Dec 10, 2025 — On Dec 19, 2018, the Guigang radio management office (Guangxi) received a letter from the Nanning Telecom Division of China Railway Nanning Bureau, reporting that schools in Guigang used mobile-phone jammers during high-school exams, severely disrupting GSM-R railway communications. The case was investigated and resolved.
Source: zhangqiaokeyan.com