May also be referred to as "wireless broadband." Mobile broadband encompasses any services that deliver Internet access over the same cell towers used for mobile phones. Mobile broadband is much more portable than fixed wireless broadband services, which require separate towers and typically offer inferior coverage and speed.
Second-generation mobile telephony and data services. GSM refers to the mobile network that is still being used today to provide mobile phone calls and a basic data connection — either GPRS or the slightly faster EDGE — that is best suited to text-based Internet services and Multimedia Messaging (MMS). GPRS and EDGE services are also used as a fallback when mobile broadband devices lose 3G or HSPA reception.
Third-generation mobile data services, primarily designed for mobile broadband access. These services are combined under the umbrella of a UMTS network. 3G is the original form of mobile broadband, but it has since been superseded by HSPA (also referred to as 3.5G or HSDPA) services, which provide bandwidth speeds of between 3.6Mbps and 42Mbps depending on the carrier. Devices must be compatible with these networks and specified speeds in order to receive the full bandwidth.
Competing fourth-generation mobile broadband technologies. LTE, or Long Term Evolution, operates over the same cell towers used for mobile phones, though it requires compatible devices (which aren't currently available). WiMAX is similar to fixed wireless broadband: it requires separate infrastructure and only offers maximum speeds of up to 12Mbps. It is best suited to use around the home, rather than on the go.
A small card that must be inserted in mobile phones and mobile broadband modems in order to identify you and allow the carrier to charge your account. In many cases the SIM card must be specifically enabled for data in order to facilitate mobile broadband.
The amount you are allowed to download in one billing cycle, usually a month. Once this quota has been reached, the mobile broadband carrier will either charge you for excess usage or slow your Internet access, depending on which plan you chose. Excess usage charges are often extremely high, so a plan that slows your access (otherwise known as "shaping") is preferable.