Data transmission method and data transmission apparatus

1. A data transmission method comprising:

obtaining, by an access management network element, information about a first connection status of a terminal device in a first network, wherein the first connection status of the terminal device comprises a deregistered state, a data transmission idle state, or a state wherein the terminal device is physically disconnected from an access network in the first network;

restricting, by the access management network element, a data transmission procedure of the terminal device in a second network based on the information about the first connection status of the terminal device in the first network; and

resuming, by the access management network element, the data transmission procedure of the terminal device in the second network when the first connection status of the terminal device in the first network changes to a second connection status, wherein the second connection status of the terminal device in the first network comprises a registered state or a data transmission connected state.

2. The method according to claim 1 , wherein

the restricting, by the access management network element, a data transmission procedure of the terminal device in a second network based on the information about the first connection status of the terminal device in the first network, comprises:

when a duration of the first connection status of the terminal device in the first network exceeds a specified duration, restricting, by the access management network element, the data transmission procedure of the terminal device in the second network.

3. The method according to claim 1 , wherein the restricting, by the access management network element, the data transmission procedure of the terminal device in the second network comprises one of:

initiating, by the access management network element, a deregistration procedure of the terminal device in the second network; or

initiating, by the access management network element, a packet data unit (PDU) session release procedure of the terminal device in the second network; or

rejecting, by the access management network element, a registration procedure of the terminal device in the second network; or

rejecting, by the access management network element, a session establishment procedure of the terminal device in the second network; or

sending, by the access management network element, the information about the first connection status of the terminal device in the first network to a policy control network element, wherein the information about the first connection status is used by the policy control network element to initiate a PDU session release procedure of the terminal device in the second network; or

sending, by the access management network element, the information about the first connection status of the terminal device in the first network to a policy control network element, wherein the information about the first connection status is used by the policy control network element to reject a session establishment procedure of the terminal device in the second network; or

sending, by the access management network element, the information about the first connection status of the terminal device in the first network to a data management network element, wherein the information about the first connection status is used by the data management network element to perform a deregistration procedure of the terminal device in the second network; or

sending, by the access management network element, the information about the first connection status of the terminal device in the first network to a session management network element accessed by the terminal device in the second network, wherein the information about the first connection status is used by the session management network element to initiate a PDU session release procedure of the terminal device in the second network.

4. The method according to claim 1 , wherein the method further comprises:

sending, by the access management network element, reason information to the terminal device, wherein the reason information notifies the terminal device of a reason why the data transmission procedure of the terminal device in the second network is restricted.

5. The method according to claim 1 , wherein the second connection status of the terminal device in the first network comprises a state wherein the terminal device is physically connected to an access network.

6. The method according to claim 5 , wherein resuming, by the access management network element, the data transmission procedure of the terminal device in the second network, comprises:

when a duration of the connection status of the terminal device in the first network exceeds a specified duration, resuming, by the access management network element, the data transmission procedure of the terminal device in the second network.

7. The method according to claim 5 , wherein the resuming, by the access management network element, the data transmission procedure of the terminal device in the second network comprises:

sending, by the access management network element, indication information to a user plane data processing network element accessed by the terminal device in the second network, wherein the indication information indicates the user plane data processing network element to send user plane data that is from the terminal device or that is to be sent to the terminal device.

8. The method according to claim 5 , wherein the resuming, by the access management network element, the data transmission procedure of the terminal device in the second network, comprises:

initiating, by the access management network element, a PDU session modification procedure of the terminal device in the second network.

9. The method according to claim 5 , wherein the resuming, by the access management network element, the data transmission procedure of the terminal device in the second network, comprises: performing, by the access management network element, a registration procedure of the terminal device in the second network; or

performing, by the access management network element, a session establishment procedure of the terminal device in the second network; or

sending, by the access management network element, the information about the second connection status of the terminal device in the first network to a data management network element, wherein the information about the second connection status is used by the data management network element to perform a registration procedure of the terminal device in the second network.

10. The method according to claim 1 , wherein the obtaining, by an access management network element, information about a connection status of a terminal device in a first network comprises:

obtaining, by the access management network element, the information about the first connection status of the terminal device in the first network according to a heartbeat mechanism; or

receiving, by the access management network element, a message from the following network element accessed by the terminal device in the first network: an access network element, an access management network element, the terminal device, or a user plane function network element, wherein the message comprises the information about the first connection status of the terminal device in the first network.

11. The method according to claim 1 , wherein the first connection status of the terminal device in the first network and the second connection status of the terminal device in the first network is a connection status of a wireline connection in the first network.

12. The method according to claim 1 , wherein the data transmission procedure of the terminal device in the second network is wireless data transmission procedure of the terminal device in the second network.

13. An apparatus comprising:

at least one processor coupled with a memory, wherein the at least one processor is configured to execute instructions stored in the memory, to cause the apparatus to perform the following operations:

obtaining information about a first connection status of a terminal device in a first network, wherein the first connection status of the terminal device comprises a deregistered state, a data transmission idle state, or a state wherein the terminal device is physically disconnected from an access network in the first network;

restricting a data transmission procedure of the terminal device in a second network based on the information about the first connection status of the terminal device in the first network; and

resuming the data transmission procedure of the terminal device in the second network when the first connection status of the terminal device in the first network changes to a second connection status, wherein the second connection status of the terminal device in the first network comprises a registered state or a data transmission connected state.

14. The apparatus according to claim 13 , wherein

the restricting the data transmission procedure of the terminal device in the second network, comprises:

restricting the data transmission procedure of the terminal device in the second network when a duration of the first connection status of the terminal device in the first network exceeds a specified duration.

15. The apparatus according to claim 13 , wherein the restricting the data transmission procedure of the terminal device in the second network comprises one of:

initiating a deregistration procedure of the terminal device in the second network; or

initiating a packet data unit (PDU) session release procedure of the terminal device in the second network; or

rejecting a registration procedure of the terminal device in the second network; or

rejecting a session establishment procedure of the terminal device in the second network; or

sending the information about the first connection status of the terminal device in the first network to a policy control network element, wherein the information about the first connection status is used by the policy control network element to initiate a PDU session release procedure of the terminal device in the second network; or

sending the information about the first connection status of the terminal device in the first network to a policy control network element, wherein the information about the first connection status is used by the policy control network element to reject a session establishment procedure of the terminal device in the second network; or

sending the information about the first connection status of the terminal device in the first network to a data management network element, wherein the information about the first connection status is used by the data management network element to perform a deregistration procedure of the terminal device in the second network; or

sending the information about the first connection status of the terminal device in the first network to a session management network element accessed by the terminal device in the second network, wherein the information about the first connection status is used by the session management network element to initiate a PDU session release procedure of the terminal device in the second network.

16. The apparatus according to claim 13 , wherein the at least one processor is further configured to execute instructions stored in the memory, to cause the apparatus to perform the following operations:

sending reason information to the terminal device, wherein the reason information notifies the terminal device of a reason why the data transmission procedure of the terminal device in the second network is restricted.

17. The apparatus according to claim 13 , wherein the second connection status of the terminal device in the first network comprises a state wherein the terminal device is physically connected to an access network.

18. The apparatus according to claim 17 , wherein the resuming the data transmission procedure of the terminal device in the second network comprises:

sending indication information to a user plane data processing network element accessed by the terminal device in the second network, wherein the indication information indicates the user plane data processing network element to send user plane data that is from the terminal device or that is to be sent to the terminal device.

19. The apparatus according to claim 17 , wherein the resuming the data transmission procedure of the terminal device in the second network, comprises:

initiating a PDU session modification procedure of the terminal device in the second network.

20. A system comprising:

an access management network element; and

an access network element connected with the access management network element, wherein the access management network element comprises at least one processor coupled with a memory, wherein the at least one processor is configured to execute instructions stored in the memory, to cause the access management network element to perform the following operations:

obtaining information about a first connection status of a terminal device in a first network, wherein the first connection status of the terminal device comprises a deregistered state, a data transmission idle state, or a state wherein the terminal device is physically disconnected from an access network in the first network;

restricting a data transmission procedure of the terminal device in a second network based on the information about the first connection status of the terminal device in the first network; and

resuming, the data transmission procedure of the terminal device in the second network when the first connection status of the terminal device in the first network changes to a second connection status, wherein the second connection status of the terminal device in the first network comprises a registered state or a data transmission connected state.