| Abbreviation | Definition |
|---|---|
| AOS | Alternate Operator Service |
| AP | Access Point |
| AP | Action Point |
| APCO | Association of Public Safety Communications Officials |
| APDU | Application Protocol Data Unit |
| APM | Attached Pressurized Module |
| APN | Access Point Name |
| APOT | Access Point Of Termination |
| APR | Alarm Processing Remote |
| APS | Affordable Portable Services |
| APS | Automatic Protection Switching |
| APTC | Atlantic Provinces Telecommunications Council |
| APTG | Academy for Professional TraininG |
| APTG | Amplifier Probe and Tone Generator Kit |
| APTG | Asia Pacific Telecom Group |
| APTI | Alaska Public Telecommunications, Inc |
| ARA | Apple Remote Access |
| ARAI | Adjunct Route Application Interface |
| ARD | Automatic Ring Down |
| ARP | Access Responsible Party |