G G.807 Galileo Geneva-06 GERAN GGSN G.hn Giga Gigabit Ethernet Gigabit Wi-Fi GLONASS GMDSS GMES GMPLS GMRS GMSC GNSS GoTa GPRS GPS GSM GSM1800 GSM1900 GSM 1X GSM900 GSMA GSM-P GSM Parking GSM-R GSM-T GT800 Guard band