Random Access Method for LEO Satellite Internet Based on Adaptive ACB Mechanism

In the initial random access phase of Low Earth Orbit Satellite Internet (LEO SI), the complex handshake process for network connection establishment between user terminals and LEO satellites faces challenges. Traditional random access methods are suitable for a limited number of user terminals but may cause severe access congestion and depressed connection success probability when handling massive intermittent access requests. To address this issue, this paper proposes an adaptive Access Class Barring (ACB) mechanism-based random access method. Considering the 3GPP’s ACB method, the high dynamics of LEO SI, and resource constraints, this mechanism dynamically selects the optimal ACB factor by analyzing the number of successfully accessed terminals in each time slot, thereby balancing access efficiency and resource utilization. Simulation results show that for the case with 600 devices, the adaptive ACB method improves access success rates by approximately 45.4% (M0 = 50) and 48.6% (M0 = 60) compared to traditional static ACB strategies, demonstrating its effectiveness in enhancing network performance in high-density scenarios.