested. Firstly, EDCA based prioritized channel contention is done. Then, channel access and transmission are done using OFDMA. We undertake a theoretical study based on the Markov chain model, which gives throughput, packet drop rate (PDR), and delay expressions. The simulation results verify the model performance and show that the proposed technique ensures strict delay requirements and supports QoS.