6.9.0 General

23.0603GPPGeneral Packet Radio Service (GPRS)Release 17Service descriptionStage 2TS

The Location Management function provides:

– mechanisms for cell and PLMN selection;

– a mechanism for the network to know the Routeing Area for MSs in STANDBY, PMM‑IDLE, READY, and PMM‑CONNECTED states;

– a mechanism for the 2G‑SGSN to know the cell identity for MSs in READY state;

– a mechanism for the Iu mode RAN to know the RAN registration area identity or cell identity for MSs in PMM‑CONNECTED state;

– a mechanism for the Iu mode RAN to indicate to an MS in RRC Connected mode when a Routeing Area Update procedure shall be performed by providing the RAI; and

– a mechanism for the network in Iu mode to know the address of the serving BSC/RNC handling an MS in PMM‑CONNECTED state. This mechanism is the serving RNC relocation procedure.

NOTE 1: The SGSN may not know the Routeing Area where the Iu mode MS is physically located for an MS is in RRC Connected mode. An MS in PMM‑CONNECTED state is necessarily in RRC Connected mode. An MS in PMM‑IDLE state is in RRC Connected mode only if the MS is in CS MM‑CONNECTED state.

In Iu mode, the tracking of the location of the MS is on three levels (cell, RAN area, or RA); see TS 23.121 [54].

In A/Gb mode, the tracking of the location of the MS is on two levels (cell or RA).

Routing Area Update procedure may be triggered by a PS Handover procedure as described in TS 43.129 [87].

Routing Area Update procedure may be triggered by an Inter RAT Handover from EUTRAN to GERAN/UTRAN as described in TS 23.401 [89].

Routing Area Update procedure may be triggered by the ISR function as described in TS 23.401 [89].

Other specified events may also trigger the Routing Area Update procedure.

Routeing Area (RA) is defined in clause "Routeing Area Identity".

Emergency bearer service is not supported in GERAN PS domain. Relocation to A/Gb mode shall be prevented if an MS in UTRAN with emergency bearer services tries to handover to GERAN PS domain.

If SIPTO using GW selection is enabled for a PDN connection, the SGSN should re-evaluate whether the PGW/GGSN location is still acceptable. If the SGSN determines that GW relocation is needed, the SGSN may initiate PDN deactivation with reactivation requested according to clause 9.2.4.2 at the end of the routing area update procedure.

NOTE 2: It depends on the operator’s configuration in the SGSN whether to use the deactivation with reactivation request or allow the continued usage of the already connected GW.