Radio access network node, core network node, communication node, and methods therefor

Abstract

This radio access network node is configured to receive a control message from a core network or another radio access network node, the control message including one or more information elements indicating a plurality of Quality of Service (QoS) flows to be handled in association with each other in packet forwarding by the radio access network node. This helps to provide improvements relating to support of handling of a plurality of QoS flows having multi-modal interdependencies, for example.

Description

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

[0001] The present disclosure relates to wireless communication networks, and more particularly to signaling between communication nodes associated with multiple flows.

[0002] The 3rd Generation Partnership Project (3GPP®) Release 18 supports 5th Generation (5G) New Radio (NR) enhancements for eXtended Reality (XR) services (see, for example, Sections 5.7.1, 5.7.7, and 5.37 of 3GPP NR1). These enhancements for XR include Protocol Data Unit (PDU) set-based Quality of Service (QoS) handling (see, for example, Section 5.37.5 of 3GPP NR1 and NR2). A PDU set is one or more PDUs that carry the payload of one unit of information (e.g., frame(s) or video slice(s) of an XR service) generated at the application level. All PDUs in a PDU set are transmitted within the same QoS flow.

[0003] 3GPP has started to consider further enhancements for XR services for 3GPP Release 19 and beyond (see, for example, Non-Patent Documents 5-7). One of the objectives of this work item is to efficiently and effectively support XR applications with multiple QoS flows with multi-modal inter-dependencies and to achieve multi-modal QoS requirements, such as synchronization and / or coordination (see, for example, Non-Patent Document 7).

[0004] Section 3.1 of Non-Patent Document 5 and Section 3.1 of Non-Patent Document 6 provide definitions of the term "multimodal data." According to these, multimodal data is defined to describe input data from different types of devices or sensors, or output data to different types of destinations (e.g., one or more User Equipments (UEs)), required for the same task or application. Multimodal data consists of one or more single-modal data, with strong dependencies between each single-modal data. Single-modal data can be considered as one type of data.

[0005] Tactile and multi-modal communication services combine ultra-low latency with extremely high availability, reliability, and security, enabling multi-modal interaction. The tactile Internet can be applied in a variety of fields, including industry, robotics and telepresence, virtual reality, augmented reality, healthcare, road traffic, serious gaming, education and culture, smart grid, etc.

[0006] Multiple modalities, when used in combination in a service, may convey redundant information, but may provide complementary ways of conveying information more effectively. The benefits of combining input from multiple sources and / or output to multiple destinations may result in more accurate and faster interpretations, faster responses, and a smoother and more natural communication experience.

[0007] In a multimodal interactive system, multimodal output is generated based on input from multiple sources. In a multimodal interactive system, modality refers to the type or representation of information in a particular interactive system. Multimodal interaction is the process of exchanging information across multiple modalities. Modal types include motion, sentiment, gesture, etc. Modal representations include video, audio, tactile (vibrations or other movements that provide haptic or tactile feelings to a person), etc.

[0008] Non-Patent Document 6 discloses signaling useful for supporting coordinated handling of multiple QoS flows with multimodal interdependencies, for example, in sections 6.1, 6.36, 6.38, 6.39, 6.40, 6.62, 6.63, 6.65, and 6.66. Section 6.66 of Non-Patent Document 6 describes a PDU session establishment procedure for multi-modality communication for a single UE situation. In this procedure, an Application Function (AF) assigns AF-specific service flow group IDs to XR application clients as pre-configuration. Multi-modality QoS policy information for paired service flows (or AF-specific service flow group IDs) is stored or provisioned in the Policy Control Function (PCF) (or Unified Data Repository (UDR)) for each UE.

[0009] If dynamic Policy and Charging Control (PCC) is applied, the PCC rules including the multi-modality QoS policy information of the paired service flows (or AF specific service flow group IDs) are provided to the Session Management Function (SMF). Otherwise, the SMF can apply local policies for the multi-modality QoS policy information, which is delivered to the UE. The multi-modality QoS policy information includes a required threshold of delay difference between the paired service flows (or AF specific service flow group IDs).

[0010] The SMF can send N4 session establishment or modification requests to the User Plane Function (UPF) to fulfill multi-modality QoS requirements (e.g., AF-specific service flow group ID). The SMF provides N2 Session Management (SM) information to the Next Generation Radio Access Network (NG-RAN) to fulfill multi-modality QoS requirements (e.g., AF-specific service flow group ID). The NG-RAN and UPF schedule packet delivery to ensure that the differential delay between paired QoS Flow Identifiers (QFIs) is not exceeded, but this is up to implementation.

[0011] 3GPP TS 23.501 V18.4.0 (2023-12)3GPP TS 38.413 V18.0.0 (2023-12)3GPP TS 38.423 V18.0.0 (2023-12)3GPP TS 38.415 V18.0.0 (2023-12)3GPP TR 22.847 V18.2.0 (2022-03)3GPP TR 23.700-60 V18.0.0 (2022-12)MediaTek, "New WID: XR (eXtended Reality) for NR Phase 3", RP-234057, 3GPP TSG RAN Meeting #102, Edinburgh, Scotland, December 11-15, 2023

[0012] The inventors have investigated and identified various challenges related to the coordinated handling of multiple QoS flows with multimodal interdependencies. Some of these challenges relate to signaling between a RAN node and a core network, between RAN nodes, or within a RAN node to support the handling of multiple QoS flows with multimodal interdependencies. It is not fully clear what signaling is needed between a RAN node and a core network, between RAN nodes, or within a RAN node to enable or facilitate the support of the handling of multiple QoS flows with multimodal interdependencies.

[0013] As mentioned above, Section 6.66 of NRTL 6 discloses a PDU session establishment procedure for multi-modality communication in a single UE scenario, which includes signaling between the SMF and the NG-RAN via the Access and Mobility Management Function (AMF). However, NRTL 6 does not explicitly describe the details of signaling between the SMF (or AMF) and the NG-RAN node. Furthermore, NRTL 6 does not disclose signaling between RAN nodes (e.g., between gNBs) to support handling of multiple QoS flows with multimodal interdependencies. NRTL 6 also does not disclose signaling within a RAN node to support handling of multiple QoS flows with multimodal interdependencies. Signaling within a RAN node includes, for example, signaling between the gNB Central Unit User Plane (CU-UP) and the gNB Distributed Unit (DU).

[0014] Some other challenges relate to admission control of multiple QoS flows by a RAN node. For example, in response to a request from the core network or another RAN node to set up, add, or modify multiple QoS flows, the RAN node determines whether to accept or admit the set up, add, or modify of these multiple QoS flows. However, if these multiple QoS flows have multimodal interdependencies, the RAN node may need to take special care in admission control of these multiple QoS flows.

[0015] 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 solving at least one of the multiple problems related to supporting the handling of multiple QoS flows having multimodal interdependencies, including the above-mentioned problem. It should be noted that this objective is only one of the multiple objectives to be achieved by the multiple embodiments disclosed in this specification. Other objectives or objectives and novel features will become apparent from the description of this specification or the accompanying drawings.

[0016] A first aspect is directed to a Radio Access Network (RAN) node configured to receive a control message from a core network or another RAN node, the control message including one or more information elements indicating a plurality of QoS flows to be treated in association with one another in packet forwarding by the RAN node.

[0017] A second aspect is directed to a method performed by a RAN node, the method comprising receiving a control message from a core network or another RAN node, the control message including one or more information elements indicating a plurality of QoS flows to be treated in relation to one another in packet forwarding by the RAN node.

[0018] A third aspect is directed to a core network node configured to send a control message to a RAN node, the control message including one or more information elements indicating a plurality of QoS flows to be treated in association with each other in packet forwarding by the RAN node.

[0019] A fourth aspect is directed to a method performed by a core network node, the method comprising sending a control message to a RAN node, the control message including one or more information elements indicating a plurality of QoS flows to be treated in relation to one another in packet forwarding by the RAN node.

[0020] A fifth aspect is directed to a RAN node (first RAN node) configured to send a control message to a second RAN node, the control message including one or more information elements indicating a plurality of QoS flows to be treated in association with each other in packet forwarding by the second RAN node.

[0021] A sixth aspect is directed to a method performed by a RAN node (first RAN node), the method comprising sending a control message to a second RAN node, the control message including one or more information elements indicating a plurality of QoS flows to be treated in association with each other in packet forwarding by the second RAN node.

[0022] A seventh aspect is directed to a RAN node configured to send a control message to a core network or another RAN node, the control message including an information element indicating whether the RAN node supports a function for jointly handling multiple interdependent QoS flows.

[0023] An eighth aspect is directed to a method performed by a RAN node, the method comprising sending a control message to a core network or another RAN node, the control message including an information element indicating whether the RAN node supports the capability to jointly handle multiple interdependent QoS flows.

[0024] A ninth aspect is directed to a core network node configured to receive a control message from a RAN node, the control message including an information element indicating whether the RAN node supports a function for jointly handling multiple interdependent QoS flows.

[0025] A tenth aspect is directed to a method performed by a core network node, the method comprising receiving a control message from a RAN node, the control message including an information element indicating whether the RAN node supports the capability to jointly handle multiple interdependent QoS flows.

[0026] An eleventh aspect is directed to a RAN node (first RAN node), configured to receive a control message from a second RAN node, the control message including an information element indicating whether a function for jointly handling multiple interdependent QoS flows is supported by the second RAN node.

[0027] A twelfth aspect is directed to a method performed by a RAN node (first RAN node), the method comprising receiving a control message from a second RAN node, the control message including an information element indicating whether the second RAN node supports a function for jointly handling multiple interdependent QoS flows.

[0028] A thirteenth aspect is directed to a RAN node configured to receive a request for the setup, addition, or modification of a first QoS flow from a core network or another RAN node, and to determine whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the RAN node.

[0029] A fourteenth aspect is directed to a method performed by a RAN node, the method including: (a) receiving a request from a core network or another RAN node to set up, add, or modify a first QoS flow; and (b) determining whether to accept the set up, add, or modify the first QoS flow depending on whether to accept the set up, add, or modify one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the RAN node.

[0030] A fifteenth aspect is directed to a communications node (a first communications node, e.g., a core network node, a RAN node, or a CU-UP), configured to, when forwarding packets of a first QoS flow to a second communications node, provide to the second communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

[0031] A sixteenth aspect is directed to a method performed by a communications node (a first communications node, e.g., a core network node or a RAN node), the method including, when forwarding packets of a first QoS flow to a second communications node, providing to the second communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

[0032] A seventeenth aspect is directed to a communications node (a second communications node, e.g., a RAN node or a DU), configured to, upon receiving packets of a first QoS flow from a first communications node, receive from the first communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

[0033] An eighteenth aspect is directed to a method performed by a communications node (a second communications node, e.g., a RAN node or a DU), the method including, upon receiving packets of a first QoS flow from a first communications node, receiving from the first communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

[0034] A nineteenth aspect is directed to a program, the program including a group of instructions (software code) that, when loaded into a computer, causes the computer to perform a method according to any one of the above aspects.

[0035] According to the above-described aspects, it is possible to provide an apparatus, a method, and a program that contribute to solving at least one of multiple problems related to supporting the handling of multiple QoS flows with multimodal interdependencies, including the problems described above.

[0036] FIG. 1 illustrates an example configuration of a wireless communication system according to one or more embodiments. FIG. 2 illustrates an example configuration of a wireless communication system according to one or more embodiments. FIG. 3 illustrates an example user plane protocol stack according to one or more embodiments. FIG. 4 illustrates a sequence diagram of example signaling according to one or more embodiments. FIG. 5 illustrates a sequence diagram of example signaling according to one or more embodiments. FIG. 6 illustrates an example format of a QoS Flow Level QoS Parameters information element according to one or more embodiments. FIG. 7 illustrates an example format of a Multi-modality Parameters information element according to one or more embodiments. FIG. 8 illustrates an example format of a Multi-modality Parameters information element according to one or more embodiments. FIG. 9 illustrates an example format of a Multi-modality Parameters information element according to one or more embodiments. FIG. 10 illustrates an example sequence diagram of example signaling according to one or more embodiments. FIG. 11 illustrates an example format of a PDU Session Resource Setup Response Transfer information element according to one or more embodiments. FIG. 12 illustrates an example format of a Dependency QoS Flows Handling Together Indicator information element according to one or more embodiments. FIG. 13 illustrates an example sequence diagram of example signaling according to one or more embodiments. Figure 1 is a sequence diagram illustrating example signaling according to one or more embodiments;Figure 2 is a sequence diagram illustrating example signaling according to one or more embodiments;Figure 3 is a diagram illustrating an example format of an Extended DL PDU Session Information frame according to one or more embodiments;Figure 4 is a diagram illustrating an example format of an Extended DL PDU Session Information frame according to one or more embodiments;1A-1C are a flowchart illustrating an example of the operation of a RAN node in accordance with one or more embodiments, a block diagram illustrating an example configuration of a UE in accordance with one or more embodiments, a block diagram illustrating an example configuration of a RAN node in accordance with one or more embodiments, and a block diagram illustrating an example configuration of a core network node in accordance with one or more embodiments.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The following embodiments are described primarily for the 3GPP 5th generation mobile communication system (5G system), but may also be applied to other wireless communication systems that support handling of multiple QoS flows (or packet flows) with multimodal interdependencies.

[0041] 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.

[0042] First, the configurations and operations of multiple network elements common to multiple embodiments will be described. Figure 1 shows an example configuration of a wireless communication system according to multiple embodiments. Each of the elements shown in Figure 1 is a network function, and provides an interface defined by, for example, 3GPP. 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.

[0043] 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).

[0044] 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. The 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). The NG-RAN 2 includes one or more RAN nodes 3. The 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 the 5GC 4, including an AMF 5, an SMF 6, and a UPF 7. The UPF 7 may include multiple interconnected UPFs. More specifically, the UPF 7 includes a PDU Session Anchor (PSA) UPF and may include one or more intermediate UPFs. The intermediate UPFs may provide an Uplink Classifier (UL CL) or Branching Point (BP) function.

[0045] UE1 uses 5G connectivity services provided by NG-RAN2 and 5GC4 to communicate with Data Network (DN) 8. More specifically, UE1 is connected to RAN node 3 in NG-RAN2 and communicates with DN8 via UPF 7 in 5GC4. UE1 establishes one or more Protocol Data Unit (PDU) sessions 100 between UE1 and UPF 7 (i.e., PSA UPF) to which UE1 and DN8 are connected. The PDU session 100 is an association, session, or connection between UE1 and DN8. The PDU session 100 is used to provide PDU connectivity services (i.e., exchange of PDUs between UE1 and DN8). 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, the UE 1 may establish multiple PDU sessions with multiple PDU session anchors (UPFs) 7, respectively, to access multiple DNs 8 concurrently.

[0046] 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.

[0047] 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 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 7.

[0048] As shown in FIG. 1 , multiple QoS flows 120 associated with different QoS requirements can be established for one PDU session 100. One or more applications 10 in a UE 1 transmit or receive multiple packet flows to or from one or more applications 80 in a DN 8 via the multiple QoS flows 120. For example, an application 80 or one or more application servers in a DN 8 may provide an XR service to a UE 1 via a 5GC 4 and an NG-RAN 2. The DN 8 may be an Edge Data Network (EDN) or a Local Area Data Network (LADN). One or more application servers in the DN 8 may include one or more edge computing servers located near the NG-RAN 2. In other words, the application 80 in the DN 8 may be hosted on one or more edge computing servers located near the NG-RAN 2.

[0049] 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 DN8. 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 DN8.

[0050] The RAN node 3 provides one or more cells. The UE 1 may be simultaneously connected to multiple cells provided by the RAN node 3. In other words, the UE 1 may perform carrier aggregation (CA) between multiple cells provided by the RAN node 3. In addition, the UE 1 may be simultaneously connected to the 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).

[0051] The RAN node 3 may be a gNB or an ng-eNB, which 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.

[0052] The 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 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. The DU may host the high PHY layer, and the low PHY layer may be located in one or more Transmission-Reception Points (TRPs) connected to the gNB-DU. A TRP may also be called a Radio Unit (RU) or Remote Radio Head (RRH).

[0053] The CU-CP may be a logical node that hosts the control plane functions of the CU, e.g., the control plane parts of the RRC and PDCP protocols of the gNB-CU. The CU-UP may be a logical node that hosts the user plane functions of the CU, e.g., the user plane parts of the PDCP protocol and the SDAP protocol of the gNB-CU.

[0054] FIG. 2 shows a configuration example in which the RAN node 3 is a gNB. In the example of FIG. 2, the gNB-CU 30 includes a gNB-CU-CP 31 and one or more gNB-CU UPs 32. The gNB-CU-CP 31 is a logical node that hosts the control plane portion of the gNB-CU 30's RRC and PDCP protocols. The gNB-CU-CP 31 terminates an E1 interface connected to each gNB-CU-UP 32 and an F1-C interface connected to each of one or more gNB-DUs 35. The E1 interface uses the E1 Application Protocol (E1AP). The F1-C interface also uses the F1 Application Protocol (F1AP). In addition, the gNB-CU-CP 31 terminates an NG-C interface connected to a control plane node (i.e., AMF 5) in the core network. The NG-C interface may also be referred to as an N2 interface. The NG-C interface uses the NG Application Protocol (NGAP).

[0055] The gNB-CU-UP 32 is a logical node that hosts the user plane portion of the PDCP protocol of the gNB-CU 30 for the en-gNB, or the user plane portion of the PDCP protocol and the SDAP protocol of the gNB-CU 30 for the gNB. The gNB-CU-UP 32 terminates the E1 interface connected to the gNB-CU-CP 31 and the F1-U interface connected to each of one or more gNB-DUs 35. The F1-U interface uses the General Packet Radio Service Tunneling Protocol User Plane (GTP-U) protocol. The GTP-U protocol uses GTP-U tunnels to carry encapsulated user data packets (i.e., T-PDUs) and signaling messages. In addition, the gNB-CU-UP 32 terminates the NG-U interface connected to a user plane node (i.e., UPF7) in the core network. The NG-U interface may also be referred to as the N3 interface. The NG-U interface uses the GTP-U protocol.

[0056] Returning to FIG. 1 , the description continues. The AMF 5 is one of the network functions in the 5G control plane. The AMF 5 provides the termination of the RAN Control Plane (CP) interface (i.e., the N2 interface). The AMF 5 terminates a single signaling connection (i.e., a Non-Access Stratum (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 with 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 a 5G system, mobility management can also be said to be included in registration management.

[0057] 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.

[0058] 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 a PDU session to provide a PDU connectivity service to the UE 1. The session management includes signaling between the UE 1, the NG-RAN 2, the AMF 5, and the UPF 7 for establishing, modifying, and releasing a PDU session.

[0059] 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 N2 SM information to and from the NG-RAN 2 (or RAN node 3) via the communication service provided by the AMF 5. The N2 SM 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) of one or more QoS flows, and QoS profiles.

[0060] 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.

[0061] Figure 3 shows an example of a user plane protocol stack provided by the wireless communication system of Figure 1. UE1 and DN8 (e.g., application server) can exchange PDUs (e.g., Internet Protocol (IP) packets) at the PDU layer. The application layer refers to a layer above the PDU layer. Therefore, if the PDU layer is the IP layer, the application layer may include transport layer protocols of the Open Systems Interconnection (OSI) model (e.g., Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)). For example, in the case of an XR service, the PDU layer protocol may be IP, while the application layer protocol may include H.264, H265, or H.266 codec, Real-time Transport Protocol (RTP), and UDP.

[0062] If the upper layer PDUs are XR service PDUs, they may be dependent on each other and have different levels of importance. For example, PDUs that depend on other PDUs are expected to be more important. For example, PDUs that depend on other PDUs may be PDUs carrying fragments of intra-coded (I) frames, and other PDUs may be PDUs carrying fragments of predicted (P) frames or bi-directional predicted (B) frames.

[0063] For example, consecutive PDUs with the same importance level (e.g., PDUs carrying fragments of an I-frame) can be treated as one PDU set. Alternatively, PDUs carrying a payload of one unit of information generated at the application level can be treated as one PDU set. Therefore, an XR service flow can be considered as a flow of consecutive PDU sets. In other words, XR service data can be categorized as a list of consecutive PDU sets. For example, one PDU set may correspond to PDUs carrying the data of one video frame. Except for the importance level, the Quality of Service (QoS) requirements of an XR service flow are consistent. Therefore, an XR service flow can be mapped to a QoS flow. In this case, one QoS flow contains multiple PDU sets with different importance levels. The importance level for each PDU set is defined or determined by the application 80 (e.g., an XR application, an Application Function (AF), or an application server) and provided to the 5GC 4 as part of the PDU set-related information.

[0064] A PDU set consists of one or more PDUs carrying a payload of one unit of information (e.g., a frame or video slice of an XR service) generated at the application level. In some implementations, all PDUs in a PDU set are required by the application layer to use the corresponding information unit. In other implementations, the application layer can recover all or part of the information unit even if some PDUs are missing. That is, multiple PDU sets can be classified into different types based not only on importance or dependency, but also on differences in encoding methods, for example.

[0065] For example, in a certain type of PDU set, all PDUs in the PDU set are required by the application layer to use the corresponding information unit, and for this type of PDU set, all PDUs in the PDU set are said to be essential PDUs.

[0066] In another type of PDU set, one or more specific PDUs in the PDU set are required by the application layer to use the corresponding information unit, but the remaining PDUs are not necessarily required by the application layer. In this type of PDU set, some PDUs, or a subset of PDUs, in the PDU set can be said to be essential PDUs.

[0067] For yet another type of PDU set, the application layer must receive at least K of the N PDUs in the entire PDU set in order to use the corresponding information unit. For this type of PDU set, no PDUs are essential, and the K parameter must be included in the PDU set related information.

[0068] As can be seen from the above description, a PDU set is based on the dependency of PDUs belonging to one QoS flow. That is, all PDUs in one PDU set are transmitted within the same QoS flow. Additionally or alternatively, if the upper layer PDUs are XR service PDUs, the UE 1, the NG-RAN 2, and the 5GC 4 may support forwarding of multiple QoS flows with multimodal interdependencies. The UE 1, the NG-RAN 2, and the 5GC 4 may operate to achieve multimodal QoS requirements, such as synchronization and / or coordination, for these multiple QoS flows. The UE 1, the NG-RAN 2, and the 5GC 4 may associate and handle multiple QoS flows with multimodal interdependencies to achieve the multimodal QoS requirements.

[0069] Multimodal data may be defined to describe input data from different types of devices or sensors, or output data to different types of destinations (e.g., one or more User Equipments (UEs)) required for the same task or application. Multimodal data is composed of one or more unimodal data, with strong dependencies between each unimodal data. Unimodal data can be considered as one type of data.

[0070] In a multimodal interactive system, multimodal output is generated based on input from multiple sources. In a multimodal interactive system, modality refers to the type or representation of information in a particular interactive system. Multimodal interaction is the process of exchanging information across multiple modalities. Modal types include motion, sentiment, gesture, etc. Modal representations include video, audio, tactile (vibrations or other movements that provide haptic or tactile feelings to a person), etc.

[0071] In one example, multiple QoS flows with multimodal interdependencies are associated with one another such that packets must be transmitted synchronously or within a predetermined time difference when transmitted over one or more data radio bearers (DRBs) from the NG-RAN 2 to the UE 1. The RAN node 3 may be operable to transmit data or packets of these multiple QoS flows synchronously or within a predetermined time difference when transmitted over one or more DRBs from the RAN node 3 to the UE 1. The predetermined time difference may be referred to as a required threshold of delay difference, a synchronization threshold, or a multimodal synchronization threshold. The multimodal synchronization threshold may be defined as the maximum tolerable temporal separation of the onsets of two stimuli, one of which is presented to one sense and the other to another sense, such that the accompanying sensory objects are perceived as being synchronous.

[0072] Additionally or alternatively, multiple QoS flows having multimodal interdependencies are associated with one another such that if a packet of a certain QoS flow is discarded at the NG-RAN 2 without being forwarded to the UE 1, then forwarding of one or more packets of the remaining one or more QoS flows is no longer required. The RAN node 3 may determine that if a packet of a certain QoS flow is discarded at the RAN node 3 without being forwarded to the UE 1, then forwarding of one or more packets of the remaining one or more QoS flows is no longer required.

[0073] Additionally or alternatively, multiple QoS flows having multimodal interdependencies may be associated with each other such that they need to be set up, added, or modified together. In other words, multiple QoS flows having multimodal interdependencies may be associated with each other such that if the set up, addition, or modification of one QoS flow is not accepted, the set up, addition, or modification of one or more of the remaining QoS flows is no longer required. When a RAN node 3 receives a request from a 5GC 4 (e.g., an AMF 5 or an SMF 6) or another NG-RAN node to set up, add, or modify multiple QoS flows, the RAN node 3 may determine that if the set up, addition, or modification of one QoS flow is not accepted, the set up, addition, or modification of one or more of the remaining QoS flows is no longer required.

[0074] The UE 1, NG-RAN 2, and 5GC 4 perform signaling and operations to enable or facilitate support of coordinated handling of multiple QoS flows with multimodal interdependencies, details of which are described in the following embodiments.

[0075] First Embodiment This embodiment provides an improvement for coordinated handling of multiple QoS flows with multimodal interdependence. Figure 4 shows an example of signaling between the AMF 5 or SMF 6 and the RAN node 3. In step 401, the AMF 5 sends a control message (i.e., an NGAP message) to the RAN node 3. The NGAP message includes one or more information elements (IEs) that indicate (or specify) multiple QoS flows that should be handled in association with each other in packet forwarding by the RAN node 3. In other words, the NGAP message includes one or more IEs that indicate (or specify) multiple QoS flows with multimodal interdependence.

[0076] The NGAP message of step 401 may request the RAN node 3 to set up, add or modify resources for multiple QoS flows. The NGAP message may be an INITIAL CONTEXT SETUP REQUEST, a PDU SESSION RESOURCE SETUP REQUEST, a PDU SESSION RESOURCE MODIFY REQUEST or a HANDOVER REQUEST message.

[0077] The one or more IEs included in the NGAP message in step 401 may be N2 SM IEs sent from the SMF 6 to the RAN node 3 via the AMF 5. That is, in step 401, the SMF 6 may send one or more IEs indicating multiple QoS flows to be handled in association with each other in packet forwarding by the RAN node 3 to the RAN node 3 via the AMF 5.

[0078] In one example, the one or more IEs may indicate a predetermined time difference within which packets of multiple QoS flows need to be transmitted. As mentioned above, the predetermined time difference may be referred to as a differential delay requirement threshold, a synchronization threshold, or a multimodal synchronization threshold.

[0079] Additionally or alternatively, the one or more IEs may specify one or more critical QoS flows among the multiple QoS flows. A critical QoS flow may be a QoS flow whose packets must be forwarded. The multiple QoS flows may be associated with each other such that if one or more packets of one or more critical QoS flows are discarded at the RAN node 3 rather than forwarded to the UE 1, the forwarding of one or more packets of the remaining one or more QoS flows is no longer required. Additionally or alternatively, the multiple QoS flows may be associated with each other such that if the setup, addition, or modification of any of the one or more critical QoS flows is not accepted, the setup, addition, or modification of the remaining one or more QoS flows is no longer required.

[0080] The one or more IEs may indicate (or specify) an association between an identifier (e.g., QFI) of a first QoS flow and one or more identifiers (e.g., QFIs) of one or more associated QoS flows to be handled in association with the first QoS flow. Additionally or alternatively, the one or more IEs may indicate an association between an identifier (e.g., QFI) of each of a plurality of QoS flows and an identifier assigned to a QoS flow group corresponding to the plurality of QoS flows. The name of the identifier assigned to the QoS flow group may be, for example, but not limited to, a QoS flow group coordination identifier or ID (QFGCI).

[0081] The RAN node 3 may take into consideration the interdependencies of multiple QoS flows specified by one or more IEs received from the AMF 5 or SMF 6 in packet forwarding of these multiple QoS flows. The packet forwarding includes one or any combination of packet forwarding in a radio layer (e.g., DRBs), packet forwarding in an NG-U tunnel (GTP-U tunnel), and packet forwarding in an Xn-U tunnel (GTP-U tunnel).

[0082] Additionally or alternatively, the RAN node 3 may take into account interdependencies of multiple QoS flows specified by one or more received IEs in admission control of these multiple QoS flows. Considering the case where the multiple QoS flows include a first QoS flow and a second QoS flow, the RAN node 3 may decide whether to accept the setup, addition or modification of the first QoS flow depending on whether to accept the setup, addition or modification of the second QoS flow.

[0083] The operation of the RAN node 3 and the AMF 5 (and / or SMF 6) described with reference to Figure 4 can provide signaling details between the 5GC 4 and the NG-RAN 2 to support handling of multiple QoS flows with multimodal interdependencies. For example, when the 5GC 4 requests the RAN node 3 to set up, add, or modify resources (e.g., radio resources and / or NG-U resources) for multiple QoS flows, the 5GC 4 can inform the RAN node 3 that these multiple QoS flows have multimodal interdependencies.

[0084] 5 shows an example of signaling on a control plane interface (i.e., Xn Application Protocol (XnAP) interface) between two RAN nodes 3. In step 501, RAN node 3B sends a control message (i.e., XnAP message) to RAN node 3A. The XnAP message includes one or more IEs indicating (or specifying) multiple QoS flows that should be treated as associated with each other in packet forwarding by RAN node 3B. In other words, the XnAP message includes one or more IEs indicating (or specifying) multiple QoS flows that have multimodal interdependencies.

[0085] The XnAP message in step 501 may request the RAN node 3A to set up resources (e.g., radio resources, NG-U resources, and / or Xn-U resources) for multiple QoS flows during handover of the UE 1 from the RAN node 3B to the RAN node 3A. The RAN node 3A may be the target node of the handover, and the RAN node 3B may be the source node of the handover. This handover may be a conditional handover. That is, during the (conditional) handover procedure of the UE 1, the source node (RAN node 3B) may indicate (or specify) multiple QoS flows with multimodal interdependencies to the target node (RAN node 3A). In other words, the source node may indicate (or specify) multiple QoS flows to be treated as associated with each other when the target node forwards packets.

[0086] In a handover (or conditional handover) procedure, the XnAP message of step 501 may be a HANDOVER REQUEST message. The HANDOVER REQUEST message includes a PDU Session Resources To Be Setup List IE. One or more of the above-mentioned IEs may be included in a QoS Flow Level QoS Parameters IE included in the PDU Session Resources To Be Setup List IE.

[0087] The XnAP message in step 501 may request or authorize the RAN node 3A to set up, add, or modify resources (e.g., radio resources, NG-U resources, and / or Xn-U resources) for multiple QoS flows in a dual connectivity-related procedure. In one example, the RAN node 3A may be a secondary node (SN) in dual connectivity, and the RAN node 3B may be a master node (MN) in dual connectivity. That is, in a dual connectivity-related procedure, the MN may indicate (or specify) multiple QoS flows having multimodal interdependencies to the SN. In other words, the MN may indicate (or specify) multiple QoS flows to be treated as associated with each other in packet forwarding by the SN. The dual connectivity-related procedure may be a secondary node addition procedure or a secondary node modification procedure. The dual connectivity related procedure may be a conditional Primary Secondary Cell Group (SCG) Cell (PSCell) addition procedure or a conditional PSCell modification procedure.

[0088] The XnAP message may be an S-NODE ADDITION REQUEST or an S-NODE MODIFICATION REQUEST message. The S-NODE ADDITION REQUEST message may include one or both of a PDU Session Resource Setup Info - SN terminated IE and a PDU Session Resource Setup Info - MN terminated IE. The S-NODE MODIFICATION REQUEST message may include one or any combination of a PDU Session Resource Setup Info - SN terminated IE, a PDU Session Resource Setup Info - MN terminated IE, a PDU Session Resource Modification Info - SN terminated, and a PDU Session Resource Modification Info - MN terminated. One or more of the above IEs may be included in a QoS Flow Level QoS Parameters IE contained in the PDU Session Resource Setup Info - SN terminated, PDU Session Resource Setup Info - MN terminated, PDU Session Resource Modification Info - SN terminated, or PDU Session Resource Modification Info - MN terminated IE.

[0089] In another example, the RAN node 3A may be a dual connectivity MN, and the RAN node 3B may be a dual connectivity SN. That is, in a dual connectivity related procedure, the SN may indicate (or specify) to the MN multiple QoS flows having multimodal interdependencies. In other words, the SN may indicate (or specify) to the MN multiple QoS flows to be handled in association with each other in packet forwarding by the MN. The dual connectivity related procedure may be a secondary node addition procedure or a secondary node modification procedure. The dual connectivity related procedure may be a conditional PSCell addition procedure or a conditional PSCell change procedure.

[0090] The XnAP message may be an S-NODE ADDITION REQUEST ACKNOWLEDGE, an S-NODE MODIFICATION REQUEST ACKNOWLEDGE, or an S-NODE MODIFICATION REQUIRED message. The S-NODE ADDITION REQUEST ACKNOWLEDGE message may include a PDU Session Resource Setup Response Info - SN terminated IE. The S-NODE MODIFICATION REQUEST ACKNOWLEDGE message may include one or both of a PDU Session Resource Setup Response Info - SN terminated IE and a PDU Session Resource Modification Response Info - SN terminated IE. The S-NODE MODIFICATION REQUIRED message may include a PDU Session Resource Modification Required Info - SN terminated IE. One or more of the above IEs may be included in a QoS Flow Level QoS Parameters IE contained in a PDU Session Resource Setup Response Info - SN terminated, a PDU Session Resource Modification Response Info - SN terminated, or a PDU Session Resource Modification Required Info - SN terminated IE.

[0091] 4, in one example, the one or more IEs may indicate a predetermined time difference within which packets of the multiple QoS flows need to be transmitted. As mentioned above, the predetermined time difference may be referred to as a synchronization threshold or a multimodal synchronization threshold. Additionally or alternatively, the one or more IEs may specify one or more critical QoS flows among the multiple QoS flows.

[0092] 4, these one or more IEs may indicate (or specify) an association between an identifier (e.g., QFI) of a first QoS flow and one or more identifiers (e.g., QFIs) of one or more associated QoS flows to be treated in association with the first QoS flow. Additionally or alternatively, these one or more IEs may indicate an association between an identifier (e.g., QFI) of each of a plurality of QoS flows and an identifier assigned to a QoS flow group corresponding to the plurality of QoS flows. The name of the identifier assigned to the QoS flow group may be, for example, but not limited to, QFGCI.

[0093] The RAN node 3A may take into consideration the interdependence of multiple QoS flows specified by one or more IEs received from the RAN node 3B in forwarding packets of these multiple QoS flows, including one or any combination of packet forwarding in a radio layer (e.g., DRBs), packet forwarding in an NG-U tunnel (GTP-U tunnel), and packet forwarding in an Xn-U tunnel (GTP-U tunnel).

[0094] Additionally or alternatively, the RAN node 3A may take into account interdependencies of multiple QoS flows specified by one or more received IEs in admission control of these multiple QoS flows. Considering the case where the multiple QoS flows include a first QoS flow and a second QoS flow, the RAN node 3A may decide whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of the second QoS flow.

[0095] The operation of RAN nodes 3A and 3B described with reference to Figure 5 may provide signaling details between two RAN nodes 3 to support handling of multiple QoS flows with multimodal interdependencies. For example, when the RAN node 3B requests or authorizes the other RAN node 3A to set up, add, or modify resources (e.g., radio resources, NG-U resources, and / or Xn-U resources) for multiple QoS flows, the RAN node 3B may inform the RAN node 3A that these multiple QoS flows have multimodal interdependencies.

[0096] Figure 6 shows an example of the format of the QoS Flow Level QoS Parameters IE that can be transmitted via the NGAP message in step 401. The format of the QoS Flow Level QoS Parameters IE that can be transmitted via the XnAP message in step 501 may also be similar to that shown in Figure 6. In the example of Figure 6, the QoS Flow Level QoS Parameters IE may include a Multi-modality Parameters IE601.

[0097] FIG. 7 shows an example of the format of the Multi-modality Parameters IE 601. In the example of FIG. 7, the Multi-modality Parameters IE 601 may include one or both of a Dependency QoS flow Identifier IE 701 and a Delay Difference IE 702. The Dependency QoS flow Identifier IE 701 specifies the QFI of another QoS flow that has interdependency with the QoS flow with which the QoS Flow Level QoS Parameters IE is associated. The Multi-modality Parameters IE 601 may include a list of multiple Dependency QoS flow Identifier IEs 701 to specify two or more other QoS flows. The Delay Difference IE 702 specifies the differential delay requirement threshold, synchronization threshold, or multimodal synchronization threshold, as described above. To specify respective synchronization thresholds for two or more other QoS flows, the Multi-modality Parameters IE 601 may include a list of Delay Differences IEs 702.

[0098] FIG. 8 shows another example of the format of the Multi-modality Parameters IE 601. In the example of FIG. 8, the Multi-modality Parameters IE 601 may include one or both of a Dependency QoS flow Identifier IE 801 and a Handling Together Indication IE 802. The Dependency QoS flow Identifier IE 801 is similar to the Dependency QoS flow Identifier IE 701 in FIG. 7. Specifically, the Dependency QoS flow Identifier IE 801 specifies the QFI of another QoS flow that has interdependency with the QoS flow to which the QoS Flow Level QoS Parameters IE is associated. The Multi-modality Parameters IE 601 may include a list of multiple Dependency QoS flow Identifier IEs 801 to specify two or more other QoS flows. The Handling Together Indication IE 802 specifies whether the QoS flow to which the QoS Flow Level QoS Parameters IE is associated needs to be handled together with the other QoS flows specified in the Dependency QoS flow Identifier IE 801. The Handling Together Indication IE 802 is enumerated and may indicate "true" or "false." To specify respective handling for two or more other QoS flows, the Multi-modality Parameters IE 601 may include a list of Handling Together Indication IEs 802.

[0099] 9 shows yet another example of the format of the Multi-modality Parameters IE 601. In the example of FIG. 9, the Multi-modality Parameters IE 601 may include one or both of a QoS flow group coordination ID IE 901 and a Critical QoS flows in QoS flow group IE 902. The QoS flow group coordination ID IE 901 specifies the identifier (e.g., QoS flow group coordination ID) of the QoS flow group to which the QoS flow associated with the QoS Flow Level QoS Parameters IE belongs. The Critical QoS flows in QoS flow group IE 902 indicates whether the QoS flow associated with the QoS Flow Level QoS Parameters IE is a critical QoS flow in the QoS flow group. The Critical QoS flows in QoS flow group IE 902 is an enumerated type and may indicate "true" or "false."

[0100] Second Embodiment This embodiment provides an improvement for coordinated handling of multiple QoS flows with multimodal interdependencies. Figure 10 shows an example of signaling between the AMF 5 or SMF 6 and the RAN node 3. In step 1001, the RAN node 3 sends a control message (i.e., an NGAP message) to the AMF 5. The NGAP message includes an IE indicating whether the RAN node 3 supports the function of jointly handling multiple interdependent QoS flows. In other words, the IE indicates to the 5GC 4 whether the RAN node 3 supports handling of multiple QoS flows with multimodal interdependencies (or multiple QoS flow-based handling).

[0101] The above-mentioned IE included in the NGAP message in step 1001 may be an N2 SM IE sent from the RAN node 3 to the SMF 6 via the AMF 5. That is, in step 1001, the RAN node 3 may send an IE indicating whether or not the RAN node 3 supports a function for collectively handling multiple interdependent QoS flows to the SMF 6 via the AMF 5.

[0102] The NGAP message in step 1001 may be an INITIAL CONTEXT SETUP RESPONSE, PDU SESSION RESOURCE SETUP RESPONSE, PDU SESSION RESOURCE MODIFY RESPONSE, PATH SWITCH REQUEST, or HANDOVER REQUEST ACKNOWLEDGE message. The above IEs may be included in a PDU Session Resource Setup Response Transfer IE, a PDU Session Resource Modify Response Transfer IE, a Path Switch Request Transfer IE, or a Handover Request Acknowledge Transfer IE. The PDU Session Resource Setup Response Transfer IE can be included in a PDU SESSION RESOURCE SETUP RESPONSE message or an INITIAL CONTEXT SETUP RESPONSE message. The PDU Session Resource Modify Response Transfer IE can be included in a PDU SESSION RESOURCE MODIFY RESPONSE message. The Path Switch Request Transfer IE can be included in a PATH SWITCH REQUEST message. The Handover Request Acknowledge Transfer IE can be included in the HANDOVER REQUEST ACKNOWLEDGE message.

[0103] The operation of the RAN node 3 and the AMF 5 (and / or SMF 6) described with reference to Figure 10 can provide details of signaling between the 5GC 4 and the NG-RAN 2 for support of handling multiple QoS flows with multimodal interdependencies. Specifically, the RAN node 3 can inform the 5GC 4 whether the function of jointly handling multiple interdependent QoS flows is supported by the RAN node 3.

[0104] 11 shows an example of signaling on a control plane interface (i.e., XnAP interface) between two RAN nodes 3. In step 1101, RAN node 3A sends a control message (i.e., XnAP message) to RAN node 3B. The XnAP message includes an IE indicating whether the RAN node 3A supports the function of handling multiple interdependent QoS flows together. In other words, the IE indicates to RAN node 3B whether RAN node 3A supports the handling of multiple QoS flows with multimodal interdependencies (or multiple QoS flow-based handling).

[0105] The XnAP message in step 1101 may be sent during a handover procedure from the RAN node 3B to the RAN node 3A of the UE 1. That is, the RAN node 3A may be the target node of the handover, and the RAN node 3B may be the source node of the handover. In this case, the XnAP message may be a HANDOVER REQUEST ACKNOWLEDGE message. This handover may be a conditional handover. That is, during the (conditional) handover procedure of the UE 1, the target node (RAN node 3A) may indicate to the source node (RAN node 3B) whether the target node supports a function for jointly handling multiple interdependent QoS flows.

[0106] Additionally or alternatively, the RAN node 3A and the RAN node 3B may be a dual connectivity SN and MN, respectively. The XnAP message in step 1101 may be sent from the SN (RAN node 3A) to the MN (RAN node 3A) in a dual connectivity-related procedure. The dual connectivity-related procedure may be a secondary node addition procedure or a secondary node modification procedure. The dual connectivity-related procedure may be a conditional PSCell addition procedure or a conditional PSCell modification procedure. In this case, the XnAP message may be an S-NODE ADDITION REQUEST ACKNOWLEDGE or S-NODE MODIFICATION REQUEST ACKNOWLEDGE message. That is, in a dual connectivity-related procedure, the SN may indicate to the MN whether the SN supports a function for jointly handling multiple interdependent QoS flows.

[0107] The operation of RAN nodes 3A and 3B described with reference to Figure 11 may provide details of signaling between two RAN nodes 3 for support of handling of multiple QoS flows with multimodal interdependencies. Specifically, RAN node 3A may inform RAN node 3B whether the capability of jointly handling multiple interdependent QoS flows is supported by RAN node 3A.

[0108] Figure 12 shows an example of the format of a PDU Session Resource Setup Response Transfer IE that can be transmitted via the NGAP message of step 1001. In the example of Figure 12, the PDU Session Resource Setup Response Transfer IE may include a Dependency QoS Flows Handling Together Indicator IE 1201. Figure 13 shows an example of the format of the Dependency QoS Flows Handling Together Indicator IE 1201. In the example of Figure 13, the Dependency QoS Flows Handling Together Indicator IE 1201 includes a Dependency QoS Flows Handling Together Indicator IE 1301. The Dependency QoS Flows Handling Together Indicator IE 1301 is an enumerated type and may indicate "supported". That is, in the examples shown in Figures 12 and 13, if the PDU Session Resource Setup Response Transfer IE includes the Dependency QoS Flows Handling Together Indicator IE 1201, this indicates that the RAN node 3 supports the function of handling multiple QoS flows that are dependent on each other together.

[0109] The formats of other IEs that may be transmitted via the NGAP message in step 1001, such as a PDU Session Resource Modify Response Transfer IE, a Path Switch Request Transfer IE, and a Handover Request Acknowledge Transfer IE, may also be similar to those described with reference to Figures 12 and 13. The XnAP message in step 1101 may include an IE similar to the Dependency QoS Flows Handling Together Indicator IE 1201 or 1301 described with reference to Figures 12 and 13.

[0110] Third Embodiment This embodiment provides an improvement for coordinated handling of multiple QoS flows with multimodal interdependencies. Figure 14 shows an example of signaling on the user plane interface (i.e., NG-U interface) between the UPF 7 and the RAN node 3. In step 1401, when the UPF 7 forwards a packet (i.e., a user data packet) of a first QoS flow to the RAN node 3, the UPF 7 provides the RAN node 3 with one or more QoS flow group IEs for one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the RAN node 3. The UPF 7 may include these one or more QoS flow group IEs in a GTP-U Extension Header in a GTP-PDU (i.e., G-PDU) carrying the user data packet (i.e., T-PDU) of the first QoS flow. The UPF 7 may send a DL PDU SESSION INFORMATION frame or a DL PDU SET INFORMATION frame to the RAN node 3 that has been improved (or extended) to include one or more QoS flow group IEs. The improved (or extended) DL PDU SESSION INFORMATION frame or DL ​​PDU SET INFORMATION frame can be conveyed using the GTP-U Extension Header.

[0111] The one or more QoS flow group IEs sent in step 1401 may include at least one of the following: an IE indicating the number of one or more associated QoS flows; an IE indicating an identifier (e.g., QFI) for each of the one or more associated QoS flows; an IE indicating an identifier (e.g., QoS flow group coordination ID (QFGCI)) assigned to a QoS flow group that includes the first QoS flow and one or more associated QoS flows; an IE indicating the start of a dependency between the first QoS flow and one or more associated QoS flows; or an IE indicating the end of a dependency between the first QoS flow and one or more associated QoS flows.

[0112] The operation of the RAN node 3 and UPF 7 described with reference to Figure 14 can provide signaling details on the user plane interface (i.e., NG-U interface) between the UPF 7 and the RAN node 3 to support handling of multiple QoS flows with multimodal interdependencies. For example, when forwarding packets of a first QoS flow to the RAN node 3, the UPF 7 can provide the RAN node 3 with information regarding one or more associated QoS flows that should be handled in association with the first QoS flow in packet forwarding by the RAN node 3.

[0113] 15 shows an example of signaling on a user plane interface (i.e., Xn-U interface) between two RAN nodes 3. In step 1501, when the RAN node 3B forwards a packet (i.e., a user data packet) of a first QoS flow to the RAN node 3A, the RAN node 3B provides the RAN node 3A with one or more QoS flow group IEs for one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the RAN node 3A. The RAN node 3B may include these one or more QoS flow group IEs in a GTP-U Extension Header in a GTP-PDU (i.e., G-PDU) carrying the user data packet (i.e., T-PDU) of the first QoS flow. The RAN node 3B may send a DL PDU SESSION INFORMATION frame or a DL PDU SET INFORMATION frame to the RAN node 3A that has been modified (or extended) to include one or more QoS flow group IEs. The improved (or extended) DL PDU SESSION INFORMATION frame or DL ​​PDU SET INFORMATION frame can be conveyed using the GTP-U Extension Header.

[0114] The details of the one or more QoS flow group IEs sent in step 1501 may be similar to the details of the one or more QoS flow group IEs sent in step 1401 of FIG.

[0115] The operation of RAN nodes 3A and 3B described with reference to Figure 15 can provide details of signaling on the user plane interface (i.e., Xn-U interface) between two RAN nodes 3 to support handling of multiple QoS flows with multimodal interdependencies. For example, when RAN node 3B forwards packets of a first QoS flow to RAN node 3A, it can provide information to RAN node 3A regarding one or more associated QoS flows that should be handled in association with the first QoS flow in packet forwarding by RAN node 3A.

[0116] 16 shows an example of signaling on the user plane interface (i.e., F1-U interface) between the CU-UP 32 and the DU 35. In step 1601, when the CU-UP 32 transfers packets or PDCP PDUs of a first QoS flow (or DRB) to the DU 35, the CU-UP 32 provides the DU 35 with one or more QoS flow group IEs (or DRB group IEs) related to one or more associated QoS flows (or DRBs) to be handled in association with the first QoS flow (or DRB) in packet transfer by the DU 35. The CU-UP 32 may include these one or more QoS flow group IEs (or DRB group IEs) in a GTP-U Extension Header in a GTP-PDU (i.e., G-PDU) carrying packets or PDCP PDUs (i.e., T-PDU) of the first QoS flow (or DRB). The CU-UP 32 may send a DL PDU SESSION INFORMATION frame or a DL PDU SET INFORMATION frame modified (or extended) to include one or more QoS flow group IEs (or DRB group IEs) to the DU 35. The modified (or extended) DL PDU SESSION INFORMATION frame or the DL PDU SET INFORMATION frame may be conveyed using a GTP-U Extension Header.

[0117] Details of the one or more QoS flow group IEs (or DRB group IEs) sent in step 1601 may be similar to details of the one or more QoS flow group IEs (or DRB group IEs) sent in step 1401 of Figure 14. Alternatively, the one or more QoS flow group IEs (or DRB group IEs) sent in step 1601 may include at least one of the following: - an IE indicating the number of one or more associated DRBs, - an IE indicating an identifier for each of the one or more associated DRBs, - an IE indicating an identifier assigned to a DRB group including the first DRB and one or more associated DRBs, - an IE indicating the start of a dependency between the first DRB and one or more associated DRBs, or - an IE indicating the end of a dependency between the first DRB and one or more associated DRBs.

[0118] 16 can provide signaling details on the user plane interface (i.e., F1-U interface) between the CU-UP 32 and the DU 35 to support handling of multiple QoS flows or DRBs with multimodal interdependencies. For example, when the CU-UP 32 transfers PDCP PDUs of a first QoS flow (or DRB) to the DU 35, the CU-UP 32 can provide the DU 35 with information regarding one or more related QoS flows (or DRBs) that should be handled in association with the first QoS flow (or DRB) in packet forwarding by the DU 35.

[0119] Fig. 17 shows an example of the format of an improved (or extended) DL PDU Session Information frame. Note that the frame format of Fig. 17 does not necessarily have to be an improvement or extension of the DL PDU Session Information frame or the DL PDU SET INFORMATION frame. The frame format of Fig. 17 may be defined as a frame of a new PDU Session user plane protocol that is different from the DL PDU Session Information frame and the DL PDU SET INFORMATION frame.

[0120] In the example of Figure 17, the improved DL PDU Session Information frame or the frame of the new PDU Session user plane protocol may include one or more fields or IEs related to handling of multiple QoS flows with multimodal interdependencies. Specifically, the one or more IEs may include one or any combination of DQFI Ind, QFGCI, EDQFI, SDQFI, and DQFI.

[0121] The DQFI Ind field indicates the number of dependency QoS flows. A value of "0" means there are no other dependent QoS flows. A value of "1" means there is one dependent QoS flow, and its dependent QoS flow ID is indicated in the first order of the Dependent QoS Flow Identifier (DQFI) field. A value of "2" means there are two dependent QoS flows, and the first dependent QoS flow ID is indicated in the first order of the DQFI field, and the second dependent QoS flow ID is indicated in the second order of the DQFI field. The same rule applies when the DQFI Ind field is set to the value "3."

[0122] The SDQFI field indicates the start of the dependent QoS flow. The EDQFI field indicates the end of the dependent QoS flow. The DQFI field indicates the QFI of the dependent QoS flow. The QFGCI field indicates the QoS flow group coordination ID.

[0123] Figure 18 shows an example of the format of an improved (or extended) DL PDU Session Information frame. In the example of Figure 18, the improved DL PDU Session Information frame may include one or more fields or IEs related to handling of multiple QoS flows with multimodal interdependence in addition to the fields included in the DL PDU Session Information frame of 3GPP Release 18. As in the example of Figure 17, the fields or IEs related to handling of multiple QoS flows with multimodal interdependence may include one or any combination of DQFI Ind, QFGCI, EDQFI, SDQFI, and DQFI.

[0124] <Fourth Embodiment> This embodiment provides an improvement for coordinated handling of multiple QoS flows with multimodal interdependencies. Figure 19 is a flowchart showing an example of the operation of the RAN node 3. In step 1901, the RAN node 3 receives a request to set up, add, or modify a first QoS flow from the 5GC 4 (i.e., AMF 5 or SMF 6) or another RAN node. In step 1902, the RAN node 3 performs admission control for the first QoS flow.

[0125] Specifically, the RAN node 3 determines whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding. In other words, the RAN node 3 takes into account the interdependence of multiple QoS flows including the first QoS flow and its one or more associated QoS flows in admission control of these multiple QoS flows. For example, if the RAN node 3 rejects the setup, addition, or modification of any of the one or more associated QoS flows, the RAN node 3 may also reject the setup, addition, or modification of the first QoS flow. The RAN node 3 may accept the setup, addition, or modification of the first QoS flow on the condition that the setup, addition, or modification of some or all of the one or more associated QoS flows is accepted. One or more associated QoS flows may be critical QoS flows. The RAN node 3 may accept the setup, addition, or modification of the first QoS flow on the condition that the setup, addition, or modification of all associated critical QoS flows is accepted.

[0126] The RAN node 3 may receive a request to set up, add, or modify a first QoS flow from the 5GC 4 (i.e., AMF 5 or SMF 6) via a control message (i.e., NGAP message or N2 SM information). In this case, the control message may request the RAN node 3 to set up, add, or modify resources (e.g., radio resources and / or NG-U resources) for the first QoS flow and one or more associated QoS flows. The control message may be an INITIAL CONTEXT SETUP REQUEST, PDU SESSION RESOURCE SETUP REQUEST, PDU SESSION RESOURCE MODIFY REQUEST, or HANDOVER REQUEST message sent over the NGAP interface.

[0127] The RAN node 3 may include the first QoS flow in the same list as one or more associated QoS flows, provided that the one or more associated QoS flows are also included in one of the following lists: QoS Flow Accepted List, QoS Flow Failed to Setup List, QoS Flow Failed to Add or Modify List, QoS Flow Failed to Modify List, or QoS Flow Failed to Resume List. These lists may be included in a response message sent by the RAN node 3 to the 5GC 4 (i.e., AMF 5 or SMF 6), specifically in an INITIAL CONTEXT SETUP RESPONSE, PDU SESSION RESOURCE SETUP RESPONSE, PDU SESSION RESOURCE MODIFY RESPONSE, or HANDOVER REQUEST ACKNOWLEDGE message.

[0128] The RAN node 3 may include a first QoS flow in the same list as one or more associated QoS flows, provided that all associated critical QoS flows are included in one of these lists. A critical QoS flow may be a QoS flow whose packets are essential for forwarding. Multiple QoS flows may be associated with each other such that if one or more packets of one or more critical QoS flows are discarded at the RAN node 3 rather than forwarded to the UE 1, forwarding of one or more packets of the remaining one or more QoS flows is no longer required. Additionally or alternatively, multiple QoS flows may be associated with each other such that if the setup, addition, or modification of any of one or more critical QoS flows is not acceptable, the setup, addition, or modification of the remaining one or more QoS flows is no longer required.

[0129] During handover of UE 1 from RAN node 3B (i.e., source node) to RAN node 3A (i.e., target node), RAN node 3A may receive a request for setup of a first QoS flow from RAN node 3B via a control message (i.e., XnAP message). The handover may be a conditional handover. In this case, the control message may request RAN node 3A to setup resources (e.g., radio resources, NG-U resources, and / or Xn-U resources) for the first QoS flow and one or more associated QoS flows. The control message may be a HANDOVER REQUEST message sent over the XnAP interface.

[0130] The RAN node 3A may include the first QoS flow in the same list as one or more associated QoS flows, provided that the one or more associated QoS flows are also included in one of the following lists: QoS Flows Admitted List or QoS Flows Not Admitted List. The RAN node 3A may include the first QoS flow in the same list as one or more associated QoS flows, provided that all associated critical QoS flows are included in one of these lists. These lists can be included in a response message sent by the RAN node 3 to the 5GC 4 (i.e., AMF 5 or SMF 6), specifically in an INITIAL CONTEXT SETUP RESPONSE, PDU SESSION RESOURCE SETUP RESPONSE, PDU SESSION RESOURCE MODIFY RESPONSE, or HANDOVER REQUEST ACKNOWLEDGE message.

[0131] In a dual connectivity related procedure, the RAN node 3A may receive a request to set up a first QoS flow from the RAN node 3B via a control message (i.e., an XnAP message). The RAN node 3A may be a dual connectivity SN, and the RAN node 3B may be a dual connectivity MN. The dual connectivity related procedure may be a secondary node addition procedure or a secondary node modification procedure. The dual connectivity related procedure may be a conditional PSCell addition procedure or a conditional PSCell modification procedure. The control message may be an S-NODE ADDITION REQUEST or an S-NODE MODIFICATION REQUEST message sent over the XnAP interface.

[0132] The operation of the RAN node 3 or 3A described with reference to Fig. 19 may be used in combination with, for example, the operation of the RAN node 3 or 3A described with reference to Fig. 4 or 5 in the first embodiment. Specifically, the RAN node 3 or 3A may receive the request in step 1901 via the NGAP message in step 401 of Fig. 4 or the XnAP message in step 501 of Fig. 5.

[0133] According to the operations described with reference to Figure 19, the RAN node 3 can perform admission control for multiple QoS flows, taking into account multi-modal interdependencies between the multiple QoS flows.

[0134] Next, exemplary configurations of the UE 1, RAN node 3, AMF 5, SMF 6, and UPF 7 related to the above-described embodiments will be described below. FIG. 20 is a block diagram showing an exemplary configuration of the UE 1. The RF transceiver 2001 performs analog RF signal processing for communication with the RAN node 3. The RF transceiver 2001 may include multiple transceivers. The analog RF signal processing performed by the RF transceiver 2001 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 2001 is coupled to the antenna array 2002 and the baseband processor 2003. The RF transceiver 2001 receives modulation symbol data (or OFDM symbol data) from the baseband processor 2003, generates a transmit RF signal, and provides the transmit RF signal to the antenna array 2002. The RF transceiver 2001 also generates a baseband receive signal based on the receive RF signal received by the antenna array 2002 and provides the baseband receive signal to the baseband processor 2003. The RF transceiver 2001 may include an analog beamformer circuit for beamforming, which may include, for example, multiple phase shifters and multiple power amplifiers.

[0135] The baseband processor 2003 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communications. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, (c) transmission format (transmission frame) generation / decomposition, (d) transmission path coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) using Inverse Fast Fourier Transform (IFFT). Meanwhile, control plane processing includes communication management for Layer 1 (e.g., transmit power control), Layer 2 (e.g., radio resource management and hybrid automatic repeat request (HARQ) processing), and Layer 3 (e.g., signaling related to attachment, mobility, and call management).

[0136] For example, the digital baseband signal processing by the baseband processor 2003 may include signal processing of a PDCP layer, an RLC layer, a MAC layer, and a PH layer. Also, the control plane processing by the baseband processor 2003 may include processing of a Non-Access Stratum (NAS) protocol, an RRC protocol, MAC CEs, and Downlink Control Information (DCIs).

[0137] The baseband processor 2003 may perform MIMO encoding and precoding for beamforming.

[0138] The baseband processor 2003 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. In this case, the protocol stack processor that performs control plane processing may be shared with the application processor 2004, which will be described later.

[0139] The application processor 2004 is also referred to as a CPU, MPU, microprocessor, or processor core. The application processor 2004 may include multiple processors (multiple processor cores). The application processor 2004 executes a system software program (operating system (OS)) and various application programs (e.g., a calling application, a web browser, a mailer, a camera operation application, and a music playback application) read from the memory 2006 or other memories, thereby realizing various functions of the UE 1.

[0140] In some implementations, the baseband processor 2003 and the application processor 2004 may be integrated on a single chip, as indicated by the dashed line (2005) in Figure 20. In other words, the baseband processor 2003 and the application processor 2004 may be implemented as a single System on Chip (SoC) device 2005. An SoC device is sometimes called a system Large Scale Integration (LSI) or chipset.

[0141] The memory 2006 is volatile memory, nonvolatile memory, or a combination thereof. The memory 2006 may include multiple physically independent memory devices. The volatile memory may be, for example, static random access memory (SRAM), dynamic RAM (DRAM), or a combination thereof. The nonvolatile memory may be mask read only memory (MROM), electrically erasable programmable ROM (EEPROM), flash memory, a hard disk drive, or any combination thereof. For example, the memory 2006 may include an external memory device accessible from the baseband processor 2003, the application processor 2004, and the SoC 2005. The memory 2006 may also include an internal memory device integrated within the baseband processor 2003, the application processor 2004, or the SoC 2005. Furthermore, the memory 2006 may include memory within a Universal Integrated Circuit Card (UICC).

[0142] The memory 2006 may store one or more software modules (computer programs) 2007 containing instructions and data for processing by the UE 1. In some implementations, the baseband processor 2003 or the application processor 2004 may be configured to read and execute the software modules 2007 from the memory 2006 to perform the processing of the UE 1 described in one or more of the embodiments.

[0143] It should be noted that the control plane processing and operations performed by UE 1 described in the above embodiment can be realized by elements other than RF transceiver 2001 and antenna array 2002, namely, at least one of baseband processor 2003 and application processor 2004, and memory 2006 storing software module 2007.

[0144] FIG. 21 is a block diagram showing an example configuration of a RAN node 3. Referring to FIG. 21, the RAN node 3 includes an RF transceiver 2101, a network interface 2103, a processor 2104, and a memory 2105. The RF transceiver 2101 performs analog RF signal processing to communicate with multiple UEs including UE 1. The RF transceiver 2101 may include multiple transceivers. The RF transceiver 2101 is coupled to an antenna array 2102 and a processor 2104. The RF transceiver 2101 receives modulation symbol data from the processor 2104, generates a transmit RF signal, and provides the transmit RF signal to the antenna array 2102. The RF transceiver 2101 also generates a baseband receive signal based on the receive RF signal received by the antenna array 2102 and provides the baseband receive signal to the processor 2104. The RF transceiver 2101 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, multiple phase shifters and multiple power amplifiers.

[0145] The network interface 2103 is used to communicate with network nodes (e.g., other RAN nodes, and control and forwarding nodes of the core network), and may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0146] The processor 2104 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. The processor 2104 may include multiple processors. For example, the processor 2104 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 CPU or MPU) that performs control plane processing. The processor 2104 may include a digital beamformer module for beamforming. The digital beamformer module may include a MIMO encoder and a precoder.

[0147] The memory 2105 is configured by a combination of volatile memory and non-volatile memory. The volatile memory is, for example, SRAM or DRAM, or a combination thereof. The non-volatile memory is, for example, MROM, EEPROM, flash memory, or a hard disk drive, or any combination thereof. The memory 2105 may include storage located remotely from the processor 2104. In this case, the processor 2104 may access the memory 2105 via the network interface 2103 or another I / O interface.

[0148] The memory 2105 may store one or more software modules (computer programs) 2106 containing instructions and data for processing by the RAN node 3. In some implementations, the processor 2104 may be configured to read and execute the software modules 2106 from the memory 2105 to perform the processing of the RAN node 3 described in one or more of the embodiments.

[0149] The control plane processing and operations performed by the RAN node 3 described in the above embodiments can be realized by elements other than the RF transceiver 2101 and the antenna array 2102, namely the processor 2104 and the memory 2105 storing the software modules 2106.

[0150] If the RAN node 3 includes a CU 30 and one or more DUs 35, the CU 30, CU-CP 31, CU-UP 32, and DU 35 may not include an RF transceiver 2101 (and antenna array 2102).

[0151] Fig. 22 shows an example configuration of the AMF 5. The configurations of other core network nodes such as the SMF 6 and the UPF 7 may also be similar to the configuration shown in Fig. 22. Referring to Fig. 22, the AMF 5 includes a network interface 2201, a processor 2202, and a memory 2203.

[0152] The network interface 2201 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.

[0153] The processor 2202 may be, for example, a microprocessor, an MPU, or a CPU. The processor 2202 may include multiple processors.

[0154] The memory 2203 is composed of volatile memory and nonvolatile memory. The memory 2203 may include multiple 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 2203 may include storage located remotely from the processor 2202. In this case, the processor 2202 may access the memory 2203 via the network interface 2201 or the I / O interface.

[0155] The memory 2203 may store one or more software modules (computer programs) 2204 including instructions and data for performing the processing by the AMF 5 described in the above-described embodiments. In some implementations, the processor 2202 may be configured to read and execute the software modules 2204 from the memory 2203, thereby performing the processing by the AMF 5 described in the above-described embodiments.

[0156] As described with reference to Figures 20, 21, and 22, each of the processors included in the UE 1, RAN node 3, AMF 5, SMF 6, and UPF 7 according to the above-described embodiments can 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 (registered trademark) 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 or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0157] 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.

[0158] 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 devices (e.g., radio access network nodes, core network nodes, communication nodes) may naturally also be described as appendices directed to methods and programs. For example, some or all of the elements described in appendices 2-27, which are dependent on appendices 1, may also be described as appendices dependent on appendices 28 and 29, due to the same dependency relationship as appendices 2-27. Similarly, some or all of the elements described in appendices 31-43, which are dependent on appendices 31-43, may also be described as appendices dependent on appendices 44 and 45, due to the same dependency relationship as appendices 31-43. Some or all of the elements described in any appendice may be applicable to various hardware, software, recording means for recording software, systems, and methods.

[0159] (Supplementary Note 1) A radio access network node comprising means for receiving, from a core network or another radio access network node, a control message including one or more information elements indicating a plurality of Quality of Service (QoS) flows to be treated as associated with each other in packet forwarding by the radio access network node. (Supplementary Note 2) The radio access network node according to Supplementary Note 1, wherein the one or more information elements indicate a predetermined time difference within which a plurality of packets of the plurality of QoS flows need to be transmitted. (Supplementary Note 3) The radio access network node according to Supplementary Note 1 or 2, wherein the one or more information elements specify one or more critical QoS flows among the plurality of QoS flows. (Supplementary Note 4) The radio access network node according to Supplementary Note 3, wherein the plurality of QoS flows are associated with each other such that if one or more packets of the one or more critical QoS flows are discarded in the radio access network node without being forwarded to a wireless terminal, forwarding of one or more packets of the remaining one or more QoS flows is also no longer required. (Supplementary Note 5) The radio access network node according to Supplementary Note 3, wherein the multiple QoS flows are associated with each other such that if the setup, addition, or modification of any of the one or more critical QoS flows is not accepted, then the setup, addition, or modification of the remaining one or more QoS flows is also no longer required. (Supplementary Note 6) The radio access network node according to any one of Supplements 1 to 5, wherein the one or more information elements indicate an association between an identifier of a first QoS flow and one or more identifiers of one or more associated QoS flows to be handled in association with the first QoS flow. (Supplementary Note 7) The radio access network node according to any one of Supplements 1 to 6, wherein the one or more information elements indicate an association between an identifier of each of the multiple QoS flows and an identifier assigned to a QoS flow group corresponding to the multiple QoS flows.(Supplementary Note 8) The radio access network node according to any one of Supplements 1 to 7, wherein the receiving means is configured to receive the control message from the core network, and the control message requests the radio access network node to setup, add, or modify resources for the plurality of QoS flows. (Supplementary Note 9) The radio access network node according to Supplementary Note 8, wherein the control message is an INITIAL CONTEXT SETUP REQUEST, a PDU SESSION RESOURCE SETUP REQUEST, a PDU SESSION RESOURCE MODIFY REQUEST, or a HANDOVER REQUEST message transmitted on an NG Application Protocol (NGAP) interface. (Supplementary Note 10) The radio access network node according to Supplementary Note 9, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element that is included in a PDU Session Resource Setup Request Transfer, a PDU Session Resource Modify Request Transfer, or a Handover Request Transfer information element. (Supplementary Note 11) The radio access network node according to any one of Supplements 1 to 7, wherein the radio access network node is a target node in a handover of a wireless terminal, and the other radio access network node is a source node in the handover, and the receiving means is configured to receive the control message from the other radio access network node. (Supplementary Note 12) The radio access network node according to Supplementary Note 11, wherein the control message requests the radio access network node to set up resources for the multiple QoS flows. (Supplementary Note 13) The radio access network node according to Supplementary Note 11 or 12, wherein the control message is a HANDOVER REQUEST message sent on an Xn Application Protocol (XnAP) interface.(Supplementary Note 14) The radio access network node according to Supplementary Note 13, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element included in a PDU Session Resources To Be Setup List information element. (Supplementary Note 15) The radio access network node according to any one of Supplements 1 to 7, wherein the radio access network node is a secondary node of dual connectivity, the other radio access network node is a master node of the dual connectivity, and the receiving means is configured to receive the control message from the other radio access network node. (Supplementary Note 16) The radio access network node according to Supplementary Note 15, wherein the control message requests or authorizes the radio access network node to set up, add, or modify resources for the multiple QoS flows. (Supplementary Note 17) The radio access network node according to Supplementary Note 15 or 16, wherein the control message is an S-NODE ADDITION REQUEST or S-NODE MODIFICATION REQUEST message transmitted on an Xn Application Protocol (XnAP) interface. (Supplementary Note 18) The radio access network node according to Supplementary Note 17, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element included in a PDU Session Resource Setup Info - SN terminated, a PDU Session Resource Setup Info - MN terminated, a PDU Session Resource Modification Info - SN terminated, or a PDU Session Resource Modification Info - MN terminated information element.(Supplementary Note 19) The radio access network node according to any one of Supplements 1 to 7, wherein the radio access network node is a master node of dual connectivity, and the other radio access network node is a secondary node of the dual connectivity, and the receiving means is configured to receive the control message from the other radio access network node. (Supplementary Note 20) The radio access network node according to Supplementary Note 19, wherein the control message requests or authorizes the radio access network node to set up, add, or modify resources for the plurality of QoS flows. (Supplementary Note 21) The radio access network node according to Supplementary Note 19 or 20, wherein the control message is an S-NODE ADDITION REQUEST ACKNOWLEDGE, S-NODE MODIFICATION REQUEST ACKNOWLEDGE, or S-NODE MODIFICATION REQUIRED message sent on an Xn Application Protocol (XnAP) interface. (Supplementary Note 22) The radio access network node according to Supplementary Note 21, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element which is included in a PDU Session Resource Setup Response Info - SN terminated, a PDU Session Resource Modification Response Info - SN terminated, or a PDU Session Resource Modification Required Info - SN terminated information element. (Supplementary Note 23) The radio access network node according to any one of Supplements 1 to 22, wherein the plurality of QoS flows include a first QoS flow and a second QoS flow, and further comprising: means for determining whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of the second QoS flow.(Supplementary Note 24) The radio access network node according to any one of Supplements 1 to 23, wherein the multiple QoS flows are associated with each other such that packets need to be transmitted synchronously or within a predetermined time difference in packet transfer from the radio access network node to one radio terminal via one or more radio bearers. (Supplementary Note 25) The radio access network node according to any one of Supplements 1 to 24, wherein the multiple QoS flows are associated with each other such that if a packet of a certain QoS flow is discarded in the radio access network node without being transferred to a radio terminal, transfer of one or more packets of the remaining one or more QoS flows is also no longer required. (Supplementary Note 26) The radio access network node according to any one of Supplements 1 to 25, wherein the multiple QoS flows are associated with each other such that they need to be set up, added or modified together. (Supplementary Note 27) The radio access network node according to any one of Supplements 1 to 26, wherein the multiple QoS flows are associated with each other such that if the setup, addition, or modification of a certain QoS flow is not accepted, the setup, addition, or modification of one or more remaining QoS flows is also no longer required. (Supplementary Note 28) A method performed by a radio access network node, comprising receiving, from a core network or another radio access network node, a control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be handled in association with each other in packet forwarding by the radio access network node. (Supplementary Note 29) A program for causing a computer to perform a method for a radio access network node, the program comprising receiving, from a core network or another radio access network node, a control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be handled in association with each other in packet forwarding by the radio access network node.(Supplementary Note 30) A core network node comprising means for sending to a radio access network node a control message including one or more information elements indicating a plurality of Quality of Service (QoS) flows to be treated as associated with each other in packet forwarding by the radio access network node. (Supplementary Note 31) The core network node according to Supplementary Note 30, wherein the one or more information elements indicate a predetermined time difference within which a plurality of packets of the plurality of QoS flows need to be transmitted. (Supplementary Note 32) The core network node according to Supplementary Note 30 or 31, wherein the one or more information elements specify one or more critical QoS flows among the plurality of QoS flows. (Supplementary Note 33) The core network node according to Supplementary Note 32, wherein the plurality of QoS flows are associated with each other such that if one or more packets of one or more critical QoS flows are discarded at the radio access network node without being forwarded to a radio terminal, forwarding of one or more packets of the remaining one or more QoS flows is also no longer required. (Supplementary Note 34) The core network node according to Supplementary Note 32, wherein the multiple QoS flows are associated with each other such that if the setup, addition, or modification of any of the one or more critical QoS flows is not accepted, then the setup, addition, or modification of the remaining one or more QoS flows is also no longer required. (Supplementary Note 35) The core network node according to any one of Supplements 30 to 34, wherein the one or more information elements indicate an association between an identifier of a first QoS flow and one or more identifiers of one or more associated QoS flows to be handled in association with the first QoS flow. (Supplementary Note 36) The core network node according to any one of Supplements 30 to 35, wherein the one or more information elements indicate an association between an identifier of each of the multiple QoS flows and an identifier assigned to a QoS flow group corresponding to the multiple QoS flows.(Supplementary Note 37) The core network node according to any one of Supplements 30 to 36, wherein the control message requests the radio access network node to setup, add or modify resources for the plurality of QoS flows. (Supplementary Note 38) The core network node according to Supplementary Note 37, wherein the control message is an INITIAL CONTEXT SETUP REQUEST, PDU SESSION RESOURCE SETUP REQUEST, PDU SESSION RESOURCE MODIFY REQUEST or HANDOVER REQUEST message sent on an NG Application Protocol (NGAP) interface. (Supplementary Note 39) The core network node according to Supplementary Note 38, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element which is included in a PDU Session Resource Setup Request Transfer, PDU Session Resource Modify Request Transfer or Handover Request Transfer information element. (Supplementary Note 40) The core network node according to any one of Supplements 30 to 39, wherein the multiple QoS flows are associated with each other such that packets need to be transmitted synchronously or within a predetermined time difference in packet forwarding from the radio access network node to one radio terminal via one or more radio bearers. (Supplementary Note 41) The core network node according to any one of Supplements 30 to 40, wherein the multiple QoS flows are associated with each other such that if a packet of a certain QoS flow is discarded in the radio access network node without being forwarded to a radio terminal, forwarding of one or more packets of the remaining one or more QoS flows is also no longer required. (Supplementary Note 42) The core network node according to any one of Supplements 30 to 41, wherein the multiple QoS flows are associated with each other such that they need to be set up, added or modified together.(Supplementary Note 43) The core network node according to any one of Supplements 30 to 42, wherein the multiple QoS flows are associated with each other such that if the setup, addition, or modification of a certain QoS flow is not accepted, then the setup, addition, or modification of one or more remaining QoS flows is also no longer required. (Supplementary Note 44) A method performed by a core network node, comprising sending to the radio access network node a control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be handled in association with each other in packet forwarding by the radio access network node. (Supplementary Note 45) A program for causing a computer to perform a method for a core network node, comprising sending to the radio access network node a control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be handled in association with each other in packet forwarding by the radio access network node. (Supplementary Note 46) A first radio access network node comprising means for sending to a second radio access network node a control message including one or more information elements indicating a plurality of Quality of Service (QoS) flows to be treated in association with each other in packet forwarding by the second radio access network node. (Supplementary Note 47) The first radio access network node according to Supplementary Note 46, wherein the one or more information elements indicate a predetermined time difference within which a plurality of packets of the plurality of QoS flows need to be transmitted. (Supplementary Note 48) The first radio access network node according to Supplementary Note 46 or 47, wherein the one or more information elements specify one or more critical QoS flows among the plurality of QoS flows.(Supplementary Note 49) The first radio access network node of Supplementary Note 48, wherein the plurality of QoS flows are associated with each other such that if one or more packets of the one or more critical QoS flows are discarded in the radio access network node without being forwarded to a wireless terminal, forwarding of one or more packets of the remaining one or more QoS flows is no longer required. (Supplementary Note 50) The first radio access network node of Supplementary Note 48, wherein the plurality of QoS flows are associated with each other such that if setup, addition, or modification of any of the one or more critical QoS flows is not accepted, setup, addition, or modification of the remaining one or more QoS flows is no longer required. (Supplementary Note 51) The first radio access network node of any one of Supplements 46 to 50, wherein the one or more information elements indicate an association between an identifier of a first QoS flow and one or more identifiers of one or more associated QoS flows to be handled in association with the first QoS flow. (Supplementary Note 52) The first radio access network node according to any one of Supplements 46 to 51, wherein the one or more information elements indicate an association between an identifier of each of the plurality of QoS flows and an identifier assigned to a QoS flow group corresponding to the plurality of QoS flows. (Supplementary Note 53) The first radio access network node according to any one of Supplements 46 to 52, wherein the first radio access network node is a source node in a handover of a wireless terminal, and the second radio access network node is a target node in the handover. (Supplementary Note 54) The first radio access network node according to Supplementary Note 53, wherein the control message requests the second radio access network node to set up resources for the plurality of QoS flows. (Supplementary Note 55) The first radio access network node according to Supplementary Note 53 or 54, wherein the control message is a HANDOVER REQUEST message transmitted on an Xn Application Protocol (XnAP) interface.(Supplementary Note 56) The first radio access network node according to Supplementary Note 55, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element included in a PDU Session Resources To Be Setup List information element. (Supplementary Note 57) The first radio access network node according to any one of Supplements 46 to 52, wherein the first radio access network node is a master node of dual connectivity, and the second radio access network node is a secondary node of the dual connectivity. (Supplementary Note 58) The first radio access network node according to Supplementary Note 57, wherein the control message requests or authorizes the second radio access network node to set up, add, or modify resources for the multiple QoS flows. 59. The first radio access network node according to Supplementary Note 57 or 58, wherein the control message is an S-NODE ADDITION REQUEST or S-NODE MODIFICATION REQUEST message sent over an Xn Application Protocol (XnAP) interface. 60. The first radio access network node according to Supplementary Note 59, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element which is included in a PDU Session Resource Setup Info - SN terminated, a PDU Session Resource Setup Info - MN terminated, a PDU Session Resource Modification Info - SN terminated, or a PDU Session Resource Modification Info - MN terminated information element.(Supplementary Note 61) The first radio access network node according to any one of Supplements 46 to 52, wherein the first radio access network node is a secondary node in dual connectivity, and the second radio access network node is a master node in the dual connectivity. (Supplementary Note 62) The first radio access network node according to Supplementary Note 61, wherein the control message requests or authorizes the second radio access network node to set up, add, or modify resources for the multiple QoS flows. (Supplementary Note 63) The first radio access network node according to Supplementary Note 61 or 62, wherein the control message is an S-NODE ADDITION REQUEST ACKNOWLEDGE, S-NODE MODIFICATION REQUEST ACKNOWLEDGE, or S-NODE MODIFICATION REQUIRED message sent on an Xn Application Protocol (XnAP) interface. (Supplementary Note 64) The first radio access network node according to Supplementary Note 63, wherein the one or more information elements are included in a QoS Flow Level QoS Parameters information element which is included in a PDU Session Resource Setup Response Info - SN terminated, a PDU Session Resource Modification Response Info - SN terminated, or a PDU Session Resource Modification Required Info - SN terminated information element. (Supplementary Note 65) The first radio access network node according to any one of Supplements 46 to 64, wherein the multiple QoS flows are associated with each other such that packets need to be transmitted synchronously or within a predetermined time difference in packet transfer from the radio access network node to one radio terminal via one or more radio bearers.(Supplementary Note 66) The first radio access network node according to any one of Supplements 46 to 65, wherein the plurality of QoS flows are associated with each other such that if a packet of a certain QoS flow is discarded at the radio access network node without being forwarded to a wireless terminal, forwarding of one or more packets of the remaining one or more QoS flows is no longer required. (Supplementary Note 67) The first radio access network node according to any one of Supplementary Notes 46 to 66, wherein the plurality of QoS flows are associated with each other such that they need to be set up, added or modified together. (Supplementary Note 68) The first radio access network node according to any one of Supplementary Notes 46 to 67, wherein the plurality of QoS flows are associated with each other such that if the setup, addition or modification of a certain QoS flow is not accepted, then the setup, addition or modification of the remaining one or more QoS flows is no longer required. (Supplementary Note 69) A method performed by a first radio access network node, comprising sending, to a second radio access network node, a control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be handled in association with each other in packet forwarding by the second radio access network node. (Supplementary Note 70) A program for causing a computer to perform a method for a first radio access network node, comprising: sending, to the second radio access network node, a control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be handled in association with each other in packet forwarding by the second radio access network node. (Supplementary Note 71) A radio access network node, comprising: means for sending, to a core network or another radio access network node, a control message including an information element indicating whether a function for collectively handling multiple Quality of Service (QoS) flows that depend on each other is supported by the radio access network node.72. The radio access network node of claim 71, wherein the sending means is configured to send the control message to the core network. 73. The radio access network node of claim 72, wherein the control message is an INITIAL CONTEXT SETUP RESPONSE, a PDU SESSION RESOURCE SETUP RESPONSE, a PDU SESSION RESOURCE MODIFY RESPONSE, a PATH SWITCH REQUEST, or a HANDOVER REQUEST ACKNOWLEDGE message sent over an NG Application Protocol (NGAP) interface. 74. The radio access network node of claim 73, wherein the information element is included in a PDU Session Resource Setup Response Transfer, a PDU Session Resource Modify Response Transfer, a Path Switch Request Transfer, or a Handover Request Acknowledge Transfer information element. (Supplementary Note 75) The radio access network node according to Supplementary Note 71, wherein the radio access network node is a target node in a handover of a wireless terminal, and the other radio access network node is a source node in the handover, and the sending means is configured to send the control message to the other radio access network node. (Supplementary Note 76) The radio access network node according to Supplementary Note 75, wherein the control message is a HANDOVER REQUEST ACKNOWLEDGE message sent on an Xn Application Protocol (XnAP) interface.(Supplementary Note 77) The radio access network node according to Supplementary Note 71, wherein the radio access network node is a secondary node in dual connectivity, and the other radio access network node is a master node in the dual connectivity, and the sending means is configured to send the control message to the other radio access network node. (Supplementary Note 78) The radio access network node according to Supplementary Note 77, wherein the control message is an S-NODE ADDITION REQUEST ACKNOWLEDGE or S-NODE MODIFICATION REQUEST ACKNOWLEDGE message transmitted on an Xn Application Protocol (XnAP) interface. (Supplementary Note 79) A method performed by a radio access network node, comprising sending a control message to a core network or another radio access network node, the control message including an information element indicating whether a function for jointly handling multiple interdependent Quality of Service (QoS) flows is supported by the radio access network node. (Supplementary Note 80) A program for causing a computer to perform a method for a radio access network node, the method comprising sending to a core network or another radio access network node a control message including an information element indicating whether a function for collectively handling multiple Quality of Service (QoS) flows that are dependent on each other is supported by the radio access network node. (Supplementary Note 81) A core network node comprising means for receiving from the radio access network node a control message including an information element indicating whether a function for collectively handling multiple Quality of Service (QoS) flows that are dependent on each other is supported by the radio access network node.82. The core network node of claim 81, wherein the control message is an INITIAL CONTEXT SETUP RESPONSE, PDU SESSION RESOURCE SETUP RESPONSE, PDU SESSION RESOURCE MODIFY RESPONSE, PATH SWITCH REQUEST, or HANDOVER REQUEST ACKNOWLEDGE message sent over an NG Application Protocol (NGAP) interface. 83. The core network node of claim 82, wherein the information element is included in a PDU Session Resource Setup Response Transfer, a PDU Session Resource Modify Response Transfer, a Path Switch Request Transfer, or a Handover Request Acknowledge Transfer information element. 84. A method performed by a core network node, comprising receiving from the radio access network node a control message including an information element indicating whether a function for jointly handling multiple interdependent Quality of Service (QoS) flows is supported by the radio access network node. (Supplementary Note 85) A program for causing a computer to perform a method for a core network node, comprising: receiving, from a radio access network node, a control message including an information element indicating whether a function for jointly handling multiple Quality of Service (QoS) flows that are dependent on each other is supported by the radio access network node. (Supplementary Note 86) A first radio access network node, comprising means for receiving, from a second radio access network node, a control message including an information element indicating whether a function for jointly handling multiple Quality of Service (QoS) flows that are dependent on each other is supported by the second radio access network node.(Supplementary Note 87) The first radio access network node according to Supplementary Note 86, wherein the first radio access network node is a source node in a handover of a wireless terminal, and the second radio access network node is a target node in the handover. (Supplementary Note 88) The first radio access network node according to Supplementary Note 87, wherein the control message is a HANDOVER REQUEST ACKNOWLEDGE message transmitted on an Xn Application Protocol (XnAP) interface. (Supplementary Note 89) The first radio access network node according to Supplementary Note 86, wherein the first radio access network node is a master node in dual connectivity, and the second radio access network node is a secondary node in the dual connectivity. 90. The first radio access network node of claim 89, wherein the control message is an S-NODE ADDITION REQUEST ACKNOWLEDGE or S-NODE MODIFICATION REQUEST ACKNOWLEDGE message sent over an Xn Application Protocol (XnAP) interface. 91. A method performed by a first radio access network node, comprising receiving, from the second radio access network node, a control message including an information element indicating whether or not the second radio access network node supports a function for jointly handling multiple interdependent Quality of Service (QoS) flows. 92. A program for causing a first radio access network node to perform a method for a first radio access network node, comprising receiving, from the second radio access network node, a control message including an information element indicating whether or not the second radio access network node supports a function for jointly handling multiple interdependent Quality of Service (QoS) flows.(Supplementary Note 93) A radio access network node comprising: means for receiving a request for setup, addition, or modification of a first Quality of Service (QoS) flow from a core network or another radio access network node; and means for determining whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the radio access network node. (Supplementary Note 94) The radio access network node according to Supplementary Note 93, wherein the receiving means is configured to receive the request from the core network via a control message, the control message requesting the radio access network node to setup, add, or modify resources for the first QoS flow and the one or more associated QoS flows. 95. The radio access network node of claim 94, wherein the control message is an INITIAL CONTEXT SETUP REQUEST, a PDU SESSION RESOURCE SETUP REQUEST, a PDU SESSION RESOURCE MODIFY REQUEST, or a HANDOVER REQUEST message sent over an NG Application Protocol (NGAP) interface. 96. The radio access network node of claim 95, wherein the determining means is configured to include the first QoS flow in the same list as the one or more associated QoS flows, on condition that the one or more associated QoS flows are included in any of the following lists: QoS Flow Accepted List, QoS Flow Failed to Setup List, QoS Flow Failed to Add or Modify List, QoS Flow Failed to Modify List, or QoS Flow Failed to Resume List.(Supplementary Note 97) The radio access network node of Supplementary Note 93, wherein the radio access network node is a target node in a handover of a wireless terminal, and the other radio access network node is a source node in the handover, and wherein the receiving means is configured to receive the request from the other radio access network node via a handover related message, the handover related message requesting the radio access network node to set up resources for the first QoS flow and the one or more associated QoS flows. (Supplementary Note 98) The radio access network node of Supplementary Note 97, wherein the handover related message is a HANDOVER REQUEST message sent on an Xn Application Protocol (XnAP) interface. (Supplementary Note 99) The radio access network node of Supplementary Note 98, wherein the determining means is configured to include the first QoS flow in the same list as the one or more associated QoS flows, on condition that the one or more associated QoS flows are included in either of the following lists: QoS Flows Admitted List, or QoS Flows not Admitted List. (Supplementary Note 100) The radio access network node according to Supplementary Note 93, wherein the radio access network node is a secondary node of dual connectivity, and the other radio access network node is a master node of the dual connectivity, and the receiving means is configured to receive the request from the other radio access network node via a dual connectivity related message, the dual connectivity related message requesting the radio access network node to set up, add or modify resources for the first QoS flow and the one or more associated QoS flows.(Supplementary Note 101) The radio access network node according to Supplementary Note 100, wherein the dual connectivity related message is an S-NODE ADDITION REQUEST or an S-NODE MODIFICATION REQUEST message transmitted on an Xn Application Protocol (XnAP) interface. (Supplementary Note 102) The radio access network node according to any one of Supplements 93 to 101, wherein the first QoS flow and the one or more associated QoS flows are associated with each other such that packets need to be transmitted synchronously or within a predetermined time difference in packet forwarding from the radio access network node to one radio terminal via one or more radio bearers. (Supplementary Note 103) The radio access network node according to any one of Supplements 93 to 102, wherein the first QoS flow and the one or more associated QoS flows are associated with each other such that if a packet of a QoS flow is discarded in the radio access network node without being forwarded to a radio terminal, forwarding of one or more packets of the remaining one or more QoS flows is also no longer required. (Supplementary Note 104) The radio access network node according to any one of Supplementary Notes 93 to 103, wherein the first QoS flow and the one or more associated QoS flows are associated with each other such that they need to be set up, added or modified together. (Supplementary Note 105) The radio access network node according to any one of Supplementary Notes 93 to 104, wherein the first QoS flow and the one or more associated QoS flows are associated with each other such that if the set up, addition or modification of a QoS flow is not accepted, the set up, addition or modification of the remaining one or more QoS flows is also no longer required.(Supplementary Note 106) A method performed by a radio access network node, comprising: receiving a request for setup, addition, or modification of a first Quality of Service (QoS) flow from a core network or another radio access network node, and determining whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the radio access network node. (Supplementary Note 107) A program for causing a computer to perform a method for a radio access network node, the method comprising: receiving a request for setup, addition, or modification of a first Quality of Service (QoS) flow from a core network or another radio access network node, and determining whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the radio access network node. (Supplementary Note 108) A first communications node comprising: means for, when forwarding packets of a first Quality of Service (QoS) flow to a second communications node, providing to the second communications node one or more QoS flow group information elements related to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node. (Supplementary Note 109) The first communications node according to Supplementary Note 108, wherein the providing means is configured to include the one or more QoS flow group information elements in a General Packet Radio System (GPRS) Tunneling Protocol (GTP) User Plane (GTP-U) Extension Header in a GTP Protocol Data Unit (PDU).(Supplementary Note 110) The first communications node according to Supplementary Note 108 or 109, wherein the providing means is configured to send to the second communications node a DL PDU SESSION INFORMATION frame or a DL PDU SET INFORMATION frame modified to include the one or more QoS flow group information elements. (Supplementary Note 111) The one or more QoS flow group information elements include at least one of the following: an information element indicating the number of the one or more associated QoS flows, an information element indicating an identifier of each of the one or more associated QoS flows, an information element indicating an identifier assigned to a QoS flow group including the first QoS flow and the one or more associated QoS flows, an information element indicating a start of a dependency between the first QoS flow and the one or more associated QoS flows, or an information element indicating an end of a dependency between the first QoS flow and the one or more associated QoS flows. The first communications node according to any one of Supplementary Notes 108 to 110. (Supplementary note 112) The first communications node according to any one of Supplements 108 to 111, wherein the first communications node is a User Plane Function (UPF) in a core network, and the second communications node is a radio access network node or a Central Unit User Plane (CU-UP) of the radio access network node. (Supplementary note 113) The first communications node according to any one of Supplements 108 to 111, wherein the first communications node is a radio access network node, and the second communications node is another radio access network node. (Supplementary note 114) The first communications node according to any one of Supplements 108 to 111, wherein the first communications node is a Central Unit User Plane (CU-UP) of a radio access network node, and the second communications node is a Distributed Unit (DU) of the radio access network node.(Supplementary note 115) A method performed by a first communications node, comprising, when forwarding packets of a first Quality of Service (QoS) flow to a second communications node, providing to the second communications node one or more QoS flow group information elements related to one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the second communications node. (Supplementary note 116) A program for causing a computer to perform a method for a first communications node, comprising, when forwarding packets of a first Quality of Service (QoS) flow to the second communications node, providing to the second communications node one or more QoS flow group information elements related to one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the second communications node. (Supplementary Note 117) A second communications node comprising: means for receiving, upon receiving packets of a first Quality of Service (QoS) flow from the first communications node, one or more QoS flow group information elements related to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node. (Supplementary Note 118) The second communications node of Supplementary Note 117, wherein the receiving means is configured to receive the one or more QoS flow group information elements via a General Packet Radio System (GPRS) Tunneling Protocol (GTP) User Plane (GTP-U) Extension Header in a GTP Protocol Data Unit (PDU). (Supplementary Note 119) The second communications node according to Supplementary Note 117 or 118, wherein the receiving means is configured to receive from the first communications node a DL PDU SESSION INFORMATION frame or a DL PDU SET INFORMATION frame modified to include the one or more QoS flow group information elements.(Supplementary note 120) The one or more QoS flow group information elements include at least one of the following: - an information element indicating the number of the one or more associated QoS flows, - an information element indicating an identifier of each of the one or more associated QoS flows, - an information element indicating an identifier assigned to a QoS flow group including the first QoS flow and the one or more associated QoS flows, - an information element indicating a start of a dependency between the first QoS flow and the one or more associated QoS flows, or - an information element indicating an end of a dependency between the first QoS flow and the one or more associated QoS flows The second communications node according to any one of Supplementary notes 117 to 119. (Supplementary note 121) The second communications node according to any one of Supplementary notes 117 to 120, wherein the first communications node is a User Plane Function (UPF) in a core network, and the second communications node is a radio access network node or a Central Unit User Plane (CU-UP) of the radio access network node. (Supplementary Note 122) The second communications node according to any one of Supplements 117 to 120, wherein the first communications node is a radio access network node, and the second communications node is another radio access network node. (Supplementary Note 123) The second communications node according to any one of Supplements 117 to 120, wherein the first communications node is a Central Unit User Plane (CU-UP) of a radio access network node, and the second communications node is a Distributed Unit (DU) of the radio access network node. (Supplementary Note 124) A method performed by a second communications node, comprising, upon receiving packets of a first Quality of Service (QoS) flow from the first communications node, receiving from the first communications node one or more QoS flow group information elements related to one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the second communications node.(Supplementary Note 125) A program for causing a computer to perform a method for a second communication node, the method comprising, when receiving packets of a first Quality of Service (QoS) flow from a first communication node, receiving from the first communication node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communication node.

[0160] This application claims priority based on Japanese Patent Application No. 2024-055212, filed March 29, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0161] 1 UE 2 NG-RAN 3 RAN node 4 5GC 5 AMF 6 SMF 7 UPF 8 DN 2103 Baseband processor 2104 Application processor 2106 Memory 2107 Modules 2204 Processor 2205 Memory 2206 Modules 2302 Processor 2303 Memory 2304 Modules

Claims

1. A radio access network node comprising: means for receiving, from a core network or another radio access network node, a control message including one or more information elements indicating a plurality of Quality of Service (QoS) flows to be treated in association with each other in packet forwarding by the radio access network node.

2. A radio access network node according to claim 1, wherein the one or more information elements indicate a predetermined time difference within which packets of the plurality of QoS flows must be transmitted.

3. A radio access network node according to claim 1 or 2, wherein the one or more information elements specify one or more critical QoS flows of the plurality of QoS flows.

4. A radio access network node according to any one of claims 1 to 3, wherein the one or more information elements indicate an association between an identifier of each of the plurality of QoS flows and an identifier assigned to a QoS flow group corresponding to the plurality of QoS flows.

5. A radio access network node according to any one of claims 1 to 4, wherein the receiving means is configured to receive the control message from the core network, the control message requesting the radio access network node to set up, add or modify resources for the plurality of QoS flows.

6. A radio access network node according to any one of claims 1 to 4, wherein the radio access network node is a target node in a handover of a radio terminal, and the other radio access network node is a source node in the handover, and the receiving means is configured to receive the control message from the other radio access network node.

7. A radio access network node according to any one of claims 1 to 4, wherein the radio access network node is a secondary node of dual connectivity, the other radio access network node is a master node of the dual connectivity, and the receiving means is configured to receive the control message from the other radio access network node.

8. A radio access network node according to any one of claims 1 to 4, wherein the radio access network node is a master node of dual connectivity, and the other radio access network node is a secondary node of the dual connectivity, and the receiving means is configured to receive the control message from the other radio access network node.

9. A radio access network node according to any one of claims 1 to 8, wherein the plurality of QoS flows comprises a first QoS flow and a second QoS flow, and further comprising means for determining whether to accept the setup, addition or modification of the first QoS flow depending on whether to accept the setup, addition or modification of the second QoS flow.

10. A method performed by a radio access network node, comprising receiving a control message from a core network or another radio access network node, the control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be treated in association with each other in packet forwarding by the radio access network node.

11. A core network node comprising: means for sending a control message to a radio access network node, the control message including one or more information elements indicating a plurality of Quality of Service (QoS) flows to be treated in association with each other in packet forwarding by the radio access network node.

12. A method performed by a core network node, comprising sending a control message to a radio access network node, the control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be treated in association with each other in packet forwarding by the radio access network node.

13. A first radio access network node comprising means for sending a control message to a second radio access network node, the control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be treated in association with each other in packet forwarding by the second radio access network node.

14. A method performed by a first radio access network node, comprising sending a control message to a second radio access network node, the control message including one or more information elements indicating multiple Quality of Service (QoS) flows to be treated in association with each other in packet forwarding by the second radio access network node.

15. A radio access network node comprising: means for sending a control message to a core network or another radio access network node, the control message including an information element indicating whether a function for jointly handling multiple interdependent Quality of Service (QoS) flows is supported by the radio access network node.

16. The radio access network node according to claim 15, wherein the sending means is configured to send the control message to the core network.

17. The radio access network node according to claim 15, wherein the radio access network node is a target node in a handover of a wireless terminal, and the other radio access network node is a source node in the handover, and the sending means is configured to send the control message to the other radio access network node.

18. The radio access network node according to claim 15, wherein the radio access network node is a secondary node of dual connectivity, and the other radio access network node is a master node of the dual connectivity, and the sending means is configured to send the control message to the other radio access network node.

19. A method performed by a radio access network node, comprising sending a control message to a core network or another radio access network node, the control message including an information element indicating whether the radio access network node supports the capability to collectively handle multiple interdependent Quality of Service (QoS) flows.

20. A core network node comprising: means for receiving, from a radio access network node, a control message including an information element indicating whether the radio access network node supports a function for jointly handling multiple interdependent Quality of Service (QoS) flows.

21. A method performed by a core network node, comprising receiving from a radio access network node a control message including an information element indicating whether the radio access network node supports the capability to collectively handle multiple interdependent Quality of Service (QoS) flows.

22. A first radio access network node comprising: means for receiving, from a second radio access network node, a control message including an information element indicating whether the second radio access network node supports a function for jointly handling multiple interdependent Quality of Service (QoS) flows.

23. A method performed by a first radio access network node, comprising receiving from a second radio access network node a control message including an information element indicating whether the second radio access network node supports the capability to collectively handle multiple interdependent Quality of Service (QoS) flows.

24. A radio access network node comprising: means for receiving a request for the setup, addition, or modification of a first Quality of Service (QoS) flow from a core network or another radio access network node; and means for determining whether to accept the setup, addition, or modification of the first QoS flow depending on whether to accept the setup, addition, or modification of one or more associated QoS flows to be handled in association with the first QoS flow in packet forwarding by the radio access network node.

25. The radio access network node of claim 24, wherein the means for receiving is configured to receive the request from the core network via a control message, the control message requesting the radio access network node to set up, add, or modify resources for the first QoS flow and the one or more associated QoS flows.

26. The radio access network node of claim 24, wherein the radio access network node is a target node in a handover of a wireless terminal, and the other radio access network node is a source node in the handover, and the receiving means is configured to receive the request from the other radio access network node via a handover related message, the handover related message requesting the radio access network node to set up resources for the first QoS flow and the one or more associated QoS flows.

27. The radio access network node of claim 24, wherein the radio access network node is a secondary node in dual connectivity, and the other radio access network node is a master node in the dual connectivity, and the receiving means is configured to receive the request from the other radio access network node via a dual connectivity related message, the dual connectivity related message requesting the radio access network node to set up, add or modify resources for the first QoS flow and the one or more associated QoS flows.

28. A method performed by a radio access network node, comprising: receiving a request from a core network or another radio access network node to set up, add, or modify a first Quality of Service (QoS) flow; and determining whether to accept the set up, addition, or modification of the first QoS flow depending on whether to accept the set up, addition, or modification of one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the radio access network node.

29. A first communications node comprising: means for, when forwarding packets of a first Quality of Service (QoS) flow to a second communications node, providing to the second communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

30. The first communications node of claim 29, wherein the providing means is configured to include the one or more QoS flow group information elements in a General Packet Radio System (GPRS) Tunneling Protocol (GTP) User Plane (GTP-U) Extension Header in a GTP Protocol Data Unit (PDU).

31. A method performed by a first communications node, comprising, when forwarding packets of a first Quality of Service (QoS) flow to a second communications node, providing to the second communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

32. A second communications node, comprising: means for, upon receiving packets of a first Quality of Service (QoS) flow from a first communications node, receiving from the first communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

33. A method performed by a second communications node, comprising, upon receiving packets of a first Quality of Service (QoS) flow from a first communications node, receiving from the first communications node one or more QoS flow group information elements relating to one or more associated QoS flows to be treated in association with the first QoS flow in packet forwarding by the second communications node.

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