CN114339643A

CN114339643A - Method for providing policy rules and session management network element

Info

Publication number: CN114339643A
Application number: CN202011052641.3A
Authority: CN
Inventors: 周晓云; 吴义壮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2022-04-12
Anticipated expiration: 2040-09-29
Also published as: CN114339643B; WO2022068502A1

Abstract

The embodiment of the application discloses a method for providing a policy rule and a session management network element, which are used for acquiring the policy rule for detecting a UPF (unified Power flow) data packet when an SMF (Small message Filter) cannot directly interact with a PCF (PCF). The method in the embodiment of the application comprises the following steps: the first SMF sends data description information to a second SMF which can interact with the PCF, the second SMF obtains a corresponding PCC rule from the PCF according to the data description information, and then generates a corresponding policy rule to send to the first SMF, so that the first SMF can obtain the policy rule for UPF detection data packet according to the PCC rule.

Description

Method for providing policy rules and session management network element

Technical Field

The embodiment of the application relates to the field of communication, and in particular relates to a policy rule providing method and a session management network element.

Background

In 4G, 5G and future communication protocols, one of the functions of the Session Management Function (SMF) is to separate the user plane and the control plane and take charge of the function of the control plane, that is, to provide policy rules for the User Plane Function (UPF).

When an application needs to subscribe to an event, the event is related to data transmitted by the application and the UE, and a UPF is needed to detect a data packet transmitted by the UE (for example, if the subscribed event is a data packet is cached, the UPF needs to cache the data packet and report the event that the data packet is cached), the SMF needs to request a Policy Control and Charging (PCC) rule from a PCF, a policy rule for detecting the state of the data packet is generated according to the PCC rule, and the UPF realizes detection and event reporting of the corresponding data packet according to the policy rule, so as to realize event reporting of the event subscription.

When the SMF and the PCF cannot interact directly, the SMF cannot acquire the PCC rule, and the SMF cannot correctly formulate a policy rule for UPF detection of the data packet. For example, in a roaming scenario or in a scenario where an intermediate-session management function (I-SMF) exists, since the visited-session management function (V-SMF, visited-SMF) and the I-SMF cannot directly interact with the PCF, the PCC rule cannot be obtained, and the V-SMF and the I-SMF cannot correctly formulate a policy rule for detecting a packet by using the UPF.

Disclosure of Invention

The embodiment of the application provides a method for providing a policy rule, which is used for acquiring a PCC rule when an SMF (Small message Filter) cannot directly interact with a PCF (PCF), so as to acquire the policy rule for detecting a data packet by a UPF (user equipment).

A first aspect of an embodiment of the present application provides a method for providing a policy rule, where the method includes:

after the UE accesses the network and establishes a PDU session, the application may request to create a subscription for a first event, where the first event relates to data transmitted by the application and the UE and requires the UPF to detect a data packet transmitted by the UE, where the data packet may include data received by the UE.

When an application requests to subscribe to a first event, a first session management network element SMF may receive a first message, where the first message is used to request to create a subscription for the first event, and the first message may include first description information of data, where the data is data received by a UE, and in this embodiment of the present application, the first description information may also be referred to as first data description information;

the first SMF may send a second message to the second session management network element SMF according to the request policy indication information, where the request policy indication information is used to indicate the first SMF to acquire the policy rule corresponding to the subscription event from the PCF, and the second message includes the first description information and is used to request the first policy rule corresponding to the first description information;

the first SMF receives a first policy rule sent by the second SMF;

the first SMF determines a second policy rule according to the first policy rule;

and the first SMF sends a second policy rule to a user plane function network element UPF so that the UPF processes the data.

In the embodiment of the application, a first SMF which cannot directly interact with a PCF sends first description information to a second SMF which can directly interact with the PCF, and receives a first policy rule generated by the second SMF according to the first description information, so as to generate a corresponding policy rule. The first SMF completes the subscription of the event under the condition that the first SMF cannot be directly connected with the PCF.

With reference to the first aspect, in a first implementation manner of the first aspect of the present application, when updating the first event subscription, providing a corresponding policy rule:

specifically, the second message may further include a first identifier, where the first identifier is used to identify a transaction between the first SMF and the second SMF, the first identifier corresponds to a subscription of the first event, and the corresponding transaction and the corresponding policy rule may be determined according to the first identifier;

after the first SMF sends the first message to the second SMF, the method further comprises:

the first SMF receives a third message, where the third message is used to request to update the subscription of the first event, and the third message includes second description information of the data, and in this embodiment, the second description information may also be referred to as second data description information;

the first SMF sends a fourth message to the second SMF, wherein the fourth message is used for requesting the second SMF to update the first policy rule, and the fourth message comprises a first identifier and second description information;

the first SMF receives a fourth policy rule sent by the second SMF, wherein the fourth policy rule is obtained by updating the first policy rule according to the second description information;

and the first SMF updates the second policy rule according to the fourth policy rule, and obtains the policy rule corresponding to the second description information at the first SMF.

In this embodiment of the application, the first SMF sends the second description information and the first identifier to the second SMF, so that the second SMF updates the first policy rule according to the second description information to obtain a fourth policy rule, and receives the fourth policy rule sent by the second SMF, thereby generating the policy rule corresponding to the second description information. And updating the event subscription after the event subscription is completed.

With reference to the first implementation manner of the first aspect, in a second implementation manner of the first aspect of this embodiment of the present application, after the first SMF sends the fourth message to the second SMF, the method further includes:

the first SMF receives a tenth message, where the tenth message is used to request to update the subscription of the first event, and the tenth message includes third description information of the data, and in this embodiment of the present application, the third description information may also be referred to as third data description information;

the first SMF sends an eleventh message to the second SMF, wherein the eleventh message is used for requesting the second SMF to update the fourth policy rule, and the eleventh message comprises the first identifier and the third description information;

the first SMF receives a sixth policy rule sent by the second SMF, wherein the sixth policy rule is obtained by updating the fourth policy rule according to the third description information;

and the first SMF updates the policy rule related to the first event at the first SMF according to the sixth policy rule, and obtains the policy rule corresponding to the third description information at the first SMF.

In this embodiment of the application, the first SMF sends third description information and the first identifier to the second SMF, so that the second SMF updates the fourth policy rule according to the third description information to obtain a sixth policy rule, and receives the sixth policy rule sent by the second SMF, thereby generating the policy rule corresponding to the third description information. Updating of the event subscription again is achieved after updating of the event subscription.

With reference to the first aspect, in a third implementation manner of the first aspect of the embodiment of the present application, deletion of the subscription to the first event may also be implemented:

specifically, the first message may further include a first identifier, where the first identifier is used to identify a transaction between the first SMF and the second SMF, and may determine a corresponding transaction and a corresponding policy rule according to the first identifier;

specifically, in this embodiment, the first flag may represent the first event between the first SMF and the second SMF;

the first SMF receives a fifth message, wherein the fifth message is used for requesting to delete the subscription of the first event;

and the first SMF sends a sixth message to the second SMF, wherein the sixth message is used for requesting to delete the first policy rule and comprises the first identifier and a deletion indication.

In this embodiment of the application, the first SMF sends the deletion instruction and the first identifier to the second SMF, so that the second SMF deletes the first policy rule according to the deletion instruction. And deleting the event subscription after the event subscription is finished.

With reference to the first implementation manner of the first aspect, in a fourth implementation manner of the first aspect of the embodiment of the present application, deletion of an updated subscription to the first event may also be implemented:

specifically, after the first SMF sends the fourth message to the second SMF, the method further includes:

the first SMF receives a twelfth message, wherein the twelfth message is used for requesting to delete the subscription of the first event;

the first SMF sends a thirteenth message to the second SMF, the thirteenth message requesting deletion of the fourth policy rule, the thirteenth message comprising the first identity and a deletion indication.

In this embodiment of the application, the first SMF sends the deletion instruction and the first identifier to the second SMF, so that the second SMF deletes the fourth policy rule according to the deletion instruction. Deletion of updated event subscriptions is achieved.

With reference to the first aspect, any one of the first embodiment of the first aspect to the fourth embodiment of the first aspect, in a fifth embodiment of the first aspect of the examples of the present application,

before the first SMF sends the second message to the second SMF according to the request policy indication information, the method further includes:

and the first SMF receives the request strategy indication information sent by the second SMF.

In this embodiment of the application, according to the request policy indication information, the first SMF may know that the policy indication information needs to be requested, thereby obtaining the policy rule corresponding to the first event subscription.

With reference to the first aspect, any one of the first implementation manner of the first aspect to the fifth implementation manner of the first aspect, in a sixth implementation manner of the first aspect of the examples of this application,

the request policy indication information includes at least one of indication information that policy charging control is applied to the UE, indication information that reports reception of a downlink data notification event subscription, or indication information that reports received data description information.

With reference to the first aspect, any one of the first implementation manner of the first aspect to the sixth implementation manner of the first aspect, in a seventh implementation manner of the first aspect of the examples of the present application,

event subscription type indication information is further included in the first message, and the event subscription type indication information is used for indicating the type of subscription of the first event.

In the embodiment of the application, according to the event subscription type indication information, the second SMF can determine the subscription type of the first event, and when requesting the PCC rule from the PCF, the corresponding downlink data notification event subscription trigger can be determined according to the indication information, and the corresponding trigger does not need to be determined through the event subscription, thereby saving the computational resources of the second SMF.

With reference to the seventh implementation manner of the first aspect, in an eighth implementation manner of the first aspect of the examples of the present application,

the first SMF receiving the first policy rule sent by the second SMF comprises the following steps:

the first SMF receives a first policy rule and notification control indication information sent by a second SMF, and the notification control indication information is determined according to the event subscription type indication information;

the first SMF determining the second policy rule according to the first policy rule comprises:

the first SMF determines a second policy rule according to the first policy rule and the notification control indication information.

In the embodiment of the application, the first SMF may determine the second policy rule directly according to the first policy rule and the notification control indication information, without determining a first event corresponding to the first policy rule, and then determine the second policy rule according to the first event, so that the operation resources and the time delay of the first SMF are saved, and the efficiency is improved.

With reference to the first aspect, any one of the first implementation manner of the first aspect to the seventh implementation manner of the first aspect, in a ninth implementation manner of the first aspect of the examples of the present application,

the first SMF determines a second policy rule based on the first policy rule and the subscription to the first event.

In the embodiment of the application, the first SMF determines the second policy rule according to the first policy rule and the subscription of the first event, and does not need to carry event subscription type indication information and notification control indication information in messages sent and received by the second SMF, thereby saving the operation resources and network bandwidth resources of network elements which need to send and receive and determine the two indication information in the network.

With reference to the first aspect, any one of the first implementation manner of the first aspect to the ninth implementation manner of the first aspect, in a tenth implementation manner of the first aspect of the examples of the present application,

after the first SMF sends the second policy rule to the UPF, the method further includes:

the first SMF receives a reported second event after the UPF processes the data;

the first SMF determines a first event based on the second event and reports the first event to an event receiving network element, the event receiving network element configured to receive a report related to the first event.

With reference to the tenth implementation manner of the first aspect, in the eleventh implementation manner of the first aspect of the examples of this application,

the second event includes an event that the data is buffered or an event that the data is lost.

With reference to the first aspect, any one of the first embodiment of the first aspect through the eleventh embodiment of the first aspect, in a twelfth embodiment of the first aspect of the examples of the present application,

the first event includes a downlink data notification failure event or a downlink data transmission status event.

With reference to the first aspect and any one of the first implementation manner of the first aspect to the twelfth implementation manner of the first aspect, in a thirteenth implementation manner of the first aspect of this embodiment of the present application, the first policy rule is the first N4 information.

With reference to the first aspect, or any one of the first implementation manner of the first aspect to the thirteenth implementation manner of the first aspect, in a fourteenth implementation manner of the first aspect of this embodiment of the present application, the second policy rule is second N4 information.

With reference to the eighth implementation manner of the first aspect, in a fifteenth implementation manner of the first aspect of the embodiment of the present application, the notification control indication information is included in the first policy rule.

In the embodiment of the present application, the notification control indication information is included in the first policy rule, and in the process of forwarding and determining the second policy rule according to the first policy rule, the notification control indication information is included in the first policy rule, so that the notification control indication information does not need to be processed separately, and the operation resource of the device is saved.

With reference to the first implementation manner of the first aspect, in a sixteenth implementation manner of the first aspect of the embodiment of the present application, the third message further includes a third identifier, and the third identifier is used to identify a subscription of the first event.

With reference to the sixteenth implementation manner of the first aspect, in a seventeenth implementation manner of the first aspect of this embodiment of the present application, the third identifier is an SMF subscription association identifier.

With reference to any one of the first implementation manner of the first aspect to the fourth implementation manner of the first aspect, in an eighteenth implementation manner of the first aspect of this embodiment of the present application, the first identifier is a transaction identifier, which indicates a transaction between the first SMF and the second SMF, and corresponds to a subscription of the first event.

With reference to the eighteenth implementation manner of the first aspect, in a nineteenth implementation manner of the first aspect in this embodiment of the application, the transaction identifier is an NEF notification association identifier, and the NEF notification association identifier is used to identify a subscription of the first event.

A second aspect of the embodiments of the present application provides a method for providing policy rules, where the method includes:

When an application requests to subscribe to a first event, a second SMF may receive a second message sent by the first SMF, where the second message includes first description information and event subscription type indication information, the event subscription type indication information is used to indicate a type of an event subscription, that is, a type of the first event, and the first description information is used to identify data received by a UE, and in this embodiment, the first description information may also be referred to as first data description information;

the second SMF sends a seventh message to a policy control network element PCF, wherein the seventh message is used for requesting a third policy rule corresponding to the first description information, the seventh message comprises the first description information and a downlink data notification event subscription trigger, and the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

the second SMF receives the third policy rule sent by the PCF;

the second SMF determines a first policy rule according to the third policy rule;

the second SMF sends a first policy rule to the first SMF.

In the embodiment of the application, a second SMF which can directly interact with a PCF receives first description information and event subscription type indication information which are sent by a first SMF which cannot directly interact with the PCF, requests a PCF for a third policy rule generated according to the first description information, thereby generating a corresponding first policy rule, and sends the first policy rule to the first SMF, so that the first SMF obtains the first policy rule generated according to the third policy rule.

With reference to the second aspect, in a first implementation form of the second aspect of the examples of this application,

before the second SMF receives the second message sent by the first SMF, the method further includes:

the second SMF receives first request strategy indication information sent by the PCF, wherein the first request strategy indication information comprises indication information for reporting the subscription of a received downlink data notification event;

the second SMF sends second request policy indication information to the first SMF, wherein the second request policy indication information comprises at least one of indication information of policy charging control applied to the UE, indication information of the report received downlink data notification event subscription or indication information of the report received data description information; the second request policy indication information is used for indicating the first SMF to acquire the policy rule corresponding to the subscription event.

In the embodiment of the application, the second SMF sends the second request policy instruction information to the first SMF, and notifies the first SMF to acquire the policy rule corresponding to the subscription event from the PCF, so that the first SMF acquires the policy rule generated by the PCF through the second SMF, and thus acquires the policy rule required by the subscription event.

In combination with the second aspect and the first embodiment of the second aspect, in a second embodiment of the second aspect of the examples of the present application,

if the third policy rule sent by the PCF received by the second SMF includes:

the second SMF receives a third policy rule and notification control indication information sent by the PCF, and the notification control indication information is determined according to the downlink data notification event subscription trigger;

the second SMF sending the first policy rule to the first SMF comprises:

the second SMF sends the first policy rule and notification control indication information to the first SMF.

In the embodiment of the application, the second SMF sends the notification control indication information while sending the first policy rule to the first SMF, and the first SMF can determine the second policy rule directly according to the first policy rule and the notification control indication information without determining a first event corresponding to the first policy rule and then determine the second policy rule according to the first event, so that the operation resources and the time delay of the first SMF are saved, and the efficiency is improved.

With reference to the second aspect and any one of the first implementation manner to the second implementation manner of the second aspect, in a third implementation manner of the second aspect of the embodiment of the present application, when updating the first event subscription, providing a corresponding policy rule:

the second message also comprises a first identifier, wherein the first identifier is used for identifying a transaction between the second SMF and the first SMF and corresponds to the subscription of the first event;

after the second SMF sends the seventh message to the PCF, the method further comprises:

the second SMF receives a fourth message sent by the first SMF, wherein the fourth message comprises the first identifier and second description information of the data, and the fourth message is used for requesting to update the subscription of the first event;

the second SMF sends an eighth message to the PCF, wherein the eighth message comprises a second identifier and second description information, the eighth message is used for requesting to update a third policy rule, the second identifier is the identifier information of the third policy rule, and the second identifier is determined according to the first identifier;

the second SMF receives a fifth policy rule sent by the PCF, where the fifth policy rule is obtained by updating the third policy rule according to the second description information;

the second SMF updates the first strategy rule according to a fifth strategy rule to obtain a fourth strategy rule;

the second SMF sends a fourth policy rule to the first SMF.

In this embodiment of the application, the second SMF updates the first policy rule according to the second description information to obtain a fourth policy rule, and sends the fourth policy rule to the first SMF, so that the first SMF generates a policy rule corresponding to the second description information. And updating the event subscription after the event subscription is completed.

With reference to the third implementation manner of the second aspect, in a fourth implementation manner of the second aspect of this embodiment of the present application, after the second SMF receives the fourth message sent by the first SMF, the method further includes:

the second SMF receives an eleventh message sent by the first SMF, where the eleventh message is used to request the second SMF to update the fourth policy rule, and the eleventh message includes the first identifier and third description information of the data, where the third description information may also be referred to as third data description information;

the second SMF sends the second identifier and the third description information to the PCF to request the PCF to update the fifth policy rule according to the third description information;

the second SMF receives a seventh policy rule sent by the PCF, where the seventh policy rule is obtained by updating the fifth policy rule according to the third description information;

the second SMF updates the fourth strategy rule according to a seventh strategy rule to obtain a sixth strategy rule;

the second SMF sends a sixth policy rule to the first SMF.

In the embodiment of the present application, the second SMF sends the third description information and the second identifier to the PCF, so that the PCF updates the fifth policy rule according to the third description information to obtain a seventh policy rule, and receives the seventh policy rule sent by the PCF, thereby generating a sixth policy rule corresponding to the third description information. Updating of the event subscription again is achieved after updating of the event subscription.

With reference to the second aspect and any one of the first implementation manner to the fourth implementation manner of the second aspect, in a fifth implementation manner of the second aspect of the embodiment of the present application, deletion of an event subscription may also be implemented:

the second SMF receives a sixth message sent by the first SMF, wherein the sixth message comprises the first identifier and a deletion instruction;

and the second SMF sends a ninth message to the PCF, wherein the ninth message is used for requesting to delete the third policy rule, the ninth message comprises a second identifier, the second identifier is the identifier information of the third policy rule, and the second identifier is determined according to the first identifier.

In this embodiment of the present application, the second SMF sends the ninth message to the PCF, so that the PCF deletes the third policy rule according to the second identifier in the ninth message, thereby implementing deletion of the event subscription.

With reference to the third implementation manner of the second aspect, in a sixth implementation manner of the second aspect of this embodiment of the present application, deletion of an updated event subscription may also be implemented:

after the second SMF sends the second identity and the third description information to the PCF, the method further comprises:

the second SMF receives a thirteenth message sent by the first SMF, wherein the thirteenth message comprises the first identifier and a deletion instruction;

and the second SMF sends a fourteenth message to the PCF, wherein the fourteenth message is used for requesting to delete the fifth policy rule, the fourteenth message comprises a second identifier, and the second identifier is used for identifying the fifth policy rule.

In this embodiment of the present application, the second SMF sends a fourteenth message to the PCF, so that the PCF deletes the fifth policy rule according to the second identifier in the fourteenth message, thereby implementing deletion of the updated event subscription.

With reference to the second aspect and any one of the first embodiment to the sixth embodiment of the second aspect, in a seventh embodiment of the second aspect of the examples herein,

With reference to the second aspect and any one of the first implementation manner to the seventh implementation manner of the second aspect, in an eighth implementation manner of the second aspect of the embodiments of the present application, the third policy rule is a PCC rule.

With reference to the second aspect and any one of the first implementation manner of the second aspect to the eighth implementation manner of the second aspect, in a ninth implementation manner of the second aspect of the examples of the present application, the first policy rule is the first N4 information.

With reference to the second implementation manner of the second aspect, in a tenth implementation manner of the first aspect of the embodiment of the present application, the notification control indication information is included in the third policy rule.

In the embodiment of the present application, the notification control indication information is included in the third policy rule, and in the process of forwarding and using the first policy rule, the notification control indication information is included in the third policy rule, so that the notification control indication information does not need to be processed separately, and the operation resource of the device is saved.

With reference to the second implementation manner of the second aspect, in an eleventh implementation manner of the second aspect of the examples of the present application, the notification control indication information is included in the first policy rule.

In the embodiment of the present application, the notification control indication information is included in the first policy rule, and in the process of forwarding and using the first policy rule, the notification control indication information is included in the first policy rule, so that the notification control indication information does not need to be processed separately, and the operation resource of the device is saved.

With reference to any one of the third implementation manner of the second aspect to the sixth implementation manner of the second aspect, in a twelfth implementation manner of the second aspect of the embodiment of the present application, the first identifier is a transaction identifier, which indicates a transaction between the first SMF and the second SMF, and corresponds to a subscription of the first event.

With reference to the twelfth implementation manner of the second aspect, in a thirteenth implementation manner of the second aspect of the embodiment of the present application, the transaction identifier is an NEF notification association identifier, and the NEF notification association identifier is used to identify a subscription of the first event.

A third aspect of the embodiments of the present application provides a session management network element, including:

a first receiving unit, configured to receive a first message, where the first message is used to request to create a subscription for a first event, the subscription for the first event is an event subscription for a user equipment UE, and the first message includes first description information of data, where the data is data received by the UE;

a first sending unit, configured to send a second message to a second session management network element SMF according to a request policy indication information, where the second message includes the first description information, and the second message is used to request a first policy rule corresponding to the first description information;

a second receiving unit, configured to receive the first policy rule sent by the second SMF;

a first determining unit, configured to determine a second policy rule according to the first policy rule;

a second sending unit, configured to send the second policy rule to a user plane function network element UPF, so that the UPF processes the data.

The session management network element is configured to perform the method of the first aspect.

A fourth aspect of the present embodiment provides a session management network element, including:

a seventh receiving unit, configured to receive a second message sent by a first session management network element SMF, where the first message includes first description information and event subscription type indication information, the event subscription type indication information is used to indicate a type of event subscription, the event subscription is an event subscription for a user equipment UE, and the first description information is used to identify data received by the UE;

a fifth sending unit, configured to send a seventh message to a policy control network element PCF, where the seventh message is used to request a third policy rule corresponding to the first description information, and the seventh message includes the first description information and a downlink data notification event subscription trigger, where the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

an eighth receiving unit, configured to receive the third policy rule sent by the PCF;

a second determining unit, configured to determine the first policy rule according to the third policy rule;

a sixth sending unit, configured to send the first policy rule to the first SMF.

The session management network element is configured to perform the method of the second aspect.

A fifth aspect of the present application provides a session management network element, including:

a processor, a memory, an input-output device, and a bus;

the processor, the memory and the input and output equipment are connected with the bus;

the processor is configured to perform the steps of:

receiving a first message, where the first message is used to request to create a subscription for a first event, the subscription for the first event is an event subscription for a User Equipment (UE), and the first message includes first description information of data, where the data is data received by the UE;

sending a second message to a second session management network element (SMF) according to the request policy indication information, wherein the second message comprises the first description information, and the second message is used for requesting a first policy rule corresponding to the first description information;

receiving the first policy rule sent by the second SMF;

determining a second policy rule according to the first policy rule;

and sending the second policy rule to a user plane function network element (UPF) so that the UPF processes the data.

A sixth aspect of an embodiment of the present application provides a session management network element, including:

a processor, a memory, an input-output device, and a bus;

the processor is configured to perform the steps of:

receiving a second message sent by a first session management network element (SMF), wherein the first message comprises first description information and event subscription type indication information, the event subscription type indication information is used for indicating the type of event subscription, the event subscription is the event subscription for User Equipment (UE), and the first description information is used for identifying data received by the UE;

sending a seventh message to a policy control network element PCF, where the seventh message is used to request a third policy rule corresponding to the first description information, the seventh message includes the first description information and a downlink data notification event subscription trigger, and the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

receiving the third policy rule sent by the PCF;

determining a first policy rule according to the third policy rule;

sending the first policy rule to the first SMF.

A seventh aspect of the embodiments of the present application provides a method for providing policy rules, where the method includes:

When an application requests to subscribe to a first event, a first session management network element SMF may receive a first policy rule sent by a second SMF, where the first policy rule is generated according to first description information of data, where the data is data received by a UE, and in this embodiment, the first description information may also be referred to as first data description information;

In the embodiment of the application, the first SMF which cannot directly interact with the PCF receives the first policy rule generated by the second SMF according to the first description information, so as to generate the corresponding policy rule. The first SMF completes the subscription of the event under the condition that the first SMF cannot be directly connected with the PCF.

With reference to the seventh aspect, in the first implementation manner of the seventh aspect of this embodiment of the present application, when updating the first event subscription, providing a corresponding policy rule:

specifically, after the first SMF receives the first policy rule sent by the second SMF,

the first SMF receives a fourth policy rule sent by the second SMF, wherein the fourth policy rule is obtained by updating the first policy rule according to the second description information of the data;

In this embodiment of the application, the second SMF updates the first policy rule according to the second description information to obtain a fourth policy rule, and the first SMF receives the fourth policy rule sent by the second SMF, thereby generating the policy rule corresponding to the second description information. And updating the event subscription after the event subscription is completed.

With reference to the first implementation manner of the seventh aspect, in a second implementation manner of the seventh aspect of this embodiment of the present application, after the first SMF receives the fourth policy rule sent by the second SMF, the method further includes:

the first SMF receives a sixth policy rule sent by the second SMF, wherein the sixth policy rule is obtained by updating the fourth policy rule according to the third description information of the data;

In this embodiment of the application, the second SMF updates the fourth policy rule according to the third description information to obtain a sixth policy rule, and the first SMF receives the sixth policy rule sent by the second SMF, so as to generate the policy rule corresponding to the third description information. Updating of the event subscription again is achieved after updating of the event subscription.

With reference to the seventh aspect, in a third implementation manner of the seventh aspect of this embodiment of the present application, deletion of an event subscription may also be implemented:

the first SMF receives an instruction sent by the second SMF for deleting the first policy rule;

and the first SMF deletes the first policy rule and sends an instruction for deleting the second policy rule to the UPF.

In this embodiment of the present application, the first SMF receives an instruction to delete the first policy rule sent by the second SMF, and deletes the first policy rule according to the instruction. Deletion of event subscriptions is achieved.

With reference to the first implementation manner of the seventh aspect, in a fourth implementation manner of the seventh aspect of this embodiment of the present application, deletion of the updated subscription to the first event may also be implemented:

specifically, after the first SMF receives the fourth policy rule sent by the second SMF,

the first SMF receives an instruction sent by the second SMF for deleting the fourth policy rule;

the first SMF deletes the fourth policy rule and sends an indication to the UPF to delete the policy rule associated with the first event.

In this embodiment of the present application, the first SMF receives an instruction to delete the fourth policy rule sent by the second SMF, and deletes the fourth policy rule according to the instruction. Deletion of updated event subscriptions is achieved.

With reference to the seventh aspect and any one of the first to fourth embodiments of the seventh aspect, in a fifth embodiment of the seventh aspect of the examples of this application,

the first SMF receives a first policy rule and notification control indication information sent by a second SMF, and the notification control indication information is determined according to the subscription of the first event;

With reference to the seventh aspect and any one of the first to fourth embodiments of the seventh aspect, in a sixth embodiment of the seventh aspect of the examples of this application,

In the embodiment of the application, the first SMF determines the second policy rule according to the first policy rule and the subscription of the first event, and notification control indication information does not need to be carried in messages sent and received by the second SMF, so that computational resources and network bandwidth resources of a network element which needs to send and receive and determine the indication information in a network are saved.

With reference to the seventh aspect and any one of the first implementation manner to the sixth implementation manner of the seventh aspect, in a seventh implementation manner of the seventh aspect of the embodiments of the present application,

With reference to the seventh implementation manner of the seventh aspect, in the eighth implementation manner of the seventh aspect of the examples of this application,

With reference to the seventh aspect and any one of the first to eighth implementations of the seventh aspect, in a ninth implementation of the seventh aspect of the embodiments of the present application,

With reference to the seventh aspect and any one of the first implementation manner to the ninth implementation manner of the seventh aspect, in a tenth implementation manner of the seventh aspect of the example of the present application, the first policy rule is the first N4 information.

With reference to the seventh aspect and any one of the first implementation manner to the tenth implementation manner of the seventh aspect, in an eleventh implementation manner of the seventh aspect of the example of the present application, the second policy rule is second N4 information.

With reference to the seventh aspect and any one of the first implementation manner to the eleventh implementation manner of the seventh aspect, in a twelfth implementation manner of the seventh aspect of this embodiment of the present application, specifically, before the first SMF receives the first policy rule sent by the second SMF, the first SMF sends, to the second SMF, an indication that the data is cached in the UPF or an indication that the policy rule is needed.

With reference to the fifth implementation manner of the seventh aspect, in a thirteenth implementation manner of the seventh aspect of this embodiment of the present application, the notification control indication information is included in the first policy rule.

An eighth aspect of the present application provides a method for providing policy rules, where the method includes:

When an application requests to subscribe to a first event, the second SMF may send a seventh message to the PCF according to the first request policy indication information, where the seventh message includes first description information and a downlink data notification event subscription trigger, the downlink data notification event subscription trigger is determined according to the event subscription type indication information, the event subscription type indication information is used to indicate a type of event subscription, that is, a type of the first event, and the first description information is used to identify data received by the UE, and in this embodiment of the present application, the first description information may also be referred to as first data description information;

the second SMF receives the third policy rule sent by the PCF;

the second SMF sends a first policy rule to the first SMF.

In the embodiment of the application, the second SMF capable of directly interacting with the PCF requests the PCF for the third policy rule generated according to the first description information, so as to generate the corresponding first policy rule, and then sends the first policy rule to the first SMF, so that the first SMF obtains the first policy rule generated according to the third policy rule.

With reference to the eighth aspect, in a first implementation manner of the eighth aspect of the embodiment of the present application,

before the second SMF sends the seventh message to the PCF according to the first request policy indication information, the method further comprises:

in the embodiment of the application, the second SMF receives the first request policy indication information sent by the PCF, so that the second SMF can acquire the policy rule corresponding to the subscription event from the PCF, and thus, the first SMF acquires the policy rule generated by the PCF through the second SMF, and thus, acquires the policy rule required by the subscription event.

With reference to the eighth aspect and the first embodiment of the eighth aspect, in a second embodiment of the eighth aspect of the examples of the present application,

if the third policy rule sent by the PCF received by the second SMF includes:

the second SMF receives a third policy rule and notification control indication information sent by the PCF, and the notification control indication information is determined according to the event subscription type indication information;

the second SMF sending the first policy rule to the first SMF comprises:

With reference to the eighth aspect and any one of the first implementation manner to the second implementation manner of the eighth aspect, in a third implementation manner of the eighth aspect of the embodiment of the present application, when updating the first event subscription, providing a corresponding policy rule:

the second SMF receives a third identifier and second description information of the data, wherein the second description information is used for updating the subscription of the first event, and the third identifier is used for identifying the subscription of the first event;

the second SMF sends an eighth message to the PCF, wherein the eighth message comprises a second identifier and second description information, the eighth message is used for requesting to update a third policy rule, the second identifier is the identifier information of the third policy rule, and the second identifier is determined according to the third identifier;

the second SMF sends a fourth policy rule to the first SMF.

With reference to the third implementation manner of the eighth aspect, in a fourth implementation manner of the eighth aspect of this embodiment of the present application, after the second SMF receives the third identifier and the second description information, the method further includes:

the second SMF receives a third identifier and third description information of the data, where the third description information may also be referred to as third data description information, and the third identifier is used to identify a subscription of the first event;

the second SMF sends a sixth policy rule to the first SMF.

With reference to the eighth aspect and any one of the first to fourth implementations of the eighth aspect, in a fifth implementation of the eighth aspect of the embodiment of the present application, deletion of an event subscription may also be implemented:

the second SMF receives a third identifier and a deletion instruction, wherein the third identifier is used for identifying the subscription of the first event;

and the second SMF sends a ninth message to the PCF, wherein the ninth message is used for requesting to delete the third policy rule, the ninth message comprises a second identifier, and the second identifier is used for identifying the third policy rule.

With reference to the third implementation manner of the eighth aspect, in a sixth implementation manner of the eighth aspect of this embodiment of the present application, deletion of an updated event subscription may also be implemented:

the second SMF sends a fourteenth message to the PCF, where the fourteenth message is used to request deletion of the fifth policy rule, and the fourteenth message includes a second identifier, where the second identifier is used to identify the fifth policy rule;

and the second SMF sends an instruction for deleting the fourth policy rule to the first SMF.

In this embodiment of the present application, the second SMF sends a fourteenth message to the PCF, so that the PCF deletes the fifth policy rule according to the second identifier in the fourteenth message, and sends an instruction to delete the fourth policy rule to the first SMF, so that the first SMF deletes the fourth policy rule, thereby implementing deletion of the updated event subscription.

With reference to the eighth aspect and any one of the sixth implementation manners of the first to eighth aspects of the eighth aspect, in a seventh implementation manner of the eighth aspect of the examples of the present application,

With reference to the eighth aspect and any one of the first implementation manner to the seventh implementation manner of the eighth aspect, in an eighth implementation manner of the eighth aspect of the example of the present application, the first policy rule is the first N4 information.

With reference to the eighth aspect and any one of the eighth implementation manners of the eighth aspect to the eighth aspects, in a ninth implementation manner of the eighth aspect of the example of the present application, the third policy rule is a PCC rule.

With reference to the eighth aspect and any one of the first implementation manner to the ninth implementation manner of the eighth aspect, in a tenth implementation manner of the seventh aspect of the embodiment of the present application, specifically, before the second SMF sends the seventh message to the PCF according to the first request policy indication information, the second SMF receives an indication that the data cache sent by the first SMF is in the UPF or an indication that the policy rule is needed.

With reference to the third implementation manner of the eighth aspect, in an eleventh implementation manner of the eighth aspect of this embodiment of the present application, the third identifier is an SMF subscription association identifier.

With reference to the second implementation manner of the eighth aspect, in a twelfth implementation manner of the eighth aspect of the embodiments of the present application, the notification control indication information is included in the third policy rule.

With reference to the second implementation manner of the eighth aspect, in a thirteenth implementation manner of the first aspect of the embodiments of the present application, the notification control indication information is included in the first policy rule.

With reference to the third implementation manner of the eighth aspect, in a fourteenth implementation manner of the first aspect of this embodiment of the present application, the third identifier is an SMF subscription association identifier.

With reference to the third implementation manner of the eighth aspect, in a fourteenth implementation manner of the first aspect of this embodiment of the present application, the third identifier is an NEF subscription association identifier.

A ninth aspect of the present application provides a session management network element, including:

a first receiving unit, configured to receive a first policy rule sent by a second SMF, where the first policy rule is generated according to first description information of data, where the data is data received by a UE, and in this embodiment of the present application, the first description information may also be referred to as first data description information;

and the first sending unit is used for sending the second policy rule to the user plane function network element UPF so that the UPF can process the data.

The session management network element is configured to perform the method of the seventh aspect.

A tenth aspect of the present embodiment provides a session management network element, including:

a second sending unit, configured to send a seventh message to the PCF according to the first request policy indication information, where the seventh message includes first description information and a downlink data notification event subscription trigger, the downlink data notification event subscription trigger is determined according to the event subscription type indication information, the event subscription type indication information is used to indicate a type of event subscription, that is, a type of a first event, and the first description information is used to identify data received by the UE, and in this embodiment of the present application, the first description information may also be referred to as first data description information;

a second receiving unit, configured to receive the third policy rule sent by the PCF;

a third sending unit, configured to send the first policy rule to the first SMF.

The session management network element is configured to perform the method of the aforementioned eighth aspect.

An eleventh aspect of an embodiment of the present application provides a session management network element, including:

a processor, a memory, an input-output device, and a bus;

the processor is configured to perform the steps of:

receiving a first policy rule sent by a second SMF, where the first policy rule is generated according to first description information of data, where the data is data received by the UE, and in this embodiment, the first description information may also be referred to as first data description information;

determining a second policy rule according to the first policy rule;

and sending a second policy rule to a user plane function network element UPF so that the UPF processes the data.

A twelfth aspect of an embodiment of the present application provides a session management network element, including:

a processor, a memory, an input-output device, and a bus;

the processor is configured to perform the steps of:

sending a seventh message to the PCF according to the first request policy indication information, where the seventh message includes first description information and a downlink data notification event subscription trigger, where the downlink data notification event subscription trigger is determined according to the event subscription type indication information, the event subscription type indication information is used to indicate a type of event subscription, that is, a type of a first event, and the first description information is used to identify data received by the UE, and in this embodiment, the first description information may also be referred to as first data description information;

receiving the third policy rule sent by the PCF;

determining a first policy rule according to a third policy rule;

sending a first policy rule to the first SMF.

A thirteenth aspect of embodiments of the present application provides a computer-readable storage medium, which stores a program, and when the computer executes the program, the computer performs the method described in the foregoing first aspect, second aspect, seventh aspect, and eighth aspect.

A fourteenth aspect of embodiments of the present application provides a computer program product, which when executed on a computer, executes the method described in the foregoing first, second, seventh and eighth aspects.

Drawings

FIG. 1 is a schematic diagram of a network framework with open service capabilities;

FIG. 2 is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 3 is a flowchart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 4a is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 4b is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 5a is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 5b is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 6 is another schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 7 is another flowchart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 8a is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 8b is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 9a is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

FIG. 9b is a schematic flow chart illustrating a method for providing policy rules according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a session management network element in an embodiment of the present application;

fig. 11 is a schematic structural diagram of a session management network element in an embodiment of the present application;

fig. 12 is a schematic structural diagram of a session management network element in an embodiment of the present application;

fig. 13 is a schematic structural diagram of a session management network element in an embodiment of the present application;

fig. 14 is a schematic structural diagram of a session management network element in an embodiment of the present application.

Detailed Description

Referring to fig. 1, fig. 1 is an architecture diagram of an open service capability function (SCEF) supporting interworking between 4G/5G and a next generation mobile communication network. Based on the architecture, the 3GPP network can securely provide service capability to the Application Function (AF) of the third-party application service provider (3drd party ASP,3drd party application service provider). A Network Exposure Function (NEF) is a core network element in the architecture, so that the 3GPP network can safely provide service capability to a Service Capability Server (SCS) or an Application Server (AS) of a third party. A unified data management function (UDM) is a unified data management network element that stores subscription information of users. The core network access and mobility management function (AMF) is a network element responsible for mobility management of the UE in 5G and next generation mobile communication networks. A Session Management Function (SMF) is 5G and a network element in the next generation mobile communication network that is responsible for managing a PDU session of a User Equipment (UE). The AF calls the business capabilities provided by the NEF through the API interface of the Nnef service.

In one example, when an application subscribes to an event that requires detection of data transmission at the UPF, a corresponding policy that is enforced at the UPF needs to be generated according to PCC rules. The policy may be a Packet Detection Rule (PDR), or other rules related to packet transmission, such as a Forwarding Action Rule (FAR), a Usage Reporting Rule (URR), and the like, which is not limited herein.

In this embodiment, all messages, including a subscription request message, an update context request message, an update request message, an acknowledgement message, and the like, are examples of a sending message, and do not constitute a limitation to the messages, as long as the messages carry data described in this embodiment, the messages described in this embodiment may be regarded as messages described in this embodiment, and the details are not limited herein.

The embodiment of the application provides a method for obtaining a PCC rule through a second SMF capable of directly interacting with a PCF, and accordingly formulating a policy rule for UPF detection data packets according to the PCC rule.

In this embodiment, the V-SMF may also be referred to as a first SMF, the first SMF cannot interact with the PCF, and in this embodiment, other first SMFs that cannot interact with the PCF may be used instead of the V-SMF, for example, I-SMF, and this embodiment is not limited herein specifically, and in this embodiment, the V-SMF is taken as an example and is not limited to the first SMF.

In the embodiment of the present application, the first and second are only to distinguish similar subjects, for example, to distinguish a first SMF that interacts with a UPF but cannot directly interact with a PCF and a second SMF that can directly interact with a PCF; or for distinguishing between first data description information provided at event subscription and second data description information provided at event update, the first and second not causing a limitation to the similar subject.

In the embodiment of the present application, the triplet information may also be referred to as data description information (traffic descriptors). The data description information may also be referred to as description information, and is used to identify downstream data of an application. Besides the triplet information, the data description information may also be other information, such as a MAC address or a VLAN ID for identifying the application server, which is not limited herein. The embodiments of the present application only take the triplet information as an example, and do not limit the data description information.

Specifically, the triplet information is IP triplet information used to identify an address, a port number, and a protocol type of the application server.

Specifically, in an embodiment of the event subscription, for example, the embodiment shown in fig. 2, fig. 3, fig. 6, or fig. 7, the triplet information is the first data description information; in an embodiment of event update, such as the embodiment shown in fig. 4a, 4b, 8a or 8b, the triplet information is the second data description information.

The application may subscribe to different events to the network, for example, a reachable event after a failure of downlink data delivery, or may also be other events, for example, a downlink data delivery status event, which is not limited herein. The process of providing the policy rules for different events will be illustrated below.

Firstly, acquiring a policy rule of an reachable event after a downlink data notification fails:

1. and (3) reaching an event after the failure of subscribing the downlink data notification:

in this embodiment of the present application, an reachable event (reachable after downlink data notification failure) may also be referred to as a reachable event after downlink data transmission failure or a reachable event after downlink data transmission failure.

In this embodiment of the present application, the first SMF may request the PCF for the PCC rule, or the second SMF may request the PCF for the PCC rule, which will be described below:

1.1, the first SMF requests a PCC rule from the PCF:

referring to fig. 2, when the UE is in a roaming state, i.e. the V-SMF cannot directly interact with the PCF, the first SMF requests the PCF for a PCC rule for an reachable event after a failure of the AF subscription for downlink data delivery. For the scenario that the PDU session has I-SMF, the V-SMF may be replaced by I-SMF, which is not limited herein. One process for providing policy rules in the embodiments of the present application includes:

201. UE accesses to the network and establishes PDU conversation:

the UE accesses the network and establishes a PDU session that establishes a data path from the UE to the UPF. The UE may interact with the application server through this data channel.

Optionally, during the PDU session establishment or modification process, the PCF may send a Policy Control Request Trigger (PCRT) to the second SMF, where the trigger notifies a failure event subscription (downlink data notification failure event subscribed with traffic descriptor) for the downlink data carrying the data description. The PCRF is used for indicating the second SMF to request the PCC rule from the PCF when receiving the subscription of the downlink data notification failure event carrying the data description. In the embodiment of the present application, the PCRT is also referred to as a downlink data notification event subscription trigger.

Optionally, during PDU session establishment or modification, the PCF may send an indication to the second SMF reporting receipt of the downstream data notification event subscription. In the embodiment of the present application, this indication information is also referred to as first request policy indication information.

Further, the second SMF may send, to the V-SMF, the indication information for determining that the policy charging control is applied to the UE, the indication information for reporting that the downlink data notification failure event subscription is received, or the indication information for reporting that the data description information is received, according to the PCRT of the downlink data notification failure event subscription that carries the data description.

In this embodiment of the application, the indication information may also be referred to as request policy indication information or second request policy indication information, and is used to instruct the first SMF to acquire a policy rule corresponding to the subscription event.

In this embodiment of the present application, a downlink data notification failure event (downlink data notification failure event) may also be referred to as a downlink data transmission failure event or a downlink data transfer failure event, and in this embodiment of the present application, this event is also referred to as a first event.

202. The AF sends a subscription request message to the NEF:

the AF sends a Nnef _ EventExpo _ Subscribe Request message to the NEF, and subscribes an reachable (availability after downlink data notification failure) event after the transmission of downlink data fails.

The message carries an event identifier (event id), an AF notification endpoint (AF notification endpoint), an external identifier of the user or an external user group identifier, and triple information.

In the embodiment of the present application, the data description information provided at the time of event subscription is referred to as first data description information, and the data description information provided at the time of event update is referred to as second data description information. In this embodiment or the embodiment shown in fig. 3, the data description information is the first data description information.

The event identifier (event id) represents a subscribed event, and in this embodiment, is an identifier of an reachable event after a failure of downlink data notification.

The AF notification endpoint is configured to indicate an endpoint at which the AF receives an event notification, and may include an AF notification target address (AF notification target address). When the AF allocates the same AF notification target address to a plurality of subscription notifications, different subscriptions may be distinguished by the AF notification association identifier, where the AF notification endpoint includes an AF notification target address (AF notification target address) and an AF notification association identifier (AF notification correlation Id).

203. NEF sends subscription request message to UDM:

the NEF sends a Nudm _ EventExpo _ Subscripte Request message to the UDM, and subscribes the reachable event after the downlink data notification fails.

The message carries the event identifier, the triple information, and the external identifier or the external user group identifier of the user received in step 202, and an NEF notification endpoint (NEF notification endpoint) where the NEF is configured to receive the subscription notification.

The NEF notification endpoint is configured to indicate an endpoint, where the NEF is configured to receive a subscription notification, and is configured to identify to which NEF network element the detected reachable event is fed back after the downlink data notification fails, where the NEF notification endpoint may include a NEF notification target address (NEF notification target address) and a NEF notification association identifier (NEF notification correlation Id). When the NEF assigns the same NEF notification target address to a plurality of subscription notifications, different events can be distinguished by the NEF notification association identification.

204. The UDM sends a subscription request message to the AMF registered by the UE:

the UDM, having received the external identity of the user in step 203, can determine the internal identity of the user based on the external identity.

In this embodiment of the application, when the event subscription is directed to multiple users, the external identifier of the user in steps 202 and 203 may also be an external user group identifier, where the external user group identifier represents each of the users, and at this time, the internal identifier of each of the users may be determined according to the external user group identifier, which is not limited herein.

The UDM may determine the AMF registered by the UE according to the locally stored correspondence and the user internal identifier, and send a Namf _ EventExposure _ Subscribe Request message to the AMF registered by the UE, Subscribe to the reachable event after the downlink data notification fails.

The message carries the event identifier, triplet information, NEF notification endpoint received in step 203, and the user internal identifier.

If the user group identifier is received in step 203, the UDM may send the message to the AMF registered by the UE for each UE in the user group.

205. AMF returns confirmation message to UDM:

the AMF allocates an AMF subscription association identifier (AMF subscription association id) according to the event identifier received in step 204, where the AMF subscription association identifier is used to identify a subscription of a reachable event after a failure of downlink data notification, and indicates that the event has been successfully subscribed at the AMF.

And the AMF stores the received information and returns a confirmation message to the UDM, wherein the message carries the AMF subscription association identifier.

206. The UDM returns an acknowledgement message to the NEF:

the UDM assigns a UDM subscription association identifier (UDM subscription correlation id) to the event subscription, where the UDM subscription association identifier is used to identify an reachable event after a downlink data notification fails, and indicate that the event has been successfully subscribed at the UDM.

And the UDM returns a confirmation message to the NEF, wherein the confirmation message carries the UDM subscription association identifier.

207. The NEF returns an acknowledgement message to the AF:

the NEF assigns a NEF subscription association identifier (NEF subscription correlation id) to the event subscription, where the NEF subscription association identifier is used to identify a reachable event after a failure of downlink data notification, and indicates that the event subscription is successfully subscribed at the NEF.

The NEF stores the received information and returns a confirmation message to the AF, wherein the confirmation message carries the NEF subscription association identifier.

In the embodiment of the present application, step 206 may be performed before step 205 or 204 as long as it is performed after step 203; step 207 may be performed before any of steps 203 to 206 as long as it is performed after step 202, and is not limited herein.

There are two implementations of steps 208 to 214, which are as follows:

a: the message carries notification control indication information, and is used for generating a corresponding policy rule, and the specific implementation manner is as follows:

208. the AMF sends a first message to the V-SMF:

the AMF may generate downlink data notification failure (downlink data notification failure) notification indication information according to the subscription of the event in step 204, where the indication information is used to indicate a type of the event subscription, and specifically may be an event identifier of the downlink data notification failure event or another identifier allocated by the AMF, which is not limited herein.

And the AMF sends an Nsmf _ PDSUSessionUpdateSMContext Request message to the V-SMF and subscribes a downlink data notification failure event. In this embodiment, this message may also be referred to as a first message. In this embodiment of the present application, the first message is used to request the V-SMF to subscribe to an event, for example, in this embodiment, to request to subscribe to an event that causes a failure to create downlink data notification; in other embodiments, it may also be used to request to create subscriptions to other events; the first message may be other forms of messages, and the examples herein do not limit the first message.

The message carries the NEF notification association identifier, the triplet information, and the downlink data notification failure notification indication information received in step 204.

209. The V-SMF returns an acknowledgement message to the AMF.

210. The V-SMF determines that a policy rule for processing data needs to be requested, and sends a second message to a second SMF:

in step 201, the V-SMF receives indication information that policy charging control is applied to the UE, indication information that a downlink data notification failure event subscription is reported to be received, or indication information that data description information is reported to be received, and the V-SMF may determine that PCC is applied to the PDU session, and when the V-SMF determines that data needs to be cached in the UPF, may also determine that the received event subscription needs to be reported to a second SMF and request a policy for processing the data in the UPF.

The V-SMF may assign a Transaction identity (Transaction Id) to the event, the Transaction identity being used to represent a Transaction between the V-SMF and a second SMF for subsequent modify and delete operations, and the Transaction identity also being used to identify a policy rule request for the first event subscription. In the embodiment of the present application, the transaction identifier may also be referred to as first identification information. In an embodiment of the application, the transaction identification corresponds to a subscription of the first event. In this embodiment, the transaction identifier corresponds to a subscription of a downlink data notification failure event.

The V-SMF may also allocate DDN _ Failure indication information according to the subscription of the event in step 208, where the DDN _ Failure indication information is used to indicate that the received event subscription type is a downlink data notification Failure subscription.

The DDN _ Failure indication information is also referred to as event subscription type indication information in the present embodiment. In the embodiment of the present application, the event subscription type indication information is used to indicate a type of an event subscription, and is generated according to the subscription of an event, and in the subscription of other events, the event subscription type indication information may also be used to indicate an event subscription of other events, for example, an event subscription of a downlink data transfer state event, which is not limited herein.

Specifically, the event subscription type indication information may be generated according to the indication information indicating the event subscription type in step 208, or may also be the indication information indicating the event subscription type in step 208, which is not limited herein.

Specifically, the V-SMF sends an Nsmf _ pdusesion _ Update Request message to the second SMF, reports the received event subscription, and requests a policy for detecting data. The message carries triple information, the Transaction identifier (Transaction Id) and the DDN _ Failure indication information. In this embodiment, this message may also be referred to as a second message. In this embodiment of the application, the second message is used to request, from the second SMF, a policy rule for processing data corresponding to the subscription event.

In the embodiment of the present application, step 210 may also be performed before step 209, as long as it is performed after step 208, and is not limited herein.

211. The second SMF sends a seventh message to the PCF:

in step 210, the second message received by the second SMF includes both the triplet information and the transaction identifier.

After receiving the transaction identifier, the second SMF needs to request the PCF for a PCC rule for detecting a failure event of downlink data delivery, and since the PCF provides the PCRT carrying a subscription for a failure event of downlink data notification described by data, the second SMF may send an Npcf _ SMPolicyControl _ Update request message to the PCF. In this embodiment, this message may also be referred to as a seventh message. In this embodiment of the present application, the seventh message is used to request the PCC rule from the PCF.

The second SMF determines, according to the DDN _ Failure indication information in the second message, that the message is used to request a PCC rule for detecting a downlink data transfer Failure event, and the second SMF may find the PCRT corresponding to the event received in step 201.

The triplet information received in step 210 and the PCRT are carried in the message.

Optionally, the message may further carry an operation indication Create, which indicates that the message is used to request a new PCC rule.

212. PCF makes PCC rule, and sends third policy rule to second SMF:

the PCF formulates a PCC rule (PCC rule) according to the triplet information received in step 211, that is, a filter template in the PCC rule includes the triplet information, and sets a high priority, where the PCC rule includes a PCC rule identifier (PCC rule Id), and the PCC rule identifier is used to represent the PCC rule, and when the PCC rule is subsequently updated or deleted, the corresponding PCC rule may be determined according to the PCC rule identifier, so as to change the PCC rule. In the embodiment of the present application, the PCC rule identification may also be referred to as second identification information.

The PCF may also determine DDN Failure notification control indication information according to the PCRT received in step 211, where the DDN Failure notification control indication information is used to indicate that DNN Failure notification needs to be performed. The DDN Failure notification control indication information may be included in the PCC rule, and is used to indicate that the PCC rule is used to detect a downlink data notification Failure event.

The DDN _ Failure notification control indication information is also referred to as notification control indication information in the present embodiment. In this embodiment of the application, the notification control indication information is used to indicate an action corresponding to the event subscription, and is generated according to the event subscription type indication information.

And the PCF returns a confirmation message to the second SMF, wherein the message carries the PCC rule. In this embodiment of the present application, the PCC rule generated in the event subscription process may also be referred to as a third policy rule.

Optionally, the DDN Failure notification control indication information may also be carried in the acknowledgement message instead of being included in the PCC rule, and is not limited herein.

213. The second SMF receives the third policy rule, generates the first N4 message (N4 information), and sends the first policy rule to the V-SMF:

when the second SMF receives the PCC rule (third policy rule) of step 212, since the second message in step 210 includes the triplet information and the transaction identifier at the same time, and the PCC rule is generated according to the triplet information, the second SMF may determine and store the corresponding relationship between the transaction identifier and the PCC rule identifier accordingly. When the subsequent failed subscription notification of the downlink data is updated or deleted, the PCC rule identifier corresponding to the event may be found according to the corresponding relationship, so as to send a corresponding instruction to the PCF, and enable the PCF to update or delete the PCC rule corresponding to the PCC rule identifier.

And the second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCC rule or the acknowledgment message in step 212 includes DDN Failure notification control indication information, so the first N4 information may also include DDN Failure notification control indication information, and the first PDR is determined according to the PCC rule and carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information. In this embodiment of the present application, the first N4 information generated in the event subscription process may also be referred to as a first policy rule.

Optionally, the DDN Failure notification control indication information may not be included in the first N4 information, but is carried in the acknowledgement message, which is not limited herein.

214. The V-SMF sends a second N4 message (second policy rule) to the UPF:

since the DDN Failure notification control indication information is included in the first N4 information or the acknowledgement message in step 213, the V-SMF may determine that the first N4 information is used to detect a downlink data notification Failure event;

the V-SMF determines second N4 information from the first N4 information. The method comprises the following specific steps:

when the V-SMF receives a UE unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR, and includes the same filter template and priority information as the first PDR. The V-SMF may determine an associated FAR according to the DDN Failure notification control indication information and the second PDR. The FAR is used to instruct the UPF to drop and report packets matching the second PDR.

When the V-SMF receives notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR from the first PDR, the second PDR being generated from the first PDR and including the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR and URR according to the DDN Failure notification control indication information and the second PDR. The FAR is used to instruct the UPF to discard the cached data matching the second PDR, and the URR is used to instruct the UPF to report when the cached data packet matching the second PDR is discarded.

Specifically, the process of generating the second PDR may be to directly use the first PDR as the second PDR, or the second PDR may be generated by other methods, for example, by performing format conversion on the first PDR, and the specific example is not limited herein.

The V-SMF sends second N4 information (N4 information) to the UPF, and the second N4 information comprises the second PDR, FAR and URR. In this embodiment of the present application, the second N4 information generated in the event subscription process may also be referred to as a second policy rule.

B: the message does not carry notification control indication information, and a corresponding policy rule is generated according to the subscription of the event, and the specific implementation mode is as follows:

208. the AMF sends a first message to the V-SMF:

and the AMF sends an Nsmf _ PDSUSessionUpdateSMContext Request message to the V-SMF and subscribes a downlink data notification failure event. In this embodiment, this message may also be referred to as a first message.

The message carries the NEF notification association identifier and the triplet information received in step 204.

209. The V-SMF returns an acknowledgement message to the AMF.

Specifically, the V-SMF sends an Nsmf _ pdusesion _ Update Request message to the second SMF, reports the received event subscription, and requests a policy for detecting data. The triple information and the Transaction identifier (Transaction Id) are carried in the message. In this embodiment, this message may also be referred to as a second message.

211. The second SMF sends a seventh message to the PCF:

212. PCF makes PCC rule, and sends third policy rule to second SMF:

And the second SMF determines first N4 information carrying the first PDR according to the PCC rule. The first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information and the transaction identifier. In this embodiment of the present application, the first N4 information generated in the event subscription process may also be referred to as a first policy rule.

214. The V-SMF sends a second N4 message (second policy rule) to the UPF:

since the V-SMF assigns a transaction id to the downlink data notification failure event in step 210, the V-SMF may associate the first N4 information in the message with the downlink data notification failure event subscription according to the transaction id in the message in step 213, and determine that the first N4 information is used to detect the downlink data notification failure event.

The V-SMF determines second N4 information according to the first N4 information and the subscription of the downlink data notification failure event. The method comprises the following specific steps:

when the V-SMF receives a UE unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR, and includes the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR from the downlink data notification failure event subscription and the second PDR.

When the V-SMF receives notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR from the first PDR, the second PDR being generated from the first PDR and including the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR and URR based on the downlink data notification failure event subscription and the second PDR. The FAR is used to instruct the UPF to discard the cached data matching the second PDR, and the URR is used to instruct the UPF to report when the cached data packet matching the second PDR is discarded.

215. UPF informs V-SMF that the matched packet is dropped:

under the condition that the UE is unreachable, the UPF matches a data packet according to the second PDR, discards the data packet matched with the second PDR according to the FAR, and then informs the V-SMF that the matched data packet is discarded; alternatively, the first and second electrodes may be,

and under the condition that the UE is in an idle state, the UPF matches the data packet according to the second PDR and caches the data packet matched with the second PDR according to the FAR. When the number of buffered packets exceeds a certain threshold, the UPF discards the data. At this point the V-SMF is notified according to the URR that the matched packet is discarded.

In this embodiment, the event of discarding data in step 215 may also be referred to as a second event, and the first SMF may determine the first event according to the second event. For example, in this embodiment, a downstream data transfer failure event may be determined according to the event of discarding data.

216. The V-SMF informs the AMF of the failure of the downlink data transmission:

after receiving the message that the data packet fed back by the UPF is discarded, the V-SMF may send an Nsmf _ pduse _ smcontextstatustnotify message to the AMF, and notify the AMF that the downlink data transmission fails.

The message includes the NEF notification association identifier that SMF received in step 208.

In this embodiment of the present application, the AMF may also be referred to as an event receiving network element, where the event receiving network element is configured to receive a report related to a first event, i.e. a report of a downlink data transfer failure event in this embodiment.

217. The AMF judges that the UE can reach:

if the UE still can not reach after the AMF receives the downlink data notification failure message of the V-SMF, the AMF sets a notification-on-available-after-DDN-failure (notify-on-available-after-DDN-failure) flag bit after the downlink data transmission failure.

When the AMF detects that the UE is reachable, the AMF may determine, according to the reachable notification flag after the downlink data transmission failure, that an reachable-DDN-failure event report needs to be sent after the downlink data transmission failure.

218. The AMF informs the NEF that the UE is reachable:

and the AMF sends an reachable event report after the transmission failure of the downlink data to the NEF. Specifically, the AMF may send a Namf _ EventExposure _ Notify Request message to the NEF, where the message carries the event identifier and the NEF notification endpoint received in step 204.

219. The NEF informs AF UE that the UE is reachable:

the NEF sends an Nnef _ EventExposure _ Notify Request message to the AF, where the message carries the event identifier and the AF notification endpoint received in step 203.

In an embodiment of the application, a first SMF (which may be a V-SMF or an I-SMF) requests a policy for detecting a downlink data state from the SMF, and the SMF further requests a PCC rule from the PCF. Thereby enabling detection of a packet of the subscription event by the first SMF.

In this embodiment, the second SMF may also initiate the request PCC rule and then send the N4 message to the first SMF (which may be a V-SMF or an I-SMF). The flow of the second SMF requesting the PCF for PCC rules and providing N4 information will now be described:

1.2, the second SMF requests the PCF for the PCC rule:

referring to fig. 3, when the UE is in the roaming state, the AF subscribes to an reachable event after the failure of downlink data transmission, and the second SMF requests the PCF for the PCC rule. For the scene that the PDU session has I-SMF, replacing V-SMF with I-SMF is enough. One process for providing policy rules in the embodiments of the present application includes:

301-307：

steps 301 to 307 are similar to steps 201 to 207 of the embodiment shown in fig. 2, and are not described again here.

308. AMF sends update context request message to V-SMF:

the AMF may generate downlink data notification failure (downlink data notification failure) notification indication information according to the subscription of the event in step 304, where the indication information is used to indicate that the event is reported when the downlink data notification failure event occurs.

And the AMF sends an Nsmf _ PDSUSessionUpdateSMContext Request message to the V-SMF and subscribes a downlink data notification failure event.

The message carries the NEF notification association identifier, the triplet information, and the downlink data notification failure notification indication information received in step 304. In this embodiment, the notification information of failure notification of downlink data notification may also be referred to as event subscription type indication information.

309. The V-SMF sends an update request message to the second SMF:

when V-SMF determines that data needs to be cached in UPF, V-SMF may determine that a PCC rule needs to be requested from PCF, at which point V-SMF may generate an indication that UPF caches data or an indication that PCC is requested.

And the V-SMF sends an Nsmf _ PDUSESSion _ Update Request message to the SMF, and subscribes a downlink data notification failure event.

The message carries the NEF notification association identifier, the triplet information, and the notification indication information of the downlink data notification failure (downlink data notification failure) received in step 308, as well as the indication of the above-mentioned UPF cache data or the indication of requesting the PCC.

310. The second SMF returns an acknowledgement message to the V-SMF:

311. V-SMF returns acknowledgement message to AMF:

there are two implementation ways for steps 312 to 315, which are as follows:

312. the second SMF determines that a policy rule for processing data needs to be requested, and sends an update request message to the PCF:

as an indication is received in step 309 that the UPF caches data or an indication to request a PCC, the second SMF may determine that a PCC rule needs to be requested from the PCF. And the PCF provides the PCRT carrying the data description for the failure event notification subscription, and the second SMF may send an Npcf _ SMPolicyControl _ Update request to the PCF to request a policy rule for processing data. The message carries the triplet information received in step 309 and the PCRT of the downlink data notification failure event subscription that carries the data description.

In this embodiment of the present application, the PCRT may also be referred to as event subscription type indication information, and in this embodiment of the present application, the event subscription type indication information is used to indicate a type of an event subscription.

In the embodiment of the present application, step 312 may also be performed before step 310 or 311, as long as it is performed after step 309, and is not limited herein.

313. PCF makes PCC rule, and sends third policy rule to second SMF:

the implementation manner of step 313 a is similar to that of step 212 a implemented in fig. 2, and is not described here again.

314. The second SMF receives the third policy rule, generates the first N4 message (N4 information), and sends the first policy rule to the V-SMF:

the second SMF receives the PCC rule (third policy rule) in step 313, and since the PCC rule is generated according to the triplet information in the message in step 312, and the triplet information is obtained together with the NEF notification association identifier when the update context request message is received in step 309, the second SMF may determine and store the correspondence between the NEF notification association identifier and the PCC rule identifier. When the subsequent failed subscription notification of the downlink data is updated or deleted, the PCC rule identifier corresponding to the event may be found according to the corresponding relationship, so as to send a corresponding instruction to the PCF, and enable the PCF to update or delete the PCC rule corresponding to the PCC rule identifier.

And the second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCC rule or the acknowledgment message in step 313 includes DDN Failure notification control indication information, so the first N4 information may also include DDN Failure notification control indication information, and the first PDR is determined according to the PCC rule and carries the same priority information and filter template as the PCC rule.

315. The V-SMF sends a second N4 message (second policy rule) to the UPF:

the implementation manner of step 315 is similar to that of step 214 implemented in fig. 2, and is not described here again.

since the PCF provides the PCRT with the data description carrying the failure event subscription for downlink data notification, the second SMF may send an Npcf _ SMPolicyControl _ Update request to the PCF to request a policy rule for processing data. The message carries the triplet information received in step 309 and the PCRT of the downlink data notification failure event subscription that carries the data description.

313. PCF makes PCC rule, and sends third policy rule to second SMF:

the implementation of step 313B is similar to the implementation of step 212B implemented in fig. 2, and is not described here again.

315. The V-SMF sends a second N4 message (second policy rule) to the UPF:

the implementation of step 315 is similar to the implementation of step 214 implemented in fig. 2, and is not described here again.

316-320：

Steps 316 to 320 are similar to steps 215 to 219 of the embodiment shown in fig. 2, and are not described again here.

In addition to subscribing to an event, the embodiment of the present application further provides updating and deleting of the event after the subscription is successful, and then a process of updating and deleting is described:

2. and (3) updating the reachable event after the downlink data notification fails:

in the embodiment of the present application, the data description information provided at the time of event update is referred to as second data description information. In this embodiment or the embodiment shown in fig. 4b, the data description information is the second data description information. The embodiment and the embodiment shown in fig. 4b take the triplet information as an example, and the triplet information does not limit the second data description information.

Referring to fig. 4a, based on the subscription of fig. 2 to the reachable event after the failure of the downlink data notification, in this embodiment, a process of obtaining a corresponding policy rule when updating the event is provided, and for a scenario in which a PDU session has an I-SMF, replacing the V-SMF with the I-SMF is sufficient, which is not specifically limited herein, and the process includes:

401a, accessing the network by the UE, establishing a PDU session:

at this point, the AF has already completed subscription to the reachable event after failure of downstream data notification according to the embodiment shown in fig. 2.

402a, AF sends a subscription request message to NEF:

the AF sends a Nnef _ EventExpo _ Subscribe Request message to the NEF, and requests to update the reachable (availability of downlink data notification failure) event subscription after the downlink data notification fails.

In this embodiment, the triplet information is used to replace the first data description information in the original subscription, and a policy rule corresponding to the triplet information is generated. In this embodiment or the implementation example shown in fig. 4b, the triplet information is also referred to as second data description information or second description information. The NEF subscription association identification is generated by the NEF during the event subscription.

403a, NEF sends subscription request message to UDM:

the NEF sends a Nudm _ EventExpo _ Subscribe Request message to the UDM, and requests to update the reachable event subscription after the downlink data notification fails.

The message carries the UDM subscription association identifier and the triplet information received in step 402 a. The UDM subscription association identification is generated by the UDM in the process of event subscription.

404a, the UDM sends a subscription request message to the AMF registered by the UE:

and the UDM sends a Namf _ EventExposure _ Subscripte Request message to the AMF registered by the UE, and requests to update the reachable event subscription after the downlink data notification fails.

The message carries the AMF subscription association identifier and the triple information. The AMF subscription association identification is generated in the process of event subscription by the AMF.

405a, AMF returns confirmation message to UDM:

the AMF updates the subscription information of the event according to the AMF subscription association identifier and the triple information received in step 404a, and returns a confirmation message to the UDM.

406a, UDM returns an acknowledgement message to NEF:

after receiving the acknowledgement message sent by the AMF, the UDM may update the subscription information of the event according to the UDM subscription association identifier and the triplet information received in step 403a, and return an acknowledgement message to the NEF.

407a, NEF returns confirmation message to AF:

after receiving the confirmation message sent by the UDM, the NEF may update the subscription information of the event according to the NEF subscription association identifier and the triplet information received in step 402a, and return a confirmation message to the AF.

In the embodiment of the present application, step 406a may also be performed before step 404a or step 405a, as long as it is performed after step 403 a; step 407a may also be performed before any of steps 403a to 406a, as long as it is performed after step 402a, and is not limited herein.

408a, AMF sends a third message to V-SMF:

and the AMF sends an Nsmf _ PDSUSessionUpdateSMContext Request message to the V-SMF to Request for updating the event subscription of the downlink data notification failure. In this embodiment, this message may also be referred to as a third message. In an embodiment of the application, the third message is used to request subscription of an update event from the V-SMF.

The message carries the NEF notification association identifier and the triple information. The NEF notification association identification is received during the event subscription process.

409a, V-SMF returns an acknowledgement message to AMF.

And the V-SMF updates the subscription information of the event according to the NEF notification association identifier and the triple information, and returns a confirmation message to the AMF.

There are two implementation ways for steps 410a to 414a, which are as follows:

410a, the V-SMF sends a fourth message to the second SMF:

in step 408a, when the V-SMF receives the third message, it may determine that the downlink data notification fails according to the NEF notification association identifier, and determine that the subscription of the event needs to be updated according to the message. In this embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, and is used to identify a subscription of the first event.

And the V-SMF sends an Nsmf _ PDSnessonUpdate Request message to the second SMF, wherein the message is used for requesting to Update the first N4 information. In this embodiment, this message may also be referred to as a fourth message. In this embodiment of the application, the fourth message is used to request the second SMF to update the policy rule for processing data corresponding to the subscription event.

The message carries triple information, transaction identification and DDN _ Failure indication information. The DDN _ Failure indication information, also referred to as event subscription type indication information, is generated during the event subscription, and indicates the type of the event subscription.

In the embodiment of the present application, the step 410a may also be performed before the step 409a, as long as it is performed after the step 408a, and is not limited herein.

411a, the second SMF sends an eighth message to the PCF:

in the event subscription process, the second SMF saves the correspondence between the transaction identifier and the PCC rule identifier, and at this time, the second SMF may determine the corresponding PCC rule identifier according to the transaction identifier.

And the second SMF sends an Npcf _ SMPolicyControl _ Update request message to the PCF, wherein the message is used for requesting to Update the PCC rule corresponding to the PCC rule identification. In this embodiment, this message may also be referred to as an eighth message. In this embodiment of the present application, the eighth message is used to request the PCF to update the PCC rule.

The message carries the triple information, the PCC rule identifier and the PCRT received in the event subscription process.

Optionally, the message may also carry an operation indication Modify, which indicates that the message is used to request an updated PCC rule.

412a, PCF updates PCC rule with triple information, and sends a fifth policy rule to the second SMF:

the PCF updates the PCC rule based on the triplet information, i.e. the triplet information is included in the filter template in the PCC rule. Optionally, the PCC rule may include DDN Failure notification control indication information. The DDN Failure notification control indication information is generated in the process of event subscription, and the PCF can determine the indication information through the corresponding relation between the indication information and the PCC rule identifier; the DDN Failure notification control instruction information may be generated by the PCF according to the DDN _ Failure instruction information, and is not limited herein.

And the PCF returns a confirmation message to the second SMF, wherein the message carries the updated PCC rule. In this embodiment of the present application, the PCC rule generated in the event subscription process may also be referred to as a third policy rule.

Optionally, the DDN Failure notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

413a, the second SMF updates the first N4 information (N4 information), and sends a fourth policy rule to the V-SMF:

and the second SMF updates the first N4 information carrying the first PDR according to the PCC rule. The first N4 information further includes DDN Failure notification control indication information, and the first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information. Optionally, the DDN Failure notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

414a, the V-SMF sends the UPF a second N4 message:

since the DDN Failure notification control indication information is included in the first N4 information or the acknowledgement message in step 413a, the V-SMF determines that the first N4 information is used to detect a downlink data Failure notification event. The V-SMF determines second N4 information from the first N4 information.

410a, V-SMF determines that it needs to request updating of policy rules for processing data, and sends a fourth message to the second SMF:

in step 408a, when the V-SMF receives the third message, it may determine a downlink data notification failure event according to the NEF notification association identifier in the third message, and determine that the subscription of the event needs to be updated according to the message. In this embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, and is used to identify a subscription of the first event.

And the V-SMF sends an Nsmf _ PDSnessonUpdate Request message to the second SMF, wherein the message is used for requesting to Update the first N4 information. In this embodiment, this message may also be referred to as a fourth message. The triple information and the transaction identifier are carried in the message. The transaction identifier is generated during event subscription, and is used to represent an event between the first SMF and the second SMF, specifically, in this embodiment, corresponds to subscription of a downlink data notification failure event.

411a, the second SMF sends an eighth message to the PCF:

And the second SMF sends an Npcf _ SMPolicyControl _ Update request message to the PCF, wherein the message is used for requesting to Update the PCC rule corresponding to the PCC rule identification. In this embodiment, this message may also be referred to as an eighth message.

The message carries the triple information and the PCC rule identification. Optionally, the message may carry a PCRT.

the PCF updates the PCC rule based on the triplet information, i.e. the triplet information is included in the filter template in the PCC rule.

And the PCF returns a confirmation message to the second SMF, wherein the message carries the updated PCC rule. In this embodiment of the present application, the PCC rule generated in the event update process may also be referred to as a fifth policy rule.

and the second SMF updates the first N4 information carrying the first PDR according to the PCC rule. The first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

In step 412a, the PCC rule received by the second SMF includes a PCC rule identifier, and since the second SMF stores the correspondence between the PCC rule identifier and the transaction identifier during subscription, the second SMF may determine the transaction identifier corresponding to the PCC rule according to the PCC rule identifier.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information and the transaction identifier. In the embodiment of the present application, the first N4 information generated in the event updating process may also be referred to as a fourth policy rule.

414a, the V-SMF sends the UPF a second N4 message:

the V-SMF may associate the first N4 information with a downstream data notification failure event subscription according to the transaction identification received in step 413a, and determine that the first N4 information is used for detecting a downstream data notification failure event. And the V-SMF determines second N4 information according to the first N4 information and the subscription of the downlink data failure notification event.

415a-149a：

Steps 415a to 419a are similar to steps 215 to 219 of the embodiment of fig. 2, and are not repeated here.

Referring to fig. 4b, based on the subscription of fig. 3 to the reachable event after the failure of the downlink data notification, in this embodiment, a process of obtaining a corresponding policy rule when updating the event is provided, and for a scenario in which the PDU session has an I-SMF, replacing the V-SMF with the I-SMF is sufficient, which is not specifically limited herein, and the process includes:

401b, the UE accesses the network, establishes a PDU session:

at this point the AF has completed subscription to reachable events after failure of downstream data notification according to the embodiment shown in fig. 3.

402b-407b:

Steps 402b to 407b are similar to steps 402a to 407a of the example of fig. 4a, and are not repeated here.

In the embodiment of the present application, step 406b may also be performed before step 404b or step 405b, as long as it is performed after step 403 b; step 407b may also be performed before any of steps 403b to 406b, as long as it is performed after step 402b, and is not limited herein.

408b, AMF sends an update context request message to V-SMF:

and the AMF sends an Nsmf _ PDSUSessionUpdateSMContext Request message to the V-SMF to Request for updating the event subscription of the downlink data notification failure.

The message carries the NEF notification association identifier and the triple information. The NEF notification association identification is received during the event subscription.

409b, the V-SMF sends an update request message to the second SMF:

and the V-SMF sends an Nsmf _ PDUSESSion _ Update Request message to the second SMF to Request for updating the event subscription of which the downlink data notification fails.

The message carries the NEF notification association identifier and the triple information.

410b, the second SMF returns an acknowledgement message to the V-SMF.

411b, V-SMF returns an acknowledgement message to AMF.

There are two implementation ways for steps 412b to 415b, which are as follows:

412b, the second SMF determines that it needs to request updating of policy rules for processing data, and sends the updated triplet information to the PCF:

in step 409b, the second SMF receives the update request message, may determine a downlink data notification failure event according to the NEF notification association identifier in the message, and determine that the subscription of the event needs to be updated according to the message. In this embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, and is used to identify a subscription of the first event.

In the event subscription process, the second SMF saves the correspondence between the NEF notification association identifier and the PCC rule identifier, and the NEF notification association identifier corresponds to the subscription of the event, at this time, the second SMF may determine the PCC rule identifier corresponding to the event subscription.

And the second SMF sends an Npcf _ SMPolicyControl _ Update request message to the PCF, wherein the message is used for requesting to Update the PCC rule corresponding to the PCC rule identification.

The message carries the triple information and the PCC rule identification. And DDN Failure indication information. The DDN Failure indication information is also referred to as event subscription type indication information, and is generated in the event subscription process, and is used for indicating the type of the event subscription.

In the embodiment of the present application, the step 412b may also be performed before the step 410b or 411b, as long as the step is performed after the step 409b, and is not limited herein.

413b-415b：

The implementation manner of step 413b to step 415b is similar to the implementation manner of step 412a to step 414a in the embodiment of fig. 4a, and is not described herein again.

In the event subscription process, the second SMF saves the corresponding relationship between the transaction identifier and the PCC rule identifier, and the transaction identifier corresponds to the event subscription, at this time, the second SMF may determine the PCC rule identifier corresponding to the event subscription.

The message carries the triple information and the PCC rule identification.

Optionally, the PCRT may be carried in the message.

413b-415b：

The implementation of step 413B to step 415B is similar to the implementation of step 412a to step 414a in the example of fig. 4a, and is not described herein again.

416b-420b：

Steps 416b to 420b are similar to steps 415a to 419a of the example of fig. 4a, and are not repeated here.

In the embodiments shown in fig. 4a and 4b, the first SMF, the second SMF, and the PCF updates the PCC rule, the first PDR, the second PDR, the FAR and the URR related to the subscription event to the corresponding policy rule generated according to the second data description information according to the event subscription type indication information and the notification control indication information, or the association relationship between the data description information identifier, the PCC rule identifier, and the subscription event, thereby implementing the update of the policy rule of the event.

3. And deleting the reachable events after the downlink data notification fails:

referring to fig. 5a, based on the subscription of fig. 2 to the reachable event after the failure of the downlink data notification, in this embodiment, a process of deleting the event subscription is provided, and for a scenario in which the PDU session has an I-SMF, the V-SMF is replaced by the I-SMF, which is not limited herein specifically, the process includes:

501a, accessing the network by the UE, establishing a PDU session:

this is consistent with step 401a in the example of fig. 4a, and is not described here again.

502a, AF sends unsubscribe request message to NEF:

and the AF sends a message of Nnef _ EventExposure _ Unscubscripte Request to the NEF to Request to delete the subscription of the reachable event after the transmission of the downlink data fails.

The message carries the NEF subscription association identifier received in the event subscription process.

503a, NEF sends a subscription request message to UDM:

the NEF sends a Nudm _ EventExpo _ Unscubscribe Request message to the UDM to Request to delete the subscription of the reachable event after the transmission of the downlink data fails.

The message carries the UDM subscription association identifier received in the event subscription process.

504a, UDM sends subscription request message to AMF registered by UE:

and the UDM sends a Namf _ EventExposure _ Unscubscripte Request message to the AMF registered by the UE to Request to delete the subscription of the reachable event after the transmission failure of the downlink data.

The message carries the AMF subscription association identifier received in the event subscription process.

505a, the AMF returns an acknowledgement message to the UDM.

506a, UDM returns an acknowledgement message to NEF.

507a, NEF returns confirmation message to AF.

508a, AMF sends a fifth message to V-SMF:

and the AMF sends an Nsmf _ PDUSESION _ UpdateSMContext Request message to the V-SMF to Request to delete the downlink data and notify a failure event.

The message carries a unsubscribe instruction and a NEF Notification association identifier (Notification Correlation Id) received in the event subscription process.

In the embodiment of the present application, step 506a may also be performed before step 504a or step 505a, as long as it is performed after step 503 a; step 507a may also be performed before any of steps 503a to 506a, as long as it is performed after step 502 a; step 508a may also be performed before any of steps 505a to 507a, as long as it is performed after step 504a, and is not limited herein.

509a, V-SMF returns an acknowledgement message to AMF.

510a, V-SMF determines that it is required to request deletion of the first N4 message, and sends a sixth message to the second SMF:

V-SMF may determine that deletion of the first N4 message is required by determining that a downstream data delivery failure event is required according to the NEF notification association flag in step 508a and determining that the subscription of the event needs to be deleted according to the unsubscribe indication. In this embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, and is used to identify a subscription of the first event.

In the process of subscription, the V-SMF stores the corresponding relationship between the event subscription and the transaction identifier, and at this time, the transaction identifier corresponding to the event subscription can be queried.

Specifically, the V-SMF sends an Nsmf _ pdusesion _ Update Request message to the SMF, where the message carries an indication requesting deletion of the first N4 information. In the present embodiment, this message is also referred to as a sixth message for requesting deletion of the first N4 information.

The message carries the transaction identifier and the operation indication delete.

In the embodiment of the present application, the step 510a may also be performed before the step 509a, as long as it is performed after the step 508a, which is not limited herein.

511a, the second SMF sends a ninth message to the PCF:

The second SMF sends an Npcf _ SMPolicyControl _ Update request to the PCF requesting deletion of the PCC rule.

The message carries PCC rule identification and operation indication delete.

512a, PCF deletes PCC rule and returns confirmation message to SMF:

the PCF may delete the PCC rule corresponding to the PCC rule identity according to the PCC rule identity received in step 511 a.

The PCF returns a confirmation message to the second SMF, where the message carries an indication to delete the PCC rule corresponding to the PCC rule identifier, and specifically, the message may include the PCC rule identifier and the deletion indication.

513a, the second SMF deletes the first N4 information and sends an indication to the V-SMF to delete the first N4 information:

and the second SMF deletes the first N4 information locally stored in the second SMF according to the deleted PCC rule identification, and sends an indication of deleting the first N4 information to the V-SMF.

514a, V-SMF and UPF to delete corresponding PDR, FAR and URR.

And the V-SMF determines that the second N4 information needs to be deleted according to the received indication of deleting the first N4 information, and the V-SMF and the UPF interactively delete the PDR, FAR and URR corresponding to the second N4 information.

Referring to fig. 5b, based on the subscription of fig. 3 to the reachable event after the failure of the downlink data notification, in this embodiment, a process of deleting the event subscription is provided, and for a scenario in which the PDU session has an I-SMF, the V-SMF is replaced by the I-SMF, which is not limited herein specifically, the process includes:

501b, accessing the network by the UE, establishing a PDU session:

502b-507b：

Steps 502b to 507b are similar to steps 502a to 507a of the example of fig. 5a, and are not repeated here.

508b, AMF sends update context request message to V-SMF:

The message carries the unsubscribe indication and the received NEF notification association identifier in the event subscription process.

509b, the V-SMF sends an update request message to the second SMF:

and the V-SMF sends an Nsmf _ PDUSESSion _ Update Request message to the second SMF to Request to delete the downlink data and notify a failure event.

The message carries the NEF notification association identifier and the unsubscribe indication.

It should be noted that the unsubscribe indication in step 509b may be generated according to the unsubscribe indication in step 508b, or is the unsubscribe indication in step 508b, which is not limited herein.

510b, the second SMF returns an acknowledgement message to the V-SMF.

511b, the V-SMF returns an acknowledgement message to the AMF.

512b, the second SMF determines that it needs to request to delete the policy rule for processing data, and sends a request to the PCF to delete the PCC rule:

in step 509b, the second SMF receives the update request message, and the second SMF may determine the downlink data delivery failure event according to the NEF notification association identifier in the request, and determine that the subscription of the event needs to be deleted according to the unsubscribe indication, thereby determining that the PCC rule needs to be requested to be deleted. In this embodiment of the present application, the NEF notification association identifier may also be referred to as a third identifier, and is used to identify a subscription of the first event.

The message carries PCC rule identification and operation indication delete.

In the embodiment of the present application, the step 512b may also be performed before the step 510b or 511b, as long as it is performed after the step 509b, which is not limited herein.

513b-515b：

Steps 513b to 515b are similar to steps 512a to 514a of the example of fig. 5a, and are not repeated here.

In the embodiments shown in fig. 5a and 5b, the first SMF, the second SMF, and the PCF deletes the policy rules related to the event subscription, such as the PCC rule, the first PDR, the second PDR, the FAR, and the URR, according to the association relationship among the data description information identifier, the PCC rule identifier, and the subscription event, thereby deleting the policy rules of the event.

It is to be noted that, in this embodiment of the present application, the event identifier may also be an identifier of another event, for example, a downlink data transfer state event, where different event identifiers represent different subscription events, and accordingly different PCC rules and policy rules may be generated, and the network element may also correspondingly perform different operations, which is not limited herein.

The following illustrates the process of providing policy rules for a network, which are policy rules for downstream data delivery status events. In this embodiment, the downlink data delivery status event may also be referred to as a downlink data transmission status event or a downlink data notification status event, and in this embodiment, this event is also referred to as a first event.

Obtaining a strategy rule of a downlink data transmission state event:

1. subscribing to a downstream data delivery state event:

referring to fig. 6, when the UE is in roaming state, i.e. the V-SMF cannot directly interact with the PCF, the AF subscribes to a downlink data delivery state event, and the first SMF requests the PCF for a PCC rule. For the scenario that the PDU session has I-SMF, the V-SMF may be replaced by I-SMF, which is not limited herein. One process for providing policy rules in the embodiments of the present application includes:

601. UE accesses to the network and establishes PDU conversation:

Optionally, during the PDU session establishment or modification process, the PCF may send a Policy Control Request Trigger (PCRT) to the second SMF, where the trigger is a downlink data delivery status event subscription (downlink data delivery status event with traffic descriptor) carrying a data description. The PCRF is used for indicating the second SMF to request the PCC rule from the PCF when receiving the subscription of the downlink data transmission state event carrying the data description.

In the embodiment of the present application, the PCRT is also referred to as a downlink data notification event subscription trigger.

602. The AF sends a subscription request message to the NEF:

the AF sends an Nnef _ EventExposure _ Subscribe Request message to the NEF, subscribing to a downlink data delivery status (downlink data delivery status) event.

The message carries an event identifier (event id), an AF notification endpoint (AF notification endpoint), triple information, an external identifier of the user or an external user group identifier, and a discarded delivery status.

In this embodiment of the present application, in addition to the discarded delivery status, the subscribed delivery status may also be cached or transmitted, and this embodiment takes the discarded delivery status as an example, and does not cause a limitation to the subscribed delivery status.

In the embodiment of the present application, the data description information provided at the time of event subscription is referred to as first data description information, and the data description information provided at the time of event update is referred to as second data description information. In this embodiment or the embodiment shown in fig. 7, the data description information is the first data description information.

The event identifier (event id) represents a subscribed event, and in this embodiment, is an identifier of a downstream data transfer state event.

603. NEF sends subscription request message to UDM:

the NEF sends a nutm _ EventExposure _ Subscribe Request message to the UDM, subscribing to downstream data delivery status events.

The message carries the event identifier, the triple information, the discarded delivery status, the external identifier of the user or the external user group identifier received in step 602, and an NEF notification endpoint (NEF notification endpoint) where the NEF is configured to receive the subscription notification.

The NEF notification endpoint is used to indicate an endpoint used by the NEF to receive the subscription notification, and may include a NEF notification target address (NEF notification target address) and a NEF notification association identification (NEF notification correlation Id). When the NEF assigns the same NEF notification target address to a plurality of subscription notifications, different events can be distinguished by the NEF notification association identification.

604. The UDM sends a subscription request message to the second SMF registered by the UE:

the UDM, having received the external identity of the user in step 603, can determine the internal identity of the user based on the external identity.

In this embodiment of the application, when the event subscription is directed to multiple users, the external identifier of the user in steps 602 and 603 may also be an external user group identifier, where the external user group identifier represents each of the users, and at this time, the internal identifier of each of the users may be determined according to the external user group identifier, which is not limited herein.

The UDM may determine the second SMF registered by the UE according to the locally stored correspondence and the user internal identifier, and send an Nsmf _ EventExposure _ Subscribe Request message to the second SMF registered by the UE, subscribing to the downlink data delivery status event.

The message carries the event identifier, triplet information, NEF notification endpoint, discarded delivery status, and the user internal identifier received in step 203.

If the user group identifier is received in step 603, the UDM may send the message to the second SMF registered to the UE for each UE in the user group.

605. The second SMF sends a first message to the V-SMF:

and the second SMF sends an Nsmf _ EventExpo _ Subscribe Request message to the V-SMF registered by the UE and subscribes to the downlink data transfer state event. In this embodiment, this message may also be referred to as a first message;

the message carries the event identifier, the NEF notification association identifier, the triplet information, the discarded delivery status, and the user internal identifier received in step 604.

If the user group identity is received in step 604, the second SMF may send the message to the V-SMF registered by the UE for each UE in the user group.

606. The V-SMF returns an acknowledgement message to the second SMF:

the V-SMF assigns an SMF subscription association identifier (SMF subscription association id) according to the event identifier received in step 605, where the SMF subscription association identifier is used to identify a downstream data delivery status event, and indicates that the event is successfully subscribed at the V-SMF.

And the V-SMF stores the received information and returns a confirmation message to the second SMF, wherein the message carries the SMF subscription related identification.

607. The second SMF returns an acknowledgement message to the UDM:

the second SMF assigns an SMF subscription association identifier (SMF subscription association id) according to the event identifier received in step 604, where the SMF subscription association identifier is used to identify the downstream data delivery status event, and indicates that the event has been subscribed successfully at the second SMF.

And the second SMF stores the received information and returns a confirmation message to the UDM, wherein the message carries the SMF subscription related identification.

Step 607 may also be performed before step 605 or 606 as long as it is performed after step 603.

608. The UDM returns an acknowledgement message to the NEF:

the UDM assigns a UDM subscription association id (UDM subscription association id) to the event subscription, and the UDM subscription association id is used to identify a downstream data delivery status event, which indicates that the event has been successfully subscribed at the UDM.

609. The NEF returns an acknowledgement message to the AF:

the NEF assigns a NEF subscription association identifier (NEF subscription correlation id) to the event subscription, where the NEF subscription association identifier is used to identify a downstream data delivery status event and indicate that the event subscription is successfully subscribed at the NEF.

In the embodiment of the present application, step 608 may be performed before any of steps 604 to 607 as long as it is performed after step 603; step 609 may be performed before any of steps 603 to 608 as long as it is performed after step 602, and is not limited herein.

There are two implementation manners of steps 610 to 614, which are as follows:

610. the V-SMF determines that a policy rule for processing data needs to be requested, and sends a second message to a second SMF:

in step 601, the V-SMF receives indication information that policy charging control is applied to the UE, indication information that downlink data delivery status event subscription is reported to be received, or indication information that data description information is reported to be received, and the V-SMF may determine that PCC is applied to the PDU session, and when the V-SMF determines that data needs to be cached in the UPF, may also determine that the received event subscription needs to be reported to a second SMF and request a policy for processing the data in the UPF.

The V-SMF may assign a Transaction identification (Transaction Id) to the event, which is used to represent a Transaction between the V-SMF and a second SMF for subsequent modify and delete operations. In the embodiment of the present application, the transaction identifier may also be referred to as first identification information. In an embodiment of the present application, the transaction identifier corresponds to a subscription of the first event, and the transaction identifier may also be used to identify a policy rule request for the subscription of the first event. In this embodiment, the transaction identifier corresponds to a subscription of the downstream data delivery state event.

The V-SMF may also allocate downlink data delivery status indication information according to the subscription of the event in step 605, where the downlink data delivery status indication information is used to indicate that the received event subscription type is a downlink data delivery status subscription.

The downlink data delivery status indication information is also referred to as event subscription type indication information in this embodiment, and is used to indicate a type of event subscription. In the embodiment of the application, the event subscription type indication information is generated according to the subscription of the event.

Specifically, the V-SMF sends an Nsmf _ pdusesion _ Update Request message to the second SMF, reports the received event subscription, and requests a policy for detecting data. The message carries triple information, the Transaction identifier (Transaction Id) and the downlink data transmission status indication information. In this embodiment, this message may also be referred to as a second message.

611. The second SMF sends a seventh message to the PCF:

After receiving the transaction identifier, the second SMF needs to request the PCF for the reachable PCC rule after the failure of the downlink data transfer, and since the PCF provides the PCRT carrying the subscription of the downlink data transfer state event described by the data, the second SMF may send an Npcf _ SMPolicyControl _ Update request message to the PCF. In this embodiment, this message may also be referred to as a seventh message. In this embodiment of the present application, the seventh message is used to request the PCC rule from the PCF.

The second SMF determines, according to the downlink data transfer state indication information in the second message, that the message is used to request a PCC rule for detecting a downlink data transfer state event, and the second SMF may find the PCRT corresponding to the event received in step 601.

The message carries the triplet information and the downlink data transmission status indication information received in step 610, and the PCRT.

612. PCF makes PCC rule, and sends third policy rule to second SMF:

the PCF formulates a PCC rule (PCC rule) according to the triplet information received in step 611, that is, a filter template in the PCC rule includes the triplet information, and sets a high priority, where the PCC rule includes a PCC rule identifier (PCC rule Id), and the PCC rule identifier is used to represent the PCC rule, and when the PCC rule is subsequently updated or deleted, the corresponding PCC rule may be determined according to the PCC rule identifier, so as to change the PCC rule. In the embodiment of the present application, the PCC rule identification may also be referred to as second identification information.

The PCF may also determine downlink data delivery status notification control indication information according to the PCRT received in step 611, where the downlink data delivery status notification control indication information is used to indicate that downlink data delivery status notification needs to be performed. The downlink data delivery status notification control indication information may be included in the PCC rule, and is used to indicate that the PCC rule is used to detect a downlink data delivery status event.

The downlink data transfer state notification control indication information is also referred to as notification control indication information in this embodiment.

Optionally, the downlink data transfer state notification control indication information may also be carried in the acknowledgement message instead of being included in the PCC rule, and is not limited herein.

613. The second SMF receives the third policy rule, generates the first N4 message (N4 information), and sends the first policy rule to the V-SMF:

when the second SMF receives the PCC rule (third policy rule) of step 612, since the second message in step 610 includes the triplet information and the transaction identifier at the same time, and the PCC rule is generated according to the triplet information, the second SMF may determine and store the corresponding relationship between the transaction identifier and the PCC rule identifier accordingly. When the subsequent downlink data delivery state subscription is updated or deleted, the PCC rule identifier corresponding to the event can be found according to the corresponding relationship, so as to send a corresponding instruction to the PCF, and enable the PCF to update or delete the PCC rule corresponding to the PCC rule identifier.

And the second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCC rule or the acknowledgment message in step 612 includes downlink data delivery status notification control indication information, so the first N4 information may also include downlink data delivery status notification control indication information, and the first PDR is determined according to the PCC rule and carries the same priority information and filter template as the PCC rule.

Optionally, the downlink data transfer state notification control indication information may not be included in the first N4 information, but is carried in the acknowledgement message, which is not limited herein.

614. The V-SMF sends a second N4 message (second policy rule) to the UPF:

since the first N4 information or the acknowledgement message in step 613 includes the downstream data transfer state notification control indication information, the V-SMF may determine that the first N4 information is used to detect the downstream data transfer state event;

When the subscribed delivery status is cached, the FAR is used to instruct the UPF to cache the packet matching the PDR, and the URR is used to instruct the UPF to notify the SMF when caching the packet, which is not limited herein.

611. The second SMF sends a seventh message to the PCF:

The triplet information and the PCRT received in step 610 are carried in the message.

612. PCF makes PCC rule, and sends third policy rule to second SMF:

614. The V-SMF sends a second N4 message (second policy rule) to the UPF:

since the V-SMF assigns a transaction id to the downstream data delivery status event in step 610, the V-SMF may associate the first N4 information in the message with the downstream data delivery status event subscription according to the transaction id in the message in step 613, and determine that the first N4 information is used to detect the downstream data delivery status event.

The V-SMF determines second N4 information according to the first N4 information and the downstream data delivery state event subscription. The method comprises the following specific steps:

when the V-SMF receives a UE unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR, and includes the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR based on the subscription to the downstream data delivery state event and the second PDR. The FAR is used to instruct the UPF to drop and report packets matching the second PDR.

When the V-SMF receives notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR from the first PDR, the second PDR being generated from the first PDR and including the same filter template and priority information as the first PDR. The V-SMF may determine the associated FAR and URR based on the subscription to the downstream data delivery state event and the second PDR. The FAR is used to instruct the UPF to discard the cached data matching the second PDR, and the URR is used to instruct the UPF to report when the cached data packet matching the second PDR is discarded.

615. UPF informs V-SMF that the matched packet is dropped:

and after discarding the data packet matched with the PDR by the UPF according to the FAR, informing the V-SMF to discard the data packet matched with the PDR according to the URR.

When the transmission state is the cache, the UPF caches the data packet matched with the PDR according to the FAR, and then informs the V-SMF that the matched data packet is cached according to the URR.

616. V-SMF sends notification request message to NEF:

when the V-SMF receives the notification that the packet sent by the UPF is dropped, the V-SMF may send the notification that the packet is dropped to the NEF.

When the transmission state is buffering, and the V-SMF receives a notification that the packet sent by the UPF is buffered, the V-SMF may send the notification that the packet is buffered to the NEF.

When the transmission state is transfer, when the V-SMF detects that the PDU session becomes ACTIVE, that is, it is confirmed that the UE is reachable, and receives the notification that the packet is buffered in step 615, the UPF will automatically forward the previously buffered data, and at this time, the V-SMF may determine that the previously buffered packet is transferred, and send the notification that the packet is transferred to the NEF.

Optionally, the V-SMF may send the notification to the second SMF first, and then the second SMF reports to the NEF, which is not limited herein.

In this embodiment, the event of discarding data or caching data in step 615 may also be referred to as a second event, and the first SMF may determine the first event according to the second event. For example, in this embodiment, the downstream data delivery status event may be determined according to an event of discarding data or buffering data.

In this embodiment, the NEF may also be referred to as an event receiving network element, and the event receiving network element is configured to receive a report related to the first event, which is a report of the downlink data transfer status event in this embodiment.

617. The NEF sends a notification request message to the AF:

the NEF sends an Nneff _ EventExposure _ Notify Request message to the AF, and the message carries an event identifier and an AF notification endpoint.

In this embodiment of the present application, the PCC rule may be requested by not only the first SMF, but also the second SMF, and a flow of requesting the PCC rule from the PCF by the second SMF will be described below:

1.2, the second SMF requests the PCF for the PCC rule:

referring to fig. 7, when the UE is in roaming state, the AF subscribes to a downlink data delivery state event, and the second SMF requests the PCC rule from the PCF. For the scene that the PDU session has I-SMF, replacing V-SMF with I-SMF is enough. One process for providing policy rules in the embodiments of the present application includes:

701-705：

steps 701 to 705 are similar to steps 601 to 605 of the embodiment shown in fig. 6, and are not described again here.

706. The V-SMF returns an acknowledgement message to the second SMF:

the V-SMF allocates an SMF subscription association identifier (SMF subscription association id) according to the event identifier received in step 705, where the SMF subscription association identifier is used to identify a downstream data delivery status event, and indicates that the event has been subscribed successfully at the V-SMF.

The V-SMF determines that the data is cached by the UPF, the V-SMF may generate an indication that the UPF caches the data or an indication that the PCC is requested.

And the V-SMF stores the received information and returns a confirmation message to the second SMF, wherein the message carries the SMF subscription related identification and the UPF cache data indication or PCC request indication.

707-709：

Steps 707 to 709 are similar to steps 607 to 609 of the embodiment shown in fig. 6, and are not described herein again.

In the embodiment of the present application, step 707 may also be executed before step 705 or 706 as long as it is executed after step 704; step 708 may also be performed before any step between steps 704 to 707, as long as it is performed after step 703; step 709 may also be executed before any step between steps 703 and 708, as long as it is executed after step 702, and is not limited herein.

There are two implementation ways for steps 710 to 713, which are as follows:

710. the second SMF determines that a policy rule for processing data needs to be requested, and sends an update request message to the PCF:

as an indication is received in step 706 that the UPF caches data or an indication to request a PCC, the second SMF may determine that a PCC rule needs to be requested from the PCF. And the PCF provides the PCRT carrying the subscription of the downlink data delivery state event described by the data, and the second SMF may send an Npcf _ SMPolicyControl _ Update request to the PCF to request a policy rule for processing the data.

The message carries the triplet information received in step 704 and the PCRT carrying the downlink data delivery state event subscription described by the data.

In this embodiment of the present application, the PCRT may also be referred to as event subscription type indication information, where the event subscription type indication information is used to indicate a type of an event subscription.

In the embodiment of the present application, the step 710 may also be performed before any step between the steps 707 to 709, as long as the step is performed after the step 706, and is not limited herein.

711. PCF makes PCC rule, and sends third policy rule to second SMF:

the implementation manner of step 711 is similar to the implementation manner of step 612 implemented in fig. 6, and is not described here again.

712. The second SMF receives the third policy rule, generates the first N4 message (N4 information), and sends the first policy rule to the V-SMF:

the second SMF receives the PCC rule (third policy rule) in step 711, and since the PCC rule is generated according to the triplet information in the message in step 710, and the triplet information is associated with the subscription of the downlink data delivery state event, and the second SMF assigns an SMF subscription association identifier to the subscription of the event, the second SMF may determine and store the correspondence between the SMF subscription association identifier and the PCC rule identifier. When the subsequent failed subscription notification of the downlink data is updated or deleted, the PCC rule identifier corresponding to the event may be found according to the corresponding relationship, so as to send a corresponding instruction to the PCF, and enable the PCF to update or delete the PCC rule corresponding to the PCC rule identifier.

And the second SMF determines first N4 information carrying the first PDR according to the PCC rule. The PCC rule or the confirmation message in step 711 includes a PCRT, so the first N4 information may also include the PCRT, and the first PDR is determined according to the PCC rule and carries the same priority information and filter template as the PCC rule.

Optionally, the PCRT may not be included in the first N4 message, but is carried in the acknowledgement message, which is not limited herein.

713. The V-SMF sends a second N4 message (second policy rule) to the UPF:

the implementation manner of step 713 a is similar to the implementation manner of step 614 a implemented in fig. 6, and is not described here again.

711. PCF makes PCC rule, and sends third policy rule to second SMF:

the implementation of step 711 in B is similar to that of step 612 in the example implemented in fig. 6, and is not described here again.

the second SMF receives the PCC rule (third policy rule) in step 711, and since the PCC rule is generated according to the triplet information in the message in step 710, and the triplet information is associated with the subscription of the downlink data transmission state event, and the second SMF assigns an SMF subscription association identifier to the subscription of the event, the second SMF may determine and store the correspondence between the SMF subscription association identifier and the PCC rule identifier. When the subsequent failed subscription notification of the downlink data is updated or deleted, the PCC rule identifier corresponding to the event may be found according to the corresponding relationship, so as to send a corresponding instruction to the PCF, and enable the PCF to update or delete the PCC rule corresponding to the PCC rule identifier.

713. The V-SMF sends a second N4 message (second policy rule) to the UPF:

the implementation of step 713B is similar to the implementation of step 614B in the example of fig. 6, and is not described here again.

714-716：

Steps 714 to 716 are similar to steps 615 to 617 in the embodiment shown in fig. 6, and are not described herein again.

2. updating downlink data transmission state events:

referring to fig. 8a, based on the subscription of fig. 6 to the downlink data transmission status event, in this embodiment, a process of obtaining a corresponding policy rule when updating the event is provided, and for a scenario in which a PDU session has an I-SMF, the V-SMF may be replaced by the I-SMF, which is not limited herein specifically, and the process includes:

801a, UE accesses a network, establishes a PDU session:

at this point the AF has completed subscription to the downstream data transmission state event according to the embodiment shown in fig. 6.

802a, AF sends a subscription request message to NEF:

the AF sends an Nnef _ EventExposure _ Subscribe Request message to the NEF requesting an update of a downstream data delivery status (downlink data delivery status) event subscription.

In this embodiment, the triplet information is used to replace the original triplet information in the subscription, and a policy rule corresponding to the triplet information is generated. In this embodiment or the implementation example shown in fig. 8b, the triplet information is also referred to as second data description information or second description information. The NEF subscription association identification is generated by the NEF during the event subscription.

803a, NEF sends a subscription request message to UDM:

the NEF sends a nutm _ EventExposure _ Subscribe Request message to the UDM requesting an update of the downstream data delivery state event subscription.

The message carries the UDM subscription association identifier and the triplet information received in step 802 a. The UDM subscription association identification is generated by the UDM in the process of event subscription.

804a, the UDM sends a subscription request message to the second SMF:

the UDM sends a Namf _ EventExposure _ Subscribe Request message to the second SMF requesting an update of the downstream data transfer state event.

The message carries the SMF subscription association identifier and the triplet information received in step 803. The SMF subscription association identity is the same as that assigned by the second SMF in step 607 in the embodiment shown in fig. 6.

805a, the second SMF sends a third message to the V-SMF registered by the UE:

and the second SMF sends a Namf _ EventExposure _ SubscribeRequest message to the V-SMF registered by the UE to Request to update the downlink data transmission state event. In this embodiment, this message may also be referred to as a third message. In an embodiment of the application, the third message is used to request subscription of an update event from the V-SMF.

The message carries the SMF subscription association identifier and the triplet information received in step 804. The SMF subscription association identity is assigned by the V-SMF at event subscription.

806a, V-SMF returns an acknowledgement message to the second SMF:

and the V-SMF determines that the subscription event is a downlink data transmission state event according to the SMF subscription association identifier received in step 805a, updates the subscription information of the event according to the triplet information, and returns a confirmation message to the second SMF.

807a, the second SMF returns an acknowledgement message to the UDM:

after receiving the confirmation message sent by the V-SMF, the second SMF determines that the subscription event is a downlink data transmission state event according to the SMF subscription association identifier received in step 804a, updates the subscription information of the event according to the triplet information, and returns a confirmation message to the UDM.

808a, the UDM returns an acknowledgement message to the NEF:

after receiving the confirmation message sent by the second SMF, the UDM determines that the subscription event is a downlink data transmission state event according to the UDM subscription association identifier received in step 803, updates the subscription information of the event according to the triplet information, and returns a confirmation message to the NEF.

809a, NEF returns confirmation message to AF:

after receiving the confirmation message sent by the UDM, the NEF determines that the subscription event is a downlink data transmission state event according to the NEF subscription association identifier received in step 802a, updates the subscription information of the event according to the triplet information, and returns a confirmation message to the AF.

There are two implementation manners of steps 810a to 814a, which are as follows:

810a, the V-SMF sends a fourth message to the second SMF:

in step 805a, when the V-SMF receives the third message, the V-SMF may determine the downlink data notification status event according to the SMF subscription association identifier in the third message, and determine that the subscription of the event needs to be updated according to the message. In this embodiment of the present application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

The message carries triple information, transaction identification and downlink data transmission state indication information. The downlink data transmission status indication information is also referred to as event subscription type indication information, and is generated in the event subscription process and used for indicating the first event.

811a, the second SMF sends an eighth message to the PCF:

The message carries triple information, a PCC rule identifier and downlink data transmission state indication information received in the event subscription process.

812a, PCF updates PCC rule with triple information, and sends a fifth policy rule to the second SMF:

the PCF updates the PCC rule based on the triplet information, i.e. the triplet information is included in the filter template in the PCC rule. Optionally, the PCC rule may include downlink data transmission status notification control indication information. The downlink data transmission state notification control indication information is generated in the process of event subscription, and the PCF can determine the indication information through the corresponding relation between the indication information and the PCC rule identifier; the downlink data transmission status notification control indication information may be generated by the PCF according to the downlink data transmission status indication information, and is not limited herein.

Optionally, the downlink data transmission state notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

813a, the second SMF updates the first N4 information (N4 information), and sends the fourth policy rule to the V-SMF:

and the second SMF updates the first N4 information carrying the first PDR according to the PCC rule. The first N4 information further includes downlink data transmission status notification control indication information, and the first PDR is determined according to the PCC rule, and carries the same priority information and filter template as the PCC rule.

And the second SMF returns an acknowledgement message to the V-SMF, wherein the message carries the first N4 information. Optionally, the downlink data transmission state notification control indication information may also be carried in the acknowledgement message, which is not limited herein.

814a, the V-SMF sends the UPF a second N4 message:

since the first N4 information or the acknowledgement message in step 813a includes the downlink data transmission state notification control indication information, the V-SMF determines that the first N4 information is used to detect the downlink data transmission state event. The V-SMF determines second N4 information from the first N4 information.

when the V-SMF receives a UE unreachable notification of the AMF, the V-SMF may determine a second PDR from the first PDR. The second PDR is generated from the first PDR, and includes the same filter template and priority information as the first PDR. The V-SMF can determine the associated FAR according to the downlink data transmission state notification control indication information and the second PDR. The FAR is used to instruct the UPF to drop and report packets matching the second PDR.

When the V-SMF receives notification that the UE of the AMF is in an idle state, the V-SMF may determine a second PDR from the first PDR, the second PDR being generated from the first PDR and including the same filter template and priority information as the first PDR. The V-SMF can determine the associated FAR and URR according to the downlink data transmission state notification control indication information and the second PDR. The FAR is used to instruct the UPF to discard the cached data matching the second PDR, and the URR is used to instruct the UPF to report when the cached data packet matching the second PDR is discarded.

B: the message does not carry an indication identifier of event subscription, and a corresponding policy rule is generated according to the event subscription, and the specific implementation mode is as follows:

810a, the V-SMF determines that it needs to request updating of policy rules for processing data, and sends a fourth message to the second SMF:

in step 805a, when the V-SMF receives the third message, the V-SMF may determine the downlink data delivery status event according to the SMF subscription association identifier in the third message, and determine that the subscription of the event needs to be updated according to the message. In this embodiment of the present application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

And the V-SMF sends an Nsmf _ PDSnessonUpdate Request message to the second SMF, wherein the message is used for requesting to Update the first N4 information. In this embodiment, this message may also be referred to as a fourth message. The triple information and the transaction identifier are carried in the message. The transaction identifier is generated when an event is subscribed, and is used to represent an event between the first SMF and the second SMF, specifically, in this embodiment, corresponds to a subscription of a downlink data delivery status event.

811a, the second SMF sends an eighth message to the PCF:

The message carries the triple information and the PCC rule identification.

In step 812a, the PCC rule received by the second SMF includes a PCC rule identifier, and since the second SMF stores the correspondence between the PCC rule identifier and the transaction identifier during subscription, the second SMF may determine the transaction identifier corresponding to the PCC rule according to the PCC rule identifier.

814a, the V-SMF sends the UPF a second N4 message:

the V-SMF may determine that the first N4 information is used to detect a downstream data notification status event by associating the first N4 information with a subscription for the downstream data notification status event based on the transaction identification received in step 813 a. The V-SMF determines second N4 information based on the first N4 information and the subscription of the downstream data notification status event.

815a-817a：

Steps 815a to 817a are similar to steps 615 to 617 of the embodiment shown in FIG. 6, and are not repeated herein.

Referring to fig. 8b, based on the subscription of fig. 7 to the downlink data transmission status event, in this embodiment, a process of obtaining a corresponding policy rule when updating the event is provided, and for a scenario in which the PDU session has an I-SMF, the V-SMF may be replaced by the I-SMF, which is not limited herein specifically, and the process includes:

801b, UE accesses to the network, establishes PDU session:

at this point the AF has completed subscription to the downstream data transmission state event according to the embodiment shown in fig. 7.

802b-809b:

Steps 802b to 809b are similar to steps 802a to 809a of the example of fig. 8a, and are not described again here.

In the embodiment of the present application, step 807b may also be performed before step 805b or step 806b, as long as it is performed after step 804 b; step 808b may also be performed before any of steps 804b to 807b, as long as it is performed after step 803 b; step 809b may also be performed before any of steps 803b to 808b, as long as it is performed after step 802b, and is not limited herein.

There are two implementation ways for steps 810b to 813b, which are as follows:

810b, the second SMF determines that it needs to request updating of the policy rules for processing data, and sends an update request message to the PCF:

in step 804b or 806b, the message received by the second SMF carries an SMF subscription association identifier, and the second SMF may determine a downlink data transfer state event according to the identifier, and determine that the subscription of the event needs to be updated according to the message. In this embodiment of the present application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

In the event subscription process, the second SMF stores the correspondence between the SMF subscription association identifier and the PCC rule identifier, and at this time, the second SMF may determine the corresponding PCC rule identifier according to the SMF subscription association identifier.

In the embodiment of the present application, the step 810b may also be performed before any one of the steps 805b to 809b, as long as the step is performed after the step 804b or 806b, which is not limited herein.

If step 810b is performed after step 806b, step 806b the second SMF may determine that the V-SMF completed the update of the event, at which point it is more conservative to request an update from the PCF.

811b, PCF updates PCC rule with triple information, and sends a fifth policy rule to the second SMF:

the implementation of step 811b is similar to the implementation of step 812a in the example of fig. 8a, and is not described here again.

812b, the second SMF updates the first N4 information (N4 information), and sends a fourth policy rule to the V-SMF:

In step 812a, the PCC rule received by the second SMF includes a PCC rule identifier, and since the second SMF stores the corresponding relationship between the PCC rule identifier and the SMF subscription association identifier during subscription, the second SMF may determine, according to the PCC rule identifier, an SMF subscription association identifier corresponding to the PCC rule.

And the second SMF returns a confirmation message to the V-SMF, wherein the message carries the first N4 information and the SMF subscription association identifier. In the embodiment of the present application, the first N4 information generated in the event updating process may also be referred to as a fourth policy rule.

811b-813b：

The implementation manner of step 811b to step 813b is similar to that of step 812a to step 814a implemented in fig. 8a, and is not described herein again.

The message carries the triple information and the PCC rule identification.

811b-813b：

The implementation of step 811B to step 813B is similar to the implementation of step 812a to step 814a in the example of fig. 8a, and is not described here again.

814b-816b：

Steps 814b through 816b are similar to steps 714 through 716 of the embodiment shown in FIG. 7, and are not repeated here.

3. Deleting downlink data transmission state events:

referring to fig. 9a, based on the subscription of fig. 6 to the downlink data transmission state event, in the embodiment, a flow of deleting the event subscription when the event is deleted is provided, and for a scenario in which a PDU session has an I-SMF, the V-SMF may be replaced by the I-SMF, which is not limited herein specifically, and the flow includes:

901a, UE accesses to network, establishes PDU session:

this is consistent with step 801a in the example of fig. 8a, and is not described here again.

902a, AF sends a unsubscribe request message to NEF:

the AF sends an Nnef _ EventExposure _ unpubscribe Request message to the NEF requesting deletion of the event subscription.

903a, NEF sends unsubscribe request message to UDM:

the NEF sends a nutm _ EventExposure _ unpubscribe Request message to the UDM requesting deletion of the event subscription.

904a, the UDM sends a unsubscribe request message to the second SMF with which the UE is registered:

the UDM sends an Nsmf _ evendexposure _ unpubscribe Request message to a second SMF with which the UE is registered, requesting deletion of the event subscription.

905a, the second SMF sends a unsubscribe request message to the V-SMF:

the second SMF sends an Nsmf _ EventExposure _ Unscubscribe Request message to the V-SMF registered by the UE, requesting deletion of the event subscription.

906a, V-SMF returns an acknowledgement message to the second SMF.

907a, the second SMF returns an acknowledgement message to the UDM.

908a, UDM returns an acknowledgement message to NEF:

909a, NEF returns an acknowledgement message to AF.

910a, the V-SMF determines that it needs to request deletion of the first N4 message and sends a sixth message to the second SMF:

the V-SMF may determine that the downstream data delivery state event is required to be deleted according to the SMF subscription association identifier in the unsubscribe request in step 905a, and determine that the subscription of the event is required to be deleted according to the request, thereby determining that the deletion of the first N4 information is required to be requested. In this embodiment of the present application, the SMF subscription association identifier may also be referred to as a third identifier, and is used to identify the subscription of the first event.

911a-914a：

Steps 911 to 914 are similar to steps 511 to 514 in the embodiment shown in fig. 5, and are not described again here.

Referring to fig. 9b, based on the subscription of fig. 7 to the downlink data transmission state event, in the embodiment, a flow of deleting the event subscription when the event is deleted is provided, and for a scenario in which a PDU session has an I-SMF, the V-SMF may be replaced by the I-SMF, which is not limited herein specifically, and the flow includes:

901b, UE accesses to the network, and establishes PDU conversation:

902b-909b:

Steps 902b through 909b are similar to steps 902a through 909a of the example of fig. 9a, and are not described again here.

910b, the second SMF sends an update request message to the PCF:

and the second SMF sends an Nsmf _ PDUSESSion _ Update Request message to the PCF to Request to delete the downlink data notification failure event.

The message carries an SMF subscription association identifier and a unsubscribe indication, wherein the SMF subscription association identifier is generated by a second SMF when the event is subscribed.

911b-913b：

Steps 911b through 913b are similar to steps 513b through 515b of the example of fig. 5a, and are not repeated here.

Referring to fig. 10, a session management network element in an embodiment of the present application is described below, where in the embodiment of the present application, a structure of the session management network element includes:

a first receiving unit 1001, configured to receive a first message, where the first message is used to request to create a subscription for a first event, where the subscription for the first event is an event subscription for a user equipment UE, and the first message includes first description information of data, where the data is data received by the UE;

a first sending unit 1002, configured to send a second message to a second session management network element SMF according to a request policy indication information, where the second message includes the first description information, and the second message is used to request a first policy rule corresponding to the first description information;

a second receiving unit 1003, configured to receive the first policy rule sent by the second SMF;

a first determining unit 1004, configured to determine a second policy rule according to the first policy rule;

a second sending unit 1005, configured to send the second policy rule to a user plane function network element UPF, so that the UPF processes the data.

Referring to fig. 11, in the embodiment of the present application, another structure of the session management network element includes:

a first receiving unit 1101, configured to receive a first message, where the first message is used to request to create a subscription for a first event, where the subscription for the first event is an event subscription for a user equipment UE, and the first message includes first description information of data, where the data is data received by the UE;

a first sending unit 1102, configured to send a second message to a second session management network element SMF according to a request policy indication information, where the second message includes the first description information, and the second message is used to request a first policy rule corresponding to the first description information;

a second receiving unit 1103, configured to receive the first policy rule sent by the second SMF;

a first determining unit 1104, configured to determine a second policy rule according to the first policy rule;

a second sending unit 1105, configured to send the second policy rule to a user plane function network element UPF, so that the UPF processes the data.

A third receiving unit 1106, configured to receive a third message, where the third message is used to request to update the subscription of the first event, and the third message includes second description information of the data;

a third sending unit 1107, configured to send a fourth message to the second SMF, where the fourth message is used to request to update the first policy rule, and the fourth message includes the first identifier and the second description information;

a fourth receiving unit 1108, configured to receive a fourth policy rule sent by the second SMF, where the fourth policy rule is a policy rule obtained after the first policy rule is updated;

a first updating unit 1109, configured to update the second policy rule according to the fourth policy rule.

A fifth receiving unit 1110, configured to receive a fifth message, where the fifth message is used to request to delete the subscription of the first event;

a fourth sending unit 1111, configured to send a sixth message to the second SMF, where the sixth message is used to request to delete the first policy rule, and the sixth message includes the first identifier and a deletion indication.

A sixth receiving unit 1112, configured to receive the request policy indication information sent by the second SMF.

In this embodiment, the second receiving unit 1103 may include a first receiving sub-unit 11031;

a first receiving subunit 11031, configured to receive the first policy rule and notification control indication information sent by the second SMF, where the notification control indication information is determined according to the event subscription type indication information;

in this embodiment, the first determination unit 1104 may include a first determination subunit 11041 or a second determination subunit 11042;

a first determining subunit 11041, configured to determine the second policy rule according to the first policy rule and the notification control indication information.

A second determining subunit 11042, configured to determine the second policy rule according to the first policy rule and the subscription of the first event.

Referring to fig. 12, a session management network element in an embodiment of the present application is described below, where in the embodiment of the present application, a structure of the session management network element includes:

a seventh receiving unit 1201, configured to receive a second message sent by a first session management network element SMF, where the second message includes first description information and event subscription type indication information, the event subscription type indication information is used to indicate a type of an event subscription, the event subscription is an event subscription for a user equipment UE, and the first description information is used to identify data received by the UE;

a fifth sending unit 1202, configured to send a seventh message to a policy control network element PCF, where the seventh message is used to request a third policy rule corresponding to the first description information, and the seventh message includes the first description information and the event subscription type indication information;

an eighth receiving unit 1203, configured to receive the third policy rule sent by the PCF;

a second determining unit 1204, configured to determine a first policy rule according to the third policy rule;

a sixth sending unit 1205 is configured to send the first policy rule to the first SMF.

Referring to fig. 13, in the embodiment of the present application, another structure of the session management network element includes:

a seventh receiving unit 1301, configured to receive a second message sent by a first session management network element SMF, where the second message includes first description information and event subscription type indication information, the event subscription type indication information is used to indicate a type of an event subscription, the event subscription is an event subscription for a user equipment UE, and the first description information is used to identify data received by the UE;

a fifth sending unit 1302, configured to send a seventh message to a policy control network element PCF, where the seventh message is used to request a third policy rule corresponding to the first description information, where the seventh message includes the first description information and a downlink data notification event subscription trigger, and the downlink data notification event subscription trigger is determined according to the event subscription type indication information;

an eighth receiving unit 1303, configured to receive the third policy rule sent by the PCF;

a second determining unit 1304, configured to determine the first policy rule according to the third policy rule;

a sixth sending unit 1305, configured to send the first policy rule to the first SMF.

A ninth receiving unit 1306, configured to receive first request policy indication information sent by the PCF, where the first request policy indication information includes indication information reporting that a downlink data notification event subscription is received;

a seventh sending unit 1307, configured to send second request policy indication information to the first SMF, where the second request policy indication information includes at least one of indication information that policy and charging control is applied to the UE, indication information that a downlink data notification event subscription is reported to be received, or indication information that data description information is reported to be received.

A tenth receiving unit 1308, configured to receive a fourth message sent by the first SMF, where the fourth message includes the first identifier and the second description information of the data;

an eighth sending unit 1309, configured to send an eighth message to the PCF, where the eighth message includes a second identifier and the second description information, the eighth message is used to request to update the third policy rule, and the second identifier is identifier information of the third policy rule, and is determined according to the first identifier;

an eleventh receiving unit 1310, configured to receive a fifth policy rule sent by the PCF, where the fifth policy rule is a policy rule obtained after updating the third policy rule;

a second updating unit 1311, configured to update the first policy rule according to the fifth policy rule, so as to obtain a fourth policy rule;

a ninth sending unit 1312, configured to send the fourth policy rule to the first SMF.

A twelfth receiving unit 1313, configured to receive a sixth message sent by the first SMF, where the sixth message includes the first identifier and a deletion instruction;

a tenth sending unit 1314, configured to send a ninth message to the PCF, where the ninth message is used to request to delete the third policy rule, and the ninth message includes the second identifier, where the second identifier is identification information of the third policy rule, and the second identifier is determined according to the first identifier.

In this embodiment, the eighth receiving unit 1303 may include a second receiving sub-unit 13031;

a second receiving subunit 13031, configured to receive the third policy rule and notification control indication information sent by the PCF, where the notification control indication information is determined according to the downlink data notification event subscription trigger;

in this embodiment, the sixth transmitting unit 1305 may include a first transmitting sub-unit 13051;

a first sending subunit 13051, configured to send the first policy rule and the notification control indication information to the first SMF.

Fig. 14 is a schematic structural diagram of a session management network element according to an embodiment of the present application, where the session management network element 1400 may include one or more Central Processing Units (CPUs) 1401 and a memory 1405, where the memory 1405 stores one or more applications or data.

Memory 1405 may be volatile storage or persistent storage, among others. The program stored in memory 1405 may include one or more modules, each of which may include a sequence of instructions operating on a service control unit. Further, central processor 1401 may be configured to communicate with memory 1405, and execute a series of instruction operations in memory 1405 on business control unit 1400.

The traffic control unit 1400 may also include one or more power supplies 1402, one or more wired or wireless network interfaces 1403, one or more input-output interfaces 1404, and/or one or more operating systems, such as Windows Server, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

The service control unit 1400 may perform operations performed by the session management network element in the embodiments shown in fig. 2 to fig. 9b, which are not described herein again.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions in the present application may be wholly or partially embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and the like.

Claims

1. A method for providing policy rules, the method being applied to a first session management network element, SMF, the method comprising:

receiving the first policy rule sent by the second SMF;

determining a second policy rule according to the first policy rule;

2. The method of claim 1, wherein the second message further comprises a first identifier, wherein the first identifier is used to identify a transaction between the first SMF and the second SMF, and wherein after the first message is sent to a second session management network element, SMF, the method further comprises:

receiving a third message, wherein the third message is used for requesting to update the subscription of the first event and comprises second description information of the data;

sending a fourth message to the second SMF, where the fourth message is used to request updating of the first policy rule, and the fourth message includes the first identifier and the second description information;

receiving a fourth policy rule sent by the second SMF, where the fourth policy rule is obtained by updating the first policy rule according to the second description information;

updating the second policy rule according to the fourth policy rule.

3. The method of claim 1, further comprising a first identifier in the second message, the first identifier being used to identify a transaction between the first SMF and the second SMF, and after sending the first message to a second session management network element, SMF, the method further comprising:

receiving a fifth message, the fifth message being used to request deletion of the subscription of the first event;

sending a sixth message to the second SMF, the sixth message being used for requesting deletion of the first policy rule, the sixth message including the first identity and a deletion indication.

4. The method according to any of claims 1 to 3, wherein before sending the second message to the second session management network element, SMF, according to the request policy indication information, the method further comprises:

and receiving the request policy indication information sent by the second SMF.

5. The method according to any one of claims 1 to 3, characterized in that:

the request policy indication information includes at least one of indication information that policy charging control is applied to the UE, indication information that a downlink data notification event subscription is reported to be received, or indication information that received data description information is reported to be received.

6. The method according to any one of claims 1 to 3, characterized in that:

the second message further includes event subscription type indication information, where the event subscription type indication information is used to indicate a type of subscription of the first event.

7. The method of any of claims 1-3, wherein the receiving the first policy rule for the second SMF transmission comprises:

receiving the first policy rule and notification control indication information sent by the second SMF, where the notification control indication information is determined according to the event subscription type indication information;

the determining a second policy rule according to the first policy rule comprises:

and determining the second policy rule according to the first policy rule and the notification control indication information.

8. The method of any of claims 1-3, wherein determining a second policy rule based on the first policy rule comprises:

determining the second policy rule according to the first policy rule and the subscription of the first event.

9. A method for providing policy rules, the method being applied to a second session management network element, SMF, and the method comprising:

receiving a second message sent by a first session management network element (SMF), wherein the second message comprises first description information and event subscription type indication information, the event subscription type indication information is used for indicating the type of event subscription, the event subscription is the event subscription for User Equipment (UE), and the first description information is used for identifying data received by the UE;

receiving the third policy rule sent by the PCF;

determining a first policy rule according to the third policy rule;

sending the first policy rule to the first SMF.

10. The method according to claim 9, wherein before said receiving the second message sent by the first session management network element SMF, the method further comprises:

receiving first request policy indication information sent by the PCF, wherein the first request policy indication information comprises indication information reporting that a downlink data notification event subscription is received;

and sending second request policy indication information to the first SMF, wherein the second request policy indication information comprises at least one of indication information of applying policy charging control to the UE, indication information of reporting received downlink data notification event subscription or indication information of reporting received data description information.

11. The method of claim 9 or 10, wherein if the receiving the third policy rule sent by the PCF comprises:

receiving the third policy rule and notification control indication information sent by the PCF, the notification control indication information being determined according to the downlink data notification event subscription trigger;

the sending the first policy rule to the first SMF comprises:

and sending the first policy rule and the notification control indication information to the first SMF.

12. The method of claim 9 or 10, wherein the second message includes a first identifier identifying a transaction between the second SMF and the first SMF, and wherein after sending the seventh message to the PCF, the method further comprises:

receiving a fourth message sent by the first SMF, wherein the fourth message comprises the first identification and second description information of the data;

sending an eighth message to the PCF, where the eighth message includes a second identifier and the second description information, the eighth message is used to request to update the third policy rule, the second identifier is identifier information of the third policy rule, and the second identifier is determined according to the first identifier;

receiving a fifth policy rule sent by the PCF, wherein the fifth policy rule is obtained by updating the third policy rule according to the second description information;

updating the first policy rule according to the fifth policy rule to obtain a fourth policy rule;

sending the fourth policy rule to the first SMF.

13. The method of claim 9 or 10, wherein the second message includes a first identifier identifying a transaction between the second SMF and the first SMF, and wherein after sending the seventh message to the PCF, the method further comprises:

receiving a sixth message sent by the first SMF, wherein the sixth message comprises the first identifier and a deletion instruction;

and sending a ninth message to the PCF, wherein the ninth message is used for requesting deletion of the third policy rule, the ninth message includes the second identifier, the second identifier is identification information of the third policy rule, and the second identifier is determined according to the first identifier.

14. A session management network element, SMF, the SMF comprising:

15. The SMF of claim 14, further comprising a first identifier in the second message, the first identifier identifying a transaction between the first SMF and the second SMF, the SMF further comprising:

a third receiving unit, configured to receive a third message, where the third message is used to request to update the subscription of the first event, and the third message includes second description information of the data;

a third sending unit, configured to send a fourth message to the second SMF, where the fourth message is used to request to update the first policy rule, and the fourth message includes the first identifier and the second description information;

a fourth receiving unit, configured to receive a fourth policy rule sent by the second SMF, where the fourth policy rule is a policy rule obtained after the first policy rule is updated according to the second description information;

and the first updating unit is used for updating the second strategy rule according to the fourth strategy rule.

16. The SMF of claim 14, further comprising a first identifier in the second message, the first identifier identifying a transaction between the first SMF and the second SMF, the SMF further comprising:

a fifth receiving unit, configured to receive a fifth message, where the fifth message is used to request to delete the subscription of the first event;

a fourth sending unit, configured to send a sixth message to the second SMF, where the sixth message is used to request to delete the first policy rule, and the sixth message includes the first identifier and a deletion instruction.

17. The SMF according to any of claims 14 to 16, further comprising:

a sixth receiving unit, configured to receive the request policy indication information sent by the second SMF.

18. The SMF according to any of claims 14 to 16, wherein:

19. The SMF according to any of claims 14 to 16, wherein:

20. The SMF according to any of claims 14 to 16, wherein the second receiving unit comprises:

a first receiving subunit, configured to receive the first policy rule and notification control indication information sent by the second SMF, where the notification control indication information is determined according to the event subscription type indication information;

the first determination unit includes:

a first determining subunit, configured to determine the second policy rule according to the first policy rule and the notification control indication information.

21. The SMF according to any of claims 14 to 16, wherein the first determining unit comprises:

a second determining subunit, configured to determine the second policy rule according to the first policy rule and the subscription of the first event.

22. A session management network element, SMF, the SMF comprising:

a seventh receiving unit, configured to receive a second message sent by a first session management network element SMF, where the second message includes first description information and event subscription type indication information, the event subscription type indication information is used to indicate a type of an event subscription, the event subscription is an event subscription for a user equipment UE, and the first description information is used to identify data received by the UE;

23. The SMF of claim 22, wherein said SMF further comprises:

a ninth receiving unit, configured to receive first request policy indication information sent by the PCF, where the first request policy indication information includes indication information reporting that a downlink data notification event subscription is received;

a seventh sending unit, configured to send second request policy indication information to the first SMF, where the second request policy indication information includes at least one of indication information that policy and charging control is applied to the UE, indication information that a downlink data notification event subscription is reported to be received, or indication information that data description information is reported to be received.

24. The SMF according to claim 22 or 23, wherein if said eighth receiving unit comprises:

a second receiving subunit, configured to receive the third policy rule and notification control indication information sent by the PCF, where the notification control indication information is determined according to the downlink data notification event subscription trigger;

the sixth transmitting unit includes:

a first sending subunit, configured to send the first policy rule and the notification control indication information to the first SMF.

25. The SMF according to claim 22 or 23, wherein the second message comprises a first identity identifying a transaction between the second SMF and the first SMF, the SMF further comprising:

a tenth receiving unit, configured to receive a fourth message sent by the first SMF, where the fourth message includes the first identifier and the second description information of the data;

an eighth sending unit, configured to send an eighth message to the PCF, where the eighth message includes a second identifier and the second description information, the eighth message is used to request to update the third policy rule, the second identifier is identifier information of the third policy rule, and the second identifier is determined according to the first identifier;

an eleventh receiving unit, configured to receive a fifth policy rule sent by the PCF, where the fifth policy rule is a policy rule obtained after updating the third policy rule according to the second description information;

the second updating unit is used for updating the first strategy rule according to the fifth strategy rule to obtain a fourth strategy rule;

a ninth sending unit, configured to send the fourth policy rule to the first SMF.

26. The SMF according to claim 22 or 23, wherein the second message comprises a first identity identifying a transaction between the second SMF and the first SMF, the SMF further comprising:

a twelfth receiving unit, configured to receive a sixth message sent by the first SMF, where the sixth message includes the first identifier and a deletion instruction;

a tenth sending unit, configured to send a ninth message to the PCF, where the ninth message is used to request to delete the third policy rule, and the ninth message includes the second identifier, where the second identifier is identifier information of the third policy rule, and the second identifier is determined according to the first identifier.

27. A session management network element, SMF, comprising:

a processor, a memory, an input-output device, and a bus;

the processor is configured to perform the method of any one of claims 1 to 8.

28. A session management network element, SMF, comprising:

a processor, a memory, an input-output device, and a bus;

the processor is configured to perform the method of any one of claims 9 to 13.

29. A computer-readable storage medium, characterized in that a program is stored in the computer-readable storage medium, which, when executed by the computer, performs the method according to any one of claims 1 to 13.

30. A computer program product, characterized in that when the computer program product is executed on a computer, the computer performs the method according to any of claims 1 to 13.