RU2786671C2 - Communication method and device - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: object of a session management function is determined based on at least one of a name of a data transmission network, segment information, and an identifier of an application function service. The first message is transmitted to the object of the session management function, where the first message is used for subscription for an event of a terminal device. The first message includes service description information, and service description information is used for indication of a service corresponding to the event of the terminal device. According to technical solutions in the present disclosure, subscription for the event of the terminal device is performed by the object of the session management function, which controls a specific service. When receiving a notification about detection of the service from an object of a user plane function, the object of the session management function prescribes an object of an access and mobility management function to track the event of the terminal device.

EFFECT: provision of signing of an event of a terminal device and tracking for a specific service in 5G architecture.

38 cl, 52 dwg

Description

The field of technology to which the invention belongs

The present invention relates to the field of communication technologies and, in particular, to a communication method and device.

State of the art

Fig. 1 is a diagram of a non-roaming architecture of an existing evolved packet system (EPS). To support a service capability server/application server (SCS/AS) having a third-party application (eg, machine-type application) installed in the EPS network, it is necessary to improve the existing network architecture. A service capability exposure function (SCEF) network element is introduced. Fig. 2 is an interface architecture diagram in a 3rd generation partnership project ( ^3GPP ). The EPS network architecture is implemented using SCEF, where SCEF provides the SCS/AS with the service and capabilities provided by the secure 3GPP network interface.

The machine type service includes a service that has a low delay requirement, that is, a service with a high delay requirement. Based on the aforementioned capability exposure architecture to support high latency service communication, a monitoring event "availability after DDN failure" of a terminal device after a downlink data notification (DDN) failure is defined. In other words, the SCS/AS can subscribe to the DDN availability monitoring event from the 3GPP EPS network using SCEF. When the SCS/AS sends a data packet to an end device in the EPS network, if the end device is in an unreachable state, the EPS network will trigger a DDN failover event, that is, monitor the state of the end device. When the terminal device transitions to the available state, the network reports the available state of the terminal device to the SCS/AS using SCEF, so that the SCS/AS retransmits the data to the terminal device.

In the current solution, both session and mobility are controlled by a mobility management entity (MME). When receiving a DDN message sent by the serving gateway (SGW) and when the end device is in an unavailable state, for example, the MME initiates a paging call for the end device, but does not receive a response, the end device is in power saving mode (PSM ), or the end device is in mobile initiated connection only (MICO) mode, then the MME directly triggers the monitoring event. However, in the 5 ^th generation (5G) mobile communication system architecture, session management, access and mobility management are separately controlled by different function objects. In this architecture, how the network configures the appropriate endpoint event and fires the reported event is a technical challenge that is currently unresolved.

Disclosure of the essence of the invention

The present invention provides a communication method and apparatus for subscribing to an event of a tag in the 5G architecture.

According to a first aspect, a communication method is provided, which includes: determining a session management function object based on at least one of a data network name, segment information, and an application function service identifier; and transmitting the first message to the session control function object, where the first message is used to subscribe to the tag event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the tag event.

In this aspect, a tag event is subscribed from a session management function object that manages a particular service, and a session management function object manages the network configuration after the tag event. Thus, a terminal event can be subscribed and tracked for a specific service in the 5G architecture.

With reference to the first aspect, in the first possible implementation, the service description information is further used to determine an application function object that provides a service to a terminal device.

In this implementation, one or more application function objects may provide a service to a terminal device. When subscribing to a tag event, the service description information is used to indicate the service corresponding to the tag event, so that the application function objects that subscribe to the tag event may differ from each other.

With reference to the first aspect or the first possible implementation of the first aspect, in the second possible implementation, the first message further includes an event correlation identifier and tag event type information, the event correlation identifier is used to identify a correlation relationship between the tag event and the function object, which subscribes to a tag event, and the event type information is used to identify the tag event.

In this implementation, when a terminal event is subscribed from the session management function object, the event's correlation identifier and event type information are passed. The function object that subscribes to the tag event can be identified based on the event correlation ID, and the tag event type can be identified based on the event type information.

With reference to the first aspect or the first possible implementation of the first aspect, in the third possible implementation, the method further includes: sending a second message to an access and mobility control function object, where the second message is used to subscribe to a tag event, the second message includes an identifier event correlation and tag event type information, the event correlation ID is used to identify the correlation relationship between the tag event and the function object that subscribes to the tag event, and the event type information is used to identify the tag event.

In this implementation, when a terminal event is subscribed from an access and mobility control function object, an event correlation identifier and event type information are transmitted. The function object that subscribes to the tag event can be identified based on the event correlation ID, and the tag event type can be identified based on the event type information.

With reference to the first aspect, the first possible implementation of the first aspect, the second possible implementation of the first aspect, or the third possible implementation of the first aspect, in the fourth possible implementation, the method further includes: receiving a third message from an application function object, where the third message is used to subscribe to an event terminal, and the third message includes service description information.

In this implementation, the application function object can subscribe to a terminal event from the control function object; when subscribing to a tag event, the application function object indicates, using the service description information, a service corresponding to the tag event to distinguish a third-party application that subscribes to the tag event. The management function object may be a network exposure function object, a unified data management function object, or a policy management function object.

With reference to the fourth possible implementation of the first aspect, in the fifth possible implementation, the third message further includes at least one of: a tag identifier corresponding to the tag event, tag event type information, a communication network name, segment information, and an identifier application function services.

With reference to the fourth possible implementation of the first aspect or the fifth possible implementation of the first aspect, in the sixth possible implementation, receiving a third message from the application function object includes: receiving a third message forwarded by the network exposure function object.

With reference to the fourth possible implementation of the first aspect, the fifth possible implementation of the first aspect, or the sixth possible implementation of the first aspect, in the seventh possible implementation, the method further includes: transmitting at least one of service description information, event correlation ID, tag ID, type terminal event, data network name, segment information, and application function service ID into the unified data repository function object for storage.

In this implementation, the unified data repository function object can store all information related to the subscribed endpoint event.

With reference to the first aspect, the first possible implementation of the first aspect, the second possible implementation of the first aspect, the third possible implementation of the first aspect, the fourth possible implementation of the first aspect, the fifth possible implementation of the first aspect, the sixth possible implementation of the first aspect, or the seventh possible implementation of the first aspect, in the eighth of an exemplary implementation, the method further includes: obtaining at least one of service description information, an event correlation identifier, a terminal identifier, terminal event type information, a data network name, segment information, and an application function service identifier locally or from a function object. unified data repository.

With reference to the fourth possible implementation of the first aspect, the fifth possible implementation of the first aspect, the sixth possible implementation of the first aspect, the seventh possible implementation of the first aspect, or the eighth possible implementation of the first aspect, in the aspect of the ninth possible implementation, the method further includes: receiving an event notification of the terminal device from an access and mobility control function object or a session management function object; and passing the tag event notification to the application function object.

In this implementation, when a tag event is detected, the access and mobility control function object or the session management function object notifies the network exposure function object, and then the network exposure function object notifies the application function object that the tag event is detected.

With reference to the first aspect, the first possible implementation of the first aspect, the second possible implementation of the first aspect, the third possible implementation of the first aspect, the fourth possible implementation of the first aspect, the fifth possible implementation of the first aspect, the sixth possible implementation of the first aspect, the seventh possible implementation of the first aspect, the eighth possible implementation of the first aspect, or the ninth possible implementation of the first aspect, in the tenth possible implementation, the tag event type includes a tag availability event after downlink data notification failure.

Accordingly, according to the second aspect, a communication device is provided. The communication device has a function of realizing the behavior of the communication device in the above method. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function.

In an exemplary implementation, the communication device includes: a processing unit configured to determine a session management function object based on at least one of a data network name, segment information, and an application function service identifier; and a transmission unit configured to transmit the first message to the session control function object, where the first message is used to subscribe to the tag event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the tag event.

In another possible implementation, the communications device includes a processor, the processor being configured to connect to, read, and execute instructions in the memory to implement the above method.

Based on the same concept of the invention, the principles and benefits of the device for solving technical problems refer to the above possible implementations of the communication device method and the benefits obtained. Therefore, to implement the device, refer to the implementation of the method. Repetitive parts are again not described.

According to a third aspect, a communication method is provided, which includes: receiving a first message sent by a session management function object, where the first message is used to subscribe to a tag event; monitoring a subscribed end device event; and when the tag event is detected, passing the tag event notification to a function object that subscribes to the tag event, where the tag event notification includes at least one of: a tag event identifier corresponding to the tag event, and an identifier tag event event correlation identifier, where the event correlation identifier is used to identify the correlation relationship between the tag event and the function object that subscribes to the tag event.

In this aspect, the access and mobility control function object may receive a tag event subscription from the session management function object and pass, when a tag event is detected, a tag event notification to a function object that subscribes to the tag event. Thus, in the 5G architecture, it is possible to subscribe to an end device event and track it.

Accordingly, according to the fourth aspect, a communication device is provided. The communication device has a function of realizing the behavior of the communication device in the above method. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function.

In an exemplary implementation, the communication device includes: a receiving unit configured to receive a first message sent by a session control function object, where the first message is used to subscribe to an event of the terminal device; a monitoring unit configured to monitor the subscribed event of the terminal device; and a sender configured to: when the monitor detects a tag event, send a tag event notification to a function object that subscribes to the tag event, where the tag event notification includes at least one of: a tag event device corresponding to the tag event, and a tag event event correlation ID, where the event correlation ID is used to identify a correlation relationship between the tag event and the function object that subscribes to the tag event.

In another possible implementation, the communication device includes a processor, the processor being configured to connect to, read, and execute instructions in the memory to implement the above method.

Based on the same concept of the invention, the principles and benefits of the device for solving the technical problem refer to the above possible implementations of the communication device method and the benefits obtained. Therefore, to implement the device, refer to the implementation of the method. Repetitive parts are again not described.

According to a fifth aspect, a communication method is provided, which includes: receiving a notification that is for monitoring a terminal device availability event and that is transmitted by a session management function object or a management function object; monitoring of end device availability event; and transmitting a tag availability notification to a session management function object or a management function object upon detecting a tag availability event, where the tag availability notification is used to track the tag availability event after downlink data notification failure.

In this aspect, the session management function object may monitor the terminal's availability event after a downlink data notification failure. When tag reachability is detected, the access and mobility control function object notifies the session management function object to activate the session management function object to monitor the tag availability event after downlink data notification failure. Thus, in the 5G architecture, it is possible to subscribe to an end device event and track it.

Accordingly, according to the sixth aspect, a communication device is provided. The communication device has a function of realizing the behavior of the communication device in the above method. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function.

In an exemplary implementation, the communications device includes: a receiving unit configured to receive a notification that is for monitoring a terminal device's availability event and that is transmitted by a session control function object; a monitoring unit configured to monitor the availability event of the terminal device; and a transmission unit configured to send a tag availability notification to a session management function object when the monitoring unit detects a tag availability event, where the tag availability notification is used to monitor the tag availability event after downlink data notification failure.

In another possible implementation, the communication device includes a processor, wherein the processor is configured to connect to, read, and execute an instruction in the memory to implement the above method.

Based on the same inventive concept, the principles and benefits of the device for solving the technical problem refer to the above possible implementations of the communication device method and the benefits obtained. Therefore, to implement the device, refer to the implementation of the method. Repetitive parts are again not described.

According to a seventh aspect, a communication method is provided, which includes: directing a user plane function object to discover a service, where the service is a service corresponding to a subscribed event of a terminal; receiving a service discovery notification sent by a user plane function object, where the service discovery notification is used to indicate the occurrence of service data; and transmitting, in response to the service discovery notification, a notification that is for monitoring the terminal event to the access and mobility control function object or the control function object.

In this aspect, a terminal event is subscribed from a session control function object that manages a particular service; upon receiving the service discovery notification from the user plane function entity, the session management function entity instructs the access and mobility control function entity to track the terminal event. Thus, a terminal event can be subscribed and tracked for a specific service in the 5G architecture.

With reference to the seventh aspect, in a first possible implementation, telling a user plane function object to discover a service includes: telling a user plane function object to discover a service when the user plane function object does not store access network tunnel information or downlink user plane tunnel information for data transmission services; or instructs the user plane function entity to perform service discovery notification when the user plane function entity does not store access network tunnel information or downlink user plane tunnel information for service data transmission.

With reference to the seventh aspect or the first possible implementation of the seventh aspect, in the second possible implementation, the method further includes: receiving a first message transmitted by a control function object, where the first message is used to indicate a service, and the first message includes service description information for the service .

In this implementation, the tag event subscription is received from the control function object; when subscribing to a tag event, the service description information is used to indicate a service corresponding to the tag event in order to distinguish between third-party applications that subscribe to the tag event.

With reference to the second possible implementation of the seventh aspect, in the third possible implementation, the first message is further used to subscribe to the tag event, the first message includes an event correlation ID and event type information for the tag event, the event correlation ID is used to identify the correlation relationship between a tag event and a function object that subscribes to the tag event, and the event type information is used to identify the tag event.

In this implementation, when a terminal event is subscribed from the session management function object, an event correlation identifier and event type information are passed. The function object that subscribes to the tag event can be identified based on the event correlation ID, and the tag event type can be identified based on the event type information.

With reference to the third possible implementation of the seventh aspect, in the fourth possible implementation, the tag event includes a tag availability event after a downlink data notification failure, and the method further includes: receiving a tag availability notification or a tag availability event notification upon failure of the downlink data notification that is transmitted by the access and mobility control function entity; and transmitting the tag availability notification after the downlink data notification failure to the network exposure function entity or to the application function entity.

With reference to the seventh aspect or the first possible implementation of the seventh aspect, in the fifth possible implementation, the method further includes: receiving a first message sent by the local object to the session management function, where the first message is used to indicate a service, and the first message includes service description information .

In this implementation, in the roaming scenario, a subscription to an endpoint event is received from the local object of the session management function; when subscribing to a tag event, a service corresponding to the tag event is indicated by the service description information to distinguish between third-party applications that subscribe to the tag event.

Accordingly, according to the eighth aspect, a communication device is provided. The communication device has a function of realizing the behavior of the communication device in the above method. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function.

In an exemplary implementation, the communication device includes: a transmission unit configured to direct a user plane function object to discover a service, where the service is a service corresponding to a subscribed event of the terminal; and a receiving unit configured to receive a service discovery notification transmitted by the user plane function object, where the service discovery notification is used to indicate the occurrence of service data, the transmitting unit is further configured to transmit, in response to the service discovery notification, a notification that is for terminal event monitoring to the access and mobility control function object.

In another possible implementation, the communication device includes a processor, the processor being capable of connecting to, reading from, and executing an instruction in the memory to implement the above method.

Based on the same concept of the invention, the principles and benefits of the device for solving the technical problem refer to the above possible implementations of the communication device method and the benefits obtained. Therefore, to implement the device, refer to the implementation of the method. Repetitive parts are again not described.

According to a ninth aspect, a communication method is provided, which includes: receiving a first message sent by a session management function object, where the first message is used to indicate to discover a service, and the service is a service corresponding to a subscribed event of the terminal; detecting a service based on the first message; and passing the service discovery notification to the session management function object, where the service discovery notification is used to indicate the occurrence of service data.

In this aspect, when receiving service data, based on the service discovery indication of the session management function object, the service corresponding to the subscribed event of the terminal is detected and the session management function object is notified. Thus, in the 5G architecture, you can subscribe to an end device event and monitor it.

With reference to the ninth aspect, in a first possible implementation, service discovery based on the first message includes: service discovery based on the first message when access network tunnel information for transmitting service data is not stored.

Accordingly, according to the tenth aspect, a communication device is provided. The communication device has a function of realizing the behavior of the communication device in the above method. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function.

In an exemplary implementation, the communication device includes: a receiving unit configured to receive a first message transmitted by a session control function object, where the first message is used to indicate to discover a service, and the service is a service corresponding to the subscribed event of the terminal, a discovery unit configured to the ability to discover the service based on the first message; and a transmission unit configured to send the service discovery notification to the session management function object, where the service discovery notification is used to indicate the occurrence of service data.

In another possible implementation, the communication device includes a processor, the processor being configured to connect to, read, and execute instructions in the memory to implement the above method.

Based on the same concept of the invention, the principles and benefits of the device for solving the technical problem refer to the above possible implementations of the communication device method and the benefits obtained. Therefore, to implement the device, refer to the implementation of the method. Repetitive parts are again not described.

According to an eleventh aspect, a communication method is provided, which includes: directing a user plane function object to discover a service, where the service is a service corresponding to an event of a terminal to which the first application function object subscribes; receiving a service discovery notification sent by the user plane function object, where the service discovery notification is used to indicate that these services have been discovered; when the terminal device is unavailable, tracking the event of the terminal device based on the service discovery notification; and when the tag event is detected, transmitting the tag event notification to the network exposure function object or the first application function object.

In this aspect, the session control function object instructs the user plane function object to discover a particular service; when the terminal is not available, the session control function object monitors the terminal event based on the service discovery notification sent by the user plane function object, and transmits the terminal event notification when the terminal event is detected. Thus, a terminal event for a specific service can be subscribed and notified in the 5G architecture.

With reference to the eleventh aspect, in a first possible implementation, the tag event includes a tag availability event after a downlink data notification failure or a tag availability event.

With reference to the first possible implementation of the eleventh aspect, in the second possible implementation, when a tag event is detected, a tag availability event notification or a tag availability event notification after a downlink data transmission failure is received, which are transmitted by the access and mobility control function entity.

With reference to the eleventh aspect or the first possible implementation of the eleventh aspect or the second possible implementation of the eleventh aspect, in the third possible implementation, the method further includes: prior to receiving a downlink data transmission failure notification transmitted by an access and mobility control or service discovery function entity, determining that the terminal is unreachable if the unreachability notification sent by the access and mobility control function object is received.

In this implementation, the terminal is unreachable if a downlink data failure notification sent by the AMF can be received, or it could be that the SMF receives an unreachable notification from the AMF when another application function entity is transmitting service data.

With reference to the third possible implementation of the eleventh aspect, in the fourth possible implementation, the method further includes: receiving a first message sent by the local object to the session management function, where the first message is used to indicate a service and indicate to subscribe to an event of the terminal, and the first message includes including service description information for the service and an event correlation identifier and event type information for the terminal event, where the event correlation identifier is used to identify a correlation relationship between the terminal event and a function object that subscribes to the terminal event, and event type information used to identify an end device event.

In this implementation, in the roaming scenario, the network accessing session control function object can monitor the terminal event.

Accordingly, according to the twelfth aspect, a communication device is provided. The communication device has a function of implementing the behavior of the communication device in the method of the eleventh aspect. The function may be implemented in hardware, or may be implemented in hardware running corresponding software. The hardware or software includes one or more modules corresponding to the above function.

In an exemplary implementation, the communication device includes: a pointer configured to direct a user plane function object to discover a service, where the service is a service corresponding to an event of a terminal to which the first application function object is subscribed; a receiving unit, configured to receive a service discovery notification transmitted by the user plane function object, where the service discovery notification is used to indicate that the service data has been discovered; a monitoring unit, configured to: when the terminal is unavailable, monitor an event of the terminal based on the service discovery notification; and a transmission unit, configured to: upon detecting a terminal device event, transmit a notification of the terminal device event to the network exposure function object or the first application function object.

In another possible implementation, the communication device includes a processor, the processor being capable of being connected to a memory, and reading and executing instructions in the memory to implement the aforementioned method.

Based on the same inventive concept, the principles and benefits of the device for solving the technical problem refer to the above possible implementations of the communication device method and the benefits obtained. Therefore, to implement the device, refer to the implementation of the method. Repetitive parts are again not described.

According to a thirteenth aspect, a communication method is provided, which includes: receiving a first message that is for a terminal event and which is transmitted by a control function object, where the first message is used to subscribe to the terminal device event, and the first message includes service description information and DNN/S-NSSAI data network name/single network name selection support information; sending a second message to a session management function object, where the second message is used to subscribe to a service discovery event, and the second message includes service description information; receiving a service discovery notification from the session management function object; activating a terminal event when the terminal is unavailable; and transmitting the tag's availability notification to the capability exposure node or application function object upon detecting that the tag is available.

In an implementation, sending a second message to the session management function object includes: sending a second message to the session management function object when the DNN/S-NSSAI of the session matches the DNN/S-NSSAI contained in the first message.

In another implementation, passing the second message to a session management function object includes: sending a subscription request to a local session management function object or a roaming session management function object; or passing the session context update request to a local session management function object or a roaming session management function object, where the session context update request is used to subscribe to the terminal device event.

According to a fourteenth aspect, a communication method is provided, which includes: receiving a second message for a terminal event from an AMF mobility management function entity; sending a third message to a UPF user plane function object, where the third message is used to indicate to discover a service, and the service is a service corresponding to the signed event of the terminal; receiving a service discovery notification from a user plane function object, where the service discovery notification is used to indicate the occurrence of service data; and transmitting a service discovery notification to a mobility management function entity.

In an implementation, receiving a second message for a terminal event from the mobility management function object includes: receiving a session context update request from the mobility management function object, where the session context update request is used to subscribe to the terminal device event.

In another implementation, sending a third message to a user plane function object includes: sending a third message to a user plane function object during or after session PDU deactivation, where the third message is used to indicate service discovery, and the service is a service corresponding to a subscribed endpoint event. devices.

According to a fifteenth aspect, a communication method is provided, which includes: receiving a first message from a control function object, where the first message is used to subscribe to an event of a terminal device, the first message includes service description information, and the service description information is used to indicate a service corresponding to end device event; receiving service information from a UPF user function entity, where the service information is determined based on the downlink data packet; and transmitting the event correlation information to the mobility management entity or the capability exposure entity based on at least the service information, where the event correlation information is used to determine the event reporting information.

In an implementation, before receiving the service information from the user function object, the method includes: sending a service information request to the user function object.

In another implementation, passing a service information request to a user function object includes: sending a service information request to a user function object in case of downlink data notification failure.

In yet another implementation, transmitting event correlation information to the mobility management entity or capability exposure entity, where the event correlation information is used to determine event reporting information, includes: transmitting event correlation information to the mobility management entity or capability exposure entity based on the service description information, and service information, where the event correlation information is used to determine the event reporting information.

In an exemplary implementation, the communication device includes: a pointer configured to direct a user plane function object to discover a service, where the service is a service corresponding to an event of a terminal to which the first application function object is subscribed; a receiving unit, configured to receive a service discovery notification transmitted by the user plane function object, where the service discovery notification is used to indicate that service data has been detected; a monitoring unit, configured to: when the tag is unavailable, monitor an event of the tag based on the service discovery notification; and a transmission unit, configured to: upon detecting a terminal device event, transmit a notification of the terminal device event to the network exposure function object or the first application function object.

In another possible implementation, the communication device includes a processor, the processor being capable of being connected to a memory, and for reading and executing an instruction in the memory, to implement the above method.

Based on the same inventive concept, the principles and benefits of the device for solving the technical problem refer to the above possible implementations of the communication device method and the benefits obtained. Therefore, to implement the device, refer to the implementation of the method. Repetitive parts are again not described.

According to a seventeenth aspect, a computer-readable storage medium is provided. A computer-readable storage medium stores instructions. When the instructions are executed on a computer, the computer is enabled to execute the method in accordance with the foregoing aspects or implementations thereof.

According to an eighteenth aspect, a computer program product including instructions is provided. When a computer program product is executed on a computer, the computer is configured to perform a method in accordance with the above aspects or implementations thereof.

Brief description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present invention or in the "prior art" section, the accompanying drawings necessary to describe the embodiments of the present invention or the prior art are briefly described below.

Fig. 1 is a diagram of an existing EPS architecture without roaming;

Fig. 2 is an interface architecture diagram in 3GPP EPS network architecture using SCEF;

Fig. 3a is a diagram of a non-roaming architecture based on a service interface in 5G;

Fig. 3b is a diagram of a non-roaming architecture based on a reference point in 5G;

Fig. 4 is a flowchart for configuring, with an application function object, a terminal event subscription for a network according to an embodiment of the present invention;

Fig. 5a is a flowchart for AF configuring a tag event subscription for UDM/PCF using NEF;

Fig. 5b is a flowchart of an example of configuring with AF a tag event subscription for UDR using PCF;

Fig. 5c is a flowchart of an example of configuring by AF a tag event subscription for UDR using NEF;

Fig. 6a is a flowchart of a communication method according to an embodiment of the present invention;

Fig. 6b is a flowchart of another communication method according to an embodiment of the present invention;

Fig. 6c-1 and FIG. 6c-2 are flowcharts of a specific example of executing a terminal event notification via NEF;

Fig. 7a-1 and FIG. 7a-2 are flowcharts of an example communication method;

Fig. 7b-1 and FIG. 7b-2 are flowcharts of another example of a communication method;

Fig. 7c-1 and FIG. 7c-2 are flowcharts of yet another example of a communication method;

Fig. 7d-1 of FIG. 7d-3 are flowcharts of yet another example of a communication method;

Fig. 7e-1 of FIG. 7e-3 are flowcharts of yet another example of a communication method;

Fig. 8 is a block diagram of a communication device according to an embodiment of the present invention;

Fig. 9a is a block diagram of another communication device according to an embodiment of the present invention;

Fig. 9b is a block diagram of another communication device according to an embodiment of the present invention;

Fig. 10 is a block diagram of another communication device according to an embodiment of the present invention;

Fig. 11 is a block diagram of another communication device according to an embodiment of the present invention;

Fig. 12 is a hardware diagram of a communication device according to an embodiment of the present invention;

Fig. 13 is a flowchart of another communication method according to an embodiment of the present invention;

Fig. 14a-1 in FIG. 14f are flowcharts of yet another example of a communication method;

Fig. 15 is a block diagram of another communication device according to an embodiment of the present invention;

Fig. 16 is a flowchart of another communication method according to an embodiment of the present invention;

Fig. 17-1 and FIG. 17-2 are flowcharts of yet another communication method according to an embodiment of the present invention;

Fig. 18-1 and FIG. 18-2 are flowcharts of yet another communication method according to an embodiment of the present invention;

Fig. 19-1 and FIG. 19-2 are flowcharts of yet another communication method according to an embodiment of the present invention; and

Fig. 20-1 and FIG. 20-2 are flowcharts of yet another communication method according to an embodiment of the present invention.

Implementation of the invention

The embodiments of the present invention will be described below with reference to the accompanying drawings in the embodiments of the present invention.

The technical solutions of the present invention can be applied to the non-roaming architecture of the EPS network shown in FIG. 1, or may be applied to a roaming architecture of an EPS network, or may be applied to a non-roaming architecture and a roaming architecture of a next generation network, for example, a non-roaming architecture based on a service-based interface in the fifth generation mobile communication network shown in FIG. 3a and in the non-roaming architecture based on the 5G reference point shown in FIG. 3b.

Using the 5G communication system architectures shown in FIG. 3a and fig. 3b, by way of example, the communication system mainly includes an access and mobility management function (AMF) object, a Session Management Function (SMF) object, a user plane function (UPF ), a network exposure function (NEF) object, and an application function (AF) object, and may further include a policy control function (PCF) object, a unified data repository function object , UDR) and a unified data management (UDM) function object. It should be noted that the function objects and function objects of the function shown in FIG. 3a may be the same as in FIG. 3b. In FIG. 3a, since the architecture is based on a service-based interface, a message sent by a function object to another function object must contain the identifier of the other function object. In FIG. 3b, since the architecture is based on a reference point, the communication between function objects is an interface message, and it is not necessary to pass the function object identifier.

The functions of the function objects in FIG. 3a and fig. 3b are as follows:

AMF entity: Mainly configured to handle signaling, such as functions such as access control, mobility control, join and detach, and gateway selection. When providing a service for a session at an AMF terminal, the entity provides a control plane storage resource for the session to store the session identifier, the entity's SMF identifier correlated with the session identifier, and the like.

SMF object: is mainly configured to manage the session and is specifically for user plane function object selection, user plane function object redirection, Internet protocol (IP) address assignment, channel setup, change and release, and control quality of service (QoS).

UPF object: configured to send and receive user data in the terminal device. The UPF entity may receive user data from the data network and transmit the user data to the end device using the network access device. As an alternative to the UPF, the entity may receive user data from the tag using a network access device and forward the user data to the data network. The transmission and resource scheduling functions in the UPF entity, which are used to provide the service to the terminal, are managed and controlled by the SMF entity.

NEF entity: mainly supports secure communication between 3GPP network and third party application. NEF can securely open network capabilities and an event for a third party application to improve the quality of service for applications. The 3GPP network can also securely obtain relevant data from a third-party application to improve the quality of network decision making. Additionally, the function object supports restoring structured data from a UDR or storing structured data in a UDR.

AF entity: mainly supports interaction with the 3GPP network to provide a service, such as influencing a data routing decision, a policy control function, or providing some services to the network side (where these services may or may not be performed by a 3rd ^party ). performed by a third party).

PCF object: mainly supports providing a unified policy framework for managing network behavior and providing a policy rule for a network control plane function, and is configured to obtain user subscription information related to a policy decision.

UDR object: is basically configured to store structured data. The stored content includes subscription data, policy data, external structured data, and application-specific data.

UDM object: basically configured to manage user's subscription information.

It should be noted that the above function objects are just names, and the names do not constitute any restrictions on the objects. For example, the session management function object could alternatively be replaced by "session management function" or another name. The session management function object may also correspond to an object that includes another function in addition to the session management function. The user plane function object may alternatively be replaced by "user plane function" or another name. The user plane function object may also correspond to an object that includes another function in addition to the user plane function. These descriptions are provided here and are not reproduced below.

The terminal accesses the network using a radio access network (RAN) or an access network (AN). A RAN device is basically a wireless network device in a 3GPP network, and an AN may be an access network device defined in a non-3GPP.

In the present disclosure, a terminal device may be a user equipment (UE), a portable terminal device, a laptop computer, a subscriber unit (subscriber unit), a cellular phone (cellular phone), a smartphone (smartphone), a wireless data card, a personal digital assistant ( personal digital assistant), tablet computer, wireless modem (modem), portable (handheld) device, laptop computer (laptop computer), cordless phone (cordless phone), wireless local loop station (wireless local loop (WLL), communication terminal type (machine type communication, MTC) or other device that can access the network.

A terminal device may communicate with a radio access network (RAN) using radio interface technology. The RAN device is generally configured to perform radio interface side functions such as radio resource management, QoS management, data compression and encryption. The access network may include a macro base station, a micro base station (also referred to as a small cell), a relay station, an access point, and the like. in various forms. In systems using different radio access technologies, the names of devices that perform the function of a base station may be different. For example, in a long term evaluation (LTE) system, a device is referred to as an evolved NodeB (evolved NodeB, eNB, or eNodeB), and in a 3rd ^generation (3G) system, the device is referred to as Node B (Node B) or the like.

An AN device allows connection and interaction between a terminal device and a 3GPP core network using non-3GPP technology. For example, non-3GPP technology is a network technology of wireless reliability (wireless fidelity, Wi-Fi), worldwide interoperability for microwave access (worldwide interoperability for microwave Access, WiMAX), code division multiple access (CDMA) or the like.

In the present disclosure, when a tag is in an unreachable state, it means that the network initiates a paging call for the tag but does not receive a response, the tag is in PSM mode, the tag is in MICO mode, and so on. The PSM mode of the terminal provides reduced power loss, and cannot be immediately available to receive service data that is sent to the terminal. In MICO mode, the end device can only initiate a connection. When the terminal is in this mode and the terminal is idle, the network considers the terminal to be unreachable.

In the present DDN disclosure, a failure may be that the network detects that the end device is in an unavailable state, or the data priority (i.e., allocation and retention priority (ARP) to initiate DDN) is not higher than the previous data priority. to initiate DDN.

In the present disclosure, a terminal event may be an event when various types of states or information are to be received from the network. For example, the technical solutions of the present invention may be applied to a communication scenario with a high latency requirement, and the tag event may be a tag availability event after a DDN failure. An application function object providing a communication service with a high latency requirement can maintain communication of a low latency service by subscribing to a terminal availability event after a DDN failure. Alternatively, the tag event may be a tag availability event or the like. The application function object sets up the associated application to provide the corresponding service. A terminal event subscription is a subscription to an event notification or a change to a subscribed event using a service operation.

It should be noted that the terms "system" and "network" can be used interchangeably in embodiments of the present invention. "Many" means two or more than two. In view of this, in the embodiments of the present invention, "multiple" can also be understood as "at least two". The term "and/or" describes a correlation relationship to describe related entities and represents that there may be three relationships. For example, A and/or B may represent the following three cases: only A exists, both A and B exist, and only B exists. Additionally, the "/" character typically indicates an "or" relationship between related entities.

Embodiments of the present invention provide a communication method and apparatus. A terminal event is subscribed to from the session control function object that manages the specific service; upon receiving the service discovery notification from the user plane function object, the session management function object instructs the access and mobility control function object to monitor the terminal event. Thus, a terminal event can be subscribed and tracked for a specific service in the 5G architecture.

In the present disclosure, subscribing to a tag event from the network, activating a tag event, and performing notification of a tag event basically include two procedures:

(1) First, an application function object having an installed application configures a terminal event for the network. There may be several ways to configure: AF configures an event for UDM/PCF using NEF, AF configures an event for UDR using PCF, AF configures an event for UDR using NEF, and so on. Detailed descriptions are provided below.

(2) The network fires the endpoint event and notifies the endpoint event. The following is a description using a detailed procedure of the communication method.

In particular, FIG. 4 is a flowchart for configuring, with an application function object, a terminal event subscription for a network according to an embodiment of the present invention. The method may include the following steps.

S101. The application function object passes the first message to the control function object. The control function object receives the first message from the application function object. The first message is used to subscribe to a terminal event, and the first message includes service description information.

The first message further includes at least one of the following information: a tag ID corresponding to the tag event, tag event type information, a data network name, segment information, and an application function service ID.

S102. The control function object allocates a terminal event correlation identifier.

S103. Pass at least one of the service description information, event correlation ID, terminal ID, terminal event type, data network name, segment information, and application function service ID to the unified data repository function object for storage.

S104. The unified data repository function object stores at least one piece of the above information.

5G is used as an example in this embodiment. For a service where it is necessary to monitor the state of a tag during service processing, the application function object providing the service may pass a first message to a control function object, where the first message is used to subscribe to the tag's event from the network. The control function object may be a UDM, PCF, NEF, or the like. The control function object receives the first message.

In this embodiment, one or more application function objects may subscribe to a tag event from the network. A terminal event subscribed to by multiple application function objects may correspond to the same service or to different services. For example, multiple application function objects may subscribe to the same tag event from multiple tags, or multiple application function objects may subscribe to different tag events from the same tag.

The first message contains service description information. The service description information is used to indicate the service corresponding to the terminal event.

The service description information may be service data description information. For example, the service description information may be any description information that can identify a service of a specific application function object, such as an IP triplet (destination IP address/IPv6 prefix), port number, IP number of an upper layer protocol (e.g., transmission protocol ), application ID, non-IP descriptor (non-IP), or Ethernet service description information.The destination IP address can be a destination IPv4 address, an IPv6 destination prefix, or an IPv6 destination address.

The corresponding function object can distinguish between a plurality of application function objects based on the service description information. Additionally, the first message further includes at least one of the following information: an identifier of the terminal device corresponding to the event of the terminal device, information about the type of event of the terminal device, a data network name (DNN), segment information, and an identifier application function service identifier (AF-service-ID).

A terminal device identifier may be an identifier (UE ID) of a single terminal device, or may be an identifier (group ID) of a plurality of terminal devices (ie, a group). The terminal identifier may be an identifier used to identify the user, such as a generic public subscription identifier (GPSI). The group identifier may be an external group identifier.

The tag event may be an event where different types of states or information are to be received from the network, or the tag event type may be various specific end events. The event type information is used to identify the terminal event. For example, the techniques of the present invention may be applied to a communication scenario with a high latency requirement, and the tag event type may be a tag availability event after a downlink data notification failure. For the case of tag availability after downlink data notification failure, when the application function object sends a downlink data packet to the tag through the network, if the tag is in the unreachable state, the network fires an event and monitors the state of the tag. When the terminal device transitions to the available state, the network reports the available state of the terminal device to the application function object using the control function object. A third party application can maintain a low latency overhead by subscribing to the endpoint's availability event after a DDN failure. Alternatively, the tag event type may be a tag availability event or the like. Alternatively, the terminal event type may be a service discovery event and is used to notify a subscriber from the network of the occurrence of a service. The event type information can be represented using the event type sequence number specified in the protocol, and the event type information is previously stored in the network device and the terminal device.

The DNN is used to identify the data network to which the user has access. The segment information may be a segment instance and/or ancillary information for selecting one network segment (single network slice selection assistance information, S-NSSAI). The S-NSSAI or segment instance is used to select a particular network segment, namely the core network such as SMF and UPF. The AF-service-ID is an application function service identifier, and the network side can obtain the DNN and segment information based on the identifier.

Additionally, the first message may further include a notification target address. The notification destination address may be a NEF identifier, an AF identifier, or an AF address.

The control function object receives the first message and processes the first message, which includes: checking, according to local policy, whether the application function object is authorized to fulfill the service request, whether the first message is valid, the number of times the application function object transmits the request, exceeds whether the limit is the number or frequency of requests, and so on. If the check passes, the control function object stores the above information and extracts the terminal event correlation identifier. The event correlation ID is used to identify the correlation relationship between the stub event and the function object that subscribes to the stub event. The event correlation ID may also be referred to as a notification correlation ID. Alternatively, the event correlation identifier may be a subscription correlation ID, and the subscription correlation identifier may be allocated by the AMF or SMF.

Additionally, the notification target address and the notification correlation ID may be used together. The notification target address and the notification correlation ID are used to correlate the notification received from the subscription event provider. One subscription is associated with one independent notification target address and notification correlation ID.

Additionally, if the management function object is NEF and the UDM/PCF is configuring a tag event for the network, the management function object may optionally send a tag event subscription message to the UDM/PCF. The message includes service description information, and further includes at least one of the following information: tag event ID corresponding to the tag event, tag event type information, DNN, segment information, and application function service ID.

In addition, what the control function object checks if a message is valid includes: checking if the network supports event monitoring, if a request should be accepted, and so on. When the check is passed, the control function object stores the above information.

In addition, the control function object may convey the above information to the UDR, and the UDR stores all the information.

In particular, the control function object transmits any one or a combination of any two, three, four, five, six, or seven of the service description information, event correlation ID, terminal ID, terminal event type information, data network name, segment information or an application function service identifier into a unified data repository function object for storage.

The following are configuration examples.

Example 1: AF configures an event for UDM/PCF using NEF.

Fig. 5a is a flowchart of an example of configuring, with AF, a terminal event subscription for UDM/PCF using NEF. The method may include the following steps.

S201. AF defines to subscribe to the "endpoint available after DDN failure" event from the network side. AF sends the first message to NEF, where the first message is used to subscribe to the tag's event. For example, in the system shown in Fig. 3a, the message may be Nnef_EventExposure_subscribe. The subscription message includes the following information: service description information, terminal ID (or group ID), AF ID, event type information, or DNN/S-NSSAI/AF-service-ID.

S202. The NEF performs a message handling process including: checking, according to local policy, whether the AF is authorized to make a service request, whether the message is valid, whether the application function object exceeds the number of times the application function object transmits the request, a limit or exceeds the request rate, and etc. If the check is passed, the NEF stores the following information: service description information, terminal ID (or group ID), event type information, and DNN/S-NSSAI/AF-service-ID. Additionally, the NEF allocates an event correlation identifier (eg, NEF reference ID) to the terminal event. The event correlation ID is used to identify the correlation relationship between the stub event and the function object that subscribes to the stub event. The event type information is used to identify the terminal event. Alternatively, the NEF may additionally store the following information: AF identifier or AF address. Based on the AF ID or AF address, the AF can be found and a message can be sent to the AF.

S203. The NEF sends a second message to the UDM/PCF where the second message is used to subscribe to the stub event. For example, in the system shown in Figure 3a, the message may be Nudm_EventExposure_subscribe/Npcf_EventExposure_subscribe. The subscription message includes the following information: service description information, terminal ID (or group ID), event type information, event correlation ID, and DNN/S-NSSAI/AF-service-ID. Optionally, the subscription message may further include an AF identifier or an AF address. The event type information is determined based on the event type information provided by the AF and may indicate the same event type or a new event type generated to support the event to which the AF is to subscribe.

In another embodiment, after receiving the event information from the AF, the NEF may send a message to the UDM and PCF separately. The message sent to the UDM may include a terminal identifier (or group identifier), event type information, and an event correlation identifier. The message sent to the PCF includes a terminal ID (or group ID), event type information, event correlation ID, service description information, and DNN/S-NSSAI/AF-service-ID. The event type information is determined based on the event type information provided by the AF and may indicate the same event type or a new event type generated to support the event to which the AF is to subscribe. Alternatively, the NEF may map the AF-service-ID to the DNN/S-NSSAI. In this case, the stored information is a DNN/S-NSSAI.

S204. The UDM/PCF checks if the message is valid, which includes: checking if the network supports event monitoring, if the request should be accepted, and so on. When the check is passed, the UDM/PCF stores the service description information, terminal ID (or group ID), AF ID, event type information, event correlation ID, and DNN/S-NSSAI/AF-service-ID. If the NEF can send the second message to the UDM and PCF separately, the information stored in the UDM is the tag ID (or group ID), the AF ID, the event type information, and the event correlation ID. The PCF stores service description information, terminal ID (or group ID), AF ID, event type information, event correlation ID, and DNN/S-NSSAI. Alternatively, the UDM may map the AF-service-ID to the DNN/S-NSSAI. In this case, the stored information is DNN/S-NSSAI.

S205. Alternatively, the UDM/PCF may send a third message in the UDR, where the third message is used to subscribe to the terminal event. For example, in the system shown in Figure 3a, the message may be Nudr_EventExposure_subscribe. The UDR stores the above information for subscribing to an end device event.

Example 2: AF configures an event for UDR using PCF.

Fig. 5b is a flowchart of an example of configuring with AF a tag event subscription for UDR using PCF. The method may include the following steps.

S301. AF defines to subscribe to the "endpoint available after DDN failure" event from the network side. The AF sends the first message to the PCF, where the first message is used to subscribe to the tag's event. For example, in the system shown in Figure 3a, the message may be Npcf_EventExposure_subscribe. The subscription message includes the following information: service description information, terminal ID (or group ID), AF ID, event type information, and DNN/S-NSSAI/AF-service-ID.

S302. The PCF processes the message, which includes: checking, according to local policy, whether the AF is authorized to fulfill the service request, whether the message is valid, whether the number of times the application function object sends the request exceeds a limit, or exceeds the request rate etc. If the check is passed, the PCF stores the following information: service description information, terminal ID (or group ID), event type information, and DNN/S-NSSAI/AF-service-ID. Additionally, the PCF allocates an event correlation identifier (eg, PCF reference ID) corresponding to the terminal event. The event correlation identifier is used to identify the correlation relationship between a terminal event and the function object that subscribes to the terminal event. The event type information is used to identify the terminal event. Alternatively, the subscribe message may further include an AF identifier or an AF address.

S303. Alternatively, the PCF sends a second message to the UDR, where the second message is used to subscribe to a tag event. For example, in the system shown in Figure 3a, the message may be Nudr_EventExposure_subscribe. The message includes the following information: service description information, terminal ID or group ID, event type information, PCF reference ID, and DNN/S-NSSAI/AF-service-ID. The subscription message may further include an AF identifier or an AF address.

S304. Alternatively, the UDR checks if the message is valid, which includes: checking if the network supports event monitoring, if the request should be accepted, and so on. When the check is passed, the UDR stores the following information: service description information, terminal ID or group ID, event type information, PCF reference ID, and DNN/S-NSSAI/AF-service-ID. The UDR may additionally store an AF identifier or an AF address.

Example 3: AF configures an event for a UDR using NEF.

Fig. 5c is a flowchart of an example of configuring by AF a tag event subscription for a UDR using NEF. The method may include the following steps.

S401. AF defines to subscribe to the "endpoint available after DDN failure" event from the network side. AF sends the first message to NEF, where the first message is used to subscribe to the tag's event. For example, in the system shown in Figure 3a, the message may be Nnef_EventExposure_subscribe. The message includes the following information: service description information, terminal ID or group ID, AF ID, event type information, and DNN/S-NSSAI/AF-service-ID.

S402. The NEF processes the message, which includes: checking, according to local policy, whether the AF is authorized to fulfill the service request, whether the message is valid, whether the application function object exceeds the number of times the application function object transmits the request, a limit or exceeds the request rate, and etc. If the check is passed, the NEF stores the following information: service description information, terminal ID or group ID, event type information, and DNN/S-NSSAI/AF-service-ID. Additionally, the NEF allocates an event correlation identifier (eg, NEF reference ID) to the terminal event. The event correlation id is used to identify the correlation relationship between the tag event and the function object that subscribes to the tag event. The event type information is used to identify the terminal event. The NEF may additionally store an AF identifier or an AF address.

S403. The NEF sends the second message to the UDR, where the second message is used to subscribe to the tag's event. For example, in the system shown in Fig. 3a, the message may be Nudr_EventExposure_subscribe. The message includes the following information: service description information, terminal ID or group ID, event type information, NEF reference ID, and DNN/S-NSSAI/AF-service-ID. The message may further include an AF identifier or an AF address. The event type information is determined based on the event type information provided by the AF and may indicate the same event type or a new event type generated to support the event to which the AF is to subscribe. Additionally, alternatively, the NEF may generate a plurality of events based on the event information sent by the AF and store the plurality of events in the UDR.

Alternatively, the UDR checks if the message is valid, which includes: checking if the network supports event monitoring, if the request should be accepted, and so on. When the check is passed, the UDR stores the following information: service description information, terminal ID (or group ID), event type information, NEF reference identifier, and DNN/S-NSSAI/AF-service-ID. The UDR may additionally store an AF identifier or an AF address.

According to the method in which the application function object configures the tag subscribed event for the network provided in this embodiment of the present invention, if the tag event is to be subscribed to a service, the application function object subscribes to the tag event from the control function object in the 5G network. In particular, when a service is running, the control function object subscribes to a terminal event from a particular session control function object. Thus, in the 5G architecture, it is possible to subscribe to an end device event and track it.

The following describes in detail the procedure for activating a terminal event and notifying a terminal device event by the network.

Fig. 6a is a flowchart of a communication method according to an embodiment of the present invention. The method may include the following steps.

S501. The management function object determines the session management function object based on at least one of the data network name, the segment information, and the service identifier of the application function.

Specifically, that the management function object determines the session management function object based on at least one of the data network name, the segment information, and the application function service identifier may be: the management function object determines the session management function object based on the name network, based on the segment information, based on the service ID of the application function, based on the data network name and segment information, based on the data network name and the service ID of the application function, based on the segment information and service ID of the application function, or based on data network name, segment information, and service ID of the application function.

S502. The management function object passes the first message to the session management function object. The first message is used to subscribe to a terminal event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the terminal event.

S503. The session control function object passes the second message to the user plane function object. The second message is used to direct the user plane function object to discover the service. The service is the service corresponding to the subscribed event of the end device. Additionally, in another implementation, the second message may be a service information request and is used to direct the user plane function object to report the service information. In this case, the execution of S504 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S504. Alternatively, when the received second message is used to direct the user plane function object to discover a service, the user plane function object discovers the service.

S505. The user plane function object sends a service discovery notification to the session control function object. The service discovery notification is used to indicate the occurrence of service data. The session management function object receives a service discovery notification. In another implementation, the service discovery notification may be service information, that is, service information in step S503. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S506. In response to the service discovery notification, the session control function object sends a notification that is intended to monitor a terminal event to the access and mobility control function object. Alternatively, a notification that is for monitoring a terminal event may include event correlation information, such as an event correlation identifier (reference ID NEF). Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

S507. The access and mobility control function object keeps track of the subscribed end device event.

S508. When a tag event is detected, the access and mobility control function object passes a tag event notification to a function object that subscribes to the tag event. The tag event notification includes at least one of the following information: a tag event identifier corresponding to the tag event, and an event correlation identifier for the tag event, where the event correlation identifier is used to identify a correlation relationship between the tag event and a function object that subscribes to the terminal device event. The function object that subscribes to the endpoint event receives the endpoint event notification.

5G is still used as an example in this embodiment. Based on the previous descriptions, if the AF intends to subscribe to a tag event from the network, the AF configures a tag event subscription for the control function object. The control function object or UDR stores a terminal identifier corresponding to a terminal event, terminal event type information, DNN, segment information, application function service identifier, service description information, and event correlation identifier.

When a session is established, a management function entity (eg, UDM/PCF) receives a correlation request sent by the SMF, where the correlation request is used to request that an event subscription be performed for the service corresponding to the session. The request may include a DNN, segment information, or an AF-service-ID. The control function object receives locally or from the UDR DNN the events of the terminal device configured in the above configuration procedure. The control function entity determines that the DNN included in the correlation request matches the DNN of the terminal event configured in the above configuration procedure. Alternatively, the management function entity obtains, locally or from the UDR, the terminal event segment information configured in the above configuration procedure and determines that the segment information used in the correlation request is compatible with the segment information configured in the previous configuration procedure (if the request includes the AF-service-ID, DNN, and segment information and can be retrieved using the AF-service-ID). In this case, the control function object defines an SMF that sends the correlation request and then sends the first message to the SMF, where the first message is used to subscribe to the tag's event.

Alternatively, after the session is established, the management function object receives the event of the terminal to which the AF is subscribed and determines the session that has the corresponding DNN and the corresponding segment information. The control function entity defines an SMF that is correlated with the session corresponding to the DNN and segment information, and may also actively send the first message to the SMF to subscribe to the terminal event.

The first message includes service description information. The service description information is used to indicate a service corresponding to an event of a terminal device, and may be further used to determine an application function object that provides a service to the terminal device.

Additionally, the first message may further include an event correlation identifier and tag event type information. The event correlation ID is used to identify the correlation relationship between the tag event and the function object that subscribes to the tag event, and the event type information is used to identify the tag event. The event correlation ID may be a reference ID generated by the control function object in the above configuration process. The reference ID is correlated with the AF ID. The tag event may be an event in which different types of states or information must be received from the network, or the tag event type may be various specific end events. For example, the tag event type includes a tag reachable event after a DDN failure, a tag reachable event, and the like. In addition, the event type may be represented by an event identifier. The event ID indicates the type of event that is being subscribed to, such as DDN failover availability.

The SMF receives the first message and sends the second message to the UPF. The second message is used to tell UPF to discover the service. The service is the service corresponding to the signed event of the terminal, that is, the service corresponding to the service description information. The second message may include a corresponding rule delivered by the SMF to the UPF, and the UPF discovers these services based on the rule.

The UPF receives the downlink data sent by the data network and detects, according to a packet detection rule (PDR), such as a packet filter or indicator, a service corresponding to the subscribed event of the terminal . The packet discovery rule includes service description information, such as an IP triplet.

For example, the rule may be that when the UPF does not store session access network tunnel information, the UPF needs to establish a user plane tunnel to transmit downlink data to the terminal. In this case, UPF sends a service discovery notification to the SMF. The service discovery notification is used to indicate the occurrence of service data. The service data is the service data corresponding to the service description information.

Further, in this embodiment, the service description information may be represented by event filter information. The event filter information is used to determine the match condition for the notification event. The event filter information includes event parameter types and event parameter value (s). The event parameter type may be service description information. The event parameter value may be specific service description information such as an IP triplet or an application ID.

The SMF receives a service discovery notification and, in response to the service discovery notification, sends a notification that is for monitoring a terminal event to the AMF.

AMF detects the state of the end device.

An example is used where the endpoint event is the endpoint availability event after a DDN failure. When it detects that an endpoint is in an unreachable state, the AMF or SMF fires an endpoint event and monitors the event of the endpoint it subscribes to. When a terminal is in the unreachable state, it means that the network initiates a page for the terminal but does not receive a response, the terminal is in PSM mode, or the terminal is in MICO mode.

When the AMF detects that an end device is online, for example, the end device initiates a tracking area update (TAU) or service request, the AMF passes the end device's event notification to a function object that subscribes to the event. terminal device. The tag event notification includes at least one of the following information: a tag event identifier corresponding to the tag event, and an event correlation identifier for the tag event, where the event correlation identifier is used to identify a correlation relationship between the tag event and a function object that subscribes to the terminal device event. The function object that subscribes to the endpoint event receives the endpoint event notification.

If one AF subscribes to the same tag event from a plurality of tags, the AF that subscribes to the tag event may be allocated based on the tag's ID in the tag's event notification. If multiple AFs subscribe to multiple end events from the same tag, the AFs that subscribe to the tag's event may differ from each other based on the event correlation IDs in the end event notifications. If multiple AFs subscribe to multiple end events from multiple tags, the AFs that subscribe to the end events may differ from each other based on the tag IDs and event correlation IDs that are in the end event notifications. Therefore, one or more application function objects may provide a service to a terminal device. When subscribing to a tag event, the service description information is used to indicate the service corresponding to the tag event, so that the application function objects that subscribe to the tag event may differ from each other.

The function object that subscribes to the stub event can be SMF, AF, or NEF.

If the tag event type is a tag availability event after a DDN failure, after receiving a tag event notification (notification that a tag is available), the AF may retransmit the downlink data to the tag.

Event reporting information may be used to identify information about a reported event. In this embodiment, the event reporting information may be used to describe an availability event after a DDN failure reported by the AMF or SMF.

Fig. 6b is a flowchart of a communication method according to an embodiment of the present invention. The method may include the following steps.

S501'. The management function object determines the session management function object based on at least one of the data network name, the segment information, and the service identifier of the application function.

Specifically, that the management function object determines the session management function object based on at least one of the data network name, the segment information, and the application function service identifier may be: the management function object determines the session management function object based on the name network, based on the segment information, based on the service ID of the application function, based on the data network name and segment information, based on the data network name and the service ID of the application function, based on the segment information and service ID of the application function, or based on data network name, segment information, and service ID of the application function.

S502'. The management function object passes the first message to the session management function object. The first message is used to subscribe to a terminal event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the terminal event.

S503'. The session control function object passes the second message to the user plane function object. The second message is used to direct the user plane function object to discover the service. The service is the service corresponding to the subscribed event of the end device. Additionally, in another implementation, the second message may be a service information request and is used to direct the user plane function object to report the service information. In this case, the execution of S504' is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S504'. Alternatively, when the received second message is used to direct the user plane function object to discover a service, the user plane function object discovers the service.

S505'. The user plane function object sends a service discovery notification to the session control function object. The service discovery notification is used to indicate the occurrence of service data. The session management function object receives a service discovery notification. In another implementation, the service discovery notification may be service information, that is, service information in step S503'. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

To implement the above steps, respectively, refer to steps S501 to S505 in the embodiment shown in FIG. 6a. The details are again not described here.

S506'. The session control function object sends a terminal service occurrence notification to the network exposure function object in response to the service discovery notification.

In the preceding steps, the session control object receives a subscription to the terminal event from the control function object. In this case, after receiving the service discovery notification sent by the user plane function object and determining that the terminal is not available, the session control function object sends a service occurrence notification of the terminal to the NEF.

S507'. Upon receipt of a tag availability notification, the network access function object passes the tag event notification to a function object that subscribes to the tag event. The tag event notification includes at least one of the following information: a tag event identifier corresponding to the tag event, and an event correlation identifier for the tag event, where the event correlation identifier is used to identify a correlation relationship between the tag event and a function object that subscribes to the terminal device event. The function object that subscribes to the endpoint event receives the endpoint event notification.

Since the NEF has previously received the tag service occurrence notification from the SMF, when the NEF receives the tag availability notification sent by the AMF, the NEF sends the tag event notification to the AF. According to the communication method provided in this embodiment of the present invention, the SMF receives a tag event subscription, notifies the NEF when the tag is unavailable, and sends the tag event notification to the AF when the NEF receives the tag availability notification that is sent by the AMF . Thus, a terminal event can be subscribed and notified for a specific service in the 5G architecture.

Fig. 6c-1 and FIG. 6c-2 is a flowchart of a specific example of performing a terminal event notification with NEF.

S501''. The UDM/PCF determines the target SMF based on the DNN/S-NSSAI/AF-service-ID and subscribes to a terminal event from the SMF and AMF.

The DNN/S-NSSAI/AF-service-ID may be obtained from the UDR or may be stored locally.

A UDM or PCF can subscribe to a stub event from AMF and SMF in the following two ways:

Method 1: The UDM or PCF sends event 1 (eg, UE availability event after DDN failure) and event correlation ID to the AMF, and sends event 2 (eg, service discovery event), event correlation ID, and service description information to the SMF.

Method 2: UDM sends event 1 (eg, UE availability event after DDN failure) and event correlation ID to AMF, and PCF sends event 2 (eg, service discovery event) event correlation ID, service description information for SMF.

S502a''. The UDM/PCF sends the first AMF message.

S502b''. The UDM/PCF sends a second message (eg Nsmf_EventExposure) to the target SMF.

The second message includes service description information, event type information, and event correlation identifier (eg, NEF reference identifier), and may further include information such as NEF identifier. In this example, the event type is a service discovery event.

SMF/AMF receives the first message.

Specifically, after receiving the service discovery event and the service description information, the SMF correlates the service discovery event with the service description information. If they are sent together (sent in the same message), it means that they are correlated with each other. Alternatively, if the service description information is transmitted in the service discovery event subscription message, this indicates that they are correlated with each other.

S503''. The SMF sends a service discovery message to the UPF in the session setup or change procedure N4. The service discovery message includes service description information.

In particular, when receiving a notification from UPF that data corresponding to the service description information has been detected, the SMF can determine the event to which the data corresponds, trigger the event, and hence pass the event's correlation identifier to the corresponding NEF.

The UPF discovers the corresponding service based on the service discovery message, that is, it discovers the service corresponding to the service description information.

Additionally, in another implementation, the service discovery message may be a service information request used to direct a user plane function object to report service information. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S504''. The AMF sends the UE unavailability information to the SMF.

The AMF may send UE unreachability information to the SMF when receiving service data sent by another AF and detecting that the UE is unavailable. Alternatively, the AMF sends the UE unreachability information to the SMF upon receiving the service data sent by the AF and detecting a DDN data failure.

Alternatively, S504'' may be any step before S506''.

S505''. The AF transmits a downlink data packet to the terminal.

S506''. The UPF sends a Service Discovery Notification to the SMF.

The UPF detects, according to the packet discovery rule, that the downlink data packet is a service corresponding to the subscribed event of the terminal.

When UPF does not store session access tunnel information, the user plane tunnel must be established and UPF sends a service discovery notification to the SMF. The service discovery notification is used to indicate that the occurrence of service data has been detected.

In particular, the service corresponding to the subscribed event of the terminal is the service corresponding to the service description information. The packet discovery rule includes service description information. For example, the service description information is IP quintuple information, and the UPF detects the received downlink data packet based on the IP quintuple information. When a downlink data packet corresponding to the five-fold information IP is detected, it is determined that the occurrence of service data has been detected.

In another implementation, the service discovery notification may be service information, that is, service information in step S503''. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S507''. The SMF sends an event notification to the NEF.

Specifically, the SMF notifies the NEF that a stub event has occurred.

S508a''. If the SMF reports the event to the NEF when the UE is unavailable, this step is performed and the NEF records the event.

S508b''. If the SMF reports an event to the NEF upon service discovery at any time, the NEF records the event and the NEF determines that the UE is not available.

S509''. The end device establishes a connection to the network.

For example, a terminal initiates a TAU request or a service request on the network.

S510''. The AMF sends a UE availability event notification to the NEF.

S511''. The NEF sends the event notification of the UE to the AF.

Specifically, according to S508a'', when a UE availability event is received, the event is transmitted to the AF based on the entry. For example, the UE availability event is transmitted to the recorded event AF corresponding to the service.

According to S508b'', the entry is deleted when the UE becomes available. If the UE is not available, the entry is kept; when a UE availability event is received, the event is transmitted to the AF based on the entry. For example, the UE availability event is transmitted to the recorded event AF corresponding to the service.

The following further describes examples of the above communication method in more detail with reference to specific communication scenarios.

Example 1: AMF receives the endpoint event subscription from the SMF and performs event monitoring and notification.

Fig. 7a-1 and FIG. 7a-2 are flowcharts of an example communication method. In this example, the SMF tells the AMF to listen for an end device event. Specifically, during or after a session is established, the UDM/PCF performs the following procedure:

S601. The UDM/PCF determines the target SMF based on the DNN/S-NSSAI/AF-service-ID. The DNN/S-NSSAI/AF-service-ID may be obtained from the UDR or may be stored locally.

S602. The UDM/PCF sends the first message (eg Nsmf_EventExposure) to the target SMF. The first message includes service description information, event type information, and event correlation identifier (eg, NEF reference identifier), and may further include information such as NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

The SMF receives the first message.

Specifically, after the SMF receives the DDN failure availability event and the service description information, the SMF correlates the DDN failure availability event with the service description information. If they are sent together (sent in the same message), it means that they are correlated with each other. Alternatively, if the service description information is carried in the availability event subscription message after a DDN failure, this indicates that the two parameters are correlated with each other.

S603. The SMF sends a service discovery message to the UPF in the session setup or change procedure N4. The service discovery message includes service description information.

In particular, when receiving a notification from the UPF that data corresponding to the service description information has been detected, the SMF may determine the event to which the data corresponds, trigger the event, and hence pass the event correlation identifier to the corresponding AMF. Additionally, in another implementation, the service discovery message may be a service information request used to direct a user plane function object to report service information. In this case, the execution of S605 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

The UPF discovers the corresponding service based on the service discovery message, that is, it discovers the service corresponding to the service description information.

S604. The AF transmits a downlink data packet to the terminal.

S605. Alternatively, when the received service discovery message is used to instruct the user plane function object to discover the service, the UPF detects, according to the packet discovery rule, that the downlink data packet is a service corresponding to the subscribed event of the terminal.

When UPF does not store session access tunnel information, the user plane tunnel must be established and UPF sends a service discovery notification to the SMF. The service discovery notification is used to indicate that the occurrence of service data has been detected.

In particular, the service corresponding to the subscribed event of the terminal is the service corresponding to the service description information. The packet discovery rule includes service description information. For example, the service description information is an IP triplet, and the UPF detects a received downlink data packet based on the IP triplet. When a downlink data packet corresponding to an IP triplet is detected, it is determined that the occurrence of service data has been detected.

S606. The SMF sends a second message (eg, Namf_CommunicationN1N2MessageTransfer) to the AMF in response to a service discovery notification sent by UPF. The second message includes event type information and an event correlation identifier (eg, NEF reference identifier) and may further include an NEF identifier. The NEF identifier is used by the AMF to send a notification to the NEF corresponding to the NEF identifier.

Alternatively, S606, the event type information and the event correlation ID may be transmitted in different messages. For example, the SMF could add the NEF reference identifier to Namf_CommunicationN1N2MessageTransfer and add event type information to Namf_EventExposure_Subscribe. Additionally, the transmission order of the two messages is not limited. In another implementation, the service discovery notification may be service information, that is, service information in step S603. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S607. When the AMF detects that the endpoint is unreachable, the AMF sends a response message (eg, Namf_CommunicationN1N2MessageTransfer) to the SMF to notify the SMF of the DDN failure.

S608. The SMF then sends a DDN failure indication to UPF.

S609. When AMF determines that an endpoint is unreachable, AMF sets or fires an availability event after a DDN failure and AMF starts monitoring the reachability state of the endpoint.

S610. The end device establishes a connection to the network. For example, the terminal initiates a TAU request or a network service request.

S611. If it is determined that an availability event after a DDN failure has been set locally, the AMF sends a stub event notification (eg, Namf_EventExposure_Notify) to the NEF. The tag event notification includes at least one of the following information: a tag device identifier and an event correlation identifier (eg, reference ID NEF).

S612. The NEF sends a tag event notification (eg, Namf_EventExposure_Notify) to the AF based on the tag ID and/or the reference ID of the NEF.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal.

Example 2: SMF performs event monitoring and notification.

Fig. 7b-1 and FIG. 7b-2 are flowcharts of another example of a communication method. Unlike the example shown in 7a, in this example the AMF monitors the stub availability event and passes the stub availability notification to the session management function object when the stub is available, in which the notification is used to instruct the SMF to monitor the stub availability event after a failure. DDN. Specifically, during or after a session is established, the UDM/PCF performs the following procedure:

S701. The UDM/PCF determines the target SMF based on the DNN/S-NSSAI/AF-service-ID. DNN/S-NSSAI/AF-service-ID is obtained from UDR or stored locally.

S702. The UDM/PCF sends the first message (eg Nsmf_EventExposure) to the target SMF. The first message includes service description information, event type information, and event correlation identifier (eg, NEF reference identifier), and may further include information such as NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

S703. The SMF sends a service discovery message to the UPF in the session setup or change procedure N4. The service discovery message is used to instruct UPF to discover the service corresponding to the subscribed tag event, that is, the service corresponding to the service description information. Additionally, in another implementation, the service discovery message may be a service information request used to direct a user plane function object to report service information. In this case, the execution of S705 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S704. The AF transmits a downlink data packet to the terminal.

S705. Alternatively, when the received service discovery message is used to indicate to the user plane function entity to discover the service, the UPF determines, according to the packet discovery rule, that the downlink data packet is the service corresponding to the subscribed terminal event. When a user plane tunnel needs to be established, the UPF sends a service discovery notification to the SMF. The service discovery notification is used to indicate that the occurrence of service data has been detected.

S706. The SMF sends a second message (eg, Namf_CommunicationN1N2MessageTransfer) to the AMF in response to a service discovery notification sent by UPF. The second message is used to subscribe to the tag's event, and the second message includes information about the event type. The event type is an endpoint availability event.

S707. If the end device is found to be unreachable, the AMF sends a response message (eg, Namf_CommunicationN1N2MessageTransfer) to the SMF. The response message is used to indicate that the end device is not available.

S708. The SMF then sends a DDN failure indication to UPF.

S709. AMF fires an end device availability event.

S710. When the SMF determines that an endpoint is unreachable (for example, the endpoint is in the PSM state or the endpoint is in the MICO state), the SMF raises an availability event after a DDN failure.

The end device initiates a connection to the network. For example, the terminal initiates a TAU request or service request to the network.

S711. If it is determined that the SMF is subscribing to a tag availability reporting event, the AMF sends the first tag event notification (eg, Namf_EventExposure_Notify) to the SMF. The first endpoint event notification is used to notify that the endpoint is available.

S712a. After determining that a DDN failover availability event has been set, the SMF sends a second stub event notification to the NEF. The second tag event notification includes at least one of the following information: a tag device identifier and a tag event event correlation identifier.

S713. The NEF sends a second tag event notification to the AF based on the tag ID and/or the event correlation ID.

As an alternative to S712a and S713, S712b may alternatively be performed such that the SMF may send a second tag event notification to the AF. The second tag event notification includes at least one of the following information: an AF ID, a tag ID, and an event correlation ID for the tag event.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal.

Example 3: The SMF discovers the service and the AMF receives the tag's event subscription from the UDM/PCF and performs event discovery and notification.

Fig. 7c-1 and FIG. 7c-2 are flowcharts of yet another example of a communication method. The specific procedure is described as follows:

S801. The UDM/PCF (SMF-PCF) determines the target SMF based on the DNN/S-NSSAI/AF-service-ID. DNN/S-NSSAI/AF-service-ID is obtained from UDR or stored locally. In addition, the UDM/PCF (AMF-PCF) determines the AMF based on the UE ID.

S802. The UDM/PCF (AMF-PCF) sends the first message (eg, Nsmf_EventExposure) to the AMF during the UE registration process or any other time the terminal is in the registration state. The first message includes event type information and an event correlation identifier (eg, NEF reference identifier) and may further include an NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

During or after session establishment, the UDM/PCF (SMF-PCF) sends a second message (eg, an Nsmf_EventExposure overhead message) to the target SMF. The second message includes service description information and an event correlation identifier (eg, reference ID NEF).

AMF-PCF is an AMF-correlated PCF and is configured to provide access and mobility related policy and terminal policy to AMF. The SMF-PCF is a PCF correlated with an SMF and is configured to provide a session-related policy to the SMF. AMF-PCF and SMF-PCF may be the same function object or may be independent function objects.

S803. The SMF sends a service discovery message to the UPF in the session setup or change procedure N4. The service discovery message is used to instruct UPF to discover the service corresponding to the subscribed tag event, that is, the service corresponding to the service description information. Additionally, in another implementation, the service discovery message may be a service information request used to direct the user plane function object to report information to the service. In this case, the execution of S805 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S804. The AF transmits a downlink data packet to the terminal.

S805. Alternatively, when the received second message is used to instruct the user plane function entity to discover a service, the UPF receives the downlink data packet and determines, according to the packet discovery rule, that the downlink data packet is the service corresponding to the subscribed terminal event. When a user plane tunnel needs to be established, the UPF sends a downlink data notification to the SMF. The downlink data notification is used to indicate the occurrence of service data. In another implementation, the downlink data notification may be service information, that is, service information in S803. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S806. The SMF sends a third message (eg, Namf_CommunicationN1N2MessageTransfer) to the AMF in response to the service discovery notification sent by UPF. The third message includes a reference NEF identifier and may further include a NEF identifier. It should be noted that in this embodiment, the SMF activates, using the third message, an AMF to track the tag event. In this case, the SMF instructs the AMF to start monitoring the tag event, and the UDM/PCF has configured, using the first message, the AMF to monitor the tag event. That is, configuring terminal event monitoring and service discovery corresponding to service description information may be independent processes and may be indicated in different messages. Alternatively, the third message may include event correlation information, such as an event correlation identifier. Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

In the above procedure, the event subscription message and event monitoring notification are sent by different function objects or SMFs. The AMF first receives the availability event subscription information after the DDN fails, and then the AMF receives the event monitoring notification, where the event monitoring notification includes the NEF reference identifier. In this case, the AMF may associate the monitoring notification with the event. S807. When the AMF detects that the terminal is unreachable and the downlink data notification fails, the AMF sends a response message (eg, Namf_CommunicationN1N2MessageTransfer) to the SMF to notify the SMF of the DDN failure.

S808. The SMF then sends a DDN failure indication to UPF.

S809. When the AMF determines that the UE is unavailable (eg, the UE is in the PSM state or the UE is in the MICO state), the AMF sets or fires the appropriate terminal availability event after a DDN failure based on the NEF of the reference ID. S810. The end device establishes a connection to the network. For example, the terminal initiates a TAU request or service request to the network.

S811. If it is determined that a stub availability event after a DDN failure is set locally, AMF sends a stub event notification (eg, Namf_EventExposure_Notify) to the NEF. The tag event notification includes at least one of the following information: a tag ID and a NEF reference ID.

In this example, one or more AFs are subscribed to a stub event and the stub event is correlated with the AMF in basically two ways: (1) in one way, one DDN failover availability event is subscribed from the AMF for only one UE, and the event can have different anchors. NEF IDs so that the AMF can report the event to different AFs using the NEFs. (2) In another way, each AF serving the UE may subscribe to a DDN failover availability event from the AMF for each event, so that each DDN failover availability event may correspond to different AFs.

Alternatively, the AMF may directly report the event to the AF.

S812. The NEF sends a tag event notification (eg, Namf_EventExposure_Notify) to the AF based on the tag ID and/or event correlation ID.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal. According to the communication method provided in this embodiment of the present invention, a terminal event is subscribed from a session control function object that manages a particular service; upon receiving the service discovery notification from the user plane function object, the session control function object instructs the access and mobility control function object to track the terminal event. Thus, a terminal event can be subscribed and tracked for a specific service in the 5G architecture.

Example 4: In a roaming scenario, the V-SMF performs event monitoring and notification.

Fig. 7d-1 of FIG. 7d-3 are flowcharts of yet another example of a communication method. Unlike the example shown in FIG. 7b-1 and FIG. 7b-2, the local session management function (H-SMF) entity forwards the terminal availability event subscription message after DDN failure to the roaming session management function (V-SMF) entity, and then the V-SMF performs event monitoring and notification. Specifically, during or after a session is established, the UDM/PCF performs the following procedure:

S701'. The UDM/PCF determines the target H-SMF based on the DNN/S-NSSAI/AF-service-ID. DNN/S-NSSAI/AF-service-ID is obtained from UDR or stored locally.

S702a'. The UDM/PCF sends the first message (eg, Nsmf_EventExposure) to the target H-SMF. The first message includes service description information, event type information, and event correlation identifier (eg, NEF reference identifier), and may further include information such as NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

S702b'. The H-SMF sends the first message to the V-SMF.

S703'. The V-SMF sends a service discovery message to a roaming user plane function (V-UPF) entity in a procedure for setting up or changing a session N4. The service discovery message is used to direct the V-UPF to discover the service corresponding to the subscribed event of the terminal, that is, the service corresponding to the service description information. Additionally, in another implementation, the service discovery message may be a service information request used to direct a user plane function object to report service information. In this case, the execution of S705' is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S704'. The AF transmits a downlink data packet to the terminal.

S705'. Alternatively, when the received service discovery message is used to instruct the user plane function entity to discover the service, the V-UPF determines, according to the packet discovery rule, that the downlink data packet is the service corresponding to the subscribed terminal event. When a user plane tunnel needs to be established, the V-UPF sends a service discovery notification to the V-SMF. The service discovery notification is used to indicate that the occurrence of service data has been detected. In another implementation, the service discovery notification may be service information, that is, service information in step S703'. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S706'. The V-SMF sends a second message (eg, Namf_CommunicationN1N2MessageTransfer) to the AMF in response to the service discovery notification sent by the V-UPF. The second message is used to subscribe to the tag's event, and the second message includes information about the event type. The event type is an endpoint availability event. Alternatively, the second message may include event correlation information, such as an event correlation identifier. Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

S707'. If the terminal is found to be unreachable, the AMF sends a response message (eg, Namf_CommunicationN1N2MessageTransfer) to the V-SMF. The response message is used to indicate that the end device is not available.

S708'. The V-SMF then sends a DDN failure indication to the V-UPF.

S709'. AMF fires an end device availability event.

S710'. When the V-SMF determines that the end device is not available (for example, the end device is in the PSM state or the end device is in the MICO state), the V-SMF raises an availability event after a DDN failure.

The end device initiates a connection to the network. For example, the terminal initiates a TAU request or service request to the network.

S711'. If it is determined that the V-SMF is subscribing to a tag availability reporting event, the AMF sends the first tag event notification (eg, Namf_EventExposure_Notify) to the V-SMF. The first endpoint event notification is used to notify that the endpoint is available.

S712a'. Upon determining that the DDN failover availability event has been set, the V-SMF sends a second stub event notification to the NEF. The second tag event notification includes at least one of the following information: a tag device identifier and a tag event event correlation identifier.

S713'. The NEF sends a second tag event notification to the AF based on the tag ID and/or event correlation ID.

As an alternative to S712a' and S713', S712b', it may alternatively be that the V-SMF may send a second terminal event notification to the AF. The second tag event notification includes at least one of the following information: an AF ID, a tag ID, and an event correlation ID for the tag event.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal.

Example 5: In a roaming scenario, the V-SMF discovers a service and the AMF receives a terminal event subscription from the UDM/PCF and performs event discovery and notification.

Fig. 7e-1 of FIG. 7e-3 are flowcharts of yet another example of a communication method. The specific procedure is described as follows:

S801'. The UDM/PCF (SMF-PCF) determines the target H-SMF based on the DNN/S-NSSAI/AF-service-ID. DNN/S-NSSAI/AF-service-ID is obtained from UDR or stored locally. In addition, the UDM/PCF (AMF-PCF) determines the AMF based on the UE ID.

S802a'. The UDM/PCF (AMF-PCF) sends the first message (eg, Nsmf_EventExposure) to the AMF during the registration process of the tag, or any other time the tag is in the registration state. The first message includes event type information and an event correlation identifier (eg, NEF reference identifier) and may further include an NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

S802b'. During or after session establishment, the UDM/PCF (SMF-PCF) sends a second message (eg, Nsmf_EventExposure overhead message) to the target H-SMF. The second message includes service description information and an event correlation identifier (eg, reference ID NEF).

AMF-PCF is a PCF function correlated with AMF and is configured to provide AMF with access and mobility related policy and terminal policy. The SMF-PCF is a PCF correlated with an H-SMF and is configured to provide a session related policy to the H-SMF. AMF-PCF and SMF-PCF may be the same function object or may be independent function objects.

S802b''. The H-SMF sends the third message to the V-SMF. The third message includes service description information and an event correlation identifier.

S803'. The V-SMF sends a service discovery message to the V-UPF in the session setup or change procedure N4. The service discovery message is used to direct the V-UPF to discover the service corresponding to the subscribed event of the terminal, that is, the service corresponding to the service description information. Additionally, in another implementation, the service discovery message may be a service information request used to direct a user plane function object to report service information. In this case, the execution of S805' is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S804'. The AF transmits a downlink data packet to the terminal.

S805'. Alternatively, when the received service discovery message is used to instruct a user plane function entity to discover a service, the V-UPF receives the downlink data packet and determines, according to the packet discovery rule, that the downlink data packet is the service corresponding to the subscribed endpoint event. devices. When a user plane tunnel needs to be established, the V-UPF sends a downlink data notification to the V-SMF. The downlink data notification is used to indicate the occurrence of service data.

S806'. The V-SMF sends a fourth message (eg, Namf_CommunicationN1N2MessageTransfer) to the AMF in response to the service discovery notification sent by the V-UPF. The fourth message includes a reference NEF identifier and may further include a NEF identifier. It should be noted that in this embodiment, the V-SMF activates, using the fourth message, an AMF to track a terminal event. In this case, the V-SMF instructs the AMF to start monitoring the tag event, and the UDM/PCF has configured, using the first message, the AMF to monitor the tag event. That is, configuring terminal event monitoring and service discovery corresponding to service description information may be independent processes and may be indicated in different messages.

In the above procedure, the event subscription message and event monitoring notification are sent by different function objects or V-SMFs. The AMF first receives the availability event subscription information after the DDN fails, and then the AMF receives the event monitoring notification, where the event monitoring notification includes the reference NEF ID. In this case, the AMF may associate the monitoring notification with the event. In another implementation, the service discovery notification may be service information, that is, service information in step S803'. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

Alternatively, the fourth message may include event correlation information, such as an event correlation identifier (reference ID NEF). Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

S807'. When the AMF detects that the terminal is unavailable and downlink data notification failure, the AMF sends a response message (eg, Namf_CommunicationN1N2MessageTransfer) to the V-SMF to notify the V-SMF of the DDN failure.

S808'. The V-SMF then sends a DDN failure indication to the V-UPF.

S809'. When the AMF determines that the UE is unavailable (eg, the UE is in the PSM state or the UE is in the MICO state), the AMF sets or fires the appropriate terminal availability event after a DDN failure based on the NEF reference ID.

S810'. The end device establishes a connection to the network. For example, the terminal initiates a TAU request or a service request to the network.

S811'. If it is determined that a stub availability event after a DDN failure is set locally, AMF sends a stub event notification (eg, Namf_EventExposure_Notify) to the NEF. The tag event notification includes at least one of the following information: a tag ID and a NEF reference ID.

In this example, one or more AFs are subscribed to an endpoint event, and the endpoint event is correlated with the AMF in two main ways: (1) one way, one DDN failover event is subscribed from the AMF for only one UE, and the event can have different reference IDs of the NEF so that the AMF can report the event to different AFs using the NEF. (2) In another way, each AF serving the UE may subscribe to a DDN failover availability event from the AMF for each event, so that each DDN failover availability event may correspond to a different AF.

Alternatively, the AMF may directly report the event to the AF.

S812'. The NEF sends a tag event notification (eg, Namf_EventExposure_Notify) to the AF based on the tag ID and/or event correlation ID.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal. According to the communication method provided in this embodiment of the present invention, a terminal event is subscribed from a session control function object that manages a specific service; upon receiving the service discovery notification from the user plane function object, the session control function object instructs the access and mobility control function object to track the terminal event. Thus, a terminal event can be subscribed and tracked for a specific service in the 5G architecture.

The foregoing details the methods in the embodiments of the present invention. Below are devices in embodiments of the present invention.

Fig. 8 is a diagram of a communication device according to an embodiment of the present invention. The communication device may be a control function object described in the above communication system, and may be a UDM, PCF, NEF, or the like, in particular. In particular, the communication device 1000 may include a receiving unit 11 and a transmitting unit 12.

The processing unit 11 is configured to determine the session management function object based on at least one of the data network name, the segment information, and the service ID of the application function.

The transmission unit 12 is configured to send a first message to a session control function object, where the first message is used to subscribe to a tag event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the tag event.

In the implementation, the service description information is further used to determine the application function object that provides the service to the terminal.

In another implementation, the first message further includes an event correlation identifier and event type information for the tag event, the event correlation identifier is used to identify a relationship between the tag event and a function object that subscribes to the tag event, and the event type information is used to end device event identification.

In yet another implementation, the sender is further configured to send a second message to an access and mobility control function object, where the second message is used to subscribe to a tag event, and the second message includes an event correlation identifier and event type information for the tag event. , the event correlation identifier is used to identify the relationship between the tag event and the function object that subscribes to the tag event, and the event type information is used to identify the tag event.

In yet another implementation, the communications device 1000 may further include a receiving unit 13.

The receiving unit 13 is configured to receive a third message from an application function object, where the third message is used to subscribe to a tag event, and the third message includes service description information.

In yet another implementation, the third message further includes at least one of the following information: a tag identifier corresponding to the tag event, tag event type information, a data network name, segment information, and an application function service identifier.

In yet another implementation, the receiving unit 13 is further configured to receive a third message forwarded by the network exposure function object.

In yet another implementation, the transmission unit 12 is further configured to transmit at least one of the service description information, the event correlation ID, the tag ID, the tag event type, the data network name, the segment information, and the application function service ID to the object. unified data repository functions for storage.

In yet another implementation, the processing unit 11 is further configured to obtain at least one of service description information, an event correlation ID, a terminal ID, event type information for a terminal event, a data network name, segment information, and a service ID. application functions locally or from the unified data repository function object.

In yet another implementation, the receiving unit 13 is further configured to receive a terminal event notification from an access and mobility control function object or a session management function object. The transmitting unit 11 is further configured to transmit the terminal event notification to the application function object.

In yet another implementation, the tag event type includes a tag availability event after a downlink data notification failure.

Fig. 9a is a block diagram of another communication device according to an embodiment of the present invention. The communication device may be an object of the access and mobility control function described in the above communication system. Specifically, the communication device 2000a may include a receiving unit 21a, a monitoring unit 22a, and a transmission unit 23a.

The receiving unit 21a is configured to receive the first message sent by the session management function object, where the first message is used to subscribe to the terminal device event.

The monitoring unit 22a is configured to monitor the subscribed event of the terminal device.

The transmitting unit 23a is configured: when the monitoring unit detects a tag event, to send a tag event notification to a function object that subscribes to the tag event, where the tag event notification includes at least one of the following information : ID of the tag corresponding to the tag event and tag event event correlation ID, where the event correlation ID is used to identify the relationship between the tag event and the function object that subscribes to the tag event.

Fig. 9b is a block diagram of another communication device according to an embodiment of the present invention. The communication device may be an object of the access and mobility control function described in the above communication system. In particular, the communication device 2000b may include a receiving unit 21b, a monitoring unit 22b, and a transmission unit 23b.

The receiving unit 21b is configured to receive a notification that is for monitoring a terminal device's availability event and that is transmitted by a session management function object.

The monitoring unit 22b is configured to monitor the availability event of the tag.

The transmitting unit 23b is configured to send a tag availability notification to the session management function object when the monitoring unit detects a tag availability event, in which the tag availability notification is used to monitor the tag availability event after downlink data notification failure.

Fig. 10 is a diagram of another communication device according to an embodiment of the present invention. The communication device may be the object of the session management function described in the above communication system. In particular, the communication device 3000 may include a transmission unit 31 and a reception unit 32 .

The transmission unit 31 is configured to direct the user plane function object to discover a service, where the service is the service corresponding to the subscribed event of the terminal, or is configured to send a service information request to the user plane function object. The receiving unit 32 is configured to receive a service discovery notification or service information sent by a user plane function object, in which the service discovery notification is used to indicate the occurrence of service data. The transmitting unit 31 is further configured to transmit, in response to the service discovery notification, a notification that is for monitoring a terminal event to the access and mobility control function object.

In the implementation, the receiving unit 32 is further configured to receive the first message transmitted by the control function object, where the first message is used to indicate a service, and the first message includes service description information for the service.

In another implementation, the first message is further used to subscribe to a tag event, the first message includes an event correlation ID and event type information for the tag event, the event correlation ID is used to identify a correlation relationship between the tag event and the function object that is being subscribed. per terminal event, and the event type information is used to identify the terminal event.

In yet another implementation, the transmission unit 31 is configured to instruct the user plane function object to discover a service when the user plane function object does not store access network tunnel information for transmitting service data.

In yet another implementation, the tag event includes a tag availability event after a downlink data notification failure. The receiving unit 32 is further configured to receive a tag availability notification or tag availability event notifications after downlink data notification failure, which is transmitted by the access and mobility control function entity; and transmitting the reachability notification of the terminal device after the failure of the downlink data transmission notification to the network exposure function object or the application function object.

Fig. 11 is a diagram of another communication device according to an embodiment of the present invention. The communication device may be a user plane function object described in the above communication system. In particular, the communication device 4000 may include a receiving unit 41, a detection unit 42, and a transmission unit 43.

The receiving unit 41 is configured to receive the first message or service information request sent by the session management function object, where the first message is used to indicate service discovery, and the service is the service corresponding to the subscribed event of the terminal. The discovery unit 42 is configured to discover a service based on the first message. The transmission unit 43 is configured to transmit a service discovery notification or service information to a session management function object, where the service discovery notification is used to indicate the occurrence of service data.

In an implementation, the discovery unit 42 is configured to discover a service based on the first message when the access network tunnel information for transmitting service data is not stored.

Fig. 12 is a hardware diagram of a communication device according to an embodiment of the present invention. The communications device includes a processor and may further include a receiver, a transmitter, and a memory. The receiver, transmitter, memory and processor are connected to each other via a bus.

Memory includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or read-only memory on a compact disk (compact disc read-only memory, CD-ROM). The memory is configured to store corresponding instructions and associated data.

The receiver is configured to receive data and/or signal and the transmitter is configured to transmit data and/or signal. The transmitter and receiver may be independent components or may be integral.

A processor may include one or more processors, such as one or more central processing units (CPUs). When the processor is a single CPU, the CPU may be single-core or multi-core.

The memory is configured to store program code and network device data.

The processor is configured to call the program code and data in the memory to perform the steps in the above method embodiments. For details, refer to the descriptions in the method embodiments, and details are not described here again.

It can be understood that Fig. 12 only shows a simplified structure of a communication device. During actual use, the communications device may further include other necessary components including, but not limited to, any number of transceivers, processors, controllers, memories, and the like, and all communications devices that may implement embodiments of the present invention, all should be within the protection scope of the present invention.

In an embodiment, the communication device may be the object of a control function in the above communication system. In FIG. 8, the associated function implemented by the receiving unit 13 may be implemented by the receiver, the associated function implemented by the transmitting unit 12 may be implemented by the transmitter, and the associated function implemented by the processing unit 11 may be implemented by one or more processors.

In particular, the processor is configured to determine the session management function object based on at least one of the data network name, the segment information, and the service identifier of the application function.

The transmitter is configured to send a first message to a session control function object, where the first message is used to subscribe to a tag event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the tag event.

In the implementation, the service description information is further used to determine the application function object that provides the service to the terminal.

In another implementation, the first message further includes an event correlation ID and tag event type information, the event correlation ID is used to identify the relationship between the tag event and the function object that subscribes to the tag event, and the event type information is used to identify the event. terminal device.

In yet another implementation, the transmitter is further configured to send a second message to an access and mobility control function object, where the second message is used to subscribe to a tag event, and the second message includes an event correlation identifier and event type information for the tag event, the event correlation identifier is used to identify the relationship between the tag event and the function object that subscribes to the tag event, and the event type information is used to identify the tag event.

In yet another implementation, the receiver is configured to receive a third message from an application function object, where the third message is used to subscribe to a tag event, and the third message includes service description information.

In yet another implementation, the third message further includes at least one of the following information: a tag identifier corresponding to the tag event, tag event type information, a data network name, segment information, and an application function service identifier. .

In yet another implementation, the receiver is further configured to receive a third message forwarded by the network exposure function object.

In yet another implementation, the transmitter is further configured to transmit at least one of service description information, an event correlation ID, a tag ID, a tag event type, a data network name, a segment information, and an application function service ID to the repository function object. unified data for storage.

In yet another implementation, the processor is further configured to obtain at least one of service description information, an event correlation ID, a tag ID, tag event type information, a data network name, segment information, and an application function service ID locally or from the unified data repository function object.

In yet another implementation, the receiver is further configured to receive a tag event notification from an access and mobility control function object or a session management function object. The transmitting unit 11 is further configured to transmit the terminal event notification to the application function object.

In yet another implementation, the tag event type includes a tag availability event after a downlink data notification failure.

In another embodiment, the communication device may be the object of an access and mobility control function in the aforementioned communication system. In FIG. 9a, the associated function implemented by the monitoring unit 22a may be implemented by one or more processors, the associated function implemented by the transmitting unit 23a may be implemented by the transmitter, and the associated function implemented by the receiving unit 21a may be implemented by the receiver.

In particular, the receiver is configured to receive the first message sent by the session management function object, where the first message is used to subscribe to the terminal device event.

The processor is configured to monitor the subscribed tag event.

The transmitter is configured to: when the monitoring unit detects a tag event, send a tag event notification to a function object that subscribes to the tag event, where the tag event notification includes at least one of the following information: identifier tag event corresponding to the tag event, and a tag event event correlation identifier, where the event correlation identifier is used to identify the relationship between the tag event and the function object that subscribes to the tag event.

In yet another embodiment, the communication device may be the object of an access and mobility control function in the aforementioned communication system. In FIG. 9b, the associated function implemented by the receiving unit 21b may be implemented by the receiver, the associated function implemented by the monitoring unit 22b may be implemented by one or more processors, and the associated function implemented by the transmitting unit 23b may be implemented by the transmitter.

In particular, the receiver is configured to receive a notification that is for monitoring a terminal's availability event and that is sent by a session management function object.

The processor is configured to monitor the tag's availability event.

The transmitter is configured to send a tag availability notification to the session control function object when the monitoring unit detects a tag availability event, in which the tag availability notification is used to monitor the tag availability event after downlink data notification failure.

In yet another embodiment, the communication device may be the object of a session management function in the aforementioned communication system. In FIG. 10, the corresponding function implemented by the transmitting unit 31 may be implemented by the transmitter, and the associated function implemented by the receiving unit 32 may be implemented by the receiver.

In particular, the transmitter is configured to instruct the user plane function object to discover a service, where the service is the service corresponding to the subscribed event of the terminal.

The receiver is configured to receive a service discovery notification transmitted by a user plane function object, where the service discovery notification is used to indicate the occurrence of service data.

The transmitter is further configured to send, in response to the service discovery notification, a notification that is for tracking a terminal event to the access and mobility control function object.

In the implementation, the receiver is further configured to receive the first message transmitted by the control function object, where the first message is used to indicate a service, and the first message includes service description information for the service.

In another implementation, the first message is further used to subscribe to a tag event, the first message includes an event correlation ID and event type information for the tag event, the event correlation ID is used to identify a correlation relationship between the tag event and the function object that is being subscribed. per terminal event, and the event type information is used to identify the terminal event.

In yet another implementation, the transmitter is configured to direct the user plane function object to discover a service when the user plane function object does not store access network tunnel information for transmitting service data.

In yet another implementation, the tag event includes a tag availability event after a downlink data notification failure. The receiver is further configured to receive a tag availability notification or a tag availability event notification after a downlink data notification failure, which is transmitted by the access and mobility control function entity; and transmitting the reachability notification of the terminal device after the failure of the downlink data transmission notification to the network exposure function object or the application function object.

In yet another embodiment, the communication device may be an object of a user plane function in the aforementioned communication system. In FIG. 11, the associated function implemented by the receiving unit 41 may be implemented by the receiver, the associated function implemented by the detection unit 42 may be implemented by one or more processors, and the associated function implemented by the transmitting unit 43 may be implemented by the transmitter.

In particular, the receiver is configured to receive a first message sent by a session control function object, where the first message is used to indicate to discover a service and the service is the service corresponding to the subscribed event of the terminal.

The processor is configured to discover a service based on the first message.

The transmitter is configured to send a service discovery notification to a session management function object, where the service discovery notification is used to indicate the occurrence of service data.

In an implementation, the processor is configured to discover a service based on the first message when the access network tunnel information for transmitting service data is not stored.

In yet another embodiment, the communication device may be the object of a session management function in the aforementioned communication system. In FIG. 15, the associated function implemented by the receiving unit 52 may be implemented by the receiver, the associated function implemented by the indicating unit 51 and the monitoring unit 53 may be implemented by one or more processors, and the associated function implemented by the transmitting unit 54 may be implemented by the transmitter.

In particular, the processor is configured to instruct the user plane function object to discover a service, where the service is a service corresponding to an event of a terminal to which the first application function object subscribes.

The receiver is configured to receive a service discovery notification sent by a user plane function object, where the service discovery notification is used to indicate that service data has been discovered.

The processor is further configured to monitor the tag event based on the service discovery notification when the tag is unavailable.

The transmitter is configured to: upon detection of a terminal device event, send a notification of the terminal device event to the network exposure function object or the first application function object.

Fig. 13 is a flowchart of another communication method according to an embodiment of the present invention. The method may include the following steps.

S901. The management function object determines the session management function object based on at least one of the data network name, the segment information, and the service identifier of the application function.

Specifically, that the management function object determines the session management function object based on at least one of the data network name, the segment information, and the application function service identifier may be: the management function object determines the session management function object based on the name network, based on the segment information, based on the service ID of the application function, based on the data network name and the segment information, based on the data network name and the service ID of the application function, based on the segment information and the service ID of the application function, or based on data network name, segment information, and application function service ID.

S902. The management function object passes the first message to the session management function object. The first message is used to subscribe to a terminal event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the terminal event.

The tag event includes a tag reachable event after downlink data notification failure or a tag reachable event.

Subscribing to a terminal event means that: when the service data is sent, the UE is not available; or when the service data cannot be sent, the UE availability event or the data availability event is monitored so that the AF retransmits the service data.

S903. The session control function object passes the second message to the user plane function object. The second message is used to instruct the user plane function object to discover the service. The service is the service corresponding to the subscribed event of the end device. Additionally, in another implementation, the second message may be a service information request and is used to direct the user plane function object to report the service information. In this case, the execution of S904 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

Alternatively, the SMF instructs the UPF to discover the service by sending the second message.

S904. Alternatively, when the received second message is used to direct the user plane function object to discover the service, the user plane function object discovers the service.

S905. The user plane function object sends a service discovery notification to the session control function object. The service discovery notification is used to indicate the occurrence of service data. The session management function object receives a service discovery notification. In another implementation, the service discovery notification may be service information, that is, service information in step S903. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S906. When the terminal device is not available, the session control function object monitors the event of the terminal device based on the service discovery notification.

Specifically, when the downlink data transmission failure notification sent by the access and mobility management function entity is received or the service data of the second application function entity is detected, it is determined that the terminal device is unavailable if the unreachability notification is sent from the access and mobility management function entity.

That the SMF monitors the tag event based on the service discovery notification means that the SMF monitors the tag event after the SMF receives the service discovery notification and when the UE is unavailable.

S907. When a tag event is detected, the session control function object passes a tag event notification to the application function object.

An exemplary method for monitoring a terminal event is to receive a terminal availability event notification or a terminal availability event notification after a downlink data failure, which is sent by an access and mobility control function entity; and monitoring a tag event when a tag availability event notification or a tag availability event notification after downlink data transmission failure, which is sent by the access and mobility control function entity, is received.

In particular, the tag event notification is passed to the NEF or the first application function object.

According to the communication method provided in this embodiment of the present invention, the session management function object instructs the user plane function object to discover a particular service; when the terminal device is not available, monitors the event of the terminal device based on the service discovery notification sent by the user plane function object; and sends a tag event notification when the tag event is detected. Thus, a terminal event can be subscribed and notified for a specific service in the 5G architecture.

The following describes in detail the embodiment shown in FIG. 13 with reference to specific examples.

Fig. 14a-1 and FIG. 14a-2 are flowcharts of yet another communication method according to an embodiment of the present invention. The method may include the following steps.

S1001. The UDM/PCF determines the target SMF based on the DNN/S-NSSAI/AF-service-ID. The DNN/S-NSSAI/AF-service-ID may be obtained from the UDR or may be stored locally.

S1002. The UDM/PCF sends the first message (eg Nsmf_EventExposure) to the target SMF. The first message includes service description information, event type information, and event correlation identifier (eg, NEF reference identifier), and may further include information such as NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

The SMF receives the first message.

Specifically, after the SMF receives the DDN failure availability event and the service description information, the SMF correlates the DDN failure availability event with the service description information. If they are sent together (sent in the same message), it means that they are correlated with each other. Alternatively, if the service description information is carried in the availability event subscription message after a DDN failure, this indicates that the two parameters are correlated with each other.

S1003. The SMF sends a service discovery message to the UPF in the session setup or change procedure N4. The service discovery message includes service description information.

In particular, when receiving a notification from the UPF that data corresponding to the service description information has been detected, the SMF may determine the event to which the data corresponds, trigger the event, and hence pass the event correlation identifier to the corresponding AMF. Additionally, in another implementation, the service discovery message may be a service information request used to direct a user plane function object to report service information. In this case, the execution of S1006 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

The UPF discovers the corresponding service based on the service discovery message, that is, it discovers the service corresponding to the service description information.

S1004. The AMF sends the UE unavailability information to the SMF.

The AMF may send UE unavailability information to the SMF when receiving service data sent by another AF upon detecting UE unavailability. Alternatively, the AMF sends UE unreachable information to the SMF in case of DDN data failure.

Alternatively, S1004 may be any step before S1007.

S1005. The AF transmits a downlink data packet to the terminal.

S1006. Alternatively, when the received service discovery message is used to instruct the user plane function object to discover the service, the UPF detects, according to the packet discovery rule, that the downlink data packet is a service corresponding to the subscribed event of the terminal.

When UPF does not store session access tunnel information, the user plane tunnel must be established and UPF sends a service discovery notification to the SMF. The service discovery notification is used to indicate that the occurrence of service data has been detected.

In particular, the service corresponding to the subscribed event of the terminal is the service corresponding to the service description information. The packet discovery rule includes service description information. For example, the service description information is an IP triplet, and the UPF detects a received downlink data packet based on the IP triplet. When a downlink data packet corresponding to an IP triplet is detected, it is determined that the occurrence of service data has been detected.

S1007. The SMF fires an event when the UE is not available.

In this embodiment, the SMF monitors the availability event of the terminal device.

For further procedure, refer to the embodiment shown in FIG. 7a-1 and FIG. 7a-2. The details are again not described here.

S1008. The end device establishes a connection to the network. For example, the terminal initiates a TAU request or service request to the network.

S1009. The AMF sends a UE availability event notification to the SMF.

In another implementation, the service discovery notification may be service information, that is, service information in S1003. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S1010. The SMF sends a tag event notification to the NEF if it determines that a UE availability event has been set locally. The tag event notification includes at least one of the following information: a tag device identifier and an event correlation identifier (eg, reference ID NEF).

S1011. The NEF sends a tag availability event notification (eg, Namf_EventExposure_Notify) to the AF based on the tag ID and/or the reference ID of the NEF.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal.

Fig. 14b-1 and FIG. 14b-2 are flowcharts of yet another communication method according to an embodiment of the present invention. The method may include the following steps.

S1101. The UDM/PCF determines the target SMF based on the DNN/S-NSSAI/AF-service-ID. The DNN/S-NSSAI/AF-service-ID may be obtained from the UDR or may be stored locally.

S1102. The UDM/PCF sends the first message to the target SMF.

S1103. The SMF sends a service discovery message to the UPF in the session setup or change procedure N4.

S1104. The AF transmits a downlink data packet to the terminal.

S1105. The UPF sends a Service Discovery Notification to the SMF.

S1106. The SMF sends a second AMF message.

Unlike the embodiment shown in FIG. 14a-1 and FIG. 14a-2, the second message here is a regular DDN message instead of an event subscription message. For the implementation of other steps, see the descriptions of the respective steps in FIG. 14a-1 and FIG. 14a-2. The details are again not described here. Additionally, in another implementation, the second message may be a service information request and is used to direct the user plane function object to report the service information. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S1107. The AMF sends a response message to the SMF to notify the SMF that the UE is not available.

Accordingly, after receiving the second message, if it is detected that the UE is unavailable, the AMF notifies the SMF that the UE is unavailable.

S1108. The SMF fires an event when the UE is not available.

S1109. The SMF sends a downlink data notification failure message to the UPF.

S1110. The AMF stores the first indication, where the first indication is used to indicate that the SMF has been notified of the unavailability of the UE.

The AMF stores the first indication to notify the SMF when the UE is available.

For the subsequent procedure, refer to the embodiment shown in FIG. 7a-1 and FIG. 7a-2. The details are again not described here.

S1111. The end device establishes a connection to the network.

S1112. The AMF sends a UE availability event notification to the SMF.

S1113. The SMF sends a tag event notification to the NEF if it determines that a UE availability event has been set locally.

S1114. The NEF sends a tag availability event notification to the AF based on the tag ID and/or the reference ID of the NEF.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal.

Fig. 14c-1 of FIG. 14c-3 are flowcharts of yet another communication method according to an embodiment of the present invention. The method applies to the roaming scenario. The method may include the following steps.

S1201. The UDM/PCF specifies to subscribe to a stub event from the SMF.

Specifically, the UDM/PCF determines the target H-SMF based on the DNN/S-NSSAI/AF-service-ID. The DNN/S-NSSAI/AF-service-ID may be obtained from the UDR or may be stored locally.

S1202a. The UDM/PCF sends the first message (eg, Nsmf_EventExposure) to the target H-SMF. The first message includes service description information, event type information, and event correlation identifier (eg, NEF reference identifier), and may further include information such as NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

The H-SMF receives the first message.

S1202b. The H-SMF forwards the first message to the V-SMF.

After the V-SMF receives the DDN failover availability event and the service description information, the V-SMF correlates the DDN failover availability event with the service description information. If they are sent together (sent in the same message), it means that they are correlated with each other. Alternatively, if the service description information is carried in the availability event subscription message after a DDN failure, this indicates that the two parameters are correlated with each other.

S1203. The V-SMF sends a service discovery message to the V-UPF in the session setup or change procedure N4. The service discovery message includes service description information.

Specifically, upon receiving notification from the V-UPF that data corresponding to the service description information has been detected, the V-SMF may determine the event to which the data corresponds, trigger the event, and hence may send an event correlation identifier to the corresponding AMF.

The V-UPF discovers the corresponding service based on the service discovery message, that is, discovers the service corresponding to the service description information.

Additionally, in another implementation, the second message may be a service information request and is used to direct the user plane function object to report the service information. In this case, the execution of S1205 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

For a subsequent procedure such as detecting by AMF whether the UE is reachable, refer to the embodiment shown in FIG. 7a-1 and FIG. 7a-2. The details are again not described here.

S1204. The AF transmits a downlink data packet to the terminal.

S1205. Alternatively, when the received second message is used to instruct the user plane function entity to discover a service, the V-UPF detects, according to the packet discovery rule, that the downlink data packet is a service corresponding to the subscribed terminal event.

When the V-UPF does not store session access tunnel information, a user plane tunnel must be established and the V-UPF sends a service discovery notification to the V-SMF. The service discovery notification is used to indicate that the occurrence of service data has been detected.

S1206. When the UE is unavailable, the V-SMF fires an availability event after a DDN failure.

In this embodiment, the V-SMF monitors the terminal event.

For the subsequent procedure such as detecting by AMF that the UE is available and notifying the V-SMF, refer to the embodiment shown in FIG. 7a-1 and FIG. 7a-2. The details are again not described here.

The end device initiates a connection to the network.

S1207. The AMF notifies the V-SMF of the first end event. The first terminal event notification is a UE availability event notification.

S1208a. The V-SMF sends a tag event notification to the NEF if it determines that the UE availability event has been set locally.

S1209. The NEF sends a tag availability event notification (eg, Namf_EventExposure_Notify) to the AF based on the tag ID and/or the reference ID of the NEF.

As an alternative step of S1208a and S1209, in S1208b, the V-SMF sends a tag availability event notification to the AF.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal.

Fig. 14d-1 and FIG. 14d-2 are flowcharts of yet another communication method according to an embodiment of the present invention. The method applies to the roaming scenario. The method may include the following steps.

S1301. The UDM/PCF decides to subscribe to a stub event from the SMF.

Specifically, the UDM/PCF determines the target H-SMF based on the DNN/S-NSSAI/AF-service-ID. The DNN/S-NSSAI/AF-service-ID may be obtained from the UDR or may be stored locally.

S1302. The UDM/PCF sends the first message (eg, Nsmf_EventExposure) to the target H-SMF. The first message includes service description information, event type information, and event correlation identifier (eg, NEF reference identifier), and may further include information such as NEF identifier. In this example, the event type is an endpoint availability event after a DDN failure.

The H-SMF receives the first message.

After the H-SMF receives the DDN failover availability event and the service description information, the H-SMF correlates the DDN failover availability event with the service description information. If they are sent together (sent in the same message), it means that they are correlated with each other. Alternatively, if the service description information is carried in the availability event subscription message after a DDN failure, this indicates that the two parameters are correlated with each other.

S1303. The H-SMF sends a service discovery message to the H-UPF in a session setup or change procedure N4. The service discovery message includes service description information.

In particular, when receiving from the H-UPF a discovery notification of data corresponding to the service description information, the H-SMF may determine the event to which the data corresponds, trigger the event, and therefore may send an event correlation identifier to the corresponding AMF.

The H-UPF discovers the corresponding service based on the service discovery message, that is, discovers the service corresponding to the service description information.

Additionally, in another implementation, the second message may be a service information request and is used to direct the user plane function object to report the service information. In this case, S1306 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S1304. The H-SMF receives the unreachable information of the UE.

The AMF may send UE availability information to the H-SMF when receiving service data sent by another AF and detecting UE unavailability.

Alternatively, S1304 may be any step before S1307.

S1305. The AF transmits a downlink data packet to the terminal.

S1306. Alternatively, when the received service discovery message is used to indicate to the user plane function entity to discover the service, the H-UPF detects, according to the packet discovery rule, that the downlink data packet is a service corresponding to the signed event of the terminal.

When the H-UPF does not store session access tunnel information, a user plane tunnel must be established and the H-UPF sends a service discovery notification to the H-SMF. The service discovery notification is used to indicate that the occurrence of service data has been detected.

S1307. When the UE is unavailable, the H-SMF activates an availability event after a DDN failure.

In this embodiment, the H-SMF monitors the tag event.

For the subsequent procedure such as detecting by AMF that the UE is available and notifying the H-SMF, refer to the embodiment shown in FIG. 7a-1 and FIG. 7a-2. The details are again not described here.

The end device initiates a connection to the network.

S1308. The AMF sends a terminal event notification to the V-SMF. The terminal event notification is a UE availability event notification.

S1309a. The V-SMF forwards the terminal event notification to the H-SMF.

S1309b. The H-SMF sends a tag event notification to the NEF if it determines that a UE availability event has been set locally.

S1310. The NEF sends a tag availability event notification (eg, Namf_EventExposure_Notify) to the AF based on the tag ID and/or the reference ID of the NEF.

After receiving the event notification of the terminal, the AF determines that the terminal is available and may retransmit the downlink data to the terminal.

Fig. 14e is a flowchart of yet another communication method according to an embodiment of the present invention. The method may include the following steps.

S1400. The V-SMF receives event information or indication information from the H-SMF. The indication information is used to direct the V-SMF to send a session release request N4 to the V-UPF when the V-SMF receives the session deactivation information sent by the AMF.

S1401a. The UE and the (R)AN perform a connection release procedure.

S1401b. The (R)AN sends a UE context release request to the AMF.

S1402. The AMF sends a UE context release command to the (R)AN.

S1403. The (R)AN and UE complete the connection release procedure.

S1404. The (R)AN sends a UE context release complete message to the AMF.

S1405. The AMF sends a session update session context message (session_update SM context PDU) to the V-SMF.

S1406. The V-SMF deletes the N4 V-UPF session according to the indication information and instructs the H-SMF to change the N4 A-UPF session. In the above embodiment, the V-SMF obtains the event monitoring information and can manage the session based on the event monitoring information.

In particular, the following steps are carried out:

S1406a. The V-SMF sends a session release request (N4 session release request) to the V-UPF.

S1406'a. The V-SMF sends a session update request PDU to the H-SMF.

S1406b. The V-UPF sends a session release response (N4) to the V-SMF.

S1406'b. The H-SMF sends a session update response PDU to the V-SMF.

S1407. The V-SMF sends a session update SM context ACK PDU to the AMF.

Fig. 14f is a flowchart of yet another communication method according to an embodiment of the present invention. The communication method may be applied to a multi-UPF scenario. For example, in this embodiment, the A-UPF manages an intermediate user plane function (I-UPF) entity. The method may include the following steps.

S1501a. The UE and the (R)AN perform a connection release procedure.

S1501b. The (R)AN sends a UE context release request to the AMF.

S1502. The AMF sends a UE context release command to the (R)AN.

S1503. The (R)AN and UE complete the connection release procedure.

S1504. The (R)AN sends a UE context release complete message to the AMF.

S1505. The AMF sends a session update session context message (session_update SM context PDU) to the SMF.

S1506. The SMF deletes the N4 I-UPF session based on the event monitoring information and changes the N4 A-UPF session. In the above embodiment, the SMF obtains the event monitoring information and can manage the session based on the event monitoring information. Session N4 is a session corresponding to the service description information.

In particular, the following steps are carried out:

S1506a. The SMF sends a session release request (N4 session release request) to the I-UPF.

S1506'a. The SMF sends a session modification request (N4 session modification request) to the A-UPF.

S1506b. The I-UPF sends a session release response (N4 session modification response) to the SMF.

S1506'b. The A-UPF sends a session modification response (N4 session modification response) to the SMF.

S1507. The SMF sends a session update SM context ACK PDU to the AMF.

Fig. 15 is a diagram of another communication device according to an embodiment of the present invention. Device 5000 may include:

an indication unit 51, configured to indicate to the user plane function object to discover a service, where the service is a service corresponding to an event of a terminal device subscribed to by the first application function object;

a receiving unit 52, configured to receive a service discovery notification transmitted by a user plane function object, where the service discovery notification is used to indicate that the service data has been detected;

a monitoring unit 53, configured to: when the terminal is unavailable, monitor an event of the terminal based on the service discovery notification; and

a transmitting unit 54, configured to: when a terminal event is detected, transmit the terminal event notification to the network exposure function object or the first application function object.

In a first possible implementation, the tag event includes a tag reachable event after a downlink data notification failure or a tag reachable event.

In a second possible implementation, when monitoring tag events, a tag availability event notification or a tag availability event notification after a downlink data send failure is received, which is sent by the access and mobility control function entity.

In a third possible implementation, the device further includes a determination unit configured to: when the downlink data transmission failure notification transmitted by the access and mobility control function object is received or service data of the second application function object is detected, determine that the terminal device is not available, if an unreachable notification is received, passed by the object to the access and mobility control function.

In a fourth possible implementation, the receiving unit 52 is further configured to receive a first message transmitted by a local session control function object, where the first message is used to indicate a service and indicate to subscribe to a tag event, and the first message includes service description information and an event correlation identifier and tag event type information, where an event correlation identifier is used to identify a relationship between the tag event and a function object that subscribes to the tag event, and the event type information is used to identify the tag event.

For the specific implementation of the indicating block 51, the receiving block 52, the monitoring block 53, and the transmitting block 54, reference is made to the embodiments shown in FIG. 13 - fig. 14f.

Fig. 16 is a flowchart of yet another communication method according to an embodiment of the present invention.

S1601. The management function object sends the first message for a terminal event to the AMF.

When or after the UE is registered with the network, the UDM/PCF decides to subscribe to an event from the AMF. The UDM/PCF decides to subscribe to an event from the AMF. The first message is used to subscribe to a terminal event, and the first message includes service description information and a DNN/S-NSSAI. The first message may further include an event type, an NEF identifier, and a reference NEF identifier.

S1602. After the AMF receives the first message, the AMF sends the second message to the SMF.

The second message is used to subscribe to a service discovery event, and the second message includes service description information. The second message may further include an event type, an NEF identifier, and a NEF reference identifier, or includes an event type, an AMF identifier, and an AMF reference identifier. The AMF Reference Identifier is generated by the AMF and used to correlate the corresponding event or event report.

In an implementation, the AMF determines whether the DNN/S-NSSAI session PDU that has been established or is being established is the same as the DNN/S-NSSAI included in the first message. When the DNN/S-NSSAI matches the DNN/S-NSSAI included in the first message, the AMF sends the second message to the SMF.

In yet another implementation, S1602 specifically includes: transmitting a subscription request to a local session control function object or a roaming session control function object; or

passing a session context update request to a local session management function object or a roaming session management function object, where the session context update request is used to subscribe to an end device event.

S1603. After receiving the second message, the SMF sends the third message to the UPF.

The third message is used to indicate to discover the service, and the service is the service corresponding to the subscribed event of the terminal.

In an implementation, S1603 includes: sending a third message to a user plane function object during or after session PDU deactivation, where the third message is used to indicate service discovery and the service is a service corresponding to a subscribed tag event. Specifically, the SMF subscribes to a service discovery event from the UPF with a session setup or change N4 procedure or a new N4 message.

Additionally, in another implementation, the third message may be a service information request and is used to direct the user plane function object to report the service information. In this case, S1604 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S1604. Alternatively, when the received third message is used to instruct the user plane function entity to discover the service, the UPF receives the third message; upon discovery of service data, UPF sends a service discovery notification to the SMF.

The service discovery notification is used to indicate the occurrence of service data. In another implementation, the service discovery notification may be service information, that is, service information in step S1603. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S1605. After receiving the service discovery notification, the SMF sends the service discovery notification to the AMF.

The service discovery notification contains a reference identifier that is used to index a particular event. The reference identifier is generated by AMF or NEF. If the reference ID is generated by the NEF, the NEF ID may optionally be included to eliminate the possibility of ambiguous identification of a particular event since different NEFs may generate the same reference ID. Possibly, a service discovery notification that is for tracking a terminal event may include event correlation information, such as a NEF reference ID. Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

S1606. After receiving the service discovery notification, the AMF determines whether the UE is available; and activates the aforementioned terminal event when the UE is not available.

S1607. Upon detecting that the UE is available, the AMF sends a terminal event notification to the capability exposure node or application function object.

According to the communication method provided in this embodiment of the present invention, the control function object may subscribe to a tag event from the AMF. The AMF fires a terminal event when it receives a service discovery notification and detects that the terminal is not available, and passes the terminal event notification to the capability exposure node or application function object when it detects that the terminal is available. Thus, a terminal event can be subscribed to a specific service in the 5G architecture.

The following describes the above communication method in full and in detail with reference to specific scenarios.

For the LBO scenario or the non-roaming scenario in FIG. 17-1 and FIG. 17-2 are flowcharts of yet another communication method according to an embodiment of the present invention.

S1701. When or after the UE is registered with the network, the UDM/PCF decides to subscribe to an event from the AMF.

S1702a. The UDM/PCF (AMF-PCF) sends a subscription request message (Namf_EventExposure) to the AMF, where the message includes the event type, NEF identifier, NEF reference identifier, DNN/S-NSSAI, and service description information.

S1702b. The AMF sends a Namf_EventExposure response message to the UDM/PCF.

S1703. The AMF determines to subscribe to an event from the SMF based on the DNN/S-NSSAI and determines whether the DNN/S-NSSAI session PDU that has been established or that has been established is the same as the DNN/DNN/S-NSSAI of the event.

S1704a. The AMF sends an Nsmf_EventExposure request to the SMF, where the request message includes the event type, service description, NEF identifier, and NEF reference identifier, or includes event type, service description, AMF identifier, and AMF reference identifier. The AMF reference identifier is generated by AMF and used to correlate the corresponding event or event report.

S1704b. The SMF sends the Nsmf_EventExposure response to the AMF.

S1705. The SMF subscribes to a service discovery event from the UPF with a session setup or change N4 procedure or a new N4 message.

In an implementation, the message may be a request for service information and is used to direct a user plane function object to report service information. In this case, S1706 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S1706. Alternatively, when the received message is used to instruct a user plane function object to discover a service, the UPF receives the data packet sent by the AF.

S1707. Upon determining that the data packet is the above specific service, the UPF sends a service discovery report to the SMF.

In another implementation, the service discovery report may be service information, that is, service information in step S1703. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S1708. The SMF passes Nsmf_EventExposureNotify to the AMF, where the message contains a reference identifier that is used to index the specific event. The reference identifier is generated by AMF or NEF. If the reference ID is generated by the NEF, the NEF ID may optionally be included to eliminate the possibility of ambiguous identification of a particular event since different NEFs may generate the same reference ID. Alternatively, a notification that is intended to track a terminal event may include event correlation information, such as an event correlation identifier (reference ID NEF). Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function object compares the service information.

S1709. AMF activates a specific event if the UE is not available.

S1710. The UE initiates a connection to the network.

S1711. The UE transitions to the available state and the AMF reports the UE availability event to the NEF.

S1712. The NEF further notifies the AF of the availability of the UE.

For the HR scenario in FIG. 18-1 and FIG. 18-2 are flowcharts of yet another communication method according to an embodiment of the present invention.

S1801. When or after the UE is registered with the network, the UDM/PCF decides to subscribe to an event from the AMF.

S1802a. The UDM/PCF (AMF-PCF) sends a Namf_EventExposure request message to the AMF, where the message includes the event type, NEF identifier, NEF reference identifier, DNN/S-NSSAI, and service description information.

S1802b. The AMF sends a Namf_EventExposure response message to the UDM/PCF.

S1803. The AMF determines to subscribe to an event from the H-SMF based on the DNN/S-NSSAI and determines whether the session DNN/S-NSSAI PDU that was established or that is configured is the same as the event DNN/S-NSSAI.

S1804a. The AMF sends an Nsmf_EventExposure request to the H-SMF, where the request message includes the event type, service description, NEF identifier, and NEF reference identifier, or includes the event type, service description, AMF identifier, and AMF reference identifier. The AMF Reference Identifier is generated by the AMF and used to correlate the corresponding event or event report.

Additionally, in another implementation, the request message may be a request for service information and is used to direct a user plane function object to report service information. In this case, S1806 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S1804b. The H-SMF sends the Nsmf_EventExposure response to the AMF. Alternatively, the AMF subscribes to an event from the H-SMF using the V-SMF. The AMF conveys the event subscription information to the V-SMF. In addition, the V-SMF sends the event subscription information to the H-SMF.

S1805. The H-SMF subscribes to a service discovery event from the H-UPF with a session setup or change N4 procedure or a new N4 message.

S1806. Alternatively, when the received subscription request message is used to instruct the user plane function entity to discover the service, the H-UPF receives the data packet sent by the AF.

S1807. When determining that the data packet is the above specific service, the H-UPF sends a service discovery report to the H-SMF. In another implementation, the service discovery report may be service information, that is, service information in step S1803. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S1808. The H-SMF sends Nsmf_EventExposureNotify to the AMF, where the message contains the reference identifier that is used to index the particular event. The reference identifier is generated by AMF or NEF. If the reference ID is generated by the NEF, the NEF ID may optionally be included to eliminate the possibility of ambiguous identification of a particular event since different NEFs may generate the same reference ID. Alternatively, the H-SMF sends an event notification to the V-SMF, so that the V-SMF sends an event notification to the AMF.

Alternatively, a notification that is intended to track a terminal event may include event correlation information, such as an event correlation identifier (reference ID NEF). Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

S1809. AMF activates a specific event if the UE is not available.

S1810. The UE initiates a connection to the network.

S1811. The UE transitions to the available state and the AMF reports the UE availability event to the NEF.

S1812. The NEF further notifies the AF of the availability of the UE.

For the LBO scenario or the non-roaming scenario in FIG. 19-1 and FIG. 19-2 are flowcharts of yet another communication method according to an embodiment of the present invention.

S1901. When or after the UE is registered with the network, the UDM/PCF decides to subscribe to an event from the AMF.

S1902a. The UDM/PCF (AMF-PCF) sends a Namf_EventExposure request message to the AMF, where the message includes the event type, NEF identifier, NEF reference identifier, DNN/S-NSSAI, and service description information.

S1902b. The AMF sends a Namf_EventExposure response message to the UDM/PCF.

S1903. The AMF determines to send the event to the SMF based on the DNN/S-NSSAI and determines whether the DNN/S-NSSAI session PDU that has been established or is being configured is the same as the event DNN/S-NSSAI.

S1904a. The AMF sends an Nsmf_PDUSession_UpdateSMContext request to the SMF, where the request message includes a service description, an NEF identifier, and a NEF reference identifier, or includes a service description, an AMF identifier, and an AMF reference identifier. The AMF Reference Identifier is generated by the AMF and used to correlate the corresponding event or event report.

S1904b. The SMF sends the Nsmf_PDUSession_UpdateSMContext response to the AMF.

S1905. The SMF sends the service discovery information to the UPF with a N4 session setup or change procedure or a new N4 message. Additionally, alternatively, the SMF sends service information to the UPF in the session PDU deactivation process, and the UPF is the UPF corresponding to the N3 interface. Furthermore, in another implementation, the subscription request message may be a service information request and is used to direct the user plane function object to report the service information. In this case, the execution of S1906 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S1906. Alternatively, when the received subscription request message is used to instruct the user plane function object to discover the service, the UPF receives the data packet sent by the AF.

S1907. Upon determining that the data packet is the above specific service, the UPF sends a service notification to the SMF using a DN message. In another implementation, the service notification may be service information, that is, service information in step S1903. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S1908a. The SMF sends a Namf_Communication_N1N2Message to the AMF, where the message contains a reference identifier that is used to index a specific event. The reference identifier is generated by AMF or NEF. If the reference ID is generated by the NEF, the NEF ID may be used, as an option, to eliminate the possibility of ambiguous identification of a particular event, since different NEFs may generate the same reference ID.

Alternatively, a notification that is intended to track a terminal event may include event correlation information, such as an event correlation identifier (reference ID NEF). Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

S1908b. The AMF sends a Namf_Communication_N1N2Message response to the SMF.

S1909. AMF activates a specific event if the UE is not available.

S1910. The UE initiates a connection to the network.

S1911. The UE transitions to the available state and the AMF reports the UE availability event to the NEF.

S1912. The NEF further notifies the AF of the availability of the UE.

For the HR scenario in FIG. 20-1 and FIG. 20-2 are flowcharts of yet another communication method according to an embodiment of the present invention.

S2001. When or after the UE is registered with the network, the UDM/PCF decides to subscribe to an event from the AMF.

S2002a. The UDM/PCF (AMF-PCF) sends a Namf_EventExposure request message to the AMF, where the message includes the event type, NEF identifier, NEF reference identifier, DNN/S-NSSAI, and service description information.

S2002b. The AMF sends a Namf_EventExposure response message to the UDM/PCF.

S2003. The AMF determines to send the event to the SMF based on the DNN/S-NSSAI and determines whether the DNN/S-NSSAI session PDU that has been established or is being configured is the same as the event DNN/S-NSSAI.

S2004a. The AMF sends an Nsmf_PDUSession_UpdateSMContext request to the V-SMF, where the request message includes a service description, an NEF identifier, and a NEF reference identifier, or includes a service description, an AMF identifier, and an AMF reference identifier. The AMF Reference Identifier is generated by the AMF and used to correlate the corresponding event or event report.

S2004b. The V-SMF sends the Nsmf_PDUSession_UpdateSMContext response to the AMF.

S2005. The V-SMF sends the service discovery information to the UPF using an N4 session setup or change procedure or a new N4 message. Additionally, alternatively, the V-SMF sends the service information to the UPF during the session PDU deactivation process. UPF is UPF terminating N3 interface or N9 interface. Additionally, in another implementation, the second message may be a service information request and is used to direct the user plane function object to report the service information. In this case, the execution of S2006 is not required. The service information may be at least one of a source IP address and a source port number of the downlink data packet, or may be index information, where the index information is used to index a particular event. The downlink data packet may be a discarded downlink data packet. Alternatively, if the downlink data notification fails, the session control function object sends a service information request to the user function object.

S2006. Alternatively, when the received subscription request message is used to instruct the user plane function entity to discover the service, the V-UPF receives the data packet sent by the AF.

S2007. In the absence of a downlink tunnel, the V-UPF determines that the data packet is the aforementioned specific service and sends a service notification to the V-SMF using a DN message. In another implementation, the service notification may be service information, that is, service information in step S2003. The service information is determined based on the downlink data packet, and specifically determined based on the packet header of the received downlink data packet. For example, when the downlink data packet is an IP data packet, the data packet header of the downlink data packet includes IP quintuple information; when the downlink data packet is an Ethernet data packet, the header of the downlink data packet includes a MAC address.

S2008a. The V-SMF sends a Namf_Communication_N1N2Message to the AMF, where the message contains a reference identifier that is used to index a specific event. The reference identifier is generated by AMF or NEF. If the reference ID is generated by the NEF, the NEF ID may be used, as an option, to eliminate the possibility of ambiguous identification of a particular event, since different NEFs may generate the same reference ID. Alternatively, a notification that is intended to track a terminal event may include event correlation information, such as an event correlation identifier (reference ID NEF). Event correlation information is used to determine event reporting information. Alternatively, the session management function entity transmits event correlation information to the mobility management entity based on the service description information and the service information. In other words, the session management function entity compares the service information with the service description information, and transmits the event correlation information to the mobility management entity when the service information matches the service description information.

S2008b. The AMF sends a Namf_Communication_N1N2Message response to the V-SMF.

S2009. AMF activates a specific event if the UE is not available.

S2010. The UE initiates a connection to the network.

S2011. The UE transitions to the available state and the AMF reports the UE availability event to the NEF.

S2012. The NEF further notifies the AF of the availability of the UE.

All or some of the above embodiments may be implemented in software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, the embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When computer program instructions are downloaded and executed on a computer, the procedure or functions according to embodiments of the present invention are generated in whole or in part. The computer may be a general purpose computer, a dedicated computer, a computer network, or other programmable devices. The computer instruction may be stored on a computer-readable storage medium or may be transmitted using a computer-readable storage medium. Computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center over a wired connection (such as coaxial cable, optical fiber, or digital subscriber line (DSL)) or wirelessly (for example, infrared, radio, microwave, etc.). A computer-readable storage medium can be any usable medium accessible to a computer, or a data storage device such as a server or data center that integrates one or more usable media. The media used can be magnetic media (such as a floppy disk, hard disk, or magnetic tape), optical media (such as a digital versatile disk (Digital Versatile Disk, DVD)), semiconductor media (such as a Solid State Dick, SSD) or the like.

One skilled in the art can understand that all or some of the processes of the methods in the embodiments may be implemented by a computer program instructing the appropriate equipment. The program may be stored on a computer-readable storage medium. When the program starts, the processes of the methods in the embodiments are executed. The aforementioned storage medium includes: any medium on which program code can be stored, such as Read-Only Memory (ROM), Random Access Memory (RAM), magnetic disk or optical disk.

Claims (83)

1. A communication method, comprising the steps of: determining a session management function object based on at least one of a data network name, segment information, and an application function service identifier; and transmitting a first message to a session management function object, wherein the first message is used to subscribe to an event of the terminal device and contains service description information, and the service description information is used to indicate a service corresponding to the event of the terminal device, wherein the first message further contains an event correlation identifier and terminal event type information, wherein the event correlation ID is used to identify event reporting information, the event type information is used to determine the terminal event, and the event reporting information is used to identify reported event information. 2. The method of claim 1, wherein the service description information is further used to determine an application function object providing a service to the terminal device. 3. The method of claim 1 or 2, further comprising: sending a second message to an access and mobility control function object, wherein the second message is used to subscribe to a tag event and contains an event correlation identifier and tag event type information. device, the event correlation ID is used to determine the event reporting information, and the event type information is used to identify the terminal event. 4. The method of claim 1 or 2, further comprising: sending a second message to an access and mobility control function object, wherein the second message is used to subscribe to a tag event and contains an event correlation identifier and tag event type information , wherein the event correlation identifier is used to identify the correlation relationship between the tag event and the function object subscribing to the tag event, and the event type information is used to identify the tag event. 5. The method according to any one of claims 1 to 4, further comprising the step of receiving service description information from the application function object. 6. The method of claim 5, further comprising the step of transmitting at least one of the service description information, event correlation identifier, or terminal event type to the unified data repository function object for storage. 7. The method according to any one of claims 1 to 6, further comprising the step of obtaining at least one of the service description information, event correlation identifier, or tag event type information locally or from the unified data repository function object. 8. A method according to any one of claims 5 to 7, further comprising the steps of: receiving a terminal event notification from an access and mobility control function object or a session management function object; and transmitting the terminal event notification to the application function object. 9. The method according to any one of claims 1 to 8, wherein the tag event type comprises a tag availability event after a downlink data notification failure. 10. A communication method, comprising the steps of: instructing a user plane function object to discover a service, the service being a service corresponding to the signed event of the terminal; receiving a service discovery notification sent by a user plane function object, the service discovery notification being used to indicate the occurrence of service data; and transmitting, in response to the service discovery notification, a notification for monitoring a terminal event to an access and mobility control function object or a control function object; receiving a first message transmitted by a control function object, wherein the first message is used to indicate a service and a subscription to an event of the terminal device, the first message contains service description information for the service and an event correlation identifier and event type information of the terminal device, and the event correlation identifier is used to determine event reporting information, event type information is used to identify the terminal event, and event reporting information is used to identify information about the reported event. 11. The method of claim 10, wherein the step of issuing an instruction to the user plane function object for service discovery comprises a sub-step of: instructing the user plane function object to discover the service when the user plane function object does not store access network tunnel information or downlink user plane tunnel information for transmitting service data; or instructing the user plane function object to perform service discovery notification when the user plane function object does not store access network tunnel information or downlink user plane tunnel information for transmitting service data. 12. A communication method, comprising the steps of: receiving a first message sent by a session management function object, wherein the first message is used to indicate the discovery of a service, and the service is a service corresponding to the subscribed event of the terminal, the first message contains service description information for the service, the service description information is used to indicate the service corresponding to the subscribed event terminal device, wherein the first message further contains an event correlation identifier and event type information of the subscribed terminal device, wherein the event correlation identifier is used to determine the event reporting information, the event type information is used to determine the event of the subscribed terminal device, and the event reporting information is used to identifying information about the reported event; detecting a service based on the first message; and transmitting a service discovery notification to the session management function object, the service discovery notification being used to indicate the occurrence of service data. 13. The method of claim 12, wherein the step of discovering a service based on the first message comprises a sub-step of: detecting a service based on the first message when the access network tunnel information for transmitting service data is not stored. 14. A communication method, comprising the steps of: a first message related to a terminal event and transmitted by a control function object is received, the first message is used to subscribe to the terminal device event and contains service description information and data network name/DNN/S-NSSAI one network segment selection support information, wherein the information the service description is used to indicate the service corresponding to the terminal event, wherein the first message further contains an event correlation identifier and subscribed terminal event type information, wherein the event correlation identifier is used to determine the event reporting information, the event type information is used to determine the subscribed event terminal device, and the event reporting information is used to identify information about the reported event; determining a session management function object according to the DNN/S-NSSAI; transmitting a second message to a session management function object, the second message being used to subscribe to a service discovery event and the second message containing service description information; receiving a service discovery notification from a session management function object; activating a tag event when the tag is unavailable; and transmitting a tag availability notification to the capability exposure node or application function object upon detecting that the tag is available. 15. The method of claim 14, wherein the step of sending the second message to the session management function object comprises the sub-step of transmitting a second message to the session control function entity when the session DNN/S-NSSAI matches the DNN/S-NSSAI contained in the first message. 16. The method of claim 14 or 15, wherein the step of sending the second message to the session management function object comprises the sub-step of transmitting a subscription request to a local session management function object or a roaming session management function object, or transmitting a session context update request to a local session management function object or a roaming session management function object, wherein the session context update request is used to subscribe to the terminal device event. 17. A communication method, comprising the steps of: receiving a second message for a terminal event from a mobility management function (AMF) entity; transmitting a third message to a User Plane Function (UPF) object, wherein the third message is used to instruct discovery of a service, said service being the service corresponding to the subscribed event of the terminal, wherein the third message contains service description information for the service, the service description information is used for indicating the service corresponding to the terminal event, wherein the third message further comprises an event correlation identifier and terminal event type information, wherein the event correlation identifier is used to determine the event reporting information, the event type information is used to determine the terminal event, and the reporting information event is used to identify information about the reported event; receiving a service discovery notification from a user plane function entity, the service discovery notification being used to indicate the occurrence of service data; and transmitting a service discovery notification to the mobility management function entity. 18. The method of claim 17, wherein the step of receiving a second message for a terminal event from a mobility management function entity comprises a sub-step of receiving a session context update request from a mobility management function entity, wherein the session context update request is used to subscribe to a terminal event. 19. The method of claim 17, wherein the step of sending the third message to the user plane function object comprises the sub-step of transmitting a third message to the user plane function object during or after session PDU deactivation, the third message being used to instruct service discovery, the service being the service corresponding to the subscribed event of the terminal. 20. A communication method, comprising the steps of: a first message is received from the control function object, the first message is used to subscribe to the terminal device event and contains service description information, and the service description information is used to indicate a service corresponding to the terminal device event, the first message further contains an event correlation identifier and information about the event type of the subscribed terminal, wherein the event correlation ID is used to identify event reporting information, the event type information is used to determine the event of the subscribed terminal, and the event reporting information is used to identify information about the reported event; receiving service information from a UPF user function entity, wherein the service information is determined based on the downlink data packet; and transmitting the event correlation information to the mobility management entity or the capability exposure entity based on at least the service information, the event correlation information being used to determine the event reporting information. 21. The method of claim 20, further comprising, before receiving service information from the user function object, transmitting the service information request to the user function object. 22. The method of claim 21, wherein the step of transmitting a service information request to the user function object comprises a sub-step of: transmitting a service information request to the user function entity when the unavailability information of the UE is received. 23. The method of claim 21, wherein the step of transmitting a service information request to the user function object comprises a sub-step of: transmitting a service information request to the user function object in case of downlink data notification failure. 24. The method of claim 20, wherein the step of transmitting the event correlation information to the mobility management entity or the capability exposure entity when the event correlation information is used to determine the event reporting information comprises the sub-step of transmitting the event correlation information to the mobility management entity or the capability exposure entity based on the service description information and the service information, the event correlation information being used to determine the event reporting information. 25. A communications device comprising a processor, wherein the processor is configured to communicate with the memory and read and execute instructions from the memory to implement the method of any one of claims 1-9. 26. The device according to claim 25, further comprising memory. 27. A communication device comprising a processor, wherein the processor is configured to communicate with the memory and read and execute instructions from the memory to implement the method of claim 10 or 11. 28. The device according to claim 27, further comprising memory. 29. A communication device comprising a processor, wherein the processor is configured to communicate with the memory and read and execute instructions from the memory to implement the method of claim 12 or 13. 30. The device according to claim 29, further comprising memory. 31. A communications device comprising a processor, the processor being capable of communicating with a memory and reading and executing instructions from the memory to implement the method of any one of claims 14-16. 32. The device according to claim 31, further comprising memory. 33. A communications device comprising a processor, the processor being capable of communicating with a memory and reading and executing instructions from the memory to implement the method of any one of claims 17-19. 34. The device according to claim 33, further comprising memory. 35. A communication device comprising a processor, wherein the processor is configured to communicate with the memory and read and execute instructions from the memory to implement the method according to any one of claims 20-24. 36. The device according to claim 35, further comprising memory. 37. A computer-readable storage medium storing instructions causing, when executed by a computer, the computer to execute a method according to any one of claims 1-9. 38. A communication system comprising a communication device according to claim 35 or 36.

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