# 3G : UMTS/HSPA/HSPA+

**3G** brought **mobile internet** to the mainstream. Where 2G was built for voice
and SMS, 3G (**UMTS**, then **HSPA/HSPA+**) switched to WCDMA on the air interface
and pushed data rates from tens of kbps into the **multi-Mbps** range — enough for
video calls, web browsing and the first smartphone apps.

**Key points:**

* Air interface: **WCDMA** (wideband CDMA), later HSPA/HSPA+ for faster data
* Typical data speeds: **384 kbps → 42 Mbps** (HSPA+)
* Stronger authentication than 2G (mutual auth, USIM) — no trivial A5/1-style break
* Being shut down worldwide in favour of 4G/5G, but still instructive to study

## Quick Access

```{toctree}
:maxdepth: 1
evolution.md
tutorial.md
```