| Abbrevation | Expanded as | Abbrevation | Expanded as |
| DTMF | Dual Tone Multi Frequency | CCS | Common Channel Signaling |
| CAS | Channel Associated Signaling | SDH | Synchronous Digital Hierarchy |
| TDM | Time Division Multiplexing | FDM | Frequency Division Multiplexing |
| WDM | Wave Division Multiplexing | TSI | Time Slot Interchange |
| PDH | Plesiochronous Digital Hierarchy | STDM | Statistical Time Division Multiplexing |
| PSTN | Public Switched Telephone Network | PABX | Private Branch Exchange |
| GSM | Global System for Mobile communications | GPRS | General Packet Radio Service |
| 3GPP | 3rd Generation Partnership Project | SDMA | Space Division Multiple Access |
| PDMA | Polarization Division Multiple Access | FDMA | Frequency Division Multiple Access |
| TDMA | Time Division Multiple Access | CDMA | Code Division Multiple Access |
| UMTS | Universal Mobile Telecommunications Systems | PDC | Personal Digital Cellular |
| iDEN | Integrated Digital Enhanced Network | RACH | Random Access CHannel |
| FDL | Facility Data Link | STM | Synchronous Transport Modules |
| ISDN | Integrated Services Digital Network | PLMN | Public Land Mobile Networks |
| DSLAM | Digital Subscriber Line Acess Multiplexer | PAM | Pulse Amplitude Modulation |
| PSK | Phase-Shift Keying | RISC | Reduced Instruction Set Computing |
| DSL | Digital Subscriber Line | FPGA | Field-Programmable Gate Array |
| PAL | Programmable Array Logic | CPLD | Complex Programmable Logic Device |
| RTTTL | Ringing Tones text transfer language | AMPS | Advanced Mobile Phone Service |
| MIDI | Musical Instrument Digital Interface | IMSI | International Mobile Subscriber Identity |
