The importance in support of data communication for mobile communication networks is increasing. New requirements for mobile networks are raised for new data services, like sending and receiving E-mails, browsing to IP-based networks. The increasing need for bandwidth cannot be adequately fulfilled by the GSM standard.
The General Packet Radio Service as an extension to Second generation GSM provides virtual connections, short connection setup times and data rates up to 115 kbit/s for each user, whereas the available bandwidth can be shared among different users. The high bandwidth will be achieved.
In a GSM Network Base Station Controller (BSC) splits or combines the voice and data traffic dependent on the direction. Voice traffic is sent to a GSM network while data traffic is transported via a separated IP-based backbone network. Two new types of nodes are introduced in GPRS, the Serving GPRS Support Node (SGSN) and the Gateway GPRS Support Node (GGSN). The GGSN is responsible for the connection to other packet oriented networks and stores the information about the location of the GPRS users. The SGSN, like the MSC in the GSM-network, is responsible for the support of user mobility and the access control of users to the radio resources. The GPRS network is only connected with the GSM Network at the BSC