Principle Description
PLMN Sharing for Public and Enterprise Networks apply to the scenario where an eNodeB is connected to two core networks (CNs) sharing the same PLMN. One CN is on the enterprise network and the other is on the public network. Terminals served by the eNodeB connect to different CNs based on terminal types and number segments.
The PLMN Sharing for Public and Enterprise Networks require the support of CNs, eNodeBs, and terminals.
On the Network Side
When the S1 link is set up between the CN on the enterprise network and an eNodeB, the CN sends the virtual network operator (VNO) ID and the corresponding digit4 to the eNodeB. The eNodeB saves the VNO and digit4 information.
The eNodeB compares the virtual operation (VOP) information sent by a UE with the digit4. If the information matches, the UE is connected to the enterprise network.
If the CN is not configured with the digit4, or the VOP sent by the UE does not match the digit4, the eNodeB compares the VOP information with the VNO information. If the information matches, the UE is connected to the enterprise network. If the information does not match, the UE is connected to the public network.
If the CN is not configured with the VNO and the VOP of the UE does not match the digit4, the UE is connected to the public network.
If a UE does not carry the VOP information, the UE is directly connected to the public network.
NOTE:
In the current version, the network side supports only VNO number segments of three digits. If the accessed network for a UE is to be determined using the fourth digit, the digit4 needs to be configured.
On the Terminal Side
For a terminal of TTR3.0 or TTR4.0, the VOP number segment is the last seven digits of IMSI. When the terminal connects to the network, the VOP number segment is sent to the eNodeB. The eNodeB determines whether to connect the terminal to the public network CN or the enterprise network CN based on the first three digits of the VOP number segment. The following figure shows a VOP number segment.
For a terminal earlier than TTR3.0, when it connects to the network, no VOP number segment is sent to the eNodeB and the terminal is connected to the public network CN.
