| Abbreviation | Definition |
|---|---|
| ETT | Emerging Telecommunications Technologies |
| ETT | Emona Telecoms Trainer |
| EUCL | End User Common Line |
| EUS | End User Segment |
| EVA | Electronic Video Agent |
| EVC | Electronic Voucher Charging |
| EVN | Enterprise VoIP (Voice-over-IP) Network |
| EVRC | Enhanced Variable Rate CODEC (CODer-DECoder) |
| F | Frequency |
| FA | Failed Answer |
| FAC | Forced Authorization Code |
| FACS | Facility Assignment and Control System |
| FANTASTIC-5G | Flexible Air iNTerfAce for Scalable service delivery wiThin wIreless Communication networks of the 5th Generation |
| FAS | Fals ansewring supervision |
| FAS | Frame Alignment Signal |
| FAST | Field Automated Subscriber Testing |
| FAW | Frame Alignment Word |
| FB | Framing Bit |
| FCA | Fixed Channel Assignment |
| FCAL | Fiber Channel Arbitrated Loop |