30-07-2012, 02:39 PM
GPRS/ EDGE
GPRS Support Nodes
. SGSN
– (Server and Router)
– Routing built in routers (dynamic and static)
– Security (unlike GSM , ciphering is terminated at SGSN
– Auth. Has VLR functionality, register attached users
– Mobility management: routing area update, HO sessions
between BSCs, make sure packets are tunneled to correct
GGSN
– Charging: Call detail records CDR), based on IP payload and
session duration.
– SMS: supports interface to SMS-GMSC & SMS-IWMSC
– Session management: negotiate QoS parameters with MS
Protocols
• SNDCP Subnet dependent convergence
protocol:
– Network layer protocol
– MUX network layer users’ data into one logical message,
– encryption,
– Data compression V.42bis algorithm
– TCP/IP header compression is supported.
– segmentation of Network PDU into LLC frames,
– interface between network layer and LLC
– It supports IP, X.25 network layer protocols
– Services PTP, PTM-M, PTM-G.