Scalable OFDMA-Based Multi-User Channel Access for FANETs in Disaster Scenarios

Abstract

Flying Ad Hoc Networks (FANETs), with its high mobility and dynamic topology, enables wireless communication between unmanned aerial vehicles (UAVs); this makes efficient channel access a major challenge. However, traditional singleuser and conventional contention-based medium access control (MAC) protocol suffer from extreme control overhead and unsuccessful backoff adaptation, which leads to high access delay and spoiled network performance under dense UAV deployments. Regarding these issues, this paper proposes an orthogonal frequency division multiple access (OFDMA)-based MAC protocol that jointly integrates multi-user request-to-send/clear-to-send (MU-RTS/CTS) signaling and an backoff mechanism with joint channel sensing. By authorizing aligned transmission on multiple frequency resource units and restricting excess contention and backoff expansion, the proposed model notably reduces control overhead while improving channel utilization and synchronization among UAVs. A transmission Opportunitybased analytical model is evolved to assess system throughput and delay under increasing network density and large-scale simulations are administered for authentication of performance. Simulation results show that the crucial upgrades throughput and reduces access delay compared to traditional FANET channel access, especially in dense UAV scenarios.