In short, the GPRS provides:
· efficient use of scarce radio resources
· a flexible service, with volume-based (or session duration-based) charging
· fast set-up/access time
· efficient transport of packets in the GSM network
· simultaneous GSM and GPRS, co-existence without disturbance
· connectivity to other external packet data networks, using the Internet Protocol.
The above gives the possibility for services beyond GSM, and opens up for customer segments beyond GSM. Machine-to-machine communication is one example. The GPRS makes use of the GSM radio network.
The GPRS system supports open interfaces, for maximum flexibility. For example, the interface between the Serving GPRS Support Node and the BSC is an open interface in accordance with the ETSI GSM standard for GPRS.
The parts of the GSM System that realise the switching of packet data are called the Serving GPRS Support Node (SGSN) and the Gateway GPRS Support Node (GGSN). The SGSN provides packet routing to and from the geographical SGSN service area. The GGSN realises the interface towards the external IP packet networks. Operation and maintenance of a GSN node typically is done from a management client like the GSM OSS or the GPRS Terminal, EGT, or a PC with a browser and the GSN acting as a server. This course describes the first release of the SGSN/GGSN system. The SGSN/GGSN is physically separated from the circuit-switched part of the GSM System. The other parts of the GPRS architecture utilise existing GSM network elements. A more detailed summary of the parts of the GPRS System, including its circuit-switched environment and its updates for GPRS, is found under the "GPRS System Overview" section.
