Different interfaces are used for routing between network nodes in GPRS.
*Um interface provides communication between MS and BSS.
*Gb interface provides connection between BSS and SGSN.
*Gn interface provides connection between SGSN and GGSN within the same GPRS network.
*Gp interface provides connection between SGSN and GGSN when they are in different GPRS network.
*Gi interface provides connection between GGSN and external networks.
*Gs interface provides communication between MSC and SGSN.
GPRS functional Groups
The functions which are defined in GPRS are following.
*Network access function: Point to point data transfer, registration of MS with packet data protocols, radio resources for MS communication and charging information about packet transmission, is provided by this function.
*Packet routing and transfer function: Routing of data between an MS and destination, conversion of GPRS address to external address and forwarding of packets between an MS and GGSN, is provided by this function.
*Logical link management function: The communication between an MS and the GSM network is maintained by it.
*Radio resources management function: Radio communication paths are allocated by it.
*Mobility management function: Current location of an MS is kept by it. When an MS is entered to a new area, all routing and location in formations are also updated by it.
*Network management function: If provides mechanisms to support network functions related to GPRS
