2G (GSM)
Cellular Generations · 8 specs
Direct Answer
2G (Second Generation Cellular) revolutionized mobile communications in 1991 by transitioning from analog 1G to digital TDMA/FDMA. Governed by 3GPP GSM standards, it introduced Subscriber Identity Module (SIM) cards, SMS text messaging, GPRS packet data (up to 114 kbps), and 8PSK-modulated EDGE (up to 384 kbps).
Source: ETSI / 3GPP GSM Specifications / ITU-R · Last reviewed Aug 28, 2026
Specs
| Standardization Body | ETSI (European Telecommunications Standards Institute) / 3GPP |
| Commercial Launch Year | 1991 (Radiolinja Finland) |
| Multiple Access Technology | TDMA (Time Division Multiple Access) + FDMA (200 kHz channels) |
| Primary Frequency Bands | 900 MHz and 1800 MHz (EU/Asia) / 850 MHz and 1900 MHz (US) |
| Basic Circuit-Switched Voice Rate | 13 kbps (Full Rate Speech Codec) |
| GPRS Packet Data Rate (2.5G) | Up to 114 kbps (CS-1 through CS-4 coding) |
| EDGE Data Rate (2.75G) | Up to 384 kbps (8PSK modulation) |
| Key Milestone Features | SIM Card (Subscriber Identity Module), SMS (Short Message Service), A5/1 encryption |
The Digital Voice Revolution and SIM Architecture
Launched in 1991, GSM replaced noisy, unencrypted analog networks (1G AMPS, NMT, TACS). GSM digitized voice via Regular Pulse Excitation (RPE-LPC) codecs into 8 time slots per 200 kHz RF carrier. By decoupling the user's subscription from the handset hardware through the removable smart card SIM (ISO/IEC 7816), GSM enabled international global roaming.
Transition to Packet Data: GPRS and EDGE
To transition from voice-only circuit switching to internet data, 3GPP introduced General Packet Radio Service (GPRS, 2.5G) in 2000, allowing 'always-on' IP packet connectivity. Enhanced Data rates for GSM Evolution (EDGE, 2.75G) followed in 2003, upgrading modulation from GMSK to 8PSK to triple data throughput to 384 kbps on existing 200 kHz GSM carrier allocations.