General packet radio service (GPRS) is a type of data service used on second-generation (2G) and third generation (3G) mobile wireless networks. A GPRS card is a type of network card, a piece of hardware used to enable other hardware, like a computer or personal digital assistant (PDA), to connect to a GPRS network. Generally attached to a computer via universal serial bus (USB) or to a portable device via removable media card like a GPRS sim card, a GPRS card can also be called a GPRS modem or GPRS adapter.
In most devices that use it, GPRS is a built-in capability in the hardware device. The size and appearance of a GPRS card will vary depending on the hardware in which it is installed and used. If it is used primarily on one type of network, a GPRS card may be called a 2G or 3G card. A GPRS card differs from a wifi card because it does not connect to an Internet connection broadcast on a router. This type of card connects to the signal broadcast from cell towers by mobile communications companies.
Three classes of GPRS hardware, called classes A, B, and C. Each class of GPRS card handles the transition between voice and short message service (SMS) differently. Class A hardware can use both SMS and voice at the same time. A GPRS card that fits into class B can only use either SMS or voice, not both at once, but switches between the two automatically. Class C requires manual activation of voice and SMS services on the devices.
Some mobile devices equipped with GPRS capabilities have the ability to connect to 2G and 3G connections as well as private routers with open Internet access. One example of a mobile communications device with this feature is the iPhone 3G. A feature allowing the user to switch to a router for Internet connectivity is helpful for mobile communications users because router connections are usually faster than GPRS connections.
A means of transmitting mobile data, 2G is an all-digital In the United States, 2G is more frequently called personal communications service (PCS). First generation (1G) generally refers to analog mobile phone technology used prior to 2G. The successor to 2G technology is 3G technology, which is also called International Mobile Telecommunications-2000 (IMT-2000). 3G is a faster technology that also allows the user to use voice capabilities at the same time as the data network.