Communication Control Method

Abstract

To provide a communication control method that can authenticate a network node without affecting a core network.SOLUTION: A communication control method according to an aspect is a communication control method used for a cellular communication system. The communication control method has a step of transmitting, by a base station, a network node identifier allocated to a network node to an operation management device. The communication control method has a step of transmitting, by the network node, the network node identifier to the operation management device. The communication control method further has a step of performing, by the operation management device, authentication of the network node based on the network node identifier received from the base station and the network node identifier received from the network node.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a communication control method for use in a cellular communication system. [Background technology]

[0002] 3GPP (Third Generation Partnership Project) (registered trademark, the same applies hereinafter), a standardization project for cellular communication systems, is considering the introduction of a new relay node called an IAB (Integrated Access and Backhaul) node (see, for example, Non-Patent Document 1). One or more relay nodes intervene in communication between a base station and a user device and relay this communication. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 38.300 V17.2.0(2022-09) Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a communication control method capable of authenticating a network node without affecting the core network. [Means for solving the problem]

[0005] A communication control method according to a first aspect is a communication control method used in a cellular communication system. The communication control method includes a step in which a base station transmits a network node identifier assigned to a network node to an operation management device. The communication control method also includes a step in which the network node transmits the network node identifier to the operation management device. The communication control method further includes a step in which the operation management device authenticates the network node based on the network node identifier received from the base station and the network node identifier received from the network node. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a cellular communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram showing the relationship between IAB nodes, parent nodes, and child nodes. [Figure 3] FIG. 3 is a diagram illustrating an example configuration of a gNB (base station) according to an embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of an IAB node (relay node) according to an embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of the configuration of a UE (user equipment) according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of a protocol stack for an RRC connection and a NAS connection of an IAB-MT. [Figure 7] FIG. 7 is a diagram illustrating an example of a protocol stack for the F1-U protocol. [Figure 8] FIG. 8 is a diagram illustrating an example of a protocol stack for the F1-C protocol. [Figure 9] FIG. 9 is a diagram illustrating an example of the configuration of an OAM (operation management device) according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of operation according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] A cellular communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0008] [First embodiment]

[0009] (Configuration of a cellular communication system) An example of the configuration of a cellular communication system according to an embodiment will be described. The cellular communication system 1 according to an embodiment is a 3GPP 5G system. Specifically, the radio access method in the cellular communication system 1 is NR (New Radio), which is a 5G radio access method. However, LTE (Long Term Evolution) may be applied at least partially to the cellular communication system 1. Furthermore, future cellular communication systems such as 6G may also be applied to the cellular communication system 1.

[0010] FIG. 1 is a diagram showing an example of the configuration of a cellular communication system 1 according to an embodiment.

[0011] 1, the cellular communication system 1 includes a 5G core network (5GC) 10, user equipment (UE) 100, base station devices (hereinafter sometimes referred to as "base stations") 200-1 and 200-2, and IAB nodes 300-1 and 300-2. The base station 200 may be referred to as a gNB.

[0012] In the following, an example in which base station 200 is an NR base station will be mainly described, but base station 200 may also be an LTE base station (i.e., an eNB).

[0013] In the following, the base stations 200-1 and 200-2 may be referred to as gNB 200 (or base station 200), and the IAB nodes 300-1 and 300-2 may be referred to as IAB nodes 300.

[0014] The 5GC 10 has an Access and Mobility Management Function (AMF) 11 and a User Plane Function (UPF) 12. The AMF 11 is a device that performs various mobility controls for the UE 100. The AMF 11 manages information about the area in which the UE 100 is located by communicating with the UE 100 using Non-Access Stratum (NAS) signaling. The UPF 12 is a device that performs transfer control of user data, etc.

[0015] Each gNB 200 is a fixed wireless communication node and manages one or more cells. A cell is used as a term indicating the smallest unit of a wireless communication area. A cell may also be used as a term indicating a function or resource for performing wireless communication with a UE 100. One cell belongs to one carrier frequency. In the following, there may be cases where a cell and a base station are used interchangeably.

[0016] Each gNB 200 is interconnected with the 5GC 10 via an interface called an NG interface. Figure 1 illustrates two gNBs, gNB 200-1 and gNB 200-2, connected to the 5GC 10.

[0017] Each gNB 200 may be divided into a central unit (CU) and distributed units (DU). The CU and DU are connected to each other via an interface called an F1 interface. The F1 protocol is a communication protocol between the CU and DU, and includes an F1-C protocol, which is a control plane protocol, and an F1-U protocol, which is a user plane protocol.

[0018] The cellular communication system 1 supports IAB, which enables wireless relay of NR access using NR for backhaul. The donor gNB 200-1 (or donor node, hereinafter sometimes referred to as the "donor node") is the terminal node of the NR backhaul on the network side and is a donor base station with additional functionality to support IAB. The backhaul can be multi-hop via multiple hops (i.e., multiple IAB nodes 300).

[0019] FIG. 1 illustrates an example in which IAB node 300-1 wirelessly connects with donor node 200-1, IAB node 300-2 wirelessly connects with IAB node 300-1, and the F1 protocol is transmitted over two backhaul hops.

[0020] The UE 100 is a mobile wireless communication device that performs wireless communication with a cell. The UE 100 may be any device that performs wireless communication with the gNB 200 or the IAB node 300. For example, the UE 100 may be a mobile phone terminal, a tablet terminal, a laptop computer, a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle, or an aircraft or a device provided in an aircraft. The UE 100 is wirelessly connected to the IAB node 300 or the gNB 200 via an access link. FIG. 1 shows an example in which the UE 100 is wirelessly connected to the IAB node 300-2. The UE 100 indirectly communicates with the donor node 200-1 via the IAB node 300-2 and the IAB node 300-1.

[0021] FIG. 2 is a diagram showing an example of the relationship between an IAB node 300, parent nodes, and child nodes.

[0022] As shown in FIG. 2, each IAB node 300 has an IAB-DU corresponding to a base station function unit and an IAB-MT (Mobile Termination) corresponding to a user equipment function unit.

[0023] An adjacent node (i.e., an upper node) on the NR Uu radio interface of the IAB-MT is called a parent node. The parent node is the DU of the parent IAB node or the donor node 200. The radio link between the IAB-MT and the parent node is called a backhaul link (BH link). FIG. 2 shows an example in which the parent nodes of the IAB node 300 are IAB nodes 300-P1 and 300-P2. The direction toward the parent node is called upstream. From the perspective of the UE 100, the upper node of the UE 100 may correspond to the parent node.

[0024] Adjacent nodes (i.e., lower nodes) on the NR access interface of the IAB-DU are called child nodes. The IAB-DU manages a cell, similar to the gNB 200. The IAB-DU terminates the NR Uu radio interface to the UE 100 and lower IAB nodes. The IAB-DU supports the F1 protocol to the CU of the donor node 200-1. While FIG. 2 shows an example in which the child nodes of the IAB node 300 are IAB nodes 300-C1 to 300-C3, the child nodes of the IAB node 300 may also include the UE 100. The direction toward the child nodes is called downstream.

[0025] Furthermore, all IAB nodes 300 connected to the donor node 200 via one or more hops form a directed acyclic graph (DAG) topology (hereinafter, sometimes referred to as "topology") with the donor node 200 as the root. In this topology, as shown in FIG. 2, adjacent nodes on the IAB-DU interface are child nodes, and adjacent nodes on the IAB-MT interface are parent nodes. The donor node 200 centrally manages, for example, resources, topology, and route management of the IAB topology. The donor node 200 is a gNB that provides network access to the UE 100 via a network of backhaul links and access links.

[0026] (Base station configuration) Next, a configuration of the gNB 200, which is a base station according to the embodiment, will be described. Fig. 3 is a diagram showing an example configuration of the gNB 200. As shown in Fig. 3, the gNB 200 has a radio communication unit 210, a network communication unit 220, and a control unit 230.

[0027] The wireless communication unit 210 performs wireless communication with the UE 100 and wireless communication with the IAB node 300. The wireless communication unit 210 has a receiving unit 211 and a transmitting unit 212. The receiving unit 211 performs various types of reception under the control of the control unit 230. The receiving unit 211 includes an antenna, and converts (down-converts) a wireless signal received by the antenna into a baseband signal (received signal), and outputs the signal to the control unit 230. The transmitting unit 212 performs various types of transmission under the control of the control unit 230. The transmitting unit 212 includes an antenna, and converts (up-converts) a baseband signal (transmitted signal) output by the control unit 230 into a wireless signal, and transmits the signal from the antenna.

[0028] The network communication unit 220 performs wired communication (or wireless communication) with the 5GC10 and wired communication (or wireless communication) with other adjacent gNBs 200. The network communication unit 220 has a receiving unit 221 and a transmitting unit 222. The receiving unit 221 performs various types of reception under the control of the control unit 230. The receiving unit 221 receives a signal from the outside and outputs the received signal to the control unit 230. The transmitting unit 222 performs various types of transmission under the control of the control unit 230. The transmitting unit 222 transmits the transmission signal output by the control unit 230 to the outside.

[0029] The control unit 230 performs various controls in the gNB 200. The control unit 230 includes at least one memory and at least one processor electrically connected to the memory. The memory stores programs executed by the processor and information used in processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation, encoding / decoding, etc. of baseband signals. The CPU executes programs stored in the memory to perform various processes. The processor performs processing of each layer, which will be described later. Note that the control unit 230 may perform each process or operation in the gNB 200 in each of the embodiments described below.

[0030] (Relay node configuration) Next, the configuration of the IAB node 300, which is a relay node (or relay node device; hereinafter, sometimes referred to as a "relay node") according to the embodiment, will be described. FIG. 4 is a diagram showing an example configuration of the IAB node 300. As shown in FIG. 4, the IAB node 300 has a wireless communication unit 310 and a control unit 320. The IAB node 300 may have multiple wireless communication units 310.

[0031] The wireless communication unit 310 performs wireless communication (BH link) with the gNB 200 and wireless communication (access link) with the UE 100. The wireless communication unit 310 for BH link communication and the wireless communication unit 310 for access link communication may be provided separately.

[0032] The wireless communication unit 310 has a receiving unit 311 and a transmitting unit 312. The receiving unit 311 performs various types of reception under the control of the control unit 320. The receiving unit 311 includes an antenna, and converts (down-converts) a radio signal received by the antenna into a baseband signal (received signal), and outputs the signal to the control unit 320. The transmitting unit 312 performs various types of transmission under the control of the control unit 320. The transmitting unit 312 includes an antenna, and converts (up-converts) a baseband signal (transmitted signal) output by the control unit 320 into a radio signal, and transmits the signal from the antenna.

[0033] The control unit 320 performs various controls in the IAB node 300. The control unit 320 includes at least one memory and at least one processor electrically connected to the memory. The memory stores programs executed by the processor and information used in processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processes. The processor performs processing of each layer, which will be described later. Note that the control unit 320 may perform each process or operation in the IAB node 300 in each of the embodiments described below.

[0034] (Configuration of user device) Next, a description will be given of a configuration of a UE 100 which is a user equipment according to the embodiment. Fig. 5 is a diagram showing an example of the configuration of the UE 100. As shown in Fig. 5, the UE 100 includes a radio communication unit 110 and a control unit 120.

[0035] The radio communication unit 110 performs radio communication in the access link, i.e., radio communication with the gNB 200 and radio communication with the IAB node 300. The radio communication unit 110 may also perform radio communication in the side link, i.e., radio communication with another UE 100. The radio communication unit 110 has a receiving unit 111 and a transmitting unit 112. The receiving unit 111 performs various receptions under the control of the control unit 120. The receiving unit 111 includes an antenna, and converts (down-converts) a radio signal received by the antenna into a baseband signal (received signal), and outputs the signal to the control unit 120. The transmitting unit 112 performs various transmissions under the control of the control unit 120. The transmitting unit 112 includes an antenna, and converts (up-converts) a baseband signal (transmitted signal) output by the control unit 120 into a radio signal, and transmits the signal from the antenna.

[0036] The control unit 120 performs various controls in the UE 100. The control unit 120 includes at least one memory and at least one processor electrically connected to the memory. The memory stores programs executed by the processor and information used in the processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processing. The processor performs processing of each layer, which will be described later. Note that the control unit 120 may perform each processing in the UE 100 in each of the embodiments described below.

[0037] (Protocol stack configuration) Next, a configuration of a protocol stack according to an embodiment will be described. Fig. 6 is a diagram showing an example of a protocol stack related to an RRC connection and a NAS connection of an IAB-MT.

[0038] As shown in FIG. 6, the IAB-MT of IAB node 300-2 has a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a non-access stratum (NAS) layer.

[0039] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of the IAB-MT of IAB node 300-2 and the PHY layer of the IAB-DU of IAB node 300-1 via a physical channel.

[0040] The MAC layer performs data priority control, retransmission processing using Hybrid ARQ (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of the IAB-MT in IAB node 300-2 and the MAC layer of the IAB-DU in IAB node 300-1 via a transport channel. The MAC layer of the IAB-DU includes a scheduler, which determines the transport format (transport block size, modulation and coding scheme (MCS)) and allocated resource blocks for the uplink and downlink.

[0041] The RLC layer transmits data to the RLC layer on the receiving side using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of the IAB-MT of IAB node 300-2 and the RLC layer of the IAB-DU of IAB node 300-1 via logical channels.

[0042] The PDCP layer performs header compression / decompression and encryption / decryption. Data and control information are transmitted between the PDCP layer of the IAB-MT of the IAB node 300-2 and the PDCP layer of the donor node 200 via a radio bearer.

[0043] The RRC layer controls logical channels, transport channels, and physical channels in response to the establishment, re-establishment, and release of radio bearers. RRC signaling for various settings is transmitted between the RRC layer of the IAB-MT of the IAB node 300-2 and the RRC layer of the donor node 200. When there is an RRC connection with the donor node 200, the IAB-MT is in an RRC connected state. When there is no RRC connection with the donor node 200, the IAB-MT is in an RRC idle state.

[0044] The NAS layer, which is positioned above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS layer of the IAB-MT of the IAB node 300-2 and the AMF 11.

[0045] Figure 7 is a diagram showing a protocol stack for the F1-U protocol. Figure 8 is a diagram showing a protocol stack for the F1-C protocol. Here, an example is shown in which the donor node 200 is divided into a CU and a DU.

[0046] As shown in Figure 7, the IAB-MT of IAB node 300-2, the IAB-DU of IAB node 300-1, the IAB-MT of IAB node 300-1, and the DU of donor node 200 each have a BAP (Backhaul Adaptation Protocol) layer above the RLC layer. The BAP layer is a layer that performs routing processing and bearer mapping / demapping processing. In the backhaul, the IP layer is transmitted via the BAP layer, enabling routing over multiple hops.

[0047] In each backhaul link, PDUs (Protocol Data Units) of the BAP layer are transmitted via a backhaul RLC channel (BH NR RLC channel). Configuring multiple backhaul RLC channels in each BH link enables traffic prioritization and QoS control. The association between BAP PDUs and backhaul RLC channels is performed by the BAP layer of each IAB node 300 and the BAP layer of the donor node 200.

[0048] As shown in FIG. 8, the protocol stack of the F1-C protocol has an F1AP layer and an SCTP layer instead of the GTP-U layer and UDP layer shown in FIG.

[0049] In the following, the processing or operations performed by the IAB-DU and IAB-MT of the IAB may be simply referred to as the processing or operations of the "IAB." For example, the transmission of a BAP layer message from the IAB-DU of IAB node 300-1 to the IAB-MT of IAB node 300-2 will be described as the IAB node 300-1 sending the message to IAB node 300-2. In addition, the processing or operations of the DU or CU of the donor node 200 may be simply referred to as the processing or operations of the "donor node."

[0050] Also, the upstream direction and the uplink (UL) direction may be used interchangeably, and the downstream direction and the downlink (DL) direction may be used interchangeably.

[0051] (Mobile IAB node) Currently, 3GPP has begun discussions toward the introduction of mobile IAB nodes. A mobile IAB node is, for example, an IAB node that is moving. A mobile IAB node may be an IAB node that is capable of moving. Alternatively, a mobile IAB node may be an IAB node that is currently stationary but is certain to move in the future (or is expected to move in the future).

[0052] The mobile IAB node enables, for example, a UE 100 under the mobile IAB node to receive services from the mobile IAB node while moving along with the movement of the mobile IAB node. For example, a case is envisioned in which a user (or UE 100) on a vehicle receives services via a mobile IAB node installed on the vehicle.

[0053] On the other hand, in contrast to mobile IAB nodes, there are also IAB nodes that do not move. Such IAB nodes may be referred to as intermediate IAB nodes. An intermediate IAB node is, for example, an IAB node that does not move. Alternatively, the intermediate IAB node may be a stationary IAB node. Alternatively, the intermediate IAB node may be an IAB node that remains stationary (or does not move) and remains installed at its installation location. Alternatively, the intermediate IAB node may be a stationary IAB node that does not move. The intermediate IAB node may be a fixed IAB node.

[0054] A mobile IAB node can also be connected to an intermediate IAB node. Also, a mobile IAB node can also be connected to a donor node 200. A mobile IAB node can also change its connection destination due to movement (migration or handover). The connection source may be an intermediate IAB node or the donor node 200. Also, the connection destination may be an intermediate IAB node or the donor node 200.

[0055] In the following, the terms "migration of a mobile IAB node" and "handover of a mobile IAB node" may be used interchangeably.

[0056] In the following description, a mobile IAB node may be referred to as a "mobile IAB node" or a "migrating IAB node." In either case, the mobile IAB node may be referred to as a "mobile IAB node."

[0057] Furthermore, in the following, the terms IAB node, mobile IAB node, and intermediate IAB node may be used interchangeably. An IAB node may be a mobile IAB node or an intermediate IAB node.

[0058] (Communication control method according to the first embodiment) In the first embodiment, authentication of the IAB node 300 will be described.

[0059] Authentication of the IAB node 300 is performed in a CN (Core Network) (or 5GC 10). That is, when the IAB node 300 establishes an RRC connection with the donor node 200, it transmits an RRC Setup Complete message (RRCSetupComplete) including an information element (iab-NodeIndication) indicating that the connection has been established by the IAB node to a CU (IAB-donor-CU) of the donor node 200. The CU of the donor node 200 selects an AMF 11 that can support the IAB node 300, and transmits an initial UE message (INITIAL UE MESSAGE) to the AMF 11. In response to receiving the initial UE message, the AMF 11 performs an authentication procedure for the IAB node 300. In this way, authentication of the IAB node 300 is performed in a CN (e.g., AMF 11).

[0060] Meanwhile, 3GPP is discussing authentication of network-controlled repeaters (NCRs) (for example, R2-2208890). NCRs are devices that control the amplification and forwarding of radio signals transmitted and received between UEs 100 and gNBs 200. Regarding NCRs, discussions are also being held on cases where authentication is performed in the CN, in the gNB 200, or in the Operations, Administration, and Maintenance (OAM) device.

[0061] Generally, when a network node such as an NCR or IAB node 300 is newly introduced into a network, configuration changes may be made on the CN side. Such configuration changes may affect the CN and require cost, effort, and time, which may be a burden on the operator who operates the CN.

[0062] Therefore, the first embodiment aims to be able to authenticate a network node without affecting the CN.

[0063] Therefore, in the first embodiment, first, a base station (e.g., donor node 200 or gNB 200) transmits a network node identifier assigned to a network node (e.g., IAB node 300) to an operation management device (e.g., OAM). Second, the network node transmits the network node identifier to the operation management device. Third, the operation management device authenticates the network node based on the network node identifier received from the base station and the network node identifier received from the network node.

[0064] In this way, since the authentication of the network node is performed by the OAM, not the CN, it is possible to authenticate the network node without affecting the CN. In this case, the OAM authenticates the network node based on the network node identifier received from the base station and the network node identifier received from the network node, so it is possible to easily authenticate the network node without performing complex processing.

[0065] The network node refers to a node that can be connected to the cellular communication system 1. The network node may be an IAB node 300 or an NCR. The network node may also be a reflector (RIS: Reconfigurable Intelligent Surfaces). The RIS is a node that controls the reflection and / or transmission of radio signals transmitted and received between the UE 100 and the gNB 200. In the first embodiment, the IAB node 300 will be mainly described as an example of a network node. Examples of the NCR and the RIS will be described in other examples.

[0066] (OAM configuration example) In the first embodiment, authentication of the IAB node 300 is performed in the OAM.

[0067] The OAM is an operation and management device that operates, maintains, and manages each node in the cellular communication system 1. The OAM may hold data or information for performing alternative coverage configuration for the gNB200 (or the donor node 200. Hereinafter, when there is no need to distinguish between the gNB200 and the donor node 200, it may be referred to as the gNB200). The OAM may hold software for realizing various functions in the gNB200, and may transmit (download) the software to the gNB200 in response to a request from the gNB200. The OAM may also hold log data acquired by each node in the cellular communication system 1.

[0068] Here, an example of the OAM configuration will be described.

[0069] 9 is a diagram illustrating an example of the configuration of the OAM 500 according to the first embodiment. As illustrated in FIG. 9, the OAM 500 includes a network communication unit 510 and a control unit 520.

[0070] The network communication unit 510 performs wired communication (or wireless communication) with the gNB200 (or donor node 200). The network communication unit 510 has a receiving unit 511 and a transmitting unit 512. The receiving unit 511 performs various receptions under the control of the control unit 520. The receiving unit 511 receives a signal transmitted from the gNB200 (or donor node 200) and outputs the received signal to the control unit 520. The transmitting unit 512 performs various transmissions under the control of the control unit 520. The transmitting unit 512 transmits a transmission signal output from the control unit 520 to the gNB200 (or donor node 200).

[0071] The control unit 520 performs various controls in the OAM 500. The control unit 520 includes at least one memory and at least one processor electrically connected to the memory. The memory stores programs executed by the processor and information used in processing by the processor. The processor may include a CPU. The CPU executes programs stored in the memory to perform various processes. The control unit 520 may perform each process or operation in the OAM 500 described below.

[0072] In addition, the gNB200 (or donor node 200) and the OAM500 may exchange messages (or signals) of a predetermined application layer, or may exchange messages (or signals) of a dedicated layer (e.g., the OAM layer).

[0073] (Operation example according to the first embodiment) Next, an example of operation according to the first embodiment will be described.

[0074] Fig. 10 is a diagram illustrating an example of operation according to the first embodiment. Note that in Fig. 10, the OAM 500 includes two OAMs: an IAB node OAM (IAB-node-OAM) 500-I and a donor OAM (IAB-donor-OAM) 500-D. The IAB node OAM 500-I is an OAM for the IAB node 300. The donor OAM 500-D is an OAM for the donor node 200. The IAB node OAM 500-I and the donor OAM 500-D are connected to the donor node 200. The IAB node OAM 500-I and the donor OAM 500-D may have the same configuration, which may be as shown in Fig. 9.

[0075] 10, in step S10, the donor node (IAB-donor) 200 logs in to the donor OAM 500-D. This allows the donor node 200, for example, to access the donor OAM 500-D as a trusted donor node. Note that the donor OAM 500-D may also log in to the donor node 200.

[0076] In step S11, the IAB-MT of the IAB node 300 executes a random access procedure with the CU of the donor node 200. At this time, the CU of the donor node 200 assigns a temporary C-RNTI to the IAB-MT of the IAB node 300 and transmits a Random Access Response (RAR) (Msg2) message including the temporary C-RNTI to the IAB-MT of the IAB node 300. When the IAB-MT of the IAB node 300 successfully receives an RRC Setup Request (Msg3) using the temporary C-RNTI, it promotes the temporary C-RNTI to a C-RNTI. The C-RNTI is used as an identifier to distinguish the IAB-MT of the IAB node 300 from other IAB-MTs. Specifically, the C-RNT is used to identify an RRC connection and receive scheduling information addressed to the IAB node 300 in the IAB-MT of the IAB node 300. The C-RNTI is an example of a network node identifier that identifies a network node (the IAB node 300 in the first embodiment).

[0077] In step S12, the donor node 200 transmits an INITIAL UE message to the AMF 11. In response to the RRC configuration complete message and the INITIAL UE message in step S11, a REGISTRATION REQUEST message (NAS message) is transmitted from the IAB node 300 to the AMF 11. The registration request message is a message requesting registration of the IAB node 300 in the network.

[0078] In step S13, when the AMF 11 approves the registration of the IAB node 300, it transmits an INITIAL CONTEXT SETUP REQUEST message including a REGISTRATION ACCEPT message (NAS message) to the donor node 200. The initial context setup request message is a message used to establish a UE context (IAB-MT context of the IAB node 300) in the donor node 200.

[0079] In step S14, the IAB-MT of the IAB node 300 and the CU of the donor node 200 execute an AS security mode command procedure to enable encryption (or decryption) of RRC messages. After the AS security mode command procedure is successful, the IAB-MT of the IAB node 300 and the CU of the donor node 200 execute a UE capability transfer procedure to transmit UE capability information of the IAB-MT of the IAB node 300 to the CU of the donor node 200. The CU of the donor node 200 then transmits an RRC reconfiguration message to the IAB-MT of the IAB node 300. The RRC reconfiguration message includes the registration accept message from the AMF 11 (step S13). At this time, the CU of the donor node 200 transmits the RRC reconfiguration message without including configuration information for the IAB node 300 (for example, configuration information of the BAP layer (BAP Configuration)).

[0080] In step S15, the donor node 200 transmits to the AMF 11 a response message (initial context setup response (INITIAL CONTEXT SETUP RESPONSE) message) in response to the initial context setup request message (step S13).

[0081] In step S16, the donor node 200 transmits the C-RNTI assigned to the IAB-MT of the IAB node 300 to the donor OAM 500-D. In reality, the donor node 200 assigns a temporary C-RNTI to the IAB-MT of the IAB node 300. However, since the temporary C-RNTI is promoted to a C-RNTI in the IAB-MT upon successful reception of an RRC setup (RRCSetup) message, it may be considered that the donor node 200 has assigned a C-RNTI to the IAB-MT. Note that the donor node 200 may transmit the C-RNTI to the donor OAM 500-D immediately after transmitting the RRC setup (RRCSetup) message (Msg4) in step S11. The donor node 200 may transmit the C-RNTI to the donor OAM 500-D using a predetermined message.

[0082] In step S17, a PDU session is established between the IAB-MT of the IAB node 300 and the AMF 11.

[0083] In step S18, the IAB-MT of the IAB node 300 logs in to the IAB node OAM 500-I. This allows the IAB-MT of the IAB node 300 to access the IAB node OAM 500-I as a trusted IAB-MT. The IAB node OAM 500-I may also log in to the IAB-MT of the IAB node 300.

[0084] In step S19, the IAB-MT of the IAB node 300 transmits the C-RNTI (step S11) assigned thereto and a cell global identifier (NCGI) to the IAB node OAM 500-I. The NCGI is a cell ID that can uniquely identify a cell even if the cell is in a mobile communication network of a different communication carrier. The NCGI is composed of a public land mobile network (PLMN) ID and an NR cell ID (NCI). The NCI is also composed of a gNB ID and a cell ID. The gNB ID included in the NCGI is used as a destination to which the donor OAM 500-D transmits the authentication result.

[0085] The IAB-MT of the IAB node 300 may transmit authentication additional information to the IAB node OAM 500-I together with the C-RNTI and NCGI. In the first embodiment, the C-RNTI is used when authenticating the IAB-MT of the IAB node 300, and the authentication additional information is information used to authenticate the IAB-MT together with the C-RNTI. The authentication additional information may be the International Mobile Subscriber Identity (IMSI) of the IAB-MT. Alternatively, the authentication additional information may be a vendor-specific ID. The vendor-specific ID may be the serial number of the IAB node 300 or a password.

[0086] The IAB-MT of the IAB node 300 may transmit the C-RNTI and NCGI (and additional authentication information) to the donor node 200 by using an RRC message. Also, the donor node 200 may transmit the C-RNTI and NCGI (and additional authentication information) to the IAB node OAM 500-I by using a predetermined message. The C-RNTI and NCGI (and additional authentication information) may be transmitted in an OAM container.

[0087] In step S20, the IAB node OAM 500-I transmits the received C-RNTI and NCGI (and additional authentication information) to the donor OAM 500-D in response to receiving the C-RNTI and NCGI (and additional authentication information) from the IAB node 300. The IAB node OAM 500-I may transmit the received C-RNTI and NCGI (and additional authentication information) to the donor OAM 500-D using a predetermined message.

[0088] In step S21, the donor OAM 500-D authenticates the IAB-MT of the IAB node 300 based on the C-RNTI received from the donor node 200 (step S16) and the C-RNTI received from the IAB node 300 (steps S19 and S20). Specifically, if the C-RNTI received from the donor node 200 matches the C-RNTI received from the IAB node 300, the donor OAM 500-D authenticates the IAB-MT (or determines that authentication is OK). On the other hand, if the C-RNTI received from the donor node 200 does not match the C-RNTI received from the IAB node 300, the donor OAM 500-D does not authenticate the IAB-MT (or determines that authentication is NG). When the donor OAM 500-D uses the IMSI of the IAB-MT as additional authentication information, the donor OAM 500-D may authenticate the IAB-MT by comparing (or verifying) the IMSI with the IMSI of the IAB-MT registered in advance in the donor OAM 500-D and determining whether they match.When the donor OAM 500-D uses the vendor-specific ID as additional authentication information, the donor OAM 500-D may also authenticate the IAB-MT by comparing (or verifying) the IMSI with the vendor-specific ID registered in advance and determining whether they match.

[0089] In step S22, the donor OAM 500-D transmits the authentication result to the donor node 200. The donor OAM 500-D can uniquely determine the donor node 200 as the destination of the authentication result based on the gNB ID included in the NCGI received in step S20. The donor OAM 500-D may transmit the NCGI together with the authentication result. The donor OAM 500-D may transmit the authentication result to the donor node 200 using a predetermined message. The following description will be given assuming that the donor OAM 500-D has authenticated the IAB-MT of the IAB node 300 as the authentication result.

[0090] In step S23, in response to receiving the authentication result indicating that the IAB-MT of the IAB node 300 has been authenticated, the donor node 200 performs configuration for the IAB-MT of the IAB node 300. Specifically, the CU of the donor node 200 transmits an RRC reconfiguration message including configuration information (BAP Configuration) of the BAP layer to the IAB-MT of the IAB node 300. The IAB-MT configures the configuration information in itself and communicates with the donor node 200.

[0091] (Another example 1 according to the first embodiment) In the first embodiment, the IAB node has been described as an example of a network node, but this is not limiting. The network node may also be the above-mentioned NCR. In this case, the network node identifier may also be the C-RNTI assigned to the NCR by the gNB 200.

[0092] 10 may represent an example of operation when the network node is an NCR. In this case, the IAB node 300 becomes the NCR, and the donor node 200 becomes the gNB 200. Also, the IAB node OAM 500-I becomes the NCR OAM, and the donor OAM 500-D becomes the gNB OAM.

[0093] As shown in Fig. 10, the gNB200 transmits the C-RNTI assigned to the NCR during the random access procedure to the gNB OAM (step S16). The NCR also transmits the C-RNTI and NCGI to the gNB OAM via the NCR OAM (steps S19 and S20). The gNB OAM can determine that the NCR is authenticated if the C-RNTI received from the gNB200 matches the C-RNTI received from the NCR, and that the NCR is not authenticated if the C-RNTI received from the gNB200 does not match the C-RNTI received from the NCR (step S21). The gNB OAM then transmits the authentication result to the gNB200 (step S22). When the gNB200 obtains an authentication result authenticating the NCR, it performs configuration on the NCR (step S23).

[0094] (Another example 2 according to the first embodiment) An example of the network node may be the RIS described above. In this case, the network node identifier may also be the C-RNTI assigned to the RIS by the gNB 200.

[0095] 10 may show an example of operation when the network node is an NCR. In this case, the IAB node 300 becomes the NCR, and the donor node 200 becomes the gNB 200. Also, the IAB node OAM 500-I becomes the RIS OAM, and the donor OAM 500-D becomes the gNB OAM.

[0096] As shown in FIG. 10, the gNB200 transmits the C-RNTI assigned to the RIS during the random access procedure to the gNB OAM (step S16). The RIS also transmits the C-RNTI and NCGI to the gNB OAM via the RIS OAM (steps S19 and S20). The gNB OAM can determine that the RIS is authenticated if the C-RNTI received from the gNB200 matches the C-RNTI received from the RIS, and that the RIS is not authenticated if the C-RNTI received from the NB200 does not match the C-RNTI received from the RSI (step S21). The gNB OAM then transmits the authentication result to the gNB200 (step S22). When the gNB200 obtains an authentication result that authenticates the RIS, it configures the RIS (step S23).

[0097] (Another example 3 according to the first embodiment) In the first embodiment, an example in which two OAMs, the IAB node OAM 500-I and the donor OAM 500-D, are used for OAM has been described, but a single OAM may be used. In this case, for example, in the operation example shown in FIG. 10 , the IAB node OAM 500-I may be eliminated and the donor OAM 500-D may be used as a single OAM 500, thereby implementing the same as in the first embodiment. In this case, the IAB node 300 may transmit the C-RNTI and the NCGI directly to the OAM 500 (steps S19 and S20). The example in which a single OAM is used is applicable to both the case in which the network node is an NCR (another example 1 according to the first embodiment) and the case in which the network node is a RIS (another example 2 according to the first embodiment).

[0098] [Other embodiments] A program may be provided that causes a computer to execute each process performed by the IAB node 300 or the gNB 200 (or the donor node 200). The program may be recorded on a computer-readable medium. Using the computer-readable medium, the program can be installed on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0099] In addition, circuits that perform each process performed by the IAB node 300 or gNB 200 (or donor node 200) may be integrated, and at least a portion of the IAB node 300 or gNB 200 (or donor node 200) may be configured as a semiconductor integrated circuit (chipset, SoC).

[0100] Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes can be made within the scope of the gist. Furthermore, the embodiments, operation examples, and processes can be appropriately combined within the scope of not being inconsistent.

[0101] (Addendum) (Appendix 1) A communication control method for use in a cellular communication system, comprising: a step of the base station transmitting a network node identifier assigned to the network node to an operation management device; the network node transmitting the network node identifier to the operation management device; and a step of the operation management device authenticating the network node based on the network node identifier received from the base station and the network node identifier received from the network node. Communication control method.

[0102] (Appendix 2) The step of performing authentication includes a step in which the operation management device determines to authenticate the network node if the network node identifier received from the base station matches the network node identifier received from the network node, and determines not to authenticate the network node if the network node identifier received from the base station does not match the network node identifier received from the network node. 10. The communication control method according to claim 1.

[0103] (Appendix 3) the step of transmitting by the network node includes a step of the network node transmitting the network node identifier and a cell global identifier to the operation management device; The operation management device further includes a step of transmitting an authentication result to the base station based on an identifier of the base station included in the cell global identifier. 10. The communication control method according to claim 1 or 2.

[0104] (Appendix 4) and, in response to receiving the authentication result authenticating the network node, the base station performs a configuration on the network node. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 3.

[0105] (Appendix 5) the step of transmitting the network node identifier and the cell global identifier to the operation management device includes a step of the network node transmitting authentication additional information together with the network node identifier and the cell global identifier to the operation management device; the determining step includes a step of making the determination based on the authentication additional information, The authentication additional information is a subscriber identifier or a vendor-specific identifier of the network node. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 4.

[0106] (Appendix 6) The network node is a relay node, the network node identifier is a C-RNTI, and the base station is a donor node. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 5.

[0107] (Appendix 7) The network node is a network controlled repeater (NCR) that controls amplification and transmission of radio signals, and the network node identifier is a C-RNTI. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 6.

[0108] (Appendix 8) The network node is a reflector (RIS) that controls reflection and / or transmission of a radio signal, and the network node identifier is a C-RNTI. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 7. [Explanation of symbols]

[0109] 1: Mobile communication system 10: 5GC 11 :AMF 100 :UE 110: Wireless communication unit 130: Control unit 200: Donor node (gNB) 210: Wireless communication unit 220: Network communication unit 230: Control unit 300: IAB node 310: wireless communication unit 320: Control unit 500: OAM 510: Network communication unit 520: Control unit

Claims

1. A communication control method for use in a cellular communication system, comprising: a step of the base station transmitting a network node identifier assigned to the network node to an operation management device; the network node transmitting the network node identifier to the operation management device; and a step of the operation management device authenticating the network node based on the network node identifier received from the base station and the network node identifier received from the network node. Communication control method.

2. The step of performing authentication includes a step in which the operation management device determines to authenticate the network node if the network node identifier received from the base station matches the network node identifier received from the network node, and determines not to authenticate the network node if the network node identifier received from the base station does not match the network node identifier received from the network node. The communication control method according to claim 1.

3. the step of transmitting by the network node includes a step of the network node transmitting the network node identifier and a cell global identifier to the operation management device; The operation management device further includes a step of transmitting an authentication result to the base station based on an identifier of the base station included in the cell global identifier. The communication control method according to claim 2.

4. and, in response to receiving the authentication result authenticating the network node, the base station performs a configuration on the network node. The communication control method according to claim 3.

5. the step of transmitting the network node identifier and the cell global identifier to the operation management device includes a step of the network node transmitting authentication additional information together with the network node identifier and the cell global identifier to the operation management device; the determining step includes a step of making the determination based on the authentication additional information, The authentication additional information is a subscriber identifier or a vendor-specific identifier of the network node. The communication control method according to claim 3.

6. The network node is a relay node, the network node identifier is a C-RNTI, and the base station is a donor node. The communication control method according to claim 1.

7. The network node is a network controlled repeater (NCR) that controls amplification and transmission of radio signals, and the network node identifier is a C-RNTI. The communication control method according to claim 1.

8. The network node is a reflector (RIS) that controls reflection and / or transmission of a radio signal, and the network node identifier is a C-RNTI. The communication control method according to claim 1.

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