General Packet Radio Service or GPRS is the name for the packet-switched service for data transmission in GSM networks. General Packet Radio Service is based on the GSM. If General Packet Radio Service is activated, only virtually permanent connection to the remote site (so-called always-on mode) exists. Only when data is actually transmitted, the it is occupied, otherwise it is free for other users. Therefore, no channel needs a permanent basis to be reserved for a user. General Packet Radio Service accounts are therefore mainly dependent on the quantity of data transferred rather than the connection time. However, this is also dependent on the particular contract terms with the operator.
How General Packet Radio Service works
Unlike the circuit-switched data services, General Packet Radio Service or GPRS is packet-oriented. That is, the data at the transmitter into individual packages transformed, transferred as such and at the receiver it is reassembled. General Packet Radio Service technology allows for the pooling of all eight GSM – time slots of a channel, a data transfer rate of 171.2 kilobits per second. In practical operation, the number of usable time slots within a frame, however, by the ability of the mobile station and limited by the networks. The achievable data transmission rate is – depending on the coding scheme (depends on the signal and noise ratio) and dependent on the network capacity number of allocated time slots (time slots) – up to 53.6 kilobits per second. This roughly corresponds to the speed of a V.90 telephone modem.

There are three different classes of devices which provide the basic capabilities of a terminal. The terminal class is specified with a letter A, B and C.
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More points on General Packet Radio Service
Most new mobile phones support General Packet Radio Service, such as data transmission service for viewing WAP pages. The multimedia messaging service (MMS) is also based on General Packet Radio Service. Often a computer or handheld with the GPRS-enabled mobile phone can be connected to these devices, a full-fledged Internet access. The phone then acts as a modem, there are small General Packet Radio Service modem do similar task. General Packet Radio Service is also particularly suitable for remote tasks. Biggest advantages of General Packet Radio Service in remote operation is the network coverage and availability of GSM as well as lower investment compared to other transmission techniques. Another application of General Packet Radio Service is the tracking of vehicles and objects and telemetry data. Furthermore, General Packet Radio Service is used for Push-to-talk.
