7 Reference points between the PLMN and other networks
23.0023GPPNetwork architectureRelease 17TS
The reference points between the PLMN and other networks, including dedicated networks, are described in the 49-series of Technical Specifications and in the 29-series of Technical Specifications.
7.1 Reference point fixed networks – MSC
The MSC is based on a normal ISDN exchange. It has, for call control, the same reference points as the fixed network exchanges. The signalling reference point considered in the Technical Specifications is related to the signalling system No. 7 User Parts TUP and ISUP associated to the circuits used for incoming and outgoing calls.
7.2 Reference point GGSN – packet data networks (Gi reference point)
This is the reference point between the GGSN and a packet data network. It may be an operator external public or private packet data network or an intra operator packet data network, e.g. for provision of IMS services.
7.2a Reference point PDN GW – packet data networks (SGi reference point)
This is the reference point between the PDN GW and a packet data network. It may be an operator external public or private packet data network or an intra operator packet data network, e.g. for provision of IMS services. For more details see TS 29.061 [104].
7.3 Reference point GMLC – external LCS Client (Le reference point)
At this reference point external LCS Clients request services from the PLMN.
7.4 Reference Point CSCF/IBCF – Multimedia IP networks (Mm Reference Point)
This is an IP interface between CSCF/IBCF and IP networks. This interface is used, for example, to receive a session request from another SIP server or terminal.
7.5 (void)
7.6 Reference point PDG – packet data networks (Wi reference point)
This is the reference point between the PDG and a packet data network. It may be an operator external public or private packet data network or an intra operator packet data network, e.g. for provision of IMS services.
7.7 Reference Point WAG – WLAN access network (Wn reference point)
This is the reference point between the WAG and the WLAN access network. It is used to force traffic between a WLAN UE and PDG to go through the WAG.
7.8 Reference point MTC-IWF – SCS (Tsp reference point)
See clause 6a.16.1.
This interface is an interface between the PLMN and other networks if the SCS is not controlled by the operator.
Annex A (informative):
Description for GLR-related entities and interfaces
This annex describes the GLR-related entities and the interfaces. This annex is an informative annex. The ‘informative’ means just that the GLR is an optional functional entity to optimize signalling traffic between PLMNs. Therefore, this annex is normative to a PLMN which introduce the GLR.
The GLR is only applicable for GERAN and UTRAN access. The GLR is not applicable to the EPC.