Design and performance verification of an emergency communication system for deep-buried long-distance urban rail transit tunnels under extreme disasters
Yi Zheng, Xuecheng Zou · 2025
This paper addresses the critical issue of emergency communication failure in deep-buried, long-distance urban rail transit tunnels, often caused by vulnerable communication facilities and public network paralysis during extreme disasters (e.g., earthquakes, fires). We propose a hierarchical, heterogeneous, and converged emergency communication system. This innovative system integrates MIMO Mesh broadband ad-hoc networking, 5G MIMO/3GPP-LTE protocol stacks, and Software-Defined Radio (SDR) reconfigurable architecture. Through synergistic optimization of Orthogonal Frequency Division Multiplexing (OFDM), Space-Time Block Coding (STBC), and Dynamic Spectrum Access (DSA) technologies, it achieves beyond-line-of-sight communication and high-bandwidth transmission even under extreme conditions. Field tests in the Shanghai Metro Chongming Line tunnel (40m buried depth, 7.3km length) demonstrated four core advantages in harsh environments characterized by a shielding factor >35dB and a multipath delay spread of 1.5μs: (1) Strong Penetration: Single-hop coverage distance reached 3.2km (path loss 110dB), a 120% improvement over traditional LTE solutions; (2) High Survivability: The network maintained a survival rate >98.6% with 30% node damage; (3) Multi-Service Guarantee: It supported 64 concurrent node accesses with a 99.3% QoS guarantee rate for mixed services (video 15Mbps, voice 64kbps, sensing 10kbps); (4) Intelligent Anti-Interference: Reinforcement learning (DQN algorithm)-based dynamic spectrum allocation achieved a 93.7% effective communication duration ratio under -80dBm interference. Our research indicates that this system can provide stable and reliable spatio-temporal-frequency integrated communication services in complex environments marked by severe signal shielding, significant multipath fading, and strong electromagnetic interference. It offers an innovative technical solution and empirical support for emergency communication needs in underground "lifeline" projects during extreme disasters.