Cross-Layer Optimized OLSR Protocol for FANETs in Interference-Intensive Environments

Highlights: What are the main findings? A cross-layer optimized OLSR protocol (OLSR-LCN) integrates link lifetime, interference index, and node load for adaptive MPR selection and routing. Extended HELLO and TC messages enable cross-layer information exchange, reducing end-to-end delay and packet loss while improving network efficiency. What are the implications of the main findings? Enhances UAV network reliability and scalability in highly dynamic and interference-prone environments. Provides a practical and implementable routing solution for stable FANET communication under complex electromagnetic conditions. The conventional OLSR protocol faces substantial challenges in highly dynamic and interference-intensive UAV environments, including high mobility, frequent topology changes, and insufficient adaptability to electromagnetic interference. This paper proposes a cross-layer improved OLSR protocol, OLSR-LCN, that integrates three evaluation metrics—link lifetime (LL), channel interference index (CII), and node load (NL)—to enhance communication stability and network performance. The proposed protocol extends the OLSR control message structure and employs enhanced MPR selection and routing path computation algorithms. LL prediction enables proactive selection of stable communication paths, while the CII helps avoid heavily interfered nodes during MPR selection. Additionally, the NL metric facilitates load balancing and prevents premature node failure due to resource exhaustion. Simulation results demonstrate that across different UAV flight speeds and network scales, OLSR-LCN protocol consistently outperforms both the OLSR and the position-based OLSR in terms of end-to-end delay, packet loss rate, and network efficiency. The cross-layer optimization approach effectively addresses frequent link disruptions, interference, and load imbalance in dynamic environments, providing a robust solution for reliable communication in complex FANETs.