| Abbreviation | Definition |
|---|---|
| FCC | Federal Communications Commission |
| FCFS | First-Come, First-Served |
| FCM | Flow Control Manager |
| FCO | Flexible Compute Orange |
| FCO | Foreign Central Office |
| FCT | Fixed Cellular Terminal |
| FCV | Free Call Value |
| FD | Full Duplex |
| FDD | Fast Direct and Dedicated |
| FDD | Frequency Division Duplex |
| FDI | Feeder Distribution Interface |
| FDL | Facility Data Link |
| FDM | Frequency Division Multiplexing |
| FDOA | Frequency Difference Of Arrival |
| FDS | Filtering, Distributing, and Serving |
| FDTD | Finite-Difference Time-Domain |
| FE | Far End |
| FEAC | Far End Alarm and Control |
| FEBE | Far End Block Error |
| FEBE-F | Far End Block Error count - Fast data |