The present document defines the stage 2 service description for the General Packet Radio Service (GPRS) which is a packet bearer service and a main part of the packet domain. ITU-T Recommendation I.130  describes a three-stage method for characterisation of telecommunication services, and ITU-T Recommendation Q.65  defines stage 2 of the method. The GPRS described in the present document is also the description of the GERAN and UTRAN related functionality of the Evolved Packet System (EPS) according to TS 23.401.
The present document does not cover the Radio Access Network functionality. TS 43.064 contains an overall description of the GSM EDGE Radio Access Network (GERAN). TS 25.401 contains an overall description of the Universal Terrestrial Radio Access Network (UTRAN). TS 43.051 contains an overall description of GSM/EDGE Radio Access Network.
The present document does not cover the functionality of the GPRS enhancements for the Evolved Universal Terrestrial Radio Access Network (E UTRAN). This functionality and also the interoperation functionality between E-UTRAN and GERAN/UTRAN accesses are described in TS 23.401.
The present document specifies functions, procedures and information which apply to GERAN Iu mode. However, functionality related to GERAN Iu mode is neither maintained nor enhanced since Rel 9.
The following documents contain provisions, which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. For a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
ITU-T Recommendation X.25: "Interface between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit".
Definitions can be found in TS 22.060 and TS 25.401. For the purposes of the present document, the following terms and definitions apply:
GERAN/UTRAN PS coverage:
an MS is defined to be in GERAN/UTRAN PS coverage if it can access GPRS services via GERAN or UTRAN. These services may be provided in A/Gb mode or in Iu mode. According to this definition, an MS camped on an E-UTRAN cell is not in GERAN/UTRAN PS coverage.
packet bearer service of the packet domain.
indicates that this clause or paragraph applies only to a system or sub-system which operate in A/Gb mode of operation, i.e. with a functional division that is in accordance with the use of an A or a Gb interface between the radio access network and the core network. This definition is consistent with the A/Gb mode definition for the RAN in TS 43.051.
indicates that this clause or paragraph applies only to a system or a sub-system which operates in Iu mode of operation, i.e. with a functional division that is in accordance with the use of an Iu-CS or Iu-PS interface between the radio access network and the core network. This definition is consistent with the Iu mode definition for the RAN in TS 43.051. Note that Iu mode is independent of the support of both parts of the Iu interface, e.g. an SGSN in Iu mode uses only the Iu-PS interface.
change of an MS from A/Gb mode to Iu mode of operation and vice versa.
this specification makes no distinction between MS and UE
2G / 3G :
prefixes 2G and 3G refer to systems or sub-systems, that support A/Gb mode or Iu mode, respectively, e.g. 2G SGSN refers to all functionality of an SGSN which serves an MS in A/Gb mode.
refers to a grouping of one or more RA(s) that, from a RAN perspective, are served by a certain group of CN nodes, as defined for the Intra Domain Connection of RAN Nodes to Multiple CN Nodes.
Emergency attached MS:
An MS which only has PDP context(s) related to emergency bearer service.
LIPA PDN connection:
a PDN connection for local IP access for a UE connected to a HNB.
SIPTO at local network PDN connection:
a PDN connection for SIPTO at local network for a UE connected to a HNB.
For a LIPA PDN connection, Correlation ID is a parameter that enables direct user plane path between the HNB and L-GW.
SIPTO Correlation ID:
For a SIPTO at local network PDN connection, SIPTO Correlation ID is a parameter that enables direct user plane path between the HNB and L-GW when they are collocated.
Local Home Network:
A set of (H)NBs/RNCs and L-GWs in the standalone GW architecture, where the HNB-GWs/RNCs have IP connectivity for SIPTO at the Local Network via all the L-GWs.
Local Home Network ID:
An identifier that uniquely identifies a Local Home Network within a PLMN.
Presence Reporting Area:
An area defined within 3GPP Packet Domain for the purposes of reporting of UE presence within that area due to policy control and/or charging reasons. A Presence Reporting Area may consist in a set of neighbour or non-neighbor cells/Service Areas or Routing Areas. There are two types of Presence Reporting Areas: "UE-dedicated Presence Reporting Areas" and "Core Network pre-configured Presence Reporting Areas".
RAN user plane congestion:
RAN user plane congestion occurs when the demand for RAN resources exceeds the available RAN capacity to deliver the user data for a prolonged period of time.
For the purposes of the present document, the following symbols apply:
Charging data collection interface between a CDR transmitting unit (e.g. an SGSN, S-GW, PDN-GW or a GGSN) and a CDR receiving functionality (a CGF).
Interface between an SGSN and a BSS.
Interface between a GGSN and an HLR.
Interface between an SMS GMSC and an SGSN, and between an SMS IWMSC and an SGSN (MAP based).
Interface between an SMS GMSC and an SGSN, and between an SMS IWMSC and an SGSN (Diameter based).
Interface between an SGSN and an EIR.
Reference point between a GGSN and a packet data network.
Interface between two SGSNs within the same or different PLMNs or between an SGSN and a GGSN within the same PLMN.
Interface between a SGSN and a P-GW/GGSN in different PLMNs. The Gp interface allows support of GPRS network services across areas served by the co-operating GPRS PLMNs.
Interface between an SGSN and an HLR.
Interface between an SGSN and an MSC/VLR.
Interface between the RNS and the core network. It is also considered as a reference point.
Kilobits per second.
Megabits per second. 1 Mbit/s = 1 million bits per second.
Interface between an RCAF and the PCRF.
Interface between an S4-SGSN and an RCAF.
Reference point between a non-ISDN compatible TE and MT. Typically this reference point supports a standard serial interface.
The service area for which the location of an MS is reported.
The location accuracy level needed for service management purposes in the 3G SGSN, e.g. a routeing area or a cell. The 3G SGSN can request the SRNC to report: i) the MS's current service area; ii) when the MS moves into a given service area; or iii) when the MS moves out of a given service area.
Interface between a SGSN and a S-GW within the same PLMN.
Interface between a S-GW and a P-GW within the same PLMN.
Interface between a SGSN and a HSS.
Interface between a S-GW and a P-GW in different PLMNs. The S8 interface allows support of GPRS network services across areas served by the co operating GPRS PLMNs
User plane interface between the RNS and a S-GW for Direct Tunnel.
Interface between two SGSNs within the same or different PLMNs when those SGSNs support S4.
Reference point between a P-GW and a packet data network.
Interface between MME and an MSC/VLR.
Interface between the mobile station (MS) and the A/Gb mode network. The Um interface is the MS to network interface for providing GPRS services over the GERAN radio to the MS in A/Gb mode.
Interface between the mobile station (MS) and the Iu mode network. The Uu interface is the Iu mode network interface for providing GPRS services over the UTRAN radio (and in Iu mode, over the GERAN radio) to the MS.
Interface between a SGSN and an EIR within the same or different PLMNs.
The packet domain uses packet-mode techniques to transfer high-speed and low-speed data and signalling in an efficient manner. The packet domain optimises the use of network and radio resources. Strict separation between the radio subsystem and network subsystem is maintained, allowing the network subsystem to be reused with other radio access technologies.
A common packet domain Core Network is used for both Radio Access Networks (RAN) the GERAN and the UTRAN. This common Core Network provides together with these RANs GPRS services. It is designed to support several quality of service levels to allow efficient transfer of non real-time traffic (e.g. intermittent and bursty data transfers, occasional transmission of large volumes of data) and real-time traffic (e.g. voice, video). Applications based on standard data protocols and SMS are supported, and interworking is defined with IP networks. Charging should be flexible and allow to bill according to the amount of data transferred, the QoS supported, and the duration of the connection.
The Serving GPRS Support Node (SGSN) keeps track of the location of an individual MS and performs security functions and access control. The SGSN is connected to the GERAN base station system through the Gb or Iu interface and/or to the UTRAN through the Iu interface. The SGSN also interfaces via the GPRS Service Switching Function with the GSM Service Control Function for optional CAMEL session and cost control service support.
The Gateway Node (P-GW/GGSN) provides interworking with packet data networks, and is connected with other core network nodes via an IP-based packet domain PLMN backbone network.
The Serving Gateway is user plane node that provides a common anchor for interoperation between GERAN/UTRAN and E-UTRAN accesses and when S4 is used it permits Direct Tunnel usage in roaming scenarios.
The Offline Charging System (OFCS) collects charging records from SGSNs, S-GWs and P-GW/GGSNs.
The HSS/HLR contains subscriber information.
The SMS GMSCs and SMS IWMSCs support SMS transmission via the SGSN.
Optionally, the MSC/VLR can be enhanced for more-efficient co-ordination of packet-switched and circuit-switched services and functionality: e.g. combined GPRS and non-GPRS location updates.
In order to use GPRS services, an MS shall first make its presence known to the network by performing a GPRS attach. This makes the MS available for SMS over GPRS and SMS over IMS, paging via the SGSN, and notification of incoming packet data. If the UE is already PS attached due to an attach via E-UTRAN it makes its presence known to an SGSN by a Routeing Area Update.
In order to send and receive packet data by means of GPRS services, the MS shall activate the Packet Data Protocol context that it wants to use. This operation makes the MS known in the corresponding P-GW/GGSN, and interworking with data networks can commence.
User data are transferred transparently between the MS and the packet data networks with a method known as encapsulation and tunnelling: data packets are equipped with GPRS-specific protocol information and transferred between the MS and the P-GW/GGSN. This transparent transfer method lessens the requirement for the PLMN to interpret external data protocols, and it enables easy introduction of additional interworking protocols in the future.
Packet Switched (PS) handover is introduced in order to support real-time packet-switched service with strict QoS requirements on low latency and packet loss. PS handover reduces the service interruption of the user plane information at cell change compared to the cell-reselection and enables methods to improve buffer handling of user plane data in order to reduce packet loss at cell-change. PS handover is the handover between GERAN PS and UTRAN PS. The complete specification of the PS handover procedures for A/Gb mode and between Iu mode and A/Gb mode are described in TS 43.129.
Earlier release versions of this specification described a Network Mode Operation III, which is not available for deployment as GERAN specifications forbid deploying Packet Common Control Channels since Release 9 in TS 44.060.