Access method, apparatus, device, and system

1. An access method comprising:

receiving, by a selection function entity (SFE), a non-access stratum (NAS) request message from user equipment (UE) for requesting access, wherein the NAS request message comprises a usage type of the UE;

obtaining, by the SFE, the usage type of the UE from the NAS request message;

selecting, by the SFE based on the usage type of the UE, a service node in a network slice for the UE; and

directly sending the NAS request message to the service node.

2. The method according to claim 1 , further comprises:

receiving, by the RAN node, the NAS request message from the UE; and

sending, by the RAN node, the NAS request message from the UE to the SFE.

3. The method according to claim 1 , wherein the service node is available for providing a service associated with the usage type of the UE.

4. The method according to claim 1 , wherein the usage type comprises: mobile broadband, machine type communication or inter-vehicle communication.

5. An access method comprising:

receiving, by a selection function entity (SFE), a non-access stratum (NAS) request message from user equipment (UE) for requesting access via a radio access network node (RAN) node, wherein the NAS request message comprises a usage type of the UE;

determining, by the SFE, the usage type of the UE based on the NAS request message of the UE; and

selecting, by the SFE for the UE based on the usage type of the UE, a service node in a network slice and that can serve the UE, wherein the service node in the network slice is associated with the usage type of the UE;

wherein determining the usage type of the UE based on the NAS request message of the UE comprises:

obtaining, by the SFE, an ID of the UE;

sending, by the SFE, a subscriber data request to a home subscriber server (HSS), wherein the subscriber data request comprises the ID of the UE;

receiving, by the SFE, subscriber data of the UE returned by the HSS, wherein the subscriber data of the UE comprises the usage type of the UE; and

obtaining, by the SFE, the usage type of the UE from he subscriber data of the UE;

wherein obtaining the ID of the UE comprises:

(i) obtaining, by the SFE, the ID of the UE from the NAS request message; or

(ii) sending, by the SFE, an ID request to the UE, wherein the ID request is used to request the ID of the UE; and

receiving the ID of the UE returned by the UE; or

(iii) obtaining, by the SFE, a temporary ID of the UE in the NAS request message, wherein the temporary ID of the UE is allocated, to the UE, by a node in a source network slice in which the UE is located;

sending, by the SFE, a context request to the service node in the source network slice, wherein the context request comprises the temporary ID of the UE, and wherein the context request is used to request a context of the UE;

receiving, by the SFE, the context of the UE returned by the service node in the source network slice; and

obtaining, by the SFE, the ID of the UE from the context of the UE.

6. The method according to claim 5 , wherein after selecting, for the UE based on the usage type of the UE, the service node in the network slice and that can serve the UE, the method further comprises:

sending, by the SFE, a redirection message to the RAN node, wherein the redirection message comprises information about the service node in the network slice associated with the usage type of the UE and that is selected by the SFE for the UE, so that the RAN node sends the NAS request message to the service node in the network slice associated with the usage type of the UE.

7. The method according to claim 5 , wherein after selecting, for the UE based on the usage type of the UE, the service node in the network slice and that can serve the UE, the method further comprises:

directly sending, by the SFE, the NAS request message to the service node in the network slice associated with the usage type of the UE.

8. The method according to claim 5 , further comprising:

receiving, by the RAN node, a radio resource control (RRC) message for requesting access from the UE; and

sending, by the RAN node, the NAS request message to the SFE.

9. An apparatus comprising:

a processor;

a receiver in communication with the processor;

a sender in communication with the processor; and

the processor is configured to provide at least the following operations:

receiving, via the receiver, a non-access stratum (NAS) request message from user equipment (UE) for requesting access, wherein the NAS request message comprises a usage type of the UE;

obtaining the usage type of the UE from the NAS request message;

selecting, for the UE based on the usage type of the UE, a service node in a network slice; and

directly sending, using the sender, the NAS request message to the service node.

10. The apparatus according to claim 9 , wherein the service node is available for providing a service associated with the usage type of the UE.

11. The apparatus according to claim 9 , wherein the usage type comprises mobile broadband, machine type communication or inter-vehicle communication.

12. An apparatus comprising:

a processor;

a receiver configured to cooperate with the processor to receive a non-access stratum (NAS) request message from user equipment (UE) for requesting access via a radio access network node RAN node, wherein the NAS request message comprises a usage type of the UE; and

the processor is configured to:

determine the usage type of the UE based on the quest message of the UE; and

select, for the UE based on the usage type of the UE, a service node that is in a network slice and that can serve the UE, wherein the service node that is in the network slice and that can serve the UE is associated with the usage type of the UE,

wherein in determining the usage type of the UE based on the NAS request message of the UE, the processor is further configured to obtain an ID of the UE;

send a subscriber data request to an wherein the subscriber data request comprises the ID of the UE, and wherein the subscriber data request is used to request subscriber data of the UE;

receive the subscriber data of the UE returned by the ENS; and

obtain the usage type of the UE from the subscriber data of the UE;

wherein in obtaining the ID of the UE, the processor is further configured to:

 (i) obtain the ID of the UE from the NAS request message; or

 send an ID request to the UE, wherein the ID request is used to request the ID of the UE; and

 receive the ID of the UE returned by the UE; or

 (iii) obtain a temporary ID of the UE in the NAS request message, wherein the temporary ID of the UE is allocated, to the UE, by a node in a source network slice in which the UE is located;

 send a context request to the service node in the source network slice, wherein the context request comprises the temporary ID of the UE, and the context request is used to request a context of the UE;

 receive the context of the UE returned by the service node in the source network slice; and

 obtain the ID of the UE from the context of the UE.

13. The apparatus according to claim 12 , wherein the apparatus further comprises:

a sender configured to cooperate with the processor to send a redirection message to the RAN node, wherein the redirection message comprises information about the service node in the network slice associated with the usage type of the UE and that is selected by the SFE for the UE, so that the RAN node sends the NAS request message to the service node in the network slice associated with the usage type of the UE.

14. The apparatus according to claim 12 , wherein the apparatus further comprises:

a sender configured to cooperate with the processor to directly send the NAS request message to the service node in the network slice associated with the usage type of the UE.

15. A system comprising:

a radio access network (RAN) node configured to:

receive, from user equipment (UE), a non-access stratum (NAS) request message for requesting access; and

send the NAS request message, from the UE. to a selection function entity (SFE), wherein the NAS request message comprises a usage type of the UE; and

the SFE is configured to:

receive the NAS request message from the RAN node;

obtain the usage type of the UE from the NAS request message;

select, based on the usage type of the UE, a service node in a network slice for the UE; and

directly send the NAS request message to the service node.

16. The system according to claim 15 , wherein the service node is available for providing a service associated with the usage type of the UE.

17. The system according to claim 15 , wherein the usage type comprises mobile broadband, machine type communication or inter-vehicle communication.