Content for TR 22.851 Word version: 19.1.0

0… 5… 5.2… 5.3… 5.4… 5.5… 5.6… 5.7… 5.8… 6…

6.1 Considerations on security 7.1 Introduction 7.2 Consolidated Potential Requirements 7.2.1 Description 7.2.2 Genera 7.2.3 Mobility 7.2.4 Network Access Control 7.2.5 Regulatory Services 7.2.6 Charging

6 Other considerations p. 25

6.1 Considerations on security p. 25

Different from MOCN configuration, which routes UE to the core network of a participating operator directly through Shared RAN of hosting operator, Indirect Network Sharing needs to involve the core network of the Hosting NG-RAN Operator in the signaling exchange. The interoperability between the core networks of Hosting NG-RAN Operators and participating operator will expose more information about the subscribers, the operator's policies and operations of respective core networks, especially those irrelevant to Indirect Network Sharing. Therefore, more security relative to user privacy and the operator's policy can be taken into account for the Indirect Network Sharing configuration.

7 Consolidated requirements p. 25

7.1 Introduction p. 25

Potential requirements on Indirect Network Sharing have been identified in Section 5 out of the use cases under the following aspects:

General
Mobility
Network access control
Regulatory services
Charging

These requirements have been especially introduced to support the newly defined network sharing scenario, where a NG-RAN is shared among multiple operators without necessarily assuming a direct connection between the shared NG-RAN and the Participating NG-RAN Operator's core network.

7.2 Consolidated Potential Requirements p. 26

7.2.1 Description p. 26

Indirect Network Sharing is another type of NG-RAN sharing, to facilitate the operators to extend the availability of 5G services to more coverage areas for their subscribers. It can allow NG-RAN resources to be used by two or more operators simultaneously while minimizing the impact on the network and associated services.

The deployment of Indirect Network Sharing is expected to be transparent to the users when they obtain network services in subscribed PLMN as other NG-RAN sharing configuration (e.g., MOCN). The involvement of the core network of the Hosting Operator e.g., for signaling exchange between the users and the core network of Participating Operator could cause exposure of the subscriber's information to the hosting network.

Thus, extra scrutiny is expected to avoid sharing information not needed for the Indirect Network Sharing operation between the hosting operator and the participating operator.

7.2.2 Genera p. 26

Table 7.2.2-1: General requirements

CPR #	Consolidated Potential Requirement	Original PR #	Comment
CPR 7.2.2-001	The 5G system shall be able to support Indirect Network Sharing between the Shared NG-RAN and one or more Participating NG-RAN Operators' core networks, by means of the connection being routed through the Hosting NG-RAN Operator's core network.	[PR 5.1.6-001]	Align with the definitions.
CPR 7.2.2-002	In case of Indirect Network Sharing, the 5G system shall be able to support means for a Participating NG-RAN Operator to provide its information on operator/network name to UEs, e.g., for display to the user.	[PR 5.1.6-002]	Align with the definitions. Updated wording
CPR 7.2.2-003	In case of Indirect Network Sharing, UEs shall be able to access their subscribed PLMN services when accessing a Shared NG-RAN, where the subscribed PLMN is one of the Participating NG-RAN Operators.	[PR 5.2.6-004]	Align with the definitions. Updated wording
CPR 7.2.2-004	Subject to the agreement between hosting operators and the participating operator, the 5G system shall support a mechanism to enable a UE to obtain its subscribed services, including Hosted Services, of participating operator via a Shared NG-RAN using Indirect Network Sharing. NOTE: the requirement assumes no impact to UE.	[PR 5.5.6-001] [PR 5.7.6-001]	Align with the definitions. PRs merged.

7.2.3 Mobility p. 27

Table 7.2.3-1: Consolidated Requirements to Mobility

CPR #	Consolidated Potential Requirement	Original PR #	Comment
CPR 7.2.3-001	In case of Indirect Network Sharing scenario and subject to hosting and participating operators' policies, the 5G system shall support service continuity and minimize the impact on the user experience and service interruptions between different Shared NG-RANs and/or between a Shared NG-RAN and a non-Shared NG-RAN networks.	[PR 5.2.6-002] [PR 5.3.6-001] [PR 5.2.6-003]	PRs merged
CPR 7.2.3-002	In case of indirect network sharing, the 5G system shall enable the Shared NG-RAN of a hosting operator to provide services for inbound roaming users. NOTE: Inbound roaming users may not have a roaming agreement with the hosting operator but only with a participating operator.	[PR 5.4.6-001]	PR modified

7.2.4 Network Access Control p. 27

Table 7.2.4-1: Consolidated Requirements on Network Access Control

CPR #	Consolidated Potential Requirement	Original PR #
CPR 7.2.4-001	In case of Indirect Network Sharing and subject to Hosting and Participating Operators' policies, the 5G system shall support a mechanism to enable a UE with a subscription to a Participating Operator to select an appropriate radio access network (i.e., E-UTRAN, NG-RAN) and/or access an authorized Shared NG-RAN.	[PR 5.3.6-004] [PR 5.3.6-003]
CPR 7.2.4-002	In case of Indirect Network Sharing and subject to Hosting and Participating Operators' policies, the 5G system shall support access control for a UE accessing a Shared NG-RAN and be able to apply differentiated access control for different access networks of Shared NG-RANs when more than one Shared NG-RAN are available for the Participating Operator to choose from.	[PR 5.3.6-002] [PR 5.7.6-003]
CPR 7.2.4-003	In case of Indirect Network Sharing, based on the Hosting and Participating Operators' policies, the 5G system shall enable the Participating Operator to provide steering information in order to assist a UE with access network selection amongst the Hosting Operator's available Shared RAN(s).	[PR 5.7.6-002]

7.2.5 Regulatory Services p. 28

Table 7.2.5-1: Consolidated Requirements to the Regulatory Services

CPR #	Consolidated Potential Requirement	Original PR #	Comment
CPR 7.2.5-001	In case of Indirect Network Sharing and subject to regulatory requirements and mutual agreement between the participating operators and the hosting operator, the 5G system shall support regulatory services (e.g., PWS, emergency calls).	[PR 5.6.6-001] [PR 5.8.6-001]	PRs merged
CPR 7.2.5-002	In Indirect Network Sharing, the 5G system shall be able to provide a UE accessing a Shared NG-RAN network with positioning service in compliance with regulatory requirements.	[PR 5.6.6-002]	PR modified
CPR 7.2.5-003	Subject to regulatory requirements and mutual agreement between the participating operators and the hosting operator the Shared NG-RAN operator shall be able to broadcast PWS messages originated from the core network of the hosting operator.	[PR 5.8.6-002]	PR modified

7.2.6 Charging p. 28

Table 7.2.6-1: Charging requirements

CPR #	Consolidated Potential Requirement	Original PR #	Comment
CPR 7.2.6-001	The 5G core network shall be able to support collection of charging information associated with a UE accessing a Shared NG-RAN using Indirect Network Sharing.	[PR 5.2.6-001]	Align with the definitions. shared network → Shared NG-RAN

8 Conclusion and recommendations p. 28

This document analyzes a number of use cases to enhance the support of network sharing. Some considerations and the resulting potential consolidated requirements have been captured in clauses 6 and 7.

It is recommended to proceed with normative work and include the consolidated requirements identified in order to better serve communication services.