Content for TR 22.851 Word version: 19.1.0
5.4 Use Case on International Roaming Users in a Shared Network
5.4.1 Description
5.4.2 Pre-conditions
5.4.3 Service Flows
5.4.4 Post-conditions
5.4.5 Existing Features partly or fully covering Use Case Functionality
5.4.6 Potential New Requirements needed to support the Use Case
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5.4 Use Case on International Roaming Users in a Shared Network p. 16
5.4.1 Description p. 16
There are network sharing scenarios in the process of 5G deployment due to different operators' business consideration, such as network planning, operation and other factors, which introduce demand for 5G network sharing with indirect connection between the shared access network and a participating operator's core network, especially in countries with a wide range of rural areas, where seamless 5G radio coverage is hard to achieve. Benefit from 5G network sharing technology, an operator can not only save investment for 5G deployment, but also expand 5G coverage in vaster area as well. However, in this case, it is also required to allow inbound international roaming subscribers to use the shared resources of a hosting operator. Therefore, it is suggested investigating how to realize the scenario in this situation.
5.4.2 Pre-conditions p. 16
In the 5G scenario, an operator may deploy its network as an applicable shared network to other operators.
As illustrated in Figure 5.4.2-1, three operators (OP1, OP2, OP3) are involved:
- OP1, as a Hosting NG-RAN Operator, owns an applicable Shared NG-RAN which can be shared to other operators (e.g., OP2).
- OP2, as a Participating NG-RAN Operator, has 5G network sharing agreement with OP1. In addition, OP2 may have its own non-shared 5G network.
- Shared NG-RAN of OP1 does not have direct connections between the shared access and the core networks of the participating operators OP2.
- OP3 is a roaming partner of OP2, but has no roaming agreement with OP1.
- UE subscribes to OP3's network as a foreign operator's network.
Figure 5.4.2-1: Scenario of International Roaming Users in a Shared Network
(⇒ copy of original 3GPP image)
(⇒ copy of original 3GPP image)
5.4.3 Service Flows p. 16
When a UE of OP3 travels to the coverage of OP2's NG-RAN, it can enjoy services provided by their home environment in another country via OP2's network.
When a UE of OP3 travels to the coverage of OP1's shared NG-RAN, it can enjoy services provided by their home environment in another country via OP1's shared access network and OP2's network.
5.4.4 Post-conditions p. 17
It is the same for the service experience and treatment of OP2's UE and OP3's UE in the coverage of OP1's Shared NG-RAN, based on the agreement between operators.
5.4.5 Existing Features partly or fully covering Use Case Functionality p. 17
3GPP TS 22.011 introduces requirements on roaming in shared networks, as described below:
The following requirements are applicable to GERAN, UTRAN, E-UTRAN and NG-RAN sharing scenarios:
Other roaming related requirements are described in TS 22.101:
- When network sharing exists between different operators and a user roams into the shared network it shall be possible for that user to register with a core network operator (among the network sharing partners) that the user's home operator has a roaming agreement with, even if the operator is not operating a radio access network in that area.
3GPP specifications should be in compliance with the following objectives:
e)
to provide support of roaming users by enabling users to access services provided by their home environment in the same way even when roaming.
5.4.6 Potential New Requirements needed to support the Use Case p. 17
[PR 5.4.6-001]
The 5G system shall enable Shared NG-RAN of a Hosting Operator with the indirect connection between Shared NG-RAN and a Participating NG-RAN Operator's core network to provide services for inbound roaming users.
