| Abbreviation | Definition |
|---|---|
| AIU | Analog Interface Unit |
| ALB | Analog LoopBack |
| ALC | Automatic Line Controller |
| ALCAP | Access Link Control Application Protocol |
| ALI | Automatic Location Identifier |
| ALIS | Access Lines In Service |
| ALIT | Automatic Line Insulation Test |
| ALOC | Average Length Of Call |
| ALS | Accounts Ledger System |
| ALS | Alternative Line Service |
| AM | Advance Mobile |
| AM | Appliction Manager |
| AMA | Automatic Message Accounting |
| AMBPU | Average MB Per User |
| AMC | Adds, Moves, and Changes |
| AMI | Advanced Metering Infrastructure |
| AMI | Alternate Mark Indicator |
| AMI | Alternate Mark Inversion |
| AML | Amplitude Modulated Link |
| AMOLED | Active Matrix Organic Light-Emitting Diode |