WO2023051772A1

WO2023051772A1 - Method and apparatus for event reporting

Info

Publication number: WO2023051772A1
Application number: PCT/CN2022/123172
Authority: WO
Inventors: Jingrui TAO; Bo Zhang; Yunjie Lu
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2021-09-30
Filing date: 2022-09-30
Publication date: 2023-04-06

Abstract

Embodiments of the present disclosure provide method and apparatus for event reporting. A method performed by an NEF comprises receiving a first monitoring request from an application node. The method further comprises sending a second monitoring request to a UDM. The first monitoring request and/or the second monitoring request comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.

Description

METHOD AND APPARATUS FOR EVENT REPORTING

TECHNICAL FIELD

The non-limiting and exemplary embodiments of the present disclosure generally relate to the technical field of communications, and specifically to methods and apparatuses for event reporting.

BACKGROUND

This section introduces aspects that may facilitate a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.

Monitoring Event

There is a need for monitoring events feature in some communication networks. The monitoring events feature is intended for monitoring of specific event (s) in the communication network and making such monitoring events information available via a network node such as exposure function node. It is comprised of means that allow an identification of a network element suitable for configuring the specific events, the event detection, and the event reporting to authorized users, e.g. for use by applications or logging, etc. If such an event is detected, the network might be configured to perform special actions, e.g. limit the UE (user equipment) access.

Service Capability Exposure Function (SCEF) in 4G (fourth generation) network or Network Exposure Function (NEF) in 5G (fifth generation) network is a network function for service capability exposure within 3rd Generation Partnership Project (3GPP) architecture. SCEF or NEF can provide a means to securely expose the services and capabilities provided by 3GPP network interfaces through Application Programming Interfaces (APIs) to AS/SCS (Application Servers/Services Capability Server) or AF (Application Function) .

Clause 5.6 of 3GPP TS 23.682 V17.0.0, the disclosure of which is incorporated by reference herein in its entirety, defines various monitoring procedures, e.g., Monitoring Event configuration and deletion via home subscriber server (HSS) , Monitoring Events configuration and deletion directly at the MME/SGSN (Mobile Management Entity/Serving GPRS (General Packet Radio Service) Support Node) , Reporting of Monitoring Events from the HSS or the MME/SGSN, Monitoring events configuration and reporting via PCRF, Reporting of Monitoring Events from the PCRF, etc.

Clause 4.15.3 of 3GPP TS 23.502 V17.1.0, the disclosure of which is incorporated by reference herein in its entirety, defines event exposure using NEF. It described various information flows, such as AMF (Access and mobility Function) service operations information flow, UDM (Unified Data Management) service operations information flow, NEF service operations information flow, etc.

For example, as described in clause 4.5.6 of 3GPP TS 23.682 V17.0.0, the disclosure of which is incorporated by reference herein in its entirety, configuration and reporting of the following monitoring events may be supported in the network:

- Monitoring the association of the UE and UICC (universal integrated circuit card) and/or new IMSI-IMEI-SV (International Mobile Subscriber Identity-International Mobile Equipment Identity-software version) association;

- UE reachability;

- Location of the UE, and change in location of the UE;

- Loss of connectivity;

- Communication failure;

- Roaming status (i.e. Roaming or No Roaming) of the UE, and change in roaming status of the UE;

- Number of UEs present in a geographical area;

- Availability after DDN (Digital Data Network) failure; and

- PDN (Packet Data Network) Connectivity Status.

The set of capabilities required for monitoring may be accessible via different interfaces/nodes. Selection of interface (s) to configure/report the event is dependent on the type of the event, operator configuration, required frequency of event reporting, application provided parameters in monitoring event request, etc.

Support for Monitoring Events can be offered either via MME/HSS, MME/SGSN (as described in clause 4.5.6.2 of 3GPP TS 23.682 V17.0.0) or via PCRF (Policy and Charging Rules Function) (as described in clause 4.5.6.3 of 3GPP TS 23.682 V17.0.0) . Based on operator policies, it shall be possible to configure Monitoring Events such that some Monitoring Event follows procedures in clause 4.5.6.2 of 3GPP TS 23.682 V17.0.0 while another Monitoring Event follows procedures in clause 4.5.6.3 of 3GPP TS 23.682 V17.0.0. Service Capability Exposure Function (SCEF) shall not enable a given Monitoring Event for the same UE via both HSS/MME/SGSN, and PCRF.

Extended idle mode DRX

As described in clause 4.5.13 of 3GPP TS 23.682 V17.0.0, the UE and the network may negotiate over non-access stratum (NAS) signaling the use of extended idle mode DRX (Discontinuous Reception) for reducing its power consumption, while being available for mobile terminating data and/or network originated procedures within a certain delay dependent on the eDRX (Extended Discontinous Reception) cycle value. The negotiation of the eDRX parameters for WB-E-UTRA (Wideband Evolved Universal Terrestrial Radio Access) and LTE-M (Long Term Evolution category M1) is supported over any RAT (Radio Access Technology) (including NR (New Radio) ) .

Extended DRX in CM (Connection Management) -IDLE is supported for E-UTRA connected to 5GC (5G core network) . Extended DRX in CM-CONNECTED with RRC (Radio Resource Control) -Inactive mode is supported for WB-E-UTRA and LTE-M connected to 5GC.

Applications that want to use extended idle mode DRX need to consider specific handling of mobile terminating services or data transfers, and in particular they need to consider the delay tolerance of mobile terminated data. A network side application may send mobile terminated data, an SMS (Short Message Service) , or a device trigger, and needs to be aware that extended idle mode DRX may be in place. A UE should request for extended idle mode DRX only when all expected mobile terminating communication is tolerant to delay.

In order to negotiate the use of extended idle mode DRX, the UE requests extended idle mode DRX parameters during attach procedure and RAU (Routing Area Update) /TAU (Tracking Area Update) procedure. The SGSN/MME may reject or accept the UE request for enabling extended idle mode DRX. If the SGSN/MME accepts the extended idle mode DRX, the SGSN/MME based on operator policies and, if available, the extended idle mode DRX cycle length value in the subscription data from the HSS, may also provide different values of the extended idle mode DRX parameters than what was requested by the UE. If the SGSN/MME accepts the use of extended idle mode DRX, the UE applies extended idle mode DRX based on the received extended idle mode DRX parameters. If the UE does not receive extended idle mode DRX parameters in the relevant accept message because the SGSN/MME rejected its request or because the request was received by SGSN/MME not supporting extended idle mode DRX, the UE shall apply its regular discontinuous reception as defined in clause 5.13 of 3GPP TS 23.401 V17.2.0, the disclosure of which is incorporated by reference herein in its entirety.

The extended idle mode DRX cycle length requested by UE takes into account requirements of applications running on the UE. Subscription based determination of eDRX cycle length can be used in those rare scenarios when applications on UE cannot be modified to request appropriate extended idle mode DRX cycle length. The network accepting extended DRX while providing an extended idle mode DRX cycle length value longer than the one requested by the UE, can adversely impact reachability requirements of applications running on the UE.

The specific negotiation procedure handling is described in 3GPP TS 23.060 V16.0.0 and 3GPP TS 23.401 V17.2.0.

If a UE requests via NAS both to enable PSM (Power Saving Mode) (requesting an active time and possibly a periodic TAU timer) and extended idle mode DRX (with a specific extended idle mode DRX cycle value) , it is up to the SGSN/MME to decide whether to:

1. Enable only PSM, i.e. not accept the request for extended idle mode DRX.

2. Enable only extended idle mode DRX, i.e. not accept the request for an active time.

3. Enable both PSM (i.e. provide an active time) and extended idle mode DRX (i.e. provide an extended idle mode DRX parameters) .

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Via NEF, an AF can subscribe to UE reachability event and get notified when the UE becomes reachable. Additionally, the AF may provide reporting options, e.g. max number of reports expected and max duration.

The UE reachability may be influenced by certain aspects, e.g. periodically registration timer, or the extended DRX cycle for Internet of Things (IoT) devices. These parameters may be controlled by operator policies as well as AF requests, and the UDM will do aggregation and usually set the parameter as the minimal value (allowed by local policy) to fulfil the requirements from all AFs.

But for certain AFs, their use cases may require less frequent event reports intentionally. E. g. an AF may push upgrade SW (software) to the device when the UE becomes reachable and the SW upgrade cycle could be daily or weekly. For the AFs, too frequent event report is not desired, and is harmful from system load and network traffic as well as the AF load.

Existing 3GPP specification does not define any mechanism to control the continuous UE reachability (SMS/Data) event report frequency from network.

For WB-E-UTRAN, the extended idle mode DRX value range will consist of values starting from 5.12s (i.e. 5.12s, 10.24s, 20.48s, etc. ) up to a maximum of 2621.44s (almost 44 minutes) . For narrow band internet of things (NB-IoT) , the extended idle mode DRX value range will start from 20.48s (i.e. 20.48s, 40.96s, 81.92, etc. ) up to a maximum of 10485.76s (almost 3 hours) (see 3GPP TS 36.304 V16.4.0) .

If AMF/MME is requested to monitor UE reachability for data and the eDRX enabled UE is about to become reachable for paging, the MME sends a Monitoring Report message to the address that was indicated in a related Monitoring Request as described in 3GPP TS 23.682 V17.0.0.

When the eDRX cycle length is small, e.g. 20.48 seconds, the AMF/MME should send UE data reachable event reports to AF/AS via NEF/SCEF with very high frequency. It will be a big traffic load for MME/SGSN to send so many reports with such high frequency. In addition, it may not be expected by SCS/AS/AF as well.

Seeking for the possibility of controlling UE reachability report frequency for UE using idle mode eDRX may be expected.

To overcome or mitigate at least one of the above mentioned problems or other problems, an improved event reporting solution may be desirable. For example, as an improvement, it should be possible to allow a network node (such as AF/AS/SCS, etc. ) to throttle the too frequent event reporting.

In a first aspect of the disclosure, there is provided a method performed by an NEF. The method comprises receiving a first monitoring request from an application node. The method further comprises sending a second monitoring request to a UDM. The first monitoring request and/or the second monitoring request comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.

In an embodiment, the first monitoring request comprises at least one of a Monitoring Request message, or an Nnef_EventExposure_Subscribe request.

In an embodiment, the second monitoring request comprises at least one of a Monitoring Request message, an Nudm_EventExposure_Subscribe request, an Namf_EventExposure_Subscribe request, or an Nsmf_EventExposure_Subscribe request.

In an embodiment, the application node comprises at least one of Application Servers (AS) , Services Capability Server (SCS) , or Application Function (AF) .

In an embodiment, the method further comprises receiving a first event notification message comprising an event report related to the first monitoring request from a network node.

In an embodiment, the method further comprises sending a second event notification message comprising the event report related to the first monitoring request to the application node.

In an embodiment, the first event notification message is sent to the NEF based on the event reporting interval.

In an embodiment, the second event notification message is sent to the application node based on the event reporting interval.

In an embodiment, the network node comprises at least one of HSS, UDM, MME, SGSN, AMF, or SMF.

In an embodiment, the first event notification message comprises at least one of a Monitoring Indication message, a Monitoring Response message, an Nudm_EventExposure_Notify message, an Namf_EventExposure_Notify message, or an Nsmf_EventExposure_Notify message.

In an embodiment, the second event notification message comprises at least one of a Monitoring Indication message, a Monitoring Response message, or an Nnef_EventExposure_Notify message.

In a second aspect of the disclosure, there is provided a method performed by an application node. The method comprises sending a first monitoring request to an NEF. The method further comprises receiving a second event notification message from the NEF. The second event notification message is sent to the application node based on event reporting interval. The event reporting interval indicates a minimal interval to report an event. The first monitoring request is used for monitoring user equipment (UE) reachability.

In an embodiment, the first monitoring request comprises the information indicating the event reporting interval.

In a third aspect of the disclosure, there is provided a method performed by a UDM. The method comprises receiving a second monitoring request from an NEF. The second monitoring request is used for monitoring user equipment (UE) reachability and comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The method further comprises sending a third monitoring request to an AMF. The third monitoring request comprises the information indicating the event reporting interval.

In an embodiment, the method further comprises detecting a monitoring event related to the second monitoring request.

In an embodiment, the method further comprises sending a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

In an embodiment, the third monitoring request comprises at least one of a Monitoring Request message, an Nudm_EventExposure_Subscribe request, an Namf_EventExposure_Subscribe request, or an Nsmf_EventExposure_Subscribe request.

In an embodiment, the method further comprises sending monitoring event configuration information to a third network node. The monitoring event configuration information comprises the information indicating the event reporting interval.

In an embodiment, the method further comprises the monitoring event configuration information is sent during at least one of a procedure of UE moving from fifth generation system (5GS) to Evolved Packet System (EPS) , a procedure of UE moving from EPS to 5GS, a registration procedure with a change of Access and mobility Function (AMF) , a procedure with SMF change, or an Inter next generation radio access network (NG-RAN) node N2 based handover procedure with a change of Access and mobility Function (AMF) .

In an embodiment, the method further comprises the monitoring event configuration information further comprises information indicating remain time of the event reporting interval.

In a fourth aspect of the disclosure, there is provided a method performed by an Access and mobility Function, AMF. The method comprises receiving a third monitoring request for monitoring user equipment (UE) reachability from a UDM. The third monitoring request comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The method further comprises detecting a monitoring event related to the third monitoring request. The method further comprises sending a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

In an embodiment, the method further comprises sending monitoring event configuration information to a third network node. . The monitoring event configuration information comprises the information indicating the event reporting interval.

In a fifth aspect of the disclosure, there is provided a method performed by a third network node, comprising. The method comprises receiving monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and information indicating remain time of the event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event. The method further comprises detecting a monitoring event related to the monitoring event configuration information. The method further comprises sending an event notification message comprising the monitoring event to an NEF based on the event reporting interval and the remain time of the event reporting interval.

In an embodiment, the network node comprises at least one of MME, SGSN, AMF, or SMF.

In an embodiment, the third network node comprises at least one of MME, SGSN, AMF, or SMF..

In an embodiment, the monitoring event configuration information is received or sent during at least one of a procedure of UE moving from fifth generation system (5GS) to Evolved Packet System (EPS) , a procedure of UE moving from EPS to 5GS, a registration procedure with a change of Access and mobility Function (AMF) , a procedure with SMF change, or an Inter next generation radio access network (NG-RAN) node N2 based handover procedure with a change of Access and mobility Function (AMF) .

In a sixth aspect of the disclosure, there is provided an NEF. The NEF comprises a processor and a memory coupled to the processor. Said memory contains instructions executable by said processor. Said NEF is operative to receive a first monitoring request from an application node. Said NEF is further operative to send a second monitoring request to a UDM. The first monitoring request and/or the second monitoring request comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.

In a seventh aspect of the disclosure, there is provided an application node. The application node comprises a processor and a memory coupled to the processor. Said memory contains instructions executable by said processor. Said application node is operative to send a first monitoring request to an NEF. Said application node is further operative to receive a second event notification message from the NEF. The second event notification message is sent to the application node based on event reporting interval. The event reporting interval indicates a minimal interval to report an event. The first monitoring request is used for monitoring user equipment (UE) reachability.

In an eighth aspect of the disclosure, there is provided a UDM. The UDM comprises a processor and a memory coupled to the processor. Said memory contains instructions executable by said processor. Said UDM is operative to receive a second monitoring request from an NEF. The second monitoring request is used for monitoring user equipment (UE) reachability and comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. Said UDM is further operative to send a third monitoring request to an AMF. The third monitoring request comprises the information indicating the event reporting interval.

In a ninth aspect of the disclosure, there is provided an AMF. The AMF comprises a processor and a memory coupled to the processor. Said memory contains instructions executable by said processor. Said AMF is operative to receive a third monitoring request for monitoring user equipment (UE) reachability from a Unified Data Management, UDM. The third monitoring request comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. Said AMF is further operative to detect a monitoring event related to the third monitoring request. Said AMF is further operative to send a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

In a tenth aspect of the disclosure, there is provided a third network node. The third network node comprises a processor and a memory coupled to the processor. Said memory contains instructions executable by said processor. Said third network node is operative to receive monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and information indicating remain time of the event reporting interval. The event reporting interval indicates a minimal interval to report an event. Said third network node is further operative to detect a monitoring event related to the monitoring event configuration information. Said third network node is further operative to send an event notification message comprising the monitoring event to an NEF based on the event reporting interval and the remain time of the event reporting interval.

In an eleventh aspect of the disclosure, there is provided an NEF. The NEF comprises a first receiving module and a first sending module. The first receiving module may be configured to receive a first monitoring request from an application node. The first sending module may be configured to send a second monitoring request to a UDM. The event reporting interval indicates a minimal interval to report an event. The first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.

In an embodiment, the NEF further comprises a second receiving module configured to receive a first event notification message comprising an event report related to the first monitoring request from a network node.

In an embodiment, the NEF further comprises a second sending module configured to send a second event notification message comprising the event report related to the first monitoring request to the application node.

In a twelfth aspect of the disclosure, there is provided an application node. The application node comprises a sending module and a receiving module. The sending module may be configured to send a first monitoring request to an NEF. The receiving module may be configured to receive a second event notification message from the NEF. The second event notification message is sent to the application node based on event reporting interval. The event reporting interval indicates a minimal interval to report an event. The first monitoring request is used for monitoring user equipment (UE) reachability.

In a thirteenth aspect of the disclosure, there is provided a UDM. The UDM comprises a receiving module. The receiving module may be configured to receive a second monitoring request from an NEF. The second monitoring request is used for monitoring user equipment (UE) reachability and comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The UDM further comprises a third sending module configured to send a third monitoring request to an AMF. The third monitoring request comprises the information indicating the event reporting interval.

In an embodiment, the UDM further comprises a detecting module configured to detect a monitoring event related to the second monitoring request.

In an embodiment, the UDM further comprises a first sending module configured to send a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

In an embodiment, the UDM further comprises a second sending module configured to send monitoring event configuration information to a third network node. The monitoring event configuration information comprises the information indicating the event reporting interval.

In a fourteenth aspect of the disclosure, there is provided an AMF. The AMF comprises a receiving module. The receiving module may be configured to receive a third monitoring request for monitoring user equipment (UE) reachability from a UDM. The third monitoring request comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The AMF further comprises a detecting module configured to detect a monitoring event related to the third monitoring request. The AMF further comprises a first sending module configured to send a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

In an embodiment, the second network node further comprises a second sending module configured to send monitoring event configuration information to a third network node. The monitoring event configuration information comprises the information indicating the event reporting interval.

In a fifteenth aspect of the disclosure, there is provided a third network node. The third network node comprises a receiving module. The receiving module may be configured to receive monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and information indicating remain time of the event reporting interval. The event reporting interval indicates a minimal interval to report an event. The third network node further comprises a detecting module configured to detect a monitoring event related to the monitoring event configuration information. The third network node further comprises a first sending module configured to send an event notification message comprising the monitoring event to an NEF based on the event reporting interval and the remain time of the event reporting interval.

In a sixteenth aspect of the disclosure, there is provided a computer-readable storage medium storing instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of the first, second, third, fourth and fifth aspects.

In a seventeenth aspect of the disclosure, there is provided a computer program product comprising instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of the first, second, third, fourth and fifth aspects.

Embodiments herein offer many advantages, of which a non-exhaustive list of examples follows. Some embodiments herein provide a mechanism for SCS/AS/AF to influence the event reporting frequency. Some embodiments herein ensure a minimum time gap between consecutive monitoring event report initiated by the network. Some embodiments herein help reducing peak load situations when a UE event report condition is met many times within a short time in an operator network. Some embodiments herein can be used for monitoring event reports for MTC/CIoT (Cellular IoT) UEs where the applications are tolerant to service latency. Some embodiments herein can enable SCS/AS/AF to throttle the reporting of UE reachability event. Some embodiments herein can avoid unnecessary event report notifications to SCS/AS/AF and decrease traffic load and network node load. The embodiments herein are not limited to the features and advantages mentioned above. A person skilled in the art will recognize additional features and advantages upon reading the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and benefits of various embodiments of the present disclosure will become more fully apparent, by way of example, from the following detailed description with reference to the accompanying drawings, in which like reference numerals or letters are used to designate like or equivalent elements. The drawings are illustrated for facilitating better understanding of the embodiments of the disclosure and not necessarily drawn to scale, in which:

FIG. 1a schematically shows system architecture in a 4G network according to an embodiment of the present disclosure;

FIG. 1b schematically shows a high level architecture in the fifth generation network according to an embodiment of the present disclosure;

FIG. 1c schematically shows a system architecture for service exposure for EPC-5GC interworking according to an embodiment of the present disclosure;

FIG. 2 shows a flowchart of a method according to an embodiment of the present disclosure;

FIG. 3a shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 3b shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 4a shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 4b shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 5 shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 6 shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 7 shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 8a shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 8b shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 9 shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 10 shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 11a shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 11b shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 12 shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 13 shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 14a shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 14b shows a flowchart of a method according to another embodiment of the present disclosure;

FIG. 15 shows a flowchart for configuring the maximum UE reachability event report frequency initiated by AS/SCS through SCEF in 4G EPC according to an embodiment of the present disclosure;

FIG. 16 shows a flowchart for controlling the maximum event report frequency in 5GC and AF according to an embodiment of the present disclosure;

FIG. 17 is a block diagram showing an apparatus suitable for practicing some embodiments of the disclosure;

FIG. 18 is a block diagram showing an exposure function node according to an embodiment of the disclosure;

FIG. 19 is a block diagram showing an application node according to an embodiment of the disclosure;

FIG. 20 is a block diagram showing a first network node according to an embodiment of the disclosure;

FIG. 21 is a block diagram showing a second network node according to an embodiment of the disclosure; and

FIG. 22 is a block diagram showing a third network node according to an embodiment of the disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure are described in detail with reference to the accompanying drawings. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the present disclosure. Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present disclosure should be or are in any single embodiment of the disclosure. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Furthermore, the described features, advantages, and characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the disclosure may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the disclosure.

As used herein, the term “network” refers to a network following any suitable communication standards such as new radio (NR) , long term evolution (LTE) , LTE-Advanced, wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , Code Division Multiple Access (CDMA) , Time Division Multiple Address (TDMA) , Frequency Division Multiple Access (FDMA) , Orthogonal Frequency-Division Multiple Access (OFDMA) , Single carrier frequency division multiple access (SC-FDMA) and other wireless networks. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA) , etc. UTRA includes WCDMA and other variants of CDMA. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA network may implement a radio technology such as Evolved UTRA (E-UTRA) , Ultra Mobile Broadband (UMB) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDMA, Ad-hoc network, wireless sensor network, etc. In the following description, the terms “network” and “system” can be used interchangeably. Furthermore, the communications between two devices in the network may be performed according to any suitable communication protocols, including, but not limited to, the communication protocols as defined by a standard organization such as 3GPP. For example, the communication protocols as may comprise the first generation (1G) , 2G, 3G, 4G, 4.5G, 5G communication protocols, and/or any other protocols either currently known or to be developed in the future.

The term “network function (NF) ” refers to any suitable function which can be implemented in a network entity or node (physical or virtual) of a communication network. For example, a network function can be implemented either as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, or as a virtualized function instantiated on an appropriate platform, e.g. on a cloud infrastructure. For example, the 5G system (5GS) may comprise a plurality of NFs such as AMF (Access and mobility Function) , SMF (Session Management Function) , AUSF (Authentication Service Function) , UDM (Unified Data Management) , PCF (Policy Control Function) , AF (Application Function) , NEF (Network Exposure Function) , UPF (User plane Function) and NRF (Network Repository Function) , RAN (radio access network) , SCP (service communication proxy) , NWDAF (network data analytics function) , etc. For example, the 4G system (such as LTE) may include MME (Mobile Management Entity) , HSS (home subscriber server) , SCEF (service capability exposure function) , etc. In other embodiments, the network function may comprise different types of NFs for example depending on a specific network.

The term “network node” refers to an access network node or a core network node. The core network node may be a network's core part, which may offer numerous services to the customers who are interconnected by the access network node. The access network node may enable a terminal device to access to the network and receives services therefrom.

The term “terminal device” refers to any end device that can access a communication network and receive services therefrom. By way of example and not limitation, the terminal device refers to a mobile terminal, user equipment (UE) , or other suitable devices. The UE may be, for example, a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a portable computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and a playback appliance, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet, a wearable device, a personal digital assistant (PDA) , a portable computer, a desktop computer, a wearable terminal device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop-embedded equipment (LEE) , a laptop-mounted equipment (LME) , a USB (Universal Serial Bus) dongle, a smart device, a wireless customer-premises equipment (CPE) and the like. In the following description, the terms “terminal device” , “terminal” , “user equipment” and “UE” may be used interchangeably. As one example, a terminal device may represent a UE configured for communication in accordance with one or more communication standards promulgated by the 3GPP, such as 3GPP’ LTE standard or NR standard. As used herein, a “user equipment” or “UE” may not necessarily have a “user” in the sense of a human user who owns and/or operates the relevant device. In some embodiments, a terminal device may be configured to transmit and/or receive information without direct human interaction. For instance, a terminal device may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the communication network. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but that may not initially be associated with a specific human user.

As yet another example, in an Internet of Things (IoT) scenario, a terminal device may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another terminal device and/or network equipment. The terminal device may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as a machine-type communication (MTC) device. As one particular example, the terminal device may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, for example refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a terminal device may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

References in the specification to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed terms.

As used herein, the phrases “at least one of A or B” and “at least one of A and B” should be understood to mean “only A, only B, or both A and B. ” The phrase “Aand/or B” should be understood to mean “only A, only B, or both A and B. ”

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

It is noted that these terms as used in this document are used only for ease of description and differentiation among nodes, devices or networks etc. With the development of the technology, other terms with the similar/same meanings may also be used.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

It is noted that some embodiments of the present disclosure are mainly described in relation to the cellular network as defined by 3GPP being used as non-limiting examples for certain exemplary network configurations and system deployments. As such, the description of exemplary embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples and embodiments, and does naturally not limit the present disclosure in any way. Rather, any other system configuration or radio technologies such as wireless sensor network may equally be utilized as long as exemplary embodiments described herein are applicable.

FIGs. 1a-1c show some system architectures in which the embodiments of the present disclosure can be implemented. For simplicity, the system architectures of FIGs. 1a-1c only depict some exemplary elements. In practice, a communication system may further include any additional elements suitable to support communication between terminal devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or terminal device. The communication system may provide communication and various types of services to one or more terminal devices to facilitate the terminal devices’ access to and/or use of the services provided by, or via, the communication system.

FIG. 1a schematically shows system architecture in a 4G network according to an embodiment of the present disclosure, which is the same as Figure 4.2-1a of 3GPP TS 23.682 V17.0.0, the disclosure of which is incorporated by reference herein in its entirety. The system architecture of FIG. 1a may comprise some exemplary elements such as Services Capability Server (SCS) , Application Server (AS) , SCEF (Service Capability Exposure Function) , HSS, UE, RAN(Radio Access Network) , SGSN (Serving GPRS (General Packet Radio Service) Support Node) , MME, MSC (Mobile Switching Centre) , S-GW (Serving Gateway) , GGSN/P-GW (Gateway GPRS Support Node/PDN (Packet Data Network) Gateway) , MTC-IWF (Machine Type Communications-InterWorking Function) CDF/CGF (Charging Data Function/Charging Gateway Function) , MTC-AAA (Machine Type Communications-authentication, authorization and accounting) , SMS-SC/GMSC/IWMSC (Short Message Service-Service Centre/Gateway MSC/InterWorking MSC) IP-SM-GW (Internet protocol Short Message Gateway) . The network elements and interfaces as shown in FIG. 1a may be same as the corresponding network elements and interfaces as described in 3GPP TS 23.682 V17.0.0.

The system architecture shows the architecture for a UE used for MTC connecting to the 3GPP network (UTRAN (Universal Terrestrial Radio Access Network) , E-UTRAN (Evolved UTRAN) , GERAN (GSM EDGE (Enhanced Data rates for GSM Evolution) Radio Access Network) , etc. ) via the Um/Uu/LTE-Uu interfaces. The system architecture also shows the 3GPP network service capability exposure to SCS and AS.

As further illustrated in FIG. 1a, the exemplary system architecture also contains various reference points.

Tsms: Reference point used by an entity outside the 3GPP network to communicate with UEs used for MTC via SMS (Short Message Service) .

Tsp: Reference point used by a SCS to communicate with the MTC-IWF related control plane signalling.

T4: Reference point used between MTC-IWF and the SMS-SC in the HPLMN.

T6a: Reference point used between SCEF and serving MME.

T6b: Reference point used between SCEF and serving SGSN.

T8: Reference point used between the SCEF and the SCS/AS.

S6m: Reference point used by MTC-IWF to interrogate HSS/HLR (Home Location Register) .

S6n: Reference point used by MTC-AAA to interrogate HSS/HLR.

S6t: Reference point used between SCEF and HSS.

SGs: Reference point used between MSC and MME.

Gi/SGi: Reference point used between GGSN/P-GW and application server and between GGSN/P-GW and SCS.

Rf/Ga: Reference point used between MTC-IWF and CDF/CGF.

Gd: Reference point used between SMS-SC/GMSC/IWMSC and SGSN.

SGd: Reference point used between SMS-SC/GMSC/IWMSC and MME.

E: Reference point used between SMS-SC/GMSC/IWMSC and MSC.

The end-to-end communications, between the MTC Application in the UE and the MTC Application in the external network, uses services provided by the 3GPP system, and optionally services provided by a Services Capability Server (SCS) .

The MTC Application in the external network is typically hosted by an Application Server (AS) and may make use of an SCS for additional value added services. The 3GPP system provides transport, subscriber management and other communication services including various architectural enhancements motivated by, but not restricted to, MTC (e.g. control plane device triggering) .

Different models are foreseen for machine type of traffic in what relates to the communication between the AS and the 3GPP system and based on the provider of the SCS. The different architectural models that are supported by the Architectural Reference model include the Direct model, Indirect model and Hybrid model as described in 3GPP TS 23.682 V17.0.0.

FIG. 1b schematically shows a high level architecture in the fifth generation network according to an embodiment of the present disclosure. For example, the fifth generation network may be 5GS. The architecture of FIG. 1b is same as Figure 4.2.3-1 as described in 3GPP TS 23.501 V17.0.0, the disclosure of which is incorporated by reference herein in its entirety. The system architecture of FIG. 1b may comprise some exemplary elements such as AUSF, AMF, DN (data network) , NEF, NRF, NSSF, PCF, SMF, UDM, UPF, AF, UE, (R) AN, SCP (Service Communication Proxy) , NSSAAF (Network Slice-Specific Authentication and Authorization Function) , NSACF (Network Slice Admission Control Function) , etc.

In accordance with an exemplary embodiment, the UE can establish a signaling connection with the AMF over the reference point N1, as illustrated in FIG. 1b. This signaling connection may enable NAS (Non-access stratum) signaling exchange between the UE and the core network, comprising a signaling connection between the UE and the (R) AN and the N2 connection for this UE between the (R) AN and the AMF. The (R) AN can communicate with the UPF over the reference point N3. The UE can establish a protocol data unit (PDU) session to the DN (data network, e.g. an operator network or Internet) through the UPF over the reference point N6.

As further illustrated in FIG. 1b, the exemplary system architecture also contains the service-based interfaces such as Nnrf, Nnef, Nausf, Nudm, Npcf, Namf, Nnsacf and Nsmf exhibited by NFs such as the NRF, the NEF, the AUSF, the UDM, the PCF, the AMF, the NSACF and the SMF. In addition, FIG. 1b also shows some reference points such as N1, N2, N3, N4, N6 and N9, which can support the interactions between NF services in the NFs. For example, these reference points may be realized through corresponding NF service-based interfaces and by specifying some NF service consumers and providers as well as their interactions in order to perform a particular system procedure.

Various NFs shown in FIG. 1b may be responsible for functions such as session management, mobility management, authentication, security, etc. The AUSF, AMF, DN, NEF, NRF, NSSF, PCF, SMF, UDM, UPF, AF, UE, (R) AN, SCP, NSACF may include the functionality for example as defined in clause 6.2 of 3GPP TS 23.501 V17.0.0.

FIG. 1c schematically shows a system architecture for service exposure for EPC (evolved packet core) -5GC (5G core network) interworking according to an embodiment of the present disclosure, which is the same as Figure 4.3.5.1-1 of 3GPP TS 23.501 V17.1.1. For example, if a UE is capable of mobility between EPS (evolved packet system) and 5GS (5G system) , the network (such as EPC or 5GC ) is expected to associate the UE with a combined SCEF and NEF (also called an SCEF+NEF node) for service capability exposure. The system architecture of FIG. 1c may comprise some exemplary elements such as AF/AS, SCEF+NEF, EPC node, NF, etc. The network elements and interfaces as shown in FIG. 1c may be same as the corresponding network elements and interfaces as described in 3GPP TS 23.501 V17.1.1.

FIG. 2 shows a flowchart of a method according to an embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as an exposure function node or communicatively coupled to the exposure function node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 200 as well as means or modules for accomplishing other processes in conjunction with other components. The exposure function node may be any suitable network function which can implement network exposure function and/or service capability exposure function.

In an embodiment, the exposure function node may comprise at least one of a SCEF, a NEF, or a combined SCEF and NEF for example as shown in FIGs. 1a, 1b and 1c.

At block 202, the exposure function node may receive a first monitoring request from an application node.

The application node may be any suitable server or function in which various types of applications can be installed. In an embodiment, the application node comprises at least one of AS, SCS, or AF for example as shown in FIGs. 1a, 1b and 1c.

The first monitoring request may be any suitable message. For example, the first monitoring request may be used for subscribing an event report. In an embodiment, the first monitoring request comprises at least one of a Monitoring Request as described in 3GPP TS 23.682 V17.0.0, or an Nnef_EventExposure_Subscribe request as described in 3GPP TS 23.502 V17.1.0.

At block 204, the exposure function node may send a second monitoring request to a first network node.

The first network node may be any suitable network function which can detect the subscribed event or forward/send the monitoring request to any other suitable network node. In an embodiment, the first network node comprises at least one of HSS, MME, SGSN, AMF, SMF, or UDM for example as shown in FIGs. 1a, 1b and 1c.

The second monitoring request may be any suitable message. For example, the second monitoring request may be used for subscribing an event report. In an embodiment, the second monitoring request comprises at least one of a Monitoring Request message as described in 3GPP TS 23.682 V17.0.0, an Nudm_EventExposure_Subscribe request, an Namf_EventExposure_Subscribe request, or an Nsmf_EventExposure_Subscribe request as described in 3GPP TS 23.502 V17.1.0.

In an embodiment, the first monitoring request and the second monitoring request are used for monitoring at least one of user equipment (UE) reachability; location of the UE; change in location of the UE; loss of connectivity; communication failure; roaming status of the UE; change in roaming status of the UE; number of UEs present in a geographical area; availability after DDN (Digital Data Network) failure; or PDN (Packet Data Network) connectivity status. In other embodiment, the first monitoring request and the second monitoring request are used for any other suitable monitoring event for example as described in clause 4.5.6 of 3GPP TS 23.682 V17.0.0.

In an embodiment, the first monitoring request and/or the second monitoring request comprises information indicating event reporting interval and/or event reporting frequency. The information indicating event reporting interval and/or event reporting frequency may be any suitable information such as bit (s) , indication, flag, bit, etc. In an embodiment, the first monitoring request and/or the second monitoring request comprises the event reporting interval and/or the event reporting frequency.

In an embodiment, the first monitoring request comprises information indicating event reporting interval and/or event reporting frequency and the second monitoring request does not comprise information indicating event reporting interval and/or event reporting frequency. The exposure function node may store the information indicating event reporting interval and/or event reporting frequency. The exposure function node may receive event notification messages corresponding to the first monitoring request from other network node (s) according to the existing specifications or protocols and then may send the event notification messages to the application node based on the event reporting interval and/or event reporting frequency.

In an embodiment, the first monitoring request does not comprise information indicating event reporting interval and/or event reporting frequency and the second monitoring request comprises information indicating event reporting interval and/or event reporting frequency. For example, the information indicating event reporting interval and/or event reporting frequency may be preconfigured/configured in the exposure function node. The exposure function node may receive event notification messages corresponding to the first monitoring request which may be sent by another network node based on the event reporting interval and/or event reporting frequency. In this case, the exposure function node may send the received event notification messages to the application node without checking the event reporting interval and/or event reporting frequency. Alternatively, the exposure function node may send the received event notification messages to the application node based on the event reporting interval and/or event reporting frequency.

In an embodiment, the first monitoring request comprises information indicating event reporting interval and/or event reporting frequency and the second monitoring request comprises information indicating event reporting interval and/or event reporting frequency. The exposure function node may receive event notification messages corresponding to the first monitoring request which may be sent by another network node based on the event reporting interval and/or event reporting frequency. In this case, the exposure function node may send the received event notification messages to the application node without checking the event reporting interval and/or event reporting frequency. Alternatively, the exposure function node may send the received event notification messages to the application node based on the event reporting interval and/or event reporting frequency.

The event reporting interval indicates the interval to report the event, i.e. when an event is reported, a subsequent event report shall be sent according to the event reporting interval. In an embodiment, the event reporting interval comprises minimal event reporting interval.

The event reporting frequency indicates the frequency to report the event, i.e. when an event is reported, a subsequent event report shall be sent according to the event reporting frequency. In an embodiment, the event reporting frequency comprises minimal event reporting frequency.

In an embodiment, the event reporting interval indicates a minimal interval to report an event (or called minimal event reporting interval) . The minimal event reporting interval indicates the minimal interval to report the event, i.e. when an event is reported, a subsequent event report shall not be sent during the interval.

In an embodiment, the event reporting frequency indicates a minimal frequency to report an event (or called minimal event reporting frequency) . The minimal event reporting frequency indicates the minimal frequency to report the event, i.e. when an event is reported, a sending frequency of the event report shall not exceed the minimal event reporting frequency.

FIG. 3a shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as an exposure function node or communicatively coupled to the exposure function node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 300 as well as means or modules for accomplishing other processes in conjunction with other components. The exposure function node may be any suitable network function which can implement network exposure function and/or service capability exposure function. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 302, the exposure function node may receive a first event notification message comprising an event report related to the first monitoring request from a network node. The network node may be any suitable network which has detected a monitoring event related to the first monitoring request. For example, the network node may be the first network node, a second network node or a third network node as described below.

The first event notification message may be any suitable message. In an embodiment, the first event notification message comprises at least one of a Monitoring Indication message, a Monitoring Response message as described in 3GPP TS 23.682 V17.0.0, an Nudm_EventExposure_Notify message, an Namf_EventExposure_Notify message, or an Nsmf_EventExposure_Notify message as described in 3GPP TS 23.502 V17.1.0.

In an embodiment, the first event notification message is sent to the exposure function node based on the event reporting interval and/or event reporting frequency. For example, when the network node knows the event reporting interval and/or event reporting frequency for example from a monitoring request received from the exposure function node or another network node or from monitoring event configuration information received from another network node, it may send the first event notification message comprising the monitoring event to the exposure function node based on the event reporting interval and/or event reporting frequency.

In another embodiment, the first event notification message is sent to the exposure function node according to the existing specifications or protocols.

At block 304, the exposure function node may send a second event notification message comprising the event report related to the first monitoring request to the application node.

The second event notification message may be any suitable message. In an embodiment, the second event notification message comprises at least one of a Monitoring Indication message, a Monitoring Response message as described in 3GPP TS 23.682 V17.0.0, or an Nnef_EventExposure_Notify message as described in 3GPP TS 23.502 V17.1.0.

In an embodiment, the second event notification message is sent to the application node based on the event reporting interval and/or event reporting frequency. For example, when the first event notification message is sent to the exposure function node based on the event reporting interval and/or event reporting frequency, the exposure function node may send the second event notification message to the application node without checking the event reporting interval and/or event reporting frequency. Alternatively, the exposure function node may send the second event notification message to the application node based on the event reporting interval and/or event reporting frequency.

FIG. 3b shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as NEF or communicatively coupled to the NEF. As such, the apparatus may provide means or modules for accomplishing various parts of the method 310 as well as means or modules for accomplishing other processes in conjunction with other components. The exposure function node may be any suitable network function which can implement network exposure function and/or service capability exposure function. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 312, the NEF may receive a first monitoring request from an application node.

At block 314, the NEF may send a second monitoring request to a Unified Data Management, UDM.

In an embodiment, the first monitoring request and/or the second monitoring request comprises information indicating event reporting interval,

In an embodiment, the event reporting interval indicates a minimal interval to report an event,

In an embodiment, the first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.

FIG. 4a shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as an application node or communicatively coupled to the application node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 400 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 402, the application node may send a first monitoring request to an exposure function node.

At block 404, the application node may receive a second event notification message from the exposure function node. The second event notification message is sent to the application node based on event reporting interval and/or event reporting frequency.

In an embodiment, the first monitoring request comprises the information indicating the event reporting interval and/or the event reporting frequency.

In an embodiment, the first monitoring request is used for monitoring at least one of user equipment (UE) reachability; location of the UE; change in location of the UE; loss of connectivity; communication failure; roaming status of the UE; change in roaming status of the UE; number of UEs present in a geographical area; availability after DDN (Digital Data Network) failure; or PDN (Packet Data Network) connectivity status.

In an embodiment, the event reporting interval comprises minimal event reporting interval.

In an embodiment, the event reporting frequency comprises minimal event reporting frequency.

In an embodiment, the event reporting interval indicates a minimal interval to report an event.

In an embodiment, the event reporting frequency indicates a minimal frequency to report an event.

In an embodiment, the exposure function node comprises at least one of a SCEF, a NEF, or a combined SCEF and NEF.

In an embodiment, the application node comprises at least one of AS, SCS, or AF.

FIG. 4b shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as an application node or communicatively coupled to the application node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 410 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 412, the application node may send a first monitoring request to an exposure function node.

At block 414, the application node may a second event notification message from the NEF.

In an embodiment, the second event notification message is sent to the application node based on event reporting interval,

In an embodiment, the first monitoring request is used for monitoring user equipment (UE) reachability.

FIG. 5 shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a first network node or communicatively coupled to the first network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 500 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 502, the first network node may receive a second monitoring request from an exposure function node. The second monitoring request comprises information indicating event reporting interval and/or event reporting frequency.

In an embodiment, the second monitoring request is used for monitoring at least one of user equipment (UE) reachability; location of the UE; change in location of the UE; loss of connectivity; communication failure; roaming status of the UE; change in roaming status of the UE; number of UEs present in a geographical area; availability after DDN (Digital Data Network) failure; or PDN (Packet Data Network) connectivity status.

In an embodiment, the first network node comprises at least one of HSS, MME, SGSN, AMF, SMF, or UDM.

After receiving the second monitoring request from the exposure function node, the first network node may process the second monitoring request for example according to FIGs. 6-8.

FIG. 6 shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a first network node or communicatively coupled to the first network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 600 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 602, the first network node may receive a second monitoring request from an exposure function node. The second monitoring request comprises information indicating event reporting interval and/or event reporting frequency. Block 602 is same as block 502 of FIG. 5.

At block 604, the first network node may detect a monitoring event related to the second monitoring request

At block 606, the first network node may send a first event notification message comprising the monitoring event to an exposure function node based on the event reporting interval and/or the event reporting frequency.

FIG. 7 shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a first network node or communicatively coupled to the first network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 700 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 702, the first network node may receive a second monitoring request from an exposure function node. The second monitoring request comprises information indicating event reporting interval and/or event reporting frequency. Block 702 is same as block 502 of FIG. 5.

At block 704, the first network node may send a third monitoring request to a second network node. The third monitoring request comprises the information indicating the event reporting interval and/or the event reporting frequency. The second network node may be any suitable network node which can support monitoring event (s) of the first monitoring request.

In an embodiment, the first network node comprises at least one of HSS or UDM.

In an embodiment, the second network node comprises at least one of MME, SGSN, AMF, or SMF.

In an embodiment, the third monitoring request is used for monitoring at least one of user equipment (UE) reachability; location of the UE; change in location of the UE; loss of connectivity; communication failure; roaming status of the UE; change in roaming status of the UE; number of UEs present in a geographical area; availability after DDN (Digital Data Network) failure; or PDN (Packet Data Network) connectivity status.

FIG. 8a shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a first network node or communicatively coupled to the first network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 800 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 802, the first network node may receive a second monitoring request from an exposure function node. The second monitoring request comprises information indicating event reporting interval and/or event reporting frequency. Block 802 is same as block 502 of FIG. 5.

At block 804, the first network node may send monitoring event configuration information to a third network node. The monitoring event configuration information comprises the information indicating the event reporting interval and/or the event reporting frequency.

In an embodiment, the monitoring event configuration information is sent during at least one of a procedure of UE moving from 5GS to EPS; a procedure of UE moving from EPS to 5GS; a registration procedure with a change of AMF; a procedure with SMF change; or an Inter NG-RAN node N2 based handover procedure with a change of AMF for example as described in various 3GPP specifications such as 3GPP TS 23.502 V17.1.0.

In an embodiment, the monitoring event configuration information further comprises information indicating remain time of the event reporting interval. The remain time of the event reporting interval may indicate a time point before which a subsequent event report shall be throttled.

In an embodiment, the third network node comprises at least one of a new first network node or a network node in another communication network different from a communication network of the first network node. For example, the first network node may be MME and the third network node may be AMF in the procedure of UE moving from EPS to 5GS. The first network node may be AMF and the third network node may be MME in the procedure of UE moving from 5GS to EPS. The first network node may be an old AMF and the third network node may be a new AMF in the registration procedure with a change of AMF or the Inter NG-RAN node N2 based handover procedure with a change of AMF.

FIG. 8b shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a UDM or communicatively coupled to the UDM. As such, the apparatus may provide means or modules for accomplishing various parts of the method 810 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 812, the UDM may receive a second monitoring request from an NEF. The second monitoring request is used for monitoring user equipment (UE) reachability and comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event.

At block 814, the UDM may send a third monitoring request to an AMF. The third monitoring request comprises the information indicating the event reporting interval

FIG. 9 shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a second network node or communicatively coupled to the second network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 900 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 902, the second network node may receive a third monitoring request from a first network node. The third monitoring request comprises information indicating event reporting interval and/or event reporting frequency.

In an embodiment, the first network node comprises at least one of HSS, or UDM.

After receiving the third monitoring request from the first network node, the second network node may process the third monitoring request for example according to FIG. 10 or FIG. 11.

FIG. 10 shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a second network node or communicatively coupled to the second network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 1000 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 1002, the second network node may receive a third monitoring request from a first network node. The third monitoring request comprises information indicating event reporting interval and/or event reporting frequency.

At block 1004, the second network node may detect a monitoring event related to the third monitoring request.

At block 1006, the second network node may send a first event notification message comprising the monitoring event to an exposure function node based on the event reporting interval and/or the event reporting frequency.

FIG. 11a shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a second network node or communicatively coupled to the second network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 1100 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 1102, the second network node may receive a third monitoring request from a first network node. The third monitoring request comprises information indicating event reporting interval and/or event reporting frequency.

At block 1104, the second network node may send monitoring event configuration information to a third network node. The monitoring event configuration information comprises the information indicating the event reporting interval and/or the event reporting frequency.

In an embodiment, the monitoring event configuration information is sent during at least one of a procedure of UE moving from 5GS to EPS; a procedure of UE moving from EPS to 5GS; a registration procedure with a change of AMF; a procedure with SMF change; or an Inter NG-RAN node N2 based handover procedure with a change of AMF.

In an embodiment, the monitoring event configuration information further comprises information indicating remain time of the event reporting interval.

FIG. 11b shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as an AMF or communicatively coupled to the AMF. As such, the apparatus may provide means or modules for accomplishing various parts of the method 1110 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 1112, the AMF may receive a third monitoring request for monitoring user equipment (UE) reachability from a UDM. The third monitoring request comprises information indicating event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event.

At block 1114, the AMF may detect a monitoring event related to the third monitoring request; and

At block 1116, the AMF may send a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

FIG. 12 shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a third network node or communicatively coupled to the third network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 1200 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 1202, the third network node may receive monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and/or event reporting frequency.

In an embodiment, the monitoring event configuration information is used for monitoring at least one of user equipment (UE) reachability; location of the UE; change in location of the UE; loss of connectivity; communication failure; roaming status of the UE; change in roaming status of the UE; number of UEs present in a geographical area; availability after DDN (Digital Data Network) failure; or PDN (Packet Data Network) connectivity status.

In an embodiment, the third network node comprises at least one of MME, SGSN, AMF, or SMF.

After receiving the monitoring event configuration information from the network node, the third network node may perform operations according to FIG. 13 or FIG. 14.

FIG. 13 shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a third network node or communicatively coupled to the third network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 1300 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 1302, the third network node may receive monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and/or event reporting frequency.

In an embodiment, the monitoring event configuration information is received during at least one of a procedure of UE moving from 5GS to EPS; a procedure of UE moving from EPS to 5GS; a registration procedure with a change of AMF; a procedure with SMF change; or an Inter NG-RAN node N2 based handover procedure with a change of AMF.

At block 1304, the third network node may detect a monitoring event related to the monitoring event configuration information.

At block 1306, the third network node may send an event notification message comprising the monitoring event to an exposure function node based on the event reporting interval and/or the event reporting frequency.

FIG. 14a shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a third network node or communicatively coupled to the third network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 1400 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 1402, the third network node may receive monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and/or event reporting frequency.

At block 1404, the third network node may send the monitoring event configuration information to a fourth network node. The monitoring event configuration information comprises the information indicating the event reporting interval and/or the event reporting frequency.

In an embodiment, the fourth network node comprises at least one of a new fourth network node, or a network node in another communication network different from a communication network of the fourth network node.

FIG. 14b shows a flowchart of a method according to another embodiment of the present disclosure, which may be performed by an apparatus implemented in or at or as a third network node or communicatively coupled to the third network node. As such, the apparatus may provide means or modules for accomplishing various parts of the method 1410 as well as means or modules for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, the description thereof is omitted here for brevity.

At block 1412, the third network node may receive monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and information indicating remain time of the event reporting interval. The event reporting interval indicates a minimal interval to report an event;

At block 1414, the third network node may detect a monitoring event related to the monitoring event configuration information.

At block 1416, the third network node may send an event notification message comprising the monitoring event to an NEF based on the event reporting interval and the remain time of the event reporting interval.

FIG. 15 shows a flowchart for configuring the maximum UE reachability event report frequency initiated by AS/SCS through SCEF in 4G EPC according to an embodiment of the present disclosure.

At step 1. The SCS/AS sends a Monitoring Request (External Identifier or MSISDN (Mobile Subscriber ISDN (Integrated Services Digital Network) Number) or External Group ID (identifier) , SCS/AS Identifier, Monitoring Type, Maximum Number of Reports, Monitoring Duration, T8 Destination Address, TLTRI (T8 Long Term Transaction Reference ID) for Deletion, Group Reporting Guard Time, MTC Provider Information, and Minimum Report Interval if it is a continuous report) message to the SCEF. The SCEF assigns a TLTRI that identifies the Monitoring Request. If the SCS/AS may perform deletion of a previously configured Monitoring Event together with configuring a new Monitoring Event. If the SCS/AS wants to perform deletion of a previously configured Monitoring Event, then it shall include TLTRI for Deletion.

At step 2. The SCEF stores SCS/AS Identifier, T8 Destination Address, Monitoring Duration, Maximum Number of Reports, Minimum Report Interval and Group Reporting Guard Time, if provided. The SCEF stores the TLTRI, and also assigns it to an SCEF Reference ID. Based on operator policies, if either the SCS/AS is not authorized to perform this request (e.g. if the SLA (Service Level Agreement) does not allow for it) or the Monitoring Request is malformed or the SCS/AS has exceeded its quota or rate of submitting monitoring requests, the SCEF performs step 9 of FIG. 15 and provides a Cause value appropriately indicating the error. If the SCEF received a TLTRI for Deletion, the SCEF looks up the SCEF context pointed to by the TLTRI to derive the related SCEF Reference ID for Deletion.

The SCEF sends a Monitoring Request (External Identifier or MSISDN or External Group Identifier, SCEF ID, SCEF Reference ID, Monitoring Type, Maximum Number of Reports, Monitoring Duration, SCEF Reference ID for Deletion, Chargeable Party Identifier, Group Reporting Guard Time, MTC Provider Information, Minimum Report Interval) message to the HSS to configure the given Monitoring Event on the HSS and on the MME/SGSN, if required. If the External Group Identifier is included, External Identifier or MSISDN shall be ignored. For one-time Monitoring Request of Roaming Status, the SCEF does not indicate the Group Reporting Guard Time.

The HSS examines the Monitoring Request message, e.g. with regard to the existence of External Identifier or MSISDN or External Group Identifier, whether any included parameters are in the range acceptable for the operator, whether the monitoring event (s) is supported by the serving MME/SGSN, whether the group-basis monitoring event feature is supported by the serving MME/SGSN, or whether the monitoring event that shall be deleted is valid. The HSS optionally authorizes the chargeable party identified by Chargeable Party Identifier. If this check fails the HSS follows step 5 of FIG. 15 and provides a Cause value indicating the reason for the failure condition to the SCEF.

The HSS stores the SCEF Reference ID, the SCEF ID, Maximum Number of Reports, Monitoring Duration, Minimum Report Interval and the SCEF Reference ID for Deletion as provided by the SCEF. For a Monitoring Request for a group, such parameters are stored for every group member UE.

At step 3. If required by the specific Monitoring Type and when Monitoring Event (s) is supported by the serving MME/SGSN, the HSS sends an Insert Subscriber Data Request (Monitoring Type, SCEF ID, SCEF Reference ID, Maximum Number of Reports, Monitoring Duration, SCEF Reference ID for Deletion, Chargeable Party Identifier, Minimum Report Interval) message to the MME/SGSN for each individual UE and for each individual group member UE. If the Monitoring Request message is for a group of UEs, for each UE group member, the HSS includes the selected External ID or the MSISDN in the monitoring event configuration and sends an Insert Subscriber Data Request message per UE to all the MME/SGSN (s) serving the members of the group. Optionally, the HSS allocates a Provider-Group-ID based on the MTC Provider Information (different from the IMSI-Group-Id) and sends it to the MME/SGSN to assist the serving node (s) when selecting and differentiating configurations for a given MTC Service Provider (e.g. to delete the configurations for a specific MTC Service Provider at the MME/SGSN) .

If the MME/SGSN is configured to use an IWK-SCEF for the PLMN of the SCEF then clause 5.6.6 of 3GPP TS 23.682 V17.0.0 applies. Otherwise, the MME/SGSN verifies the request, e.g. if the Monitoring Type is covered by a roaming agreement when the request is from another PLMN or whether it serves the SCEF Reference ID for Deletion and can delete it. If this check fails, the MME/SGSN follows step 7 of FIG. 15 and provides a Cause value indicating the reason for the failure condition to the HSS. Based on operator policies, the MME/SGSN may also reject the request due to other reasons (e.g. overload or HSS has exceeded its quota or rate of submitting monitoring requests defined by an SLA) .

The MME/SGSN stores the received parameters including Minimum Report Interval and starts to watch for the indicated Monitoring Event unless it is a One-time request and the Monitoring Event is available to the MME/SGSN at the time of sending Insert Subscriber Data Answer. The MME/SGSN deletes the monitoring configuration identified by the SCEF Reference ID for Deletion, if provided.

The MME/SGSN will transfer the parameters stored and the remain time of the report interval for every monitoring task as part of its context information during an MME/SGSN change.

At step 4. If the monitoring configuration is successful, the MME/SGSN sends an Insert Subscriber Data Answer (Cause) message to the HSS. If the requested Monitoring Event is available to the MME/SGSN at the time of sending Insert Subscriber Data Answer, then the MME/SGSN includes the Monitoring Event Report in the Insert Subscriber Data Answer message.

At step 5. For single UE processing, the HSS sends a Monitoring Response (SCEF Reference ID, Cause, Monitoring Event Report) message to the SCEF to acknowledge acceptance of the Monitoring Request and the deletion of the identified monitoring event configuration, if it was requested. The HSS deletes the monitoring event configuration identified by the SCEF Reference ID, if it was requested. If the requested Monitoring Event is available to the HSS at the time of sending Monitoring Response message or was received from the MME/SGSN in step 7 of FIG. 15, then the HSS includes a Monitoring Event Report in the Monitoring Response message.

For group-based processing, if the HSS sent the Monitoring Response in step 4a of FIG. 15, i.e. due to having received a Monitoring Request with an External Group Identifier and if the Group Reporting Guard Time was provided in the Monitoring Request message, the HSS accumulates multiple responses for the UEs of the group within the Group Reporting Guard Time. After the Group Reporting Guard Time expiration, the HSS sends a Monitoring Indication with the accumulated responses. The HSS includes UE identity (ies) and a Cause value indicating the reason for the failure in the message if the monitoring configuration of the group member failed.

For the group-basis Monitoring Event configuration, the HSS may divide the accumulated Monitoring Indications into multiple messages due to e.g. limitation of the message size.

At step 6a. For single UE processing, the SCEF sends a Monitoring Response (Cause, Monitoring Event Report) message to the SCS/AS to acknowledge acceptance of the Monitoring Request and the deletion of the identified monitoring event configuration, if it was requested. If the SCEF received a Monitoring Event Report then it includes the Monitoring Event Report in the Monitoring Response message. If it is a One-time request for an individual UE and the Monitoring Response includes a Monitoring Event Report for the UE, the SCEF deletes the associated Monitoring Event configuration.

At step 6b. For group-based processing, if no Group Reporting Guard Time was set, then the SCEF sends the Monitor Indication (TLTRI, Cause, Monitoring Event Report) message to the SCS/AS as it receives them from the HSS. Otherwise, it accumulates Monitoring Event for the UEs of the group until the expiration of Group Reporting Guard Time. Upon expiration, the SCEF sends a Monitoring Indication (TLTRI, Cause, list of (External Identifier or MSISDN, Monitoring Event Report) ) message to the SCS/AS. A list of accumulated Monitoring Event Report for each UE identified by either External Identifier or MSISDN is also included.

At step 6c. For each Monitoring Indication message received in step 6b of FIG. 15, the SCS/AS sends a Monitoring Indication Response (Cause) message to the SCEF. Cause value reflects successful or unsuccessful acknowledgement of Monitoring Indication message.

At step 7a-7b. A Monitoring Event is detected by the HSS. The HSS also stores the time when the Event is detected. Depends on the subscribed minimum report interval (if available) and local policy, it can discard or buffer the event if minimum report interval is not reached, and it can also send a Monitoring Indication (SCEF Reference ID (s) , External ID or MSISDN, Monitoring Event Report) message to the SCEF.

At step 7c-7d. A Monitoring Event is detected by the MME/SGSN at which the Monitoring Event is configured. Depends on the subscribed minimum report interval (if available) and local policy, the MME/SGSN can discard or buffer the event if minimum report interval is not reached, and it can also send a Monitoring Indication (SCEF Reference ID (s) , Monitoring Event Report, User Identity) message to the SCEF. The SCEF store the time when it receives the Monitoring Indication. Using the SCEF Reference ID, the SCEF retrieves the associated TLTRI along with the T8 Destination Address.

At step 8. For each event notification message received in step 7 of FIG. 15, depends on local policy, the SCEF may check the minimum report interval (if available) for the subscription and discard or buffer the event report if the minimum report interval is not reached. If the event report is discarded, the flow stops at this step. Otherwise, the flow continues with step 9 of FIG. 15.

At step 9. Using the SCEF Reference ID, the SCEF retrieves the associated TLTRI along with the T8 Destination Address. The SCEF sends the report to SCS/AS when the minimum reporting interval (if available) is reached or exceeded.

The messages as shown in FIG. 15 are similar to those as described in 3GPP TS 23.682 V17.0.0 except that some messages further comprises the minimum report interval and the Monitoring Indication is sent based on the minimum report interval.

FIG. 16 shows a flowchart for controlling the maximum event report frequency in 5GC and AF according to an embodiment of the present disclosure.

At step 1. The AF subscribes to one or several Event (s) (identified by Event ID) and provides the associated notification endpoint of the AF and minimum Report Interval optionally (e.g. continuous UE reachability report subscription) by sending Nnef_EventExposure_Subscribe request.

Event Reporting Information defines the type of reporting requested (e.g. one-time reporting, periodic reporting or event based reporting, for Monitoring Events) . If the reporting event subscription is authorized by the NEF, the NEF records the association of the event trigger and the requester identity. The subscription may also include Maximum number of reports and/or Maximum duration of reporting IE (information element) .

At step 2. [Conditional -depending on authorization in step 1 of FIG. 16] The NEF subscribes to received Event (s) (identified by Event ID) and provides the associated notification endpoint of the NEF to UDM by sending Nudm_EventExposure_Subscribe request. The NEF maps the AF-Identifier into DNN and S-NSSAI combination based on local configuration, and include DNN (Data Network Name) , S-NSSAI (Single Network Slice Selection Assistance Information) in the request.

If the reporting event subscription is authorized by the UDM, the UDM records the association of the event trigger and the requester identity. Otherwise, the UDM continues in step 4 of FIG. 16 indicating failure.

At step 3a. [Conditional] If the requested event (e.g. monitoring of UE reachability) requires AMF assistance, then the UDM sends the Namf_EventExposure_Subscribe to the AMF serving the requested user. The UDM sends the Namf_EventExposure_Subscribe request to the all serving AMF (s) (if subscription applies to a UE or a group of UE (s) ) , or all the AMF in the same PLMN as the UDM (if subscription applies to any UE) .

As the UDM itself is not the Event Receiving NF, the UDM shall additionally provide the notification endpoint of itself besides the notification endpoint of NEF. Each notification endpoint is associated with the related (set of) Event ID (s) . This is to assure the UDM can receive the notification of subscription change related event.

If the subscription applies to a group of UE (s) , the UDM shall include the same notification endpoint of itself, i.e. Notification Target Address (+ Notification Correlation Id) , in the subscriptions to all UE's serving AMF (s) .

The same notification endpoint of UDM is to help the AMF identify whether the subscription for the requested group event is same or not when a new group member UE is registered.

At step 3b. [Conditional] AMF acknowledges the execution of Namf_EventExposure_Subscribe.

At step 4. UDM acknowledges the execution of Nudm_EventExposure_Subscribe.

If the subscription is applicable to a group of UE (s) and the Maximum number of reports is included in the Event Report information in step 1 of FIG. 16, the Number of UEs is included in the acknowledgement.

At step 5. NEF acknowledges the execution of Nnef_EventExposure_Subscribe to the requester that initiated the request.

At step 6a-6b. [Conditional-depending on the Event] The UDM detects the subscribed event occurs. Depends on the subscribed minimum report interval (if available) and local policy, it can discard or buffer the event if minimum report interval is not reached, and it can also send the event report, by means of Nudm_EventExposure_Notify message, to the associated notification endpoint of the NEF, along with the time stamp.

At step 6c-6d. [Conditional-depending on the Event] The AMF detects the subscribed event occurs. Depends on the subscribed minimum report interval (if available) and local policy, it can discard or buffer the event if minimum report interval is not reached, and it can also send the event report, by means of Namf_EventExposure_Notify message, to the associated notification endpoint of the NEF, along with the time stamp. If the event is buffered, the AMF shall send the event when the minimum reporting interval is reached.

At step 7. For each event notification message received in step 6 of FIG. 16, depends on local policy, the NEF may check the minimum report interval (if available) for the subscription and discard/buffer the event report if the report interval is not reached. If the event report is discarded, the flow stops at this step. Otherwise, the flow continues with step 8 of FIG. 16.

At step 8. The NEF sends the report to AF by means of Nnef_EventExposure_Notify message when the minimum reporting interval (if available) is reached or exceeded.

The messages as shown in FIG. 16 are similar to those as described in 3GPP TS 23.502 V17.1.0 except that some messages further comprises the minimum report interval and the Nnef_EventExposure_Notify message is sent based on the minimum report interval.

In an embodiment, MME/AMF/SCEF/NEF/UDM shall limit the event reporting frequency based on the AF/AS configured minimum event report interval from SCS/AS/AF for Continuous UE event report subscription.

In an embodiment, SCS/AS/AF can use the T8/N33 interface to configure the minimum event report interval to MME/AMF/UDM via SCEF/NEF.

In an embodiment, the remain time of the interval and the subscribed minimum report interval as the part of monitoring event configuration information shall be transferred between MME and AMF when UE moves from 5GS to EPS or from EPS to5GS.

When UE moves from 5GS to EPS and Monitoring Events are offered via AMF, the UE context information sent by AMF to MME includes the monitoring event configuration information.

When UE moves from EPS to 5GS and Monitoring Events are offered via MME, the MME's MM context information sent by MME to AMF includes the monitoring event configuration information.

During Registration procedure, Inter NG-RAN node N2 based handover procedure, when there is a change of AMF, the remain time of the interval and the subscribed minimum report interval as the part of monitoring event configuration information shall be transferred from the old AMF to the new AMF.

In an embodiment, the monitoring event request massages as described in various 3GPP specifications such as 3GPP TS 23.502 V17.1.0 or 3GPP TS 23.682 V17.0.0 may further comprise information indicating event reporting interval and/or event reporting frequency.

In an embodiment, the event report massages as described in various 3GPP specifications such as 3GPP TS 23.502 V17.1.0 or 3GPP TS 23.682 V17.0.0 may be sent based on the event reporting interval and/or event reporting frequency.

In an embodiment, the monitoring event configuration information may further comprise information indicating event reporting interval and/or event reporting frequency when the monitoring event configuration information is transferred between any two network nodes. In addition, the monitoring event configuration information may further comprise information indicating remain time of the event reporting interval.

In an embodiment, it may introduce minimum UE reachability report interval IE in SCEF/NEF T8/N33 interface.

In an embodiment, it may introduce minimum UE reachability report interval IE in S6t interface between SCEF/SCEF+NEF and HSS.

In an embodiment, it may introduce minimum UE reachability report interval IE in S6a/d interface between HSS and MME.

In an embodiment, it may introduce minimum event report interval IE in following SBI interfaces in 5GC:

● Nnef_EventExposure_Subscribe

● Nudm_EventExposure_Subscribe

● Namf_EventExposure_Subscribe.

In an embodiment, Table 6.2.6.2.3-1of 3GPP TS 29.518 17.3.0 may add the following content.

Table 6.2.6.2.3-1: Definition of type AmfEvent

In an embodiment, Namf_EventExposure API of 3GPP TS 29.518 17.3.0 may be amended as following.

A.3 Namf_EventExposure API

In an embodiment, Table 6.4.6.2.21-1 of 3GPP TS 29.503 17.4.0 may be amended as following.

Table 6.4.6.2.21-1: Definition of type ReachabilityForDataConfiguration

In an embodiment, Nudm_EE API of 3GPP TS 29.503 17.4.0 may be amended as following.

The various blocks/steps shown in FIGs. 2-16 may be viewed as method steps, and/or as operations that result from operation of computer program code, and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function (s) . The schematic flow chart diagrams described above are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of specific embodiments of the presented methods. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated methods. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

Embodiments herein offer many advantages, of which a non-exhaustive list of examples follows. Some embodiments herein provide a mechanism for SCS/AS/AF to influence the event reporting frequency. Some embodiments herein ensure a minimum time gap between consecutive monitoring event report initiated by the network. Some embodiments herein help reducing peak load situations when a UE event report condition is met many times within a short time in an operator network. Some embodiments herein can be used for monitoring event reports for MTC/CIoT UEs where the applications are tolerant to service latency. Some embodiments herein can enable SCS/AS/AF to throttle the reporting of UE reachability event. Some embodiments herein can avoid unnecessary event report notifications to SCS/AS/AF and decrease traffic load and network node load. The embodiments herein are not limited to the features and advantages mentioned above. A person skilled in the art will recognize additional features and advantages upon reading the following detailed description.

FIG. 17 is a block diagram showing an apparatus suitable for practicing some embodiments of the disclosure. For example, any one of the exposure function node, the NEF, the application node, the first network node, the UDM, the second network node, the AMF or the third network node as described above may be implemented as or through the apparatus 1700.

The apparatus 1700 comprises at least one processor 1721, such as a digital processor (DP) , and at least one memory (MEM) 1722 coupled to the processor 1721. The apparatus 1720 may further comprise a transmitter TX and receiver RX 1723 coupled to the processor 1721. The MEM 1722 stores a program (PROG) 1724. The PROG 1724 may include instructions that, when executed on the associated processor 1721, enable the apparatus 1720 to operate in accordance with the embodiments of the present disclosure. A combination of the at least one processor 1721 and the at least one MEM 1722 may form processing means 1725 adapted to implement various embodiments of the present disclosure.

Various embodiments of the present disclosure may be implemented by computer program executable by one or more of the processor 1721, software, firmware, hardware or in a combination thereof.

The MEM 1722 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memories and removable memories, as non-limiting examples.

The processor 1721 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples.

In an embodiment where the apparatus is implemented as or at the exposure function node, the memory 1722 contains instructions executable by the processor 1721, whereby the exposure function node operates according to any step of any of the methods related to the exposure function node as described above.

In an embodiment where the apparatus is implemented as or at the application node, the memory 1722 contains instructions executable by the processor 1721, whereby the application node operates according to any step of the methods related to the application node as described above.

In an embodiment where the apparatus is implemented as or at the first network node, the memory 1722 contains instructions executable by the processor 1721, whereby the first network node operates according to any step of the methods related to the first network node as described above.

In an embodiment where the apparatus is implemented as or at the second network node, the memory 1722 contains instructions executable by the processor 1721, whereby the second network node operates according to any step of the methods related to the second network node as described above.

In an embodiment where the apparatus is implemented as or at the third network node, the memory 1722 contains instructions executable by the processor 1721, whereby the third network node operates according to any step of the methods related to the third network node as described above.

In an embodiment where the apparatus is implemented as or at the NEF, the memory 1722 contains instructions executable by the processor 1721, whereby the NEF operates according to any step of the methods related to the NEF as described above.

In an embodiment where the apparatus is implemented as or at the UDM, the memory 1722 contains instructions executable by the processor 1721, whereby the UDM operates according to any step of the methods related to the UDM as described above.

In an embodiment where the apparatus is implemented as or at the AMF, the memory 1722 contains instructions executable by the processor 1721, whereby the AMF operates according to any step of the methods related to the AMF as described above.

FIG. 18 is a block diagram showing an NEF according to an embodiment of the disclosure. As shown, the NEF 1800 comprises a first receiving module 1801 and a first sending module 1802. The first receiving module 1801 may be configured to receive a first monitoring request from an application node. The first sending module 1802 may be configured to send a second monitoring request to a UDM. The event reporting interval indicates a minimal interval to report an event. The first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.

In an embodiment, the exposure function node 1800 further comprises a second receiving module 1803 configured to receive a first event notification message comprising an event report related to the first monitoring request from a network node.

In an embodiment, the exposure function node 1800 further comprises a second sending module 1804 configured to send a second event notification message comprising the event report related to the first monitoring request to the application node.

FIG. 19 is a block diagram showing an application node according to an embodiment of the disclosure. As shown, the application node 1900 comprises a sending module 1901 and a receiving module 1902. The sending module 1901 may be configured to send a first monitoring request to an exposure function node. The receiving module 1902 may be configured to receive a second event notification message from the exposure function node. The second event notification message is sent to the application node based on event reporting interval. The event reporting interval indicates a minimal interval to report an event. The first monitoring request is used for monitoring user equipment (UE) reachability.

FIG. 20 is a block diagram showing a UDM according to an embodiment of the disclosure. As shown, the UDM 2000 comprises a receiving module 2001. The receiving module 2001 may be configured to receive a second monitoring request from an NEF. The second monitoring request is used for monitoring user equipment (UE) reachability and comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The UDM 2000 further comprises a third sending module 2005 configured to send a third monitoring request to an AMF. The third monitoring request comprises the information indicating the event reporting interval.

In an embodiment, the UDM further comprises a detecting module 2002 configured to detect a monitoring event related to the second monitoring request.

In an embodiment, the UDM further comprises a first sending module 2003 configured to send a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

In an embodiment, the UDM further comprises a second sending module 2004 configured to send monitoring event configuration information to a third network node. The monitoring event configuration information comprises the information indicating the event reporting interval.

. FIG. 21 is a block diagram showing a second network node according to an embodiment of the disclosure. As shown, the AMF 2100 comprises a receiving module 2001. The receiving module 2101 may be configured to receive a third monitoring request for monitoring user equipment (UE) reachability from a UDM. The third monitoring request comprises information indicating event reporting interval. The event reporting interval indicates a minimal interval to report an event. The AMF further comprises a detecting module 2102 configured to detect a monitoring event related to the third monitoring request. The AMF further comprises a first sending module 2103 configured to send a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.

In an embodiment, the second network node 2100 further comprises a second sending module 2104 configured to send monitoring event configuration information to a third network node. The monitoring event configuration information comprises the information indicating the event reporting interval and/or the event reporting frequency.

FIG. 22 is a block diagram showing a third network node according to an embodiment of the disclosure. As shown, the third network node 2200 comprises a receiving module 2201. The receiving module 2201 may be configured to receive monitoring event configuration information from a network node. The monitoring event configuration information comprises information indicating event reporting interval and information indicating remain time of the event reporting interval. The event reporting interval indicates a minimal interval to report an event. The third network node further comprises a detecting module 2202 configured to detect a monitoring event related to the monitoring event configuration information. The third network node further comprises a first sending module 2203 configured to send an event notification message comprising the monitoring event to an NEF based on the event reporting interval and the remain time of the event reporting interval..

The term unit or module may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

With function units, the exposure function node, the NEF, the application node, the first network node, the UDM, the second network node, the AMF or the third network node may not need a fixed processor or memory, any computing resource and storage resource may be arranged from the exposure function node, the NEF, the application node, the first network node, the UDM, the second network node, the AMF or the third network node in the communication system. The introduction of virtualization technology and network computing technology may improve the usage efficiency of the network resources and the flexibility of the network.

According to an aspect of the disclosure it is provided a computer program product being tangibly stored on a computer readable storage medium and including instructions which, when executed on at least one processor, cause the at least one processor to carry out any of the methods as described above.

According to an aspect of the disclosure it is provided a computer-readable storage medium storing instructions which when executed by at least one processor, cause the at least one processor to carry out any of the methods as described above.

In addition, the present disclosure may also provide a carrier containing the computer program as mentioned above, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium. The computer readable storage medium can be, for example, an optical compact disk or an electronic memory device like a RAM (random access memory) , a ROM (read only memory) , Flash memory, magnetic tape, CD-ROM, DVD, Blue-ray disc and the like.

The techniques described herein may be implemented by various means so that an apparatus implementing one or more functions of a corresponding apparatus described with an embodiment comprises not only prior art means, but also means for implementing the one or more functions of the corresponding apparatus described with the embodiment and it may comprise separate means for each separate function or means that may be configured to perform one or more functions. For example, these techniques may be implemented in hardware (one or more apparatuses) , firmware (one or more apparatuses) , software (one or more modules) , or combinations thereof. For a firmware or software, implementation may be made through modules (e.g., procedures, functions, and so on) that perform the functions described herein.

Exemplary embodiments herein have been described above with reference to block diagrams and flowchart illustrations of methods and apparatuses. It will be understood that each block of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, respectively, can be implemented by various means including computer program instructions. These computer program instructions may be loaded onto a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create means for implementing the functions specified in the flowchart block or blocks.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the subject matter described herein, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any implementation or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular implementations. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The above described embodiments are given for describing rather than limiting the disclosure, and it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the disclosure as those skilled in the art readily understand. Such modifications and variations are considered to be within the scope of the disclosure and the appended claims. The protection scope of the disclosure is defined by the accompanying claims.

Claims

A method (310) performed by a Network Exposure Function, NEF, comprising:

receiving (312) a first monitoring request from an application node; and

sending (314) a second monitoring request to a Unified Data Management, UDM,

wherein the first monitoring request and/or the second monitoring request comprises information indicating event reporting interval,

wherein the event reporting interval indicates a minimal interval to report an event,

wherein the first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.
The method according to claim 1, wherein the first monitoring request comprises at least one of:

a Monitoring Request message, or

an Nnef_EventExposure_Subscribe request.
The method according to claim 1 or 2, wherein the second monitoring request comprises at least one of:

a Monitoring Request message,

an Nudm_EventExposure_Subscribe request,

an Namf_EventExposure_Subscribe request, or

an Nsmf_EventExposure_Subscribe request.
The method according to any of claims 1-3, wherein the application node comprises at least one of:

Application Servers (AS) ,

Services Capability Server (SCS) , or

Application Function (AF) .
The method according to any of claims 1-4, further comprising:

receiving (302) a first event notification message comprising an event report related to the first monitoring request from a network node; and

sending (304) a second event notification message comprising the event report related to the first monitoring request to the application node.
The method according to claim 5, wherein the first event notification message is sent to the NEF based on the event reporting interval.
The method according to claim 5 or 6, wherein the second event notification message is sent to the application node based on the event reporting interval.
The method according to any of claims 5-7, wherein the network node comprises at least one of:

HSS,

UDM,

MME,

SGSN,

AMF, or

SMF.
The method according to any of claims 5-8, wherein the first event notification message comprises at least one of:

a Monitoring Indication message,

a Monitoring Response message,

an Nudm_EventExposure_Notify message,

an Namf_EventExposure_Notify message, or

an Nsmf_EventExposure_Notify message.
The method according to any of claims 5-9, wherein the second event notification message comprises at least one of:

a Monitoring Indication message,

a Monitoring Response message, or

an Nnef_EventExposure_Notify message.
A method (410) performed by an application node, comprising:

sending (412) a first monitoring request to an NEF; and

receiving (414) a second event notification message from the NEF,

wherein the second event notification message is sent to the application node based on event reporting interval,

wherein the event reporting interval indicates a minimal interval to report an event,

wherein the first monitoring request is used for monitoring user equipment (UE) reachability.
The method according to claim 11, wherein the first monitoring request comprises the information indicating the event reporting interval.
The method according to claim 11 or 12, wherein the first monitoring request comprises at least one of:

a Monitoring Request message, or

an Nnef_EventExposure_Subscribe request.
The method according to any of claims 11-13, wherein the application node comprises at least one of:

Application Servers (AS) ,

Services Capability Server (SCS) , or

Application Function (AF) .
The method according to any of claims 11-14, wherein the second event notification message comprises at least one of:

a Monitoring Indication message,

a Monitoring Response message, or

an Nnef_EventExposure_Notify message.
A method (810) performed by a Unified Data Management, UDM, comprising:

receiving (812) a second monitoring request from an NEF, wherein the second monitoring request is used for monitoring user equipment (UE) reachability and comprises information indicating event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event; and

sending (814) a third monitoring request to an Access and mobility Function, AMF,

wherein the third monitoring request comprises the information indicating the event reporting interval.
The method according to claim 16, wherein the second monitoring request comprises at least one of:

a Monitoring Request message,

an Nudm_EventExposure_Subscribe request,

an Namf_EventExposure_Subscribe request, or

an Nsmf_EventExposure_Subscribe request.
The method according to any of claims 16-17, further comprising:

detecting (604) a monitoring event related to the second monitoring request; and

sending (606) a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.
The method according to claim 18, wherein the first event notification message comprises at least one of:

a Monitoring Indication message,

a Monitoring Response message,

an Nudm_EventExposure_Notify message,

an Namf_EventExposure_Notify message, or

an Nsmf_EventExposure_Notify message.
The method according to any of claims 16-19, wherein the third monitoring request comprises at least one of:

a Monitoring Request message,

an Nudm_EventExposure_Subscribe request,

an Namf_EventExposure_Subscribe request, or

an Nsmf_EventExposure_Subscribe request.
The method according to any of claims 16-20, further comprising:

sending (804) monitoring event configuration information to a third network node,

wherein the monitoring event configuration information comprises the information indicating the event reporting interval.
The method according to claim 21, wherein the monitoring event configuration information is sent during at least one of:

a procedure of UE moving from fifth generation system (5GS) to Evolved Packet System (EPS) ;

a procedure of UE moving from EPS to 5GS;

a registration procedure with a change of Access and mobility Function (AMF) ;

a procedure with SMF change; or

an Inter next generation radio access network (NG-RAN) node N2 based handover procedure with a change of Access and mobility Function (AMF) .
The method according to claim 21 or 22, wherein the monitoring event configuration information further comprises information indicating remain time of the event reporting interval.
A method (1110) performed by an Access and mobility Function, AMF, comprising:

receiving (1112) a third monitoring request for monitoring user equipment (UE) reachability from a Unified Data Management, UDM, wherein the third monitoring request comprises information indicating event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event;

detecting (1114) a monitoring event related to the third monitoring request; and

sending (1116) a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.
The method according to claim 24, wherein the third monitoring request comprises at least one of:

a Monitoring Request message,

an Nudm_EventExposure_Subscribe request,

an Namf_EventExposure_Subscribe request, or

an Nsmf_EventExposure_Subscribe request.
The method according to claim 24 or 25, wherein the first event notification message comprises at least one of:

a Monitoring Indication message,

a Monitoring Response message,

an Nudm_EventExposure_Notify message,

an Namf_EventExposure_Notify message, or

an Nsmf_EventExposure_Notify message.
The method according to any of claims 24-26, further comprising:

sending (1104) monitoring event configuration information to a third network node,

wherein the monitoring event configuration information comprises the information indicating the event reporting interval.
The method according to claim 27, wherein the monitoring event configuration information is sent during at least one of:

a procedure of UE moving from fifth generation system (5GS) to Evolved Packet System (EPS) ;

a procedure of UE moving from EPS to 5GS;

a registration procedure with a change of Access and mobility Function (AMF) ;

a procedure with SMF change; or

an Inter next generation radio access network (NG-RAN) node N2 based handover procedure with a change of Access and mobility Function (AMF) .
The method according to claim 27 or 28, wherein the monitoring event configuration information further comprises information indicating remain time of the event reporting interval.
A method (1410) performed by a third network node, comprising:

receiving (1412) monitoring event configuration information from a network node, wherein the monitoring event configuration information comprises information indicating event reporting interval and information indicating remain time of the event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event;

detecting (1414) a monitoring event related to the monitoring event configuration information; and

sending (1416) an event notification message comprising the monitoring event to an NEF based on the event reporting interval and the remain time of the event reporting interval.
The method according to claim 30, wherein the network node comprises at least one of:

MME,

SGSN,

AMF, or

SMF.
The method according to any of claims 30-31, wherein the third network node comprises at least one of:

MME,

SGSN,

AMF, or

SMF..
The method according to any of claims 30-32, wherein the monitoring event configuration information is received or sent during at least one of:

a procedure of UE moving from fifth generation system (5GS) to Evolved Packet System (EPS) ;

a procedure of UE moving from EPS to 5GS;

a registration procedure with a change of Access and mobility Function (AMF) ;

a procedure with SMF change; or

an Inter next generation radio access network (NG-RAN) node N2 based handover procedure with a change of Access and mobility Function (AMF) .
An NEF (1700) , comprising:

a processor (1721) ; and

a memory (1722) coupled to the processor (1721) , said memory (1722) containing instructions executable by said processor (1721) , whereby said NEF (1700) is operative to:

receive a first monitoring request from an application node; and

send a second monitoring request to a Unified Data Management, UDM,

wherein the first monitoring request and/or the second monitoring request comprises information indicating event reporting interval,

wherein the event reporting interval indicates a minimal interval to report an event,

wherein the first monitoring request and the second monitoring request are used for monitoring user equipment (UE) reachability.
The NEF according to claim 34, wherein the NEF is further operative to perform the method of any one of claims 2 to 10.
An application node (1700) , comprising:

a processor (1721) ; and

a memory (1722) coupled to the processor (1721) , said memory (1722) containing instructions executable by said processor (1721) , whereby said application node (1700) is operative to:

send a first monitoring request to an NEF; and

receive a second event notification message from the NEF,

wherein the second event notification message is sent to the application node based on event reporting interval,

wherein the event reporting interval indicates a minimal interval to report an event,

wherein the first monitoring request is used for monitoring user equipment (UE) reachability.
The application node according to claim 36, wherein the application node is further operative to perform the method of any one of claims 12 to 15.
A Unified Data Management, UDM (1700) , comprising:

a processor (1721) ; and

a memory (1722) coupled to the processor (1721) , said memory (1722) containing instructions executable by said processor (1721) , whereby said UDM (1700) is operative to:

receive a second monitoring request from an NEF, wherein the second monitoring request is used for monitoring user equipment (UE) reachability and comprises information indicating event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event;

send a third monitoring request to an Access and mobility Function, AMF,

wherein the third monitoring request comprises the information indicating the event reporting interval.
The UDM according to claim 38, wherein the UDM is further operative to perform the method of any one of claims 17 to 23.
An Access and mobility Function, AMF (1700) , comprising:

a processor (1721) ; and

a memory (1722) coupled to the processor (1721) , said memory (1722) containing instructions executable by said processor (1721) , whereby said AMF (1700) is operative to:

receive a third monitoring request for monitoring user equipment (UE) reachability from a Unified Data Management, UDM, wherein the third monitoring request comprises information indicating event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event;

detect a monitoring event related to the third monitoring request; and

send a first event notification message comprising the monitoring event to an NEF based on the event reporting interval.
The AMF according to claim 40, wherein the AMF is further operative to perform the method of any one of claims 25 to 29.
A third network node (1700) , comprising:

a processor (1721) ; and

a memory (1722) coupled to the processor (1721) , said memory (1722) containing instructions executable by said processor (1721) , whereby said third network node (1700) is operative to:

receive monitoring event configuration information from a network node, wherein the monitoring event configuration information comprises information indicating event reporting interval and information indicating remain time of the event reporting interval, wherein the event reporting interval indicates a minimal interval to report an event;

detect a monitoring event related to the monitoring event configuration information; and

send an event notification message comprising the monitoring event to an NEF based on the event reporting interval and the remain time of the event reporting interval.
The third network node according to claim 42, wherein the third network node is further operative to perform the method of any one of claims 31 to 33.
A computer-readable storage medium storing instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 33.
A computer program product comprising instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 33.