GPSR-RA: A Cross-Layer Position-Based Routing Protocol with Dynamic Bitrate Adaptation for FANETs

Abstract

. In FANETs, the rapid fluctuations in link quality, caused by continuous changes in UAV distances, interference, environmental conditions, transmission power, and multipath effects, significantly impact data transmission efficiency. This paper proposes the GPSR-RA protocol. This paper proposes the GPSR-RA (GPSR with BitRate Adaptation) ), an enhancement of the GPSR protocol, designed to adjust the bitrate during data transmission based on link quality. GPSR-RA dynamically adjusts the bitrate by utilizing the SNIR (Signal-to-Noise-plus-Interference Ratio) parameter to select an optimal bitrate, thereby improving packet delivery ratio, reducing latency, and maximizing bandwidth utilization. GPSR-RA retains the routing mechanism of GPSR but incorporates a dynamic bitrate adjustment mechanism based on SNIR and the adjustment thresholds for increasing or decreasing at each bitrate. GPSR-RA collects SNIR information from the physical layer via Hello packets and stores it in the neighbor table. The SNIR is then passed this information to the MAC layer immediately after the next-hop node is determined. The bitrate adjustment module (MACSnir-RA) in GPSR-RA actively increases or decreases the bitrate according to the SNIR value, enabling the system to respond promptly to changes in the link quality, and thus improve network performance. Simulation results on the OMNeT++ platform demonstrate that GPSR-RA significantly enhances packet delivery ratio, increases network throughput, and reduces end to end delay compared to GPSR.