Content for TS 23.251 Word version: 18.0.0

0 Introduction p. 5

Network sharing is a way for operators to share the heavy deployment costs for mobile networks, especially in the roll-out phase. In the current mobile telephony marketplace, functionality that enables various forms of network sharing is becoming more and more important. These aspects have not really been addressed before Release 6 in 3GPP UTRAN based access networks, before Release 8 in 3GPP E-UTRAN based access networks and before Release 10 in 3GPP GERAN based access networks, although there has been functionality that supports a very basic type of network sharing since the Release 5 versions of the 3GPP specifications.

To cope with 3GPP pre-Release 6 UTRAN UEs and with non supporting 3GPP GERAN UEs, this specification describes extra functionality for MSCs, SGSNs, BSCs and RNCs in order to provide network sharing functionality to "non-supporting UEs".

In this Release of the specifications, all UTRAN and E-UTRAN capable UEs are required to support the UTRAN and E-UTRAN network sharing requirements. Hence the E-UTRAN and MMEs (which were introduced in 3GPP Release 8) do not need functionality to handle "non-supporting UEs".

Scenarios and user requirements are described in TR 22.951, while the current document presents the stage 2 details and descriptions of how these requirements are supported in a 3GPP GERAN, UTRAN and/or E-UTRAN based network.

1 Scope p. 6

The present document covers the details of Network Sharing for GERAN, UTRAN and E-UTRAN. It shows how several core network operators can share one radio access network and details the impacts on the network architecture. All UEs shall comply with existing requirements, among them PLMN selection and system information reception. The present document also defines requirements for network-sharing supporting UEs.

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 22.951: "Service Aspects and Requirements for Network Sharing".

[2]

TR 21.905: "Vocabulary for 3GPP Specifications".

[3]

TS 25.331: "RRC Protocol Specification".

[4]

TS 23.122: "NAS Functions related to Mobile Station (MS) in idle mode".

[5]

TS 32.250: "Telecommunication management; Charging management; Circuit Switched (CS) domain charging".

[6]

TS 32.251: "Telecommunication management; Charging management; Packet Switched (PS) domain charging".

[7]

TS 24.008: "Mobile radio interface Layer 3 specification; Core network protocols; Stage 3".

[8]

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

[9]

TS 23.401: "Technical Specification Group Services and System Aspects; GPRS enhancements for E-UTRAN access".

[10]

TS 36.300: "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access (E-UTRAN); Overall description; Stage 2".

[11]

TS 36.331: "Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification".

[12]

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

[13]

TS 25.413: "UTRAN Iu interface, Radio Access Network Application Part (RANAP) signalling".

[14]

TS 36.413: "Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP)".

[15]

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

[16]

TS 44.018: "Radio Resource Control RRC Protocol Specification".

[17]

TS 25.467: "UTRAN architecture for 3G Home Node B (HNB); Stage 2".

[18]

TS 22.042: "Network Identity and Time Zone (NITZ); Service description; Stage 1".

[19]

TS 44.064: "General Packet Radio Service (GPRS); Mobile Station - Serving GPRS Support Node (MS SGSN) Logical Link Control (LLC) layer specification".

[20]

TS 23.041: "Technical realization of Cell Broadcast Service (CBS)".

[21]

TS 29.280: "3GPP Sv interface (MME to MSC, and SGSN to MSC) for SRVCC".

[22]

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

[23]

TS 22.011: "Service Accessibility".

[24]

TS 48.018: "General Packet Radio Service (GPRS); Base Station System (BSS) - Serving GPRS Support Node (SGSN); BSS GPRS Protocol (BSSGP)".

[25]

TS 48.008: "Mobile-services Switching Centre Base Station System (MSC BSS) interface; Layer 3 specification".

[26]

TS 29.018: "General Packet Radio Service (GPRS); Serving GPRS Support Node (SGSN) Visitors Location Register (VLR); Gs interface layer 3 specification".

[27]

TS 29.118: "Mobility Management Entity (MME) - Visitor Location Register (VLR) SGs interface specification".

3 Definitions and abbreviations p. 7

3.1 Definitions p. 7

For the purposes of the present document, the following terms and definition below apply. Terms and definitions not defined below can be found in TR 21.905.

Conventional network:

A PLMN consisting of radio access network and core network, by which only one serving operator provides services to its subscriber. Subscribers of other operators may receive services by national or international roaming.

Common PLMN:

The PLMN-id indicated in the system broadcast information as defined for conventional networks, which non-supporting UEs understand as the serving operator.

Core network operator:

An operator that provides services to subscribers as one of multiple serving operators that share at least a radio access network. Each core network operator may provide services to subscriber of other operators by national or international roaming.

Gateway Core Network:

A network sharing configuration in which parts of the core network (MSCs/SGSNs/MMEs) are also shared.

Multi-Operator Core Network:

A network-sharing configuration in which only the RAN is shared.

Non-supporting UE:

A UE that does not support network sharing in the sense that it ignores the additional broadcast system information that is specific for network sharing for 3GPP UTRAN and GERAN. In other specifications, the term "network sharing non-supporting UE" may be used.

Supporting UE:

A UE that supports network sharing in the sense that it is able to select a core network operator as the serving operator within a shared network. In other specifications, the term "network sharing supporting UE" may be used.

Anchor PLMN:

With regard to SRVCC from CS to PS, this Anchor PLMN points to the PS domain operator in which the voice media is anchored in Access Transfer Gateway as part of the SRVCC procedure.

3.2 Void

3.3 Abbreviations p. 8

For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.

BSC

Base Station Controller

Core Network

E-UTRAN

Evolved Universal Terrestrial Radio Access Network

eNodeB

E-UTRAN NodeB

gsmSCF

GSM Service Control Function

GERAN

GSM/EDGE Radio Access Network

GUTI

Globally Unique Temporary Identity

GWCN

Gateway Core Network

HLR

Home Location Register

HSS

Home Subscriber Server

MCC

Mobile Country Code

MME

Mobility Management Entity

MNC

Mobile Network Code

MOCN

Multi-Operator Core Network

MSC

Mobile Switching Centre

NITZ

Network Identity and Time Zone

PLMN

Public Land Mobile Network

RNC

Radio Network Controller

SGSN

Serving GPRS Support Node

TMSI

Temporary Mobile Subscriber Identity

User Equipment

UTRAN

Universal Terrestrial Radio Access Network

VLR

Visitor Location Register