Method and apparatus for session restoration

Abstract

To provide a method and apparatus for session recovery.SOLUTION: A method performed by a network node, comprising: receiving from an application node a first request for setting up a session with a required Quality of Service (QoS); and sending to the application node a first response comprising error information and subscription information of an existing session, the subscription information comprising a subscription identifier.SELECTED DRAWING: Figure 2a

Description

[Technical Field]

[0001] Non-limiting and exemplary embodiments of the present disclosure relate generally to the field of communications, and more particularly to a method and apparatus for session restoration. [Background technology]

[0002] This section introduces aspects that may be helpful in improving the understanding of the disclosure. Accordingly, the statements in this section are to be read in this light and not understood as admissions about what is in the prior art or what is not in the prior art.

[0003] In communication networks such as LTE (Long Term Evolution) and NR (New Radio) defined by the 3rd Generation Partnership Project (3GPP®), application nodes such as third-party SCS / AS / AF (Service Capability Server / Application Server / Application Function) may require that data sessions to UEs (User Equipments) served by the application nodes be set up with a particular QoS (Quality of Service) (e.g., low latency or jitter) and with prioritized treatment. This capability may be exposed to the application nodes such as SCS / AS / AF via exposure nodes such as Service Capability Exposure Function (SCEF) and Network Exposure Function (NEF).

[0004] Section 5.11 of 3GPP® TS23.682 V17.0.0, the entire disclosure of which is incorporated herein by reference, describes the procedure for setting up an AS session with the required QoS. Section 4.15.6.6 of 3GPP® TS23.502 V17.0.0, the entire disclosure of which is incorporated herein by reference, describes the procedure for setting up an AF session with the required QoS procedures. Summary of the Invention [Problem to be solved by the invention]

[0005] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. It is understood that this Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claims.

[0006] The existing procedure for setting up an SCS / AS / AF session with the required QoS has several problems. For example, the SCS / AF / AS may experience loss of subscription data for ongoing QoS sessions due to unexpected issues such as a restart or reload of the SCS / AF / AS. Although the SCS / AF / AS can be recovered quickly, it cannot recover the complete QoS session subscription data, and ongoing QoS session subscription IDs are still lost. SCS / AF / AS restoration cannot be supported effectively. Duplicate session subscription data may result in redundant consumption of resources in network nodes (such as NEFs and other related NFs). The HTTP GET method for retrieving session subscription data carries the risk of placing a heavy signaling load on network nodes such as NEFs.

[0007] For example, when an SCS / AF / AS session with required QoS is requested by the AF / AS via the NEF / SCEF->PCF / PCRF (Policy Control Function / Policy and Charging Rules Function) and a specific QoS is requested to be applied in the network, appropriate configurations and resources are created in various network nodes such as the NEF / SCEF, PCF / PCRF, SMF (Session Management Function), UPF (User Plane Function), Packet Data Network Gateway (PGW), RAN (Radio Access Network), UE, etc., so that the user can enjoy better QoS (e.g., better bit rate, bandwidth, etc.). These resources are maintained in the relevant network elements and AF / AS and can be deleted when not needed (in this case, when they are not used by the UE).

[0008] For example, the QoS for a particular Internet Protocol (IP) flow (e.g., from a UE IP address to an AF IP address or vice versa) or application (identified by an application identifier) ​​is applied based on the QoS reference for the flow associated with the UE's IP address.

[0009] Loss of AF / AS QoS session subscription data can occur due to unexpected issues, such as an AF / AS restart or reload. Some customers have experienced the AF / AS (or an AF / AS of another party / vendor) losing ongoing sessions due to an AF / AS restart or reload. When the AF / AS recovers / reloads, if the UE is still receiving service (e.g., IP flows or application flows are still active), the AF / AS attempts to establish a new QoS session (via a Hypertext Transfer Protocol (HTTP) POST) to the NEF, separate from the existing QoS session. The QoS session-related information is sent to the PCF / PCRF and SMF / UPF / PGW, assuming that HTTP POSTs are, by definition, not idempotent (i.e., x HTTP POSTs result in x resources being created in the network). This means that the AF / AS may create new resources in the network when resources have already been created. In practice, the UPF / PGW may store multiple identical application flow or IP flow packet detection filter rules that are matched upon receiving an IP packet. However, only one of them is matched because packet detection matching stops when a packet matching the application flow or IP flow is received. This creates a large amount of duplicated resources in network nodes such as the NEF, PCF / PCRF, SMF, UPF, and PGW. Furthermore, packet matching in the UPF / PGW is performed according to priority, which may vary depending on the PCF / PCRF / SMF / UPF / PGW vendor. Therefore, when an application node such as an AF / AS establishes a new QoS session using partially or completely the same subscription data toward a network node such as an NEF / SCEF after the application node recovers, it is necessary to effectively identify and process the conflicting new session creation requests.

[0010] 3GPP TS29.122 V17.2.0, the entire disclosure of which is incorporated herein by reference, describes an HTTP GET method that allows reading all active subscriptions for a given SCS / AS. The SCS / AS initiates the HTTP GET request message, and the NEF / SCEF responds to the message. However, if an AF / AS needs to obtain only the QoS session subscription data of one or more specific UEs, rather than all active subscriptions of a specific SCS / AS, the HTTP GET method risks significantly impacting the signaling load. For example, obtaining all subscriptions risks signaling overload. The GET method for obtaining active session subscriptions by SCS / AS ID or AF ID only defines GET ALL, which risks significantly impacting the signaling load. If an AF only needs to obtain the QoS session subscription data of a specific UE without knowing each subscription ID, GET ALL also wastes additional subscription data processing costs for both the NEF and the AF. Therefore, it is necessary to effectively support obtaining the QoS session subscriptions of one or more specific UEs.

[0011] Ignoring new subscription requests risks contention and IoT issues. When AF / AS establishes new QoS session subscription requests to NEF / SCEF during AF / AS fast recovery and traffic from UE, blind new subscription requests without knowing whether an ongoing QoS session exists in the NEF risk consuming duplicate resources in the NEF and other related NFs in the EPC / 5GC (Evolved Packet Core / 5G Core Network), resulting in duplicate session subscriptions, and / or interworking compatibility issues due to the lack of clear handling definition in the current specifications.

[0012] To overcome or mitigate at least one of the above-mentioned problems or other problems, embodiments of the present disclosure propose an improved solution for session restoration. [Means for solving the problem]

[0013] In a first aspect of the present disclosure, there is provided a method performed by a network node, the method including receiving a first request from an application node to set up a session with a required quality of service (QoS), the method further including sending a first response to the application node including error information and subscription information for the existing session including a subscription identifier.

[0014] In one embodiment, the method further includes determining whether subscription data for the session established by the first request conflicts with subscription data for the existing session. The sending is performed if the subscription data for the session established by the first request conflicts with subscription data for the existing session.

[0015] In one embodiment, the determining is performed when the first request includes information indicating at least one of: checking whether subscription data of the session established by the first request conflicts with subscription data of an existing session; that a subscription check of the application node is requested; and that there is a potential conflict with an existing session.

[0016] In one embodiment, the error information includes an error status code and / or other error information.

[0017] In one embodiment, the subscription information for an existing session includes a link to a resource "Individual Application Session Subscription with Required QoS" that includes an existing subscription identifier.

[0018] In one embodiment, the subscription information for the existing session further includes existing subscription data for the existing session.

[0019] In one embodiment, the first response further includes at least one of: at least one QoS flow state of the existing session; and at least one notification event of the existing session.

[0020] In one embodiment, the QoS flow state includes at least one of active and inactive.

[0021] In one embodiment, the method further includes storing at least one QoS flow state of the existing session and / or at least one notification event of the existing session.

[0022] In one embodiment, storing at least one QoS flow state of the existing session and / or at least one notification event of the existing session includes storing at least one QoS flow state of the existing session and / or at least one notification event of the existing session if the application node supports session subscription checking.

[0023] In one embodiment, the first request further includes information indicating support for session subscription checking, and the first response further includes information indicating support for session subscription checking.

[0024] In one embodiment, the first request is an HTTP POST request and the first response is an HTTP POST response.

[0025] In one embodiment, the first request is received from the application node after the application node has restarted or reloaded.

[0026] In one embodiment, the network node comprises at least one of a publishing function node and a policy control node.

[0027] In one embodiment, the policy control node comprises at least one of a policy control function (PCF) and a policy and charging rules function (PCRF).

[0028] In one embodiment, the publishing function node comprises at least one of a Service Capability Publishing Function (SCEF), a Network Publishing Function (NEF), and a SCEF in combination with a NEF.

[0029] In one embodiment, the application node comprises at least one of an application function, an application server, and a service capability server.

[0030] In one embodiment, the method further includes receiving, from the application node, a second request to obtain subscription data for the application node, the second request including identities of one or more user equipment units (UEs). The method further includes transmitting, to the application node, a second response including one or more subscription data created by the application node corresponding to the identities of the one or more UEs.

[0031] In one embodiment, the UE identification information includes at least one of an Internet Protocol version 4 address of the UE, an Internet Protocol domain, an identifier of the UE, a MAC address of the UE, and an Internet Protocol version 6 address of the UE.

[0032] In one embodiment, the second response further includes at least one of: at least one QoS flow state corresponding to the subscription data; and at least one notification event corresponding to the subscription data.

[0033] In one embodiment, the second request is an HTTP GET request and the second response is an HTTP GET response.

[0034] In one embodiment, a second request is triggered for recovery.

[0035] In one embodiment, the second response includes the queried active subscriptions for the application node.

[0036] In a second aspect of the present disclosure, there is provided a method performed by a network node. The method includes receiving, from an application node, a second request to obtain subscription data for the application node. The second request includes identities of one or more user equipment units (UEs). The method further includes transmitting a second response to the application node, the second response including one or more subscription data created by the application node corresponding to the identities of the one or more UEs.

[0037] In a third aspect of the present disclosure, there is provided a method performed by an application node, the method including sending a first request to a publishing function node to set up a session with a required quality of service (QoS), the method further including receiving a first response from the publishing function node including error information and subscription information for the existing session including a subscription identifier.

[0038] In one embodiment, the receiving is performed if subscription data for the session established by the first request conflicts with subscription data for an existing session.

[0039] In one embodiment, the method further includes sending a second request to the network node to obtain subscription data of the application node, the second request including identities of one or more user equipment units (UEs), and receiving a second response from the network node including one or more subscription data created by the application node corresponding to the identities of the one or more UEs.

[0040] In a fourth aspect of the present disclosure, an application node The method includes transmitting a second request to a network node to obtain subscription data for the application node, the second request including identities of one or more user equipment units (UEs). The method further includes receiving a second response from the network node including one or more subscription data created by the application node corresponding to the identities of the one or more UEs.

[0041] In a fifth aspect of the present disclosure, there is provided a network node. The network node includes a processor and a memory coupled to the processor. The memory includes instructions executable by the processor. The network node is operative to receive a first request from an application node to set up a session with a required quality of service (QoS). The network node is further operative to send a first response to the application node, the first response including error information and subscription information for the existing session including a subscription identifier.

[0042] In one embodiment, the network node is further operative to check whether subscription data of the session established by the first request conflicts with subscription data of an existing session.

[0043] In one embodiment, the network node is further operative to store at least one QoS flow state of the existing session and / or at least one notification event of the existing session.

[0044] In one embodiment, the network node is further operable to receive a second request from the application node to obtain subscription data for the application node, the second request including identification information for one or more user equipment units (UEs).

[0045] In one embodiment, the network node is further operative to send a second response to the application node comprising one or more subscription data created by the application node corresponding to the identity of the one or more UEs.

[0046] In a sixth aspect of the present disclosure, there is provided a network node. The network node includes a processor and a memory coupled to the processor. The memory includes instructions executable by the processor. The network node is operative to receive a second request from the application node to obtain subscription data of the application node. The second request includes identification information of one or more user equipment units (UEs). The network node is further operative to send a second response to the application node including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0047] In a seventh aspect of the present disclosure, there is provided an application node. The application node includes a processor and a memory coupled to the processor. The memory includes instructions executable by the processor. The application node is operative to send a first request to the publishing function node to set up a session with a required quality of service (QoS). The application node is further operative to receive a first response from the publishing function node, the first response including error information and subscription information for the existing session, the subscription information including a subscription identifier.

[0048] In one embodiment, the application node is further operative to send a second request to the network node to obtain subscription data for the application node, the second request including identification information for one or more user equipment units (UEs).

[0049] In one embodiment, the application node is further operative to receive a second response from the network node, the second response including one or more subscription data created by the application node corresponding to the identity of the one or more UEs.

[0050] In an eighth aspect of the present disclosure, there is provided an application node. The application node includes a processor and a memory coupled to the processor. The memory includes instructions executable by the processor. The application node is operative to send a second request to the network node to obtain subscription data for the application node. The second request includes identification information for one or more user equipment units (UEs). The application node is further operative to receive a second response from the network node including one or more subscription data created by the application node corresponding to the identification information for the one or more UEs.

[0051] In a ninth aspect of the present disclosure, a network node is provided. The network node includes a first receiving module and a first transmitting module. The first receiving module may be configured to receive a first request to establish a session with a required quality of service (QoS) from an application node. The first transmitting module may be configured to send a first response to the application node, the first response including error information and subscription information of the existing session including a subscription identifier.

[0052] In one embodiment, the network node further includes a determining module configured to determine whether subscription data of the session established by the first request conflicts with subscription data of an existing session.

[0053] In one embodiment, the network node further comprises a storage module configured to store at least one QoS flow state of the existing session and / or at least one notification event of the existing session.

[0054] In one embodiment, the network node further comprises a second receiving module configured to receive a second request from the application node to obtain subscription data of the application node, the second request including identification information of one or more user equipment units (UEs).

[0055] In one embodiment, the network node further comprises a second sending module configured to send a second response to the application node, the second response including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0056] In a tenth aspect of the present disclosure, there is provided a network node, comprising: a second receiving module and a second sending module, the second receiving module configured to receive a second request from the application node to obtain subscription data of the application node, the second request including identification information of one or more user equipment units (UEs), and the second sending module configured to send a second response to the application node including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0057] In an eleventh aspect of the present disclosure, there is provided an application node, the application node comprising: a first sending module and a first receiving module, the first sending module configured to send a first request to establish a session with a required quality of service (QoS) to the publishing function node, and the first receiving module configured to receive a first response from the publishing function node, the first response including error information and subscription information of the existing session including a subscription identifier.

[0058] In one embodiment, the application node further includes a second sending module configured to send a second request to the network node to obtain subscription data for the application node, the second request including identification information of one or more user equipment units (UEs).

[0059] In one embodiment, the application node further comprises a second receiving module configured to receive from the network node a second response comprising one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0060] In a twelfth aspect of the present disclosure, there is provided an application node, the application node comprising: a second sending module and a second receiving module, the second sending module configured to send a second request to the network node to obtain subscription data of the application node, the second request including identification information of one or more user equipment units (UEs), and the second receiving module configured to receive a second response from the network node including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0061] In a thirteenth aspect of the present disclosure, there is provided a computer program product comprising instructions which, when executed by at least one processor, cause the at least one processor to perform a method according to any of the first, second, third and fourth aspects.

[0062] In a fourteenth aspect of the present disclosure, there is provided a computer-readable storage medium storing instructions which, when executed by at least one processor, cause the at least one processor to perform a method according to any of the first, second, third and fourth aspects.

[0063] Embodiments herein may provide many advantages, a non-exhaustive list of examples of which is provided below: The solution proposed in some embodiments herein may protect the core network from creating duplicate resources by network nodes (e.g., NEF / SCEF / PCF / PCRF) that implement conflict detection and provide accurate information to application nodes (e.g., AF / AS / SCS), thereby enabling conflict resolution based on needs / requirements and ensuring consistency of subscription information between application nodes and network nodes after an application node failure. The solution proposed in some embodiments herein may enable application nodes to quickly resynchronize / acquire their QoS sessions in the event of data failure / loss at the application node due to unexpected issues such as restart or reload. The solution proposed in some embodiments herein may avoid occupying extra resources at network nodes (e.g., NEF, PCF, SMF, UPF). The solution proposed in some embodiments herein may minimize signaling messages between application nodes and network nodes. The solution proposed in some embodiments herein may reduce AF QoS session recovery time by avoiding several new QoS session creation request messages. The embodiments herein are not limited to the preferred features and advantages described above, and those skilled in the art will recognize additional features and advantages upon reading the following detailed description.

[0064] The above and other aspects, features, and advantages of various embodiments of the present disclosure will become more fully apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which, by way of example, like or equivalent elements are designated by like reference numerals or characters, and in which the drawings are presented to facilitate a better understanding of the embodiments of the present disclosure and are not necessarily drawn to scale. [Brief explanation of the drawings]

[0065] [Figure 1a]FIG. 1 illustrates a schematic diagram of a high-level architecture of a fifth generation network according to an embodiment of the present disclosure. [Figure 1b] FIG. 1 illustrates a schematic diagram of a 4G network system architecture according to an embodiment of the present disclosure. [Figure 2a] 1 is a flowchart of a method according to an embodiment of the present disclosure. [Figure 2b] 4 is a flowchart of a method according to another embodiment of the present disclosure. [Figure 3] 4 is a flowchart of a method according to another embodiment of the present disclosure. [Figure 4] 4 is a flowchart of a method according to another embodiment of the present disclosure. [Figure 5] 4 is a flowchart of a method according to another embodiment of the present disclosure. [Figure 6] 4 is a flowchart of a method according to another embodiment of the present disclosure. [Figure 7] 10 is a flowchart of AF QoS session recovery according to an embodiment of the present disclosure. [Figure 8] 10 is a flowchart of AF QoS session recovery according to another embodiment of the present disclosure. [Figure 9] 10 is a flowchart of AF QoS session recovery according to another embodiment of the present disclosure. [Figure 10] 10 is a flowchart of AF QoS session recovery according to an embodiment of the present disclosure. [Figure 11] 10 is a flowchart of AF QoS session recovery according to another embodiment of the present disclosure. [Figure 12] 10 is a flowchart of AF QoS session recovery according to another embodiment of the present disclosure. [Figure 13] FIG. 1 is a block diagram illustrating an apparatus suitable for implementing some embodiments of the present disclosure. [Figure 14] FIG. 2 is a block diagram illustrating a network node according to an embodiment of the present disclosure. [Figure 15] FIG. 10 is a block diagram illustrating a network node according to another embodiment of the present disclosure. [Figure 16] FIG. 2 is a block diagram illustrating an application node according to an embodiment of the present disclosure. [Figure 17] FIG. 10 is a block diagram illustrating an application node according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0066] Embodiments of the present disclosure will now be described in detail with reference to the drawings. It should be understood that these embodiments are not intended to imply any limitation on the scope of the present disclosure, but are described solely to enable those skilled in the art to better understand and therefore practice the present disclosure. Throughout this specification, references to features, advantages, or similar language do not imply that all features and advantages that may be realized in the present disclosure should or are present in any single embodiment of the present disclosure. Rather, language referring to features and advantages is understood to mean that a particular feature, advantage, or characteristic described in connection with one embodiment is included in at least one embodiment of the present disclosure. Furthermore, the features, advantages, and characteristics described in the present disclosure can be combined in any suitable manner in one or more embodiments. Those skilled in the relevant art will recognize that the present disclosure may be practiced without one or more of the specific features or advantages of a particular embodiment. In other examples, additional features and advantages may be recognized in certain embodiments that are not present in all embodiments of the present disclosure.

[0067] As used herein, the term "network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced, Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and other wireless networks. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA). UTRA includes WCDMA and other variants of CDMA. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA network may implement wireless technologies such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, ad hoc networks, wireless sensor networks, etc. In the following description, the terms "network" and "system" may be used interchangeably. Furthermore, communication between two devices in a network may be performed according to any suitable communication protocol, including, but not limited to, communication protocols defined by standards organizations such as 3GPP®. For example, communication protocols may include first generation (1G), 2G, 3G, 4G, 4.5G, 5G communication protocols, and / or other protocols now known or developed in the future.

[0068] The term "network device" or "network node" refers to any suitable network function (NF) that may be implemented in a network function (physical or virtual) of a communications network. For example, a network function may be implemented as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on a suitable platform, such as a cloud infrastructure. For example, a 5G system (5GS) may include multiple NFs, such as an AMF (Access and Mobility Function), an SMF (Session Management Function), an AUSF (Authentication Service Function), an UDM (Unified Data Management), a PCF (Policy Control Function), an AF (Application Function), an NEF (Network Publishing Function), an UPF (User Plane Function), an NRF (Network Repository Function), a RAN (Radio Access Network), an SCP (Service Communication Proxy), an NWDAF (Network Data Analysis Function), an NSSF (Network Slice Selection Function), and an NSSAAF (Network Slice Specific Authentication and Authorization Function). For example, a 4G system (such as LTE) may include an MME (Mobility Management Entity), an HSS (Home Subscriber Server), a Policy and Charging Rules Function (PCRF), a Packet Data Network Gateway (PGW or PG-W), a PGW Control Plane (PGW-C), a Serving Gateway (SGW), an SGW Control Plane (SGW-C), an E-UTRAN Node B (eNB), etc. In other embodiments, the network nodes may include different types of NFs, depending, for example, on the particular network.

[0069] The term "terminal device" or "user equipment (UE)" refers to any end device that can access a communications network and receive service. By way of non-limiting example, a terminal device may refer to a mobile terminal or other suitable device. A UE may be, for example, a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). A terminal device may include, but is not limited to, a portable computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and playback device, a mobile phone, a cellular phone, a smartphone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet, a wearable device, a personal digital assistant (PDA), a portable computer, a desktop computer, a wearable terminal device, an in-vehicle wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded equipment (LEE), a laptop mounted equipment (LME), a USB dongle, a smart device, a wireless customer premises equipment (CPE), etc. In the following description, the terms "terminal device," "terminal," "user equipment," and "UE" may be used interchangeably. As an example, a terminal device may represent a UE configured to communicate in accordance with one or more communications standards promulgated by 3GPP (Third Generation Partnership Project), e.g., the 3GPP LTE or NR standards. As used herein, "user equipment" or "UE" does not necessarily have a "user" in the sense of a human user who owns and / or operates the associated device. In some embodiments, a terminal device may be configured to transmit and / or receive information without direct human interaction. For example, a terminal device may be designed to transmit information to a network on a predetermined schedule, in response to a request from the communications network, when triggered by an internal or external event, or when connected to a network. Alternatively, a UE may represent a device intended for sale to or operation by a human user, but not initially associated with a specific human user.

[0070] As yet another example, in an Internet of Things (IoT) scenario, a terminal device may represent an appliance or other device that performs monitoring and / or measurements and transmits results of such monitoring and / or measurements to another terminal device and / or network equipment. In this case, the terminal device is a machine-to-machine (M2M) device, which may be referred to in the 3GPP context as a machine-type communication (MTC) device. As a particular example, the terminal device may be a UE implementing the 3GPP Narrowband IoT (NB-IoT) standard. Specific examples of such appliances or devices are metering devices such as sensors, power meters, industrial machines, or household appliances such as refrigerators, televisions, and personal wearable appliances such as watches. In other scenarios, the terminal device may represent a vehicle or other appliance that can monitor and / or report its operating state or other functions related to its operation.

[0071] References herein to "one embodiment," "embodiment," "example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described with respect to an embodiment, implementing such feature, structure, or characteristic in connection with other embodiments is presented as being within the knowledge of one of ordinary skill in the art, whether or not explicitly stated.

[0072] As used herein, terms such as "first" and "second" may be used to describe various elements, but it should be understood that these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed terms.

[0073] As used herein, the phrase "at least one of A and B" or "at least one of A or B" should be understood to mean "A only, B only, or both A and B." The phrase "A and / or B" should be understood to mean "A only, B only, or both A and B."

[0074] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. The singular forms "a," "an," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. As used herein, the terms "including," "having," "comprising," and the like specify the presence of stated features, elements, and / or components, but do not exclude the presence of one or more other features, elements, components, and / or combinations thereof.

[0075] Please note that these terms used in this document are only used for ease of explanation and to distinguish between nodes, devices, networks, etc. As technology develops, other terms with similar / same meanings may also be used.

[0076] In the following description and claims, unless defined otherwise, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0077] Although the subject matter described herein may be implemented in any suitable type of system using any suitable components, the embodiments disclosed herein are described with reference to a communication system conforming to the exemplary system architecture shown in Figures 1a and 1b. For simplicity, the system architecture of Figures 1a and 1b shows only a few example elements. In practice, the communication system may further include any additional elements suitable for supporting communications between terminal devices, or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or terminal device. The communication system may provide communications and various types of services to one or more terminal devices to facilitate the terminal device's access to and / or use of services provided by or through the communication system.

[0078] FIG. 1a schematically illustrates a high-level architecture of a fifth-generation network according to an embodiment of the present disclosure. For example, the fifth-generation network may be a 5GS. The architecture of FIG. 1a is the same as FIG. 4.2.3-1 described in 3GPP TS23.501 V17.0.0, the entire contents of which are incorporated herein by reference. The system architecture of FIG. 1a may include several exemplary elements, such as an AUSF, an AMF, a DN (Data Network), a NEF, an NRF, an NSSF, a PCF, an SMF, a UDM, a UPF, an AF, a UE, an (R)AN, an SCP (Service Communication Proxy), an NSSAAF (Network Slice Specific Authentication and Authorization Function), and an NSACF (Network Slice Admission Control Function).

[0079] According to an exemplary embodiment, as shown in Figure 1a, a UE can establish a signaling connection with the AMF via reference point N1. This signaling connection enables NAS (Non-Access Stratum) signaling exchange between the UE and the core network and includes a signaling connection between the UE and the (R)AN and an N2 connection for this UE between the (R)AN and the AMF. The (R)AN can communicate with the UPF via reference point N3. The UE can establish a protocol data unit (PDU) session to a DN (data network, e.g., operator network or the Internet) through the UPF via reference point N6.

[0080] As further shown in Figure 1a, the exemplary system architecture also includes service-based interfaces, such as Nnrf, Nnef, Nausf, Nudm, Npcf, Namf, Nnsacf, and Nsmf, provided by NFs, such as NRF, NEF, AUSF, UDM, PCF, AMF, NSACF, and SMF. Additionally, Figure 1a also shows several reference points, such as N1, N2, N3, N4, N6, and N9, that can support interactions between NF services within the NFs. For example, these reference points can be realized by specifying several NF service consumers and providers and their interactions to perform specific system procedures via corresponding NF service-based interfaces.

[0081] The various NFs shown in FIG. 1a may be responsible for functions such as session management, mobility management, authentication, security, etc. The AUSF, AMF, DN, NEF, NRF, NSSF, PCF, SMF, UDM, UPF, AF, UE, (R)AN, SCP, and NSACF may include functions defined, for example, in section 6.2 of 3GPP TS23.501 V17.0.0.

[0082] Figure 1b schematically illustrates a system architecture of a 4G network according to an embodiment of the present disclosure, which is identical to Figure 4.2-2 of 3GPP TS23.682 V17.0.0, the disclosure of which is incorporated herein by reference in its entirety. The system architecture of Figure 1b may include several exemplary elements, such as a Service Capability Server (SCS), an Application Server (AS), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), a Mobile Management Entity / Serving General Packet Radio Service (GPRS) Support Node (MME / SGSN), a Policy and Charging Rules Function (PCRF), a Serving Call Server Control Function (S-CSCF), a Radio Congestion Awareness Function (RCAF), a Packet Flow Description Function (PFDF), a Broadcast Multicast Service Center (BM-SC), and other network entities. The network elements and interfaces illustrated in Figure 1b may be identical to the corresponding network elements and interfaces described in 3GPP TS23.682 V17.0.0.

[0083] 2a is a flowchart of a method according to one embodiment of the present disclosure, which may be performed in an apparatus implemented in a network node, or in a network node, or by an apparatus communicatively connected to a network node. Thus, the apparatus may provide means or modules for accomplishing various parts of method 200 and means or modules for accomplishing other processes together with other components.

[0084] A network node may be a physical entity or a virtualized network function, for example, a network node may be any suitable network device, node, entity, or function (physical or virtual) that is capable of providing the functionality for setting up a session with the required QoS.

[0085] In one embodiment, the network node may comprise at least one of a publishing node and a policy control node.

[0086] An exposing node may be a physical entity or a virtualized network function. For example, an exposing node may be any suitable network device, node, entity, or function (physical or virtual) that can provide a means to securely expose the services and capabilities offered by its network interface. An exposing node may provide a means for discovering the exposed services and capabilities. An exposing node may provide access to network capabilities through a homogenous network application programming interface (e.g., a network API). An exposing node may abstract services from the underlying network interface and protocols.

[0087] In one embodiment, the publishing node comprises at least one of a Service Capabilities Publishing Function (SCEF), a Network Publishing Function (NEF), and a SCEF in combination with a NEF.

[0088] A policy control node may be any suitable network device, node, entity, or function (physical or virtual) capable of providing policy control functionality. For example, a policy control node may support a unified policy framework for managing network operation. The policy control node may provide policy rules to a control plane function to enforce the policy rules. The policy control node may access subscription information related to policy decisions in a data repository.

[0089] In one embodiment, the policy control node may comprise at least one of a policy control function (PCF) and a policy and charging rules function (PCRF).

[0090] At block 202, the network node may receive a first request from an application node to set up a session with a required quality of service (QoS).

[0091] An application node may be a physical entity or a virtualized network function. For example, an application node may be any suitable network device, node, entity, or function (physical or virtual) that can interact with a network (such as a 3GPP® core network) to provide services. For example, an application node may support application influence on traffic routing. An application node may support access to network exposed functions. An application node may support interaction with a policy framework for policy control. Based on deployment at the operator, application nodes that are deemed trusted by the operator may be allowed to interact directly with associated network functions. Application nodes that are not allowed by the operator to directly access network functions use an external exposed framework via an exposed node such as the NEF / SCEF to interact with associated network functions.

[0092] In one embodiment, the application node may comprise at least one of an application function (AF), an application server (AS), and a service capability server (SCS).

[0093] The first request may be any suitable request. In one embodiment, the first request may be a Nnef_AFsessionWithQoS_Create request as described in section 4.15.6.6 of 3GPP TS 23.502 V17.0.0. In another embodiment, the first request may be an On-Demand QoS Request message as described in section 5.11 of 3GPP TS 23.682 V17.0.0. In another embodiment, the first request may be received via an Rx interface and may trigger a PCRF-initiated IP-CAN (IP Connectivity Access Network) session modification as described in section 7.4.2 of 3GPP TS 23.203 V17.1.0, the disclosure of which is incorporated herein by reference in its entirety.

[0094] In one embodiment, the first request is an HTTP POST request.

[0095] In one embodiment, the first request includes information indicating at least one of checking whether subscription data for the session established by the first request conflicts with subscription data for an existing session, that an application node subscription check is requested, and a potential conflict with an existing session. The information may take any suitable form, such as an indication, a bit, a flag, etc. In one embodiment, the information may be an attribute name, such as "subCheckInd." The data type of the attribute name may be a Boolean value or other suitable data type. If the attribute name is included and set to true, the attribute name indicates that an SCS / AF / AS session subscription check is requested.

[0096] In one embodiment, the first request includes information indicating support for session subscription checking. The information may take any suitable form, such as an indication, a bit, a flag, etc. In one embodiment, the information may be a feature, such as "SubscriptionCheck," which indicates support for SCS / AF / AS session subscription checking. In other embodiments, the support for session subscription checking feature may be included in any other suitable message. In this embodiment, the network node can know whether the application node supports session restoration.

[0097] In one embodiment, the first request is received from the application node after the application node has been restarted or reloaded.

[0098] At block 206, the network node may send a first response to the application node that includes the error information and subscription information of the existing session, including the subscription identifier.

[0099] In one embodiment, if the subscription data of the session established by the first request conflicts with the subscription data of the existing session, the network node may send a first response to the application node including error information and the subscription information of the existing session including the subscription identifier.

[0100] The first response may be any appropriate response. In one embodiment, the first response may be a Nnef_AFsessionWithQoS_Create response as described in section 4.15.6.6 of 3GPP TS23.502 V17.0.0. In another embodiment, the first response may be an On-Demand QoS Response message as described in section 5.11 of 3GPP TS23.682 V17.0.0. In another embodiment, the first response may be sent over the Rx interface as described in section 7.4.2 of 3GPP TS23.203 V17.1.0.

[0101] In one embodiment, the first response is an HTTP POST response.

[0102] In one embodiment, the first response includes information indicating support for session subscription checking. The information may take any suitable form, such as an indication, a bit, a flag, etc. In one embodiment, the information may be a feature such as "SubscriptionCheck." This feature indicates support for SCS / AF / AS session subscription checking. In other embodiments, the feature of support for session subscription checking may be included in any other suitable message. In this embodiment, the application node can know whether the network node supports session subscription checking.

[0103] In one embodiment, the error information includes an error status code and / or other error information. The error status code may be any appropriate error status code. The error status code may indicate that the subscription request (i.e., the first request) conflicted with an existing QoS session subscription or was not processed due to another client error (e.g., syntax error). In one embodiment, the error status code may be a Hypertext Transfer Protocol (HTTP) 409 Conflict Status Code. In one embodiment, the error status code may be an HTTP 409 Bad Request status code. In one embodiment, the error status code may be an HTTP 303 etc. see status code. In other embodiments, the error status code may be any other appropriate HTTP status code.

[0104] In one embodiment, the subscription information of the existing session includes a link to the resource "Individual Application Session Subscription with Required QoS" that contains the existing subscription identifier. For example, if the subscription data of the session established by the first request conflicts with an existing QoS session subscription, the network node should return the existing subscription data and include a "self" attribute that includes a link to the resource "Individual AS Session Subscription with Required QoS" that contains the existing subscription ID. The "self" attribute may be the same as the "self" attribute described in Table 5.14.2.1.2-1 of 3GPP TS29.122 V17.2.0.

[0105] In one embodiment, the subscription information for the existing session further includes existing subscription data for the existing session.

[0106] In one embodiment, the first response further includes at least one of: at least one QoS flow state of the existing session; and at least one notification event of the existing session.

[0107] In one embodiment, the QoS flow state includes at least one of active and inactive.

[0108] 2b is a flowchart of another method according to an embodiment of the present disclosure, which may be performed in an apparatus implemented in a network node, or in the network node, or by an apparatus communicatively connected to the network node. Thus, the apparatus may provide means or modules for achieving various parts of the method 220 and means or modules for achieving other processes together with other components. For the sake of brevity, detailed descriptions of some parts described in the above embodiments will be omitted here.

[0109] A network node may receive a first request to set up a session with a required quality of service (QoS) from an application node in block 202. Block 202 is the same as block 202 in FIG.

[0110] At block 204, the network node may determine (or check) whether subscription data for the session established by the first request conflicts with subscription data for an existing session. For example, if the session established by the first request conflicts with an existing session (e.g., partially or completely the same subscription data), the network node may determine that the subscription data for the session established by the first request conflicts with the subscription data of the existing session. The network node may perform the determining operation unconditionally or conditionally. In one embodiment, the determining (or checking) operation is performed when the first request includes information indicating at least one of: checking whether subscription data for the session established by the first request conflicts with subscription data for the existing session; that a subscription check of the application node is requested; and that there is a potential conflict with the existing session.

[0111] The network node may send a first response to the application node, the first response including the error information and the subscription information of the existing session, including the subscription identifier, in block 206. Block 206 is the same as block 206 in FIG. 2a.

[0112] According to various embodiments, the proposed solution introduces a new feature negotiated between the application node and the network node to make the application node, such as the AF / AS, aware of conflicts between subscription data for the session established in the first request and subscription data for existing sessions. In response to the first request containing an indication of a potential conflict with an existing session or other similar information, the network node, such as the NEF, operates in a specific manner. For example, the network node, such as the NEF, checks whether the requested subscription conflicts with one of the existing QoS session subscription data in the network node. If there is a conflict, the network node rejects the new subscription request and returns a new conflict error to the application node containing the existing QoS session subscription data created / updated by the application node.

[0113] 3 is a flowchart of a method according to another embodiment of the present disclosure, which may be performed in an apparatus implemented in a network node, or in the network node, or by an apparatus communicatively connected to the network node. Thus, the apparatus may provide means or modules for accomplishing various parts of the method 300 and means or modules for accomplishing other processes together with other components. For the sake of brevity, detailed descriptions of some parts described in the above embodiments will be omitted here.

[0114] At block 302, the network node may store at least one QoS flow state of an existing session and / or at least one notification event of an existing session. The network node may unconditionally or conditionally store the at least one QoS flow state of an existing session and / or the at least one notification event of the existing session.

[0115] In one embodiment, a network node may store the at least one QoS flow state of the existing session and / or the at least one notification event of the existing session if the application node supports session subscription checking or QoS session restoration. For example, the application node may send a message to a network node including information indicating that it supports session subscription checking or QoS session restoration, after which the network node may know that the application node supports session subscription checking or QoS session restoration.

[0116] The network node may keep track of QoS flow states (e.g., deactivated QoS flows) and / or notified event reports of existing QoS sessions. When the network node notifies the application node about a conflict, the network node may also send at least one QoS flow state of the existing session and / or at least one notified event of the existing session. For example, the network node may send information about which flows are active / inactive and / or which events of which flows have been reported for an existing QoS session. In this way, the application node has complete information to internally reconstruct the QoS session: the requested QoS session data and the current QoS is applied.

[0117] 4 is a flowchart of a method according to another embodiment of the present disclosure, which may be performed in an apparatus implemented in a network node, or in the network node, or by an apparatus communicatively connected to the network node. Thus, the apparatus may provide means or modules for achieving various parts of the method 400 and means or modules for achieving other processes together with other components. For the sake of brevity, detailed descriptions of some parts described in the above embodiments will be omitted here.

[0118] At block 402, the network node may receive a second request from the application node to obtain subscription data for the application node. The second request includes one or more user equipment (UE) identities. The second request may be an HTTP GET request as described in section 5.14.3.2.3.1 of 3GPP TS29.122 V17.2.0, except that the second request further includes one or more UE identities.

[0119] The identity of the one or more UEs may be any suitable information that can be used to identify the one or more UEs, for example, the identity of the UE may be an identifier or a UE address (such as an IP address or a MAC (Medium Access Control) address).

[0120] In one embodiment, the UE identification information includes at least one of an Internet Protocol (IP) version 4 (IPv4) address of the UE, an Internet Protocol domain, a UE identifier, a UE MAC address, and an Internet Protocol version 6 address of the UE. The UE identifier may be any suitable identifier that can uniquely identify the UE within the network. For example, the UE identifier may be an internal identifier used within the network or an external identifier used outside the network. For example, the Internet Protocol domain may be an IPv4 address domain identifier. The Internet Protocol domain is only provided if an IPv4 address is included in the ip-addrs query parameter.

[0121] At block 404, the network node may send a second response to the application node that includes one or more subscription data created by the application node that corresponds to the identification information of the one or more UEs.

[0122] In one embodiment, the second response further includes at least one of: at least one QoS flow state corresponding to the subscription data; and at least one notification event corresponding to the subscription data.

[0123] In one embodiment, the second request is an HTTP GET request and the second response is an HTTP GET response.

[0124] In one embodiment, the second request is triggered for recovery. For example, an application node may trigger a request related to recovery. In one embodiment, the second request is received from an application node after the application node is restarted or reloaded.

[0125] In one embodiment, the second response includes the queried active subscriptions for the application node, for example, the second response includes one or more subscription data created by the application node corresponding to one or more identities of the UE for the application node, or the queried active subscriptions for the given SCS / AS.

[0126] According to various embodiments, the proposed solution provides an application node, such as an AF, with the option to proactively retrieve QoS session subscription data with subscription IDs (identifiers) from all ongoing QoS sessions. In this way, only QoS session subscription data related to one or more UE identities is sent to the application node. The application node may send the second message before attempting an IP flow or application flow.

[0127] 5 is a flowchart of a method according to another embodiment of the present disclosure, which may be performed in an apparatus implemented in an application node, or in the application node, or by an apparatus communicatively connected to the application node. Thus, the apparatus may provide means or modules for accomplishing various parts of the method 500 and means or modules for accomplishing other processes together with other components. For the sake of brevity, detailed descriptions of some parts described in the above embodiments will be omitted here.

[0128] In block 502, the application node may send a first request to the publishing function node to set up a session with a required quality of service (QoS). The first request is the same as that described in the above embodiment.

[0129] In block 504, the application node may receive a first response from the publishing function node, the first response including error information and subscription information of the existing session, including the subscription identifier. In one embodiment, the application node may receive the first response when subscription data of the session established by the first request conflicts with subscription data of the existing session. The first response is the same as that described in the above embodiment.

[0130] After receiving the first response, the application node knows the error information and can restore the subscription data based on the received subscription information of the existing session, which includes the subscription identifier.

[0131] 6 is a flowchart of a method according to another embodiment of the present disclosure, which may be performed in an apparatus implemented in an application node, or in the application node, or by an apparatus communicatively connected to the application node. Thus, the apparatus may provide means or modules for accomplishing various parts of the method 600 and means or modules for accomplishing other processes together with other components. For the sake of brevity, detailed descriptions of some parts described in the above embodiments will be omitted here.

[0132] In block 602, the application node may send a second request to the network node to obtain subscription data for the application node. The second request includes identification information of one or more user equipments (UEs). The second request is the same as that described in the above embodiment.

[0133] In block 604, the application node may receive a second response from the network node, the second response including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs. The second response may be the same as that described in the above embodiment.

[0134] FIG. 7 is a flowchart of AF QoS session restoration according to an embodiment of the present disclosure.

[0135] Step 1: The AF sends an AF session creation request with QoS (e.g., request 1) to the NEF. The request may include the UE's IP address, a QoS reference, IP flow 1 - audio, IP flow 2 - video, and a new feature: AF restoration support. In one embodiment, the AF restoration support may be information indicating support for a session subscription check or subCheckInd, as described above.

[0136] Step 2: The NEF sends an Npcf_PolicyAuthorization_Request to the PCF. The Npcf_PolicyAuthorization_Request may include the UE's IP address, AF app ID, IP flow 1 - audio, and IP flow 2 - video.

[0137] Step 3: QoS flow is established: The UE has an ongoing QoS session to the UE (the IP address of the UE) for the audio-video session.

[0138] Step 4: The PCF sends an Npcf_PolicyAuthorization_Response (success) to the NEF.

[0139] Step 5: The NEF sends a Create AF Session with QoS response (e.g., a first response) to the AF. The Create AF Session with QoS response may include the UE's IP address, a QoS reference, IP flow 1 - audio, IP flow 2 - video, and a new feature: AF restoration capability. In one embodiment, the AF restoration capability may be information indicating support for a session subscription check or subCheckInd, as described above.

[0140] Step 6: The AF session (eg, subscription data of the AF session) is stored by the NEF and the AF.

[0141] Steps 8 to 14 pertain to Scenario 1. QoS continues to be applied to all IP flows.

[0142] Step 8: AF may be restarted or reloaded for various reasons.

[0143] Step 9: AF QoS session information is lost.

[0144] Step 10: The AF does not remember anything and attempts to create the session as a new session when it receives traffic from the UE. The AF includes an indication that the session may conflict with a previous session, so the NEF checks whether there is an overlapping or conflicting session. For example, when the AF receives traffic from the UE, the AF may request an AS session subscription request with a new QoS that includes an indication that the NEF checks whether the subscription request conflicts with an existing QoS session subscription in the NEF.

[0145] Step 11: The AF sends an AF session creation request with QoS (e.g., a first request) to the NEF. The request may include the UE's IP address, a QoS reference, IP flow 1 - audio, IP flow 2 - video, new function: AF restoration enabled, and new: unreliable indication (or AF failure indication, subscription check-in indication, session check-in indication, subscription and session check, or other appropriate indication). In one embodiment, the unreliable indication may be information indicating at least one of checking whether subscription data of the session established by the first request conflicts with subscription data of an existing session, that a subscription check of the application node is required, and a potential conflict with an existing session.

[0146] Step 12: The NEF checks whether there is an existing session for the AF associated with the same UE IP address and at least one flow already exists. In this case, a QoS session is found for the UE IP address and two IP flows. Re-synchronization with the AF is triggered by rejecting the request and including the data necessary for the AF to reconstruct the lost session.

[0147] Step 13: The NEF sends a Create AF Session with QoS response to the AF. The Create AF Session with QoS response may include: NEW:Error Indication, QoS Reference, IP Flow 1 - Audio, NEW:State=Active, IP Flow 2 - Video, NEW:State=Active, NEW:AF Restore Supported.

[0148] Step 14: The AF restores the subscription information and QoS flow state.

[0149] 8 is a flowchart of AF QoS session restoration according to another embodiment of the present disclosure. In this embodiment, QoS is not applied to all IP flows (e.g., video QoS flows are reset to default QoS). FIG. 8 may also include steps 1-6 of FIG. 7.

[0150] Step 16: The video QoS flow is deactivated while the AF QoS session continues.

[0151] Step 17: The PCC rule is removed from the AF session.

[0152] Step 18: The PCF sends an Npcf_PolicyAuthorization_Notify to the NEF. The Npcf_PolicyAuthorization_Notify may include IP Flow 2 - Video, Event = Resource Allocation Failure.

[0153] Step 19: Because the AF indicated support for AF restoration, the NEF stores the QoS flow state. The QoS flow continues to be part of the AF session because it was originally requested by the AF, but its state is set to disabled, meaning that the requested QoS will not be applied to the video flow.

[0154] Step 20: The NEF sends an AF Session Notification with QoS to the AF. The AF Session Notification with QoS may include: IP Flow 2 - Video, Event = Resource Allocation Failure.

[0155] Step 21: The AF may be restarted or reloaded for various reasons.

[0156] Step 22: The AF QoS session information is lost.

[0157] Step 23: The AF does not remember anything and attempts to create the session as a new session when it receives traffic from the UE. The AF includes an indication that the session may conflict with a previous session, so the NEF checks whether there is an overlapping or conflicting session. For example, when the AF receives traffic from the UE, the AF may request an AS session subscription request with a new QoS that includes an indication that the NEF checks whether the subscription request conflicts with an existing QoS session subscription in the NEF.

[0158] Step 24: The AF sends an AF session creation request with QoS (e.g., a first request) to the NEF. The request may include the UE IP address, the QoS reference, IP flow 1 - audio, IP flow 2 - video, new function: AF restoration supported, and a NEW unreliable indication. In one embodiment, the unreliable indication may be information indicating at least one of checking whether subscription data of the session established by the first request conflicts with subscription data of an existing session, requesting a subscription check of the application node, and a potential conflict with an existing session.

[0159] Step 25: Since the AF includes an untrusted indication, the NEF checks whether there is an existing session for the AF associated with the same UE IP address and at least one flow already exists. In this case, a QoS session for the UE IP address is found. Re-synchronization with the AF is triggered by rejecting the request.

[0160] Step 26: The NEF sends a Create AF Session with QoS response to the AF. The Create AF Session with QoS response may include: NEW:Error Indication, QoS Reference, IP Flow 1 - Audio, NEW:State=Active, IP Flow 2 - Video, NEW:State=Inactive, NEW:AF Restoration Supported.

[0161] Step 27: The AF restores the subscription information and QoS flow state. Furthermore, the AF may retry establishing the video QoS by updating the session.

[0162] Step 28: The AF sends an AS session update request with QoS to the NEF. The AS session update request with QoS may include the UE's IP address, a QoS reference, and IP flow 2-video.

[0163] Step 29: The NEF may send an Npcf_PolicyAuthorization_UpdateRequest to the PCF. The Npcf_PolicyAuthorization_UpdateRequest may include the UE's IP address, the AF app ID, and IP flow 2—video.

[0164] Step 30: Since QoS flow 1 is already established, only QoS flow 2 is retried.

[0165] 9 is a flowchart of AF QoS session restoration according to another embodiment of the present disclosure. In this embodiment, when UE traffic is detected after the AF is restarted or reloaded, the AF acquires a QoS session from the NEF. FIG. 9 may also include steps 1 to 6 of FIG. 7.

[0166] Step 32: The AF may be restarted or reloaded for various reasons.

[0167] Step 33: The AF QoS session information is lost.

[0168] Step 34: Instead of attempting a new session request after an AF failure, the AF decides to first check whether a session already exists and the state of the flow. For example, if the AF can obtain the UE ID or UE address during or before traffic from the UE, the AF can send a GET query including the UE ID or UE address to the NEF to obtain the UE's existing session including QoS subscription data. If the NEF returns the UE's subscription data including the subscription ID in a GET response message and the AF can successfully restore the QoS session, the AF does not need to send a new subscription request and can omit the related procedures.

[0169] Step 35: The AF sends a GET request for all AF sessions with QoS (e.g., a second request) to the NEF. The GET request for all AF sessions with QoS may include new query parameters: UE IP address, and new function: AF restoration support.

[0170] Step 36: Because the AF requested an existing QoS session that matches the UE's IP address, the NEF finds an ongoing session that matches the new criteria. The NEF returns the QoS session created by the AF. Because the AF supports the new AF restoration feature, the NEF returns the flow state. Otherwise, the NEF includes only the subscription data for the session.

[0171] Step 37: The NEF sends a GET response for all AF sessions with QoS to the AF. The GET response for all AF sessions with QoS may include: QoS Reference, IP Flow 1 - Audio, New: State = Active, IP Flow 2 - Video, New: State = Inactive, New Feature: AF Restoration Supported.

[0172] Step 38: The AF restores the subscription information and the QoS flow state.

[0173] In this embodiment, the GET method is enhanced by supporting GET queries with the UE ID or UE address to minimize the impact of signaling overload compared to GET ALL.

[0174] 10 is a flowchart of AF QoS session restoration according to another embodiment of the present disclosure, in which the AF directly connects to and interacts with the PCF.

[0175] Step 1: The AF sends an Npcf_PolicyAuthorization_Request to the PCF. The Npcf_PolicyAuthorization_Request may include the UE's IP address, AF app ID, IP flow 1 - audio, IP flow 2 - video, and new feature: AF restore support. In one embodiment, the AF restore support may be information indicating support for session subscription check or subCheckInd, as described above.

[0176] Step 2: QoS flow is established: The UE has an ongoing QoS session to the UE (the IP address of the UE) for an audio-video session.

[0177] Step 3: PCF sends Npcf_PolicyAuthorization_Response (success, new feature: AF restoration supported) to AF.

[0178] Step 4: The AF session (eg, subscription data of the AF session) is stored by the PCF and the AF.

[0179] Steps 6 to 12 pertain to Scenario 1. QoS continues to be applied to all IP flows.

[0180] Step 6: AF may be restarted or reloaded for various reasons.

[0181] Step 7: AF QoS session information is lost.

[0182] Step 8: The AF does not remember anything and attempts to create the session as a new session when it receives traffic from the UE. The AF includes an indication that the session may conflict with a previous session, so the PCF checks for the existence of overlapping or conflicting sessions. For example, when the AF receives traffic from the UE, the AF may request an AS session subscription request with a new QoS that includes an indication that the PCF checks whether the subscription request conflicts with an existing QoS session subscription in the PCF.

[0183] Step 9: The AF sends an Npcf_PolicyAuthorization_Request to the PCF. The Npcf_PolicyAuthorization_Request may include the UE's IP address, AF App ID, IP Flow 1 - Audio, IP Flow 2 - Video, New Feature: AF Restoration Supported, and New: Untrusted Indication. In one embodiment, the untrusted indication may be information indicating at least one of checking whether subscription data of the session established by the first request conflicts with subscription data of an existing session, that a subscription check of the application node is required, and a potential conflict with an existing session.

[0184] Step 11: The PCF checks whether there is an existing session for the AF associated with the same UE IP address and at least one flow already exists. In this case, a QoS session is found for the UE IP address and two IP flows. Re-synchronization with the AF is triggered by rejecting the request and including the data necessary for the AF to re-establish the lost session.

[0185] Step 11: PCF sends Npcf_PolicyAuthorization_Response(Error Indication, AF App ID, IP Flow 1 - Audio, New: State = Active, IP Flow 2 - Video, New: State = Active, New Feature: AF Restore Supported) to AF.

[0186] Step 12: The AF restores the subscription information and QoS flow state.

[0187] 11 is a flowchart of AF QoS session restoration according to another embodiment of the present disclosure. In this embodiment, the AF directly connects to and interacts with the PCF. In this embodiment, QoS is not applied to all IP flows (e.g., video QoS flows are reset to default QoS). FIG. 11 may also include steps 1-4 of FIG. 10.

[0188] Step 14: The video QoS flow is deactivated while the AF QoS session continues.

[0189] Step 15: The PCC rule is removed from the AF session.

[0190] Step 16: The PCF sends an Npcf_PolicyAuthorization_Notify to the AF. The Npcf_PolicyAuthorization_Notify may include IP Flow 2 - Video, Event = Resource Allocation Failure.

[0191] Step 17: Because the AF has indicated support for the AF restoration feature, the PCF stores the QoS flow state. The QoS flow state continues to be maintained as part of the AF session because it was originally requested by the AF, but the state is set to invalid, meaning that the requested QoS will not be applied to the video flow.

[0192] Step 18: The AF may be restarted or reloaded for various reasons.

[0193] Step 19: The AF QoS session information is lost.

[0194] Step 20: The AF does not remember anything and will attempt to create the session as a new session when it receives traffic from the UE. The AF will include an indication that the session may conflict with a previous session, so the PCF will check whether there is an overlapping or conflicting session. For example, when the AF receives traffic from the UE, the AF may request a new AS session subscription request with QoS, which includes an indication for the PCF to check whether the subscription request conflicts with an existing QoS session subscription in the NEF.

[0195] In step 21, the AF sends an Npcf_PolicyAuthorization_Request to the PCF. The Npcf_PolicyAuthorization_Request may include the UE's IP address, AF App ID, IP Flow 1 - Audio, IP Flow 2 - Video, New Feature: AF Restoration Supported, and New: Untrusted Indication. In one embodiment, the untrusted indication may be information indicating at least one of checking whether subscription data of the session established by the first request conflicts with subscription data of an existing session, that a subscription check of the application node is required, and a potential conflict with an existing session.

[0196] Step 22: Since the AF includes an untrusted indication, the PCF checks whether there is an existing session for the AF associated with the same UE IP address and at least one flow already exists. In this case, a QoS session is found for the UE IP address. Re-synchronization with the AF is triggered by rejecting the request.

[0197] Step 23: The PCF sends Npcf_PolicyAuthorization_Response(Error Indication, IP Flow 1 - Audio, New: State = Active, IP Flow 2 - Video, New: State = Inactive, New Feature: AF Restoration Supported) to the AF.

[0198] Step 24: The AF restores the subscription information and QoS flow state, and may retry establishing the video QoS by updating the session.

[0199] Step 25: The AF sends an Npcf_PolicyAuthorization_Update to the PCF. The Npcf_PolicyAuthorization_Update may include the UE's IP address, the AF app ID, and IP flow 2 - video.

[0200] Step 26: Since QoS flow 1 is already established, only QoS flow 2 is retried.

[0201] 12 is a flowchart of AF QoS session restoration according to another embodiment of the present disclosure. In this embodiment, the AF directly connects to the PCF and interacts with the PCF. In this embodiment, when UE traffic is detected after the AF is restarted or reloaded, the AF acquires the QoS session from the PCF. FIG. 12 may also include steps 1 to 4 of FIG. 10.

[0202] Step 28: The AF may be restarted or reloaded for various reasons.

[0203] Step 29: The AF QoS session information is lost.

[0204] Step 30: Instead of attempting a new session request after an AF failure, the AF decides to first check whether a session already exists and the state of the flow. For example, if the AF can obtain the UE ID or UE address during or before traffic from the UE, the AF can send a GET query including the UE ID or UE address to the PCF to obtain the UE's existing session including QoS subscription data. If the PCF returns the UE's subscription data including the subscription ID in a GET response message and the AF can successfully restore the QoS session, the AF does not need to send a new subscription request and can omit the related procedures.

[0205] Step 31: The AF sends an all application context session GET request to the PCF, where the all application context session GET request may include a new query parameter: the IP address of the UE, and a new function: AF restore support.

[0206] Step 32: Because the AF requested an existing application context session that matches the UE's IP address, the PCF finds an ongoing session that matches the new criteria. The PCF returns the QoS session created by the AF. Because the AF supports the new AF restoration feature, the PCF returns the flow state. Otherwise, the PCF includes only the subscription data for the session.

[0207] Step 33: The PCF sends an All Application Context Sessions GET response to the AF. The All Application Context Sessions GET response may include: IP Flow 1 - Audio, New: State = Active, IP Flow 2 - Video, New: State = Inactive, New Feature: AF Restore Supported.

[0208] The AF restores the subscription information and QoS flow state.

[0209] In this embodiment, the GET method is enhanced by supporting GET queries with the UE ID or UE address to minimize the impact of signaling overload compared to GET ALL.

[0210] In one embodiment, we propose a Get query subscription to minimize the impact of signaling overload. The GET method to retrieve active session subscriptions per SCS / AS ID or AF ID can be extended to support an optional query UE address to minimize the impact of signaling load, and meets the AF requirement only when subscription data for a specific UE's QoS sessions needs to be retrieved without knowledge of each subscription ID, to avoid wasting processing costs on both the NEF and AF for unnecessary subscription data.

[0211] In one embodiment, a subscription check is proposed to avoid overlap and IoT issues. A solution is proposed to enhance the AF / AS and NEF / SCEF to support subscription check functions, indicators, and procedures when the AF / AS establishes a new QoS session subscription request to the NEF / SCEF upon AF / AS fast recovery and traffic from the UE.

[0212] In one embodiment, the AF / AS and NEF / SCEF support a subscription check function. If the AF / AS does not know whether a new session subscription request conflicts with an existing session or whether an existing session subscription ID is missing, the AF / AS may send a subscription check indicator in the subscription request.

[0213] In one embodiment, upon receiving a subscription check indicator in a subscription request from an AF / AS, the NEF / SCEF matches the new subscription request with existing QoS session subscriptions, and if a conflict is identified, the NEF / SCEF does not process the new session request, but instead returns an error code (400 Bad Request is considered appropriate) in the response message body along with the subscription data (including the existing subscription ID) of the matching, conflicting existing AS session, effectively restoring the corresponding AS session with QoS.

[0214] The reason for considering 400 Bad Request is that RFC7231 relaxes the 400 (Bad Request) status code to not be limited to syntax errors, but to include any situation where the server cannot or will not process the request for any reason that is considered a client error, which is suitable to avoid duplicate AS session creation with minimal impact to the NEF / SCEF and AF / AS, and also supports extensions to the response body to return subscriptions for existing QoS sessions, including their respective subscription IDs and resource links.

[0215] In one embodiment, the following may be added to section 4.4.13 of 3GPP TS29.122 V17.2.0: To create the initial AS session, the SCS / AS sends an HTTP POST message to the SCEF for the "AS Session Subscription with Required QoS" resource. The body of the HTTP POST message may include the SCS / AS identifier, the UE's IP address, a description of the IP flow, a QoS reference, and a notification address. It may also include the duration and traffic volume intended for the sponsored data connection. If the AppId feature is supported, either the flow description or the external application identifier is included. If the SubscriptionCheck feature is supported, the SCS / AS may include a subCheckInd attribute that instructs the SCEF to check whether the AS session subscription request conflicts with an existing AS session subscription. If the subCheckInd attribute is included in the HTTP POST message, the SCEF shall check whether the requested subscription data is included in the subscription of an existing AS session. If a conflict is identified, no new subscription is created. The SCEF shall respond to the SCS / AS with a 400 error status code and the returned complete existing AS session including the QoS subscription data shall include a "self" attribute containing a link to the resource "Individual AS Session Subscription with the desired QoS" containing the existing subscription ID. If no conflict is identified, the SCEF shall continue processing the steps described below.

[0216] In one embodiment, the following may be added to Table 5.14.2.1.2-1 of 3GPP TS29.122 V17.2.0: [Table 1]

[0217] In one embodiment, the following may be added to Table 5.14.3.2.3.1-2 of 3GPP TS29.122 V17.2.0: [Table 2]

[0218] In one embodiment, the following may be added to Table 5.14.3.2.3.4-2 of 3GPP TS29.122 V17.2.0: [Table 3]

[0219] In one embodiment, the following is added to Table 5.14.4-1 of 3GPP TS29.122 V17.2.0: m may be any suitable number, such as 11. [Table 4]

[0220] Embodiments herein may provide many advantages, a non-exhaustive list of examples of which is provided below: The solution proposed in some embodiments herein may protect the core network from creating duplicate resources by network nodes (e.g., NEF / SCEF / PCF / PCRF) that implement conflict detection and provide accurate information to application nodes (e.g., AF / AS / SCS), thereby enabling conflict resolution based on needs / requirements and ensuring consistency of subscription information between application nodes and network nodes after an application node failure. The solution proposed in some embodiments herein may enable application nodes to quickly resynchronize / acquire their QoS sessions in the event of data failure / loss at the application node due to unexpected issues such as restart or reload. The solution proposed in some embodiments herein may avoid occupying extra resources at network nodes (e.g., NEF, PCF, SMF, UPF). The solution proposed in some embodiments herein may minimize signaling messages between application nodes and network nodes. The solution proposed in some embodiments herein may reduce AF QoS session recovery time by avoiding several new QoS session creation request messages. The embodiments herein are not limited to the preferred features and advantages described above, and those skilled in the art will recognize additional features and advantages upon reading the following detailed description.

[0221] 13 is a block diagram illustrating an apparatus suitable for implementing some embodiments of the present disclosure. For example, the application nodes or network nodes described above may be implemented as or via apparatus 1300.

[0222] The apparatus 1300 comprises at least one processor 1321, such as a digital processor (DP), and at least one memory (MEM) 1322 coupled to the processor 1321. The apparatus 1300 may further comprise a transmitter TX and a receiver RX 1323 coupled to the processor 1321. The MEM 1322 stores a program (PROG) 1324. The PROG 1324 may include instructions that, when executed by an associated processor 1321, enable the apparatus 1300 to operate according to embodiments of the present disclosure. The combination of the at least one processor 1321 and the at least one MEM 1322 may form a processing means 1325 adapted to perform various embodiments of the present disclosure.

[0223] Various embodiments of the present disclosure may be implemented by a computer program executable by one or more of the processor(s) 1321, software, firmware, hardware, or combinations thereof.

[0224] MEM1322 may be of any type suitable for the local technology environment and may be implemented using any suitable data storage technology, such as, by way of non-limiting example, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed and removable memory, etc.

[0225] The processor 1321 may be of any type suitable for the local technology environment and may include, by way of non-limiting example, 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.

[0226] In embodiments in which the apparatus is implemented as a network node, the memory 1322 includes instructions executable by the processor 1321 to cause the network node to operate according to any of the methods associated with the network nodes described above.

[0227] In embodiments in which the device is implemented as an application node, memory 1322 includes instructions executable by processor 1321 to cause the application node to operate according to any of the methods associated with application nodes described above.

[0228] 14 is a block diagram illustrating a network node according to an embodiment of the present disclosure. As shown, the network node 1400 includes a first receiving module 1401 and a first transmitting module 1402. The first receiving module 1401 may be configured to receive a first request from the application node to establish a session with a required quality of service (QoS). The first transmitting module 1402 may be configured to send a first response to the application node, the response including error information and subscription information of the existing session, including a subscription identifier.

[0229] In one embodiment, the network node 1400 further includes a determining module 1403 configured to determine whether subscription data of the session established by the first request conflicts with subscription data of an existing session.

[0230] In one embodiment, the network node 1400 further includes a storage module 1404 configured to store at least one QoS flow state of the existing session and / or at least one notification event of the existing session.

[0231] In one embodiment, the network node 1400 further comprises a second receiving module 1405 configured to receive a second request from the application node to obtain subscription data of the application node, the second request including identification information of one or more user equipment units (UEs).

[0232] In one embodiment, the network node 1400 further comprises a second sending module 1406 configured to send a second response to the application node including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0233] 15 is a block diagram illustrating a network node according to another embodiment of the present disclosure. As shown, the network node 1500 includes a second receiving module 1501 and a second sending module 1502. The second receiving module 1501 is configured to receive a second request from the application node to obtain subscription data of the application node, the second request including identification information of one or more user equipment units (UEs). The second sending module 1502 is configured to send a second response to the application node including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0234] 16 is a block diagram illustrating an application node according to an embodiment of the present disclosure. As shown, the application node 1600 includes a first sending module 1601 and a first receiving module 1602. The first sending module 1601 is configured to send a first request to establish a session with a required quality of service (QoS) to the publishing function node. The first receiving module 1602 is configured to receive a first response from the publishing function node, the first response including error information and subscription information for the existing session, the subscription information including a subscription identifier.

[0235] In one embodiment, the application node 1600 further includes a second sending module 1603 configured to send a second request to the network node to obtain subscription data for the application node, the second request including identification information for one or more user equipment units (UEs).

[0236] In one embodiment, the application node 1600 further comprises a second receiving module 1604 configured to receive a second response from the network node including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0237] 17 is a block diagram illustrating an application node according to another embodiment of the present disclosure. As shown, the application node 1700 includes a second sending module 1701 and a second receiving module 1702. The second sending module 1701 is configured to send a second request to the network node to obtain subscription data of the application node, the second request including identification information of one or more user equipment units (UEs). The second receiving module 1702 is configured to receive a second response from the network node including one or more subscription data created by the application node corresponding to the identification information of the one or more UEs.

[0238] The term unit has its conventional meaning in the fields of electricity, electrical devices, and / or electronic devices and may include, for example, electrical and / or electronic circuits, devices, modules, processors, memories, logical solid state and / or discrete devices, computer programs or instructions described herein for performing respective tasks, procedures, calculations, output, and / or display functions, etc.

[0239] By using the functional unit, the network node or application node does not need a fixed processor or memory, and any computing resource and storage resource can be allocated from the network node or application node in the communication system. The introduction of virtualization technology and network computing technology can improve the utilization efficiency of network resources and the flexibility of the network.

[0240] According to one aspect of the present disclosure, there is provided a computer program product comprising instructions tangibly stored on a computer-readable storage medium and that, when executed on at least one processor, cause the at least one processor to perform any of the methods set forth above.

[0241] According to one aspect of the present disclosure, there is provided a computer-readable storage medium storing instructions that, when executed by at least one processor, cause the at least one processor to perform any of the methods set forth above.

[0242] The present disclosure further provides a carrier comprising a computer program as described above, the carrier being one of an electrical signal, an optical signal, a radio signal or a computer-readable storage medium, which may be, for example, an optical compact disc or an electronic memory device such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, a magnetic tape, a CD-ROM, a DVD, a Blu-ray disc, etc.

[0243] The techniques described herein may be implemented by various means, and an apparatus implementing one or more functions of a corresponding apparatus described in the embodiments may have not only conventional means but also means for implementing one or more functions of the corresponding apparatus described in the embodiments, which may include separate means for each separate function, or means that may be configured to perform one or more functions. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. In the case of firmware or software, the implementation may be realized by modules (e.g., procedures, functions, etc.) that perform the functions described herein.

[0244] The exemplary embodiments herein have been described above with reference to block diagrams and flowcharts of methods and apparatuses. It will be understood that each block of the block diagrams and flowchart diagrams, and combinations of blocks in each of the block diagrams and flowchart diagrams, can be implemented by various means, including computer program instructions. These computer program instructions can be loaded into a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce machine-generated instructions that execute on the computer or other programmable data processing apparatus to create means for implementing the function specified in the flowchart block or block.

[0245] Additionally, although acts are described in a particular order, there is no requirement that they be performed in the particular order shown or in sequential order, as all described acts may be performed to achieve desirable results. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although the above description includes some specific implementation details, these do not limit the scope of the disclosure, and description of features may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0246] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of the implementation or claimed subject matter, but rather as descriptions of functionality specific to particular embodiments of a particular implementation. Certain features described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable subcombination. Furthermore, while features may be described above as working in a particular combination, and may even initially be claimed as such, one or more features from a claimed combination may, in some cases, be deleted from that combination, and the claimed combination may be directed to subcombinations or variations of the subcombination.

[0247] It will be obvious to those skilled in the art that, as technology advances, the concept of the present invention can be implemented in various ways. The above-described embodiments are given to illustrate, not to limit, the present disclosure, and it should be understood that modifications and variations can be resorted to without departing from the spirit and scope of the present disclosure, as easily understood by those skilled in the art. Such modifications and variations are deemed to be within the scope of the present disclosure and the appended claims. The scope of protection of the present disclosure is defined by the appended claims.

Claims

1. A method (200) performed by a network node, comprising: receiving (202) a first request from an application node to set up a session with a required Quality of Service (QoS); sending (206) a first response to the application node, the first response including error information and subscription information of the existing session including a subscription identifier; A method comprising:

2. 10. The method of claim 1 further comprising: determining (204) whether subscription data for the session established by the first request conflicts with subscription data for an existing session; The method, wherein the sending is performed if the subscription data for the session established by the first request conflicts with the subscription data for the existing session.

3. 3. The method of claim 2, verifying that subscription data for the session established by the first request conflicts with subscription data for an existing session; Application node subscription checks are required, Potential conflicts with existing sessions and wherein the determining is performed if the first request includes information indicative of at least one of:

4. 4. The method according to any one of claims 1 to 3, The method, wherein the error information includes an error status code and / or other error information.

5. 5. The method according to any one of claims 1 to 4, The method of claim 1, wherein the subscription information of the existing session includes a link to a resource "Individual Application Session Subscription with Required QoS" that includes an existing subscription identifier.

6. The method of claim 5 , wherein the subscription information for the existing session further comprises existing subscription data for the existing session.

7. 7. The method of any one of claims 1 to 6, The first response may further include: at least one QoS flow state of the existing session; and at least one notification event for the existing session; The method includes at least one of:

8. 8. The method of claim 7, The method, wherein the QoS flow state includes at least one of active and inactive.

9. 9. The method of claim 7 or 8, further comprising: Storing (302) the at least one QoS flow state of the existing session and / or the at least one notification event of the existing session.

10. 10. The method of claim 9, wherein storing the at least one QoS flow state of the existing session and / or the at least one notification event of the existing session comprises, if the application node supports session subscription checking, storing the at least one QoS flow state of the existing session and / or the at least one notification event of the existing session.

11. 11. The method of any one of claims 1 to 10, the first request includes information indicating support for session subscription checking; The method, wherein the first response further includes information indicating support for session subscription checking.

12. 12. The method of any one of claims 1 to 11, the first request is an HTTP POST request; The method, wherein the first response is an HTTP POST response.

13. 13. The method of any one of claims 1 to 12, The method, wherein the first request is received from the application node after the application node has been restarted or reloaded.

14. 14. The method of any one of claims 1 to 13, The network node a public function node; a policy control node; The method includes at least one of:

15. 15. The method of claim 14, The policy control node a Policy Control Function (PCF); and a Policy and Charging Rules Function (PCRF); and The method includes at least one of:

16. 16. The method of claim 15, wherein the public function node: A Service Capabilities Exposure Function (SCEF); Network Publish Function (NEF); SCEF combined with NEF, The method includes at least one of:

17. 17. The method of any one of claims 1 to 16, The application node Application features and an application server; a service capability server; The method includes at least one of:

18. 18. The method of any one of claims 1 to 17, further comprising: receiving (402) a second request from the application node to obtain subscription data for the application node, the second request including identification information of one or more user equipment units (UEs); sending (404) a second response to the application node, the second response including one or more subscription data created by the application node corresponding to the identities of one or more UEs; A method comprising:

19. 20. The method of claim 18, The identification information of the UE is an Internet Protocol version 4 address of the UE; and an internet protocol domain; an identifier of the UE; and a Medium Access Control (MAC) address of the UE; and an Internet Protocol version 6 address of the UE; and The method includes at least one of:

20. 20. The method of claim 18 or 19, The second response may further include: at least one QoS flow state corresponding to the subscription data; at least one notification event corresponding to the subscription data; The method includes at least one of:

21. 21. The method of any one of claims 18 to 20, the second request is an HTTP GET request; The method, wherein the second response is an HTTP GET response.

22. 22. The method of any one of claims 18 to 21, The second request is triggered for recovery.

23. 23. The method of any one of claims 18 to 22, comprising: The second response includes active subscriptions queried for the application node.

24. A method (400) performed by a network publishing node, comprising: receiving (402) a second request from the application node to obtain application node subscription data, the second request including identification information of one or more user equipment units (UEs); sending (404) a second response to the application node, the second response including one or more subscription data created by the application node corresponding to the identities of one or more UEs; A method comprising:

25. 25. The method of claim 24, The UE identification information is an Internet Protocol version 4 address of the UE; and an internet protocol domain; an identifier of the UE; and a MAC address of the UE; and an Internet Protocol version 6 address of the UE; and The method includes at least one of:

26. 26. The method of claim 24 or 25, The second response may further include: at least one QoS flow state corresponding to the subscription data; at least one notification event corresponding to the subscription data; The method includes at least one of:

27. 27. The method of any one of claims 24 to 26, comprising: the second request is an HTTP GET request; The method, wherein the second response is an HTTP GET response.

28. 28. The method of any one of claims 24 to 27, comprising: The network node a public function node; a policy control node; The method includes at least one of:

29. 29. The method of claim 28, The policy control node a Policy Control Function (PCF); and a Policy and Charging Rules Function (PCRF); and The method includes at least one of:

30. 30. The method of claim 28 or 29, The public function node A Service Capabilities Exposure Function (SCEF); Network Publish Function (NEF); SCEF combined with NEF, The method includes at least one of:

31. 31. The method of any one of claims 24 to 30, comprising: The application node Application features and an application server (AS); a service capability server (SCS); The method includes at least one of:

32. 32. The method of any one of claims 24 to 31, comprising: The second request is triggered for recovery.

33. 33. The method of any one of claims 24 to 32, comprising: The second response includes active subscriptions queried for the application node.

34. A method (500) performed by an application node, comprising: Sending (502) a first request to set up a session with a required Quality of Service (QoS) to a public function node; receiving (504) a first response from the publishing function node, the first response including error information and subscription information for the existing session including a subscription identifier; A method comprising:

35. 35. The method of claim 34, The method, wherein the receiving is performed when subscription data for the session established by the first request conflicts with subscription data for the existing session.

36. 36. The method of claim 34 or 35, The first request is: verifying that subscription data for the session established by the first request conflicts with subscription data for an existing session; Application node subscription checks are required, Potential conflicts with existing sessions and The method includes information indicative of at least one of:

37. 37. The method of any one of claims 34 to 36, comprising: The method, wherein the error information includes an error status code and / or other error information.

38. 38. The method of any one of claims 34 to 37, comprising: The method of claim 1, wherein the subscription information of the existing session includes a link to a resource "Individual Application Session Subscription with Required QoS" that includes an existing subscription identifier.

39. 39. The method of claim 38, The method, wherein the subscription information for the existing session further includes existing subscription data for the existing session.

40. 36. The method of any one of claims 34 to 35, The first request may further include: at least one QoS flow state of the existing session; and at least one notification event for the existing session; The method includes at least one of:

41. 37. The method of claim 36, The method, wherein the QoS flow state includes at least one of active and inactive.

42. 42. The method of any one of claims 34 to 41, comprising: the first request includes information indicating support for session subscription checking; The method, wherein the first response further includes information indicating support for session subscription checking.

43. 43. The method of any one of claims 34 to 42, comprising: the first request is an HTTP POST request; The method, wherein the first response is an HTTP POST response.

44. 44. The method of any one of claims 34 to 43, comprising: The method of claim 1, wherein the first request is sent to the network node after the application node is restarted or reloaded.

45. 45. The method of any one of claims 34 to 44, comprising: The network node a public function node; a policy control node; The method includes at least one of:

46. 46. ​​The method of claim 45, The policy control node a Policy Control Function (PCF); and a Policy and Charging Rules Function (PCRF); and The method includes at least one of:

47. 46. ​​The method of claim 45, The public function node A Service Capabilities Exposure Function (SCEF); Network Publish Function (NEF); SCEF combined with NEF, The method includes at least one of:

48. 48. The method of any one of claims 34 to 47, comprising: The application node Application features and an application server; a service capability server; The method includes at least one of:

49. 49. The method of any one of claims 34 to 48, further comprising: sending a second request to the network node for obtaining subscription data for the application node, the second request including identification information of one or more user equipment units (UEs); receiving (604) a second response from the network node, the second response including one or more subscription data created by the application node corresponding to the identities of one or more UEs; A method comprising:

50. 50. The method of claim 49, wherein the identity of the UE is: an Internet Protocol version 4 address of the UE; and an internet protocol domain; an identifier of the UE; and a MAC address of the UE; and an Internet Protocol version 6 address of the UE; and The method includes at least one of:

51. 51. The method of claim 49 or 50, The second response may further include: at least one QoS flow state corresponding to the subscription data; at least one notification event corresponding to the subscription data; The method includes at least one of:

52. 52. The method of any one of claims 49 to 51, comprising: the second request is an HTTP GET request; The method, wherein the second response is an HTTP GET response.

53. 53. The method of any one of claims 49 to 52, comprising: The second request is triggered for recovery.

54. 54. The method of any one of claims 49 to 53, comprising: The second response includes active subscriptions queried for the application node.

55. A method (600) performed by an application node, comprising: sending a second request to a network node to obtain subscription data for the application node, the second request including identification information of one or more user equipment units (UEs); receiving (604) a second response from the network node, the second response including one or more subscription data created by the application node corresponding to the identities of one or more UEs; A method comprising:

56. 56. The method of claim 55, The UE identification information is an Internet Protocol version 4 address of the UE; and an internet protocol domain; an identifier of the UE; and a MAC address of the UE; and an Internet Protocol version 6 address of the UE; and The method includes at least one of:

57. 57. The method of claim 55 or 56, The second response may further include: at least one QoS flow state corresponding to the subscription data; at least one notification event corresponding to the subscription data; The method includes at least one of:

58. 58. The method of any one of claims 55 to 57, the second request is an HTTP GET request; The method, wherein the second response is an HTTP GET response.

59. 59. The method of any one of claims 55 to 58, comprising: The network node a public function node; a policy control node; The method includes at least one of:

60. 60. The method of claim 59, The policy control node a Policy Control Function (PCF); and a Policy and Charging Rules Function (PCRF); and The method includes at least one of:

61. 61. The method of claim 59 or 60, The public function node A Service Capabilities Exposure Function (SCEF); Network Publish Function (NEF); SCEF combined with NEF, The method includes at least one of:

62. 62. The method of any one of claims 55 to 61, comprising: The application node Application features and an application server; a service capability server; The method includes at least one of:

63. 63. The method of any one of claims 55 to 62, comprising: The second request is triggered for recovery.

64. 64. The method of any one of claims 55 to 63, comprising: The second response includes active subscriptions queried for the application node.

65. A network node (1300), A processor (1321); a memory (1322) coupled to the processor (1321); wherein the memory (1322) contains instructions executable by the processor (1321), such that the network node (1300) receiving a first request from an application node to set up a session with a required quality of service (QoS); sending a first response to the application node, the first response including error information and subscription information of the existing session including a subscription identifier; A network node that operates to perform the following:

66. 58. A network node according to claim 57, comprising: The network node is further operative to perform a method according to any one of claims 2 to 21.

67. A network publishing node (1300), A processor (1321); a memory (1322) coupled to the processor (1321); The memory (1322) includes instructions executable by the processor (1321), whereby the network publishing node (1300) receiving a second request from the application node to obtain application node subscription data, the second request including identification information of one or more user equipment units (UEs); sending a second response to the application node, the second response including one or more subscription data created by the application node corresponding to the identification information of one or more UEs; A network publishing node that acts as a

68. 68. A network publishing node as claimed in claim 67, comprising: The network publishing node is further operative to perform a method according to any one of claims 25 to 33.

69. An application node (1300), A processor (1321); a memory (1322) coupled to the processor (1321); wherein the memory (1322) contains instructions executable by the processor (1321), such that the application node (1300) sending a first request to a public function node to set up a session with a required Quality of Service (QoS); receiving a first response from the publishing function node, the first response including error information and subscription information of the existing session including a subscription identifier; An application node that operates as follows.

70. 70. An application node as claimed in claim 69, comprising:

55. An application node, the application node further operative to perform a method according to any one of claims 35 to 54.

71. An application node (1300), A processor (1321); a memory (1322) coupled to the processor (1321); wherein the memory (1322) contains instructions executable by the processor (1321), such that the application node (1300) sending a second request to a network node to obtain subscription data for the application node, the second request including identification information of one or more user equipment units (UEs); receiving a second response from the network node, the second response including one or more subscription data created by the application node corresponding to the identities of one or more UEs; An application node that operates as follows.

72. 72. An application node according to claim 71, comprising:

65. An application node, the application node further operative to perform a method according to any one of claims 56 to 64.

73. A computer-readable storage medium storing instructions that, when executed on at least one processor, cause the at least one processor to perform the method of any one of claims 1 to 64.

74. 65. A computer program comprising instructions which, when executed on at least one processor, cause said at least one processor to perform the method of any one of claims 1 to 64.

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