Network function selection

Abstract

Example embodiments of the present disclosure relate to selecting a target network function for event subscription or opening. In one aspect, a first network device sends a first request message to a second network device for selecting a network function for event subscription. The first request message comprises event information to be subscribed. The first network device receives a first response message from the second network device, the first response message including an identity of a selected network function of the plurality of network functions. In this way, the specific network function can be allocated to the first network device requesting event subscription based on the event to be subscribed, thereby improving the performance of the communication network.

Description

Technical Field

[0001] Various exemplary embodiments of the present disclosure generally relate to the field of communications, and in particular to a terminal device, a network device, and a method and apparatus for selecting a network function (eg, for event subscription or opening). Background Art

[0002] A communication network can be considered as a facility that enables communication between two or more communication devices or provides a communication device with access to a data network. A mobile communication network or wireless communication network is an example of a communication network. Application servers can provide services to communication devices. Such communication networks operate according to standards such as those provided by 3GPP (3rd Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). An example of a standard is the so-called 5G (5th Generation) standard provided by 3GPP.

[0003] From a standardization perspective, 3GPP Release 19 has approved the study of key issues affecting the Internet Protocol Multimedia Subsystem (IMS) architecture, interfaces, and procedures to support IMS capability exposure in the context of IMS data channel sessions. Summary of the Invention

[0004] Generally speaking, example embodiments of the present disclosure provide a solution for selecting a network function (eg, for event subscription or opening).

[0005] In a first aspect, a first network device is provided. The first network device may include at least one processor and at least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the first network device to at least: send a first request message to a second network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to; and receive a first response message from the second network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0006] In a second aspect, a second network device is provided. The second network device may include at least one processor and at least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the second network device to at least: receive a first request message from a first network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to; and send a first response message to the first network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0007] In a third aspect, a third network device is provided. The third network device may include at least one processor and at least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the third network device to at least: receive a request message for capability handling from a first network device, the request message including an identity of a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process; and determine, based on the identity of the selected function, a selected function from the plurality of network functions to process the request message for capability handling.

[0008] In a fourth aspect, a fourth network device is provided. The fourth network device may include at least one processor and at least one memory, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the fourth network device to at least: send capability information of the fourth network device to a second network device for registration with the second network device; and receive a response message from the second network device, the response message including a registration result.

[0009] In a fifth aspect, a fourth network device is provided. The fourth network device may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the fourth network device to at least: receive a request message from a first network device to subscribe to an event at a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process, wherein the request message to subscribe to the event at the selected network function includes an identity of the selected network function; and send a response message to the first network device, the response message including a result of the subscription.

[0010] In a sixth aspect, a method implemented at a first network device is provided. The method may include: sending a first request message to a second network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed; and receiving a first response message from the second network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0011] In a seventh aspect, a method implemented at a second network device is provided. The method may include: receiving a first request message from a first network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed; and sending a first response message to the first network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0012] In an eighth aspect, a method implemented at a third network device is provided. The method may include: receiving a request message for capability handling from a first network device and including an identity of a selected network function, the selected network function selected from a plurality of network functions during a network function selection process; and determining, based on the identity of the selected function, a selected function from the plurality of network functions to process the request message for capability handling.

[0013] In a ninth aspect, a method implemented at a fourth network device is provided, which may include: sending capability information of the fourth network device to a second network device for registration in the second network device; and receiving a response message from the second network device, the response message including a registration result.

[0014] In a tenth aspect, a method implemented at a fourth network device is provided. The method may include: receiving a request message from a first network device to subscribe to an event at a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process, wherein the request message to subscribe to the event at the selected network function includes an identity of the selected network function; and sending a response message to the first network device, the response message including a result of the subscription.

[0015] In an eleventh aspect, an apparatus is provided. The apparatus may include means for sending a first request message to a second network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to; and means for receiving a first response message from the second network device, the first response message including an identity of a selected network function from a plurality of network functions.

[0016] In a twelfth aspect, an apparatus is provided. The apparatus may include means for receiving a first request message for selecting a network function for event subscription from a first network device, wherein the first request message includes event information to be subscribed to; and means for sending a first response message to the first network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0017] In a thirteenth aspect, an apparatus is provided. The apparatus may include means for receiving, from a first network device, a request message for capability handling including an identity of a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process; and means for determining, based on the identity of the selected function, a selected function from the plurality of network functions to process the request message for capability handling.

[0018] In a fourteenth aspect, an apparatus is provided. The apparatus may include a component for sending capability information of a fourth network device for registration in the second network device to a second network device; and a component for receiving a response message from the second network device, the response message including a registration result.

[0019] In a fifteenth aspect, an apparatus is provided. The apparatus may include means for receiving, from a first network device, a request message for subscribing at a selected network function event, the selected network function event being selected from a plurality of network functions during a network function selection process, wherein the request message for subscribing at the selected network function event includes an identity of the selected network function; and means for sending a response message to the first network device, the response message including a result of the subscription.

[0020] In a sixteenth aspect, a non-transitory computer-readable medium is provided, comprising program instructions, which, when implemented by a device, cause the device to at least perform the method according to any one of aspects six to ten of the present application.

[0021] In a seventeenth aspect, a computer program is provided, which includes instructions that, when executed by a device, cause the device to at least perform the method according to any one of aspects six to ten of the present application.

[0022] In an eighteenth aspect, a first network device is provided. The first network device may include a transmitting circuit system configured to transmit a first request message for selecting a network function for event subscription to a second network device, wherein the first request message includes event information to be subscribed to; and a receiving circuit system configured to receive a first response message from the second network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0023] In a nineteenth aspect, a second network device is provided. The second network device may include a receiving circuit system configured to receive a first request message from a first network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to; and a sending circuit system configured to send a first response message to the first network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0024] In a twentieth aspect, a third network device is provided. The third network device may include a receiving circuit system for receiving a request message for capability handling from a first network device and including an identity of a selected network function, the selected network function selected from a plurality of network functions during a network function selection process; and a determining circuit system for determining a selected function from the plurality of network functions to process the request message for capability handling based on the identity of the selected function.

[0025] In a twenty-first aspect, a fourth network device is provided. The fourth network device may include a transmitting circuit system configured to transmit capability information of the fourth network device to a second network device for registration in the second network device; and a receiving circuit system configured to receive a response message from the second network device, the response message including a result of the registration.

[0026] In a twenty-second aspect, a fourth network device is provided. The fourth network device may include receiving circuitry configured to receive, from a first network device, a request message for subscribing to events at a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process, wherein the request message for subscribing to events at the selected network function includes an identity of the selected network function; and transmitting circuitry configured to transmit a response message to the first network device, the response message including a result of the subscription.

[0027] It should be understood that this summary of the invention is not intended to identify the key or essential features of the various embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Some example embodiments will now be described with reference to the accompanying drawings, in which

[0029] Figure 1 illustrates an example of a network environment in which some embodiments of the present disclosure may be implemented;

[0030] Figure 2A illustrates an example signaling process for selecting a network function according to some embodiments of the present disclosure;

[0031] Figure 2B illustrates an example signaling process for selecting a network function for handling capability handling according to some embodiments of the present disclosure;

[0032] Figure 2C illustrates an example signaling process for selecting a network function for handling capability handling according to some embodiments of the present disclosure;

[0033] Figure 3 illustrates an example signaling procedure for DCSF registration and selection according to some embodiments of the present disclosure;

[0034] Figure 4 illustrates an example signaling procedure for DCSF registration and selection according to some embodiments of the present disclosure;

[0035] Figure 5illustrates an example signaling procedure for determining a DCSF for capability handling according to some embodiments of the present disclosure;

[0036] Figure 6 illustrates an example signaling procedure for determining a DCSF for capability handling according to some embodiments of the present disclosure;

[0037] Figure 7 illustrates a flow chart of an example method implemented at a first network device according to some embodiments of the present disclosure;

[0038] Figure 8 illustrates a flow chart of an example method implemented at a second network device according to some embodiments of the present disclosure;

[0039] Figure 9 illustrates a flow chart of an example method implemented at a third network device according to some embodiments of the present disclosure;

[0040] Figure 10 illustrates a flow chart of an example method implemented at a fourth network device according to some embodiments of the present disclosure;

[0041] Figure 11 illustrates a flow chart of an example method implemented at a fourth network device according to some embodiments of the present disclosure;

[0042] Figure 12 illustrates a simplified block diagram of a device suitable for implementing some embodiments of the present disclosure; and

[0043] Figure 13 A block diagram illustrating an example of a computer-readable medium according to some embodiments of the present disclosure is illustrated.

[0044] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0045] Now, the principle of the present disclosure will be described with reference to some embodiments. It should be understood that the description of these embodiments is only for the purpose of illustrating and helping those skilled in the art to understand and implement the present disclosure, and does not impose any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various ways except for the manner described below.

[0046] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0047] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc., indicate that the described embodiment may include a particular characteristic, structure, or feature, but not every embodiment must include the particular characteristic, structure, or feature. Moreover, these phrases do not necessarily refer to the same embodiment. Furthermore, when a particular characteristic, structure, or feature is described in connection with an embodiment, it should be noted that, whether or not explicitly described, such characteristic, structure, or feature may affect the performance of other embodiments within the knowledge of those skilled in the art.

[0048] It should be understood that although the terms "first" and "second" and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the enumerated items.

[0049] As used herein, term is only used to describe the purpose of specific embodiment, is not intended to limit embodiment.As used herein, unless context clearly indicates otherwise, singular form " one ", " one " and " the " also should include plural form.It should also be understood that term " include (includes) ", " including (including) ", " have (has) ", " have (having) ", " including (includes) " and / or " including (including) " when used in this article, specifies the existence of described characteristic, element and / or parts etc., but does not exclude the existence or addition of one or more other characteristics, elements, parts and / or their combination.As used herein, " at least one of the following: < list of two or more elements > " and " at least one of < list of two or more elements > " and similar wording, wherein the list of two or more elements is joined by " and " or ", means at least one element in element or at least two or more elements in element, or at least all elements.

[0050] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0051] (a) pure hardware circuit implementation (such as implementation in analog and / or digital circuitry only) and

[0052] (b) a combination of hardware circuitry and software such as (as applicable):

[0053] (i) a combination of analog and / or digital hardware circuit(s) and software / firmware, and

[0054] (ii) any portion of a hardware processor(s) with software (including digital signal processor(s), software and memory(s) that work together to enable a device such as a mobile phone or server to perform various functions) and

[0055] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), require software (such as firmware) to operate, but when software is not required for operation, the software may not be present.

[0056] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example, and if applicable to a particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0057] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, the communication between the terminal device and the network equipment in the communication network can be performed according to any suitable generation of communication protocols, including but not limited to first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and / or any other protocols currently known or developed in the future. The various embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communications, there will certainly be future types of communication technologies and systems through which the present disclosure can be embodied. The scope of the present disclosure should not be considered to be limited to the above-mentioned systems.

[0058] As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. A network device may refer to a base station (BS) or an access point (AP), depending on the terminology and technology used, for example, a Node B (Node B or NB), an evolved Node B (eNodeB or eNB), a NR NB (also known as a gNB), a remote radio unit (RRU), a radio head (RH), a radio frequency head (RRH), a relay, a low-power node (such as a femto, pico, etc.).

[0059] The term "terminal device" refers to any end device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), user station (SS), portable user station, mobile station (MS) or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablet computers, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, game terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop mounted devices (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (such as remote surgery), industrial devices and applications (such as robots and / or other wireless devices operating in industrial and / or automated process chain environments), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0060] As mentioned above, 3GPP Release 19 has approved the study of “the impact on the Internet Protocol Multimedia Subsystem (IMS) architecture, interfaces and procedures to support IMS capability exposure in the context of IMS data channel sessions”. For example, the issues to be studied may include: (1) enhancing the IMS architecture, interfaces and procedures to expose IMS services in the following IMS data channel related scenarios: IMS data channel activation, update and release, for example, this includes activation, update and release of application and bootstrap data channels; and (2) whether and how an application server can request the use of the bootstrap data channel to download a specific application.

[0061] As defined in standards (such as AC.2 of TS23.228), the Data Channel Signaling Function (DCSF) is a signaling control function that provides data channel (DC) control logic, which means that if a Data Channel Application Server (DC AS) wants to subscribe to a certain DC-related event (such as bootstrap DC establishment, bootstrap DC update, update release, application DC establishment, application DC update, application DC release, or DC application download), it can select a DCSF that can handle the DC-related event (for example, via the network exposure function (NEF)). In other words, the selection of DCSF plays a vital role in DC-related event subscription and / or DC-related event opening to ensure that the selected DCSF can open the subscribed DC-related events, especially when the subscribed DC-related events have not occurred during the subscription period. Furthermore, in order to handle exposure triggered DC capability handling, it is necessary to ensure that the same DCSF provides services for DC-related event exposure and then provides services for DC capability handling, so that IMS session information and other information related to the exposure event (for example, session ID, call ID or called ID) (especially in non-standalone DCs) are available in the DCSF.

[0062] Therefore, at least two issues may need to be addressed. First, an appropriate approach needs to be considered for selecting a DCSF for DC-related event subscription / expansion, even in cases where the event never occurs during the event subscription phase. Second, it needs to be ensured that the selected DCSF that provides services for DC-related event subscription and / or expiration can also provide services for DC capability disposal triggered by event expiration.

[0063] According to various embodiments of the present disclosure, a solution for selecting a target network function for event subscription or exposure is provided. A first network device sends a first request message to a second network device for selecting a network function for event subscription. The first request message includes information about the event to be subscribed to. The first network device receives a first response message from the second network device, the first response message including the identity of a selected network function from a plurality of network functions. In this way, a specific network function can be assigned to the first network device requesting event subscription based on the event to be subscribed to, thereby improving the performance of the communication network.

[0064] Figure 1The diagram illustrates an example of a network environment 100 in which some embodiments of the present disclosure may be implemented. In the description of the example embodiments of the present disclosure, the network environment 100 may also be referred to as a communication system 100 (e.g., a portion of a communication network). For illustrative purposes only, various aspects of the example embodiments will be described in the context of one or more terminal devices and network devices communicating with each other. However, it should be appreciated that the description herein may be applicable to other types of devices or other similar devices referenced using other terms.

[0065] Network device 110 may provide services to terminal device 120, and network device 110 and terminal device 120 may communicate data and control information with each other. In some embodiments, network device 110 and terminal device 120 may communicate over a direct link / channel.

[0066] In the communication system 100, the link from the network device 110 to the terminal device 120 is called the downlink (DL), and the link from the terminal device 120 to the network device 110 is called the uplink (UL). In the downlink, the network device 110 is a transmitting (TX) device (or transmitter), and the terminal device 120 is a receiving (RX) device (or receiver). In the uplink, the terminal device 120 is a transmitting (TX) device (or transmitter), and the network device 110 is an RX device (or receiver).

[0067] The network device 110 may include multiple network functions, such as a data channel application server (DC AS) 111, a network exposure function (NEF) 112, a network repository function (NRF) 113, a data channel signaling function (DCSF) 114, and an Internet Protocol Multimedia Subsystem Application Server (IMSAS) 115. These functions will be described in detail below.

[0068] Communications in network environment 100 may be implemented according to any suitable communication protocol, including, but not limited to, fourth generation (4G) and fifth generation (5G) cellular communication protocols, wireless local area network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol currently known or developed in the future. Furthermore, communications may utilize any suitable wireless communication technology, including, but not limited to, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread spectrum OFDM (DFT-s-OFDM), and / or any other technology currently known or developed in the future.

[0069] It should be understood that Figure 1 The number of devices shown and their connection relationships and types are for illustration purposes only and do not present any limitation. Communication system 100 may include any suitable number of devices adapted to implement various embodiments of the present disclosure.

[0070] As mentioned above, a DCSF must be selected that can handle DC-related events via the NEF. In particular, if a bootstrap DC or application DC has not yet been established, an appropriate DCSF must be selected. For example, a DC AS subscribes to events such as "Bootstrap DC Established" or "DC Application X Downloaded." If a bootstrap DC has not yet been established or application X has not yet been downloaded, a DCSF must still be selected to handle the event subscription or opening. This event subscription or opening will be selected to establish the bootstrap DC or download DC Application X.

[0071] For example, during the DC event opening period, the DC AS may subscribe to DC events at the DCSF. The DCSF may be a cluster with a fully qualified domain name (FQDN). Any DCSF in the cluster can serve the DC AS. However, during the subscription period, a specific DCSF cannot be assigned to the DC AS based on the event to be subscribed. For example, a solution technical document has been discussed that proposes subscribing to the IMS AS for event opening. However, a disadvantage of these proposals is that the IMS AS cannot open some DC-related events, such as downloading an application, while the subscribed DCSF for DC events can include all DC-related event openings. Moreover, when the DC-related event to be subscribed has not occurred during the subscription period, the selection of the DCSF for subscription is crucial. Therefore, the selection of the DCSF needs to be studied. That is, even if the event never occurs during the event subscription phase, it is necessary to consider an appropriate approach for selecting the DCSF for DC-related event subscription and / or opening.

[0072] In the following, reference Figure 2A An example signaling process 200A for selecting a network function for event subscription is described. For discussion purposes, reference may be made to Figure 1 The process 200A is described. The process 200A may include the following: Figure 1The illustrated network device 110 includes multiple network functions, such as DC AS 111, NEF 112, NRF 113, DCSF 114, and IMS AS 115. It should be understood that DC AS 111 may be an example of the first network device 201, NEF 112 may also be an example of the first network device, NRF 113 may be an example of the second network device 202, IMS AS 115 may be an example of the third network device 203, and DCSF 114 may be an example of the fourth network device 204. It should be understood that although Figure 1 The process 200A is described in the communication environment 100 of FIG. 1 , but the process can also be applied to other communication scenarios with similar problems.

[0073] like Figure 2A As shown, in process 200A, the fourth network device 204 sends (211) its capability information 231 for registration in the second network device to the second network device 202. The second network device 202 receives (212) the capability information 231 and sends (213) the registration result via a response message 232 including the result of the registration, and then the fourth network device 202 can receive (214) the response message 232. For example, a DCSF registers with an NRF using its network function profile (NFP) and its DCSF identity. The registered DCSF can also update its NR profile. The network function profile includes functional information. It should be understood that all DCSFs can register in the NRF using their NF profiles and identities respectively.

[0074] In some embodiments, the capability information of the fourth network device 202 includes: the identity of one or more terminal devices that the network function can serve; the identity of one or more applications that the network function can serve; location or area information that the network function can serve; the type of event that the network function can serve; the specific event that the network function can serve; or any combination thereof. After registering the capabilities of each fourth network device (e.g., DCSF) in the second network device (e.g., NRF), the second network device may learn the capabilities of all fourth network devices. It should be understood that the second network device 202 can learn the capabilities of the fourth network device 204 in other ways besides registration, and registration is only an example way to learn the network function profile.

[0075] Then, first network device 201 sends (215) a first request message 233 to second network device 202, the first request message being used to select a network function for event subscription. For example, first request message 233 includes event information to be subscribed. Then, second network device 202 receives (216) first request message 233. Then, second network device 202 sends (217) a first response message 234, the first response message 234 including an identity of a selected network function from a plurality of network functions, and first network device 201 receives (218) first response message 234.

[0076] In some embodiments, the first request message 233 includes a data channel signaling function (DCSF) selection request, and the event subscription includes a data channel (DC) event. In some embodiments, the event information to be subscribed to includes the name of the event, the type of event, the identities of one or more terminal devices, the identities of one or more applications to be subscribed to, the location or region information of the served terminal device, or any combination thereof. In some embodiments, the identity of the selected network function includes a registered network function profile, the address of the selected network function, the unique identifier (ID) of the selected network function, or any combination thereof.

[0077] In some embodiments, the first network device 201 includes a DC application server (DC AS), which is a trusted party. In these embodiments, the first network device 201 also sends (219) a second request message 235 to the selected fourth network device, the second request message being used to subscribe to events at the selected fourth network device. The selected fourth network device 204 then receives (220) the second request message 235 and then sends (221) a second response message 236, the second response message 236 including a result of the subscription or indicating success or failure of the subscription, and then the first network device 201 receives (222) the second response message 236. In these embodiments, the DSAS that sends the first request message for subscribing to events at the selected fourth network device is a trusted party, and it can send the request directly to the selected fourth network device, the request being used to subscribe to events at the selected fourth network device.

[0078] In some embodiments, first network device 201 includes a network open function (NEF), and first network device 201 sends a second request message 235 and receives a second response message 236. In these embodiments, first network device 201 (e.g., NEF) also receives a third request message from a DC AS for subscribing to an event and including event information. In some examples, the NEF sends first request message 233 for selecting a network function based on receipt of the third request message. In these embodiments, the DC AS can be a trusted or untrusted party. In some embodiments, based on receiving the second response message from the selected network function, NEF 202 also sends a third response message to the DC AS in response to the third request message. For example, the third response message indicates the success or failure of the subscription.

[0079] Since the second network device has obtained the capabilities of all fourth network devices or all candidate network functions and can use the selected fourth network device or network function to respond to the first network device, based on the capabilities of the registered network functions and the event information to be subscribed, a selected network function that can provide sufficient capabilities to open the subscribed event can be selected.

[0080] Through this process 200A, based on the event to be subscribed, a specific fourth network device or network function (e.g., DCSF) can be assigned to the first network device (e.g., DC AS) requesting event subscription. Even if the event never occurs during the event subscription phase, an appropriate network function can be selected for event subscription and / or opening.

[0081] As mentioned above, the opening of DC-related events may trigger DC capability handling requests (such as DC application update or upload, application DC establishment). Use cases of DC capability handling triggered by the opening of DC events have been submitted and discussed. For example, DC capability handling can be application DC establishment in person-to-person (P2P), person-to-application (P2A) and person-to-application-to-person (P2A2P) scenarios defined in standards (such as clause AC.7 of TS23.228 or other DC capabilities). For example, for a DC event to download DC application X, the opened information for the DC event may trigger a need for the DC AS to create an application DC to be used to handle communications related to the packets of the downloaded application X. When the IMS network receives a request from the DC AS, it is also necessary to determine the DCSF to provide services for DC capability handling, which has been selected to provide services for the opening of DC-related events. For example, during DC capability handling (such as bootstrap DC establishment or application DC establishment), the IMS AS determines the DCSF based on local configuration as defined in standards (such as AC.7.2.1 of TS23.228), and the determined DCSF can determine policies related to how to handle the application DC establishment request. Therefore, according to current protocols, the selection of the DCSF for DC capability handling is based on the local configuration of the DCSF, such as load balancing, and cannot take into account the triggering of open DC-related events, and this is not currently supported by the DC AS.

[0082] In order to process the DC capability handling triggered by an open, it is necessary to ensure that the same DCSF that provides services for the DC-related event opening and later provides services for the DC capability handling, so that the IMS session information and other information related to the open event are available in the DCSF. However, according to current protocols, the selection of the DCSF for DC capability handling is based on the DCSF's local configuration and cannot take into account the triggering of the opened DC-related event, and this is not currently supported by the DC AS. Therefore, it is necessary to ensure that the selected DCSF that provides services for DC-related event subscription and / or opening can also provide services for the DC capability handling triggered by the event open.

[0083] In the following, reference Figure 2B Example signaling process 200B for selecting a network function for handling capability handling. For discussion purposes, reference may be made to Figure 1 The process 200B is described. Figure 1As shown, process 200B may include multiple network functions of network device 110, such as DC AS 111, NEF 112, DCSF 114, and IMS AS 115. It should be understood that DC AS 111 may be an example of the first network device 201, NEF 112 may also be an example of the first network device, IMS AS 115 may be an example of the third network device 203, and DCSF 114 may be an example of the fourth network device 204. It should be understood that although Figure 1 The process 200B is described in the communication environment 100 of FIG. 1 , but the process can also be applied to other communication scenarios with similar problems.

[0084] like Figure 2B As shown, in process 200B, the first network device 201 sends (223) a request message 237 for capability handling, the request message 237 for capability handling including the identity of a selected network function, which is selected from a plurality of network functions in a network function selection process; and then the third network device 203 (e.g., an IMS AS) receives (224) the request message 237. It should be understood that the selected network function is a specific fourth network function, and the request message 237 can be forwarded by any fourth network device 204 that receives the request message 237 from the first network device 201 and does not have to be the selected network function.

[0085] After receiving the request message 237 including the identity of the selected network function, the third network device 203 determines (225) a selected function from the plurality of network functions to process the request message for capability handling. It should be understood that the function determined to process the capability handling is exactly the selected network function selected from the plurality of network functions during the network function selection process.

[0086] In some embodiments, when a subscribed event occurs, first network device 201 receives event subscription information from a selected network function (e.g., a specific fourth network device). Receiving the event subscription information triggers a request message 237 for capability handling, including the identity of the selected network function. This request message 237 is then sent to one or more of the plurality of network functions (e.g., one or more of all registered fourth network devices). In these embodiments, first network device 201 is a DC AS, which is a trusted party. The identity of the selected network function may have been obtained by the DC AS during the network function selection process.

[0087] In some embodiments, first network device 201 includes a network exposure function (NEF). The NEF sends a request message 237 to third network device 203. Before sending request message 237, first network device 201 also receives the identity of the selected network function from the selected network function; sends the identity of the selected network function to the DC AS along with event subscription information; and receives a request message 237 for capability handling from the DC AS, including the identity of the selected network function. In these embodiments, upon receiving the event subscription information and then sending it to the NEF by the DC AS, the DC AS triggers the sending of the request message 237 for capability handling, including the identity of the selected network function. In these embodiments, the DC AS can be either a trusted or untrusted party.

[0088] Thus, through process 200B, the same fourth network device or network function provides services for event exposure and later provides services for capability handling, making IMS session information and other information related to the exposure event available to the fourth network device. In other words, the selected fourth network device or network function that provides services for event subscription and / or exposure can also provide services for capability handling triggered by the event exposure.

[0089] In the following, reference Figure 2C Example signaling process 200C for selecting a network function for handling capability handling. For discussion purposes, reference may be made to Figure 1 The process 200C is described. The process 200C may include the following: Figure 1 The network device 110 is shown as a plurality of network functions, for example, DC AS 111, NEF 112, and DCSF 114. It should be understood that DC AS 111 may be an example of the first network device 201, NEF 112 may also be an example of the first network device, and DCSF 114 may be an example of the fourth network device 204. It should be appreciated that although the Figure 1 The process 200C is described in the communication environment 100 of FIG. 1 , but the process can also be applied to other communication scenarios with similar problems.

[0090] like Figure 2CAs shown, in process 200C, the first network device 201 sends (226) a request message 237 for capability handling to the selected fourth network device 204. The request message 237 includes the identity of the selected fourth network device selected from a plurality of network functions during the network function selection process. The selected fourth network device 204 (e.g., the selected DCSF) then receives (227) the request message 237. It should be understood that the selected fourth network device 204 is a specific fourth network function selected during the network function selection process. After receiving the request message, the selected fourth network device 204 can process the capability handling.

[0091] In these embodiments, if the DC AS is a trusted party, the DC AS can directly determine the target fourth network device 204 based on the identity of the selected network function. The target fourth network device 204 can receive the request message 237 and process the capability disposition. The DC AS can then directly send the request message 237 to the selected fourth network device 204. Otherwise, if the DC AS is an untrusted party, the DC AS can send the request message 237 to the NEF. The NEF can then determine the target fourth network device based on the identity of the selected network function. The target fourth network device can receive the request message 237 and process the capability disposition. The NEF can then send the request message 237 to the selected fourth network device 204.

[0092] Thus, through process 200C, the same fourth network device or network function provides services for event exposure and later provides services for capability handling, making IMS session information and other information related to the exposure event available to the fourth network device. In other words, the selected fourth network device or network function that provides services for event subscription and / or exposure can also provide services for capability handling triggered by the event exposure.

[0093] In the following, reference Figure 3 An example signaling process 300 for DCSF registration and selection according to some embodiments of the present disclosure is described. It should be understood that DC AS 311 may be an embodiment of first network device 201, NEF 312 may also be an embodiment of the first network device, NRF 313 may be an embodiment of second network device 202, IMS AS 315 may be an embodiment of third network device 203, and DCSF 314 may be an example of fourth network device 204.

[0094] In this embodiment, each DCSF 314 registers itself with the NRF 313 using specific information. The DC AS 311 subscribes to DC event notifications or subscriptions via the NEF 312 over the DC3 interface. The NEF 312 sends a request message to the NRF 313 to select an appropriate DCSF 314, and receives the identity of the selected DCSF from the NRF 313 in response. The NEF 312 also forwards the DC-related event subscription request received from the DC AS 311 to the selected DCSF 314, which can later handle the DC event opening for the DC AS 311. In this embodiment, the DC AS 311 can be a trusted party or an untrusted party (such as not within the same public land mobile network (PLMN)).

[0095] like Figure 3 As shown, at step 1, the DCSF 314 registers with the NRF 313 using its network function profile (NFP) and its DCSF identity as defined in the standard (e.g., clause 5.2.2.2.2 of TS 29.510). The registered DCSF may also update its NR profile as defined in the standard (e.g., clause 5.2.2.3 of TS 29.510).

[0096] In some embodiments, the network function profile may include capability information. The NF profile contains all parameters defined in the standard (such as Section 6.1.6.2.2 of TS29.510), and the following capability information as additional parameters: (1) which user ID(s) or UE ID(s) group(s) the DCSF can serve; (2) the ID(s) of the application(s) that the DCSF can serve; (3) the types of events supported by the DCSF; (4) the specific events that the DCSF can serve; and (5) other information, such as location or area information that the DCSF can serve.

[0097] In some embodiments, the DCSF 314 also registers itself with the NRF 313 using its identity. In some embodiments, a new information element (IE) called DCSF identity is proposed, which is used to identify a specific DCSF. The DCSF identity can be a unique identifier (ID), address, or registered NF profile of the DCSF.

[0098] At step 2, NRF 313 responds to DCSF 314 with a success result or a failure result. If the response is successful, DCSF 314 has successfully registered with NRF 313 for potential DC event subscription and / or opening. Similarly, all other DCSFs 314 are registered with NRF 313 in the same way.

[0099] At step 3, DC AS 311 sends a DC event subscription request to NEF 312 via the DC3 interface to request DC event subscription; and in the request, event information to be subscribed may be included. In some embodiments, in order to select DCSF 314 for DC event subscription, DC AS 311 may provide the following event information to be subscribed: (1) the type of event; (2) user ID(s) (groups); (3) application ID(s) to be subscribed; and (4) other information, such as the location or area information of the terminal device to be served. That is, NEF 312 receives a request to subscribe to a specific event from DC AS 311. The request may contain event information, such as the type of event, user ID(s) (groups), application ID(s), and other information (such as the location of the UE to be served).

[0100] At step 4, upon receiving the DC event subscription request, NEF 312 sends a DCSF selection request to NRF 313 to select DCSF 314 from NRF 313. The DCSF selection request may include the event information to be subscribed to received from DC AS 311. At step 5, NRF 313 responds to NEF 312 with a selected DCSF that can provide sufficient capabilities to open the subscribed DC events based on the capabilities of the registered DCSF and the received event information. The selected DCSF 314 to be subscribed to may be identified by a DCSF identity, which may be a registered NF profile, address, or the unique ID of the selected DCSF.

[0101] That is, the NEF 312 is checking with the NRF 313, and the NRF 313 is replying with an appropriate DCSF, and the NEF 312 is selecting an appropriate DCSF whose capability information matches the event information. The selected DCSF 311 may be identified by a unique DCSF identity.

[0102] At step 6, NEF 312 may subscribe to events at DCSF 314, which was selected or provided in the previous step 5. For example, NEF 312 may send a request message to DCSF 314 for subscribing to DCSF 314. In some embodiments, the request message for subscribing to DCSF 314 may include the identity of the selected DCSF 314.

[0103] At step 7, the subscribed DCSF 314 responds to the NEF 312 with a success or failure response message, depending on whether the subscription succeeded or failed. Then, at step 8, the NEF 312 responds to the DC AS 311 with a success or failure response message, depending on the response to step 7. In some embodiments, the NEF 312 may also provide the DCSF identity to the DC AS 311 in the response to step 8 or an additional step.

[0104] In this way, during the event subscription phase when the subscribed DC-related event has not occurred yet, an appropriate DCSF that can provide sufficient capabilities to open the subscribed DC event can be selected through communication between the NRF, NEF and DC AS.

[0105] In the following, reference Figure 4 , an example signaling process 400 for DCSF registration and selection according to some embodiments of the present disclosure is described. In this embodiment, each DCSF 314 registers itself with or in the NRF 313. The DC AS 311 rather than Figure 3 The illustrated NEF 312 requests DCSF selection via the NRF 313 to obtain a DCSF identity that the DC AS 311 can subscribe to DC related events. Figure 3 The illustrated NEF 312 sends a DC-related event subscription request to the DCSF 314 to subscribe to the selected DCSF 314, which may be identified by the obtained DCSF identity. In this embodiment, the DC AS 311 may be a trusted party, for example, in the same PLMN.

[0106] like Figure 4 As shown, steps 1 and 2 may be Figure 3 The steps shown are identical, and the details of these two steps will not be repeated. In step 3, DC AS 311 sends a DC event subscription request to NRF 313. This request may include information about the events to be subscribed to. In other words, DC AS 311 sends the request directly to NRF 313, rather than through NEF 312, and this request may include information about the events to be subscribed to.

[0107] At step 4, NRF 313 responds to DC AS 311 with a selected DCSF 314, and the selected DCSF is able to provide sufficient capabilities to open the subscribed DC events based on the capabilities of the registered DCSF and the event information to be subscribed. The selected DCSF 314 to be subscribed can be identified by a DCSF identity, which can be a registered NF profile, address, or a unique ID of the selected DCSF.

[0108] At step 5, the DC AS 311 may send a DC event subscription request to the selected DCSF 314 provided in the previous step 4 via the DC4 interface to subscribe to the DCSF 314. The DC event subscription request may include the identity of the selected DCSF 314. At step 6, the subscribed DCSF 314 responds to the DC AS with a success or failure result depending on whether the subscription succeeds or fails.

[0109] In this way, through process 400 , during the event subscription phase when the subscribed DC-related event has not occurred, an appropriate DCSF that can provide sufficient capabilities to open the subscribed DC event can be selected through direct communication between the NRF and the DC AS.

[0110] In the following, reference Figure 5 An example signaling process 500 for determining a DCSF for capability handling is described. In the signaling process, the capability handling may be a DC capability handling triggered by a DC event open.

[0111] As discussed above, in order to process the DC capability handling triggered by the opening, the same DCSD needs to be used to open the DC-related event and later provide services for the DC capability handling. Through the signaling process 500, the selected DCSF for providing services for the DC-related event opening can also be determined to provide services for the DC capability handling.

[0112] like Figure 5 As shown, at step 1, Figure 3 and Figure 4 You can register with DCSF as shown in step 1 or 2 of Figure 3 and Figure 4 As shown, the DCSF can be selected for DC-related event subscription and opening. At step 2, one or more subscribed DC-related events occur. The occurrence of the subscribed DC-related events may also include UE 320 and network functions (DC AS 311, NEF 312, NRF 313, DCSF 314 and IMS AS 315), as well as some other network functions (such as Call Session Control Function (CSCF)). CSCF is a network function of the IMS and is configured to control and manage the establishment, modification and release of sessions, and may include a Proxy CSCF (P-CSCF), a Serving CSCF (S-CSCF) and an Interrogating CSCF (I-CSCF).

[0113] At step 3, the subscribed DC-related event(s) are opened from the selected DCSF 314 to the DC AS 311 via a DC event open message. Figure 3 As described above, if the event subscription and / or opening reaches the DC AS via the NEF via DC3, then step 3a may apply. The DCSF identity selected during the DC event subscription needs to be communicated to the DCAS 311 in the DC event open message. However, as described in reference Figure 4 As described, if the event subscription and / or opening reaches the DC AS directly via DC 4, step 3b may be applied. At step 3b, since the DCSF identity has been communicated to DC AS 311 during the DCSF selection process in step 1, the DCSF identity does not need to be included in the DC Event Open message, which means that the DCSF identity is optional in the message.

[0114] At step 4, DC AS 311 is triggered by the open event received in the previous step 3 to request DC capability handling (e.g., apply DC setup) in the IMS network. For example, the DC capability handling request may be triggered by DC AS 311. If the triggered request reaches IMS AS 115 via the DC3 interface through NEF 312 and the DCSF (which may not be the selected DCSF), step 4a may be applied. If the triggered request reaches IMS AS 115 via the DC4 interface through the DCSF (which may not be the selected DCSF), step 4b may be applied. It should be noted that the DCSF to which the triggered request is sent does not have to be the same DCSF determined based on the DCSF identity in step 5.

[0115] At step 5, if the IMS AS 115 determines that the DCSF 314 needs to be notified of the DC capability handling request, the IMS AS 115 selects the DCSF 314 based on the DCSF identity received in the previous step 4. If the IMS AS 115 determines that the DCSF 314 does not need to be notified or the request is not allowed, the IMS AS 115 continues with the normal IMS process to set up the multimedia telephony (MMTel) session.

[0116] At step 6, DC capability handling is handled by the selected DCSF 314. This process depends on the DC capability handling request, for example, P2P application DC establishment as defined in standards such as AC.7.2.1 TS 23.228.

[0117] In the signaling process 500, a DCSF 314 may be selected to provide services for event opening. Furthermore, the DCSF identity of the selected DCSF 314 may be determined. The DCSF identity is shared with the DC AS 311 together with the DC-related event opening information. Once a DC capability handling (e.g., application DC establishment) is triggered by an open DC-related event, the DC AS 311 transmits the received DCSF identity of the selected DCSF 314 to the IMS AS 115, so that the IMS AS 115 can determine the DCSF 314 based on the received DCSF identity to handle the DC capability (e.g., to establish application DC). That is, the DCSF identity that has been selected during the previous DCSF selection process is transmitted from the DC AS or NEF to the IMS AS in the DC capability handling request. The IMS AS can determine the DCSF for processing the DC capability handling request based on the received DCSF identity.

[0118] It should be noted that the relevant UE information (eg, user ID) may be part of the DC event information exposed to the DC AS 311 so that the IMS AS 115 may obtain the correct user ID during the triggered DC capability handling.

[0119] In the following, reference Figure 6 An example signaling process 600 for determining a DCSF for capability handling is described. In this signaling process, the capability handling may also be a DC capability handling triggered by a DC event opening.

[0120] In the signaling process 600, steps 1, 2, and 3 may be associated with Figure 5 The steps described in , and the details of these steps will be omitted. Figure 6 Step 5 and Figure 5 Same as step 6.

[0121] exist Figure 5 In step 4a or 4b, the DC handling request triggered by the event opening is sent from DC AS 311 to IMSAS 115. However, in Figure 6 In step 4a or 4b, the DC handling request triggered by the event opening is sent from the DC AS 311 to the determined DCSF 314. That is, the DC AS 311 can determine the DCSF 314 by itself based on the DCSF identity received in step 3a or 3b, without interacting with the IMS AS 115 for DCSF determination. In this case, the DC AS can directly request the determined DCSF for DC capability handling in step 4a or 4b, and skip the DCSF identification. Figure 5Step 5. Since DC AS 311 and NEF 312 have already received the identity of the DCSF providing services for DC-related event opening, DC AS 311 (which is a trusted party) or NEF 112 (if the DC AS is an untrusted party) can determine the same DCSF providing services for DC capability handling based on the received DCSF identity in step 3a or 3b, and then send a DC capability handling request to the determined DCSF 314 in step 4a or 4b. For example, if the triggered request reaches the determined DCSF 314 via the DC3 interface through NEF 312, step 4a can be applied. If the triggered request reaches the determined DCSF 314 via the DC4 interface, step 4b can be applied.

[0122] In this way, the DCSF identity selected during the previous DCSF selection process is communicated to the DC AS. The DC AS can determine the DCSF for handling the DC capability handling based on the received DCSF identity.

[0123] Figure 7 FIGURE 7 illustrates a flow diagram of an example method 700 implemented at a first network device according to some other embodiments of the present disclosure. For discussion purposes, reference is made to Figures 2A to 2C The method 700 is described from the perspective of the first network device 201 (eg, NEF or DC AS).

[0124] At block 710, the first network device 201 sends a first request message to the second network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to. At block 720, the first network device 201 receives a first response message from the second network device, wherein the first response message includes an identity of the selected network function from the plurality of network functions.

[0125] In some embodiments, the first request message includes a Data Channel Signaling Function (DCSF) selection request, and the event subscription includes a Data Channel (DC) event. In some embodiments, the first network device 201 further sends a second request message to the selected network function to subscribe to the event at the selected network function; and receives a second response message from the selected network function indicating the success or failure of the subscription. In these embodiments, the first network device includes a DC Application Server (DC AS) as a trusted party.

[0126] In some embodiments, first network device 201 includes a network exposure function (NEF), and first network device 202 further receives a third request message from a DC application server (DC AS) for subscribing to an event and including event information, wherein the first request message is sent based on the receipt of the third request message, and wherein the DC AS is a trusted party or an untrusted party. In these embodiments, first network device 201 further sends a third response message to the DC AS for the third request message based on the receipt of the second response message from the selected network function, wherein the third response message indicates the success or failure of the subscription. In these embodiments, the DC application server (DC AS) is a trusted party or an untrusted party.

[0127] In some embodiments, the event information includes at least one of the following: a name of the event; a type of event; the identity of one or more terminal devices; the identity of one or more applications to be subscribed to; or location or region information of the served terminal device. In some embodiments, the identity of the selected network function includes at least one of the following: a registered network function profile; an address of the selected network function (e.g., an IP address or a fully qualified domain name (FQDN)); or a unique identifier (ID) of the selected network function.

[0128] In some embodiments, when a subscribed event occurs, the first network device 201 further receives event subscription information from a selected network function; and upon receiving the event subscription information, sends a fourth request message to one or more network functions among the plurality of network functions, the fourth request message including the identity of the selected network function and for capability handling. In these embodiments, the first network device 201 includes a DC application server (DC AS) as a trusted party.

[0129] In some embodiments, first network device 201 includes a network exposure function (NEF), and first network device 202 further receives an identity of the selected network function from the selected network function; sends the identity of the selected network function to a DC application server (DC AS) while sending event subscription information; and receives a fourth request message for capability handling including the identity of the selected network function from the DC AS, wherein the sending of the fourth request message for capability handling including the identity of the selected network function is based on receiving the fourth request message for capability handling including the identity of the selected network function from the DC AS. In these embodiments, the DC application server (DC AS) is a trusted party or an untrusted party.

[0130] In some embodiments, when the DC AS receives event subscription information, the fourth request message for capability handling is triggered by the DC AS. In some embodiments, the selected network function is determined by the DC AS based on the identity of the selected network function to process the fourth request message for capability handling. In some embodiments, if the DC AS is an untrusted party, the selected network function is determined by the NEF based on the identity of the selected network function to process the fourth request message for capability handling.

[0131] In some embodiments, a fourth request message for capability handling and including an identity of a selected network function is sent to an IP Multimedia Subsystem (IMS) network device via one or more of the plurality of network functions. In these embodiments, the IMS network device determines a selected network function to process the fourth request message for capability handling based on the identity of the selected network function.

[0132] Figure 8 FIGURE 8 is a flow diagram illustrating an example method 800 implemented at the second network device 202 according to some other embodiments of the present disclosure. For discussion purposes, reference is made to Figures 2A to 2C The method 600 is described from the perspective of the second network device 202 (eg, NRF).

[0133] At block 810, second network device 202 receives a first request message from the first network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to. At block 820, second network device 202 sends a first response message to the first network device, wherein the first response message includes an identity of the selected network function from the plurality of network functions.

[0134] In some embodiments, the second network device 202 also receives capability information of each of the multiple network functions from the multiple network functions, registers each of the multiple network functions using the capability information, and sends a second response message to the multiple network functions, where the second response message includes the registration result.

[0135] In some embodiments, the selected network function is selected based on capability information and event information. In some embodiments, the selection request comprises a data channel signaling function (DCSF) selection request, and the event subscription comprises a data channel (DC) event subscription. In some embodiments, the capability information of the network function comprises at least one of the following: the identity of one or more terminal devices that the network function can serve; the identity of one or more applications that the network function can serve; location or area information that the network function can serve; the type of event that the network function can serve; or the specific event that the network function can serve. In some embodiments, the second network device comprises a network repository function (NRF).

[0136] Figure 9 FIGURE 9 is a flow chart illustrating an example method 900 implemented at a third network device according to some other embodiments of the present disclosure. For discussion purposes, reference is made to FIGURE 900. Figures 2A to 2C The method 900 is described from the perspective of the third network device 203 (eg, an IMS AS).

[0137] At block 910, third network device 203 receives a request message for capability handling from a first network device, the request message including the identity of a selected network function selected from a plurality of network functions during a network function selection process. At block 920, third network device 203 determines a selected function from the plurality of network functions based on the identity of the selected function to process the request message for capability handling. In some embodiments, third network device 203 comprises an Internet Protocol Multimedia Subsystem Application Server (IMS AS).

[0138] Figure 10 FIGURE 1 illustrates a flow chart of an example method 1000 implemented at a fourth network device according to some other embodiments of the present disclosure. For discussion purposes, reference is made to Figures 2A to 2C The method 1000 is described from the perspective of the fourth network device 204 (eg, DCSF).

[0139] At block 1010, fourth network device 204 sends capability information of the fourth network device to the second network device for registration with the second network device. At block 1020, fourth network device 204 receives a response message from the second network device, the response message including a result of the registration. In some embodiments, fourth network device 204 includes a data channel signaling function (DCSF).

[0140] Figure 11 FIGURE 1 illustrates a flow chart of an example method 1100 implemented at a fourth network device according to some other embodiments of the present disclosure. For discussion purposes, reference is made to FIGURE 1100. Figures 2A to 2CThe method 1100 is described from the perspective of the fourth network device 204 (eg, DCSF).

[0141] At block 1110, fourth network device 204 receives a request message from the first network device to subscribe to events at a selected network function, the selected network function selected from a plurality of network functions during a network function selection process, wherein the request message to subscribe to events at the selected network function includes an identity of the selected network function. At block 1120, fourth network device 204 sends a response message to the first network device, the response message including a result of the subscription.

[0142] In some embodiments, the fourth network device 204 includes a selected network function serving as a data channel signaling function (DCSF). In some embodiments, when a subscribed event occurs, the fourth network device 204 further sends event subscription information to the first network device, receives a request message for capability handling and an identity of the selected network function from the first network device, and processes the capability handling.

[0143] In some embodiments, an apparatus capable of executing method 700 (e.g., first network device 201) may include components for executing corresponding steps of method 700. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0144] In some embodiments, the apparatus includes a component for sending a first request message to a second network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to; and a component for receiving a first response message from the second network device, wherein the first response message includes an identity of a selected network function among a plurality of network functions.

[0145] In some embodiments, the first request message comprises a Data Channel Signaling Function (DCSF) selection request, and the event subscription comprises a Data Channel (DC) event. In some embodiments, the apparatus further comprises means for sending a second request message to the selected network function for subscribing to events at the selected network function; and means for receiving a second response message from the selected network function indicating success or failure of the subscription. In these embodiments, the apparatus comprises a DC Application Server (DC AS) as a trusted party.

[0146] In some embodiments, the apparatus includes a network exposure function (NEF), and the apparatus further includes a component for receiving a third request message for subscribing to an event and including event information from a DC application server (DC AS), wherein the sending of the first request message is based on the receipt of the third request message, wherein the DC AS is a trusted party or an untrusted party. In these embodiments, the apparatus further includes a component for sending a third response message to the DC AS for the third request message based on the receipt of a second response message from the selected network function, wherein the third response message indicates success or failure of the subscription. In these embodiments, the DC application server (DC AS) is a trusted party or an untrusted party.

[0147] In some embodiments, the event information includes at least one of the following: the name of the event; the type of event; the identification of one or more terminal devices; the identity of one or more applications to be subscribed to; or the location or region information of the served terminal device. In some embodiments, the identity of the selected network function includes at least one of the following: a registered network function profile; the address of the selected network function; or a unique identifier (ID) of the selected network function.

[0148] In some embodiments, the apparatus further comprises means for receiving event subscription information from a selected network function when a subscribed event occurs; and means for sending a fourth request message for capability handling including an identity of the selected network function to one or more of the plurality of network functions upon receiving the event subscription information. In these embodiments, the apparatus comprises a DC application server (DC AS) as a trusted party.

[0149] In some embodiments, the apparatus includes a network exposure function (NEF), and the apparatus further includes means for receiving an identity of the selected network function from the selected network function; means for sending the identity of the selected network function to a DC application server (DC AS) while simultaneously sending event subscription information; and means for receiving a fourth request message for capability handling including the identity of the selected network function from the DC AS, wherein sending the fourth request message for capability handling and including the identity of the selected network function is based on receiving the fourth request message for capability handling and including the identity of the selected network function from the DC AS. In these embodiments, the DC application server (DC AS) is a trusted party or an untrusted party.

[0150] In some embodiments, when the DC AS receives the event subscription information, the DC AS triggers a fourth request message for capability handling. In some embodiments, the DC AS determines the selected network function to process the fourth request message for capability handling based on the identity of the selected network function. In some embodiments, if the DC AS is an untrusted party, the NEF determines the selected network function to process the fourth request message for capability handling based on the identity of the selected network function.

[0151] In some embodiments, a fourth request message for capability handling and including an identity of a selected network function is sent to an IP Multimedia Subsystem (IMS) network device via one or more of the plurality of network functions. In these embodiments, the IMS network device determines a selected network function to process the fourth request message for capability handling based on the identity of the selected network function.

[0152] In some embodiments, the apparatus further comprises means for performing other steps of some embodiments of method 700. In some embodiments, the means comprises at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to implement the performance of the apparatus together with the at least one processor.

[0153] In some embodiments, an apparatus capable of executing method 800 (e.g., second network device 202) may include components for executing corresponding steps of method 800. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0154] In some embodiments, the apparatus includes a component for receiving a first request message from a first network device for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed to; and a component for sending a first response message to the first network device, wherein the first response message includes an identity of a selected network function from a plurality of network functions.

[0155] In some embodiments, the apparatus further comprises a component for receiving capability information of each of the plurality of network functions from the plurality of network functions; a component for registering each of the plurality of network functions using the capability information; and a component for sending a second response message to the plurality of network functions, the second response message including a result of the registration.

[0156] In some embodiments, the selected network function is selected based on capability information and event information. In some embodiments, the selection request comprises a data channel signaling function (DCSF) selection request, and the event subscription comprises a data channel (DC) event subscription. In some embodiments, the capability information of the network function comprises at least one of the following: the identity of one or more terminal devices that the network function can serve; the identity of one or more applications that the network function can serve; location or area information that the network function can serve; the type of event that the network function can serve; or the specific event that the network function can serve. In some embodiments, the apparatus comprises a network repository function (NRF).

[0157] In some embodiments, the apparatus further comprises means for performing other steps of some embodiments of method 800. In some embodiments, the means comprises at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to implement the performance of the apparatus together with the at least one processor.

[0158] In some embodiments, an apparatus capable of executing method 900 (e.g., third network device 203) may include components for executing corresponding steps of method 900. The apparatus may be implemented in any suitable form. For example, the apparatus may be implemented in a circuit system or a software module.

[0159] In some embodiments, the apparatus includes means for receiving a request message for capability handling from a first network device, the request message for capability handling including an identity of a selected network function selected from a plurality of network functions during a network function selection process; and means for determining, based on the identity of the selected function, a selected function from the plurality of network functions to handle the request message for capability handling. In some embodiments, the apparatus includes an Internet Protocol Multimedia Subsystem Application Server (IMS AS).

[0160] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of method 900. In some embodiments, the means comprises at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to implement the performance of the apparatus together with the at least one processor.

[0161] In some embodiments, an apparatus capable of executing method 1000 (e.g., fourth network device 204) may include components for executing corresponding steps of method 1000. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0162] In some embodiments, the apparatus includes means for sending capability information for registering the apparatus in the second network device to the second network device; and means for receiving a response message from the second network device, the response message including a result of the registration. In some embodiments, the apparatus includes a data channel signaling function (DCSF).

[0163] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of method 1000. In some embodiments, the means comprises at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to implement the performance of the apparatus together with the at least one processor.

[0164] In some embodiments, an apparatus capable of executing method 1100 (e.g., fourth network device 204) may include components for executing corresponding steps of method 1100. The components may be implemented in any suitable form. For example, the apparatus may be implemented in a circuit system or a software module.

[0165] In some embodiments, the apparatus includes means for receiving, from a first network device, a request message for subscribing to an event at a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process; and means for sending a response message to the first network device, the response message including a result of the subscription.

[0166] In some embodiments, the apparatus includes a selected network function serving as a data channel signaling function (DCSF). In some embodiments, the apparatus further includes means for sending event subscription information to the first network device when a subscribed event occurs; means for receiving a request message for capability disposition and including an identity of the selected network function from the first network device; and means for processing the capability disposition.

[0167] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of method 1100. In some embodiments, the means comprises at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to implement the performance of the apparatus together with the at least one processor.

[0168] Figure 12 1 is a simplified block diagram of a device 1200 suitable for implementing various embodiments of the present disclosure. The device 1200 may be provided to implement a communication device, such as Figure 1The terminal device 120 and the network device 110 are shown. As shown, the device 1200 includes one or more processors 1210, one or more memories 1220 coupled to the processor 1210, and one or more communication modules 1240 coupled to the processor 1210.

[0169] The communication module 1240 is configured for bidirectional communication. The communication module 1240 has at least one antenna to facilitate communication. The communication interface may represent any interface required to communicate with other network devices.

[0170] Processor 1210 may be of any type suitable for the local technology network and may include, as non-limiting examples, one or more of 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. Device 1200 may have multiple processors, such as application-specific integrated circuit chips, which are time-slave to a clock that synchronizes a main processor.

[0171] Memory 1220 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1224, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1222 and other volatile memories that may not survive the duration of a power outage.

[0172] Computer program 1230 includes computer executable instructions implemented by the associated processor 1210. Program 1230 may be stored in ROM 1224. Processor 1210 may perform any suitable actions and processes by loading program 1230 into RAM 1222.

[0173] The embodiments of the present disclosure can be implemented with the help of a program so that the device 1200 can execute the reference Figure 2A and Figure 6 Any process of the present disclosure discussed. The embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0174] In some embodiments, the program 1230 may be tangibly embodied in a computer-readable medium that may be included in the device 1200 (such as in the memory 1220) or in other storage devices accessible to the device 1200. The device 1200 may load the program 1230 from the computer-readable medium into the RAM 1222 for implementation. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc.

[0175] Figure 13 An example of a computer-readable medium 1300 in the form of a CD or DVD according to some embodiments of the present disclosure is shown. The computer-readable medium has stored thereon a program 1230. It should be noted that although the computer-readable medium 1300 is depicted in the form of a CD or DVD, the computer-readable medium 1300 may be in any other form suitable for carrying or storing the program 1230.

[0176] In general, the various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be implemented by a controller, microprocessor, or other computing device. Although various aspects of the various embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or illustrated and described using some other graphical representations, it should 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 a controller or other computing device, or some combination thereof.

[0177] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions implemented in a device on a target real or virtual processor, such as computer-executable instructions included in a program module, to perform the above-referenced Figures 7 to 11 Methods 700 to 1100 are described. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or split between program modules as needed. The machine-executable instructions of program modules can be implemented in local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0178] The program code for carrying out the disclosed method can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code, when implemented by the processor or controller, enables the function / operation specified in the flow chart and / or block diagram to be realized. The program code can be implemented entirely on a machine, partially on a machine, as an independent software package, partially on a computer, partially on a remote machine, or entirely on a remote machine or server.

[0179] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0180] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the above. More specific examples of computer-readable storage media may include an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. As used herein, the term "non-transient" is a restriction on the medium itself (i.e., a tangible medium, not a signal medium), rather than a restriction on the persistence of data storage (such as RAM and ROM).

[0181] Further, although the operations are depicted in a particular order, this should not be understood as requiring that the operations be performed in the particular order shown or in a sequential order, or that all of the illustrated operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details have been included in the above discussion, these details should not be interpreted as limitations on the scope of this disclosure, but rather as descriptions of features that may be specific to a particular embodiment. Certain features described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, the various features that may be described in the context of a single embodiment may also be implemented in multiple embodiments in a separate manner or in any suitable subcombination.

[0182] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Instead, the specific features and acts described above may be disclosed as example forms of implementing the claims.

Claims

1. A first network device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the first network device to at least: Sending a first request message for selecting a network function for event subscription to the second network device, wherein the first request message includes event information to be subscribed; as well as A first response message is received from the second network device, the first response message including an identity of a selected network function of the plurality of network functions. 2 . The first network device of claim 1 , wherein the first request message comprises a Data Channel Signaling Function (DCSF) selection request, and the event subscription comprises a Data Channel (DC) event.

3. The first network device according to claim 1 or 2, wherein the first network device is further configured to: sending a second request message to the selected network function, the second request message being used to subscribe to an event at the selected network function; and A second response message is received from the selected network function, the second response message indicating success or failure of the subscription. 4 . The first network device according to claim 1 , wherein the first network device comprises a DC application server (DC AS).

5. The first network device according to any one of claims 1 to 3, wherein the first network device comprises a network open function (NEF), and the first network device is further caused to: A third request message for subscribing to an event and including the event information is received from a DC application server (DC AS), wherein the sending of the first request message is based on the receiving of the third request message.

6. The first network device according to claim 5, wherein the first network device is further configured to: Based on receiving the second response message from the selected network function, a third response message for the third request message is sent to the DC AS, wherein the third response message indicates success or failure of the subscription.

7. The first network device according to any one of claims 1 to 6, wherein the event information comprises at least one of the following: The name of the event; Type of event; the identity of one or more end devices; the identity of one or more applications to be subscribed to; or The location or area information of the terminal device being served.

8. The first network device according to any one of claims 1 to 7, wherein the identity of the selected network function comprises at least one of the following: Registered network capability profile; the address of the selected network function; or The unique identifier (ID) of the selected network function.

9. The first network device according to any one of claims 1 to 3, wherein the first network device is further configured to: receiving event subscription information from the selected network function when a subscribed event occurs; and Upon receiving the event subscription information, a fourth request message is sent to one or more network functions of the plurality of network functions, the fourth request message being for capability handling and including the identity of the selected network function.

10. The first network device of claim 9, wherein the first network device comprises a DC application server (DC AS).

11. The first network device of claim 9, wherein the first network device comprises a network open function (NEF), and the first network device is further caused to: receiving the identity of the selected network function from the selected network function; Sending the identity of the selected network function to a DC application server (DC AS) and simultaneously sending the event subscription information; and receiving a fourth request message from the DC AS, the fourth request message being for capability handling and including the identity of the selected network function, The sending of the fourth request message for capability handling and including the identity of the selected network function is based on the receiving of the fourth request message for capability handling and including the identity of the selected network function from the DC AS.

12. The first network device according to claim 4 or 10, wherein the DC AS is a trusted party.

13. The first network device according to any one of claims 5, 6 and 11, wherein the DC AS is a trusted party or an untrusted party. 14 . The first network device according to claim 10 , wherein when the event subscription information is received by the DC AS, the fourth request message for capability handling is triggered by the DC AS. 15 . The first network device of claim 12 , wherein the selected network function is determined by the DC AS based on the identity of the selected network function to process the fourth request message for capability handling. 16 . The first network device according to claim 13 , wherein, in a case where the DC AS is an untrusted party, the selected network function is determined by the NEF based on the identity of the selected network function to process the fourth request message for capability handling.

17. The first network device according to any one of claims 9 to 14, wherein the fourth request message for capability handling and including the identity of the selected network function is sent to an IP Multimedia Subsystem (IMS) network device through one or more network functions of the plurality of network functions.

18. The first network device of claim 17, wherein the selected network function is determined by the IMS network device based on the identity of the selected network function to process the fourth request message for capability handling.

19. A second network device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the second network device to at least: receiving, from a first network device, a first request message for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed; as well as A first response message is sent to the first network device, the first response message including an identity of a selected network function from among a plurality of network functions.

20. The second network device according to claim 19, wherein the second network device is further configured to: receiving, from the plurality of network functions, capability information for each of the plurality of network functions; registering each of the plurality of network functions using the capability information; and A second response message is sent to the plurality of network functions, where the second response message includes a result of the registration.

21. The second network device of claim 20, wherein the selected network function is selected based on the capability information and the event information.

22. The second network device according to any one of claims 19 to 21, wherein the selection request comprises a Data Channel Signalling Function (DCSF) selection request, and the event subscription comprises a Data Channel (DC) event.

23. The second network device according to any one of claims 19 to 22, wherein the capability information of the network function comprises at least one of the following: the identity of one or more terminal devices that the network function can serve; the identities of one or more applications that the network function can serve; Location or area information that the network function can serve; the types of events that the network function can service; or The specific events that the network function can service.

24. The second network device according to any one of claims 19 to 23, wherein the second network device comprises a Network Repository Function (NRF).

25. A third network device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the third network device to at least: receiving, from the first network device, a request message for capability handling and including an identity of a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process; as well as The selected network function is determined from the plurality of network functions based on the identity of the selected function to process the request message for capability handling.

26. The third network device of claim 25, wherein the third network device comprises an Internet Protocol Multimedia Subsystem Application Server (IMS AS).

27. A fourth network device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the fourth network device to at least: sending, to the second network device, capability information of the fourth network device for registration in the second network device; and A response message is received from the second network device, where the response message includes a result of the registration.

28. The fourth network device of claim 27, wherein the fourth network device comprises a Data Channel Signaling Function (DCSF).

29. A fourth network device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the fourth network device to at least: receiving, from a first network device, a request message for subscribing to an event at a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process, wherein the request message for subscribing to the event at the selected network function includes: an identity of the selected network function, and A response message is sent to the first network device, where the response message includes a result of the subscription.

30. The fourth network device of claim 29, wherein the fourth network device comprises the selected network function, the selected network function serving as a Data Channel Signaling Function (DCSF).

31. The fourth network device according to claim 29 or 30, wherein the fourth network device is further configured to: When a subscribed event occurs, sending event subscription information to the first network device; receiving, from the first network device, a request message for capability handling and including an identity of the selected network function; and The capability handling is processed.

32. A method for communication, comprising: Sending, through the first network device, a first request message for selecting a network function for event subscription to the second network device, wherein the first request message includes event information to be subscribed; as well as A first response message is received from the second network device by the first network device, the first response message including an identity of a selected network function from a plurality of network functions.

33. A method for communication, comprising: receiving, from the first network device through the second network device, a first request message for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed; as well as A first response message is sent by the second network device to the first network device, the first response message including an identity of a selected network function from among a plurality of network functions.

34. A method for communication, comprising: receiving, by the third network device, from the first network device a request message for capability handling including an identity of a selected network function, the selected network function being selected from the plurality of network functions during a network function selection process; as well as The selected function is determined, by the third network device, from the plurality of network functions based on the identity of the selected function to process the request message for capability handling.

35. A method for communication, comprising: sending, through the fourth network device, capability information of the fourth network device for registration in the second network device to the second network device; as well as A response message is received from the second network device through the fourth network device, where the response message includes a registration result.

36. A method for communication, comprising: receiving, by a fourth network device, from a first network device, a request message for subscribing to an event at a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process, wherein the request message for subscribing to the event at the selected network function includes: an identity of the selected network function; A response message is sent to the first network device through the fourth network device, where the response message includes a result of the subscription.

37. An apparatus for communication, comprising: means for sending a first request message for selecting a network function for event subscription to a second network device, wherein the first request message includes event information to be subscribed; as well as Means for receiving a first response message from the second network device, the first response message including an identity of a selected network function of the plurality of network functions.

38. An apparatus for communication, comprising: means for receiving, from a first network device, a first request message for selecting a network function for event subscription, wherein the first request message includes event information to be subscribed; as well as Means for sending a first response message to the first network device, the first response message including an identity of a selected network function of the plurality of network functions.

39. An apparatus for communication, comprising: means for receiving, from a first network device, a request message for capability handling and including an identity of a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process; as well as Means for determining the selected function from the plurality of network functions to process the request message for capability handling based on the identity of the selected function.

40. An apparatus for communication, comprising: a component configured to send, to a second network device, capability information of a fourth network device for registration in the second network device; as well as means for receiving a response message from the second network device, the response message including a result of the registration.

41. An apparatus for communication, comprising: means for receiving, from a first network device, a request message for subscribing to an event at a selected network function, the selected network function being selected from a plurality of network functions during a network function selection process, wherein the request message for subscribing to the event at the selected network function comprises: an identity of the selected network function, and A component for sending a response message to the first network device, wherein the response message includes a result of the subscription.

42. A non-transitory computer-readable medium comprising program instructions, which, when executed by an apparatus, cause the apparatus to at least perform the method according to any one of claims 32 to 36.

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