AMF selection for isolated network slice

1. A method comprising:

receiving, by a radio access network from a wireless device, a first registration request;

sending, by the radio access network to a network repository function and in response to receiving the first registration request, a first message comprising:

at least one single network slice selection assistance information (S-NSSAI) of at least one network slice; and

network slice isolation information for the at least one S-NSSAI, wherein the network slice isolation information indicates that one or more first network functions of the at least one S-NSSAI are requested to be isolated from one or more second network functions of one or more other network slices;

receiving, by the radio access network from the network repository function, a second message based on the first message, wherein the second message comprises an Internet protocol address of an access and mobility management function; and

sending, by the radio access network to the access and mobility management function, a second registration request for the first registration request.

2. The method of claim 1 , wherein the first message comprises at least one of:

a user identity of the wireless device; or

at least one data network name.

3. The method of claim 1 , wherein the network slice isolation information further indicates that a network slice of the at least one network slice is isolated from one or more other network slices.

4. The method of claim 1 , wherein the network slice isolation information comprises a network slice instance identifier of the network slice.

5. The method of claim 1 , wherein the network slice is isolated from one or more other network slices, when the network slice is fully isolated or partly isolated from the one or more other network slices.

6. The method of claim 1 , wherein the network slice is isolated from one or more other network slices, when the network slice is logically isolated or physically isolated from the one or more other network slices.

7. The method of claim 1 , wherein the at least one S-NSSAI is one of a requested S-NSSAI, a subscription S-NSSAI, or allowed S-NSSAI.

8. The method of claim 1 , wherein the selecting the access and mobility management function is further based on at least one of:

the at least one S-NSSAI;

at least one data network name; or

a user identity.

9. The method of claim 1 , wherein the second message comprises an Internet protocol address of the access and mobility management function.

10. The method of claim 1 , wherein the network slice isolation information comprises a network slice isolation level to indicate a level at which the at least one network slice is isolated from one or more other network slices.

11. The method of claim 10 , wherein the level at which the at least one network slice is isolated from the one or more other network slices comprises a fully isolated network slice.

12. The method of claim 11 , wherein the fully isolated network slice is network slice instance does not share neither the radio access network nor a core network function with any other network slice instance.

13. The method of claim 10 , wherein the level at which the at least one network slice is isolated from the one or more other network slices comprises a partly isolated network slice with sharing of the radio access network.

14. The method of claim 13 , wherein the partly isolated network slice with radio access network shared is the radio access network belonging to an isolated network slice instance is a network function that can be seen from outside of the isolated network slice instance.

15. The method of claim 10 , wherein the level of the at least one network slice is isolated from one or more other network slices comprises a partly isolated network slice with radio access network and access and mobility management function shared.

16. The method of claim 15 , wherein the partly isolated network slice with radio access network and access and mobility management function shared is both the radio access network and access and mobility management function belonging to an isolated network slice instance that can be seen from the outside of the isolated network slice instance.

17. The method of claim 1 , further comprising sending, by the network repository function to a unified data management, a third message requesting subscription information of the wireless device, wherein the third message comprising user identity and a requested S-NSSAI.

18. The method of claim 17 , further comprising receiving, by the network repository function from the unified data management, a fourth message in response to the third message, wherein the fourth message comprising user identity and a subscribed S-NSSAI.

19. The method of claim 18 , wherein the fourth message comprises a subscribed network slice isolation information applied to the subscribed S-NSSAI.

20. The method of claim 17 , wherein the third message comprises a requested network slice isolation information applied to the requested S-NSSAI.