Mobile broadband

Mobile broadband (also known under a variety of names like 3G, HSDPA, UMTS, etc.) is a method of reasonably fast Internet access using an existing cell phone network. Mobile broadband is available wherever there is mobile phone coverage, though bandwidth will vary. The speed can be as low as 48 kbps (on basic GSM networks via GPRS) or as high as 7.2 Mbps (on UMTS networks, typically deployed in cities, using HSDPA). Be sure to get a modem or phone that can support all networks available in your area. Choosing the highest speed network is done by the modem, so you don't need to worry about it.

To connect to a mobile broadband network, you will need the following:
 * 1) Modem hardware, which can be:
 * 2) * Mobile phone which can connect to your computer using Bluetooth, USB, etc. and does not have restrictions on tethering. Most phones bought separately or received with a plan outside of US will work. Phones received with a plan in the US will probably not work. In particular, iPhones from AT&T will not work unless jailbroken.
 * 3) * Dedicated modem - they are usually PCMCIA cards (PC Cards), ExpressCards, or USB dongles. You can buy them separately or receive them with a subscription.
 * 4) SIM card that can log into the network. You can get one either via a subscription service from a 3G or cell provider, or you can use pre-paid cards. Pre-paid cards typically have higher rates, but do not have monthly fees. If you received the phone with a plan, you already have this. You can also reuse SIM cards from mobile phones in modems.

Compatible hardware

 * Most PCMCIA, USB and ExpressCard modems will work out of the box with no setup beyond choosing the broadband provider. Some of those have a mode that causes them to be detected as CD-ROMs with Windows drivers. Modern kernels should automatically switch them into modem mode, but for some devices it might be necessary to use USB Modeswitch.
 * Cell phones with an RFCOMM modem interface over Bluetooth (most older phones) will work with some manual setup.
 * Cell phones with a PAN interface (Windows Mobile devices and smartphones) are currently hard to get working, but this should improve with the next release of Network Manager (0.8).

Setup
It is recommended to use the GNOME's Network Manager applet to configure internal modems. For PCMCIA, USB and ExpressCard modems, use the dmesg command to verify that the modem was detected. If it was, use the Network Manager applet. Left click on it and select "Configure" under the heading "Mobile Broadband". Select your country and provider from the list. Once you're done, a new entry should appear under the "Mobile Broadband" heading - click it to connect to the network. That's all!

For instructions how to do it, see set up UMTS.