| G/T |
Ratio of gain to noise temperature |
| GBS |
Geographical Band Segmentation |
| GEMS |
Global Environment Monitoring Systems |
| GEO |
Geostationary Orbit (satellite) |
| GES |
Ground Earth Station |
| GFSK |
Gaussian Frequency-Shift Keying |
| GLONASS |
GLobal NAvigation Satellite System (Russia) |
| GMDSS |
Global Maritime Distress and Safety System |
| GMPCS |
Global Mobile Personal Communication by Satellite |
| GMSK |
Gaussian-filtered Minimum-Shift Keying |
| GNSS |
Global Navigation Satellite System |
| GOES |
Geostationary Operational Environmental Satellite |
| GPS |
Global Positioning System (USA) |
| GRGS |
Groupe de Recherches de Géodesie Spatiale (F) |
| GSM |
Global System for Mobile Communications |
| GSM-900 |
Groupe Spécial Mobiles (European GSM) |
| GSM-R |
Global System for Mobile Communications on Railways |
| GSO |
Geostationary Satellite Orbit |
| GVLS |
Global Verification and Location System |
Committee on Radio Astronomy Frequencies