Content for TR 22.851 Word version: 19.1.0
5.2 Use Case on Service Continuity and QoS
5.2.1 Description
5.2.2 Pre-conditions
5.2.3 Service Flows
5.2.4 Post-conditions
5.2.5 Existing Features partly or fully covering Use Case Functionality
5.2.6 Potential New Requirements needed to support the Use Case
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5.2 Use Case on Service Continuity and QoS p. 11
5.2.1 Description p. 11
In Indirect Network Sharing scenario, the requirements to the services provided by the participating operator and the hosting operator for a UE moving between their service areas needs to be clearly defined. These service considerations are based on their user subscriptions and charging requirements from the participating operator. The service principle is not expected to be significantly different from the MOCN access sharing. The business here includes not only the operator's name displayed in the UE UI, but also the service logic provided by both the participating operator and the hosting operator for the services, such as voice, SMS and data communications for the UE.
5.2.2 Pre-conditions p. 11
Assumptions:
- OP 1 is a Hosting NG-RAN Operator.
- The core network of OP 2 does not have direct connection with OP1's Shared NG-RAN.
- There is connection between the OP1's CN and OP2's CN.
- UE 1 belongs to OP 1. UE 2 and UE N belong to OP 2.
5.2.3 Service Flows p. 11
Figure 5.2.3-1: Basic service scenario without direct connections between the Shared NG-RAN and the core networks of the participating operators
(⇒ copy of original 3GPP image)
(⇒ copy of original 3GPP image)
- UE 2 successfully registers to OP 2's PLMN via the Shared NG-RAN.
- UE 1 successfully registers to OP 1's PLMN.
- UE N successfully registers to OP 2's PLMN, via OP2's wireless access network.
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UE 2 initiates a service, for example a 5G voice call to user N, and succeeds under the shared network.
- OP 2 and OP1 do not need to expose the IMS network to each other, e.g., UE2 may also access services provided by their home environment in the same way even if the UE2 moves to the coverage of Shared NG-RAN of OP1, and it is not necessary to assume that the IMS network of OP1 is involved in this scenario.
- When UE 2 moves to OP 2's 4G area from the shared network, the call continues.
- When UE 2 moves to OP 2's 5G area from the shared network, the call does not drop.
- UE2 may also use other services under the shared network, just as it usually does in the OP2's network while OP1 and OP2 have different network services and service capabilities.
- The network sharing partners may set a specific sharing allocation model for a network sharing method communicating with. It is necessary to understand the number of the users, and how long users using a certain shared network method will take. The collection of charging information associated with the sharing method that the UE accesses with should be possible.
5.2.4 Post-conditions p. 12
The service of UE 2 succeeds, when UE 2 moves between shared access network and participating operator's network.
5.2.5 Existing Features partly or fully covering Use Case Functionality p. 12
SA1 has performed various studies on services aspects in previous releases. For the definition of service continuity and the description of user experience see TS 22.261. Requirements to service capabilities are described in TS 22.101 as follows:
The provision of services and service capabilities that is possible to offer in a network shall not be restricted by the existence of the network sharing It shall be possible for a core network operator to differentiate its service offering from other core network operators within the shared network.
It shall be possible to control the access to service capabilities offered by a shared network according to the core network operator the user is subscribed to.
The 3GPP System shall support service continuity for UEs that are moving between different Shared RANs or between a Shared RAN and a non-shared RAN.
Subscribers shall have a consistent user experience regardless of the domain used, subject to the constraints of the UE and access network.
Some 5G specific requirements are described in TS 22.261 as follows:
The 5G system shall support mobility procedures between a 5G core network and an EPC with minimum impact to the user experience (e.g. QoS, QoE).
The 5G system shall support inter- and/or intra- access technology mobility procedures within 5GS with minimum impact to the user experience (e.g. QoS, QoE).
In addition to the charging requirements of 5G system introduced in clause 9 of TS 22.261, the following requirement is defined in TS 22.101:
Charging and accounting solutions shall support the shared network architecture so that end users can be appropriately charged for their usage of the shared network, and network sharing partners can be allocated their share of the costs of the shared network resources.
Further charging requirements are specified in TS 29.513.
5.2.6 Potential New Requirements needed to support the Use Case p. 12
[PR 5.2.6-001]
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 5.2.6-002]
In case of Indirect Network Sharing and subject to Hosting and Participating Operators' policies, the 3GPP system shall support service continuity for UEs that are moving between different Shared NG-RANs or between a Shared NG-RAN and a non-shared RAN (managed by Hosting and Participating Operators).
[PR 5.2.6-003]
In case of Indirect Network Sharing and subject to Hosting and Participating Operators' policies, the 3GPP system shall be able to minimize the impact to the user experience (e.g., QoS, QoE) of UEs in an active communication moving between different Shared NG-RANs or between a Shared NG-RAN and a non-shared RAN (managed by Hosting and Participating Operators).
[PR 5.2.6-004]
In case of Indirect Network Sharing, the 5G system shall support a mechanism for a UE to access the subscribed PLMN services when entering a Shared NG-RAN.
