GPRS Network composition and interface

GPRS Network composition and interface
GB Port: SGSN through the GB port and base station BSS, for mobile MS Services. Establish a connection between SGSN and Ms through the Logical Control Protocol LLC, providing mobility management (location tracking) and security management functions. SGSN completes the protocol conversion between MS and SGSN, i.e. backbone network uses IP protocol to convert into SNDCP and LLC protocols, and provides MS authentication and registration functions.

GN Port: SGSN through the GN Port and GGSN, through the GPRS Tunneling Protocol (GTP) to establish a channel between SGSN and external data network (X.25 or IP) to achieve the interconnection between MS and external data network.

GS mouth: For SGSN to MSC/VLR send address information, and from the MSC/VLR to receive paging requests, to achieve packet-type business and the association of non-grouped business.

GR Port: HLR Save GPRS user data and routing information (IMSI, SGSN address), each IMSI also contains packet data protocol PDP information, including PDP type (X.25 or IP), PDP address and its QoS level and routing information.

GI mouth: GGSN through the GI port to achieve the GPRS network and external Data Network (PDP) interconnection. GGSN is actually two Internet gateways, GPRS itself belongs to IP domain network, GI port support X.25 and IP protocol. Viewed from the PDN network GGSN,GGSN can be seen as a router connected to the PDN network. The GGSN contains routing information for connecting GPRS users, and provides channels for the PDU of the external data network to be delivered to Ms. Through GGSN and GPRS network interconnection packet Data network PDN, can be PSPDN network, at this time, GPRS support ITU-T X.121 and ITU-T E.164 numbering Scheme provides X.25 virtual circuit and quick selection of X.25, also supports x.75 protocol connection between networks, or Internet network, based on IP protocol, GPRS supports TCP/IP header's compression function in IP datagram transmission mode.

GD Port: Sms_gmsc, Sms_inmsc and SGSN indirect port. Through this interface, SGSN can receive short message, and transfer it to MS, SGSN and SMS Service center-GMSC, through GD interface to complete the short message service on GPRS

GP Mouth: GPRS network indirect port. Using GP interface interconnection among different GPRS networks, the abbreviations are composed of gateways and firewalls.

Drx	Non-continuous receive
Em	Extended measurement
Gprs	General Packet Radio Service
Gsm	Global Mobile Communication System
Llc	Logical Link Control
Mac	Media access Control
Mm	Mobility Management
Ms	Mobile Station
Pacch	Packet along-Path control channel
Pagch	Packet Access permitted Channel
Pbcch	Packet Broadcast control channel
Pccch	Packet public control channel
Pdp	Packet Data Protocol
Pdu	Grouped data units
Pdch	Packet data channel
Pdtch	Packet Service Channel
PLMN	Public Land mobile Network
Ppch	Packet Paging channel
Prach	Packet Random access Channel
PSDN	Packet Switched Data network
Ptcch	Group Time Advance Channel
Rr	Wireless Resources
Rlc	Wireless Link Control
SI	System Information
SGSN	Service GPRS Support node
Sndcp	Subnet-dependent Convergence protocol
TBF	Temporary flow identification
TFI	Temporary flow identification
Tlli	Temporary logical link recognition
Tqi	Temporary queue recognition
USF	Uplink status Tag