Radio access network node, core network node, and methods for these

Abstract

A radio access network (RAN) node according to the present invention receives, from a core network, a QoS (quality of service) profile for a packet flow. When the RAN node transmits, to the core network, a notification indicating that a QoS profile is no longer satisfied or will be satisfied again while maintaining the packet flow without releasing the packet flow or without refusing to set up or correct the packet flow, the RAN node also notifies the core network of the reason, the cause, or a factor which led to the determination that the QoS profile is no longer satisfied or will be satisfied again. This contributes to an improvement in control of notifications between a RAN and a core network.

Description

Radio access network node, core network node, and methods thereof

[0001] The present disclosure relates to wireless communication systems, and more particularly to signaling between a radio access network and a core network.

[0002] The 3rd Generation Partnership Project (3GPP) Release 15 and later releases specify notification control (see, for example, Section 5.7.2.4 of Non-Patent Document 1 and Section 8.2.4 of Non-Patent Document 2). Notification control is also called Quality of Service (QoS) notification control (QNC). Notification control enables the core network to receive notifications from the Radio Access Network (RAN) when the Guaranteed Flow Bit Rate (GFBR) can no longer (or can again) be guaranteed for a Guaranteed Flow Bit Rate (GBR) QoS flow.

[0003] The QoS profile of a QoS flow can be provided to the RAN by the core network. Specifically, the Session Management Function (SMF) in the core network provides the QoS profile to the RAN via the Access and Mobility Management Function (AMF) in the core network. A QoS flow can be either "GBR" or "non-GBR" depending on its QoS profile. The QoS profile includes multiple QoS parameters. For each QoS flow, the QoS profile includes a 5G QoS Identifier (5QI) and an Allocation and Retention Priority (ARP). Additionally, for each GBR QoS flow, the QoS profile includes a Guaranteed Flow Bit Rate (GFBR) and a Maximum Flow Bit Rate (MFBR). Furthermore, for each GBR QoS flow, the QoS profile may include a notification control. Note that, when a standardized 5QI value is used, the 5QI value defines static values ​​for the Packet Delay Budget (PDB) and Packet Error Rate (PER). On the other hand, if non-standardized or dynamically assigned 5QI values ​​are used, signaling of the complete 5G QoS characteristics (including PDB and PER) is required as part of the QoS profile.

[0004] GFBR indicates the bit rate the network guarantees to provide to a GBR QoS flow over an averaging time window. PDB defines an upper bound on the amount of time a packet may be delayed between the User Equipment (UE) and the N6 termination point in the User Plane Function (UPF). The PDB applies to downlink packets received on the N6 interface by the UPF and uplink packets transmitted by the UE. PER defines an upper bound on the rate of Protocol Data Units (PDUs) (e.g., Internet Protocol (IP) packets) processed by the transmitter of a link layer protocol (e.g., Radio Link Control (RLC) in the RAN for 3GPP access) but not successfully delivered to the corresponding higher layer (e.g., Packet Data Convergence Protocol (PDCP) in the RAN for 3GPP access) at the receiver. PER therefore defines an upper bound on the non-congestion-related packet loss rate.

[0005] The QoS parameter notification control (hereinafter referred to as the notification control parameter) indicates whether to request notification from NG-RAN when GFBR can no longer (or can again) be guaranteed for a QoS flow during the QoS flow's lifetime. The notification control parameter can be used for GBR QoS flows when the application traffic can adapt to QoS changes (e.g., when the Application Function (AF) can trigger rate adaptation). The SMF enables the notification control only if the notification control parameter is set in the Policy and Charging Control (PCC) rule (received from the Policy Control Function (PCF)) associated with the QoS flow.

[0006] For a GBR QoS flow, if notification control is enabled and the NG-RAN determines that the GFBR, PDB, or PER of the QoS profile cannot be met, the NG-RAN sends a notification to the SMF stating that "GFBR can no longer be guaranteed." The NG-RAN can determine that "GFBR can no longer be guaranteed" based on measurements such as queuing delay and system load. Furthermore, unless a specific condition in the NG-RAN requires the release of NG-RAN resources for this GBR QoS flow due to, for example, a radio link failure or internal RAN congestion, the NG-RAN keeps the QoS flow even while it cannot meet the requested QoS profile for this QoS flow. The NG-RAN must then make an effort to meet the GFBR, PDB, and PER of the QoS profile again.

[0007] The SMF can receive QoS notification control information (i.e., events such as "GFBR can no longer be guaranteed" and "GFBR can be guaranteed again") from the NG-RAN via the AMF. Additionally or alternatively, based on the PCC rule, the SMF may instruct the NG-RAN to report the QoS notification control information via the tunnel between the NG-RAN and the PDU Session Anchor (PSA) UPF, and instruct the PSA UPF to notify when the report is received as instructed. In this case, the SMF can receive the QoS notification control information from the NG-RAN via the PSA UPF. When the SMF receives the notification that "GFBR can no longer be guaranteed" from the NG-RAN, it may forward the notification to the PCF. If the NG-RAN determines that the GFBR, PDB, and PER of the QoS profile for the QoS flow (for which the notification "GFBR can no longer be guaranteed" was sent) can be fulfilled again, the NG-RAN notifies the SMF that "GFBR can be guaranteed" again. The SMF may forward this notification to the PCF.

[0008] For a GBR QoS flow, if notification control is enabled and the NG-RAN has received a list of alternative QoS profiles for this QoS flow and supports handling of alternative QoS profiles, the following applies: If the NG-RAN determines that it cannot meet the GFBR, PDB, or PER of the QoS profile, it sends a notification to the SMF stating "GFBR can no longer be guaranteed." Before sending the notification "GFBR can no longer be guaranteed" to the SMF, the NG-RAN checks whether the GFBR, PDB, and PER currently met by the NG-RAN match any of the alternative QoS profiles, in the indicated priority order. If there is a match, the NG-RAN indicates the reference to the matching alternative QoS profile with the highest priority together with the notification to the SMF. If no match is found, the NG-RAN sends a notification to the SMF that "GFBR can no longer be guaranteed" and indicates that the lowest alternative QoS profile cannot be met (unless certain conditions in the NG-RAN require the release of NG-RAN resources for this GBR QoS flow, such as due to radio link failure or internal RAN congestion). The alternative QoS profile indicates a combination of QoS parameters: PDB, PER, Averaging Window, and GFBR to which the application traffic can adapt.

[0009] If the NG-RAN determines that the currently satisfied GFBR, PDB, or PER has changed (improved or worsened) from the situation indicated in the previous notification after the notification "GFBR can no longer be guaranteed" has been sent to the SMF, the NG-RAN sends a notification (i.e., "GFBR can no longer be guaranteed" or "GFBR can be guaranteed again") to the SMF and indicates the current situation (unless a specific condition in the NG-RAN requires the release of NG-RAN resources for this GBR QoS flow due to a radio link failure or internal RAN congestion, for example). The current situation is either that the QoS profile can be satisfied (which is implicit in the "GFBR can be guaranteed again" notification itself), that a different alternative QoS profile can be satisfied, or that the lowest priority alternative QoS profile cannot be satisfied. The NG-RAN always attempts to satisfy the QoS profile, and if that is not possible, it attempts to satisfy an alternative QoS profile with a higher priority. Upon receiving a notification from the NG-RAN, the SMF may inform the PCF. In that case, the SMF indicates the currently satisfied situation to the PCF. Unless otherwise instructed by the PCF, the SMF uses Non-Access Stratum (NAS) signaling (sent transparently through the RAN) to inform the UE about changes in the QoS parameters (e.g., 5QI, GFBR, MFBR) currently satisfied by the NG-RAN for the QoS flow after the notification control has occurred.

[0010] 3GPP TS 23.1106 / ...

[0011] The PDU SESSION RESOURCE NOTIFY message contains information of PDU session resources or QoS flows that are released or are no longer filled or are refilled by the NG-RAN node. Specifically, for each PDU session for which some QoS flows are released or are no longer filled or are refilled by the NG-RAN node, the PDU SESSION RESOURCE NOTIFY message contains a PDU Session Resource Notify Transfer information element (IE).

[0012] The PDU Session Resource Notify Transfer IE may include a QoS Flow Notify List IE. The QoS Flow Notify List IE indicates a list of GBR QoS flows that are no longer fulfilled or to be fulfilled again by the NG-RAN node. Specifically, the QoS Flow Notify List IE includes a QoS Flow Identifier IE and a Notification Cause IE for each QoS flow included in the list. The Notification Cause IE is of enumeration type and can indicate "fulfilled" or "not fulfilled." The NG-RAN node may indicate in the Current QoS Parameters Set Index IE an alternative QoS parameter set that can currently be fulfilled for a QoS flow that is indicated as no longer fulfilled.

[0013] Upon receiving the PDU SESSION RESOURCE NOTIFY message, the AMF transparently forwards, for each PDU session indicated in the PDU Session ID IE, a PDU Session Resource Notify Transfer IE to the SMF associated with that PDU session. Upon receiving the PDU Session Resource Notify Transfer IE, the SMF typically initiates appropriate release or modification procedures on the core network side for the PDU session(s) or QoS flow(s) identified as no longer being satisfied.

[0014] 3GPP TS 23.501 V18.1.0 (2023-03) "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; System architecture for the 5G System (5GS); Stage 2 (Release 18)", March 20233GPP TS 38.413 V17.4.0 (2023-03) "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NG-RAN; NG Application Protocol (NGAP) (Release 17)", March 2023

[0015] The notification control specified in 3GPP Release 15 and later releases may have some room for improvement, for example, in the following respects:

[0016] One of these improvements relates to notification from the NG-RAN to the core network (e.g., AMF, UPF, or SMF) of the reason (or cause, or factor) that led to a decision about QoS notification control information. As described above, for each GBR QoS flow, the NG-RAN can send a notification to the core network (e.g., AMF, UPF, or SMF) that the GFBR or QoS profile is no longer satisfied or is again satisfied. However, the current 3GPP specification's notification control provisions do not allow the NG-RAN to inform the core network of the reason why the NG-RAN determined that the GFBR or QoS profile is no longer satisfied. Note that, as already explained, a situation in which a specified QoS profile is no longer satisfied may be a situation in which any alternative QoS profile is satisfied. This may also be a situation in which even the lowest-priority alternative QoS profile cannot be satisfied. Similarly, the current 3GPP specification's QoS notification control provisions do not allow the NG-RAN to inform the core network of the reason why the NG-RAN determined that the specified GFBR or QoS profile is again satisfied. Notification from the NG-RAN to the core network of the reasons (or causes or factors) that led to the decision on the QoS notification control information may be useful for the core network (e.g., SMF or PCF or both) to optimize the actions taken with respect to the QoS flow.

[0017] Another of these improvements relates to the notification from the NG-RAN to the core network of the QoS parameters (e.g., GFBR, PDB, PER, 5QI) or QoS profile preferred by the NG-RAN. As described above, for each GBR QoS flow, the NG-RAN can send a notification to the core network (e.g., AMF, UPF, or SMF) that the GFBR or QoS profile is no longer satisfied or is again satisfied. Furthermore, if the NG-RAN has received a list of alternative QoS profiles for a GBR QoS flow and supports handling of alternative QoS profiles, the NG-RAN can send a reference to the highest-priority matching alternative QoS profile for this GBR QoS flow to the core network along with a notification that the specified QoS profile is no longer satisfied. However, the NG-RAN may prefer a different value of the QoS parameter for a GBR QoS flow than the value of the QoS parameter indicated by the QoS profile specified by the core network for that GBR QoS flow, or than the alternative value of that QoS parameter indicated by any alternative QoS profile. The current 3GPP specification for notification control does not allow the NG-RAN to notify the core network of one or more QoS parameters for a GBR QoS flow that are more preferred by the NG-RAN. Informing the core network of the QoS parameter values ​​more preferred by the NG-RAN for a certain QoS flow may be useful for the core network (e.g., SMF or PCF, or both) to optimize the actions it takes with respect to that QoS flow.

[0018] The above-described improvements to notification control defined in the 3GPP specifications may also be necessary or beneficial in communication systems other than 3GPP systems or fifth generation (5G) systems, such as Beyond 5G and sixth generation (6G) communication systems.

[0019] One of the objectives to be achieved by the embodiments disclosed in this specification is to provide an apparatus, a method, and a program that contribute to at least one of multiple improvements (including those described above) to notification control between a RAN and a core network. It should be noted that this objective is only one of multiple objectives to be achieved by the multiple embodiments disclosed in this specification. Other objectives or problems and novel features will become apparent from the description of this specification or the accompanying drawings.

[0020] In a first aspect, a Radio Access Network (RAN) node is configured to receive a QoS profile for a packet flow from a core network, and is further configured to, when sending a notification to the core network that the QoS profile is no longer met or that the QoS profile will be met again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow, also inform the core network of reasons, causes, or factors that led to the determination that the QoS profile is no longer met or that the QoS profile will be met again.

[0021] In a second aspect, a method performed by a RAN node includes the steps of: (a) receiving a QoS profile for a packet flow from a core network; and (b) sending a notification to the core network that the QoS profile is no longer met or that the QoS profile will be met again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow, also informing the core network of the reasons, causes, or factors that led to the determination that the QoS profile is no longer met or that the QoS profile will be met again.

[0022] In a third aspect, a core network node is configured to send a QoS profile for a packet flow to a RAN node, and further configured to receive from the RAN node a first notification that the packet flow is not released or the setup or modification of the packet flow is not rejected, and the packet flow is maintained but the QoS profile is no longer met or the QoS profile is again met, together with a second notification of reasons, causes, or factors that led to the determination that the QoS profile is no longer met or is again met.

[0023] In a fourth aspect, a method performed by a core network node includes the steps of: (a) sending a QoS profile for a packet flow to a RAN node; and (b) receiving a first notification from the RAN node that the packet flow is not released or the setup or modification of the packet flow is not rejected and the packet flow is maintained but the QoS profile is no longer met or the QoS profile is again met, along with a second notification of reasons, causes, or factors that led to the determination that the QoS profile is no longer met or is again met.

[0024] In a fifth aspect, a RAN node is configured to receive a QoS profile for a packet flow from a core network, and further configured to, when sending a notification to the core network that the QoS profile is no longer satisfied or that the QoS profile is again satisfied while maintaining the packet flow, also inform the core network of values ​​preferred by the RAN node of one or more QoS parameters for the packet flow.

[0025] In a sixth aspect, a method performed by a RAN node includes the steps of: (a) receiving a QoS profile for a packet flow from a core network; and (b) informing the core network that the QoS profile is no longer satisfied or that the QoS profile will be satisfied again while maintaining the packet flow, also informing the core network of values ​​preferred by the RAN node of one or more QoS parameters for the packet flow.

[0026] In a seventh aspect, a core network node is configured to send a QoS profile for a packet flow to a RAN node, and further configured to receive a first notification from the RAN node that the packet flow is maintained but that the QoS profile is no longer satisfied or that the QoS profile is again satisfied, together with a second notification indicating preferred values ​​for the RAN node of one or more QoS parameters for the packet flow.

[0027] In an eighth aspect, a method performed by a core network node includes the steps of: (a) sending a QoS profile for a packet flow to a RAN node; and (b) receiving a first notification from the RAN node that the packet flow is maintained but the QoS profile is no longer satisfied or that the QoS profile is again satisfied, together with a second notification indicating preferred values ​​for the RAN node of one or more QoS parameters for the packet flow.

[0028] In a ninth aspect, a program includes a set of instructions (software code) that, when loaded into a computer, causes the computer to perform the operations or methods of the RAN node or core network node described in the above aspects.

[0029] According to the above-described aspects, it is possible to provide an apparatus, a method, and a program that contribute to at least one of a number of improvements (including those described above) to notification control between the RAN and the core network.

[0030] 1 illustrates an example configuration of a wireless communication system according to one or more embodiments. 2 illustrates a flowchart illustrating an example operation of a RAN node according to one or more embodiments. 3 illustrates a flowchart illustrating an example operation of a core network node according to one or more embodiments. 4 illustrates an example signaling between a RAN node and a core network node according to one or more embodiments. 5 illustrates an example signaling between a RAN node and a core network node according to one or more embodiments. 6 illustrates an example format of a PDU Session Resource Notify Transfer information element according to one or more embodiments. 7 illustrates an example format of a PDU Session Resource Notify Transfer information element according to one or more embodiments. 8 illustrates an example format of a PDU Session Resource Modify Response Transfer information element according to one or more embodiments. 9 illustrates an example format of a PDU Session Resource Setup Response Transfer information element according to one or more embodiments. 10 illustrates an example flowchart illustrating an example operation of a RAN node according to one or more embodiments. 11 illustrates an example flowchart illustrating an example operation of a core network node according to one or more embodiments. 12 illustrates an example signaling between a RAN node and a core network node according to one or more embodiments. Figure 1 illustrates an example of signaling between a RAN node and a core network node, which is relevant to one or more embodiments;Figure 2 illustrates an example of signaling between a RAN node and a core network node, which is relevant to one or more embodiments;Figure 3 illustrates an example of a format of a PDU Session Resource Notify Transfer information element, which is relevant to one or more embodiments.Figure 1 illustrates an example format of a PDU Session Resource Modify Response Transfer information element in accordance with one or more embodiments; Figure 2 illustrates an example format of a PDU Session Resource Setup Response Transfer information element in accordance with one or more embodiments; Figure 3 illustrates an example configuration of a RAN node in accordance with one or more embodiments; Figure 4 illustrates an example configuration of a core network node in accordance with one or more embodiments;

[0031] Hereinafter, specific embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are designated by the same reference numerals, and for clarity of explanation, duplicate explanations will be omitted as necessary.

[0032] The multiple embodiments described below may be used independently, or two or more embodiments may be combined as appropriate. These multiple embodiments may have different novel features. Therefore, these multiple embodiments may contribute to achieving different objectives or solving different problems, and may contribute to achieving different effects.

[0033] Each drawing is merely an example for describing one or more embodiments. Each drawing may not relate to only one particular embodiment, but may also relate to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0034] The following embodiments are described primarily for 3GPP 5G systems, but may also be applied to other communication systems that support notification control and similar techniques defined in the 3GPP specifications.

[0035] As used herein, depending on the context, "if" may be interpreted to mean "when," "while," "at or around the time," "after," "upon," "in response to determining," "in accordance with a determination," or "in response to detecting." These expressions may be interpreted to have the same meaning, depending on the context.

[0036] First, the configuration and operation of multiple network elements common to multiple embodiments will be described. Figure 1 shows an example configuration of a wireless communication system related to multiple embodiments. Each element (network function) shown in Figure 1 can be implemented, for example, as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on an application platform.

[0037] The wireless communication system shown in Fig. 1 may be provided by a Mobile Network Operator (MNO) or a Non-Public Network (NPN) provided by a party other than an MNO. If the cellular network shown in Fig. 1 is an NPN, it may be an independent network called a Stand-alone Non-Public Network (SNPN), or an NPN that works in conjunction with an MNO network called a Public network integrated NPN (PNI-NPN).

[0038] In the example of FIG. 1, the wireless communication system includes a UE 1, an NG-RAN 2, and a 5G Core Network (5GC) 4. UE 1 may be referred to by other terms, such as a wireless terminal, a mobile terminal, a mobile station, or a wireless transmit receive unit (WTRU). NG-RAN 2 includes one or more NG-RAN nodes 3. 5GC 4 includes one or more network functions or nodes in the control plane and one or more functions or nodes in the user plane. FIG. 1 illustrates some representative network functions or nodes in 5GC 4, including an AMF 5, an SMF 6, a PCF 7, and a UPF 8. The UPF 8 may include multiple interconnected UPFs. UE 1 utilizes 5G connectivity services provided by the NG-RAN 2 and the 5GC 4 to communicate with a Data Network (DN) 9. More specifically, UE 1 is connected to the NG-RAN node 3 in the NG-RAN 2 and communicates with the DN 9 via the UPF 8 in the 5GC 4.

[0039] UE1 establishes one or more Protocol Data Unit (PDU) sessions 100 between UE1 and a UPF8 (i.e., a PDU session anchor (PSA)) to which DN9 is connected. The PDU session 100 is an association, session, or connection between UE1 and DN9. The PDU session 100 is used to provide PDU connectivity services (i.e., the exchange of PDUs between UE1 and DN9). From a data transfer perspective, the PDU session 100 consists of a tunnel within 5GC4 (N9 tunnel), a tunnel between 5GC4 and NG-RAN2 (N3 tunnel), and one or more radio bearers. Although not shown in FIG. 1 , UE1 may establish multiple PDU sessions with multiple UPFs (PDU session anchors) 8 to access multiple DNs9 concurrently.

[0040] The 5G QoS model is based on QoS flows. It supports both QoS flows that require flow bit rate guarantees (GBR QoS flows) and QoS flows that do not require flow bit rate guarantees (Non-GBR QoS flows). QoS flows are the finest granularity of QoS differentiation within a PDU session. In other words, QoS flows are the finest granularity for QoS forwarding treatment in a 5G system. All traffic mapped to the same 5G QoS flow receives the same forwarding treatment (e.g., scheduling policy, queue management policy, rate shaping, Radio Link Control (RLC) settings, etc.). To provide different QoS forwarding treatments, separate QoS flows are required.

[0041] Every QoS flow is characterized by a QoS profile; one or more QoS rules and optional QoS flow level parameters; and one or more uplink and downlink Packet Detection Rule(s) (PDR(s)). The QoS profile is provided from the SMF 6 to the NG-RAN 2 (or NG-RAN node 3) via the AMF 5 over the N2 reference point. One or more QoS rules and QoS flow level parameters are provided from the SMF 6 to the UE 1 via the AMF 5 over the N1 reference point. One or more uplink and downlink PDR(s) are provided from the SMF 6 to the UPF 8.

[0042] 1, multiple QoS flows 120 associated with different QoS requirements can be established for one PDU session 100. One or more applications 10 in UE1 transmit or receive multiple packet flows to or from one or more applications 90 in DN9 via multiple QoS flows 120. As can be understood from the above description, a QoS flow can be considered as a packet flow between UE1 and 5GC4, consisting of one or more packet flows transferred between UE1 and DN9. Alternatively, a QoS flow can be considered as a transmission path or connection set up or established between UE1 and 5GC4 for forwarding one or more packet flows transferred between UE1 and DN9.

[0043] The NG-RAN node 3 provides one or more cells, and the UE 1 may be simultaneously connected to multiple cells provided by the NG-RAN node 3. In other words, the UE 1 may perform carrier aggregation (CA) between multiple cells provided by the NG-RAN node 3. In addition, the UE 1 may be simultaneously connected to the NG-RAN node 3 and another RAN node (e.g., an NG-RAN node or an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) node) for dual connectivity (DC). This dual connectivity may be Multi-Radio Dual Connectivity (MR-DC).

[0044] The NG-RAN node 3 may be a gNB or an ng-eNB, which is a node that provides Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol termination to the UE and is connected to the 5GC via an NG interface.

[0045] The NG-RAN node 3 may be a Central Unit (e.g., gNB-CU) in a cloud RAN (C-RAN) deployment, or a combination of a CU and one or more Distributed Units (e.g., gNB-DUs). C-RAN is also referred to as a CU / DU split. Furthermore, a CU may include a Control Plane (CP) Unit (e.g., gNB-CU-CP) and one or more User Plane (UP) Units (e.g., gNB-CU-UP). Thus, the NG-RAN node 3 may be a CU-CP or a combination of a CU-CP and a CU-UP. The CU may be a logical node that hosts the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols of the gNB (or the RRC and PDCP protocols of the gNB). The DU may be a logical node that hosts the Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers of the gNB.

[0046] The AMF 5 is one of the network functions within the 5GC control plane. The AMF 5 provides the termination of the RAN Control Plane (CP) interface (i.e., N2 interface). The AMF 5 terminates a single signaling connection (i.e., NAS signaling connection) with the UE 1 and provides registration management, connection management, and mobility management. Registration management is used to register or deregister the UE 1 to the network (5G system). Connection management is used to establish and release the NAS signaling connection between the UE 1 and the AMF 5. Mobility management is used to keep track of the location of the UE 1. Mobility management uses a periodic registration update procedure and a mobility registration update procedure. Therefore, in the 5G system, mobility management can also be said to be included in registration management.

[0047] The AMF 5 provides NF services to Network Function (NF) consumers (e.g., other AMFs and the SMF 6) over a service-based interface (i.e., the Namf interface). The NF services provided by the AMF 5 include a communication service (Namf_Communication). The communication service enables the NF consumers (e.g., the SMF 6) to communicate with the UE 1 or the NG-RAN 2 via the AMF 5.

[0048] The SMF 6 is one of the network functions in the 5GC control plane. The SMF 6 provides session management. The session management is used to establish, modify, and release PDU sessions to provide PDU connectivity services to the UE 1. The session management includes signaling between the UE 1, the NG-RAN 2, the AMF 5, and the UPF 8 for establishing, modifying, and releasing PDU sessions.

[0049] The SMF 6 transmits and receives SM signaling messages (NAS-SM messages, N1 SM messages) to and from the NAS Session Management (SM) layer of the UE 1 via the communication service provided by the AMF 5. In addition, the SMF 6 transmits and receives N2SM information to and from the NG-RAN 2 (or NG-RAN node 3) via the communication service provided by the AMF 5. The N2SM information sent from the SMF 6 to the NG-RAN 2 via the AMF 5 can include, among other information, a PDU session ID, QoS flow identifiers (QFIs) and QoS profiles of one or more QoS flows. The N2SM information sent from the NG-RAN 2 to the SMF 6 via the AMF 5 can also include, among other information, the QFI of a QoS flow and QoS notification control information for the QoS flow. The QoS notification control information indicates whether the QoS profile or target (e.g., GFBR) of the QoS flow cannot be fulfilled or can be fulfilled again.

[0050] The SMF 6 provides NF services to NF consumers (e.g., AMF 5 and other SMFs) over a service-based interface (i.e., the Nsmf interface). The NF services provided by the SMF 6 include a session management service (Nsmf_PDUSession), which allows NF consumers (e.g., AMF 5) to handle PDU sessions.

[0051] The PCF7 is one of the network functions in the 5GC control plane. The PCF7 supports interactions with access and mobility policy enforcement in the AMF5 via a service-based interface. The PCF7 provides access and mobility management related policies to the AMF5. In addition, the PCF7 provides session-related policies to the SMF6. The session-related policies include PDU session-related policy information and PCC rule information.

[0052] NG-RAN2 and 5GC4 support notification control, also known as QoS Notification Control (QNC). QoS notification control enables 5GC4 to receive notifications from NG-RAN2 when the Guaranteed Flow Bit Rate (GFBR) can no longer (or can again) be guaranteed for GBR QoS flows.

[0053] As described above, the QoS profile of a QoS flow can be provided to the NG-RAN 2 (or NG-RAN node 3) by the SMF 6 in the 5G QoS Controller 4 via the AMF 5. A QoS flow can be either "GBR" or "non-GBR" depending on its QoS profile. The QoS profile includes multiple QoS parameters. For each QoS flow, the QoS profile includes 5QI and ARP. Additionally, for each GBR QoS flow, the QoS profile includes GFBR and MFBR. Furthermore, for each GBR QoS flow, the QoS profile may include notification control. Note that when a standardized 5QI value is used, the 5QI value defines static values ​​for PDB and PER. On the other hand, when a non-standardized or dynamically assigned 5QI value is used, signaling of the complete 5G QoS characteristics (including PDB and PER) is required as part of the QoS profile.

[0054] GFBR indicates the bit rate the network guarantees to provide to a GBR QoS flow over an averaging time window. PDB defines an upper bound on the time a packet may be delayed between UE1 and the N6 termination point of UPF8. PDB applies to downlink packets received on the N6 interface by UPF8 and uplink packets transmitted by UE1. PER defines an upper bound on the rate of PDUs (e.g., IP packets) processed at the transmitting side of a link layer protocol (e.g., RLC in 3GPP access) but not successfully delivered to the corresponding upper layer at the receiving side (e.g., PDCP in RAN in 3GPP access). Thus, PER defines an upper bound on the non-congestion-related packet loss rate.

[0055] The QoS parameter notification control (or notification control parameter) indicates whether to request notification from NG-RAN 2 when GFBR can no longer (or can again) be guaranteed for a QoS flow during the lifetime of the QoS flow. The notification control parameter can be used for GBR QoS flows when the application traffic can adapt to QoS changes (e.g., when the Application Function (AF) can trigger rate adaptation). The SMF 6 enables notification control only if the notification control parameter is set in the PCC rule (received from the PCF 7) associated with the QoS flow.

[0056] For a GBR QoS flow, if notification control is enabled and the NG-RAN node 3 determines that the GFBR, PDB, or PER of the QoS profile cannot be met, the NG-RAN node 3 sends a notification to the SMF 6 stating that "GFBR can no longer be guaranteed." The NG-RAN node 3 can determine that "GFBR can no longer be guaranteed" based on measurements such as queuing delay and system load. Furthermore, unless a specific condition in the NG-RAN node 3 requires the release of NG-RAN resources for this GBR QoS flow due to, for example, a radio link failure or internal RAN congestion, the NG-RAN node 3 keeps the QoS flow even while it does not meet the QoS profile requested for this QoS flow. The NG-RAN node 3 then makes an effort to meet the GFBR, PDB, and PER of the QoS profile again.

[0057] The SMF 6 can receive QoS notification control information (i.e., events such as "GFBR can no longer be guaranteed" and "GFBR can be guaranteed again") from the NG-RAN node 3 via the AMF 5. Additionally or alternatively, based on the PCC rule, the SMF 6 may instruct the NG-RAN node 3 to report the QoS notification control information via the tunnel between the NG-RAN node 3 and the PSA UPF 8, and instruct the PSA UPF 8 to notify when the report is received as instructed. In this case, the SMF 6 can receive the QoS notification control information from the NG-RAN node 3 via the PSA UPF 8. Upon receiving the notification that "GFBR can no longer be guaranteed" from the NG-RAN node 3, the SMF 6 may forward the notification to the PCF 7. If the NG-RAN node 3 determines that the GFBR, PDB, and PER of the QoS profile for the QoS flow (for which the notification that "GFBR can no longer be guaranteed" was sent) can be fulfilled again, the NG-RAN node 3 notifies the SMF 6 that "GFBR can be guaranteed" again. The SMF 6 may forward this notification to the PCF 7.

[0058] For a GBR QoS flow, if notification control is enabled and the NG-RAN node 3 has received a list of alternative QoS profiles for this QoS flow and supports handling of alternative QoS profiles, the following applies: If the NG-RAN node 3 determines that it cannot meet the GFBR, PDB, or PER of the QoS profile, it shall send a notification to the SMF 6 stating that "GFBR can no longer be guaranteed". Before sending the notification that "GFBR can no longer be guaranteed" to the SMF 6, the NG-RAN node 3 shall check whether the GFBR, PDB, and PER currently met by the NG-RAN node 3 match any of the alternative QoS profiles, in the order of the indicated priority. If there is a match, the NG-RAN node 3 shall indicate, together with the notification to the SMF 6, the reference to the matching alternative QoS profile with the highest priority. If no match is found, the NG-RAN node 3 sends a notification to the SMF 6 that "GFBR can no longer be guaranteed" and indicates that the lowest alternative QoS profile cannot be met (unless specific conditions in the NG-RAN node 3 require the release of NG-RAN resources for this GBR QoS flow, such as due to radio link failure or internal RAN congestion). The alternative QoS profile indicates a combination of QoS parameters: PDB, PER, Averaging Window, and GFBR to which the application traffic can adapt.

[0059] If the NG-RAN node 3 has already sent a notification that "GFBR can no longer be guaranteed" to the SMF 6 and determines that the currently satisfied GFBR, PDB, or PER is different (better or worse) from the situation indicated in the previous notification, the NG-RAN node 3 sends a notification (i.e., "GFBR can no longer be guaranteed" or "GFBR can be guaranteed again") to the SMF 6 and indicates the current situation (unless a specific condition in the NG-RAN node 3 requires the release of NG-RAN resources for this GBR QoS flow due to a radio link failure or internal RAN congestion, for example). The current situation is either that the QoS profile can be satisfied (which is implicit in the "GFBR can again be guaranteed" notification itself), that a different alternative QoS profile can be satisfied, or that the lowest priority alternative QoS profile cannot be satisfied. The NG-RAN node 3 always attempts to satisfy the QoS profile, and if that is not possible, it attempts to satisfy an alternative QoS profile with a higher priority. Upon receiving a notification from the NG-RAN node 3, the SMF 6 may inform the PCF 7. In that case, the SMF 6 indicates the currently satisfied status to the PCF 7. Unless otherwise instructed by the PCF 7, the SMF 6 uses NAS signaling to inform the UE 1 about changes in the QoS parameters (5QI, GFBR, MFBR, etc.) currently satisfied by the NG-RAN 2 for the QoS flow after the notification control has occurred.

[0060] The NG-RAN node 3 and the AMF 5 support the PDU Session Resource Notify procedure. One of the purposes of the PDU Session Resource Notify procedure is to notify that already established QoS flow(s) or PDU session(s) for the UE 1 are released, or are not fulfilled anymore, or are fulfilled again, by the NG-RAN node 3 for which notification control is required. This procedure uses UE-associated or UE-specific signaling. The NG-RAN node 3 initiates the procedure by sending a PDU SESSION RESOURCE NOTIFY message.

[0061] The PDU SESSION RESOURCE NOTIFY message contains information of PDU session resources or QoS flows that are released or are no longer filled or are refilled by the NG-RAN node 3. Specifically, for each PDU session for which some QoS flows are released or are no longer filled or are refilled by the NG-RAN node 3, the PDU SESSION RESOURCE NOTIFY message contains a PDU Session Resource Notify Transfer information element (IE).

[0062] The PDU Session Resource Notify Transfer IE may include a QoS Flow Notify List IE. The QoS Flow Notify List IE indicates a list of GBR QoS flows that are no longer fulfilled or to be fulfilled again by the NG-RAN node 3. Specifically, the QoS Flow Notify List IE includes a QoS Flow Identifier IE and a Notification Cause IE for each QoS flow included in the list. The Notification Cause IE is of enumeration type and may indicate "fulfilled" or "not fulfilled." The NG-RAN node 3 may indicate in the Current QoS Parameters Set Index IE an alternative QoS parameter set that can currently be fulfilled for a QoS flow that is indicated as no longer fulfilled.

[0063] Upon receiving the PDU SESSION RESOURCE NOTIFY message, the AMF 5 transparently forwards, for each PDU session indicated in the PDU Session ID IE, a PDU Session Resource Notify Transfer IE to the SMF 6 associated with that PDU session. Upon receiving the PDU Session Resource Notify Transfer IE, the SMF 6 may initiate appropriate release or modification procedures on the 5GC 4 side for the PDU session(s) or QoS flow(s) identified as no longer being satisfied.

[0064] First Embodiment A configuration example of a wireless communication system according to this embodiment is similar to the configuration example described with reference to Fig. 1. This embodiment provides an improvement in QoS notification control.

[0065] Figure 2 shows an example of the operation of a RAN node. The RAN node may be the NG-RAN node 3 shown in Figure 1. In step 201, the RAN node receives a QoS profile for a packet flow from a core network. The core network may be the 5GC 4 shown in Figure 1. The packet flow may be a QoS flow in a PDU session. The RAN node may receive the QoS profile for the packet flow in an initial context setup procedure, a PDU session resource setup procedure, or a PDU session resource modification procedure. The QoS profile may include QoS parameters including 5QI, ARP, and GBFR. The QoS profile may include a notification control parameter. The notification control parameter may indicate that notification control is enabled for the QoS flow.

[0066] In step 202, when sending a notification to the core network that the QoS profile is no longer met or will be met again while maintaining the packet flow, the RAN node also informs the core network of the reason, cause, or factor(s) that led to that decision. More specifically, when sending a notification to the core network that the QoS profile is no longer met or will be met again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow, the RAN node also informs the core network of the reason, cause, or factor(s) that led to that decision.

[0067] As already explained, if the RAN node has received a list of alternative QoS profiles in addition to the QoS profile for the packet flow, a situation in which a QoS profile is no longer satisfied may be a situation in which any of the alternative QoS profiles are satisfied, or it may be a situation in which even the lowest priority alternative QoS profile cannot be satisfied.

[0068] The reason, cause, or factor notified by the RAN node in step 202 may include a reason, cause, or factor that is due to measurements of queuing delay or system load. In other words, the notification of step 202 may include an indication that the determination that the QoS profile is no longer being met or will again be met is based on, results from, or relates to measurements of queuing delay or system load.

[0069] Additionally or alternatively, the reason, cause, or factor notified by the RAN node in step 202 may indicate the location or element within the RAN that led to or triggered the transmission of the QoS notification control information. In some implementations, the notification in step 202 may indicate whether the determination that the QoS profile is no longer met or will be met again is due to a problem with the CU, DU, or radio link quality (or Radio Unit (RU)). For example, the notification in step 202 may indicate that the determination that the QoS profile of a packet flow is no longer met is due to CU overload, DU overload, or radio link quality degradation. In other implementations, the notification in step 202 may indicate whether the determination that the QoS profile is no longer met or will be met again is due to a problem with the PDCP layer, RLC layer, MAC layer, or PHY layer. For example, the notification in step 202 may indicate that the determination that the QoS profile of a packet flow is no longer met is due to congestion or overload of the PDCP entity or buffer for the radio bearer associated with the packet flow. Alternatively, the notification of step 202 may indicate that the reason for the determination is congestion or overload of an RLC entity or buffer, or that the reason for the determination is a scheduling delay in a MAC entity.

[0070] Additionally or alternatively, the reason, cause, or factor notified by the RAN node in step 202 may include a reason, cause, or factor due to a request for radio bandwidth by another higher priority GBR QoS flow. In other words, the notification of step 202 may include an indication that the determination that the QoS profile is no longer satisfied is based on, caused by, or related to a request for radio bandwidth by another higher priority GBR QoS flow. The notification of step 202 may also include an indication that the determination that the QoS profile is again satisfied is based on, caused by, or related to the elimination of a request for radio bandwidth by another higher priority GBR QoS flow (or the release of another higher priority GBR QoS flow).

[0071] Additionally or alternatively, the reason, cause, or factor notified by the RAN node in step 202 may include a reason, cause, or factor that is based on the result of an Artificial Intelligence (AI) or Machine Learning (ML) inference. The reason, cause, or factor notified by the RAN node in step 202 may include information indicative of the reason, cause, or factor that is based on the result of an inference using AI or ML. In other words, the notification in step 202 may include an indication that the determination that the QoS profile is no longer met or will again be met is based on, results from, or relates to the result of an inference using a trained AI or ML model.

[0072] Additionally or alternatively, the reason, cause, or factor notified by the RAN node in step 202 may include a reason, cause, or factor due to a radio link failure or radio access network internal congestion. In other words, the notification of step 202 may include an indication that the determination that the QoS profile is no longer met or will again be met is based on, caused by, or related to a radio link failure or radio access network internal congestion.

[0073] The RAN node may itself determine or generate a notification or indication of the reason, cause, or factor that led to the decision. Alternatively, the RAN node may determine the notification or indication of the reason, cause, or factor that led to the decision based on information received from another control node. Alternatively, the RAN node may receive the notification or indication of the reason, cause, or factor that led to the decision from another control node. The other control node may determine, through inference using a trained AI or ML model, that the QoS profile for a packet flow is not met or will be met again and notify the RAN node along with the reason that led to the decision. The other control node may be a Near-Real-Time (RT) RAN Intelligent Controller (RIC) or a Non-RT RIC. The technical specifications for Near-RT RIC and Non-RT RIC are provided by the Open Radio Access Network (O-RAN) Alliance.

[0074] The Near-RT RIC is a logical function that enables near-real-time control and optimization of RAN elements and resources through granular data collection and action over the E2 interface. The Near-RT RIC hosts a set of applications called xApps and provides a set of commonly used platform functions to support the specific functions hosted by the xApps. xApps are applications designed to run within the Near-RT RIC. xApps execute in the Near-RT RIC as part of the RAN (O-RAN). xApps are independent of the Near-RT RIC and can be provided by third parties. xApps are used to provide radio resource management over a standardized E2 interface and E2 service model. For example, xApps receive data from the RAN, calculate control actions as needed, and send them back.

[0075] The Non-RT RIC is a logical function within the Service Management and Orchestration (SMO) framework. The Non-RT RIC consists of the Non-RT RIC framework and Non-RT RIC applications (rApps). rApps are applications designed to run within the Non-RT RIC. rApps execute within the Non-RT RIC as part of the SMO framework. rApps leverage the functionality exposed by the Non-RT RIC to provide value-added services to support and facilitate RAN optimization and operations, such as policy guidance, enrichment information, configuration management, and data analytics.

[0076] The RAN node may send the notification of step 202 using a PDU Session Resource Notify procedure. Specifically, the RAN node may use a PDU SESSION RESOURCE NOTIFY message for the notification of step 202, including an indication of the reason, cause, or factor that led to the decision. Alternatively, the RAN node may send the notification of step 202 in an initial context setup procedure, a PDU session resource setup procedure, or a PDU session resource modification procedure. In this case, the RAN node may use an INITIAL CONTEXT SETUP RESPONSE, a PDU SESSION RESOURCE SETUP RESPONSE, or a PDU SESSION RESOURCE MODIFY RESPONSE message for the notification of step 202, including an indication of the reason, cause, or factor that led to the decision.

[0077] Figure 3 illustrates an example of the operation of a core network node in relation to the operation of the RAN node illustrated in Figure 2. The core network node may be the AMF 5 or SMF 6 illustrated in Figure 1. In step 301, the core network node sends a QoS profile for a packet flow (e.g., a QoS flow) to the RAN node. The RAN node may be the NG-RAN node 3 illustrated in Figure 1. The core network node (e.g., the SMF 6) may send the QoS profile to the RAN node via another core network node (e.g., the AMF 5). The core network node may send the QoS profile for the packet flow in an initial context setup procedure, a PDU session resource setup procedure, or a PDU session resource modification procedure. The QoS profile may include QoS parameters including 5QI, ARP, and GBFR. The QoS profile includes a notification control parameter, which may indicate that notification control is enabled for the QoS flow.

[0078] In step 302, the core network node receives from the RAN node a first notification that the packet flow is maintained but the QoS profile is no longer met or is again met, together with a second notification of the reasons, causes, or factors that led to the determination that the QoS profile is no longer met or is again met. More specifically, the core network node receives from the RAN node a first notification that the packet flow is maintained but the QoS profile is no longer met or is again met, without releasing or rejecting the setup or modification of the packet flow, together with the second notification of the reasons, causes, or factors that led to the determination that the QoS profile is no longer met or is again met. The core network node (e.g., SMF 6) may receive the first and second notifications from the RAN node via another core network node (e.g., AMF 5 or UPF 8).

[0079] As already explained, if the RAN node has received a list of alternative QoS profiles in addition to the QoS profile for the packet flow, a situation in which a QoS profile is no longer satisfied may be a situation in which any of the alternative QoS profiles are satisfied, or it may be a situation in which even the lowest priority alternative QoS profile cannot be satisfied.

[0080] Examples of reasons, causes or factors received by the core network node in step 302 are similar to those described above with respect to step 202. The message or information field containing or indicating the first and second notifications of step 302 may be sent in a notification control procedure (e.g., a PDU Session Resource Notify procedure), an Initial Context Setup procedure, a PDU Session Resource Setup procedure or a PDU Session Resource Modification procedure.

[0081] Figure 4 shows an example of signaling between a RAN node 410 and a core network node 420. The RAN node 410 may be the NG-RAN node 3 shown in Figure 1. The core network node 420 may be the AMF 5, SMF 6, or UPF 8 shown in Figure 1. In step 401, the RAN node 410 sends a control message or information field to the core network node 420. The control message or information field indicates that the QoS profile of a given (GBR) packet flow is not met or will be met again, along with the reason, cause, or factor(s) that led to the decision. The RAN node 410 (e.g., NG-RAN node 3) may send the control message or information field to the core network node 520 (e.g., SMF 6) via another core network node (e.g., AMF 5 or UPF 8). Examples of reasons, causes, or factors that the RAN node 410 notifies in step 401 are similar to those described above with respect to step 202.

[0082] The control message or information field of step 401 may be sent in a notification control procedure (e.g., PDU Session Resource Notify procedure). In particular, when sending a control message or information field indicating that the QoS profile of a packet flow (e.g., QoS flow) is not met or will be met again during the lifetime of the packet flow, i.e., while the packet flow is established and maintained, the RAN node 410 may include in the control message or information field an indication of the reason, cause, or factor that led to or triggered this notification.

[0083] Alternatively, the control message or information field of step 401 may be sent during a procedure involving the establishment or setup of a new packet flow. These procedures include, for example, an initial context setup procedure, a PDU session resource setup procedure, and a PDU session resource modification procedure. Specifically, when sending a response message indicating acceptance of the establishment or setup of a new packet flow, the RAN node 410 may include in the response message a notification indicating that the QoS profile of the packet flow is not met but that an alternative QoS profile is met. Additionally, the RAN node 410 may include in the control message or information field an indication of the reason, cause, or factor that led to or triggered this notification.

[0084] Alternatively, the control message or information field of step 401 may be sent in procedures involving modification of an established packet flow (e.g., modification of a QoS profile). These procedures include, for example, PDU session modification procedures. Specifically, when sending a response message indicating acceptance of the packet flow modification, the RAN node 410 may include in the response message a notification indicating that the QoS profile of the packet flow is not satisfied, but that an alternative QoS profile is satisfied. Additionally, the RAN node 410 may include in the control message or information field an indication of the reason, cause, or factor that led to or triggered this notification.

[0085] Figure 5 shows an example of signaling between a RAN node 510 and a core network node 520. The RAN node 510 may be the NG-RAN node 3 shown in Figure 1. The core network node 520 may be the AMF 5 shown in Figure 1. The signaling in Figure 5 is one example of the signaling in Figure 4. In step 501, the RAN node 510 sends a PDU SESSION RESOURCE NOTIFY message to the core network node 520. The PDU SESSION RESOURCE NOTIFY message indicates that the QoS profile of a (GBR) QoS flow is not satisfied or will be satisfied again, along with the reason, cause, or factor(s) that led to the decision. Examples of the reason, cause, or factor(s) that the RAN node 510 notifies in step 501 are the same as those described above with respect to step 202. The core network node 520 (eg, AMF 5) may forward these notifications or indications received from the RAN node 510 to other core network nodes (eg, SMF 6 or PCF 7).

[0086] Figure 6 shows an example of signaling between a RAN node 610 and a core network node 620. The RAN node 610 may be the NG-RAN node 3 shown in Figure 1. The core network node 620 may be the AMF 5 shown in Figure 1. The signaling in Figure 6 is one example of the signaling in Figure 4. In step 601, the RAN node 610 sends an INITIAL CONTEXT SETUP RESPONSE, a PDU SESSION RESOURCE SETUP RESPONSE, or a PDU SESSION RESOURCE MODIFY RESPONSE message to the core network node 620. The message indicates that the QoS profile of a certain (GBR) QoS flow is not satisfied, along with the reason, cause, or factor(s) that led to this determination. Examples of the reason, cause, or factor(s) that the RAN node 610 notifies in step 601 are the same as those described above with respect to step 202. The core network node 620 (eg, AMF 5) may forward these notifications or indications received from the RAN node 610 to other core network nodes (eg, SMF 6 or PCF 7).

[0087] Figure 7 shows an example of the format of an improved PDU Session Resource Notify Transfer information element (IE). The PDU Session Resource Notify Transfer IE is included in a PDU SESSION RESOURCE NOTIFY message sent from an NG-RAN node to an AMF. The PDU Session Resource Notify Transfer IE may include a QoS Flow Notify List IE. The QoS Flow Notify List IE indicates a list of GBR QoS flows that are no longer fulfilled or to be fulfilled again by the NG-RAN node. The QoS Flow Notify List IE includes a QoS Flow Identifier IE and a Notification Cause IE for each QoS flow included in the list. The Notification Cause IE is of enumerable type and can indicate "fulfilled" or "not fulfilled." Additionally, in the example of Figure 7, the Notification Cause IE is extended to indicate the reason, cause, or factor that led to the decision that the QoS profile of the GBR QoS flow is not fulfilled or to be fulfilled again. The NG-RAN node 3 may set the Notification Cause IE shown in Figure 7 to a value indicating the reason, cause or factor that led to the decision that the QoS profile of the GBR QoS flow is not met or will be met again.

[0088] For example, the Notification Cause IE in Fig. 7 may indicate "not fulfilled due to radio link failure", "not fulfilled due to RAN internal congestion", "fulfilled due to radio link recovery", "fulfilled due to RAN internal congestion resolution", or "fulfilled due to mobility". Additionally or alternatively, the Notification Cause IE may indicate "not fulfilled due to AI / ML result" or "fulfilled due to AI / ML result". Additionally or alternatively, the Notification Cause IE may indicate "not fulfilled due to bandwidth requested by other higher priority GBR QoS Flows" or "fulfilled due to absence of bandwidth requests by other high priority GBR QoS flows".

[0089] Figure 8 shows another example of the format of the improved PDU Session Resource Notify Transfer IE. In the example of Figure 8, the QoS Flow Notify List IE in the PDU Session Resource Notify Transfer IE is extended to include a Cause IE for each QoS flow included in the list. This Cause IE is used to indicate the reason, cause, or factor that led to the determination that the QoS profile of the GBR QoS flow is not met or is again met. Therefore, in this example, the set of values ​​that the Cause IE can indicate as the radio network layer cause is extended compared to the existing set. The NG-RAN node 3 may set the Cause IE shown in Figure 8 to a value that indicates the reason, cause, or factor that led to the determination that the QoS profile of the GBR QoS flow is not met or is again met.

[0090] For example, the Cause IE in FIG. 8 may indicate "radio link failure," "RAN internal congestion," "radio link recovery," or "RAN internal congestion resolution." Additionally or alternatively, the Cause IE may indicate "AI / ML result." Additionally or alternatively, the Cause IE may indicate "bandwidth requested by other higher priority GBR QoS Flows," or "absence of bandwidth requests by other high priority GBR QoS flows."

[0091] Figure 9 shows an example of the format of the improved PDU Session Resource Modify Response Transfer IE. The PDU Session Resource Modify Response Transfer IE is included in a PDU SESSION RESOURCE MODIFY RESPONSE message sent from the NG-RAN node to the AMF. The PDU Session Resource Modify Response Transfer IE may include a QoS Flow Add or Modify Response List IE. The QoS Flow Add or Modify Response List IE indicates a list of QoS flows added or modified by the NG-RAN node. The QoS Flow Add or Modify Response List IE includes a QoS Flow Identifier IE for each QoS flow included in the list. In addition, the QoS Flow Add or Modify Response List IE may include a Current QoS Parameters Set Index IE for each GBR QoS flow included in the list. The Current QoS Parameters Set Index IE indicates an index to the alternative QoS parameter set that is currently filled.

[0092] Furthermore, in the example of Figure 9, the QoS Flow Add or Modify Response List IE is extended to include a Cause IE for each GBR QoS flow included in the list. This Cause IE is used to indicate the reason, cause, or factor that led to the determination that the QoS profile of the added or modified GBR QoS flow is not satisfied. Therefore, in this example, the set of values ​​that the Cause IE can indicate as the radio network layer cause is extended compared to the existing set. The NG-RAN node 3 may set the Cause IE shown in Figure 9 to a value that indicates the reason, cause, or factor that led to the determination that the QoS profile of the added or modified GBR QoS flow is not satisfied.

[0093] For example, the Cause IE in FIG. 9 may indicate "radio link failure" or "RAN internal congestion." Additionally or alternatively, the Cause IE may indicate "AI / ML result." Additionally or alternatively, the Cause IE may indicate "bandwidth requested by other higher priority GBR QoS Flows."

[0094] Figure 10 shows an example of the format of the improved PDU Session Resource Setup Response Transfer IE. The PDU Session Resource Setup Response Transfer IE is included in the INITIAL CONTEXT SETUP RESPONSE message or the PDU SESSION RESOURCE SETUP RESPONSE message sent from the NG-RAN node to the AMF. The PDU Session Resource Setup Response Transfer IE may include a QoS Flow Setup Response List IE. The QoS Flow Setup Response List IE indicates a list of QoS flows set up by the NG-RAN node. The QoS Flow Setup Response List IE includes a QoS Flow Identifier IE for each QoS flow included in the list. In addition, the QoS Flow Setup Response List IE may include a Current QoS Parameters Set Index IE for each GBR QoS flow included in the list. The Current QoS Parameters Set Index IE indicates an index to the alternative QoS parameter set that is currently being satisfied.

[0095] Furthermore, in the example of Fig. 10, the QoS Flow Setup Response List IE is extended to include a Cause IE for each GBR QoS flow included in the list. This Cause IE is used to indicate the reason, cause, or factor that led to the determination that the QoS profile of the set-up GBR QoS flow is not satisfied. Therefore, in this example, the set of values ​​that the Cause IE can indicate as the radio network layer cause is extended compared to the existing set. The NG-RAN node 3 may set the Cause IE shown in Fig. 10 to a value that indicates the reason, cause, or factor that led to the determination that the QoS profile of the set-up GBR QoS flow is not satisfied.

[0096] For example, the Cause IE in FIG. 10 may indicate "radio link failure" or "RAN internal congestion." Additionally or alternatively, the Cause IE may indicate "AI / ML result." Additionally or alternatively, the Cause IE may indicate "bandwidth requested by other higher priority GBR QoS Flows."

[0097] According to the operation described in this embodiment, a RAN node (e.g., NG-RAN node 3) can inform the core network of the reason (or cause, or factor) that led to the decision on the QoS notification control information (i.e., notification that the QoS profile (e.g., GFBR) of a packet flow is not satisfied or will be satisfied again). The notification of this reason, cause, or factor may be useful for the core network (e.g., SMF 6 or PCF 7, or both) to optimize the action to be taken with respect to the packet flow (e.g., QoS flow).

[0098] For example, the core network may consider the reason, cause, or factor notification to determine an updated QoS profile for the packet flow. The core network may inform the RAN node of the updated QoS profile. In some implementations, the core network may use the reason, cause, or factor notification as input data to a trained AI / ML model for performing inference. Additionally or alternatively, the core network may utilize the reason, cause, or factor notification for training the AI / ML model.

[0099] Additionally or alternatively, the core network may change the action it takes with respect to a packet flow based on the content of the notification of the reason, cause, or factor that caused the determination that the QoS profile (e.g., GFBR) of the packet flow is not satisfied or is again satisfied. In some implementations, based on the content of the notification of the reason, cause, or factor, the core network (e.g., SMF 6 or PCF 7, or both) may change the degree of throttling that it requests the application function (AF) to reduce the downlink GFBR of the packet flow. Additionally or alternatively, based on the content of the notification of the reason, cause, or factor, the core network (e.g., SMF 6 or PCF 7, or both) may determine whether to request the application function (AF) to reduce the downlink GFBR of the packet flow.

[0100] Second Embodiment A configuration example of a wireless communication system according to this embodiment is similar to the configuration example described with reference to Fig. 1. This embodiment provides an improvement in QoS notification control.

[0101] Figure 11 shows an example of the operation of a RAN node. The RAN node may be the NG-RAN node 3 shown in Figure 1. In step 1101, the RAN node receives a QoS profile for a packet flow from a core network. The core network may be the 5GC 4 shown in Figure 1. The packet flow may be a QoS flow in a PDU session. The RAN node may receive the QoS profile for the packet flow in an initial context setup procedure, a PDU session resource setup procedure, or a PDU session resource modification procedure. The QoS profile may include QoS parameters including 5QI, ARP, and GBFR. The QoS profile includes a notification control parameter, which may indicate that notification control is enabled for the QoS flow.

[0102] In step 1102, upon sending a notification to the core network that the QoS profile is no longer satisfied or is again satisfied while maintaining the packet flow, the RAN node also informs the core network of the RAN node's preferred values ​​for one or more QoS parameters for the packet flow, which may include at least one of GFBR, 5QI, PDB, or PER.

[0103] As already explained, if the RAN node has received a list of alternative QoS profiles in addition to the QoS profile for the packet flow, a situation in which a QoS profile is no longer satisfied may be a situation in which any of the alternative QoS profiles are satisfied, or it may be a situation in which even the lowest priority alternative QoS profile cannot be satisfied.

[0104] The RAN node may determine preferred values ​​of one or more QoS parameters on its own. In some implementations, the RAN node may determine preferred values ​​of one or more QoS parameters on its own through inference using a trained AI or ML model. Alternatively, the RAN node may determine preferred values ​​of one or more QoS parameters based on information received from another control node. Alternatively, the RAN node may receive preferred values ​​of one or more QoS parameters from another control node. The other control node may determine preferred values ​​of one or more QoS parameters through inference using a trained AI or ML model. The other control node may be a Near-RT RIC or a Non-RT RIC.

[0105] The RAN node may send the notification of step 1102 using a PDU Session Resource Notify procedure. Specifically, the RAN node may use a PDU SESSION RESOURCE NOTIFY message for the notification of step 1102, which includes an indication of the QoS parameter values ​​preferred by the RAN node. Alternatively, the RAN node may send the notification of step 1102 in an initial context setup procedure, a PDU session resource setup procedure, or a PDU session resource modification procedure. In this case, the RAN node may use an INITIAL CONTEXT SETUP RESPONSE, a PDU SESSION RESOURCE SETUP RESPONSE, or a PDU SESSION RESOURCE MODIFY RESPONSE message for the notification of step 1102, which includes an indication of the QoS parameter values ​​preferred by the RAN node.

[0106] Figure 12 shows an example of the operation of a core network node related to the operation of the RAN node shown in Figure 11. The core network node may be the AMF 5 or SMF 6 shown in Figure 1. In step 1201, the core network node sends a QoS profile for a packet flow (e.g., QoS flow) to the RAN node. The RAN node may be the NG-RAN node 3 shown in Figure 1. The core network node (e.g., SMF 6) may send the QoS profile to the RAN node via another core network node (e.g., AMF 5). The core network node may send the QoS profile for the packet flow in an initial context setup procedure, a PDU session resource setup procedure, or a PDU session resource modification procedure. The QoS profile may include QoS parameters including 5QI, ARP, and GBFR. The QoS profile includes a notification control parameter, which may indicate that notification control is enabled for the QoS flow.

[0107] In step 1202, the core network node receives a first notification from the RAN node that the packet flow is maintained but the QoS profile is no longer satisfied or is again satisfied, along with a second notification indicating values ​​preferred by the RAN node for one or more QoS parameters for the packet flow. These one or more QoS parameters may include at least one of GFBR, 5QI, PDB, or PER. The core network node (e.g., SMF 6) may receive the first and second notifications from the RAN node via another core network node (e.g., AMF 5 or UPF 8). The message or information field containing or indicating the first and second notifications of step 1202 may be sent in a PDU Session Resource Notify procedure, an Initial Context Setup procedure, a PDU Session Resource Setup procedure, or a PDU Session Resource Modification procedure.

[0108] Figure 13 shows an example of signaling between a RAN node 1310 and a core network node 1320. The RAN node 1310 may be the NG-RAN node 3 shown in Figure 1. The core network node 1320 may be the AMF 5, SMF 6, or UPF 8 shown in Figure 1. In step 1301, the RAN node 1310 sends a control message or information field to the core network node 1320. The control message or information field indicates that the QoS profile of a (GBR) packet flow is not met or is met again, along with values ​​preferred by the RAN node 1310 for one or more QoS parameters for the packet flow. The RAN node 1310 (e.g., NG-RAN node 3) may send the control message or information field to the core network node 1320 (e.g., SMF 6) via another core network node (e.g., AMF 5 or UPF 8).

[0109] The control message or information field of step 1301 may be sent in a notification control procedure (e.g., PDU Session Resource Notify procedure). Specifically, when sending a control message or information field indicating that the QoS profile of a packet flow (e.g., QoS flow) is not met or will be met again during the lifetime of the packet flow, i.e., while the packet flow is established and maintained, the RAN node 1310 may include one or more preferred QoS parameter values ​​in the control message or information field.

[0110] Alternatively, the control message or information field of step 1301 may be sent during a procedure involving the establishment or setup of a new packet flow. These procedures include, for example, an initial context setup procedure, a PDU session resource setup procedure, and a PDU session resource modification procedure. Specifically, when sending a response message indicating acceptance of the establishment or setup of a new packet flow, the RAN node 1310 may include in the response message a notification indicating that the QoS profile of the packet flow is not satisfied but that an alternative QoS profile is satisfied. In addition, the RAN node 1310 may include one or more preferred QoS parameter values ​​in the control message or information field.

[0111] Alternatively, the control message or information field of step 1301 may be sent in a procedure involving modification of an established packet flow (e.g., modification of a QoS profile). These procedures include, for example, a PDU session resource modification procedure. Specifically, when sending a response message indicating acceptance of the packet flow modification, the RAN node 1310 may include in the response message a notification indicating that the QoS profile of the packet flow cannot be satisfied but that an alternative QoS profile can be satisfied. In addition, the RAN node 1310 may include one or more preferred QoS parameter values ​​in the control message or information field.

[0112] Figure 14 shows an example of signaling between a RAN node 1410 and a core network node 1420. The RAN node 1410 may be the NG-RAN node 3 shown in Figure 1. The core network node 1420 may be the AMF 5 shown in Figure 1. The signaling in Figure 14 is a specific example of the signaling in Figure 13. In step 1401, the RAN node 1410 sends a PDU SESSION RESOURCE NOTIFY message to the core network node 1420. The PDU SESSION RESOURCE NOTIFY message indicates that the QoS profile of a (GBR) QoS flow is not satisfied or is satisfied again, along with values ​​preferred by the RAN node 1410 for one or more QoS parameters for the QoS flow. The core network node 1420 (e.g., AMF 5) may forward these notifications or indications received from the RAN node 1410 to other core network nodes (e.g., SMF 6 or PCF 7).

[0113] Figure 15 shows an example of signaling between a RAN node 1510 and a core network node 1520. The RAN node 1510 may be the NG-RAN node 3 shown in Figure 1. The core network node 1520 may be the AMF 5 shown in Figure 1. The signaling in Figure 15 is a specific example of the signaling in Figure 13. In step 1501, the RAN node 1510 sends an INITIAL CONTEXT SETUP RESPONSE, a PDU SESSION RESOURCE SETUP RESPONSE, or a PDU SESSION RESOURCE MODIFY RESPONSE message to the core network node 1520. The message indicates that the QoS profile of a (GBR) QoS flow is not satisfied, along with values ​​preferred by the RAN node 1510 for one or more QoS parameters for the QoS flow. The core network node 1520 (eg, AMF 5) may forward these notifications or indications received from the RAN node 1510 to other core network nodes (eg, SMF 6 or PCF 7).

[0114] Figure 16 shows an example of the format of the improved PDU Session Resource Notify Transfer IE. The PDU Session Resource Notify Transfer IE is included in a PDU SESSION RESOURCE NOTIFY message sent from the NG-RAN node to the AMF. The PDU Session Resource Notify Transfer IE may include a QoS Flow Notify List IE. The QoS Flow Notify List IE indicates a list of GBR QoS flows that are no longer fulfilled or to be fulfilled again by the NG-RAN node. The QoS Flow Notify List IE includes a QoS Flow Identifier IE and a Notification Cause IE for each QoS flow included in the list. The Notification Cause IE is of enumeration type and can indicate "fulfilled" or "not fulfilled." In addition, the QoS Flow Notify List IE may include a Current QoS Parameters Set Index IE for each GBR QoS flow included in the list. The Current QoS Parameters Set Index IE indicates an index to the alternative QoS parameter set that is currently fulfilled.

[0115] Furthermore, in the example of Figure 16, the QoS Flow Notify List IE is extended to include, for each GBR QoS flow included in the list, a Preferred GFBR IE, a Preferred PDB IE, and a Preferred PER IE, which can be used to indicate the preferred GFBR, PDB, and PER values ​​for the GBR QoS flow to a RAN node (e.g., NG-RAN node 3).

[0116] Figure 17 shows an example of the format of the improved PDU Session Resource Modify Response Transfer IE. The PDU Session Resource Modify Response Transfer IE is included in a PDU SESSION RESOURCE MODIFY RESPONSE message sent from the NG-RAN node to the AMF. The PDU Session Resource Modify Response Transfer IE may include a QoS Flow Add or Modify Response List IE. The QoS Flow Add or Modify Response List IE indicates a list of QoS flows added or modified by the NG-RAN node. The QoS Flow Add or Modify Response List IE includes a QoS Flow Identifier IE for each QoS flow included in the list. In addition, the QoS Flow Add or Modify Response List IE may include a Current QoS Parameters Set Index IE for each GBR QoS flow included in the list. The Current QoS Parameters Set Index IE indicates an index to the alternative QoS parameter set that is currently filled.

[0117] Furthermore, in the example of Figure 17, the QoS Flow Add or Modify Response List IE is extended to include, for each GBR QoS flow included in the list, a Preferred GFBR IE, a Preferred PDB IE, and a Preferred PER IE, which can be used to indicate the preferred GFBR, PDB, and PER values ​​for the GBR QoS flow to a RAN node (e.g., NG-RAN node 3).

[0118] Figure 18 shows an example of the format of the improved PDU Session Resource Setup Response Transfer IE. The PDU Session Resource Setup Response Transfer IE is included in the INITIAL CONTEXT SETUP RESPONSE message or the PDU SESSION RESOURCE SETUP RESPONSE message sent from the NG-RAN node to the AMF. The PDU Session Resource Setup Response Transfer IE may include a QoS Flow Setup Response List IE. The QoS Flow Setup Response List IE indicates a list of QoS flows set up by the NG-RAN node. The QoS Flow Setup Response List IE includes a QoS Flow Identifier IE for each QoS flow included in the list. In addition, the QoS Flow Setup Response List IE may include a Current QoS Parameters Set Index IE for each GBR QoS flow included in the list. The Current QoS Parameters Set Index IE indicates an index to the alternative QoS parameter set that is currently being satisfied.

[0119] Furthermore, in the example of Figure 18, the QoS Flow Setup Response List IE is extended to include, for each GBR QoS flow included in the list, a Preferred GFBR IE, a Preferred PDB IE, and a Preferred PER IE, which can be used to indicate the preferred GFBR, PDB, and PER values ​​for the GBR QoS flow to the RAN node (e.g., NG-RAN node 3).

[0120] According to the operation described in this embodiment, when a RAN node (e.g., NG-RAN node 3) sends QoS notification control information (i.e., notification that the QoS profile (e.g., GFBR) of the packet flow is not satisfied or will be satisfied again) for a packet flow, the RAN node can inform the core network of QoS parameter values ​​preferred by the RAN node for the packet flow. Notification of the QoS parameter values ​​preferred by the RAN node can be useful for the core network (e.g., SMF 6 or PCF 7, or both) to optimize the actions to be taken with respect to the packet flow (e.g., QoS flow).

[0121] For example, the core network may consider signaling preferred QoS parameter values ​​for the RAN node to determine an updated QoS profile for the packet flow. The core network may inform the RAN node of the updated QoS profile. In some implementations, the core network may use the preferred QoS parameter values ​​for the RAN node as input data to a trained AI / ML model for performing inference. Additionally or alternatively, the core network may use the preferred QoS parameter values ​​for the RAN node for training an AI / ML model.

[0122] For example, when notifying the core network that a GBR QoS flow has transitioned from a state where an alternative QoS profile is satisfied to a state where a (non-alternative) QoS profile is satisfied, the NG-RAN node may also notify the core network of a more preferred GFBR value, PDB value, or PER value, or any combination thereof. The more preferred GFBR value, PDB value, and PER value may be better than the GFBR value, PDB value, and PER value specified in the (non-alternative) QoS profile for the GBR QoS flow. In this case, the core network (e.g., SMF6 or PCF7, or both) may set a higher GFBR value, a lower PDB value, or a lower PER value for the GBR QoS flow based on the notification from the NG-RAN node. Alternatively, the core network (e.g., SMF6 or PCF7, or both) may request the AF to increase the downlink GFBR for the GBR QoS flow. This can contribute to efficient resource utilization in the NG-RAN2 and 5GC4.

[0123] Next, exemplary configurations of RAN nodes and core network nodes related to the above-described embodiments will be described below. FIG. 19 is a block diagram showing an exemplary configuration of an NG-RAN node 3. The configurations of other RAN nodes such as 410 and 510 may be similar to the configuration shown in FIG. 19. Referring to FIG. 19, the NG-RAN node 3 includes a Radio Frequency (RF) transceiver 1901, a network interface 1903, a processor 1904, and a memory 1905. The RF transceiver 1901 performs analog RF signal processing for communication with UEs, including UE1. The RF transceiver 1901 may include multiple transceivers. The RF transceiver 1901 is coupled to an antenna array 1902 and a processor 1904. The RF transceiver 1901 receives modulation symbol data from the processor 1904, generates a transmit RF signal, and provides the transmit RF signal to the antenna array 1902. The RF transceiver 1901 also generates a baseband receive signal based on the receive RF signal received by the antenna array 1902 and supplies the baseband receive signal to the processor 1904. The RF transceiver 1901 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, multiple phase shifters and multiple power amplifiers.

[0124] The network interface 1903 is used to communicate with network nodes (e.g., other RAN nodes, as well as nodes within the 5GC 4). The network interface 1903 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0125] The processor 1904 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. The processor 1904 may include multiple processors. For example, the processor 1904 may include a modem processor (e.g., a Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., a Central Processing Unit (CPU) or a Micro Processing Unit (MPU)) that performs control plane processing.

[0126] For example, digital baseband signal processing by processor 1904 may include signal processing for a Service Data Adaptation Protocol (SDAP) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. Also, control plane processing by processor 1904 may include processing of Non-Access Stratum (NAS) messages, RRC messages, MAC Control Elements (CEs), and Downlink Control Information (DCI).

[0127] The processor 1904 may include a digital beamformer module for beamforming, which may include a Multiple Input Multiple Output (MIMO) encoder and precoder.

[0128] The memory 1905 is configured by a combination of volatile memory and non-volatile memory. The volatile memory is, for example, Static Random Access Memory (SRAM), Dynamic RAM (DRAM), or a combination thereof. The non-volatile memory is, for example, Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or a hard disk drive, or any combination thereof. The memory 1905 may include storage located remotely from the processor 1904. In this case, the processor 1904 may access the memory 1905 via the network interface 1903 or an I / O interface (not shown).

[0129] The memory 1905 may store one or more software modules (computer programs) 1906 including instructions and data for performing the processing by the NG-RAN node 3 described in the above-described embodiments. In some implementations, the processor 1904 may be configured to read and execute the software modules 1906 from the memory 1905 to perform the processing by the NG-RAN node 3 described in the above-described embodiments.

[0130] The control plane processing and operations performed by the NG-RAN node 3 described in the above embodiments may be realized by a processor 1904 and a memory 1905 storing software modules 1906.

[0131] If the NG-RAN node 3 is a CU (e.g., eNB-CU or gNB-CU) or a CU-CP, the NG-RAN node 3 may not include the RF transceiver 1901 (and antenna array 1902).

[0132] Fig. 20 shows an example configuration of the AMF 5. The configurations of other core network nodes such as the SMF 6, PCF 7, and UPF 8 may also be similar to the configuration shown in Fig. 20. Referring to Fig. 20, the AMF 5 includes a network interface 2001, a processor 2002, and a memory 2003.

[0133] The network interface 2001 is used, for example, to communicate with other network functions (NFs) or nodes, and may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0134] The processor 2002 may be, for example, a microprocessor, an MPU, or a CPU. The processor 2002 may include multiple processors.

[0135] The memory 2003 is composed of volatile memory and nonvolatile memory. The memory 2003 may include a plurality of physically independent memory devices. The volatile memory is, for example, SRAM or DRAM, or a combination thereof. The nonvolatile memory is, for example, MROM, EEPROM, flash memory, or a hard disk drive, or any combination thereof. The memory 2003 may include storage located remotely from the processor 2002. In this case, the processor 2002 may access the memory 2003 via the network interface 2001 or the I / O interface.

[0136] The memory 2003 may store one or more software modules (computer programs) 2004 including instructions and data for performing processing by the AMF 5 described in the above-described embodiments. In some implementations, the processor 2002 may be configured to read and execute the software modules 2004 from the memory 2003, thereby performing the processing of the AMF 5 described in the above-described embodiments.

[0137] As described with reference to Figures 19 and 20, each of the processors included in the RAN node and the core network node according to the above-described embodiments may execute one or more programs including instructions for causing a computer to perform the algorithms described with reference to the drawings. The programs include instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The programs may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable media or tangible storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disk (DVD), Blu-ray disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The programs may also be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0138] Furthermore, the above-described embodiments are merely examples of application of the technical ideas obtained by the inventors of the present invention. In other words, the technical ideas are not limited to the above-described embodiments, and various modifications are possible.

[0139] For example, some or all of the above embodiments may also be described as, but are not limited to, the following appendices. Some or all of the elements (e.g., configurations and functions) described in appendices directed to an apparatus (e.g., a RAN node) may naturally also be described as appendices directed to a method and a program. Some or all of the elements described in any appendice may be applied to various hardware, software, recording means for recording software, systems, and methods.

[0140] (Supplementary Note 1) A radio access network node comprising: means for receiving a Quality of Service (QoS) profile for a packet flow from a core network; and means for notifying the core network of a reason, cause, or factor that led to a determination that the QoS profile is no longer satisfied or will be satisfied again, when sending a notification to the core network that the QoS profile is no longer satisfied or will be satisfied again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow. (Supplementary Note 2) The radio access network node of Supplementary Note 1, wherein the notifying means is adapted to use a PDU SESSION RESOURCE NOTIFY message to indicate the reason, cause, or factor to the core network. (Supplementary Note 3) The radio access network node of Supplementary Note 2, wherein the notifying means is adapted to set a value indicating the reason, cause, or factor in a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 4) The radio access network node according to Supplementary Note 2, wherein the notifying means is adapted to set a value indicating the reason, cause or factor in a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 5) The radio access network node according to Supplementary Note 1, wherein the notifying means is adapted to use an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate the reason, cause or factor to the core network.(Supplementary Note 6) The radio access network node according to any one of Supplements 1 to 5, wherein the reason, cause, or factor includes a reason, cause, or factor due to queuing delay or system load measurements. (Supplementary Note 7) The radio access network node according to any one of Supplements 1 to 5, wherein the reason, cause, or factor includes a reason, cause, or factor due to radio link failure, radio access network internal congestion, or due to artificial intelligence or machine learning inference results. (Supplementary Note 8) The radio access network node according to any one of Supplements 1 to 7, wherein a situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network is satisfied, or a situation in which even the lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied. (Supplementary Note 9) The radio access network node according to any one of Supplements 1 to 8, wherein notification of the reason, cause, or factor is taken into account by the core network for determining an updated QoS profile for the packet flow. (Supplementary Note 10) The radio access network node according to any one of Supplements 1 to 9, wherein the notification of the reason, cause or factor causes the core network to determine an updated QoS profile for the packet flow and notify the radio access network node. (Supplementary Note 11) The radio access network node according to any one of Supplements 1 to 10, wherein the notifying means is adapted, upon sending a notification to the core network that the QoS profile is no longer satisfied, to further indicate to the core network values ​​preferred by the radio access network node of one or more QoS parameters for the packet flow. (Supplementary Note 12) The radio access network node according to Supplementary Note 11, wherein the one or more QoS parameters include at least one of Guaranteed Flow Bit Rate (GBFR), 5G QoS Identifier (5QI), Packet Delay Budget (PDB), or Packet Error Rate (PER).(Supplementary Note 13) The radio access network node according to Supplementary Note 11 or 12, further comprising: means for generating a notification indicating preferred values ​​of the one or more QoS parameters based on results of inference based on artificial intelligence or machine learning received from a Radio Access Network (RAN) Intelligent Controller (RIC). (Supplementary Note 14) The radio access network node according to any one of Supplements 11 to 13, wherein the notification of preferred values ​​of the one or more QoS parameters is taken into account by the core network to determine an updated QoS profile for the packet flow. (Supplementary Note 15) The radio access network node according to any one of Supplements 11 to 14, wherein the notification of preferred values ​​of the one or more QoS parameters causes the core network to determine an updated QoS profile for the packet flow and inform the radio access network node. (Supplementary Note 16) The radio access network node according to any one of Supplements 1 to 15, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session. (Supplementary Note 17) The radio access network node according to any one of Supplementary Notes 1 to 16, wherein the QoS profile comprises QoS parameters including a 5G QoS Identifier (5QI), an Allocation and Retention Priority (ARP), and a Guaranteed Flow Bit Rate (GBFR).(Supplementary Note 18) A method performed by a radio access network node, comprising: receiving from a core network a Quality of Service (QoS) profile for a packet flow; and when sending a notification to the core network that the QoS profile is no longer satisfied or the QoS profile will be satisfied again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow, also notifying the core network of a reason, cause, or factor that led to the determination that the QoS profile is no longer satisfied or will be satisfied again. (Supplementary Note 19) The method of Supplementary Note 18, wherein the notifying comprises using a PDU SESSION RESOURCE NOTIFY message to indicate the reason, cause, or factor to the core network. (Supplementary Note 20) The method of Supplementary Note 19, wherein the notifying comprises setting a value indicating the reason, cause, or factor in a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 21) The method of Supplementary Note 19, wherein the notifying comprises setting a value indicating the reason, cause, or factor in a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 22) The method of Supplementary Note 18, wherein the notifying comprises using an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate the reason, cause, or factor to the core network.(Supplementary note 23) The method of any one of Supplements 18 to 22, wherein the reason, cause, or factor includes a reason, cause, or factor due to queuing delay or system load measurements. (Supplementary note 24) The method of any one of Supplements 18 to 22, wherein the reason, cause, or factor includes a reason, cause, or factor due to radio link failure, radio access network internal congestion, or due to artificial intelligence or machine learning inference results. (Supplementary note 25) The method of any one of Supplements 18 to 24, wherein the situation where the QoS profile is no longer satisfied includes a situation where any of one or more alternative QoS profiles provided by the core network is satisfied, or a situation where even the lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied. (Supplementary note 26) The method of any one of Supplements 18 to 25, wherein notification of the reason, cause, or factor is taken into account by the core network to determine an updated QoS profile for the packet flow. Supplementary Note 27: The method of any one of Supplements 18 to 26, wherein the notification of the reason, cause, or factor causes the core network to determine an updated QoS profile for the packet flow and inform the radio access network node. Supplementary Note 28: The method of any one of Supplements 18 to 27, further comprising, when sending notification to the core network that the QoS profile is no longer satisfied, indicating to the core network preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow. Supplementary Note 29: The method of Supplementary Note 28, wherein the one or more QoS parameters include at least one of Guaranteed Flow Bit Rate (GBFR), 5G QoS Identifier (5QI), Packet Delay Budget (PDB), or Packet Error Rate (PER).(Supplementary Note 30) The method of Supplementary Note 28 or 29, further comprising generating a notification indicating preferred values ​​of the one or more QoS parameters based on results of artificial intelligence or machine learning based inference received from a Radio Access Network (RAN) Intelligent Controller (RIC). (Supplementary Note 31) The method of any one of Supplements 28 to 30, wherein the notification of preferred values ​​of the one or more QoS parameters is taken into account by the core network to determine an updated QoS profile for the packet flow. (Supplementary Note 32) The method of any one of Supplements 28 to 31, wherein the notification of preferred values ​​of the one or more QoS parameters causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow. (Supplementary Note 33) The method of any one of Supplements 18 to 32, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session. (Supplementary Note 34) The method according to any one of Supplements 18 to 33, wherein the QoS profile comprises QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR). (Supplementary Note 35) A program for causing a computer to perform a method for a radio access network node, the method comprising: receiving from a core network a Quality of Service (QoS) profile for a packet flow; and when sending a notification to the core network that the QoS profile is no longer satisfied or that the QoS profile will be satisfied again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow, also notifying the core network of reasons, causes, or factors that led to a determination that the QoS profile is no longer satisfied or that the QoS profile will be satisfied again.(Supplementary Note 36) The program according to Supplementary Note 35, wherein the notifying comprises using a PDU SESSION RESOURCE NOTIFY message to indicate the reason, cause, or factor to the core network. (Supplementary Note 37) The program according to Supplementary Note 36, wherein the notifying comprises setting a value indicating the reason, cause, or factor in a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 38) The program according to Supplementary Note 36, wherein the notifying comprises setting a value indicating the reason, cause, or factor in a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 39) The program of Supplementary Note 35, wherein the informing includes using an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate the reason, cause, or factor to the core network. (Supplementary Note 40) The program of any one of Supplements 35 to 39, wherein the reason, cause, or factor includes a reason, cause, or factor due to a measurement of queuing delay or system load. (Supplementary Note 41) The program of any one of Supplements 35 to 39, wherein the reason, cause, or factor includes a reason, cause, or factor due to a radio link failure, a radio access network internal congestion, or a result of inference from artificial intelligence or machine learning.(Supplementary Note 42) The program of any one of Supplements 35 to 41, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network is satisfied, or a situation in which even a lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied. (Supplementary Note 43) The program of any one of Supplements 35 to 42, wherein the notification of the reason, cause, or factor is taken into account by the core network to determine an updated QoS profile for the packet flow. (Supplementary Note 44) The program of any one of Supplements 35 to 43, wherein the notification of the reason, cause, or factor causes the core network to determine an updated QoS profile for the packet flow and inform the radio access network node of the updated QoS profile. (Supplementary Note 45) The program of any one of Supplements 35 to 44, wherein the method further comprises, when sending a notification to the core network that the QoS profile is no longer satisfied, indicating to the core network preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow. (Supplementary Note 46) The program of Supplementary Note 45, wherein the one or more QoS parameters include at least one of Guaranteed Flow Bit Rate (GBFR), 5G QoS Identifier (5QI), Packet Delay Budget (PDB), or Packet Error Rate (PER). (Supplementary Note 47) The program of Supplementary Note 45 or 46, wherein the method further comprises generating a notification indicating preferred values ​​of the one or more QoS parameters based on results of artificial intelligence or machine learning inference received from a Radio Access Network (RAN) Intelligent Controller (RIC).(Supplementary Note 48) The program of any one of Supplements 45 to 47, wherein the notification of preferred values ​​of the one or more QoS parameters is taken into account by the core network to determine an updated QoS profile for the packet flow. (Supplementary Note 49) The program of any one of Supplements 45 to 48, wherein the notification of preferred values ​​of the one or more QoS parameters causes the core network to determine an updated QoS profile for the packet flow and inform the radio access network node. (Supplementary Note 50) The program of any one of Supplements 35 to 49, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session. (Supplementary Note 51) The program of any one of Supplements 35 to 49, wherein the QoS profile includes QoS parameters including 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR). 52. A core network node according to claim 52, comprising: means for sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and means for receiving from the radio access network node a first indication that the packet flow is not released or the setup or modification of the packet flow is not rejected, and the packet flow is maintained but the QoS profile is no longer met or the QoS profile is once again met, together with a second indication of reasons, causes or factors that led to a determination that the QoS profile is no longer met or is once again met. 53. The core network node according to claim 52, wherein the receiving means is adapted to receive a PDU SESSION RESOURCE NOTIFY message containing the first and second indications.(Supplementary Note 54) The core network node according to Supplementary Note 53, wherein the first and second notifications are both indicated by a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 55) The core network node according to Supplementary Note 53, wherein the second notification is indicated by a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 56) The core network node according to Supplementary Note 52, wherein the receiving means is adapted to receive an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message containing the first and second notifications. (Supplementary Note 57) The core network node of Supplementary Note 52, wherein the receiving means is adapted to receive the first and second notifications via one or more other core network nodes. (Supplementary Note 58) The core network node of any one of Supplements 52 to 57, wherein the reason, cause or factor includes a reason, cause or factor due to a measurement of queuing delay or system load. (Supplementary Note 59) The core network node of any one of Supplements 52 to 57, wherein the reason, cause or factor includes a reason, cause or factor due to a radio link failure, a radio access network internal congestion, or a result of artificial intelligence or machine learning inference.60. The core network node of any one of Supplements 52 to 59, wherein the situation where the QoS profile is no longer satisfied includes a situation where any of one or more alternative QoS profiles provided by the core network node is satisfied, or a situation where even a lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied. 61. The core network node of any one of Supplements 52 to 60, further comprising: means for taking the indication of the reason, cause or factor into account for determining an updated QoS profile for the packet flow. 62. The core network node of Supplement 61, further comprising means for informing the radio access network node of the updated QoS profile. 63. The core network node of any one of Supplements 52 to 62, wherein the receiving means is adapted to receive from the radio access network node, together with the first and second indications, a third indication indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow. (Supplementary Note 64) The core network node of Supplementary Note 63, wherein the one or more QoS parameters comprise at least one of Guaranteed Flow Bit Rate (GBFR), 5G QoS Identifier (5QI), Packet Delay Budget (PDB), or Packet Error Rate (PER). (Supplementary Note 65) The core network node of Supplementary Note 63 or 64, further comprising means for taking into account preferred values ​​of the one or more QoS parameters for determining an updated QoS profile for the packet flow. (Supplementary Note 66) The core network node of Supplementary Note 65, further comprising means for signaling the updated QoS profile to the radio access network node.67. The core network node of any one of Supplements 52 to 66, wherein the packet flow is a Quality of Service (QoS) flow comprised in a protocol data unit (PDU) session. 68. The core network node of any one of Supplements 52 to 67, wherein the QoS profile comprises QoS parameters including a 5G QoS Identifier (5QI), an Allocation and Retention Priority (ARP), and a Guaranteed Flow Bit Rate (GBFR). 69. A method performed by a core network node, comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving from the radio access network node a first indication that the packet flow is not released or that the setup or modification of the packet flow is not rejected and the packet flow is maintained but the QoS profile is no longer met or the QoS profile is again met, together with a second indication of reasons, causes, or factors that led to a determination that the QoS profile is no longer met or is again met. (Supplementary Note 70) The method of Supplementary Note 69, wherein said receiving includes receiving a PDU SESSION RESOURCE NOTIFY message containing the first and second notifications. (Supplementary Note 71) The method of Supplementary Note 70, wherein said first and second notifications are both indicated by a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in said PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 72) The method of Supplementary Note 70, wherein said second notification is indicated by a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in said PDU SESSION RESOURCE NOTIFY message.(Supplementary Note 73) The method of Supplementary Note 69, wherein the receiving includes receiving an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message containing the first and second notifications. (Supplementary Note 74) The method of Supplementary Note 69, wherein the receiving includes receiving the first and second notifications via one or more other core network nodes. (Supplementary Note 75) The method of any one of Supplements 69 to 74, wherein the reason, cause, or factor includes a reason, cause, or factor due to a measurement of queuing delay or system load. (Supplementary Note 76) The method of any one of Supplements 69 to 74, wherein the reason, cause, or factor includes a reason, cause, or factor due to a radio link failure, a radio access network internal congestion, or an inference result of artificial intelligence or machine learning. 77. The method of any one of Supplements 69 to 76, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network node is satisfied, or a situation in which even a lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied. 78. The method of any one of Supplements 69 to 77, further comprising taking the indication of the reason, cause, or factor into consideration for determining an updated QoS profile for the packet flow. 79. The method of Supplement 78, further comprising informing the radio access network node of the updated QoS profile. 80. The method of any one of Supplements 69 to 79, wherein the receiving includes receiving, together with the first and second indications, a third indication from the radio access network node indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.81. The method of claim 80, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER). 82. The method of claim 80 or 81, further comprising taking preferred values ​​of the one or more QoS parameters into account for determining an updated QoS profile for the packet flow. 83. The method of claim 82, further comprising informing the radio access network node of the updated QoS profile. 84. The method of any one of claims 69 to 83, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session. (Supplementary Note 85) The method of any one of Supplements 69 to 84, wherein the QoS profile comprises QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR). (Supplementary Note 86) A program product for causing a computer to perform a method for a core network node, the method comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving from the radio access network node a first notification that the packet flow is not released or the setup or modification of the packet flow is not rejected and the packet flow is maintained but the QoS profile is no longer met or the QoS profile is again met, together with a second notification of reasons, causes, or factors that led to a determination that the QoS profile is no longer met or is again met.(Supplementary Note 87) The program according to Supplementary Note 86, wherein the receiving includes receiving a PDU SESSION RESOURCE NOTIFY message including the first and second notifications. (Supplementary Note 88) The program according to Supplementary Note 87, wherein the first and second notifications are both indicated by a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 89) The program according to Supplementary Note 87, wherein the second notification is indicated by a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message. (Supplementary Note 90) The program of Supplementary Note 86, wherein the receiving includes receiving an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message containing the first and second notifications. (Supplementary Note 91) The program of Supplementary Note 86, wherein the receiving includes receiving the first and second notifications via one or more other core network nodes. (Supplementary Note 92) The program of any one of Supplements 86 to 91, wherein the reason, cause, or factor includes a reason, cause, or factor due to a measurement of queuing delay or system load. (Supplementary Note 93) The program of any one of Supplements 86 to 91, wherein the reason, cause, or factor includes a reason, cause, or factor due to a radio link failure, a radio access network internal congestion, or an inference result of artificial intelligence or machine learning.(Supplementary Note 94) The program of any one of Supplements 86 to 93, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network node is satisfied, or a situation in which even a lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied. (Supplementary Note 95) The program of any one of Supplements 86 to 94, wherein the method further comprises taking the indication of the reason, cause, or factor into consideration for determining an updated QoS profile for the packet flow. (Supplementary Note 96) The program of Supplementary Note 95, wherein the method further comprises informing the radio access network node of the updated QoS profile. (Supplementary Note 97) The program of any one of Supplements 86 to 96, wherein the receiving includes receiving, together with the first and second indications, a third indication from the radio access network node indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow. (Supplementary Note 98) The program of Supplementary Note 97, wherein the one or more QoS parameters include at least one of Guaranteed Flow Bit Rate (GBFR), 5G QoS Identifier (5QI), Packet Delay Budget (PDB), or Packet Error Rate (PER). (Supplementary Note 99) The program of Supplementary Note 97 or 98, wherein the method further comprises considering preferred values ​​of the one or more QoS parameters to determine an updated QoS profile for the packet flow. (Supplementary Note 100) The program of Supplementary Note 99, wherein the method further comprises informing the radio access network node of the updated QoS profile. (Supplementary Note 101) The program of any one of Supplements 86 to 100, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session.(Supplementary Note 102) The program according to any one of Supplements 86 to 101, wherein the QoS profile includes QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and a Guaranteed Flow Bit Rate (GBFR). (Supplementary Note 103) A radio access network node comprising: means for receiving a Quality of Service (QoS) profile for a packet flow from a core network; and means for, when sending a notification to the core network that the QoS profile is no longer satisfied or that the QoS profile will be satisfied again while maintaining the packet flow, also informing the core network of values ​​preferred for the radio access network node of one or more QoS parameters for the packet flow. (Supplementary Note 104) The radio access network node according to Supplementary Note 103, wherein the one or more QoS parameters include at least one of Guaranteed Flow Bit Rate (GBFR), 5G QoS Identifier (5QI), Packet Delay Budget (PDB), or Packet Error Rate (PER). (Supplementary Note 105) The radio access network node according to Supplementary Note 103 or 104, further comprising means for generating a notification indicating preferred values ​​of the one or more QoS parameters based on results of artificial intelligence or machine learning based inference received from a Radio Access Network (RAN) Intelligent Controller (RIC). (Supplementary Note 106) The radio access network node according to any one of Supplementary Notes 103 to 105, wherein the notification of preferred values ​​of the one or more preferred QoS parameters is taken into account by the core network for determining an updated QoS profile for the packet flow.107. The radio access network node of any one of Supplements 103 to 106, wherein the notification of the preferred values ​​of the one or more preferred QoS parameters causes the core network to determine an updated QoS profile for the packet flow and to inform the radio access network node. 108. The radio access network node of any one of Supplements 104 to 107, wherein the informing means is adapted to use a PDU SESSION RESOURCE NOTIFY message to indicate the preferred values ​​of the one or more QoS parameters to the core network. 109. The radio access network node of any one of Supplements 103 to 108, wherein the informing means is adapted to use an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate the preferred values ​​of the one or more QoS parameters to the core network. (Supplementary Note 110) The radio access network node according to any one of Supplementary Notes 103 to 109, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session. (Supplementary Note 111) The radio access network node according to any one of Supplementary Notes 103 to 110, wherein the QoS profile includes QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and a Guaranteed Flow Bit Rate (GBFR).(Supplementary Note 112) A method performed by a radio access network node, the method comprising: receiving from a core network a Quality of Service (QoS) profile for a packet flow, and when sending a notification to the core network that the QoS profile is no longer satisfied or that the QoS profile will be satisfied again while maintaining the packet flow, also informing the core network of values ​​preferred for the radio access network node of one or more QoS parameters for the packet flow. (Supplementary Note 113) A program for causing a computer to perform a method for a radio access network node, the method comprising: receiving from the core network a Quality of Service (QoS) profile for a packet flow, and when sending a notification to the core network that the QoS profile is no longer satisfied or that the QoS profile will be satisfied again while maintaining the packet flow, also informing the core network of values ​​preferred for the radio access network node of one or more QoS parameters for the packet flow. 114. A core network node comprising: means for sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and means for receiving from the radio access network node a first indication that the packet flow is maintained but the QoS profile is no longer satisfied or that the QoS profile is again satisfied, together with a second indication indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow. 115. The core network node of claim 114, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).(Supplementary Note 116) The core network node of Supplementary Note 114 or 115, further comprising means for taking into account preferred values ​​of the one or more QoS parameters for determining an updated QoS profile for the packet flow. (Supplementary Note 117) The core network node of Supplementary Note 116, further comprising means for informing the radio access network node of the updated QoS profile. (Supplementary Note 118) The core network node of any one of Supplements 114 to 117, wherein the packet flow is a Quality of Service (QoS) flow comprised in a protocol data unit (PDU) session. (Supplementary Note 119) The core network node of any one of Supplements 114 to 118, wherein the QoS profile comprises QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR). (Supplementary Note 120) A method performed by a core network node, comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving a first notification from the radio access network node that the packet flow is maintained but the QoS profile is no longer satisfied or that the QoS profile is again satisfied, together with a second notification indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.(Supplementary Note 121) A program for causing a computer to perform a method for a core network node, comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving a first notification from the radio access network node that the packet flow is maintained but the QoS profile is no longer satisfied or that the QoS profile is again satisfied, together with a second notification indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

[0141] The above-described embodiments are merely examples of application of the technical ideas obtained by the inventors of the present invention. In other words, the technical ideas are not limited to the above-described embodiments, and various modifications are possible.

[0142] This application claims priority based on Japanese Patent Application No. 2023-126636, filed on August 2, 2023, the disclosure of which is incorporated herein in its entirety by reference.

[0143] 1 UE 2 NG-RAN 3 NG-RAN node 4 5GC 5 AMF 6 SMF 7 PCF 8 UPF 9 DN 1904 Processor 1905 Memory 1906 Modules 2002 Processor 2003 Memory 2004 Modules

Claims

1. A radio access network node comprising: means for receiving from a core network a Quality of Service (QoS) profile for a packet flow; and means for informing the core network of reasons, causes or factors that led to a determination that the QoS profile is no longer met or will be met again, when sending a notification to the core network that the QoS profile is no longer met or will be met again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow.

2. A radio access network node according to claim 1, wherein the means for informing is adapted to use a PDU SESSION RESOURCE NOTIFY message to indicate the reason, cause or factor to the core network.

3. The radio access network node of claim 2, wherein the notifying means is adapted to set a value indicative of the reason, cause or factor in a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

4. The radio access network node of claim 2, wherein the notifying means is adapted to set a value indicative of the reason, cause or factor in a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

5. A radio access network node according to claim 1, wherein the means for signalling is adapted to use an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate the reason, cause or factor to the core network.

6. A radio access network node according to any preceding claim, wherein the reasons, causes or factors include reasons, causes or factors according to measurements of queuing delay or system load.

7. A radio access network node according to any one of claims 1 to 5, wherein the reason, cause or factor includes a reason, cause or factor due to a radio link failure, due to radio access network internal congestion, or due to an inference result of artificial intelligence or machine learning.

8. A radio access network node according to any one of claims 1 to 7, wherein the situation in which the QoS profile is no longer satisfied comprises a situation in which any of one or more alternative QoS profiles provided by the core network is satisfied, or a situation in which even a lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied.

9. A radio access network node according to any preceding claim, wherein the indication of the reason, cause or factor is taken into account by the core network for determining an updated QoS profile for the packet flow.

10. A radio access network node according to any one of claims 1 to 9, wherein notification of the reason, cause or factor causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow.

11. A radio access network node according to any one of claims 1 to 10, wherein the informing means is adapted to further indicate to the core network, upon sending a notification to the core network that the QoS profile is no longer satisfied, values ​​preferred for the radio access network node of one or more QoS parameters for the packet flow.

12. The radio access network node of claim 11, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

13. A radio access network node according to claim 11 or 12, further comprising means for generating a notification indicating a preferred value of the one or more QoS parameters based on results of artificial intelligence or machine learning based inference received from a Radio Access Network (RAN) Intelligent Controller (RIC).

14. A radio access network node according to any one of claims 11 to 13, wherein the indication of the preferred values ​​of the one or more QoS parameters is taken into account by the core network for determining an updated QoS profile for the packet flow.

15. A radio access network node according to any one of claims 11 to 14, wherein the notification of the preferred values ​​of the one or more QoS parameters causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow.

16. A radio access network node according to any preceding claim, wherein the packet flow is a Quality of Service (QoS) flow contained in a protocol data unit (PDU) session.

17. A radio access network node according to any one of claims 1 to 16, wherein the QoS profile comprises QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

18. A method performed by a radio access network node comprising: receiving from a core network a Quality of Service (QoS) profile for a packet flow; and, when sending a notification to the core network that the QoS profile is no longer met or that the QoS profile will be met again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow, also informing the core network of the reasons, causes or factors that led to a determination that the QoS profile is no longer met or that the QoS profile will be met again.

19. The method of claim 18, wherein the informing includes using a PDU SESSION RESOURCE NOTIFY message to indicate the reason, cause, or factor to the core network.

20. The method of claim 19, wherein the notifying includes setting a value indicating the reason, cause, or factor in a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

21. The method of claim 19, wherein the notifying includes setting a value indicating the reason, cause, or factor in a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

22. The method of claim 18, wherein the informing includes using an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate the reason, cause, or factor to the core network.

23. A method according to any one of claims 18 to 22, wherein the reasons, causes or factors include reasons, causes or factors according to measurements of queuing delay or system load.

24. The method of any one of claims 18 to 22, wherein the reasons, causes, or factors include reasons, causes, or factors due to radio link failure, due to radio access network internal congestion, or due to artificial intelligence or machine learning inference results.

25. A method according to any one of claims 18 to 24, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network are satisfied, or a situation in which even a lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied.

26. A method according to any one of claims 18 to 25, wherein notification of the reason, cause or factor is taken into account by the core network to determine an updated QoS profile for the packet flow.

27. A method according to any one of claims 18 to 26, wherein notification of the reason, cause or factor causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow.

28. The method of any one of claims 18 to 27, further comprising, upon sending notification to the core network that the QoS profile is no longer satisfied, further indicating to the core network preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

29. The method of claim 28, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

30. The method of claim 28 or 29, further comprising generating a notification indicating a preferred value for the one or more QoS parameters based on artificial intelligence or machine learning based inference results received from a Radio Access Network (RAN) Intelligent Controller (RIC).

31. A method according to any one of claims 28 to 30, wherein the indication of the preferred values ​​of the one or more QoS parameters is taken into account by the core network to determine an updated QoS profile for the packet flow.

32. A method according to any one of claims 28 to 31, wherein the signalling of the preferred values ​​of the one or more QoS parameters causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow.

33. The method of any one of claims 18 to 32, wherein the packet flow is a Quality of Service (QoS) flow contained in a protocol data unit (PDU) session.

34. The method of any one of claims 18 to 33, wherein the QoS profile includes QoS parameters including 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

35. A program for causing a computer to perform a method for a radio access network node comprising: receiving from a core network a Quality of Service (QoS) profile for a packet flow; and, when sending a notification to the core network that the QoS profile is no longer met or that the QoS profile will be met again while maintaining the packet flow without releasing the packet flow or rejecting the setup or modification of the packet flow, also informing the core network of reasons, causes or factors that led to a determination that the QoS profile is no longer met or that the QoS profile will be met again.

36. The program product of claim 35, wherein the informing includes using a PDU SESSION RESOURCE NOTIFY message to indicate the reason, cause, or factor to the core network.

37. The program of claim 36, wherein the notifying includes setting a value indicating the reason, cause, or factor in a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

38. The program of claim 36, wherein the notifying includes setting a value indicating the reason, cause, or factor in a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

39. The program of claim 35, wherein the informing includes using an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate the reason, cause, or factor to the core network.

40. The program of any one of claims 35 to 39, wherein the reasons, causes, or factors include reasons, causes, or factors based on measurements of queuing delay or system load.

41. The program of any one of claims 35 to 39, wherein the reason, cause, or factor includes a reason, cause, or factor due to a radio link failure, due to radio access network internal congestion, or due to an inference result of artificial intelligence or machine learning.

42. The program of any one of claims 35 to 41, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network is satisfied, or a situation in which even a lowest priority alternative QoS profile among the one or more alternative QoS profiles cannot be satisfied.

43. The program of any one of claims 35 to 42, wherein notification of the reason, cause, or factor is taken into account by the core network to determine an updated QoS profile for the packet flow.

44. The program of any one of claims 35 to 43, wherein notification of the reason, cause, or factor causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow.

45. The program of any one of claims 35 to 44, wherein the method further comprises, upon sending a notification to the core network that the QoS profile is no longer satisfied, further indicating to the core network preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

46. ​​The program of claim 45, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

47. The program of claim 45 or 46, wherein the method further comprises generating a notification indicating a preferred value for the one or more QoS parameters based on results of artificial intelligence or machine learning based inference received from a Radio Access Network (RAN) Intelligent Controller (RIC).

48. The program of any one of claims 45 to 47, wherein the indication of the preferred values ​​of the one or more QoS parameters is taken into account by the core network to determine an updated QoS profile for the packet flow.

49. The program of any one of claims 45 to 48, wherein the notification of the preferred values ​​of the one or more QoS parameters causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow.

50. The program of any one of claims 35 to 49, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session.

51. The program of any one of claims 35 to 49, wherein the QoS profile includes QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

52. A core network node comprising: means for sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and means for receiving from the radio access network node a first indication that the packet flow is not released or the set-up or modification of the packet flow is not rejected and the packet flow is maintained but the QoS profile is no longer met or the QoS profile will be met again, together with a second indication of reasons, causes or factors that led to the determination that the QoS profile is no longer met or will be met again.

53. A core network node according to claim 52, wherein said receiving means is adapted to receive a PDU SESSION RESOURCE NOTIFY message containing said first and second notifications.

54. The core network node according to claim 53, wherein the first and second notifications are both indicated by a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

55. The core network node according to claim 53, wherein the second notification is indicated by a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

56. A core network node according to claim 52, wherein the receiving means is adapted to receive an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message containing the first and second indications.

57. A core network node according to claim 52, wherein the means for receiving is adapted to receive the first and second notifications via one or more other core network nodes.

58. A core network node according to any one of claims 52 to 57, wherein the reasons, causes or factors include reasons, causes or factors according to measurements of queuing delay or system load.

59. A core network node as claimed in any one of claims 52 to 57, wherein the reasons, causes or factors include reasons, causes or factors due to radio link failure, due to radio access network internal congestion, or due to artificial intelligence or machine learning inference results.

60. A core network node according to any one of claims 52 to 59, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network node is satisfied, or a situation in which even the lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied.

61. A core network node according to any one of claims 52 to 60, further comprising means for taking said indication of reason, cause or factor into account for determining an updated QoS profile for said packet flow.

62. A core network node according to claim 61, further comprising: means for informing said radio access network node of said updated QoS profile.

63. A core network node according to any one of claims 52 to 62, wherein the receiving means is adapted to receive from the radio access network node, together with the first and second notifications, a third notification indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

64. The core network node of claim 63, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

65. A core network node according to claim 63 or 64, further comprising means for taking into account preferred values ​​of said one or more QoS parameters for determining an updated QoS profile for said packet flow.

66. The core network node of claim 65, further comprising: means for informing the radio access network node of the updated QoS profile.

67. A core network node according to any one of claims 52 to 66, wherein the packet flow is a Quality of Service (QoS) flow contained in a protocol data unit (PDU) session.

68. A core network node according to any one of claims 52 to 67, wherein the QoS profile encompasses QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

69. A method performed by a core network node comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving a first indication from the radio access network node that the packet flow is not released or the set-up or modification of the packet flow is not rejected and the packet flow is maintained but the QoS profile is no longer met or the QoS profile will be met again, together with a second indication of reasons, causes or factors that led to a determination that the QoS profile is no longer met or will be met again.

70. The method of claim 69, wherein said receiving includes receiving a PDU SESSION RESOURCE NOTIFY message containing the first and second notifications.

71. The method of claim 70, wherein the first and second notifications are both indicated by a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

72. The method of claim 70, wherein the second notification is indicated by a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

73. The method of claim 69, wherein said receiving includes receiving an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message containing the first and second notifications.

74. The method of claim 69, wherein said receiving includes receiving the first and second notifications via one or more other core network nodes.

75. A method according to any one of claims 69 to 74, wherein the reasons, causes or factors include reasons, causes or factors according to measurements of queuing delay or system load.

76. A method according to any one of claims 69 to 74, wherein the reasons, causes or factors include reasons, causes or factors due to radio link failure, due to radio access network internal congestion, or due to artificial intelligence or machine learning inference results.

77. A method according to any one of claims 69 to 76, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network node are satisfied, or a situation in which even a lowest priority alternative QoS profile of the one or more alternative QoS profiles cannot be satisfied.

78. The method of any one of claims 69 to 77, further comprising taking the indication of the reason, cause, or factor into account for determining an updated QoS profile for the packet flow.

79. The method of claim 78, further comprising informing the radio access network node of the updated QoS profile.

80. A method according to any one of claims 69 to 79, wherein said receiving comprises receiving, together with the first and second notifications, a third notification from the radio access network node indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

81. The method of claim 80, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

82. The method of claim 80 or 81, further comprising taking into account the preferred values ​​of the one or more QoS parameters to determine an updated QoS profile for the packet flow.

83. The method of claim 82, further comprising informing the radio access network node of the updated QoS profile.

84. The method of any one of claims 69 to 83, wherein the packet flow is a Quality of Service (QoS) flow contained in a protocol data unit (PDU) session.

85. The method of any one of claims 69 to 84, wherein the QoS profile includes QoS parameters including 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

86. A program for causing a computer to perform a method for a core network node comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving a first notification from the radio access network node that the packet flow is not released or the setup or modification of the packet flow is not rejected and the packet flow is maintained but the QoS profile is no longer met or the QoS profile will be met again, together with a second notification of reasons, causes, or factors that led to a determination that the QoS profile is no longer met or will be met again.

87. The program product of claim 86, wherein said receiving includes receiving a PDU SESSION RESOURCE NOTIFY message containing the first and second notifications.

88. The program of claim 87, wherein the first and second notifications are both indicated by a Notification Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

89. The program of claim 87, wherein the second notification is indicated by a Cause information element in a QoS Flow Notify List information element in a PDU Session Resource Notify Transfer information element in the PDU SESSION RESOURCE NOTIFY message.

90. The program product of claim 86, wherein said receiving includes receiving an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message, or a PDU SESSION RESOURCE MODIFY RESPONSE message containing the first and second notifications.

91. The program product of claim 86, wherein said receiving includes receiving the first and second notifications via one or more other core network nodes.

92. The program of any one of claims 86 to 91, wherein the reasons, causes, or factors include reasons, causes, or factors based on measurements of queuing delay or system load.

93. The program of any one of claims 86 to 91, wherein the reason, cause, or factor includes a reason, cause, or factor due to a radio link failure, due to radio access network internal congestion, or due to an inference result of artificial intelligence or machine learning.

94. A program as claimed in any one of claims 86 to 93, wherein the situation in which the QoS profile is no longer satisfied includes a situation in which any of one or more alternative QoS profiles provided by the core network node is satisfied, or a situation in which even a lowest priority alternative QoS profile among the one or more alternative QoS profiles cannot be satisfied.

95. The program of any one of claims 86 to 94, wherein the method further comprises taking into account notification of the reason, cause, or factor to determine an updated QoS profile for the packet flow.

96. The program product of claim 95, wherein the method further comprises informing the radio access network node of the updated QoS profile.

97. The program of any one of claims 86 to 96, wherein said receiving comprises receiving, together with the first and second notifications, a third notification from the radio access network node indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

98. The program of claim 97, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

99. The program of claim 97 or 98, wherein the method further comprises taking into account the preferred values ​​of the one or more QoS parameters to determine an updated QoS profile for the packet flow.

100. The program product of claim 99, wherein the method further comprises informing the radio access network node of the updated QoS profile.

101. The program of any one of claims 86 to 100, wherein the packet flow is a Quality of Service (QoS) flow included in a protocol data unit (PDU) session.

102. The program of any one of claims 86 to 101, wherein the QoS profile includes QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

103. A radio access network node comprising: means for receiving from a core network a Quality of Service (QoS) profile for a packet flow; and means for informing the core network of preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow when sending an indication to the core network that the QoS profile is no longer met or that the QoS profile will be met again while maintaining the packet flow.

104. A radio access network node according to claim 103, wherein the one or more QoS parameters comprise at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

105. A radio access network node according to claim 103 or 104, further comprising means for generating a notification indicating a preferred value of the one or more QoS parameters based on results of artificial intelligence or machine learning based inference received from a Radio Access Network (RAN) Intelligent Controller (RIC).

106. A radio access network node according to any one of claims 103 to 105, wherein the indication of preferred values ​​of the preferred one or more QoS parameters is taken into account by the core network for determining an updated QoS profile for the packet flow.

107. A radio access network node according to any one of claims 103 to 106, wherein notification of the preferred values ​​of the preferred one or more QoS parameters causes the core network to determine and inform the radio access network node of an updated QoS profile for the packet flow.

108. A radio access network node according to any of claims 104 to 107, wherein the signalling means is adapted to use a PDU SESSION RESOURCE NOTIFY message to indicate preferred values ​​of the one or more QoS parameters to the core network.

109. A radio access network node according to any of claims 103 to 108, wherein the signalling means is adapted to use an INITIAL CONTEXT SETUP RESPONSE message, a PDU SESSION RESOURCE SETUP RESPONSE message or a PDU SESSION RESOURCE MODIFY RESPONSE message to indicate preferred values ​​of the one or more QoS parameters to the core network.

110. A radio access network node according to any one of claims 103 to 109, wherein the packet flow is a Quality of Service (QoS) flow contained in a protocol data unit (PDU) session.

111. A radio access network node according to any one of claims 103 to 110, wherein the QoS profile encompasses QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

112. A method performed by a radio access network node comprising: receiving from a core network a Quality of Service (QoS) profile for a packet flow; and, when sending an indication to the core network that the QoS profile is no longer met or that the QoS profile will be met again while maintaining the packet flow, also informing the core network of preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

113. A program for causing a computer to perform a method for a radio access network node comprising: receiving from a core network a Quality of Service (QoS) profile for a packet flow; and, when sending a notification to the core network that the QoS profile is no longer met or that the QoS profile will again be met while maintaining the packet flow, also informing the core network of preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

114. A core network node comprising: means for sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and means for receiving a first indication from the radio access network node that the packet flow is maintained but the QoS profile is no longer met or that the QoS profile will be met again, together with a second indication indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

115. The core network node of claim 114, wherein the one or more QoS parameters include at least one of a Guaranteed Flow Bit Rate (GBFR), a 5G QoS Identifier (5QI), a Packet Delay Budget (PDB), or a Packet Error Rate (PER).

116. A core network node according to claim 114 or 115, further comprising means for taking into account the preferred values ​​of the one or more QoS parameters for determining an updated QoS profile for the packet flow.

117. The core network node of claim 116, further comprising: means for informing the radio access network node of the updated QoS profile.

118. A core network node according to any one of claims 114 to 117, wherein the packet flow is a Quality of Service (QoS) flow contained in a protocol data unit (PDU) session.

119. A core network node according to any one of claims 114 to 118, wherein the QoS profile encompasses QoS parameters including a 5G QoS Identifier (5QI), Allocation and Retention Priority (ARP), and Guaranteed Flow Bit Rate (GBFR).

120. A method performed by a core network node comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving a first indication from the radio access network node that the packet flow is maintained but the QoS profile is no longer met or that the QoS profile will be met again, together with a second indication indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

121. A program for causing a computer to perform a method for a core network node comprising: sending a Quality of Service (QoS) profile for a packet flow to a radio access network node; and receiving a first notification from the radio access network node that the packet flow is maintained but the QoS profile is no longer met or that the QoS profile will again be met, together with a second notification indicating preferred values ​​for the radio access network node of one or more QoS parameters for the packet flow.

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