Communication device, control method, and program

Abstract

To efficiently apply network slicing in a network configuration in the use of IAB.SOLUTION: A communication device operating as an IAB donor or an IAB node connected to a communication path formed by the IAB donor in a relay transmission network according to the provisions of Integrated Access and Backhaul (IAB) sends a message to set up a network slice to the IAB node connected to the communication path.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to communication control technology in a relay transmission system.

Background Art

[0002] In the 3rd Generation Partnership Project (3GPP (registered trademark)), cellular communication standards have been established. In the cellular communication standards in 3GPP (hereinafter referred to as "3GPP standards"), the standardization of Integrated Access and Backhaul (IAB) that integrates an access line and a backhaul line is in progress (see Patent Document 1). In IAB, the radio resources used for the access line between a base station and a user terminal (UE) are also used in the backhaul line. For example, in IAB, radio resources in a millimeter wave band such as the 28 GHz band can be used. By using IAB, a relay device (IAB node) can relay communication between a base station device (IAB donor) and a terminal device by a wireless line, and the area coverage can be expanded at a lower cost compared to the case of using a wired line such as an optical fiber.

[0003] Also, in the 3GPP standards, network slicing technology is adopted in which the network is virtually divided so that the required qualities such as bandwidth and delay suitable for each communication service are satisfied (see Patent Documents 2 and 3). In the 3GPP standards, eMBB, URLLC, and MIoT are defined as Slice / Service Type (SST). Here, eMBB is an abbreviation for enhanced Mobile BroadBand and indicates a service type with high speed and large capacity. Also, URLLC is an abbreviation for Ultra-Reliable and Low Latency Communications and indicates a service type with high reliability and low latency. Also, MIoT is an abbreviation for Massive Internet of Things and indicates a service type that establishes a large number of connections simultaneously.

Prior Art Documents

[0004] [Patent Document 1] Special Publication No. 2018-525874 [Patent Document 2] Special Publication No. 2020-511848 [Patent Document 3] Japanese Patent Publication No. 2018-160772 [Overview of the project] [Problems that the invention aims to solve]

[0005] When applying network slices to a network configuration using IAB, it is necessary to perform an operation to configure the slice corresponding to the service requested by the user terminal (UE) at each of the one or more IAB nodes included in the communication path to that UE.

[0006] This invention provides a method for efficiently applying network slices in a network configuration using IAB. [Means for solving the problem]

[0007] A communication device according to one aspect of the present invention is an IAB donor in a relay transmission network compliant with the provisions of Integrated Access and Backhaul (IAB). - A communication device that operates in the manner described above. A communication device The system has a transmission means for sending a message to an IAB node connected to a communication path to configure a network slice, and when a first IAB node is newly connected to the communication path and a network slice requested via the first IAB node is not configured in the communication path, the transmission means sends a message to the IAB node connected to the communication path to configure the requested network slice. [Effects of the Invention]

[0008] According to the present invention, network slices can be efficiently applied in a network configuration using IAB. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing an example configuration of a wireless communication system. [Figure 2] This figure shows an example of an IAB donor hardware configuration. [Figure 3] This figure shows an example of the functional configuration of an IAB donor. [Figure 4] This figure shows an example of information that associates communication paths with network slices. [Figure 5] This figure shows an example of the structure of information that can be included in a message being sent or received. [Figure 6] This figure shows an example of the processing flow performed by an IAB donor. [Figure 7] This diagram shows an example of the flow of communication processing performed in a wireless communication system. [Figure 8] This is a diagram showing an example configuration of a wireless communication system. [Figure 9] This figure shows an example of information that associates communication paths with network slices. [Figure 10] This diagram shows an example of the processing flow performed in a wireless communication system. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] (Embodiment 1) Figure 1 shows an example configuration of a wireless communication system according to this embodiment. The wireless communication system 100 in Figure 1 is configured to include a relay transmission network in accordance with the provisions of the Integrated Access and Backhaul (IAB) of the Third Generation Partnership Project (3GPP). In the IAB relay transmission network, wireless communication is performed with integrated access and backhaul lines. Hereinafter, this IAB relay transmission network will be referred to as the IAB network. The IAB network is configured to include IAB donors (e.g., IAB donors 102 and 107) and IAB nodes (e.g., IAB nodes 103-106 and 108-110). Through relay transmission via these IAB donors and IAB nodes, communication services are provided to terminals (e.g., terminal 111) staying in an area (e.g., area 112) provided by any node (IAB donor or IAB node). Note that the configuration in Figure 1 is merely an example, and more IAB donors, IAB nodes, and terminals can naturally exist.

[0012] An IAB donor establishes a connection by treating an IAB node as a terminal, and then performs configuration based on the Backhaul Adaptation Protocol (BAP). Once this configuration is complete, the IAB node functions as a relay device. An IAB donor can accommodate multiple IAB nodes. In the example in Figure 1, IAB donor 102 accommodates IAB nodes 103-106 and IAB node 110, and IAB donor 107 accommodates IAB nodes 108-109. Multiple IAB nodes can be connected in series, for example, with IAB node 109 connected downstream of IAB node 108. Alternatively, multiple IAB nodes can be connected in parallel to a common IAB donor (or IAB node), for example, with IAB nodes 102 and 104 connected downstream of IAB donor 102. An IAB donor is configured to connect to the core network (CN101) using, for example, a wired connection. The connection between an IAB donor and the core network may be made, for example, by an Internet Protocol (IP) network. In the following, communication between the IAB-based core network and each IAB node may be referred to as backhaul communication, to distinguish it from communication via access lines between an IAB donor or IAB node and a terminal. Also, in the following, among the nodes directly connected to a given IAB node in the communication path (IAB donor or IAB node), the node connected closer to the core network (upstream) may be referred to as the "parent node" of that IAB node. Conversely, among the IAB nodes directly connected to a given IAB node in the communication path, the node connected further away from the core network (downstream) may be referred to as a "child node".

[0013] In FIG. 1, for the IAB donor 102, the IAB nodes 103 and 104 are connected as its child nodes. Further, the IAB node 105 is connected to the IAB node 103 as its child node, and the IAB node 110 is connected to the IAB node 105 as its child node. Thus, they are connected in the order of the IAB donor 102, the IAB node 103, the IAB node 105, and the IAB node 110, and a communication path from the IAB donor 102 to the IAB node 110 is formed. Here, this communication path is referred to as "Path 1". Further, the IAB node 106 is connected to the IAB node 104 as its child node. Thereby, they are connected in the order of the IAB donor 102, the IAB node 104, and the IAB node 106, and a communication path from the IAB donor 102 to the IAB node 106 is formed. Here, this communication path is referred to as "Path 2". Further, the IAB node 108 is connected to the IAB donor 107, and the IAB node 109 is connected to the IAB node 108 as its child node. Thereby, they are connected in the order of the IAB donor 107, the IAB node 108, and the IAB node 109, and a communication path from the IAB donor 107 to the IAB node 109 is formed.

[0014] The terminal can be connected to the core network via the IAB donor or the IAB node. In FIG. 1, the terminal 111 is connected to the cell 112 provided by the IAB node 110 and is connected to the CN101 via the IAB node 110, the IAB node 105, the IAB node 103, and the IAB donor 102.

[0015] It is assumed that this wireless communication system is configured to be applicable to network slices. In this case, according to the communication services used by the terminal devices connected to the IAB node, not only the IAB node itself but also the IAB nodes on its upstream side need to set the corresponding network slices. For example, it is assumed that a communication service corresponding to Ultra-Reliable and Low Latency Communications (URLLC) is provided for the terminal 111 connected to the IAB node 110. In this case, not only the IAB node 110 but also the IAB nodes 103 and 105 need to set the network slices for URLLC. Also, for example, the same applies when a communication service corresponding to enhanced Mobile BroadBand (eMBB) is provided for the terminal 111 or other terminals. That is, not only the IAB node 110 but also the IAB nodes 103 and 105 need to set the network slices for eMBB. Thus, by setting the network slices in all of the IAB nodes that make up the communication path, it becomes possible to provide an appropriate communication environment for each service.

[0016] In IABs, for example, millimeter-wave radio resources such as the 28GHz band may be used, but millimeter-wave radio waves can be strongly attenuated by weather conditions. Also, due to the directivity of high-frequency radio waves such as millimeter waves, if there are obstacles in the propagation path, they may not be able to propagate around those obstacles and communication may not be maintained. For this reason, when millimeter-wave radio waves are used in a radio link established between an IAB donor and an IAB node, or between two IAB nodes, it is expected that a radio link failure (RLF) may occur, in which communication on that radio link may be temporarily interrupted. Such an RLF may be called a BH RLF to clarify that it is an RLF in a backhaul (BH) circuit. When a BH RLF occurs, the downstream IAB node in the section where the BH RLF occurred can search for and connect to another available IAB node and establish a new route to the IAB donor, thereby restoring backhaul communication. In addition, even in cases other than BH RLF, it is expected that an IAB node may need to change an already established route in response to a change in the communication quality with the parent node. Furthermore, the IAB framework enables topology redundancy, allowing IAB nodes to establish links for backhaul communication, for example, with multiple parent nodes. For instance, IAB node 110 can establish a connection with IAB node 106 while simultaneously establishing a connection with IAB node 105. In the following, unless otherwise specified, it is assumed that IAB node 110 is connected to path 1 but not to path 2.

[0017] It is possible that the network slice configured before the connection change at an IAB node may not be configured at the candidate IAB node that will be the new connection destination. For example, suppose IAB node 110, which is configured for URLLC and eMBB, switches its connection destination from IAB node 105 to another IAB node. Here, suppose IAB node 110 detects IAB node 106 as a candidate for the new connection destination among the surrounding nodes. In this case, the network slice for URLLC is not configured at IAB node 106, so it needs to be configured. Also, the network slice for URLLC needs to be configured at IAB node 104, which IAB node 106 is connected to. Alternatively, anticipating that IAB node 110 will connect, the network slice for URLLC can be configured individually at IAB node 106 and IAB node 104 in advance, for example, manually. However, if such configuration is performed, it would be necessary to configure each of the numerous IAB nodes individually, which is cumbersome. Furthermore, for example, when IAB node 110 connects to IAB node 106, it can configure the network slice for URLLC at IAB node 106 by making a predetermined request to IAB node 106. However, since the network slice for URLLC has not been configured at IAB node 104, IAB node 106 will send a network slice configuration request to IAB node 104. In this way, if the configuration is performed sequentially at each IAB node that makes up the route by tracing back the path, it is expected that a lot of time will be required to complete the configuration, which is inefficient.

[0018] In this embodiment, in view of these circumstances, the IAB donor manages the network slices that have been configured in each path and, in response to changes in the connection destination of the subordinate IAB nodes, collectively configures the network slices for the changed path. Here, "under the IAB donor" refers to the communication path managed by that IAB donor and the IAB nodes that constitute that communication path. In the example in Figure 1, the IAB nodes under IAB donor 102 are IAB nodes 103-106 and IAB node 110, and the IAB nodes under IAB donor 107 are IAB nodes 107-109. IAB donor 102, for example, maintains information on the network slices that have been configured in each of the paths, 1 and 2. Then, when IAB node 110 changes its connection destination to IAB node 106, IAB donor 102 ensures that the network slice configured in IAB node 110 is configured in the path from IAB node 106 to IAB donor 102. In the example shown in Figure 1, IAB donor 102 instructs not only IAB node 106 but also IAB node 104 to configure network slices for URLLC. This allows network slice configuration to be performed simultaneously for each IAB node along the path, enabling IAB node 110 to quickly execute communication using the appropriate network slice after switching the communication path.

[0019] The following describes an example configuration and processing flow for an IAB donor that performs such control processing. Note that some IAB nodes may have the functions of the IAB donor shown below. For example, if an IAB node with multiple child nodes connected in parallel has multiple paths formed through those child nodes, it may be configured to manage information about those multiple paths and configure network slices.

[0020] (Device configuration) Figure 2 shows an example of the hardware configuration of a communication device 201 that functions as an IAB donor according to this embodiment. While this description focuses on the case where the communication device 201 functions as an IAB donor, a communication device functioning as an IAB node may have a similar configuration. Furthermore, only a portion of an IAB node may have the configuration described below; that is, other IAB nodes may have different configurations. Also, the configuration shown in Figure 2 is merely an example, and the communication device 201 may be implemented with a hardware configuration different from that shown in Figure 2. For example, the communication device 201 may not have some of the hardware configurations shown in Figure 2, or it may include additional configurations.

[0021] The communication device 201, for example, has a hardware configuration that includes a control unit 202, a storage unit 203, a wireless communication unit 204, and an antenna control unit 205. The control unit 202 is configured to include one or more processors, such as a CPU or an MPU, and controls the entire device by executing a control program stored in the storage unit 203. CPU stands for Central Processing Unit, and MPU stands for Micro Processing Unit. The control unit 202 may also include one or more of the following: a field-programmable gate array (FPGA), a digital signal processor (DSP), or an application-specific integrated circuit (ASIC), configured to perform predetermined processing. The storage unit 203 is configured to include one or more memories, such as a read-only memory (ROM) or random access memory (RAM), or one or more storage devices, such as a hard disk drive (HDD) or a solid-state drive (SSD). The storage unit 203 stores various information, such as the control program executed by the control unit 202, and communication-related information including cell information, connected terminal information, and IAB routing information. The various operations described later are realized, for example, by the control unit 202 executing a control program stored in the memory unit 203. The wireless communication unit 204 includes a radio frequency (RF) chip and a baseband (BB) chip for performing wireless communication compliant with the 3GPP® Long-Term Evolution (LTE) standard and the fifth-generation (5G) cellular communication standard. The antenna control unit 205 controls the antenna for wireless communication performed by the wireless communication unit 204. Note that the antenna control unit 205 may be configured as separate hardware for antenna control only, or it may be configured as part of the BB chip or RF chip.

[0022] Figure 3 shows an example of the functional configuration 301 of the communication device 201. While this description focuses on the case where the communication device 201 functions as an IAB donor, a similar configuration may be found for a communication device functioning as an IAB node. Furthermore, only a portion of an IAB node may have the configuration described below; that is, other IAB nodes may have different configurations. Also, the configuration shown in Figure 3 is merely an example, and the communication device 201 may be implemented with a different functional configuration than the functional configuration 301 shown in Figure 3. For example, the communication device 201 may not have some of the functions shown in Figure 3, or it may include additional configurations.

[0023] The communication device 201 includes, for example, functions as a general base station device in a cellular communication system as part of its functional configuration 301. These functions include, for example, a signal transmission unit 302, a signal reception unit 303, a data storage unit 304, a connection control unit 305, an RRC control unit 306, and a broadcast signal generation unit 307. Furthermore, the functional configuration 301 of the communication device 201 includes functions related to network slicing. These network slicing functions include, for example, a network slice notification unit 308, a network slice collection unit 309, and a network slice allocation unit 310.

[0024] The signal receiving unit 302 and the signal transmitting unit 303 perform wireless communication with terminal devices in accordance with LTE and 5G cellular communication standards. The data storage unit 304 stores the software itself, IAB routing information, and information about the connected terminal. The data storage unit 304 can store, for example, a Public Land Mobile Network Identity (PLMN ID). The PLMN ID is an ID that identifies a telecommunications carrier, is set for the communication device 201 by the telecommunications carrier, and is stored by the data storage unit 304.

[0025] The connection control unit 305 performs connection control between terminals and core network functions. For example, the connection control unit 305 performs processing related to the connection and disconnection of terminals to and from the cellular network. As an example, the connection control unit 305 performs processing such as establishing synchronization with each terminal. The RRC control unit 306 performs connection control at the RRC layer, including sending and receiving radio resource control (RRC) messages with terminals and core network functions. For example, when a new IAB node connects, or when an IAB node switches its connection from under another IAB donor to its own, the RRC control unit 306 treats that IAB node as a terminal and establishes an RRC connection. In addition, when an IAB node changes the IAB donor that is the relay source for backhaul communication, or changes the destination IAB node, the RRC control unit 306 may send a message to terminals connected to that IAB node requesting the release of the RRC connection. The notification information generation unit 307 periodically transmits notification information containing system information and information for decoding that system information to the surrounding area for each cell provided by the communication device 201 itself. Other base station devices and terminals can receive the notification information, recognize the presence of a base station device in their vicinity, and perform connection processing to that base station device.

[0026] The network slice notification unit 308 and the network slice collection unit 309 perform processing to allow the IAB donor to share network slice information with its subordinate connections. For example, the network slice notification unit 308 notifies other IAB nodes or terminals connected to the subordinate IAB node of information about the network slices supported by the IAB donor, either directly or to other IAB nodes or terminals connected to the subordinate IAB node. The network slice collection unit 309 collects information about network slices supported or requested by other IAB nodes or terminals, either directly connected or connected to the subordinate IAB node. The network slice allocation unit 310 allows the IAB donor to allocate network slices to other IAB nodes. Alternatively, an IAB node may notify other subordinate IAB nodes or terminals of information about the network slices it supports and collect information about network slices requested by those other IAB nodes or terminals.

[0027] An IAB donor (or possibly an IAB node) stores information relating the communication paths it manages to the network slices configured along those paths. For example, IAB donor 102 may store information indicating that network slices for eMBB and URLLC have been configured as information about path 1. Figure 4 shows an example of network slice information configured for each path based on requests from subordinate IAB nodes, managed by an IAB donor (or possibly an IAB node). IAB donor 102 stores information indicating that IAB nodes 103, 105, and 110, which are included in path 1, have been configured with network slices for eMBB and URLLC, as shown in information 401. IAB donor 102 also stores information indicating that IAB nodes 104 and 106, which are included in path 2, have been configured with network slices for eMBB.

[0028] Here, suppose IAB node 110, which has network slices configured for eMBB and URLLC, requests a new connection from IAB node 106. In this case, IAB donor 102 identifies, based on information 401, that IAB nodes 104 and 106 on route 2 have configured network slices for eMBB but not for URLLC. IAB donor 102 assigns network slices for URLLC to IAB nodes 104 and 106 so that IAB node 110 can continue communication based on network slices for eMBB and URLLC. Then, after network slices for URLLC are assigned to IAB nodes 104 and 106, IAB node 110 establishes a connection with IAB node 106. After performing this procedure, IAB donor 102 stores information, as in information 402, indicating that network slices for eMBB and URLLC have been configured on route 2 to which IAB node 110 is newly connected. Furthermore, IAB donor 102 may, for example, disconnect IAB node 110 from route 1, and in that case, update the network slice assignments at IAB nodes 103 and 105 that remain on route 1. IAB donor 102 may, for example, release the network slice configuration for URLLC at IAB nodes 103 and 105 if only eMBB is requested and URLLC is not required.

[0029] Figure 5(A) shows the format of Single-Network Slice Selection Assistance Information (S-NSSAI) used when notifying network slice information. The format in Figure 5(A) is used, for example, when an IAB donor or IAB node notifies information about the network slices it supports, or when an IAB node or a terminal connected to that IAB node notifies information about the network slices it requests. The format in Figure 5(A) includes Slice Service Type (SST) and Slice Differentiator (SD). SST is set with information about eMBB, URLLC, or mMTC as the classification of the network slice, and SD is set with optional information that further subdivides the network slice indicated by SST. In addition to eMBB, URLLC, and mMTC, if further classifications of network slices are defined in SST, information indicating those further classifications may also be set. An IAB node sends a message to an IAB donor with values ​​set in SSD and SD indicating the network slices it requests to use or the network slices it supports. Furthermore, an IAB donor may send a message to its subordinate IAB donors with values ​​set in SSD and SD that indicate the network slices it supports. It should be noted that NSSAI messages containing multiple S-NSSAIs may be sent and received between an IAB donor and an IAB node.

[0030] Figure 5(B) shows the S-NSSAI format used when an IAB donor (or IAB node) allocates or releases a network slice to its subordinate IAB nodes. The format in Figure 5(B) includes SST and SD, as well as Slice Allocate, which indicates the setting value "ON" when allocating a network slice and "OFF" when releasing a network slice. In one example, a Slice Allocate value of 1 may indicate "ON," and a Slice Allocate value of 0 may indicate "OFF." The IAB donor (or IAB node) sends a message to its subordinate IAB nodes with values ​​set in SST and SD indicating the network slice requested by the IAB node or connected terminal, and with Slice Allocate set to "1." The IAB donor (or IAB node) may also send a message with Slice Allocate set to "0" based on the fact that a connected terminal has been disconnected or that a subordinate IAB node has moved under the control of another IAB donor. In this case, the SST and SD values ​​may be set to indicate the network slice configured in response to a request from the IAB node or terminal. This message may also be sent to each IAB node that makes up the path, including the IAB node to which the disconnected terminal was connected and the IAB node that has moved under another IAB donor.

[0031] (Process flow) Next, using Figure 6, we will explain an example of the processing flow performed by an IAB donor (or IAB node). This processing is performed when another IAB node connects to any of the IAB nodes that make up the communication path under the IAB donor (or IAB node). This processing can be achieved, for example, by the control unit 202 executing a program stored in the storage unit 203. In the following explanation, we will focus on the IAB donor 102.

[0032] First, the IAB donor 102 detects a connection request from IAB node 110 to another connectable IAB node 106 (S601). For example, when IAB node 110 measures the surrounding wireless environment and identifies a connectable IAB node 106, it sends a connection request to that IAB node 106. At this time, the connection request consists of an S-NSSAI as shown in Figure 5(A). Note that the connection request here includes an S-NSSAI with URLLC set in SST and an S-NSSAI with eMMB set in SST. This allows the IAB donor 102 to identify the network slice requested by IAB node 110. Based on information 401, the IAB donor 102 determines whether all the network slices requested by IAB node 110, identified in S601, are configured in route 2, which includes the IAB node 106 to which IAB node 110 is requesting connection (S602). For example, IAB donor 102, by referring to information 401, identifies that a network slice for eMMB is configured in route 2, which includes IAB node 106. IAB donor 102 may then identify that a network slice for URLLC, which is requested by IAB node 110, is not configured (YES in S602). In this case, IAB donor 102 notifies IAB nodes 104 and 106, which are included in route 2, of the allocation of a network slice for URLLC (S603). For example, IAB donor 102 sends a message to IAB nodes 104 and 106 in the format shown in Figure 5(B), with Slice Allocate turned ON and SST set to URLLC. IAB nodes 104 and 106 configure the network slice for URLLC upon receiving this message. Then, IAB donor 102 ensures that the connection between IAB node 110 and IAB node 106 is completed after the network slice configuration is finished at IAB node 104 and IAB node 106 (S604).This is just one example; IAB donor 102 may configure the network slices in parallel with establishing the connection to IAB node 110, or after establishing the connection to IAB node 110. Furthermore, if IAB donor 102 determines that all the network slices requested by IAB node 110 are already configured (NO in S602), it may establish a connection to IAB node 110 without configuring any new network slices (S604).

[0033] In this way, the IAB donor 102 can efficiently configure network slices for other IAB nodes on the communication path to which the IAB node is connected, based on the network slices requested by the IAB nodes connected to it. For example, if only other IAB nodes that have not yet configured the network slice requested by the target IAB node exist around the target IAB node, the IAB donor will configure the network slice for the communication path that includes those other IAB nodes. In particular, the network slice can be configured simultaneously for each IAB node included in the communication path under the control of the IAB donor. This makes it possible to quickly execute communication suitable for the network slice requested by the target IAB node after the connection is established at that IAB node.

[0034] Figure 7 shows an example of the processing flow performed in a wireless communication system. Here, we will focus on IAB donor 102 and its subordinate IAB nodes 103-106 and 110, and will not mention IAB donor 107 and its subordinate IAB nodes. Here, we will explain the operation when IAB donor 102 assigns network slices to IAB nodes 104 and 106 when IAB node 110, which was connected to IAB node 105, switches its connection destination to IAB node 106.

[0035] First, under the control of IAB donor 102, settings are performed for each of the following paths: Path 1, which includes IAB nodes 103, 105, and 110, and Path 2, which includes IAB nodes 104 and 106 (S701). For example, IAB donor 102 receives an NSSAI from IAB node 103 that includes S-NSSAI indicating eMBB and URLLC respectively, and configures network slices for eMBB and URLLC for IAB node 103. Similarly, IAB donor 102 configures network slices for eMBB and URLLC for IAB node 105, which is connected to IAB node 103, and for IAB node 110, which is connected to IAB node 105. Note that Figure 7 shows an example where network slices for eMBB and URLLC are configured for IAB node 103 and IAB node 105 from the time of connection, but is not limited to this. For example, IAB nodes 103 and 105 may configure network slices for either eMBB or URLLC only, based on the services requested by terminals connecting to them. Subsequently, in response to IAB node 110 requesting to connect to IAB node 105, network slices for the unconfigured eMBB or URLLC may be configured for IAB nodes 103 and 105. Through this operation, network slices for both eMBB and URLLC are configured at each IAB node of route 1. On the other hand, at IAB nodes 104 and 106 forming route 2, network slices for eMBB only may be configured in the same manner as described above.

[0036] Subsequently, IAB node 110 changes its connection destination to IAB node 106 due to changes in the wireless environment or movement of its own device. At this time, IAB node 110 sends an NSSAI containing S-NSSAI corresponding to eMBB and URLLC to IAB node 106 (S702). IAB node 106 forwards this NSSAI to IAB donor 102 via IAB node 104. Note that this is just an example, and IAB node 110 may, for example, send information indicating that IAB node 106 is the connection destination via path 1, which has a connection established at that time, along with the NSSAI. Also, the network slice requested by IAB node 110 is already known to IAB donor 102 in S701. For this reason, IAB node 110 may notify IAB donor 102 only of connection requests that designate IAB node 106 as the connection destination.

[0037] Based on the connection request, IAB donor 102 detects that no network slices for URLLC have been configured at IAB nodes 104 and 106. IAB donor 102 then turns on Slice Allocate and sends a message to IAB nodes 104 and 106 as shown in Figure 5(B), with SST set to URLLC (S703, S704). This results in the simultaneous allocation of network slices for URLLC to IAB nodes 104 and 106. Subsequently, IAB node 110 establishes synchronization of the downlink based on the synchronization signal from IAB node 106, and also establishes synchronization of the uplink through Random Access Channel (RACH) processing (S705). IAB node 110 then establishes an RRC connection with IAB node 106 (and with IAB donor 102 via IAB node 106) (S706). Subsequently, IAB donor 102 updates its connection information, including route information with the IAB nodes connected to it, to establish a route between IAB donor 102 and IAB node 110. This allows the IAB donor 102 to provide a service-appropriate communication environment to the terminal using the necessary network slice settings immediately after the IAB node 110 connects.

[0038] (Embodiment 2) Figure 8 shows an overview of the operation of the wireless communication system 800 according to this embodiment. In the wireless communication system 800, under the IAB donor 802, there is a route 1 including IAB nodes 803 and 805, and a route 2 including IAB nodes 804, 806, and 810. Network slices for eMBB are configured in both route 1 and route 2. In this case, as shown in information 901 in Figure 9, the IAB donor 802 holds information indicating the IAB nodes included in each route, and information indicating the network slices configured (corresponding) in those routes. Furthermore, under the IAB donor 807, there is a route including IAB nodes 808 and 809, and network slices for eMBB are configured there. The IAB donor 807 also holds information (not shown) similar to information 901.

[0039] In this state, terminal 811, located within cell 812 provided by IAB node 810 and connected to IAB node 810, requests IAB node 810 to perform URLLC communication. For example, an unconnected terminal 811 sends a connection request for URLLC communication to IAB node 810. Alternatively, terminal 811 connected to IAB node 810 may send a message requesting URLLC communication to IAB node 810 in response to the launch of a new application, etc. At this time, IAB node 810 requests IAB donor 802 to configure a network slice for URLLC. Here, IAB donor 802 determines whether it is possible to configure a network slice for URLLC in the communication path under it, and if it is possible, it configures the network slice as in Embodiment 1.

[0040] On the other hand, if IAB donor 802 determines that it cannot configure a network slice for URLLC in any of its subordinate communication paths, it determines whether it can connect via another IAB donor that has an IAB node that IAB node 810 can connect to. For example, IAB donor 802 obtains measurement results of broadcast signals and reference signals from other surrounding IAB nodes at IAB node 810 and identifies other IAB nodes under other IAB donors as candidate IAB nodes for switching the connection. Then, IAB donor 802 determines whether that candidate IAB node for switching the connection can configure a network slice for URLLC. For example, IAB node 810 may refer to broadcast signals from other surrounding IAB nodes to identify the network slice that the other IAB node can handle and notify IAB donor 802 of the result of that identification. In one example, IAB donor 802 may extract IAB nodes capable of handling the network slice for URLLC and identify those IAB nodes as candidates for switching the connection of IAB node 810. Alternatively, IAB node 810 may send measurement results and other information to IAB donor 802 only for other IAB nodes capable of handling the network slice requested by its device. Furthermore, when IAB donor 802 obtains information on candidate IAB nodes for switching the connection from IAB node 810, it may inquire with the IAB donor that has that IAB node whether it is capable of handling the network slice for URLLC.

[0041] Here, we assume that IAB donor 807 is capable of handling the network slice for URLLC, and that IAB node 808 has been identified as a candidate for switching the connection of IAB node 810. In this case, IAB donor 802 decides to switch (hand over) the connection destination of IAB node 810 from IAB node 806 to IAB node 808. At this time, IAB donor 802 notifies IAB donor 807 of information about IAB node 810, that a network slice for URLLC is requested, and information indicating IAB node 808 as the candidate for switching the connection destination. Based on this notification, IAB donor 807 notifies IAB node 808 of the allocation of the network slice for URLLC. As a result, the network slice for URLLC is set up in the communication path from IAB donor 807 to IAB node 808. Subsequently, IAB node 110 establishes a connection with IAB node 808.

[0042] After this connection switching process, for example, IAB donor 802 will hold information such as the information for route 1 and route 2 in information 902 in Figure 9, where IAB node 810 has been excluded from route 2. Here, since no network slice configuration for URLLC was performed for routes 1 and 2, the corresponding network slice information remains unchanged. On the other hand, IAB donor 807 will newly hold information about the route obtained when IAB node 810 connects to IAB node 808, as shown in the information for route 3 in information 902. Note that in this route 3, since a network slice configuration for URLLC was performed, URLLC is included in the corresponding network slice. As mentioned above, information 902 in Figure 9 may be held by IAB donor 802 and IAB donor 807, respectively, regarding the communication paths under them, but in one example, both IAB donor 802 and IAB donor 807 may hold all of information 902. In other words, IAB donor 802 may hold not only information about the communication paths it manages, but also information about communication paths managed by other surrounding IAB donors.

[0043] Next, using Figure 10, an example of the processing flow performed in a wireless communication system will be explained. In the following, as described above, it will be assumed that IAB node 810 is connected to IAB node 806 under IAB node 802, and that a network slice for URLLC cannot be configured in its current state. Furthermore, the following processing is achieved by the control unit 202 of the IAB donor or IAB node that is the main operator of each process executing a program stored in the memory unit 203.

[0044] In this process, first, IAB node 810 requests the connected IAB donor 802 to configure a network slice for URLLC (S1001). For example, IAB node 810 may send a message containing an S-NSSAI with URLLC configured in the format of SST in Figure 5(A) to the connected IAB node 806 and then send it to the IAB donor 802. Alternatively, the request for configuring a network slice for URLLC may be made, for example, by forwarding a message requesting a network slice for URLLC, sent from terminal 812 to IAB node 810, to the IAB donor 802. In other words, the IAB donor 802 may be notified that a network slice for URLLC should be configured to IAB node 810 without any special determination processing at IAB node 810. Note that IAB node 810 may also request a network slice for URLLC when it requests an initial connection from IAB donor 802. In this case, IAB node 810 may send a connection request to the surrounding IAB node 805 or IAB node 806, which includes a request for a network slice for URLLC. When IAB node 805 or IAB node 806 receives the connection request, it forwards it to IAB donor 802.

[0045] IAB donor 802 determines whether the network slice requested by IAB node 810 is configured in the communication path that includes the IAB node to which IAB node 810 is connected (S1002). If such a network slice is already configured (YES in S1002), IAB donor 802 establishes the connection between IAB node 806 and IAB node 810 if the connection has not yet been established (S1005). IAB donor 802 also configures the network slice for IAB node 810 and completes the process. On the other hand, if such a network slice is not yet configured (NO in S1002), IAB donor 802 determines whether the requested network slice can be configured in the communication path under its control (S1003). That is, for example, if IAB donor 802 receives a request from IAB node 810 connected to IAB node 806, it determines whether a network slice for URLLC can be allocated in path 2 that includes IAB node 806. Furthermore, if IAB donor 802 determines that it is not possible to allocate a network slice for URLLC on route 2, it may determine whether it is possible to allocate it on another route under its own device that IAB node 810 can connect to. If IAB donor 802 determines that it is possible to allocate the requested network slice on a route under its own device that IAB node 810 can connect to (YES in S1003), it executes the allocation of that network slice (S1004). Then, IAB node 810 connects to the IAB node on the route where the network slice was allocated (S1005). Note that if IAB node 810 can configure the network slice without changing the connection destination, the process in S1005 may be omitted.

[0046] If IAB donor 802 determines that it cannot allocate the requested network slice on a path under its own device that IAB node 810 can connect to (NO in S1003), it proceeds to S1006. In S1006, IAB donor 802 obtains information about IAB nodes under other IAB donors (e.g., IAB donor 807) that IAB node 810 can connect to. Note that IAB nodes that IAB node 810 can connect to are, for example, IAB nodes that send broadcast signals at a power level that IAB node 810 can receive. IAB donor 802 can obtain this information, for example, from IAB node 810, such as notification of the measurement results of the broadcast signal by IAB node 810. Note that IAB donor 802 can also have in advance information about nodes that provide adjacent cells from other IAB donors that have IAB nodes under their control that form adjacent cells to cells provided by IAB nodes under its own device. Then, IAB donor 802 can specify to IAB node 810 that an IAB node under that other IAB donor is the cell to be measured. In this case, IAB node 810 can notify IAB donor 802 of the identification information and radio quality measurement results associated with at least some of the specified IAB nodes. IAB donor 802 can, for example, obtain information in advance from another IAB donor about IAB nodes under that other IAB donor that are capable of allocating a network slice for URLLC. This allows IAB donor 802 to determine whether there are IAB nodes around IAB node 810 that are capable of handling a network slice for URLLC. Here, it is assumed that IAB donor 802 has determined that IAB node 808 under IAB donor 807 is capable of handling a network slice for URLLC and is an IAB node that can connect to IAB node 810.

[0047] IAB donor 802 transmits information about IAB node 810, information about the network slice requested by IAB node 810, and information about IAB node 808 to IAB donor 807, which manages IAB node 808 (S1007). In other words, the IAB donor notifies other IAB donors that manage the other IAB nodes to which it will connect, providing information that identifies the IAB nodes under its control, information about other IAB nodes to which that IAB node should connect, and information about the requested network slice. Then, IAB donor 807 notifies IAB node 808, to which IAB node 810 will connect, of the assignment of the requested network slice (S1008), and the network slice is configured at IAB node 808. Then, IAB node 810 connects to the IAB node on the path to which the network slice was assigned (S1005).

[0048] In this embodiment, the network slice information requested by IAB node 810 may be information indicating URLLC and eMMB, but it may also be information indicating only URLLC. That is, in one example, IAB donor 802 may connect IAB node 810 to IAB node 808 in order to allocate a network slice for URLLC while maintaining route 2 corresponding to eMMB with IAB node 810. Alternatively, if URLLC and eMMB are indicated as the network slice information requested by IAB node 810, IAB donor 807 may configure network slices for both URLLC and eMMB on the route to IAB node 808.

[0049] In the example above, IAB donor 802 described a case where the IAB nodes under its control are either able to configure network slices or are not able to configure them in common. However, it is not limited to this case. For example, in Figure 8, it is possible that URLLC cannot be configured on route 2, to which IAB node 810 is connected, but URLLC can be configured on route 1. In this case, IAB donor 802 may configure IAB node 810 to connect to route 1, which is under its control. In other words, IAB donor 802 does not need to switch the connection destination across IAB donors. IAB donor 802 may decide to connect IAB node 810 to an IAB node (or route) that is connectable to IAB node 810 and capable of configuring the required network slice. If the destination IAB node (or route) is not under its control, IAB donor 802 may notify the IAB donor managing the destination IAB node of the information as described above and have them configure the network slice. Furthermore, if IAB donor 802 determines that there are no IAB nodes (or routes) that IAB node 810 can connect to and that can configure the required network slice, it may reject IAB node 810's request to configure the network slice.

[0050] In the embodiments described above, examples were given in which an IAB node establishes a connection after the network slice has been configured. However, if the network slice has not been configured after the connection has been established, the configuration may be performed as described above. Furthermore, if it is not possible to configure the network slice in the communication path during the connection, a process to change the connection destination may be performed as in Embodiment 2. In addition, when an IAB node requests a new connection, the network slice required by that IAB node may be configured in advance. That is, the network slices that are expected to be configured for a terminal may be identified in advance, and the network slice that an IAB node should request may be identified when an IAB node that does not belong to any IAB donor makes an initial connection. In this case, for example, a separate random access procedure resource corresponding to each network slice may be prepared, and the network slice requested by the IAB node may be identified by the IAB donor depending on which resource is used.

[0051] Furthermore, while the embodiments described above illustrate examples in which an IAB donor assigns network slices to its subordinate IAB nodes, the invention is not limited to these examples. For instance, an IAB node newly connecting or changing its connection destination (IAB node 110 or IAB node 810) may notify the destination IAB node that it should assign a network slice using a message in the format shown in Figure 5(B). In this case, the destination IAB node, upon receiving a message with Slice Allocation set to ON in the format shown in Figure 5(B), sets the network slice and then forwards the message to its parent node. The parent node then similarly sets the network slice. By repeating this process, network slices can be set along the path to the IAB donor. In other words, an IAB node newly connecting or changing its connection destination (IAB node 110 or IAB node 810) may send a message to cause IAB nodes along the path to the IAB donor to set the network slice. Furthermore, when an IAB node that is newly connecting or changing its connection destination (IAB node 110 or IAB node 810) sends an NSSAI to an IAB donor, IAB nodes along the relay path to that IAB donor may obtain that NSSAI. In addition, if the requested network slice has not been configured, the IAB nodes along the relay path to the IAB donor may autonomously configure that network slice without waiting for instructions from the IAB donor.

[0052] Furthermore, the network slice configuration according to the above embodiment may be performed only for a predetermined network slice. That is, when an IAB node requests the configuration of a predetermined network slice based on a new connection, a change of connection destination, or a request from a terminal, the IAB node may cause the IAB nodes on the path to which it connects to configure that network slice. On the other hand, when an IAB node requests the configuration of a network slice other than the predetermined network slice, the IAB node may be prevented from causing the IAB nodes on the path to which it connects to configure that network slice. In this case, if there is no path where that network slice is configured, the network slice configuration requested by the IAB node may be rejected. Conversely, when an IAB node requests the configuration of a predetermined network slice, the IAB node may be prevented from causing the IAB nodes on the path to which it connects to configure that network slice. In this case, when an IAB node requests the configuration of a network slice other than the predetermined network slice, the IAB node may cause the IAB nodes on the path to which it connects to configure that network slice. Here, the predetermined network slice may be, for example, eMMB, URLLC, MIoT, or C-V2X for which the SST value is currently defined. Here, C-V2X refers to Cellular Vehicle to Everything. Note that these are just examples, and some pre-configured network slices may be treated as designated network slices. This allows, for example, high-priority network slices to be configured automatically, while other network slices require configuration by the telecommunications carrier.

[0053] Furthermore, a predetermined validity period may be set for the network slice configured as described above. In this case, for example, the predetermined validity period may be stored in a message that includes information as shown in Figure 5(B) and notified to each IAB node. This prevents configured network slices from being unnecessarily maintained, making it possible to secure wireless and computing resources for configuring new network slices.

[0054] As described above, in this embodiment, an IAB donor or IAB node identifies whether a requested network slice is not set in the communication path between the IAB donor and an IAB node that is newly establishing a connection or changing its connection destination. If an unset network slice exists, it instructs other IAB nodes on that path to set that network slice. In other words, the communication device operating as an IAB donor or IAB node in this embodiment identifies the lack of network slice settings requested by an IAB node newly connected to the communication path and automatically instructs other IAB nodes on the path to set that network slice. This makes it possible to flexibly set and change communication paths in an IAB relay transmission system while automatically and appropriately setting the required network slice. Therefore, network slices can be efficiently applied in a network configuration using IAB.

[0055] (Summary of the embodiments) At least some of the embodiments described above can be summarized as follows:

[0056] (Item 1) A communication device that operates as an IAB donor or an IAB node connected to a communication path formed by an Integrated Access and Backhaul (IAB) in a relay transmission network compliant with the provisions of the Integrated Access and Backhaul (IAB), A communication device characterized by having a transmission means for sending a message to an IAB node connected to the aforementioned communication path to configure a network slice.

[0057] (Item 2) The communication device according to item 1, characterized in that the communication device is the IAB donor that forms the communication path.

[0058] (Item 3) The communication device according to item 1, characterized in that the transmitting means transmits a message to the second IAB node to set the requested network slice when a first IAB node is connected to the communication path and the network slice requested by the first IAB node is not set at a second IAB node included in the communication path.

[0059] (Item 4) An acquisition means for acquiring first information indicating the requested network slice from the first IAB node, A storage means for holding second information indicating the network slice configured by the second IAB node, A determination means for determining whether the requested network slice is configured at the second IAB node based on the first information and the second information, The communication device according to item 3, further characterized by having the following:

[0060] (Item 5) The communication device according to item 4, wherein the acquisition means further acquires the second information from the second IAB node.

[0061] (Item 6) The communication device according to item 4 or 5, characterized in that the acquisition means acquires the first information from the connection request by the first IAB node.

[0062] (Item 7) The communication device according to any one of items 4 to 6, characterized in that the acquisition means acquires the first information when the first IAB node switches its connection destination from a third IAB node belonging to another communication path formed by the IAB donor to the second IAB node belonging to the communication path.

[0063] (Item 8) The communication device according to any one of items 4 to 7, characterized in that the acquisition means acquires the first information relating to a network slice when a terminal is connected to the first IAB node and the terminal requests communication for a network slice not configured in the first IAB node.

[0064] (Item 9) The communication device according to any one of items 4 to 8, further comprising a means for specifying a path that includes IAB nodes to which the first IAB node can connect, which is capable of configuring the required network slice indicated by the first information, and which further specifies the communication path to which the first IAB node should connect.

[0065] (Item 10) The communication device according to item 9, further comprising means for connecting the first IAB node to an IAB node that can be connected to the first IAB node, which is included in the communication path identified by the identifying means.

[0066] (Item 11) The communication device according to item 9 or 10, further comprising notification means for notifying the other IAB donor of information indicating the first IAB node, information indicating the requested network slice indicated by the first information, and information indicating the IAB node to which the first IAB node can connect, when an IAB node to which the first IAB node can connect, which is included in the communication path identified by the identification means, belongs to another IAB donor different from the IAB donor.

[0067] (Item 12) The communication device according to any one of items 9 to 11, further comprising means for refusing to configure the requested network slice indicated by the first information, if the identifying means determines that there is no path containing an IAB node to which the first IAB node can connect.

[0068] (Item 13) A communication device according to any one of items 3 to 12, characterized in that, based on receiving information from another IAB donor indicating the first IAB node, information indicating a network slice requested by the first IAB node, and information indicating an IAB node to which the first IAB node can connect, if the network slice requested by the first IAB node is not set in the second IAB node included in the communication path which includes an IAB node to which the first IAB node can connect, the transmitting means transmits a message to the second IAB node to cause it to set the requested network slice.

[0069] (Item 14) The communication device according to any one of items 3 to 13, characterized in that the transmission means does not transmit the message if the requested network slice is a predetermined network slice.

[0070] (Item 15) The communication device according to any one of items 3 to 13, characterized in that the transmission means does not transmit the message if the requested network slice is not a predetermined network slice.

[0071] (Item 16) The communication device according to any one of items 1 to 15, characterized in that the transmission means transmits the message including information indicating the expiration date of the network slice set by the message.

[0072] (Item 17) A control method performed by a communication device operating as an IAB donor or an IAB node connected to a communication path formed by an IAB donor in a relay transmission network compliant with the provisions of Integrated Access and Backhaul (IAB), A control method characterized by including sending a message to an IAB node connected to the communication path to configure a network slice.

[0073] (Item 18) A program to cause a computer to function as one of the means of a communication device described in any one of items 1 through 16.

[0074] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0075] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of symbols]

[0076] 102, 107: IAB donor, 103-106, 108-110: IAB node, 202: control unit, 203: memory unit, 308: network slice notification unit, 309: network slice collection unit, 310: network slice allocation unit

Claims

1. A communication device that operates as an IAB donor in a relay transmission network in accordance with the provisions of Integrated Access and Backhaul (IAB), The communication device has a transmission means that sends a message to an IAB node connected to the communication path formed by the communication device to set up a network slice. A communication device characterized in that, when a first IAB node is newly connected to the communication path, and a network slice requested via the first IAB node is not set up in the communication path, the transmitting means sends a message to the IAB node connected to the communication path to cause it to set up the requested network slice.

2. The communication device according to claim 1, wherein the transmitting means transmits a message to the second IAB node to set the requested network slice when the first IAB node is connected to the communication path and the requested network slice via the first IAB node is not set at the second IAB node included in the communication path.

3. Acquisition means for acquiring first information indicating the requested network slice from the first IAB node, A holding means for holding second information indicating the network slice configured by the second IAB node, A determination means for determining whether the requested network slice is configured at the second IAB node based on the first information and the second information, The communication device according to claim 2, further comprising the above.

4. The communication device according to claim 3, wherein the acquisition means further acquires the second information from the second IAB node.

5. The communication device according to claim 3, characterized in that the acquisition means acquires the first information from the connection request by the first IAB node.

6. The communication device according to claim 3, characterized in that the acquisition means acquires the first information when the first IAB node switches its connection destination from a third IAB node belonging to another communication path formed by the communication device to the second IAB node belonging to the communication path.

7. The communication device according to claim 3, wherein the acquisition means acquires the first information relating to a network slice when a terminal is connected to the first IAB node and the terminal requests communication for a network slice not configured in the first IAB node.

8. The communication device according to claim 3, further comprising a means for specifying a path that includes an IAB node to which the first IAB node can connect, which is capable of configuring the required network slice indicated by the first information, and which is capable of configuring the required network slice indicated by the first information, and which further specifies the communication path to which the first IAB node should connect.

9. The communication device according to claim 8, further comprising means for connecting the first IAB node to an IAB node that can be connected to the first IAB node, which is included in the communication path identified by the identifying means.

10. The communication device according to claim 8, further comprising notification means for notifying the other IAB donor of information indicating the first IAB node, information indicating the requested network slice indicated by the first information, and information indicating the IAB node to which the first IAB node can connect, when an IAB node to which the first IAB node can connect, which is included in the communication path identified by the identification means, belongs to another IAB donor different from the communication device, the other IAB donor.

11. The communication device according to claim 8, further comprising means for refusing to configure the network slice if the identifying means determines that there is no path containing an IAB node to which the first IAB node can connect.

12. The communication device according to claim 2, characterized in that, based on receiving information from another IAB donor indicating the first IAB node, information indicating a network slice requested by the first IAB node, and information indicating an IAB node to which the first IAB node can connect, if the network slice requested by the first IAB node is not set in the second IAB node included in the communication path which includes an IAB node to which the first IAB node can connect, the transmitting means transmits a message to the second IAB node to cause it to set the requested network slice.

13. The communication device according to claim 2, characterized in that the transmission means does not transmit the message if the requested network slice is a predetermined network slice.

14. The communication device according to claim 2, characterized in that the transmission means does not transmit the message if the requested network slice is not a predetermined network slice.

15. The communication device according to claim 1, characterized in that the transmission means transmits the message including information indicating the expiration date of the network slice set by the message.

16. A control method performed by a communication device operating as an IAB donor in a relay transmission network compliant with the provisions of Integrated Access and Backhaul (IAB), A control method characterized by including sending a message to an IAB node connected to the communication path to cause it to set up a requested network slice, when a first IAB node is newly connected to the communication path formed by the communication device, and a network slice requested via the first IAB node is not set up in the communication path.

17. A program for causing a computer to function as one of the means of a communication device according to any one of claims 1 to 15.

Images