🤖 AI Summary
To address connection management challenges in 6G integrated space-air-ground vehicular networks—arising from dynamic topologies and partial observability—this paper proposes a multi-agent collaborative decision-making framework. Methodologically, it integrates multi-head self-attention to enhance robust state estimation under partial observability; employs self-imitation learning to accelerate policy convergence; and leverages channel fingerprinting for low-overhead, high-accuracy link-state awareness. The framework enables autonomous, joint optimization of handovers across heterogeneous V2S, V2I, and V2V links. Evaluated via SUMO-based simulations compliant with 3GPP standards, the approach achieves up to a 14% improvement in transmission utility while maintaining over 92% state estimation accuracy across varying vehicle densities and levels of inter-agent information sharing. These results demonstrate significant gains in real-time responsiveness and environmental adaptability within highly dynamic network conditions.
📝 Abstract
Managing connectivity in integrated satellite-terrestrial vehicular networks is critical for 6G, yet is challenged by dynamic conditions and partial observability. This letter introduces the Multi-Agent Actor-Critic with Satellite-Aided Multi-head self-attention (MAAC-SAM), a novel multi-agent reinforcement learning framework that enables vehicles to autonomously manage connectivity across Vehicle-to-Satellite (V2S), Vehicle-to-Infrastructure (V2I), and Vehicle-to-Vehicle (V2V) links. Our key innovation is the integration of a multi-head attention mechanism, which allows for robust state estimation even with fluctuating and limited information sharing among vehicles. The framework further leverages self-imitation learning (SIL) and fingerprinting to improve learning efficiency and real-time decisions. Simulation results, based on realistic SUMO traffic models and 3GPP-compliant configurations, demonstrate that MAAC-SAM outperforms state-of-the-art terrestrial and satellite-assisted baselines by up to 14% in transmission utility and maintains high estimation accuracy across varying vehicle densities and sharing levels.