Session establishment method and device

1. A session establishment method implemented via a terminal, the method comprising:

determining, by the terminal, that the terminal fails to receive broadcast data on a broadcast path;

sending, by the terminal, a broadcast quality report message, that includes a packet data unit (PDU) session establishment request message, to a session management function entity based on determining that the terminal fails to receive the broadcast data on the broadcast path, wherein

the PDU session establishment request message requests to establish a PDU session for the terminal,

the PDU session uses a unicast path, and

the broadcast quality report message carries broadcast received quality information indicating that the terminal fails to receive the broadcast data on the broadcast path;

receiving, by the terminal from the session management function entity, a response to the broadcast report quality message including information about a quality of service (QoS) flow corresponding to the PDU session and an identifier associated with the broadcast session; and

establishing, by the terminal, the PDU session with the session management function entity based on the information about the QoS flow and the identifier associated with the broadcast session included in the response, wherein

the response is used to ensure that a user data plane is consistent on the broadcast path and the unicast path when using the broadcast path and the unicast path, and

the terminal receives broadcast data transmitted via the PDU session.

2. The method according to claim 1 , wherein determining that the terminal fails to receive the broadcast data on the broadcast path comprises:

determining that a received quality of a broadcast channel signal of the terminal is less than a specified quality value.

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

determining that the terminal requires switching from the broadcast path to a unicast path, wherein

the PDU session establishment request message is sent based on determining that the terminal requires switching from the broadcast path to the unicast path.

4. The method according to claim 1 , wherein the session management function entity directly establishes the PDU session with the terminal based on the broadcast quality report message.

5. The method according to claim 1 , wherein the broadcast quality report message is sent to an access and mobility management function entity, and the access and mobility management function entity sends the broadcast quality report message to the session management function entity.

6. The method according to claim 1 , wherein the QoS flow is associated with a forwarding and processing policy.

7. The method according to claim 6 , wherein the forwarding and processing policy includes any one of: a schedule policy, a queue management policy, a data shaping policy, and a radio link control (RLC) configuration policy.

8. A session establishment method implemented via a session management function entity, the method comprising:

receiving, by the session management function entity, a broadcast quality report message, that includes a packet data unit (PDU) session establishment request message, from a terminal in association with a determination that the terminal fails to receive broadcast data on a broadcast path, wherein

the PDU session establishment request message requests to establish a PDU session for the terminal,

the PDU session uses a unicast path,

the broadcast quality report message carries broadcast received quality information indicating that the terminal fails to receive the broadcast data on the broadcast path;

sending, by the session management function entity to the terminal, a response to the broadcast report quality message including information about a quality of service (QoS) flow corresponding to the PDU session and an identifier associated with the broadcast session; and

establishing, by the session management function entity, the PDU session with the terminal based on the information about the QoS flow and the identifier associated with the broadcast session included in the response, wherein

the response is used to ensure that a user data plane is consistent on the broadcast path and the unicast path when using the broadcast path and the unicast path, and

the terminal receives broadcast data transmitted via the PDU session.

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

sending a PDU session establishment response message to the terminal.

10. An apparatus, comprising:

a processor; and

a memory configured to store computer readable instructions that, when executed by the processor, cause the apparatus to:

determine that a terminal fails to receive broadcast data on a broadcast path;

send a broadcast quality report message, that includes a packet data unit (PDU) session establishment request message, to a session management function entity based on determining that the terminal fails to receive the broadcast data on the broadcast path, wherein

the PDU session establishment request message requests to establish a PDU session for the terminal,

the PDU session uses a unicast path, and

the broadcast quality report message carries broadcast received quality information indicating that the terminal fails to receive the broadcast data on the broadcast path;

receive, from the session management function entity, a response to the broadcast report quality message including information about a quality of service (QoS) flow corresponding to the PDU session and an identifier associated with the broadcast session; and

establish the PDU session with the session management function entity based on the information about the QoS flow and the identifier associated with the broadcast session included in the response, wherein

the response is used to ensure that a user data plane is consistent on the broadcast path and the unicast path when using the broadcast path and the unicast path, and

the terminal receives broadcast data transmitted via the PDU session.

11. The apparatus according to claim 10 , wherein the apparatus is further caused to:

determine that a received quality of a broadcast channel signal of the terminal is less than a specified quality value.

12. The apparatus according to claim 10 , wherein the apparatus is further caused to:

determine that the terminal requires switching from the broadcast path to a unicast path, wherein

the PDU session establishment request message is sent based on determining that the terminal requires switching from the broadcast path to the unicast path.

13. An apparatus, comprising:

a processor; and

a memory configured to store computer readable instructions that, when executed by the processor, cause the apparatus to:

receive a broadcast quality report message, that includes a packet data unit (PDU) session establishment request message, from a terminal in association with a determination that the terminal fails to receive broadcast data on a broadcast path, wherein

the PDU session establishment request message requests to establish a PDU session for the terminal,

the PDU session uses a unicast path, and

the broadcast quality report message carries broadcast received quality information indicating that the terminal fails to receive the broadcast data on the broadcast path;

send, to the terminal, a response to the broadcast report quality message including information about a quality of service (QoS) flow corresponding to the PDU session and an identifier associated with the broadcast session; and

establish the PDU session with the terminal based on the information about the QoS flow and the identifier associated with the broadcast session included in the response, wherein

the response is used to ensure that a user data plane is consistent on the broadcast path and the unicast path when using the broadcast path and the unicast path, and

the terminal receives broadcast data transmitted via the PDU session.

14. The apparatus according to claim 13 , wherein the apparatus is further caused to:

send a PDU session establishment response message to the terminal.