| Abbreviation | Definition |
|---|---|
| BU | Back Up |
| BUC | Block Up-Converter |
| BUPT | Beijing University of Posts and Telecommunications |
| BUR | Bandwidth Usage Redundancy |
| BWRC | Berkeley Wireless Research Center |
| BWX | Broadband Wireless Exchange |
| BYOP | Bring Your Own Portal |
| C | Collect |
| C | Connection |
| C | Connectivity |
| C/R | Control/Response indication bit |
| CA | Communications Activities |
| CAAS | Communications as a Service |
| CAB | Conformity Assessment Body |
| CABS | Carrier Access Billing System |
| CAC | Carrier Access Code |
| CAC | Connection Admission Control |
| CACH | Call Appearance Call Handling |
| CACT | Center for Advanced Computation and Telecommunications |
| CAIRO | Communications Audio Interface for Remote Operations |