| AA |
Accounting Authority |
| AAIC |
Accounting Authority Identification Code |
| AAL |
ATM Adaptation |
| AA/TDMA |
Adaptive Assignment TDMA |
| ABE |
Alternative Billing Entity |
| ABM |
Apogee Boost Motor |
| ABM |
Asynchronous Balanced Mode |
| ABR |
Audio Broadcast Receiver |
| ABR |
Available Bit Rate |
| ABU |
Asian Broadcasting Union |
| AC |
Alternating Current |
| AC |
Assignment Channel |
| ACAST |
Advisory Committee on the Application of Science and Technology to Development |
| ACC |
Antenna Control Console |
| ACC |
Automatic Chroma Correction |
| ACD |
Automatic Call Distribution |
| ACE |
Audio Connecting Equipment |
| AceS |
Asia Cellular System |
| ACI |
Adjacent Channel Interference |
| ACK |
Acknowledgement |
| ACM |
Adaptive Coding and Modulation |
| ACME |
Analogue Circuit Multiplication Equipment |
| ACP |
Adjacent Channel Power |
| ACPR |
Adjacent Channel Power Ratio |
| ACPR |
Adjacent Channel Protection Ratio |
| ACPW |
Asymmetrical Coplanar Waveguide |
| ACS |
Access Control System |
| ACS |
Attitude Control System |
| ACTP |
Abridged Condensed Time Plan |
| ACTS |
Advanced Communication Technology Satellite |
| ACU |
Antenna Control Unit |
| A/D |
Analogue to Digital |
| ADACS |
Attitude Determination and Control System |
| ADC |
Analogue to Digital Conversion |
| ADCE |
Attitude Determination and Control Electronics |
| ADCS |
Attitude Determination and Control System |
| ADD |
Architectureal Design Document |
| ADDT |
Advanced Digital Television Technologies |
| ADE |
Above Deck Equipment |
| ADM |
Adaptive Delta Modulation |
| ADN |
Advanced Digital Network |
| ADP |
Acceptance Design Package |
| ADPCM |
Adaptive Differential Pulse Code Modulation |
| ADR |
Architectural Design Review |
| ADR |
Astra Digital Radio |
| ADS-B |
Automatic Dependent Surveillance Broadcast |
| ADSL |
Asynchronous Digital Subscriber Line |
| AES |
Aircraft Earth Station |
| AF |
Audio Frequency |
| AFC |
Automatic Frequency Control |
| AFETR |
Air Force Eastern Test Ranges |
| AFSS |
Automated Flight Safety System |
| AGC |
Automatic Gain Control |
| AGN |
Active Galactic Nucleus |
| A-H |
Ampere Hour |
| A-H |
Amp-House |
| AIAA |
American Institute of Aeronautics and Astronautics |
| AIS |
Alarm Indication Signal |
| AIT |
Assembly, Integration and Test |
| AIV |
Assembly, Integration and Verification |
| AKM |
Apogee Kick Motor |
| ALS |
Automatic Landing Sequence |
| ALT |
Altitude |
| AM |
Additive Manufacturing |
| AM |
Amplitude Modulation |
| AM |
Apogee Motor |
| A-MAC |
Type A Multiplexed Analogue Components |
| AMF |
Apogee Motor Firing |
| AMPS |
Advanced Mobile Phone System |
| AMS |
Attitude Measurements Sensor |
| AMSS |
Aeronautical Mobile Satellite Service |
| ANC |
Automatic Nutation Control |
| ANSI |
American National Standards Institute |
| AO |
Adaptive Optics |
| AoA |
Angle of Attack |
| AOC |
Advanced Operations Centre |
| AOCS |
Attitude and Orbit Control System |
| AoD |
Audio on Demand |
| AoE |
Area of Effect |
| AOR |
Atlantic Ocean Region |
| AOS |
Acquisition Of Signal |
| AOTS |
Advanced Orbital Test Satellite |
| APC |
Adaptive Predictive Coding |
| APC |
Autonomous Payload Controller |
| APCS |
Autonomous Payload Control System |
| APD |
Avalanche Photodiode Detector |
| APE |
Antenna Positioning Electronics |
| APE |
Attitude Processor Electronics |
| APID |
Application Process IDentifier |
| APM |
Amplitude Phase Modulation |
| APM |
Antenna Positioning Mechanism |
| APS |
Auxiliary Power Supply |
| APSK |
Amplitude Phase Shift Keying |
| AR |
Area Ratio |
| AR |
Axial Ratio |
| ARA |
Angular Rate Assembly |
| ARC |
Administrative Radio Conference |
| ARF |
Alternate Recovery Facility |
| ARINC |
Aeronautical Radio Inc |
| ARP |
Address Resolution Protocol |
| ARPA |
Advanced Research Projects Agency |
| ARQ |
Automatic Repeat reQuest |
| ARTI |
Arab Regional Telecommunications Institute |
| ASA |
American Standards Association |
| ASBU |
Arab States Broadcasting Union |
| ASCII |
American Standard Code for Information Interchange |
| ASCO |
Arab Satellite Communications Organisation |
| ASDS |
Autonomous Spaceport Drone Ship |
| ASEAN |
Association of South East Asian Nations |
| ASI |
Asynchronous Serial Interface |
| ASIC |
Application Specific Integrated Circuit |
| ASK |
Amplitude Shift Keying |
| ASM |
Advanced Satellite Mobile |
| ASM |
Attached Synchronisation Marker |
| ASMS-TF |
Advanced Satellite Mobile Systems – Task Force |
| ASPR |
Automatic Satellite Position Report |
| ASR |
Automatic Send and Receive |
| ASS |
Amateur Satellite Service |
| ASSR |
Acquisition and Steady State Reception Procedure |
| ASU |
Acquisition and Synchronisation Unit |
| AT |
Acceptance Test |
| ATB |
All Trucks Busy |
| ATB |
Avionics Test Bench |
| ATC |
Adaptive Transform Coding |
| ATC |
Ancillary Terrestrial Component |
| ATDA |
Augmented Target Docking Adaptor |
| ATDE |
Adaptive Time Domain Equaliser |
| ATIS |
Automatic Transmitter Identification System |
| ATM |
Asynchronous Transfer Mode |
| ATM |
Automatic Teller Machine |
| ATME |
Automatic Transmission Measuring Equipment |
| ATP |
Acceptance Test Procedure |
| ATU |
Arab Telecommunications Union |
| ATV |
Advanced Technology Vehicle |
| AU |
Astronomical Unit |
| AUC |
Authentication Centre |
| A/V |
Audio Visual |
| AVC |
Advanced Video Coding |
| AVD |
Alternate Voice/Data |
| AVI |
Avionics Operator |
| AWG |
American Wire Gauge |
| AWGN |
Additive White Gaussian Noise |
| AZ |
Azimuth |
