Investigation of Underground Communication Quality Using Distributed Antenna Systems Considering Radio-Frequency Signal Propagation Characteristics in Almaty Metro Tunnels. - Askar Abdykadyrov; Moldir Kuatova; Nurzhigit Smailov; Zhandos Dosbayev; Sunggat Marxuly; Maxat Mamadiyarov; Ainur Kuttybayeva; Nurlan Kystaubayev; Amirkhan Bekmurza (Network, 2026)