| Abbreviation | Definition |
|---|---|
| TGB | Telecommunications Grounding Busbar |
| TGPSI | Transmission Gap Pattern Sequence Identifier |
| THGR | Telecommunications Heritage Group Resource |
| THINK | Telecom Hardware Infrastructure Networking and Knowledge |
| THK | TeleHallintoKeskus (Finnish: Telecommunications Administration Centre) |
| THL | Trans-Hybrid Loss |
| THT | Total Handling Time |
| TI | Telecom Implementation |
| TIA | Telecommunications Industry Association |
| TIC | Talking In Confidence |
| T-IC | T-interConnect |
| TICI | Telecommunication Infrastructure Company of Iran |
| TICS | Telecommunications And Instructional Computing Support |
| TIE | Telephone Interconnect Equipment |
| TIE | Telephone Interconnect Expansion |
| TIF | Telecommunications Infrastructure Fund |
| TIM | Telecom Idea Management |
| TIM | Telecommunications Internet and Media |
| TIMS | Telecommunication Instructional Modeling System |
| TIMS | Telecommunications Instructional Modeling System |