Original: Telecommunication network accessibility A full GSM ( GSM-900 and GSM-1800 ) , CDMA and TDMA mobile phone network is in place through out the MTR system of stations and tunnels allowing passengers to stay connected underground .
Simplified: Telecommunications network coverage A full GSM ( GSM-900 and GSM-1800 ) , CDMA and TDMA mobile phone network is in place through out the MTR system of stations and tunnels .