1. What is 3G?
3G (Third Generation) mobile networks launched around 2001. The main standard, UMTS (Universal Mobile Telecommunications System), used W-CDMA (Wideband CDMA) radio technology.
3G brought real mobile internet ā web browsing, video calls, and download speeds of 384 kbps to 42 Mbps (with HSPA+).
Key Fact: The first 3G network launched in Japan (NTT DoCoMo) in 2001.
2. UMTS Architecture
UMTS introduces the UTRAN (UMTS Terrestrial Radio Access Network):
- UE (User Equipment) ā Your 3G phone with USIM card
- Node B ā The 3G base station (equivalent to GSM's BTS)
- RNC (Radio Network Controller) ā Controls Node Bs, manages handovers and radio resources
- SGSN ā Serving GPRS Support Node (packet data)
- GGSN ā Gateway GPRS Support Node (connects to internet)
3. Services
| Technology | Speed | Generation |
|---|---|---|
| UMTS | 384 kbps | 3G |
| HSDPA | 14.4 Mbps | 3.5G |
| HSUPA | 5.76 Mbps | 3.5G |
| HSPA+ | 42 Mbps | 3.75G |
4. 3G vs 2G
| Aspect | 2G (GSM) | 3G (UMTS) |
|---|---|---|
| Radio | TDMA/FDMA | W-CDMA |
| Max speed | 384 kbps (EDGE) | 42 Mbps (HSPA+) |
| Video calls | No | Yes |
| Security | One-way auth | Mutual auth (USIM) |
| Channel width | 200 kHz | 5 MHz |