Method and apparatus for incident reporting

Abstract

A method and apparatus for event reporting are disclosed. According to one embodiment, an access and mobility management function (AMF) entity detects that the state of a terminal device changes from unreachable to reachable, and sends a report indicating that the terminal device is reachable to a first entity. The report includes a maximum availability time during which the terminal device is expected to be reachable.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to communications, and more particularly, to methods and apparatus for event reporting. Background Art

[0002] This section introduces various aspects that may facilitate a better understanding of the present disclosure. Therefore, the statements in this section are to be read in this light, and not to be construed as admissions of what is or is not prior art.

[0003] According to Section 5.31.7 of the 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 23.501V16.2.0, when the Mobile Initiated Connection Only (MICO) mode is used, for example, for Cellular Internet of Things (CIoT), in order to achieve user equipment (UE) energy saving and enhance mobile terminated (MT) reachability, the following features are specified: extended discontinuous reception (DRX) for connection management idle (CM-IDLE) and CM-CONNECTED with radio resource control inactivity (RRC-INACTIVE); MICO mode with extended connection time; MICO mode with active time; and MICO mode and periodic registration timer control.

[0004] The UE and the network may negotiate the use of extended idle mode DRX via non-access stratum (NAS) signaling to reduce its power consumption while being available for MT data and / or network initiated procedures within a certain delay depending on the DRX cycle value. The specific negotiation process is described in 3GPP TS23.502.

[0005] Applications that want to use extended idle mode DRX need to consider the specific handling of mobile terminated services or data transfers, and in particular these applications need to consider the delay tolerance of mobile terminated data. Network-side applications may send mobile terminated data, short message service (SMS) or device triggers, and need to know that extended idle mode DRX may be ready. The UE should request extended idle mode DRX only when all expected mobile terminated communications can tolerate delays.

[0006] For Wideband Evolved Universal Terrestrial Radio Access (WB-E-UTRA) connected to the fifth generation core (5GC), the extended idle mode DRX value range will include values ​​starting from 5.12s (i.e., 5.12s, 10.24s, 20.48s, etc.) up to a maximum value of 2621.44s (nearly 44 minutes). For narrowband IoT (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 value of 10485.76s (nearly 3 hours) (see 3GPP TS 36.304). The extended idle mode DRX cycle length is negotiated via NAS signaling. The access and mobility management function (AMF) includes the extended idle mode DRX cycle length of WB-E-UTRA or NB-IoT in the paging message to assist the next generation radio access network (NG-RAN) node in paging the UE.

[0007] The Hyper System Frame Number (H-SFN) frame structure is defined on top of the SFN used for regular idle mode DRX. Each H-SFN value corresponds to a period of a traditional SFN of 1024 radio frames, i.e. 10.24s. When extended idle mode DRX is enabled for a UE, the UE is reachable in a specific paging superframe (PH) (a paging superframe is a set of specific H-SFN values) for paging. The PH calculation is a formula as a function of the extended idle mode DRX cycle and a UE-specific identifier, as described in TS 36.304. This value can be calculated at all UEs and AMF without signaling. The AMF includes the extended idle mode DRX cycle length and the paging time window (PTW) length in the paging message to assist the NG-RAN node in paging the UE.

[0008] The AMF also allocates a paging time window length and provides this value to the UE together with the extended idle mode DRX cycle length during the registration update procedure. The UE first paging occasion is within the paging superframe, as described in TS 36.304. The UE is assumed to be reachable within the paging time window for paging. The start and end of the paging time window are described in TS 36.304. After the paging time window length, the AMF considers the UE unreachable for paging until the next paging superframe.

[0009] For MICO mode with extended connection time, when a UE using MICO mode initiates mobile origination (MO) signaling or MO data and the AMF knows the pending or expected MT service, the AMF may keep the UE in the CM-CONNECTED state and the RAN may keep the UE in the RRC-CONNECTED state during the extended connection period to ensure that downlink data and / or signaling is delivered to the UE. The extended connection time is determined by the AMF and is based on local configuration and / or maximum response time (if provided by unified data management (UDM)).

[0010] The AMF maintains the N2 connection for at least the extended connection time and provides the extended connection time value to the RAN. The extended connection time value indicates the minimum time the RAN should keep the UE in the RRC-CONNECTED state regardless of inactivity. The extended connection time value is provided to the RAN together with the NAS Registration Accept message or the NAS Service Accept message.

[0011] For MICO mode with active time, the UE may optionally request an active time value from the AMF as part of the MICO mode negotiation during the registration process. In response, if the AMF receives an active time value from the UE and determines that MICO mode is allowed for the UE, the AMF may, for example, assign an active time value to the UE based on local configuration, expected UE behavior (if available), the active time value requested by the UE, UE subscription information, and network policy, and indicate the active time value to the UE during the registration process. When the active time value is assigned to the UE, the AMF shall consider the UE reachable for paging after transitioning from CM-CONNECTED to CM-IDLE within the duration of the active time.

[0012] The UE and AMF shall set a timer corresponding to the Active Time value negotiated during the most recent registration procedure. The UE and AMF shall start the timer when entering the CM-IDLE state from CM-CONNECTED. When the timer expires (i.e., the Active Time is reached), the UE enters MICO mode and the AMF can infer that the UE has entered MICO mode and is not available for paging. If the UE enters the CM-CONNECTED state before the timer expires, the UE and AMF shall stop and reset the timer. If the Active Time value was not negotiated during the most recent registration procedure, the UE will not start the timer, but will enter MICO mode directly after entering the CM-IDLE state.

[0013] For MICO mode and periodic registration timer control, for UEs in MICO mode, if the expected UE behavior indicates that there is no downlink (DL) communication, the AMF may assign a larger periodic registration timer value to the UE to enable the UE to maximize energy saving between periodic registration updates.

[0014] If the expected UE behavior indicates scheduled DL communication, the AMF shall assign a periodic registration timer value so that the UE performs a periodic registration update to renegotiate the MICO mode before or at the scheduled DL communication time. Summary of the invention

[0015] 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.

[0016] One of the objects of the present disclosure is to provide an improved solution for incident reporting.

[0017] According to a first aspect of the present disclosure, a method performed by a network node implementing an access and mobility management function AMF entity is provided. The method may include: detecting that the state of a terminal device changes from unreachable to reachable. The method may also include: sending a report indicating that the terminal device is reachable to a first entity. The report may include the maximum availability time during which the terminal device is expected to be reachable. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for a mobile-initiated-only connection MICO mode; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0018] In this way, the service consumer can use the reported maximum availability time to schedule message delivery to the end device.

[0019] In one embodiment of the present disclosure, the maximum availability time may indicate an absolute time point.

[0020] In one embodiment of the present disclosure, the method may further include: receiving a subscription request for event reports related to the reachability of the terminal device from a second entity. The report may be sent based on the subscription request.

[0021] In one embodiment of the present disclosure, the maximum availability time can be derived by determining the period of time that the terminal device is to remain reachable after the state of the terminal device changes from unreachable to reachable. The maximum availability time can be derived by determining the current time plus the length of the period as the maximum availability time.

[0022] In one embodiment of the present disclosure, the second entity may be one of a network open function NEF entity, a network data analysis function NWDAF entity, a unified data management UDM entity, and a session management function SMF entity.

[0023] In one embodiment of the present disclosure, the first entity may be one of the following: a UDM entity, a network open function NEF entity, an application function AF entity, a short message service SMS entity, a service capability server SCS entity, an application server AS entity, a SMF entity, and a user plane function UPF entity.

[0024] In one embodiment of the present disclosure, the first entity may be one of an AF entity, an SMS entity, an SCS entity, an AS entity, an SMF entity, an UPF entity, and an NEF entity. The maximum availability time may be used by the first entity to prioritize the transmission of messages.

[0025] According to a second aspect of the present disclosure, a method performed by a network node implementing a UDM entity is provided. The method may include: receiving a first report indicating that a terminal device is reachable from an AMF entity. The first report may include the maximum availability time during which the terminal device is expected to be reachable. The method may also include: sending a second report indicating that the terminal device is reachable to a third entity. The second report may include the maximum availability time. The maximum availability time may be derived based on the energy saving configuration of the terminal device. The energy saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for a MICO mode of connection initiated only by mobile; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0026] In this way, the service consumer can use the reported maximum availability time to schedule message delivery to the end device.

[0027] In one embodiment of the present disclosure, the method may also include: in response to a triggering event indicating that the third entity needs an event report related to the reachability of the terminal device, sending a first subscription request for an event report related to the reachability of the terminal device to the AMF entity.

[0028] In one embodiment of the present disclosure, the trigger event may be at least one of the following: receiving a message indicating a failure of SMS delivery to the terminal device from an SMS gateway mobile service switching center SMS-GMSC; and receiving a second subscription request for event reports related to the reachability of the terminal device from an NEF entity.

[0029] In one embodiment of the present disclosure, the third entity may be one of the following: a NEF entity, an AF entity, an SMS entity, an SCS entity, and an AS entity.

[0030] According to a third aspect of the present disclosure, a method performed by a network node implementing an NEF entity is provided. The method may include: receiving a first report indicating that a terminal device is reachable from a UDM entity or an AMF entity. The first report may include the maximum availability time during which the terminal device is expected to be reachable. The method may also include: sending a second report indicating that the terminal device is reachable to a fourth entity. The second report may include the maximum availability time. The maximum availability time may be derived based on the energy saving configuration of the terminal device. The energy saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for a mobile-initiated-only connection MICO mode; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0031] In this way, the service consumer can use the reported maximum availability time to schedule message delivery to the end device.

[0032] In one embodiment of the present disclosure, the method may further include: receiving a first subscription request for event reports related to the reachability of the terminal device from the fourth entity. The method may further include: sending a second subscription request for event reports related to the reachability of the terminal device to the UDM entity.

[0033] In one embodiment of the present disclosure, the fourth entity may be one of the following: an AF entity; an SCS entity; and an AS entity.

[0034] According to a fourth aspect of the present disclosure, a method performed by a network node implementing a service user is provided. The method may include: receiving one or more reports indicating that one or more terminal devices are reachable from a service provider. Each of the one or more reports may contain a maximum availability time during which a terminal device is expected to be reachable. The method may also include: sending one or more messages to the one or more terminal devices based on the maximum availability time of the one or more terminal devices. The maximum availability time may be derived based on a power saving configuration of the terminal device. The power saving configuration of the terminal device may include one or more of the following: at least one parameter related to an extended connection time for a mobile-initiated-only connection MICO mode; at least one parameter related to an active time of a MICO mode; and at least one parameter related to a periodic registration timer control for a MICO mode.

[0035] In this way, the efficiency of message transmission to the terminal device can be improved.

[0036] In one embodiment of the present disclosure, a plurality of reports indicating that a plurality of terminal devices are reachable may be received. The messages may be sent to the plurality of terminal devices by sorting the plurality of messages based on the maximum availability times of the plurality of terminal devices.

[0037] In one embodiment of the present disclosure, the messages may be sorted in ascending order of the maximum availability times of the multiple terminal devices. The messages may be sent to the multiple terminal devices in ascending order of the maximum availability times.

[0038] In one embodiment of the present disclosure, the one or more messages may be SMS messages, or the one or more messages may be used for non-Internet protocol (non-IP) data transfer (NIDD).

[0039] In one embodiment of the present disclosure, the service provider may be one of the following: a UDM entity, a NEF entity, an AMF entity, and a SMF entity.

[0040] In one embodiment of the present disclosure, the service user may be one of the following: an SMS entity, an AF entity, an SCS entity, an AS entity, a NEF entity, an SMF entity, and a UPF entity.

[0041] According to a fifth aspect of the present disclosure, a network node implementing an AMF entity is provided. The AMF entity may include at least one processor and at least one memory. The at least one memory may contain instructions that can be executed by the at least one processor, whereby the AMF entity is operable to detect that the state of a terminal device changes from unreachable to reachable. The AMF entity is also operable to send a report to a first entity indicating that the terminal device is reachable. The report may contain the maximum availability time during which the terminal device is expected to be reachable. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for a MICO mode of connection initiated only by mobile; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0042] In one embodiment of the present disclosure, the AMF entity is operable to perform the method according to the first aspect above.

[0043] According to a sixth aspect of the present disclosure, a network node implementing a UDM entity is provided. The UDM entity may include at least one processor and at least one memory. The at least one memory may contain instructions that can be executed by the at least one processor, whereby the UDM entity is operable to receive a first report indicating that a terminal device is reachable from an AMF entity. The first report may contain the maximum availability time during which the terminal device is expected to be reachable. The UDM entity is also operable to send a second report indicating that the terminal device is reachable to a third entity. The second report may contain the maximum availability time. The maximum availability time may be derived based on the energy saving configuration of the terminal device. The energy saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for a mobile-initiated-only connection MICO mode; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0044] In one embodiment of the present disclosure, the UDM entity is operable to execute the method according to the second aspect above.

[0045] According to a seventh aspect of the present disclosure, a network node implementing a NEF entity is provided. The NEF entity may include at least one processor and at least one memory. The at least one memory may contain instructions executable by the at least one processor, whereby the NEF entity is operable to receive a first report indicating that a terminal device is reachable from a UDM entity or an AMF entity. The first report may contain the maximum availability time during which the terminal device is expected to be reachable. The NEF entity is also operable to send a second report indicating that the terminal device is reachable to a fourth entity. The second report may contain the maximum availability time. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for a mobile-initiated-only connection MICO mode; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0046] In one embodiment of the present disclosure, the NEF entity is operable to execute the method according to the third aspect above.

[0047] According to an eighth aspect of the present disclosure, a network node for implementing a service user is provided. The service user may include at least one processor and at least one memory. The at least one memory may contain instructions that can be executed by the at least one processor, whereby the service user is operable to receive one or more reports from a service provider indicating that one or more terminal devices are reachable. Each of the one or more reports may contain the maximum availability time at which a terminal device is expected to be reachable. The service user is also operable to send one or more messages to the one or more terminal devices based on the maximum availability time of the one or more terminal devices. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for a mobile-initiated-only connection MICO mode; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0048] In one embodiment of the present disclosure, the service user may be operable to execute the method according to the fourth aspect above.

[0049] According to a ninth aspect of the present disclosure, a computer program product is provided, which may include 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 to fourth aspects.

[0050] According to a tenth aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium may include instructions, and when the instructions are executed by at least one processor, the at least one processor executes the method according to any one of the first to fourth aspects.

[0051] According to the eleventh aspect of the present disclosure, a network node implementing an AMF entity is provided. The AMF entity may include: a detection module, which is used to detect that the state of a terminal device has changed from unreachable to reachable. The AMF entity may also include: a sending module, which is used to send a report indicating that the terminal device is reachable to a first entity. The report may contain the maximum availability time during which the terminal device is expected to be reachable. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for the MICO mode of mobile-initiated connections only; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0052] According to the twelfth aspect of the present disclosure, a network node implementing a UDM entity is provided. The UDM entity may include: a receiving module, which is used to receive a first report indicating that a terminal device is reachable from an AMF entity. The first report may include the maximum availability time during which the terminal device is expected to be reachable. The UDM entity may also include: a sending module, which is used to send a second report indicating that the terminal device is reachable to a third entity. The second report may include the maximum availability time. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for the MICO mode of mobile-initiated connections only; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0053] According to the thirteenth aspect of the present disclosure, a network node implementing a NEF entity is provided. The NEF entity may include: a receiving module, which is used to receive a first report indicating that a terminal device is reachable from a UDM entity or an AMF entity. The first report may contain the maximum availability time that the terminal device is expected to be reachable. The NEF entity may also include: a sending module, which is used to send a second report indicating that the terminal device is reachable to a fourth entity. The second report may contain the maximum availability time. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for the MICO mode of mobile-initiated connections only; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode.

[0054] According to the fourteenth aspect of the present disclosure, a network node for implementing a service user is provided. The service user may include: a receiving module, which is used to receive one or more reports indicating that one or more terminal devices are reachable from a service provider. Each of the one or more reports may contain the maximum availability time that the terminal device is expected to be reachable. The service user may also include: a sending module, which is used to send one or more messages to the one or more terminal devices based on the maximum availability time of the one or more terminal devices. The maximum availability time may be derived based on the energy-saving configuration of the terminal device. The energy-saving configuration of the terminal device may include one or more of the following: at least one parameter related to the extended connection time for the MICO mode of mobile-initiated connections only; at least one parameter related to the activity time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] These and other objects, features and advantages of the present disclosure will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.

[0056] Figure 1 is a diagram illustrating an exemplary communication system to which embodiments of the present disclosure may be applied;

[0057] Figure 2 is a flowchart illustrating a method implemented at an AMF entity according to an embodiment of the present disclosure;

[0058] Figure 3 is a flowchart illustrating a method implemented at an AMF entity according to another embodiment of the present disclosure;

[0059] Figure 4 It is used to illustrate Figure 2 A flowchart of the method;

[0060] Figure 5 is a flowchart illustrating a method implemented at a UDM entity according to an embodiment of the present disclosure;

[0061] Figure 6 is a flowchart illustrating a method implemented at a UDM entity according to another embodiment of the present disclosure;

[0062] Figure 7 is a flow chart illustrating a method implemented at a NEF entity according to an embodiment of the present disclosure;

[0063] Figure 8 is a flow chart showing a method implemented at a NEF entity according to another embodiment of the present disclosure;

[0064] Fig. 9 is a flowchart showing a method implemented at a service user according to an embodiment of the present disclosure;

[0065] Figures 10A-10B is a flowchart illustrating an exemplary process according to an embodiment of the present disclosure;

[0066] Figures 11A-11B is a flowchart illustrating an exemplary process according to an embodiment of the present disclosure;

[0067] Figures 12A-12B is a flowchart illustrating an exemplary process according to an embodiment of the present disclosure;

[0068] Fig.13 is a block diagram illustrating an apparatus suitable for implementing some embodiments of the present disclosure;

[0069] Fig.14 is a block diagram illustrating an AMF entity according to an embodiment of the present disclosure;

[0070] Fig.15 is a block diagram illustrating a UDM entity according to an embodiment of the present disclosure;

[0071] Fig.16 is a block diagram illustrating a NEF entity according to an embodiment of the present disclosure; and

[0072] Fig.17 is a block diagram illustrating a service consumer according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0073] For purposes of explanation, details are set forth in the following description in order to provide a thorough understanding of the disclosed embodiments. However, it will be apparent to one skilled in the art that these embodiments can be implemented without these specific details or by an equivalent arrangement.

[0074] When a network function (NF) service consumer (e.g., NEF) needs to create a subscription to monitor at least one event related to AMF, the NF service consumer calls the subscription service operation to AMF. A NF service consumer can subscribe to multiple events in one subscription. A subscription can be associated with one UE, a group of UEs, or any UE. The NF service consumer will request to create a new subscription by using the Hypertext Transfer Protocol (HTTP) method POST with the Uniform Resource Identifier (URI) of the subscription set, see Section 6.2.3.2 of 3GPP TS 29.518 V16.1.1. More details on event subscription to AMF can be obtained from Section 5.3.2.2.2 of TS 29.518.

[0075] When a specific event included in the subscription has occurred, the AMF calls the notification service operation to the notification URI to send a notification. The AMF will send the notification using the HTTP method POST (which uses the notification URI received in the subscription creation (as specified in Section 5.3.2.2.2 of TS 29.518), including, for example, the subscription identifier (ID), the event ID for which the event has occurred, and the notification correlation ID provided by the NF service consumer at the time of event subscription). In addition, the AMF will also call the notification service operation when the AMF changes during the UE mobility process and if the subscription ID changes (i.e., registration process and switching process). Table 6.2.6.2.4-1 and Table 6.2.6.2.5-1 of TS 29.518 show the definitions of the data structures AmfEventNotification and AmfEventReport used for AMF event notifications. More details about AMF event notifications can be obtained from Section 5.3.2.4 of TS 29.518.

[0076] 3GPP TS 29.503 V16.1.0 Figure 5 .5.2.2.2-1 shows a scenario where a NF service consumer sends a request to the UDM to subscribe to event occurrence notifications. The request contains the callback URI, the type of monitored event, and additional information such as event filters and reporting options. More details can be obtained from Section 5.5.2.2.2 of TS 29.503.

[0077] TS 29.503 Figure 5.5.2.4.2-1 shows the scenario where the UDM notifies the NF service consumer (which has subscribed to receive such notifications) of an event occurrence. The request contains the callbackReferenceURI as previously received in the EeSubscription (see section 6.4.6.2.2 of TS 29.503). Table 6.4.6.2.4-1 and Table 6.4.6.2.12-1 of TS29.503 show the definition of the data structures MonitoringReport and ReachabilityForSmsReport used for UDM event notifications. More details can be obtained from section 5.5.2.4.2 of TS 29.503.

[0078] High latency communications can be used to handle MT communications with UEs that are unreachable when using the energy saving functions as described above. "High latency" refers to the initial response time before normal packet exchange is established. That is, the time it takes before the UE wakes up from its energy saving state and responds to the initial downlink packet or signal.

[0079] When the UE is using the energy saving function in CM-IDLE and is not reachable, high latency data communication is supported by extended buffering of downlink data in the AF or user plane function (UPF) or session management function (SMF) or NEF. In addition, when the UE is using the energy saving function and is not reachable, high latency SMS communication is supported by buffering mobile terminated SMS (MT-SMS) in the SMS service center (SMS-SC).

[0080] UE reachability indicates when the UE becomes reachable for sending SMS or downlink data to the UE, which is detected in response to the UE transitioning to CM-CONNECTED mode (for UEs using power saving mode or extended idle mode DRX) or when the UE will become reachable for paging (for UEs using extended idle mode DRX). This monitoring event supports UE reachability for SMS and reachability for data. Only a one-time monitoring request for reachability for SMS is supported.

[0081] For high-latency data communication, AF or UPF or SMF or NEF should serve multiple users. Therefore, the extended buffering of downlink data in AF or UPF or SMF or NEF can be used for multiple UEs. In addition, for high-latency SMS communication, SMS-SC should serve multiple users, so the SMS messages buffered in SMS-SC can be used for multiple UEs.

[0082] However, in the prior art, the UE reachability report described above does not contain information about how long the UE can remain available after waking up before entering sleep mode again. Therefore, if there are multiple SMS messages or extended data buffered for different UEs, it is impossible for the service entity (e.g., SMS-SC for SMS communication, AF or UPF or SMF or NEF for data transmission) to prioritize SMS or data transmission for different UEs. The worst case is that a specific UE will never have a chance to receive a message from the service entity.

[0083] The present disclosure proposes an improved solution for event reporting. Figure 1-17 Describe the solution in detail.

[0084] Figure 1 is a diagram showing an exemplary communication system to which embodiments of the present disclosure may be applied. As shown in the figure, the communication system includes a user equipment (UE), a (radio) access network ((R)AN), a user plane function (UPF), a data network (DN), an authentication server function (AUSF), an access and mobility management function (AMF), a session management function (SMF), a service communication proxy (SCP), a network slice selection function (NSSF), a network open function (NEF), a network repository function (NRF), a policy control function (PCF), a unified data management (UDM) and an application function (AF). The functional description of the above entities is specified in Section 6 of 3GPP TS 23.501 V16.2.0 (the entire contents of which are incorporated herein by reference).

[0085] Note that within the context of the present disclosure, the term 'terminal equipment (or UE)' used herein may also be referred to as, for example, an access terminal, a mobile station, a mobile unit, a user station, etc. It may refer to any (fixed or mobile) end device that can access a wireless communication network and receive services therefrom. As an example and not a limitation, a UE may include a portable computer, an image capture terminal device (e.g., a digital camera), a game terminal device, a music storage and playback device, a mobile phone, a cellular phone, a smart phone, a tablet computer, a wearable device, a personal digital assistant (PDA), an integrated or embedded wireless card, an external plug-in wireless card, etc.

[0086] In the Internet of Things (IoT) scenario, a terminal device (or UE) may refer to a machine or other device that performs monitoring and / or measurement and sends the results of such monitoring and / or measurement to another terminal device (or UE) and / or a network device. In this case, the terminal device (or UE) may be a machine-to-machine (M2M) device, which may be referred to as a machine-type communication (MTC) device in the 3GPP context. Specific examples of such machines or devices may include sensors, metering devices (e.g., power meters), industrial machinery, bicycles, vehicles, or household or personal appliances (e.g., refrigerators, televisions), personal wearable devices (e.g., watches), etc.

[0087] As used herein, the term "communication system" refers to a system that complies with any suitable communication standard, such as first generation (1G), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols and / or any other protocol currently known or developed in the future. In addition, communications between terminal devices and network nodes in a communication system may be performed according to any suitable generation of communication protocols, including but not limited to 1G, 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols and / or any other protocol currently known or developed in the future. In addition, the specific terms used herein do not limit the present disclosure to the communication system associated with the specific terms, but rather, the specific terms may be more generally applied to other communication systems.

[0088] Figure 2 2 is a flow chart showing a method implemented at an AMF entity according to an embodiment of the present disclosure. In box 202, the AMF entity detects that the state of the terminal device changes from unreachable to reachable. Because the AMF entity has a reachability management function, it can detect this state change. In box 204, the AMF entity sends a report to the first entity indicating that the terminal device is reachable. The report contains the maximum availability time at which the terminal device is expected to be reachable. In this way, the service user can use the reported maximum availability time to schedule message transmission to the terminal device.

[0089] As an example, the first entity may be a UDM entity or a NEF entity, which may be indicated as a destination entity in a subscription request received from the UDM entity. As another example, the first entity may be an SMF entity, which may be indicated as a destination entity in a subscription request received from the SMF entity. In the above example, the report may be sent directly to the UDM entity or the NEF entity or the SMF entity. Other examples of the first entity may include, but are not limited to, an AF entity, an SMS entity (e.g., SMS-SC), an SCS entity, an AS entity, and an UPF entity. In this case, the report may be indirectly sent to the AF entity or the SMS entity or the SCS / AS entity via the UDM entity or the NEF entity, or may be indirectly sent to the UPF entity via the SMF entity. Therefore, the maximum availability time may be used by the first entity (e.g., an AF entity, an SMS entity, an SCS / AS entity, an SMF entity, an UPF entity, or an NEF entity) to prioritize the transmission of messages.

[0090] For example, the AMF entity may derive the maximum availability time by executing blocks 408 and 410. In block 408, the AMF entity determines the period of time that the terminal device is to remain reachable after the state of the terminal device changes from unreachable to reachable. For example, the period may be determined based on the energy saving configuration of the terminal device. The energy saving configuration of the terminal device may include, but is not limited to, one or more of the following: at least one parameter related to the extended connection time for the MICO mode; at least one parameter related to the active time of the MICO mode; and at least one parameter related to the periodic registration timer control for the MICO mode. In block 410, the AMF entity determines the current time plus the length of the period as the maximum availability time. The current time may refer to the point in time when the state of the terminal device is detected to have changed from unreachable to reachable. Therefore, the determined maximum availability time may indicate an absolute point in time. The maximum availability time may also be represented in any other suitable form.

[0091] Figure 3is a flowchart showing a method implemented at an AMF entity according to another embodiment of the present disclosure. In box 301, the AMF entity receives a subscription request for event reports related to the reachability of a terminal device from a second entity. For example, the second entity may be a UDM entity or an SMF entity. The subscription request may include an identifier of the terminal device and also indicate the destination entity to which the report is to be sent. In box 202, the AMF entity detects that the state of the terminal device changes from unreachable to reachable. In box 204, the AMF entity sends a report indicating that the terminal device is reachable to the first entity. The report contains the maximum availability time that the terminal device is expected to be reachable. As described above, the first entity may be the destination entity indicated in the subscription request. Alternatively, the first entity may be another entity that receives the report indirectly via the destination entity. Other details about boxes 202-204 have been described above and are therefore omitted here.

[0092] Figure 5 is a flow chart showing a method implemented at a UDM entity according to an embodiment of the present disclosure. In box 502, the UDM entity receives a first report from an AMF entity indicating that a terminal device is reachable. The first report contains the maximum availability time that the terminal device is expected to be reachable. Box 502 corresponds to box 204. In box 504, the UDM entity sends a second report to a third entity indicating that the terminal device is reachable. The second report contains the maximum availability time. In this way, the service user can use the reported maximum availability time to schedule message transmission to the terminal device.

[0093] As an example, the third entity may be an SMS entity (e.g., SMS Interworking Mobile Service Switching Center, referred to as SMS-IWMSC) or a NEF entity. In this case, the second report may be sent directly to the SMS entity or the NEF entity. Other examples of the third entity may include, but are not limited to, an AF entity, another SMS entity (e.g., SMS-SC), an SCS entity, and an AS entity. In this case, the second report may be sent indirectly to such an entity via the SMS entity or the NEF entity.

[0094] Figure 6is a flowchart illustrating a method implemented at a UDM entity according to another embodiment of the present disclosure. In box 601, in response to a trigger event indicating that a third entity needs an event report related to the reachability of a terminal device, the UDM entity sends a first subscription request for an event report related to the reachability of a terminal device to an AMF entity. As an example, the trigger event may be a message received from an SMS-GMSC indicating a failure in SMS delivery to a terminal device, which means that an event report is required by the SMS-SC. As another example, the trigger event may be a second subscription request for an event report related to the reachability of a terminal device received from an NEF entity. In box 502, the UDM entity receives a first report from an AMF entity indicating that the terminal device is reachable. The first report contains the maximum availability time that the terminal device is expected to be reachable. In box 504, the UDM entity sends a second report to the third entity indicating that the terminal device is reachable. The second report contains the maximum availability time.

[0095] Figure 7 702 is a flowchart showing a method implemented at a NEF entity according to an embodiment of the present disclosure. In block 702, the NEF entity receives a first report from a UDM entity or an AMF entity indicating that a terminal device is reachable. The first report contains a maximum availability time during which the terminal device is expected to be reachable. Block 702 corresponds to block 202 or 504. In block 704, the UDM entity sends a second report to a fourth entity indicating that the terminal device is reachable. The second report contains the maximum availability time. Examples of the fourth entity may include, but are not limited to, an AF entity, an SCS entity, and an AS entity. Figure 7 The method enables a service consumer to use the reported maximum availability time to schedule message delivery to a terminal device.

[0096] Figure 8 8 is a flowchart illustrating a method implemented at a NEF entity according to another embodiment of the present disclosure. In box 801, the NEF entity receives a first subscription request for event reports related to the reachability of a terminal device from a fourth entity. Examples of the fourth entity may include, but are not limited to, an AF entity, an SCS entity, and an AS entity. In box 803, the NEF entity sends a second subscription request for event reports related to the reachability of a terminal device to a UDM entity. In box 702, the NEF entity receives a first report from a UDM entity or an AMF entity indicating that the terminal device is reachable. The first report contains the maximum availability time that the terminal device is expected to be reachable. In box 704, the UDM entity sends a second report to the fourth entity indicating that the terminal device is reachable. The second report contains the maximum availability time.

[0097] Fig. 9902 is a flowchart showing a method implemented at a service user according to an embodiment of the present disclosure. Examples of service users may include, but are not limited to, SMS entities (e.g., SMS-SC), AF entities, SCS entities, AS entities, NEF entities, SMF entities, and UPF entities. For example, a NEF entity may act as a service user on behalf of an AF entity or an SCS / AS entity. An SMF entity may subscribe to event reports from an AMF entity. A UPF entity may subscribe to event reports from an SMF entity. In block 902, a service user receives one or more reports indicating that one or more terminal devices are reachable from a service provider. Each of the one or more reports contains the maximum availability time that the terminal device is expected to be reachable. Examples of service providers may include, but are not limited to, UDM entities, NEF entities, AMF entities, and SMF entities. Depending on the number of reports received within a predetermined period, there may be two situations. In the first case, within a predetermined period, a service user receives a report indicating that a terminal device is reachable. The report contains the maximum availability time of the terminal device. In the second case, within a predetermined period, a service user receives multiple reports indicating that multiple terminal devices are reachable. Each report contains the maximum availability time of the corresponding terminal device.

[0098] In block 904, the service user sends one or more messages to one or more terminal devices based on the maximum availability time of the one or more terminal devices. For example, the one or more messages may be SMS messages, or may be used for non-IP data transmission (NIDD). In the first case described above, because the maximum availability time of the terminal device is known, the service user may send one or more messages to the terminal device as needed as long as time permits. In the second case described above, the service user may send multiple messages to multiple terminal devices by sorting the messages based on the maximum availability time of the multiple terminal devices. For example, the messages may be sorted in ascending order of the maximum availability time of the multiple terminal devices. Accordingly, the messages may be sent to the multiple terminal devices in ascending order of the maximum availability time.

[0099] Figures 10A-10B is a flow chart showing an exemplary process according to an embodiment of the present disclosure. The process involves MT-SMS transmission and is applicable to UEs operating under energy-saving enhancements as described above (in power saving mode (PSM)). As shown in the figure, the process involves multiple UEs (e.g., UE1, UE2, ..., UEn), (R)AN, AMF, SMS function (SMSF), UDM, SMS-IWMSC, SMS-GMSC and SMS-SC. Assume that the UE happens to be in a dormant state when the SMS-SC attempts to transmit an MT-SMS to the user.

[0100] In step 1, multiple UEs (especially based on cellular IoT) are working in an energy-saving enhanced mode (e.g., PSM mode). Assume that at this time, a series of UEs (UE1, UE2, ..., UEn) are in a dormant state. Their subscription permanent identifiers (SUPI) and general public user identifiers (GPSI) are represented as SUPI1, SUPI2, ..., SUPIn and GPSI1, GPSI2, ..., GPSIn, respectively.

[0101] In step 2, a short message needs to be delivered to UE1 as the recipient. SMS-SC initiates the MT-SMS delivery process with the help of SMS on 5GNAS to deliver the short message to UE1 through SMSF and AMF. In step 3, AMF detects that UE1 is sleeping, so it sends an SMS delivery report back to SMS-SC through SMSF and SMS-GMSC, which has a failure indication that the SMS delivery failed, and the failure reason is the lack of user. In step 4, after receiving the SMS delivery report with the failure indication and the failure reason indication, SMS-GMSC also reports the SMS delivery status to UDM, which has a failure indication and the failure reason is the lack of user.

[0102] In step 5, UDM subscribes to AMF for UE reachability for SMS event reporting via Namf_EventExposure_Subscribe request. The message also contains the UE identity, i.e., SUPI of UE1 (indicated as SUPI1 in the figure). In step 6, AMF accepts the event subscription request and responds to UDM.

[0103] Steps 7-11 described below are a repetitive process of steps 2-6, but for MT-SMS delivery to UE2 / SUPI2. In step 7, a short message needs to be delivered to UE2 as the recipient. SMS-SC initiates the MT-SMS delivery process with the help of SMS over 5G NAS to deliver the short message to UE2 through SMSF and AMF. In step 8, AMF detects that UE2 is sleeping, so it sends an SMS delivery report back to SMS-SC through SMSF and SMS-GMSC, with a failure indication that the SMS delivery failed and the reason is the lack of user. In step 9, after receiving the SMS delivery report with the failure indication and the failure cause indication, SMS-GMSC also reports the SMS delivery status to UDM, with the failure indication and the reason is the lack of user. In step 10, UDM subscribes to AMF for UE reachability for SMS event reporting through Namf_EventExposure_Subscribe request. The message also contains the UE identity, that is, the SUPI of UE2 (represented as SUPI2 in the figure). In step 11, the AMF accepts the event subscription request and responds to the UDM.

[0104] Steps 12-16 described below are a repetitive process of steps 2-6, but for MT-SMS delivery to UEn / SUPIn. In step 12, a short message needs to be delivered to UEn as the recipient. SMS-SC initiates the MT-SMS delivery process with the help of SMS on 5G NAS to deliver the short message to UEn through SMSF and AMF. In step 13, AMF detects that UEn is dormant, so it sends an SMS delivery report back to SMS-SC through SMSF and SMS-GMSC, which has a failure indication that the SMS delivery failed, and the reason for the failure is the lack of a user. In step 14, after receiving the SMS delivery report with a failure indication and a failure reason indication, SMS-GMSC also reports the SMS delivery status to UDM, which has a failure indication and the reason for the failure is the lack of a user. In step 15, UDM subscribes to AMF for UE reachability for SMS event reporting through a Namf_EventExposure_Subscribe request. The message also contains the UE identity, that is, the SUPI of UEn (represented as SUPIn in the figure). In step 16, the AMF accepts the event subscription request and responds to the UDM.

[0105] In step 17, UE1 wakes up from sleep and contacts the network for pending messages. In step 18, AMF notifies UDM via Namf_EventExposure_Notify interface that UE1 is reachable for SMS, and the maximum availability time for which the UE will remain active, for example 30 seconds. In order to provide the maximum availability time, event reporting with maximum UE availability time may require standardized updates. Table 1 below shows the updated messages exchanged between AMF and UDM to provide the maximum availability time.

[0106] Table 1: Definition of type AmfEventReport (updates compared to Table 6.2.6.2.5-1 of TS 29.518 are underlined)

[0107]

[0108]

[0109] In step 19, when receiving the reachability notification from AMF, UDM reminds SMS-SC to also deliver the pending SMS with the maximum UE availability time. In step 20, SMS-SC triggers MT-SMS delivery. Because the maximum UE availability time is available, SMS-SC can have an enhanced scheduling mechanism, such as keeping a little time instead of delivering MT-SMS immediately.

[0110] In step 21, UE2 wakes up from sleep and contacts the network for pending messages. In step 22, the AMF notifies the UDM via the Namf_EventExposure_Notify interface that UE2 is reachable for SMS, as well as the maximum availability time, e.g. 10 seconds, for which the UE will remain active. The update as described in step 18 is used to provide the maximum availability time in the event report. In step 23, upon receiving the reachability notification from the AMF, the UDM reminds the SMS-SC to also transmit the pending SMS with the maximum availability time. In step 24, the SMS-SC triggers a MT-SMS retransmission. Because the maximum availability time is available, the SMS-SC can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting the MT-SMS immediately.

[0111] In step 25, UEn wakes up from sleep and contacts the network for pending messages. In step 26, AMF notifies UDM via the Namf_EventExposure_Notify interface that UEn is reachable for SMS, as well as the maximum availability time, e.g. 1 minute, for which the UE will remain active. Use the update as described in step 18 to provide the maximum availability time in the event report. In step 27, upon receiving the reachability notification from AMF, UDM reminds SMS-SC to also transmit pending SMS at the maximum availability time. In step 28, SMS-SC triggers MT-SMS retransmission. Because the maximum availability time is available, SMS-SC can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting the MT-SMS immediately.

[0112] In step 29, SMS-SC prioritizes the delivery of SMS in the order in which the UE availability times are to expire based on the maximum availability time. For example, assume that the reminder messages are received at almost the same time. Then, MT-SMS to UE2 takes precedence over MT-SMS to UE1 because UE2 will remain awake for a shorter period than UE1. Similarly, MT-SMS to UE1 takes precedence over MT-SMS to UEn because UE1 will remain awake for a shorter period than UEn. In step 30, MT-SMS delivery to UE2 is successful. In step 31, MT-SMS delivery to UE1 is successful. In step 32, MT-SMS delivery to UEn is successful.

[0113] Steps 29-32 show the optimized MT-SMS delivery schedule to ensure message delivery efficiency. Without the above update, SMS-SC cannot prioritize MT-SMS delivery based on the maximum availability time. If UE2 enters sleep mode again before SMS-SC schedules SMS delivery to UE2, MT-SMS to UE2 is more likely to fail again.

[0114] Figures 11A-11B is a flow chart showing an exemplary process according to an embodiment of the present disclosure. The process involves NIDD data transmission and is applicable to UEs operating under energy saving enhancement (in PSM mode) as described above. As shown in the figure, the process involves multiple UEs (e.g., UE1, UE2, ..., UEn), (R)AN, AMF, SMF, UDM, NEF and AF. Assume that the UE happens to be in a dormant state when the AF attempts to transmit NIDD data to the user.

[0115] In step 1, multiple UEs (especially based on cellular IoT) are working in an energy-saving enhanced mode (e.g., PSM mode). Assume that at this time, a series of UEs (UE1, UE2, ..., UEn) are in a dormant state. Their SUPI and GPSI are represented as SUPI1, SUPI2, ..., SUPIn and GPSI1, GPSI2, ..., GPSIn respectively.

[0116] In step 2, the application service to which UE1 has subscribed has NIDD data to be delivered to UE1 as the recipient. AF triggers the NIDD data delivery process to UE1 through NEF, SMF and AMF through IoT NIDD data delivery optimized by the control plane (CP). In step 3, AMF detects that UE1 is in sleep mode and is unreachable for data delivery, and sends a failure report back to AF through SMF and NEF, which has a failure indication that NIDD data delivery failed, and the failure reason is the lack of user.

[0117] In step 4, after receiving the NIDD data transmission report with a failure indication and a failure cause indication (missing user), the AF subscribes to the UE reachability for DATA event reporting from the NEF through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE1 (represented as SUPI1 / GPSI1 in the figure). The NEF subscribes to the UE reachability for DATA reporting from the UDM through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE1 (represented as SUPI1 / GPSI1 in the figure). The UDM subscribes to the UE reachability for DATA reporting from the AMF through a Namf_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE1 (represented as SUPI1 / GPSI1 in the figure). In step 5, the AMF / UDM / NEF accepts the event subscription request and responds to the UDM / NEF / AF accordingly.

[0118] Steps 6-9 described below are a repetitive process of steps 2-5, but for NIDD data delivery to UE2. In step 6, the application service to which UE2 has subscribed has NIDD data to be delivered to UE2 as the recipient. The AF triggers the NIDD data delivery process to UE2 through NEF, SMF and AMF through CP optimized IoT NIDD data delivery. In step 7, AMF detects that UE2 is in sleep mode and is unreachable for data delivery, and sends a failure report back to AF through SMF and NEF, which has a failure indication that the NIDD data delivery failed, and the failure reason is the lack of user.

[0119] In step 8, after receiving the NIDD data transmission report with a failure indication and a failure cause indication (missing user), the AF subscribes to the UE reachability for DATA event reporting from the NEF through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE2 (represented as SUPI2 / GPSI2 in the figure). The NEF subscribes to the UE reachability for DATA event reporting from the UDM through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE2 (represented as SUPI2 / GPSI2 in the figure). The UDM subscribes to the UE reachability for DATA reporting from the AMF through a Namf_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE2 (represented as SUPI2 / GPSI2 in the figure). In step 9, the AMF / UDM / NEF accepts the event subscription request and responds to the UDM / NEF / AF accordingly.

[0120] Steps 10-13 described below are a repetitive process of steps 2-5, but for NIDD data delivery to UEn. In step 10, the application service to which UEn has subscribed has NIDD data to be delivered to UEn as the recipient. The AF triggers the NIDD data delivery process to UEn through NEF, SMF and AMF through CP optimized IoT NIDD data delivery. In step 11, AMF detects that UEn is in sleep mode and is unreachable for data delivery, and sends a failure report back to AF through SMF and NEF, which has a failure indication that the NIDD data delivery failed, and the failure reason is the lack of user.

[0121] In step 12, after receiving the NIDD data transmission report with a failure indication and a failure cause indication (missing user), the AF subscribes to the UE reachability for DATA event reporting from the NEF through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UEn (represented as SUPIn / GPSIn in the figure). The NEF subscribes to the UE reachability for DATA event reporting from the UDM through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UEn (represented as SUPIn / GPSIn in the figure). The UDM subscribes to the UE reachability for DATA reporting from the AMF through a Namf_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UEn (represented as SUPIn / GPSIn in the figure). In step 13, the AMF / UDM / NEF accepts the event subscription request and responds to the UDM / NEF / AF accordingly.

[0122] In step 14, UE1 wakes up from sleep and contacts the network for pending messages. In step 15, AMF notifies NEF via Namf_EventExposure_Notify interface and NEF notifies AF via Nnef_EventExposure_Notify interface that UE1 is reachable for DATA and the maximum availability time that UE will remain active, e.g. 30 seconds. Fig. 10B The update described in step 18 of is used to provide the maximum availability time in the event report from AMF to NEF. In step 16, AF triggers NIDD data transmission. Because the maximum availability time is available, AF can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting NIDD data immediately.

[0123] In step 17, UE2 wakes up from sleep and contacts the network for pending messages. In step 18, AMF notifies NEF via Namf_EventExposure_Notify interface and NEF notifies AF via Nnef_EventExposure_Notify interface that UE2 is reachable for DATA, and notifies the maximum availability time that UE will remain active, for example 10 seconds. Fig. 10B The update described in step 18 of is used to provide the maximum availability time in the event report from AMF to NEF. In step 19, AF triggers NIDD data transmission. Because the maximum availability time is available, AF can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting NIDD data immediately.

[0124] In step 20, UEn wakes up from sleep and contacts the network for pending messages. In step 21, AMF notifies NEF via Namf_EventExposure_Notify interface and NEF notifies AF via Nnef_EventExposure_Notify interface that UEn is reachable for DATA and the maximum availability time that UE will remain active, for example 1 minute. Fig. 10B The update described in step 18 of is used to provide the maximum availability time in the event report from AMF to NEF. In step 22, AF triggers NIDD data transmission. Because the maximum availability time is available, AF can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting NIDD data immediately.

[0125] In step 23, the AF prioritizes the transmission of data based on the maximum UE availability time in the order in which the availability time is to expire. For example, assume that the reachability for data event reporting is received almost simultaneously. Then, NIDD data to UE2 takes precedence over NIDD data to UE1 because UE2 will remain awake for a shorter period than UE1. Similarly, NIDD data to UE1 takes precedence over NIDD data to UEn because UE1 will remain awake for a shorter period than UEn. In step 24, the NIDD data to UE2 is successfully transmitted. In step 25, the NIDD data to UE1 is successfully transmitted. In step 26, the NIDD data to UEn is successfully transmitted.

[0126] Steps 23-26 show the optimized NIDD data transmission scheduling to ensure data transmission efficiency. Without the above update, the AF cannot prioritize the NIDD data transmission based on the maximum availability time. If UE2 enters sleep mode again before the AF schedules the NIDD data transmission to UE2, the NIDD data transmission to UE2 is more likely to fail again.

[0127] In the above process, for high-delay data communication, AF (or UPF or SMF or NEF) prioritizes and optimizes the transmission of pending messages or data to UEs using energy-saving mechanisms. Because it is known that the UE has a maximum UE availability time (Maximum UE Availability Time), such a parameter can be used as an input to optimize the scheduling mechanism at the service entity.

[0128] Figures 12A-12Bis a flow chart showing an exemplary process according to an embodiment of the present disclosure. The process involves application trigger transmission and is applicable to UEs operating under energy saving enhancement (in PSM mode) as described above. As shown in the figure, the process involves multiple UEs (e.g., UE1, UE2, ..., UEn), (R)AN, AMF, SMSF, UDM, SMS-IWMSC, SMS-GMSC, SMS-SC, NEF and AF. Assume that the UE happens to be in a dormant state when the AF attempts to transmit an application trigger to the user.

[0129] In step 1, multiple UEs (especially based on cellular IoT) are working in an energy-saving enhanced mode (e.g., PSM mode). Assume that at this time, a series of UEs (UE1, UE2, ..., UEn) are in a dormant state. Their SUPI and GPSI are represented as SUPI1, SUPI2, ..., SUPIn and GPSI1, GPSI2, ..., GPSIn respectively.

[0130] In step 2, the application service to which the UE has subscribed has an application trigger message to be delivered to UE1 as the recipient. The AF triggers the application trigger delivery process to UE1 through NEF, SMS-SC and AMF via SMS over NAS. In step 3, the AMF detects that UE1 is in sleep mode and is unreachable for message delivery, and sends a failure report back to the AF via SMS-SC and NEF, with a failure indication that the application trigger delivery failed and the failure reason is the lack of user.

[0131] In step 4, after receiving the message delivery report with a failure indication and a failure cause indication (missing user), the AF subscribes to the UE reachability for SMS event reporting from the NEF through a Nudm_EventExposure_Subscribe request. The message also includes the UE identity, that is, the SUPI / GPSI of UE1 (represented as SUPI1 / GPSI1 in the figure). The NEF subscribes to the UE reachability for SMS event reporting from the UDM through a Nudm_EventExposure_Subscribe request. The message also includes the UE identity, that is, the SUPI / GPSI of UE1 (represented as SUPI1 / GPSI1 in the figure). The UDM subscribes to the UE reachability for SMS event reporting from the AMF through a Namf_EventExposure_Subscribe request. The message also includes the UE identity, that is, the SUPI / GPSI of UE1 (represented as SUPI1 / GPSI1 in the figure). In step 5, the AMF / UDM / NEF accepts the event subscription request and responds to the UDM / NEF / AF accordingly.

[0132] Steps 6-9 described below are a repetitive process of steps 2-5, but for application trigger delivery to UE2. In step 6, the application service to which UE2 has subscribed has an application trigger message to be delivered to UE2 as the recipient. The AF triggers the application trigger delivery process to UE2 through NEF, SMS-SC and AMF via SMS over NAS. In step 7, the AMF detects that UE2 is in sleep mode and is unreachable for data delivery, and sends a failure report back to the AF via SMS-SC and NEF, with a failure indication that the application trigger delivery failed and the failure reason is the lack of user.

[0133] In step 8, after receiving the message delivery report with a failure indication and a failure cause indication (missing user), the AF subscribes to the UE reachability for SMS event reporting from the NEF through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE2 (represented as SUPI2 / GPSI2 in the figure). The NEF subscribes to the UE reachability for SMS event reporting from the UDM through a Nudm_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE2 (represented as SUPI2 / GPSI2 in the figure). The UDM subscribes to the UE reachability for SMS event reporting from the AMF through a Namf_EventExposure_Subscribe request. The message also includes the UE identifier, that is, the SUPI / GPSI of UE2 (represented as SUPI2 / GPSI2 in the figure). In step 9, the AMF / UDM / NEF accepts the event subscription request and responds to the UDM / NEF / AF accordingly.

[0134] Steps 10-13 described below are a repetitive process of steps 2-5, but for application trigger delivery to UEn. In step 10, the application service to which UEn has subscribed has an application trigger message to be delivered to UEn as the recipient. The AF triggers the application trigger delivery process to UEn through NEF, SMS-SC and AMF via SMS on NAS. In step 11, the AMF detects that UEn is in sleep mode and is unreachable for data delivery, and sends a failure report back to the AF via SMS-SC and NEF, with a failure indication that the application trigger delivery failed and the failure reason is the lack of user.

[0135] In step 12, after receiving the message delivery report with a failure indication and a failure cause indication (missing user), the AF subscribes to the UE reachability for SMS reporting from the NEF through a Nudm_EventExposure_Subscribe request. The message also includes the UE identity, that is, the SUPI / GPSI of UEn (represented as SUPIn / GPSIn in the figure). The NEF subscribes to the UE reachability for SMS reporting from the UDM through a Nudm_EventExposure_Subscribe request. The message also includes the UE identity, that is, the SUPI / GPSI of UEn (represented as SUPIn / GPSIn in the figure). The UDM subscribes to the UE reachability for SMS reporting from the AMF through a Namf_EventExposure_Subscribe request. The message also includes the UE identity, that is, the SUPI / GPSI of UEn (represented as SUPIn / GPSIn in the figure). In step 13, the AMF / UDM / NEF accepts the event subscription request and responds to the UDM / NEF / AF accordingly.

[0136] In step 14, UE1 wakes up from sleep and contacts the network for pending messages. In step 15, AMF notifies UDM via Namf_EventExposure_Notify interface, UDM notifies NEF via Nudm_EventExposure_Notify interface, and NEF notifies AF via Nnef_EventExposure_Notify interface that UE1 is reachable for SMS, and the maximum availability time that UE will remain active, for example 30 seconds. Fig. 10B The update described in step 18 is used to provide the maximum availability time in the event report from the AMF to the NEF.

[0137] Table 2 shows an alternative update for event reporting from UDM to NEF to provide maximum UE availability time.

[0138] Table 2: Definition of type ReachabilityForSmsReport (updates compared to Table 6.4.6.2.12-1 of TS 29.503 are underlined)

[0139]

[0140] Table 3 below shows another alternative update for UDM to provide the maximum UE availability time to the NEF.

[0141] Table 3: Definition of type MonitoringReport (updates compared to Table 6.4.6.2.4-1 of TS 29.503 are underlined)

[0142]

[0143] In step 16, the AF triggers the NIDD data transmission. Because the maximum availability time is available, the AF can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting the NIDD data immediately. In step 17, UE2 wakes up from sleep and contacts the network for pending messages. In step 18, the AMF notifies the UDM through the Namf_EventExposure_Notify interface, the UDM notifies the NEF through the Nudm_EventExposure_Notify interface, and the NEF notifies the AF through the Nnef_EventExposure_Notify interface that UE2 is reachable for DATA, and notifies the maximum availability time that the UE will remain active, such as 10 seconds. In step 19, the UE2 is awakened from sleep and contacts the network for pending messages. In step 20, the AMF notifies the UDM through the Namf_EventExposure_Notify interface, the UDM notifies the NEF through the Nudm_EventExposure_Notify interface, and the NEF notifies the AF through the Nnef_EventExposure_Notify interface that the UE2 is reachable for DATA. Fig. 10B The update described in step 18 of is used to provide the maximum availability time in the event report from the AMF to the UDM. Fig. 12B The update described in step 15 of is used to provide the maximum availability time in the event report from the UDM to the NEF. In step 19, the AF triggers the NIDD data transmission. Because the maximum availability time is available, the AF can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting the NIDD data immediately.

[0144] In step 20, UEn wakes up from sleep and contacts the network for pending messages. In step 21, AMF notifies UDM via Namf_EventExposure_Notify interface, UDM notifies NEF via Nudm_EventExposure_Notify interface, and NEF notifies AF via Nnef_EventExposure_Notify interface that UEn is reachable for DATA, and notifies the maximum availability time that UE will remain active, for example 1 minute. Fig. 10B The update described in step 18 of is used to include the maximum availability time in the event report from the AMF to the UDM. Fig. 12B The update described in step 15 of is used to provide the maximum availability time in the event report from the UDM to the NEF. In step 22, the AF triggers the NIDD data transmission. Because the maximum availability time is available, the AF can have an enhanced scheduling mechanism, such as keeping a little time instead of transmitting the NIDD data immediately.

[0145] In step 23, the AF prioritizes the transmission of application triggers based on the maximum availability time in the order in which the availability time is to expire. For example, assume that the reachability for SMS event reporting is received almost simultaneously. Then, the application trigger to UE2 takes precedence over the application trigger to UE1 because UE2 will remain awake for a shorter period than UE1. Similarly, the application trigger to UE1 takes precedence over the application trigger to UEn because UE1 will remain awake for a shorter period than UEn. In step 24, the application trigger transmission to UE2 is successful. In step 25, the application trigger transmission to UE1 is successful. In step 26, the application trigger transmission to UEn is successful.

[0146] Steps 23-26 show the optimized application trigger transmission scheduling to ensure data transmission efficiency. Without the above update, AF cannot prioritize application trigger transmission based on maximum availability time. If UE2 enters sleep mode again before AF schedules application trigger transmission to UE2, the application trigger to UE2 is more likely to fail again.

[0147] exist Figures 10A-10B In the above process shown in Figures 12A-12B, for high-latency SMS communications, SMS-SC or AF prioritizes and optimizes the transmission of pending mobile terminated short messages or application triggers to UEs using energy saving mechanisms. Because the UE is known to have a maximum UE availability time, such a parameter can be used as an input to optimize the scheduling mechanism at the service entity.

[0148] Fig.13 1 is a block diagram showing an apparatus suitable for implementing some embodiments of the present disclosure. For example, any of the above-mentioned AMF entity, UDM entity, NEF entity, and service user can be implemented by the apparatus 1300. As shown in the figure, the apparatus 1300 may include a processor 1310, a memory 1320 storing a program, and an optional communication interface 1330, and the communication interface 1330 is used to transmit data with other external devices through wired and / or wireless communication.

[0149] The program includes program instructions that, when executed by the processor 1310, enable the device 1300 to operate according to the embodiments of the present disclosure as described above. That is, the embodiments of the present disclosure may be implemented at least in part by computer software executable by the processor 1310, or by hardware, or by a combination of software and hardware.

[0150] The memory 1320 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based storage devices, flash memory, magnetic storage devices and systems, optical storage devices and systems, fixed memory, and removable memory. The processor 1310 may be of any type suitable for the local technical environment and may include, as non-limiting examples, one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture.

[0151] Fig.14 14 is a block diagram illustrating an AMF entity according to an embodiment of the present disclosure. As shown, the AMF entity 1400 includes a detection module 1402 and a sending module 1404. The detection module 1402 may be configured to detect that the state of the terminal device changes from unreachable to reachable, as described above for block 202. The sending module 1404 may be configured to send a report indicating that the terminal device is reachable to the first entity, as described above for block 204. The report may include a maximum availability time at which the terminal device is expected to be reachable.

[0152] Fig.15 15 is a block diagram illustrating a UDM entity according to an embodiment of the present disclosure. As shown in the figure, the UDM entity 1500 includes a receiving module 1502 and a sending module 1504. The receiving module 1502 may be configured to receive a first report indicating that a terminal device is reachable from an AMF entity, as described above for block 502. The first report may include a maximum availability time during which the terminal device is expected to be reachable. The sending module 1504 may be configured to send a second report indicating that the terminal device is reachable to a third entity, as described above for block 504. The second report may include the maximum availability time.

[0153] Fig.16 1 is a block diagram illustrating an NEF entity according to an embodiment of the present disclosure. As shown in the figure, the NEF entity 1600 includes a receiving module 1602 and a sending module 1604. The receiving module 1602 may be configured to receive a first report indicating that a terminal device is reachable from a UDM entity or an AMF entity, as described above for block 702. The first report may include a maximum availability time at which the terminal device is expected to be reachable. The sending module 1604 may be configured to send a second report indicating that the terminal device is reachable to a fourth entity, as described above for block 704. The second report may include the maximum availability time.

[0154] Fig.1717 is a block diagram illustrating a service user according to an embodiment of the present disclosure. As shown in the figure, the service user 1700 includes a receiving module 1702 and a sending module 1704. The receiving module 1702 can be configured to receive one or more reports indicating that one or more terminal devices are reachable from the service provider, as described above for box 902. Each of the one or more reports can contain the maximum availability time at which the terminal device is expected to be reachable. The sending module 1704 can be configured to send one or more messages to one or more terminal devices based on the maximum availability time of the one or more terminal devices, as described above for box 904. The above modules can be implemented by hardware or software or a combination of both.

[0155] In general, various exemplary embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device, although the present disclosure is not limited thereto. Although various aspects of the exemplary embodiments of the present disclosure may be shown and described as block diagrams, flow charts, or using some other graphical representation, it will be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0156] Therefore, it should be understood that at least some aspects of the exemplary embodiments of the present disclosure may be implemented in various components (e.g., integrated circuit chips and modules). Therefore, it should be understood that the exemplary embodiments of the present disclosure may be implemented in a device embodied as an integrated circuit, wherein the integrated circuit may include circuits (and possible firmware) for embodying at least one or more of the following: a data processor, a digital signal processor, a baseband circuit, and a radio frequency circuit, which are configurable to operate according to the exemplary embodiments of the present disclosure.

[0157] It should be understood that at least some aspects of the exemplary embodiments of the present disclosure may be embodied in computer executable instructions (e.g., one or more program modules) executed by one or more computers or other devices. Typically, program modules include routines, programs, target programs, components, data structures, etc., which perform specific tasks or implement specific abstract data types when executed by a processor in a computer or other device. Computer executable instructions may be stored on a computer readable medium (e.g., a hard disk, an optical disk, a removable storage medium, a solid-state memory, a RAM, etc.). As will be appreciated by those skilled in the art, in various embodiments, the functions of the program modules may be combined or dispersed as needed. In addition, the functions may be embodied in firmware or hardware equivalents (e.g., integrated circuits, field programmable gate arrays (FPGAs), etc.) in whole or in part.

[0158] References in this disclosure to "one embodiment," "an embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is considered that it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0159] It should be understood that although the terms "first" and "second" etc. can 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 element. For example, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element without departing from the scope of this disclosure. As used herein, the term "and / or" includes any and all combinations of one or more listed associated items.

[0160] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "one", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when used herein, the terms "include", "have", "comprise" specify the presence of the claimed features, elements and / or components, but do not exclude the presence or increase of one or more other features, elements, components and / or their combinations. The terms "connect", "being connected" and / or "connected" used herein cover direct and / or indirect connections between two elements.

[0161] The present disclosure includes any novel feature or combination of features disclosed herein, whether explicit or any generalization thereof. When read in conjunction with the accompanying drawings, various modifications and changes to the above exemplary embodiments of the present disclosure may become apparent to those skilled in the relevant art in view of the above description. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of the present disclosure.

Claims

1. A method performed by a network node (1300) implementing an access and mobility management function (AMF) (1400) entity, comprising: Detect (202) that the state of the terminal device changes from unreachable to reachable; as well as sending (204) a report indicating that the terminal device is reachable to the first entity, wherein the report includes a maximum availability time during which the terminal device is expected to be reachable, The first entity is one of the following: a UDM entity, a network open function NEF entity, an application function AF entity, a short message service SMS entity, a service capability server SCS entity, an application server AS entity, a session management function SMF entity and a user plane function entity; The maximum availability time that the terminal device is expected to reach is used by one of the AF entity, the SMF entity, the SCS entity, the AS entity, the SMF entity, the UPF entity, and the NEF entity to prioritize the transmission of messages or data for multiple terminal devices; The maximum availability time is derived based on an energy saving configuration of the terminal device, and the energy saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and At least one parameter related to periodic registration timer control for MICO mode.

2. The method according to claim 1, wherein: The maximum availability time indicates an absolute point in time.

3. The method according to claim 1 or 2, further comprising: receiving (301) from a second entity a subscription request for event reports related to reachability of the terminal device; as well as The report is sent based on the subscription request.

4. The method according to any one of claims 1 to 3, wherein: The maximum availability time is derived by the following operations: determining (408) a period of time for which the terminal device is to remain reachable after the state of the terminal device is changed from unreachable to reachable; The current time plus the length of the period is determined (410) as the maximum availability time.

5. A method according to claim 3 or claim 4 when dependent on claim 3, wherein: The second entity is one of a unified data management UDM entity, a network open function NEF entity, a network data analysis function NWDAF entity, and a session management function SMF entity.

6. A method performed by a network node (1300) implementing a unified data management (UDM) entity (1500), comprising: receiving (502) a first report from an access and mobility management function, AMF entity, indicating that a terminal device is reachable, wherein the first report contains a maximum availability time during which the terminal device is expected to be reachable; and sending (504) a second report indicating that the terminal device is reachable to a third entity, wherein the second report includes the maximum availability time, wherein the maximum availability time is derived based on a power saving configuration of the terminal device, and wherein the power saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and at least one parameter related to periodic registration timer control for MICO mode; The third entity is one of the following: a network open function NEF entity, an application function AF entity, an SMS entity, a service capability server SCS entity, and an application server AS entity, and the maximum available time is used by the third entity to prioritize the transmission of messages or data for multiple terminal devices.

7. The method according to claim 6, further comprising: In response to a triggering event indicating that the third entity requires event reports related to the reachability of the terminal device, a first subscription request for event reports related to the reachability of the terminal device is sent (601) to the AMF entity.

8. The method according to claim 7, wherein: The triggering event is at least one of the following: receiving a message from a short message service gateway mobile service switching center SMS-GMSC indicating that SMS delivery to the terminal device has failed; and A second subscription request for event reports related to reachability of the terminal device is received from a network opening function (NEF) entity.

9. A method performed by a network node (1300) implementing a network open function NEF entity (1600), comprising: Receiving (702) a first report indicating that a terminal device is reachable from a unified data management (UDM) entity (1500) or an access and mobility management function (AMF) entity (1400), wherein the first report contains a maximum availability time during which the terminal device is expected to be reachable; and sending (704) a second report indicating that the terminal device is reachable to a fourth entity, wherein the second report includes the maximum availability time, wherein the maximum availability time is derived based on a power saving configuration of the terminal device, and wherein the power saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and at least one parameter related to periodic registration timer control for MICO mode; The fourth entity is one of the following: an application function AF entity, a service capability server SCS entity and an application server AS entity, and the maximum available time is used by the fourth entity to prioritize the transmission of messages or data for multiple terminal devices.

10. The method according to claim 9, further comprising: receiving (801) from the fourth entity a first subscription request for event reports related to reachability of the terminal device; as well as A second subscription request for event reports related to reachability of the terminal device is sent (803) to the UDM entity.

11. A method performed by a network node (1300) implementing a service consumer (1700), comprising: receiving (902) one or more reports from a service provider indicating that one or more terminal devices are reachable, wherein each of the one or more reports includes a maximum availability time at which the terminal device is expected to be reachable; and sending (904) one or more messages or data to the one or more terminal devices based on the maximum availability time of the one or more terminal devices, wherein when a plurality of reports indicating that a plurality of terminal devices are reachable are received, the messages or data are sent to the plurality of terminal devices by sorting the plurality of messages or data based on the maximum availability time of the plurality of terminal devices; The maximum availability time is derived based on an energy saving configuration of the terminal device, and the energy saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and at least one parameter related to periodic registration timer control for MICO mode; The service provider is one of the following: a unified data management UDM entity, a network open function NEF entity, an access and mobility management function AMF entity, and a session management function SMF entity; and / or The service user is one of the following: a short message service SMS entity, an application function AF entity, a service capability server SCS entity, an application server AS entity, a network open function NEF entity, an SMF entity, and a user plane function UPF entity.

12. The method according to claim 11, wherein: sorting the messages or data in ascending order of the maximum availability times of the plurality of terminal devices; and Wherein, the message or data is sent to the multiple terminal devices in ascending order of the maximum availability time.

13. The method according to claim 11 or 12, wherein: The one or more messages are short message service SMS messages, or the one or more messages are used for non-internet protocol, ie non-IP, data transfer NIDD.

14. A network node (1300) implementing an access and mobility management function AMF entity (1400), comprising: at least one processor (1310); as well as at least one memory (1320), the at least one memory (1320) containing instructions executable by the at least one processor (1310), whereby the AMF entity (1300) is operable to: Detect that the terminal device status changes from unreachable to reachable; as well as sending a report indicating that the terminal device is reachable to the first entity, wherein the report includes a maximum availability time during which the terminal device is expected to be reachable, The first entity is one of the following: a UDM entity, a network open function NEF entity, an application function AF entity, a short message service SMS entity, a service capability server SCS entity, an application server AS entity, a session management function SMF entity and a user plane function entity; The maximum availability time that the terminal device is expected to reach is used by one of the AF entity, the SMF entity, the SCS entity, the AS entity, the SMF entity, the UPF entity, and the NEF entity to prioritize the transmission of messages or data for multiple terminal devices; The maximum availability time is derived based on an energy saving configuration of the terminal device, and the energy saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and At least one parameter related to periodic registration timer control for MICO mode.

15. The AMF entity (1300) according to claim 14, wherein: The AMF entity (1300) is operable to perform a method according to any one of claims 2 to 5.

16. A network node (1300) implementing a unified data management (UDM) entity (1500), comprising: at least one processor (1310); as well as at least one memory (1320), the at least one memory (1320) containing instructions executable by the at least one processor (1310), whereby the UDM entity (1300) is operable to: Receiving a first report from an access and mobility management function (AMF) entity indicating that a terminal device is reachable, wherein the first report contains a maximum availability time during which the terminal device is expected to be reachable; and sending a second report indicating that the terminal device is reachable to a third entity, wherein the second report includes the maximum availability time, The maximum availability time is derived based on an energy saving configuration of the terminal device, and the energy saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and at least one parameter related to periodic registration timer control for MICO mode; The third entity is one of the following: a network open function NEF entity, an application function AF entity, an SMS entity, a service capability server SCS entity, and an application server AS entity, and the maximum available time is used by the third entity to prioritize the transmission of messages or data for multiple terminal devices.

17. The UDM entity (1300) according to claim 16, wherein: The UDM entity (1300) is operable to perform the method according to claim 7 or 8.

18. A network node (1300) implementing a network open function NEF entity (1600), comprising: at least one processor (1310); as well as at least one memory (1320), the at least one memory (1320) containing instructions executable by the at least one processor (1310), whereby the NEF entity (1300) is operable to: Receiving a first report indicating that a terminal device is reachable from a unified data management (UDM) entity (1500) or an access and mobility management function (AMF) entity (1400), wherein the first report includes a maximum availability time during which the terminal device is expected to be reachable; and sending a second report indicating that the terminal device is reachable to a fourth entity, wherein the second report includes the maximum availability time, The maximum availability time is derived based on an energy saving configuration of the terminal device, and the energy saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and at least one parameter related to periodic registration timer control for MICO mode; The fourth entity is one of the following: an application function AF entity, a service capability server SCS entity and an application server AS entity, and the maximum available time is used by the fourth entity to prioritize the transmission of messages or data for multiple terminal devices.

19. The NEF entity (1300) according to claim 18, wherein: The NEF entity (1300) is operable to perform the method according to claim 10.

20. A network node (1300) implementing a service user (1700), comprising: at least one processor (1310); as well as at least one memory (1320), the at least one memory (1320) containing instructions executable by the at least one processor (1310), whereby the service consumer (1300) is operable to: receiving one or more reports from a service provider indicating that one or more terminal devices are reachable, wherein each of the one or more reports contains a maximum availability time at which the terminal device is expected to be reachable; and sending one or more messages to the one or more terminal devices based on the maximum availability time of the one or more terminal devices, wherein when receiving a plurality of reports indicating that a plurality of terminal devices are reachable, sending the messages or data to the plurality of terminal devices by sorting the plurality of messages or data based on the maximum availability time of the plurality of terminal devices; The maximum availability time is derived based on an energy saving configuration of the terminal device, and the energy saving configuration of the terminal device includes one or more of the following: at least one parameter related to an extended connection time for a mobile initiated only connection MICO mode; at least one parameter related to the active time of the MICO mode; and at least one parameter related to periodic registration timer control for MICO mode; The service provider is one of the following: a unified data management UDM entity, a network open function NEF entity, an access and mobility management function AMF entity, and a session management function SMF entity; and / or The service user is one of the following: a short message service SMS entity, an application function AF entity, a service capability server SCS entity, an application server AS entity, a network open function NEF entity, an SMF entity, and a user plane function UPF entity.

21. The service user (1300) according to claim 20, wherein: The service consumer (1300) is operable to perform the method according to claim 12 or 13.

22. A computer-readable storage medium (1320) storing instructions, which, when executed by at least one processor (1310) when associated with a mobility management function (AMF) entity (1400), causes the AMF entity to perform a method according to any one of claims 1 to 5, or The instructions, when executed by at least one processor (1310) when associated with a unified data management (UDM) entity (1500), cause the UDM entity to perform a method according to any one of claims 6 to 8, or The instructions, when executed by at least one processor (1310) when associated with a network opening function NEF entity (1600), cause the NEF entity to perform the method according to claim 9 or 10, or The instructions, when executed by at least one processor (1310) when associated with a service consumer (1700), cause the service consumer to perform a method according to any one of claims 11 to 13.

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