Filtered authorization list for private networks

1. A method, comprising:

receiving, at a next generation radio access network (NG-RAN) node of a registration area, a list of cells and their associated tracking area identities (TAIs) from a second NG-RAN node of a second registration area;

determining, by the NG-RAN node, which cells of the received TAIs have cells neighbouring cells of the NG-RAN node;

based on determining which cells of the received TAIs have cells neighbouring cells of the NG-RAN node, determining, by the NG-RAN node, which of the received TAIs are neighbouring TAIs of a TAI of the NG-RAN node;

building, by the NG-RAN node, a list of neighbouring TAIs corresponding to the second NG-RAN node;

transmitting, by the NG-RAN node to an access management function, a list of closed access group identifiers (CAG IDs) supported by the TIA of the network node and the list of neighbouring TAIs corresponding to the second NG-RAN node; and

upon a user equipment connecting via the NG-RAN node, receiving, by the NG-RAN node from the access management function, a list of user equipment allowed CAG IDs within a mobility restriction list information element contained in a next generation application protocol initial context setup request message;

storing, by the NG-RAN node, the list of user equipment allowed CAG ID;

using, by the NG-RAN node, the list of user equipment allowed CAG ID for connected mode mobility; and

creating an initial context setup for the user equipment in the NG-RAN node.

2. The method of claim 1 , wherein the user equipment uses the list of user equipment allowed CAG ID for idle mode mobility.

3. The method of claim 1 , wherein the receiving of the list of cells comprises receiving the list in an Xn setup message from the second NG-RAN node.

4. The method of claim 1 , further comprising transmitting the list of user equipment allowed CAG IDs to the user equipment.

5. The method of claim 3 , wherein the mobility restriction list IE is contained in an initial context setup request message.

6. The method of claim 1 , wherein the receiving of the list of user equipment allowed CAG IDs comprises receiving of the list of user equipment allowed CAG IDs when a user equipment connects via the NG-RAN node of its registration area.

7. The method of claim 1 , further comprising: storing the received list of user equipment allowed CAG IDs and using it for connected mode mobility.

8. A next generation radio access network (NG-RAN) node of a first registration area, the NG-RAN node comprising:

at least one processor; and

at least one non-transitory memory including computer program code, the at least one non-transitory memory and the computer program code configured to, with the at least one processor, cause the NG-RAN node at least to:

receive a list of cells and their associated tracking area identities (TAIs) from a second NG-RAN of a second registration area;

determine which cells of the received TAIs have cells neighbouring cells of the apparatus;

based on determining which cells of the received TAIs have cells neighbouring cells of the apparatus, determine which of the received TAIs are neighbouring TAIs of a TAI of the apparatus;

build a list of neighbouring TAIs corresponding to the second apparatus;

transmit, to an access management function, a list of closed access group identifiers (CAG IDs) supported by the TIA of the NG-RAN node and the list of neighbouring TAIs corresponding to the second apparatus; and

upon a user equipment connecting via the NG-RAN node, receive, from the access management function, a list of user equipment allowed CAG IDs within a mobility restriction list information element contained in a next generation application protocol initial context setup request message;

store the list of user equipment allowed CAG ID;

use the list of user equipment allowed CAG ID for connected mode mobility; and

enabling an initial context setup for the user equipment to be created in the NG-RAN node.

9. The NG-RAN of claim 8 , wherein the user equipment uses the list of user equipment allowed CAG ID for idle mode mobility.

10. The NG-RAN of claim 8 , wherein the receiving of the list of cells comprises receiving the list in an Xn setup message from the second network node.

11. The NG-RAN of claim 8 , wherein the NG-RAN is further caused to transmit the list of user equipment allowed CAG IDs to the user equipment.

12. The apparatus of claim 11 , wherein the mobility restriction list IE is contained in an initial context setup request message.

13. The NG-RAN of claim 8 , wherein the receiving of the list of user equipment allowed CAG IDs comprises receiving of the list of user equipment allowed CAG IDs when a user equipment connects via the NG-RAN of its registration area.

14. The NG-RAN of claim 8 , the NG-RAN is further caused to store the received list of user equipment allowed CAG IDs and use it for connected mode mobility.

15. A system comprising:

a next generation radio access network (NG-RAN) of a first registration area, the NG-RAN comprising:

a processor; and

a non-transitory computer-readable memory comprising computer-executable instructions that, when executed by the processor, cause the processor to perform the following operations:

receive a list of cells and their associated tracking area identities (TAIs) from a second NG-RAN of a second registration area;

determine which cells of the received TAIs have cells neighbouring cells of the NG-RAN;

based on determining which cells of the received TAIs have cells neighbouring cells of the NG-RAN, determine which of the received TAIs are neighbouring TAIs of a TAI of the NG-RAN;

build a list of neighbouring TAIs corresponding to the second NG-RAN;

transmit, to an access management function, a list of closed access group identifiers (CAG IDs) supported by the TIA of the network node and the list of neighbouring TAIs corresponding to the second NG-RAN; and

upon a user equipment connecting via the NG-RAN node, receive, from the access management function, a list of user equipment allowed CAG IDs within a mobility restriction list information element contained in a next generation application protocol initial context setup request message;

store the list of user equipment allowed CAG ID;

use the list of user equipment allowed CAG ID for connected mode mobility; and

enable an initial context setup for the user equipment to be created in the NG-RAN node.

16. The system of claim 1 , wherein the user equipment uses the list of user equipment allowed CAG ID for idle mode mobility.

17. The system of claim 16 , wherein the receiving of the list of cells comprises receiving the list in an Xn setup message from the second network node.

18. The system of claim 17 , wherein the computer-executable instructions further cause the processor to transmit the list of user equipment allowed CAG IDs to the user equipment.

19. The system of claim 18 , wherein the mobility restriction list IE is contained in an initial context setup request message.

20. The system of claim 19 , wherein receiving of the list of user equipment allowed CAG IDs comprises receiving of the list of user equipment allowed CAG IDs when a user equipment connects via the NG-RAN of its registration area.