Content for TR 23.707 Word version: 13.0.0

1 Scope p. 6

An operator may choose to deploy one (or more) dedicated core networks within a PLMN with each core network dedicated for specific type(s) of subscriber. The present document studies and evaluates architectural enhancements required to support dedicated core networks. The specific dedicated core network that serves a UE is selected based on subscription information and operator configuration, without requiring the UEs to be modified.

The technical report covers both assignment of dedicated core network nodes and maintaining the association during mobility. Roaming and network sharing aspects of dedicated core network, and impacts on procedures such as CSFB, SRVCC and rSRVCC will be studied.

Dedicated core networks may be in the PS domain or CS domain or both.

2 References p. 6

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. In the case of 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.

[1]

TR 21.905: "Vocabulary for 3GPP Specifications".

[2] Void.

[3]

TR 21 912: (V3.1.0) "Example 2, using fixed text".
→ to date, withdrawn by 3GPP

[4]

TS 23.401: "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access".

[5]

TS 23.060: "General Packet Radio Service (GPRS); Service description; Stage 2".

[6]

TS 23.272: "Circuit Switched (CS) fallback in Evolved Packet System (EPS); Stage 2".

[7]

TS 23.236: "Intra-domain connection of Radio Access Network (RAN) nodes to multiple Core Network (CN) nodes".

[8]

TS 23.251: "Network Sharing; Architecture and functional description".

[9]

TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3".

3 Definitions and abbreviations p. 6

3.1 Definitions p. 6

For the purposes of the present document, the terms and definitions given in TR 21.905 apply.

3.2 Abbreviations p. 7

For the purposes of the present document, the abbreviations given in TR 21.905 apply.

4 Assumptions and Architecture Requirements p. 7

4.1 General p. 7

4.2 Assumptions p. 7

A dedicated core network is assumed to serve only specific subscriber(s). A dedicated core network comprises one or more MME/SGSN and it may comprise one or more SGW/PGW. When the PGW is part of a dedicated core network, the PCRF may be shared or specific for the dedicated core network.
If the network deploys dedicated core network selection based on both LAPI indication and subscription information (i.e. DECOR feature), then dedicated core network selection based on subscription information by MME/SGSN overrides selection based the LAPI-indication by RAN.
Different dedicated core networks may provide different characteristics and functions.

4.3 Architecture Requirements p. 7

The purpose with a dedicated core network may be to provide specific characteristics and/or functions or isolate specific UEs or subscribers, e.g. M2M subscribers, subscribers belonging to a specific enterprise or separate administrative domain, etc. The main architecture enhancements are to route and maintain UEs in their respective dedicated core network (for UEs with assigned DCN).

The following architecture requirements shall be met by all proposed solutions:

There shall be no impacts to UE.
Support of dedicated core networks shall not require the use of additional PLMN-IDs, e.g. to separate different dedicated core networks.
It shall be possible to deploy multiple dedicated core-networks sharing the same RAN.
The architecture should support dedicated core networks for specific UEs or subscribers.
Networks deploying dedicated core networks may have a common core network (CCN), which may be assigned to UEs when a dedicated core network (DCN) is not available. A common core network might have limitations in terms of characteristics and functionality.
A UE connected to a DCN is supported within that specific DCN and the CCN when needed.
The architecture should support scenarios where the dedicated core-network is only deployed in a part of the PLMN e.g. only one RAT or in a part of the PLMN area. Each dedicated MME/SGSN supports the DECOR related functionality over its entire service area. Heterogeneous (partial) support of a dedicated core network may, depending on operator deployment and configuration, result in service with different characteristics or functionality when the UE is camping outside service area or RAT of the dedicated core network.
Mechanisms shall be supported to enable the redirection of affected attaching/attached UEs to appropriate dedicated core network, e.g. when a dedicated core network is commissioned in a PLMN.
If the dedicated core network is not deployed to serve a particular RAT or service area of PLMN, the UE in that RAT or service area may be served by MME/SGSN from a common core network and may continue to be served by a PGW from the dedicated core network.