Location area management method, control plane node, and user equipment

1. A location area management method, the method applied to a communications system, the communications system comprising a control plane node, the control plane node stores an upper-level area identity list of user equipment (UE), the method comprising:

determining, by the control plane node, a lower-level area identity list of the UE based on the upper-level area identity list;

sending, by the control plane node, the lower-level area identity list to the UE;

when the UE enters an idle state from a connected state, starting, by the control plane node, N reachability management timers, wherein N is equal to a quantity of levels of an area identity list of the UE stored on the control plane node; and

determining, by the control plane node, a paging range of the UE or a reachability status of the UE based on statuses of the N reachability management timers.

2. The method according to claim 1 , wherein an area corresponding to the lower-level area identity list is comprised in an area corresponding to the upper-level area identity list.

3. The method according to claim 1 , wherein the determining, by the control plane node, of a lower-level area identity list of the UE based on the upper-level area identity list comprises:

determining, by the control plane node, the lower-level area identity list of the UE based on the upper-level area identity list and at least one of a historical moving track of the UE, a moving mode of the UE, a predicted moving track of the UE, or a current location of the UE.

4. The method according to claim 1 , further comprising:

when the UE initiates initial registration or the UE is located in an area outside a registered location area, determining, by the control plane node, an initial-level area identity list of the UE; and

sending, by the control plane node, the initial-level area identity list to the UE, wherein

the area corresponding to the upper-level area identity list is comprised in an area corresponding to the initial-level area identity list, or the upper-level area identity list is the initial-level area identity list.

5. The method according to claim 1 , wherein the control plane node further stores a periodic location update time value of the upper-level area identity list, and the method further comprises:

sending, by the control plane node, a periodic location update time value of the lower-level area identity list to the UE, wherein

the periodic location update time value of the lower-level area identity list is greater than the periodic location update time value of the upper-level area identity list.

6. A location area management method, the method applied to a communications system, the communications system comprises user equipment (UE), the UE stores an upper-level area identity list of the UE, the method comprising:

receiving, by the UE, a lower-level area identity list from a control plane node;

storing, by the UE, the lower-level area identity list;

when the UE enters an idle state from a connected state, starting, by the UE, N periodic timers, wherein N is equal to a quantity of levels of an area identity list stored on the UE; and

determining, by the UE based on statuses of the N timers and a location of the UE, to send a location area management request to the control plane node, wherein the location area management request is used to notify the control plane node that the UE is in a reachable state.

7. The method according to claim 6 , wherein an area corresponding to the lower-level area identity list is comprised in an area corresponding to the upper-level area identity list.

8. The method according to claim 6 , further comprising:

storing, by the UE, the lower-level area identity list according to an instruction of the control plane node; or

determining, by the UE, a level of the lower-level area identity list according to an instruction of the control plane node.

9. The method according to claim 6 , further comprising:

receiving, by the UE, an initial-level area identity list from the control plane node; and

storing, by the UE, the initial-level area identity list, wherein

the area corresponding to the upper-level area identity list is comprised in an area corresponding to the initial-level area identity list, or the upper-level area identity list is the initial-level area identity list.

10. The method according to claim 6 , wherein the UE further stores a periodic location update time value of the upper-level area identity list, and the method further comprises:

receiving, by the UE, a periodic location update time value of the lower-level area identity list, wherein

the periodic location update time value of the lower-level area identity list is greater than the periodic location update time value of the upper-level area identity list.

11. An apparatus, wherein the apparatus stores an upper-level area identity list of user equipment (UE), and the apparatus comprises at least one processor coupled with a non-transitory storage medium storing executable instructions; wherein the executable instructions, when executed by the at least one processor, cause the at least one processor to:

receive a lower-level area identity list from a control plane node; and

store the lower-level area identity list;

when the UE enters an idle state from a connected state, start N periodic timers, wherein N is equal to a quantity of levels of an area identity list stored on the apparatus; and

determine, based on statuses of the N timers and a location of the UE, to send a location area management request to the control plane node, wherein the location area management request is used to notify the control plane node that the UE is in a reachable state.

12. The apparatus according to claim 11 , wherein an area corresponding to the lower-level area identity list is comprised in an area corresponding to the upper-level area identity list.

13. The apparatus according to claim 11 , wherein the at least one processor is configured to:

store the lower-level area identity list according to an instruction of the control plane node; or

determine a level of the lower-level area identity list according to an instruction of the control plane node.

14. The apparatus according to claim 13 , wherein the at least one processor is further configured to:

receive indication information from the control plane node, wherein the indication information is used to instruct the apparatus to store the lower-level area identity list, and the indication information is further used to instruct the apparatus to retain the stored area identity list; and

store the lower-level area identity list based on the indication information.

15. The apparatus according to claim 13 , wherein the at least one processor is further configured to:

receive indication information from the control plane node, wherein the indication information is used to indicate the level of the lower-level area identity list to the apparatus; and

store the level of the lower-level area identity list based on the indication information.

16. The apparatus according to claim 11 , wherein the at least one processor is further configured to:

receive an initial-level area identity list from the control plane node; and

store the initial-level area identity list, wherein the area corresponding to the upper-level area identity list is comprised in an area corresponding to the initial-level area identity list, or the upper-level area identity list is the initial-level area identity list.

17. The apparatus according to claim 11 , wherein the apparatus further stores a periodic location update time value of the upper-level area identity list, and the at least one processor is further configured to receive a periodic location update time value of the lower-level area identity list, wherein

the periodic location update time value of the lower-level area identity list is greater than the periodic location update time value of the upper-level area identity list.