Intelligent Systems for Beyond‐Line‐of‐Sight Defense Communication: Technologies, Case Studies, and Research Frontiers

Beyond‐line‐of‐sight (BLOS) communication is a fundamental component of modern defense strategies, enabling secure and reliable information exchange in environments where traditional line‐of‐sight (LOS) methodologies are ineffective due to obstructions or operational constraints. This article explores the key technologies advancing BLOS communication, with a focus on nanonetworks, aerial relays, and satellite‐based defense communication. To underscore the real‐world applications and challenges of BLOS systems, we present two practical case studies, one examining tropospheric ducting for BLOS maritime communication, highlighting its advantages and implementation challenges, and another on UAV path planning in radar‐threat war zones, demonstrating the role of optimization techniques in enhancing operational efficiency. Furthermore, this study identifies several critical future research directions in BLOS defense communication, including resilience enhancement, heterogeneous network integration, contested spectrum management, advancements in multimedia communication, adaptive methodologies, and the expanding domain of the Internet of Military Things (IoMT). Addressing both technological advancements and real‐world constraints, this research lays a foundation for strengthening BLOS communication systems, fostering cross‐sector collaboration, and driving innovation at the intersection of defense, academia, and industry.