3G mobile data works over the same GSM network as GPRS and EDGE, but provides much faster download and upload speeds. All major Australian telcos — including Telstra, Optus, Vodafone, 3 Mobile and Virgin — offer 3G services, which provide speeds of between 384Kbps and 2.4 megabits per second (Mbps) to compatible mobile phones and devices.
HSPA (sometimes referred to as 3.5G or "HSDPA") is an upgrade to existing 3G networks and provides much greater bandwidth. Mobile phones and mobile broadband devices must be compatible with HSPA — not just 3G — in order to take advantage of speeds up to 42Mbps on Telstra's Next G network. Most carriers offer speeds of between 3.6Mbps and 7.2Mbps (which is slightly faster than you would get on an ADSL line). This means devices with HSPA connections are suitable for browsing the Internet, checking e-mails as well as viewing pictures and downloading music. Since HSPA is effectively a replacement for existing 3G infrastructure, GPRS or EDGE reception is still used as fallback if you lose 3G reception.
Long Term Evolution (LTE) is the fourth generation mobile data network that promises bandwidth speeds of up to 1000Mbps as well as greater support for existing Web standards. While some prototype devices have been displayed by manufacturers recently, it is unlikely to become a prevalent standard until more mobile phones and wireless broadband modems offer the functionality.
Though many people use mobile data connections on their mobile phones or smartphones, this isn't the only way you can wirelessly connect to the Internet. Mobile broadband can also be accessed through modems that plug into your computer's USB port or come as a notebook expansion card. Laptops and netbooks are also available with integrated mobile broadband modems, which are typically tied to a particular mobile broadband operator. Alternatively, it is possible to "tether" your mobile phone to your computer, allowing you to use your phone as a temporary broadband modem. Mobile broadband devices access the same networks used for mobile phones and work in the same way (they require a SIM card and the broadband provider will charge your account).
Not all devices are compatible with all carriers. Each mobile telco transmits mobile broadband over a specific portion of the radio spectrum; Telstra, for instance, uses the 850MHz spectrum for its HSPA Next G network. You'll need to make sure your mobile phone, smartphone or mobile broadband modem works over the same radio spectrum as your carrier.
If you purchase your device directly from the carrier, this won't be a problem, but if you are using a modem purchased elsewhere, it may be tied to another carrier or might not be fully compatible. It is best to read the device specifications carefully, and check with the carrier that your modem or mobile phone can be used on the network.
It is also important to note whether a mobile phone or mobile broadband modem is fully compatible with the carrier's speeds. For instance, certain modems may be compatible with 3 Mobile's HSPA network, but might only support 3.6Mbps download speeds, even if the network is capable of delivering bandwidth of up to 7.2Mbps.
One of fixed wireless broadband's advantages over mobile broadband has traditionally been the ability to share a connection between multiple computers. However, this is no longer the case, as many mobile broadband carriers and networking manufacturers offer wireless routers that can distribute both ADSL2+ and 3G mobile broadband connections. Some, like Virgin Mobile's Wi-Fi Modem even let you share a 3G connection without a power point. This means you can use one SIM card and one data connection for multiple computers while out and about.