Input (grade 13): 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.
Output (grade 7): 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. Passengers can stay connected underground.