Communication device, control method, and program

Abstract

A communication device operates as an integrated access and backhaul (IAB) node in a relay transport network conforming to an IAB specification, the IAB node being connected to one of an IAB donor and a communication path formed by the IAB donor, the communication device transmitting a message for causing the IAB node connected to the communication path to set a network slice.

Description

Technical Field

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

[0002] Third Generation Partnership Program Cellular communication standards are defined. In the cellular communication standards in 3GPP (hereinafter referred to as "3GPP standards"), integrated access and backhaul (IAB) that integrates access lines and backhaul lines is being standardized (see PTL 1). In IAB, radio resources used for access lines between base stations and user terminals (UEs) are also used for backhaul lines. For example, radio resources in millimeter wave bands such as 28-GHz bands can be used in IAB. By using IAB, a relay device (IAB node) can relay communication between a base station device (IAB donor) and a terminal device through a wireless line. Compared with the case of using a wired line such as an optical fiber, it is possible to expand regional coverage at a low cost.

[0003] In the 3GPP standard, network slicing technology is adopted to meet the required qualities such as bandwidth and latency applicable to various communication services by virtually dividing the network (see PTL 2 and PTL 3). In the 3GPP standard, eMBB, URLLC and MIoT are defined as slice / service types (SST). It should be noted that eMBB is an abbreviation for enhanced mobile broadband, and represents a service type for enhanced mobile broadband. URLLC is an abbreviation for high reliability and low latency communication, and represents a service type for high reliability and low latency. MIoT is an abbreviation for massive Internet of Things, and represents a service type for establishing multiple connections at the same time.

[0004] Reference List

[0005] Patent Literature

[0006] PTL 1 (Patent Document 1): Japanese Patent Laid-Open No. 2018-525874

[0007] PTL 2 (Patent Document 2): Japanese Patent Laid-Open No. 2020-511848

[0008] PTL 3 (Patent Document 3): Japanese Patent Laid-Open No. 2018-160772 Summary of the invention

[0009] Technical issues

[0010] In the case of applying network slicing to a network configuration using IAB, it is necessary to perform an operation for setting a slice corresponding to a service requested by the UE in each of one or more IAP nodes included in a communication path up to a user terminal (UE).

[0011] Solution to the problem

[0012] The present invention provides a method for effectively applying network slicing in a network configuration using IAB.

[0013] A communication device according to one aspect of the present invention is a communication device, which operates as an integrated access and backhaul (IAB) node in a relay transmission network that complies with the IAB regulations, and the IAB node is connected to an IAB donor and one of the communication paths formed by the IAB donor. The communication device includes: a sending device, which is used to send a message for the IAB node connected to the communication path to set a network slice.

[0014] Beneficial effects of the present invention

[0015] According to the present invention, network slicing can be effectively applied in a network configuration using IAB.

[0016] Other features and advantages of the present invention will become apparent from the following description in conjunction with the accompanying drawings.It should be noted that the same reference numerals in all drawings represent the same or similar components. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0018] Figure 1 is a diagram showing a configuration example of a wireless communication system;

[0019] Figure 2 is a block diagram showing an example of a hardware configuration of an IAB donor;

[0020] Figure 3 is a block diagram showing an example of a functional configuration of an IAB donor;

[0021] Figure 4 is a diagram showing an example of information for associating a communication path and a network slice;

[0022] Figure 5A is a view showing a structural example of information included in a message to be transmitted / received;

[0023] Figure 5B is a view showing a structural example of information included in a message to be transmitted / received;

[0024] Figure 6 is a flowchart showing an example of a process flow performed by an IAB donor;

[0025] Figure 7 is a sequence diagram showing an example of a communication process flow performed in a wireless communication system;

[0026] Figure 8 is a diagram showing a configuration example of a wireless communication system;

[0027] Fig. 9 is a diagram showing an example of information for associating a communication path and a network slice; and

[0028] Fig.10 is a flowchart showing an example of a process flow performed in a wireless communication system. DETAILED DESCRIPTION

[0029] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the scope of the claimed invention. A plurality of features are described in the embodiments, but the present invention is not intended to be limited to requiring all of these features, and a plurality of such features may be appropriately combined. In addition, in the accompanying drawings, the same reference numerals are assigned to the same or similar configurations, and their repeated descriptions are omitted.

[0030] (First embodiment)

[0031] Figure 1 A configuration example of a wireless communication system according to this embodiment is shown. Figure 1 The wireless communication system 100 shown is configured to include a relay transmission network that complies with the Integrated Access and Backhaul (IAB) specification in the 3rd Generation Partnership Project (3GPP). In the IAB relay transmission network, wireless communication in which access lines and backhaul lines are integrated is performed. The IAB relay transmission network will be referred to as the IAB network hereinafter. The IAB network is configured to include IAB donors (e.g., IAB donors 102 and IAB donors 107) and IAB nodes (e.g., IAB nodes 103 to 106 and IAB nodes 108 to 110). Communication services are provided to terminals (e.g., terminal 111) residing in an area (e.g., area 112) provided by any node (IAB donor or IAB node) via relay transmission of these IAB donors and IAB nodes. It should be noted that Figure 1 The configuration shown is merely an example, and there may of course be more IAB donors, more IAB nodes, and more terminal devices.

[0032] The IAB Donor treats the IAB Node as a terminal, establishes a connection, and then performs setup based on the Backhaul Adaptation Protocol (BAP). Once setup is completed, the IAB Node acts as a relay. Note that the IAB Donor can accommodate multiple IAB Nodes. Figure 1In the example of , IAB donor 102 accommodates IAB nodes 103 to 106 and IAB node 110, and IAB donor 107 accommodates IAB nodes 108 and 109. It should be noted that multiple IAB nodes can be connected in series so that, for example, IAB node 109 is connected on the downstream side of IAB node 108. Multiple IAB nodes can be connected in parallel with a common IAB donor (or IAB node) so that IAB node 102 and IAB node 104 are connected on the downstream side of IAB donor 102. The IAB donor is configured to be able to connect to the core network (CN 101) using, for example, a wired line. The IAB donor and the core network can be connected through, for example, an Internet Protocol (IP) network. It should be noted that communication from the IAB-based core network to each IAB node will sometimes be referred to as backhaul communication to distinguish it from communication via an access line between an IAB donor or IAB node and a terminal. Among the nodes (IAB donors or IAB nodes) directly connected in the communication path, the node connected to the side (upstream side) close to the core network when viewed from the designated IAB node will sometimes be referred to as the "parent node" of the IAB node hereinafter. In addition, among the IAB nodes directly connected in the communication path, the node connected to the side (downstream side) far from the core network when viewed from the designated IAB node will sometimes be referred to as the "child node" hereinafter.

[0033] Reference Figure 1 , IAB node 103 and IAB node 104 are connected to IAB donor 102 as child nodes. IAB node 105 is connected to IAB node 103 as a child node, and IAB node 110 is connected to IAB node 105 as a child node. In this way, IAB donor 102, IAB node 103, IAB node 105 and IAB node 110 are connected in sequence, thereby forming a communication path from IAB donor 102 to IAB node 110. In this example, the communication path is referred to as "path 1". IAB node 106 is connected to IAB node 104 as a child node. In this way, IAB donor 102, IAB node 104 and IAB node 106 are connected in sequence, thereby forming a communication path from IAB donor 102 to IAB node 106. In this example, the communication path is referred to as "path 2". In addition, IAB node 108 is connected to IAB donor 107, and IAB node 109 is connected to IAB node 108 as a child node. This sequentially connects the IAB donor 107 , the IAB node 108 , and the IAB node 109 , thereby forming a communication path from the IAB donor 107 to the IAB node 109 .

[0034] The terminal can connect to the core network via the IAB donor and the IAB node. Figure 1, terminal 111 is connected to cell 112 provided by IAB node 110 , and is connected to CN 101 via IAB node 110 , IAB node 105 , IAB node 103 , and IAB donor 102 .

[0035] It should be noted that the wireless communication system is configured to apply network slicing. In this case, according to the communication service to be used by the terminal device connected to the IAB node, it is necessary to set the corresponding network slice not only in the IAB node but also in the IAB node on the upstream side of the IAB node. For example, it is assumed that a communication service corresponding to ultra-reliable and low-latency communication (URLLC) is provided to the terminal 111 connected to the IAB node 110. In this case, it is necessary to set the URLLC network slice not only in the IAB node 110 but also in the IAB node 103 and the IAB node 105. For example, the same applies to the case where a communication service corresponding to enhanced mobile broadband (eMBB) is provided to the terminal 111 or another terminal. That is, the eMBB network slice should be set not only in the IAB node 110 but also in the IAB node 103 and the IAB node 105. As described above, a suitable communication environment can be provided for various services by setting network slices in all IAB nodes forming a communication path.

[0036] In IAB, for example, radio resources of a millimeter wave band such as a 28-GHz band can be used, but radio waves in the millimeter wave band may be strongly attenuated depending on weather conditions. In addition, when there are obstacles on the propagation path, due to the straightness of radio waves, radio waves in high frequency bands such as the millimeter wave band cannot propagate around obstacles, so communication may not be maintained. When the millimeter wave band is to be used in a radio link set between an IAB donor and an IAB node or between two IAB nodes, a radio link failure (RLF) may occur to temporarily hinder communication in the radio link. It should be noted that RLF can be referred to as BH RLF to clarify that RLF is an RLF in a backhaul (BH) line. When BH RLF occurs, the IAB node on the downstream side in the section where BH RLF occurs will look for another connectable IAB node to perform a connection, and establish a new route to the IAB donor, thereby enabling the backhaul communication to be restored. It can also be assumed that even in the case of an RLF different from BH RLF, when the communication quality with the parent node changes, the IAB node should change the established route. In addition, in the IAB framework, topological redundancy can be provided, and the IAB node can set up links for backhaul communication with multiple parent nodes. For example, the IAB node 110 can establish a connection with the IAB node 106 while establishing a connection with the IAB node 105. It should be noted that the IAB node 110 is connected to the path 1 but not to the path 2, unless otherwise specified.

[0037] It can be assumed that the network slice set before the connection destination of the IAB node whose connection destination is to be changed is changed is not set in the IAB node that is a connection destination candidate after the change. For example, it is assumed that the IAB node 110 that sets up URLLC and eMBB switches the connection destination from the IAB node 105 to another IAB node. It is also assumed that the IAB node 110 detects the IAB node 106 as a connection destination candidate that exists around after the change. In this case, since the setting of the URLLC network slice is not performed in the IAB node 106, the setting needs to be performed. It is also necessary to perform the setting of the URLLC network slice in the IAB node 104 connected to the IAB node 106. On the contrary, by predicting that the IAB node 110 will be connected, the setting of the URLLC network slice can be performed in advance in the IAB node 106 and the IAB node 104, for example manually and separately. However, when performing such a setting, it is necessary to perform the setting separately for a large number of IAB nodes, which is cumbersome. In addition, for example, when the IAB node 110 is connected to the IAB node 106, the setting of the URLLC network slice may be performed in the IAB node 106 by issuing a predetermined request to the IAB node 106. However, since the setting of the URLLC network slice is not performed in the IAB node 104, the IAB node 106 is to send a network slice setting request to the IAB node 104. As described above, it is assumed that when the setting is sequentially performed in the corresponding IAB nodes forming the path by tracing back the path, a lot of time is required to complete the setting, and the efficiency is not high.

[0038] In this embodiment, in consideration of the above-mentioned problems, the IAB donor manages the network slices that are set in each path, and according to the change of the connection destination, the setting of the network slices in the path is uniformly performed after the connection destination of the IAB node subordinate to the IAB donor is changed. It should be noted that "IAB donor subordinate" means the communication path managed by the IAB donor and the IAB node that forms the communication path. Figure 1 In the example shown, the IAB nodes under the IAB donor 102 are the IAB nodes 103 to 106 and the IAB node 110, and the IAB nodes under the IAB donor 107 are the IAB nodes 107 to 109. The IAB donor 102 retains information on the network slices set in each of the paths 1 and 2, for example. Then, when the IAB node 110 changes the connection destination to the IAB node 106, the IAB donor 102 sets the network slice set in the IAB node 110 in the path from the IAB node 106 to the IAB donor 102. Figure 1In the example shown, the IAB donor 102 instructs to set the URLLC network slice not only in the IAB node 106 but also in the IAB node 104. In this way, the network slices can be uniformly set for the corresponding IAB nodes on the path, and communication can be quickly performed through the appropriate network slice after the IAB node 110 switches the communication path.

[0039] An example of a configuration of an IAB donor that performs control processing and an example of a processing flow will be described below. It should be noted that the functions of the IAB donor to be described below may be reserved by some IAB nodes. For example, when multiple paths are formed via multiple sub-nodes connected in parallel via an IAB node, the IAB node may manage information about the multiple paths and set network slices.

[0040] (Device Configuration)

[0041] Figure 2 An example of the hardware configuration of the communication device 201 used as the IAB donor according to this embodiment is shown. It should be noted that the case where the communication device 201 has the function of the IAB donor will be described, but the communication device used as the IAB node can have the same configuration. It should be noted that some of the IAB nodes can have the configuration described below. That is, the remaining IAB nodes can have different configurations. Figure 2 The configuration shown is only an example, and the communication device 201 can be Figure 2 For example, the communication device 201 need not include Figure 2 Some hardware components are shown, and additional components may be included.

[0042] For example, as a hardware configuration, the communication device 201 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 and an MPU, and controls the entire device by executing a control program stored in the storage unit 203. It should be noted that CPU is an abbreviation for a central processing unit, and MPU is an abbreviation for a microprocessing unit. The control unit 202 can be configured to include, for example, one or more of a field programmable gate array (FPGA), a digital signal processor (DSP), and an application-specific integrated circuit (ASIC), each of which is configured to perform a predetermined process. The storage unit 203 is configured to include one or more memories such as a read-only memory (ROM) and a random access memory (RAM), and one or more storage devices such as a hard disk drive (HDD) and a solid-state drive (SSD). The storage unit 203 stores, for example, a control program to be executed by the control unit 202 and various information (for example, communication-related information including cell information, connection terminal information, and IAB routing information). For example, when the control unit 202 executes the control program stored in the storage unit 203, various operations described below are implemented. The wireless communication unit 204 is configured to include a A radio frequency (RF) chip or a baseband (BB) chip for wireless communication of the long term evolution (LTE) standard or 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. It is to be noted that, for example, hardware for performing only antenna control may be prepared separately as the antenna control unit 205, or the antenna control unit 205 may be formed as part of the BB chip or the RF chip.

[0043] Figure 3 An example of a functional configuration 301 of the communication device 201 is shown. It is to be noted that a case where the communication device 201 has the function of an IAB donor will be described, but a communication device used as an IAB node may have the same configuration. It is to be noted that some of the IAB nodes may have the configuration described below. That is, the remaining IAB nodes may have different configurations. Figure 3 The configuration shown is only an example, and the communication device 201 can be Figure 3 The functional configuration 301 shown in FIG. 3 is implemented by different functional configurations. For example, the communication device 201 does not need to have Figure 3 Some of the functionality is shown, and additional components may be included.

[0044] As a functional configuration 301, the communication device 201 includes, for example, the functions of a general base station device in a cellular communication system. As the functions of a general base station device, the functional configuration 301 includes, 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 notification signal generation unit 307. In addition, the functional configuration 301 of the communication device 201 includes functions associated with network slicing. The functions associated with network slicing include, for example, a network slice notification unit 308, a network slice collection unit 309, and a network slice allocation unit 310.

[0045] The signal receiving unit 302 and the signal sending unit 303 perform wireless communication in accordance with the LTE or 5G cellular communication standard with the terminal device. The data storage unit 304 stores the software itself, IAB routing information, information about the connected terminal, etc. The data storage unit 304 can store, for example, a public land mobile network identification (PLMN ID). The PLMN ID is an ID for identifying a communication operator, and is set by the communication operator in the communication device 201 and stored in the data storage unit 304.

[0046] The connection control unit 305 performs connection control with the terminal or core network function. For example, the connection control unit 305 performs processing associated with the connection or disconnection of the terminal with the cellular network. As an example, the connection control unit 305 performs processing such as synchronization establishment processing with each terminal device. The RRC control unit 306 performs connection control in the RRC layer, including sending / receiving radio resource control (RRC) messages with the terminal or core network function. For example, for a newly connected IAB node or such an IAB node whose connection has been switched from an IAB node under another IAB donor to an IAB node under its own device, the RRC control unit 306 establishes an RRC connection by treating the IAB node as a terminal. In addition, when the IAB node changes the IAB donor as a relay source for backhaul communication or changes the connection destination IAB node, the RRC control unit 306 can send a message for requesting the terminal currently connected to the IAB node to release the RRC connection. For each cell provided by the communication device 201, the notification information generation unit 307 periodically sends notification information including system information and information for decoding the system information to the surrounding. By receiving the notification information, another base station device or terminal can recognize the presence of a base station device located near its own device and perform connection processing with the base station device.

[0047] The network slice notification unit 308 and the network slice collection unit 309 perform processing to enable the IAB donor to share network slice information with the connection source under the IAB donor. For example, the network slice notification unit 308 notifies another IAB node or terminal directly connected or connected to the IAB node under the IAB donor of the network slice information supported by the IAB donor. The network slice collection unit 309 collects network slice information supported or requested by another IAB node or terminal from another IAB node or terminal directly connected or connected to the IAB node under the IAB donor. The network slice allocation unit 310 enables the IAB donor to allocate network slices to another IAB node. It should be noted that the IAB node can notify another IAB node or a terminal under the IAB node of the network slice information supported by its own device, and collect network slice information requested by another IAB node or terminal.

[0048] The IAB donor (in some cases, the IAB node) stores the communication path managed by its own device and the network slice set in the communication path in association with each other. For example, the IAB donor 102 can retain information indicating that the eMBB and URLLC network slices are set as information about path 1. Figure 4 An example of information of network slices set for each path based on a request from an IAB node subordinate to and managed by an IAB donor (in some cases, an IAB node) is shown. The IAB donor 102, for example, stores information indicating eMBB and URLLC network slices set in the IAB nodes 103, 105, and 110 included in path 1 as shown in information 401. In addition, the IAB donor 102 stores information indicating eMBB network slices set in the IAB nodes 104 and 106 included in path 2.

[0049] It is assumed here that the IAB node 110, which has set the eMBB and URLLC network slices, requests the IAB node 106 to perform a new connection. In this case, the IAB donor 102 recognizes that the eMBB network slice has been set in the IAB node 104 and the IAB node 106 of path 2 based on information 401, and the URLLC network slice has not been set. The IAB donor 102 allocates the URLLC network slice to the IAB node 104 and the IAB node 106, so that the IAB node 110 can continue to communicate based on the eMBB and URLLC network slices. Then, after allocating the URLLC network slice to the IAB node 104 and the IAB node 106, the IAB node 110 establishes a connection with the IAB node 106. After performing this process, the IAB donor 102 stores information indicating that the setting of the eMBB and URLLC network slices is performed in the path 2 to which the new IAB node 110 is connected as shown in information 402. It should be noted that the IAB donor 102 can, for example, disconnect the IAB node 110 from the path 1. In this case, the allocation of network slices of the IAB node 103 and the IAB node 105 remaining in the path 1 may be updated. For example, if only eMBB is requested in the IAB node 103 and the IAB node 105, and URLLC is unnecessary, the IAB donor 102 may cancel the allocation of the URLLC network slice.

[0050] Figure 5A The format of the single network slice selection assistance information (S-NSSAI) to be used to notify network slice information is shown. When, for example, an IAB donor or an IAB node notifies the network slice information supported by itself or notifies the network slice information requested by the IAB node or a terminal connected to the IAB node, the S-NSSAI is used Figure 5A The format shown. Figure 5AThe format shown includes a slice service type (SST) field and a slice distinguisher (SD) field. Information of eMBB, URLLC, or mMTC is set as the classification of the network slice in the SST field, and optional information for further subdividing the network slice represented by the SST field is set in the SD field. It should be noted that if further classification of network slices is defined in addition to eMBB, URLLC, and mMTC, information representing the further classification can be set in the SST field. For example, the IAB node sends a message to the IAB donor obtained by setting a value in the SSD and SD fields indicating the network slice requested to be used by the IAB node or the network slice supported by the IAB node. For example, the IAB donor sends a message to the IAB donor under the IAB donor by setting a value in the SSD and SD fields indicating the network slice supported by its own device. It should be noted that NSSAI including multiple S-NSSAIs can be sent / received between the IAB donor and the IAB node.

[0051] Figure 5B The format of the S-NSSAI to be used by the IAB donor (or IAB node) to allocate or cancel network slices to the IAB nodes under the IAB donor is shown. In addition to the SST and SD fields, Figure 5B The format shown also includes a Slice Allocate field, which indicates that the setting value when allocating a network slice is "ON" and the setting value when canceling the allocation of the network slice is "OFF". It should be noted that in the example, when the value of the Slice Allocate field is 1, it can represent "ON"; and when the value of the Slice Allocate field is 0, it can represent "OFF". The IAB donor (or IAB node) sends a message obtained by setting the value representing the network slice requested by the IAB node or the currently connected terminal in the SST and SD fields and setting the Slice Allocate field to "1" to the IAB node under the IAB donor. In addition, the IAB donor (or IAB node) can send a message obtained by setting the Slice Allocate field to "0" based on the fact that the currently connected terminal is disconnected, the fact that the IAB node under the IAB donor moves to become another IAB donor subordinate, etc. It should be noted that in this case, the value representing the network slice set in response to a request from the IAB node or terminal can be set in the SST and SD fields. The message may be sent to each IAB node forming a path including an IAB node to which the disconnected terminal was originally connected or an IAB node that moves to become subordinate to another IAB donor.

[0052] (Processing flow)

[0053] Next, we will refer to Figure 6An example of a process flow performed by an IAB donor (or IAB node) is described. This process is performed when another IAB node is connected to any IAB node constituting a communication path subordinate to the IAB donor (or IAB node). It is to be noted that this process can be implemented, for example, when the control unit 202 executes a program stored in the storage unit 203. The following description focuses on the IAB donor 102.

[0054] First, the IAB donor 102 detects a connection request to another IAB node 106 that can be connected by the IAB node 110 (step S601). For example, when the IAB node 110 measures the surrounding wireless environment and identifies a connectable IAB node 106, it sends a connection request to the IAB node 106. At this time, the connection request includes Figure 5A The S-NSSAI shown. It is to be noted that the connection request includes an S-NSSAI including an SST field set with URLLC and an S-NSSAI including an SST field set with eMMB. This allows the IAB donor 102 to identify the network slice requested by the IAB node 110. The IAB donor 102 determines, based on the information 401, whether all network slices requested by the IAB node 110 identified in step S601 have been set in path 2 including the IAB node 106 which is the connection request destination of the IAB node 110 (step S602). For example, referring to the information 401, the IAB donor 102 identifies that an eMMB network slice has been set in path 2 including the IAB node 106. Then, the IAB donor 102 can identify that the URLLC network slice requested by the IAB node 110 has not yet been set ("Yes" in step S602). In this case, the IAB donor 102 notifies the IAB node 104 and the IAB node 106 included in the path 2 of the allocation of the URLLC network slice (step S603). For example, the IAB donor 102 sends a message to the IAB node 104 and the IAB node 106, the message having Figure 5BThe format shown is obtained by setting URLLC in the SST field and setting ON in the slice allocation field at the same time. The IAB node 104 and the IAB node 106 set the URLLC network slice by receiving the message. Then, after completing the setting of the network slices in the IAB node 104 and the IAB node 106, the IAB donor 102 completes the connection between the IAB node 110 and the IAB node 106 (step S604). It should be noted that this is just an example, and the IAB donor 102 can set the network slice while establishing the connection with the IAB node 110, or can set the network slice after establishing the connection with the IAB node 110. It should be noted that if the IAB donor 102 recognizes that all network slices requested by the IAB node 110 have been set ("No" in step S602), the IAB donor 102 can establish a connection with the IAB node 110 without setting any new network slices (step S604).

[0055] As described above, based on the network slice requested by the IAB node connected by the IAB donor 102, the IAB donor 102 can effectively set the network slice in another IAB node on the communication path to which the IAB node is connected. For example, if there is only another IAB node around the connection target IAB node that has not yet set the network slice requested by the IAB node, then the network slice is set in the communication path including the other IAB nodes. In particular, for each IAB node included in the communication path, the network slice can be uniformly set under the control of the IAB donor. Therefore, after the connection is established in the IAB node, the communication applicable to the network slice requested by the connection target IAB node can be quickly performed.

[0056] Figure 7 An example of a processing flow performed in a wireless communication system is shown. It should be noted that the following description focuses on the IAB donor 102 and the IAB nodes 103 to 106 and the IAB node 110 under the IAB donor 102, and the IAB donor 107 and the IAB nodes under the IAB donor 107 will not be described. When the IAB node 110 connected to the IAB node 105 switches the connection destination to the IAB 106, the operation of the IAB donor 102 allocating network slices to the IAB nodes 104 and the IAB 106 will now be described.

[0057] First, the setting of each path in the path 1 including the IAB node 103, the IAB node 105 and the IAB node 110 and the path 2 including the IAB node 104 and the IAB node 106 is performed under the control of the IAB donor 102 (S701). For example, the IAB donor 102 receives the NSSAI including the S-NSSAI representing the eMBB and the S-NSSAI representing the URLLC, and sets the eMBB and URLLC network slices in the IAB node 103. Similarly, the IAB donor 102 sets the eMBB and URLLC network slices in the IAB node 105 connected to the IAB node 103 and the IAB node 110 connected to the IAB node 105. It should be noted that, Figure 7 An example of a case where eMBB and URLLC network slices are set in each of the IAB node 103 and the IAB node 105 at the time of connection is shown, but the present invention is not limited thereto. For example, based on a service requested by a terminal connected to its own device, only one of the eMBB and URLLC network slices may be set in the IAB node 103 and the IAB node 105. Thereafter, in response to a request by the IAB node 110 to perform a connection on the IAB node 105, an unset network slice in the eMBB and URLLC network slices may be set in the IAB node 103 and the IAB node 105. Through the above operation, eMBB and URLLC network slices are set in each IAB node of path 1. On the other hand, similar to the above process, only eMBB network slices may be set in the IAB node 104 and the IAB node 106 forming path 2.

[0058] Thereafter, it is assumed that the IAB node 110 changes the connection destination to the IAB node 106 as the wireless environment changes or the device moves. At this time, the IAB node 110 sends an NSSAI including an S-NSSAI corresponding to eMBB and an S-NSSAI corresponding to URLLC to the IAB node 106 (S702). The IAB node 106 forwards the NSSAI to the IAB donor 102 via the IAB node 104. It should be noted that this is merely an example, and the IAB node 110 may, for example, include the NSSAI in the information indicating that the IAB node 106 is set as the connection switching destination, and send a message via the path 1 where the connection is established at this time. In addition, the IAB donor 102 already knows the network slice requested by the IAB node 110 in S701. Therefore, the IAB node 110 may only notify the IAB donor 102 of the connection request to set the IAB node 106 as the connection switching destination.

[0059] Based on the connection request, IAB donor 102 detects that URLLC network slices have not been set in IAB node 104 and IAB node 106. Then, IAB donor 102 sends a URLLC network slice to each of IAB node 104 and IAB node 106. Figure 5B The message shown, wherein ON is set in the slice allocation field and URLLC is set in the SST field (S703 and S704). In this way, the URLLC network slices are uniformly allocated to the IAB node 104 and the IAB node 106. Thereafter, the IAB node 110 establishes synchronization of the downlink based on the synchronization signal from the IAB node 106, and establishes synchronization of the uplink through the random access channel (RACH) process (S705). Then, the IAB node 110 establishes an RRC connection with the IAB node 106 (via the IAB node 106 to the IAB donor 102) (S706). Thereafter, the IAB donor 102 updates the connection information (including the routing information of the IAB node connected to the subordinate of the IAB donor 102), and establishes a route between the IAB donor 102 and the IAB node 110. In this way, a communication environment suitable for the service can be provided to the terminal set up using the required network slice immediately after the IAB node 110 is connected in the path from the IAB donor 102 to the IAB node 110.

[0060] (Second embodiment)

[0061] Figure 8 800 according to this embodiment. In the wireless communication system 800, a path 1 including an IAB node 803 and an IAB node 805 and a path 2 including an IAB node 804, an IAB node 806, and an IAB node 810 are formed under the IAB donor 802. In the paths 1 and 2, eMBB network slices are set. In this case, for the paths 1 and 2, the IAB donor 802 retains information indicating the IAB nodes included in each path, and information indicating the (corresponding) network slices set in each path, such as Fig. 9 As shown in the information 901 shown. In addition, a path including the IAB node 808 and the IAB node 809 under the IAB donor 807 is formed, and the eMBB network slice is set. It should be noted that the IAB donor 807 also retains the same information as the information 901 (not shown).

[0062] In this state, it is assumed that a terminal 811 located in a cell 812 provided by an IAB node 810 and currently connected to the IAB node 810 requests the IAB node 810 to perform URLLC communication. For example, the terminal 811 in an unconnected state sends a connection request for URLLC communication to the IAB node 810. The terminal 811 currently connected to the IAB node 810 may send a message for requesting URLLC communication to the IAB node 810 in response to the launch of a new application, etc. At this time, the IAB node 810 requests the IAB donor 802 to set a URLLC network slice. The IAB donor 802 determines whether a URLLC network slice can be set in a communication path under the IAB donor 802. If the URLLC network slice can be set, the network slice is set as in the first embodiment.

[0063] On the other hand, if it is determined that the URLLC network slice cannot be set in any communication path under the IAB donor 802, the IAB donor 802 determines whether the connection can be performed via another IAB donor having a subordinate IAB node that can be connected to the IAB node 810. For example, the IAB donor 802 obtains the measurement result of the notification signal or reference signal from another surrounding IAB node in the IAB node 810, and identifies another IAB node other than its own device under the IAB donor as an IAB node of the connection switching destination candidate. Then, the IAB donor 802 determines whether the IAB node of the connection switching destination candidate can set the URLLC network slice. For example, the IAB node 810 can refer to the notification signal from another surrounding IAB node, etc. to identify the network slice that another IAB node can support, and notify the IAB donor 802 of the identification result. In the example, the IAB donor 802 can extract an IAB node that can support the URLLC network slice, and identify the IAB node as a connection switching destination candidate for the IAB node 810. In addition, the IAB node 810 may send a report on the measurement results of another IAB node that can support the network slice requested by its own device, etc., only to the IAB donor 802. In addition, when obtaining information about the IAB node of the connection switching destination candidate from the IAB node 810, the IAB donor 802 may ask the IAB donor having the subordinate IAB node whether the URLLC network slice can be supported.

[0064] It is assumed here that the IAB donor 807 can support URLLC network slicing, and the IAB node 808 is identified as a connection switching destination candidate of the IAB node 810. In this case, the IAB donor 802 decides to switch (transfer) the connection destination of the IAB node 810 from the IAB node 806 to the IAB node 808. At this time, the IAB donor 802 notifies the IAB donor 807 of the information of the IAB node 810, the fact of requesting the URLLC network slicing, the information of the IAB node 808 indicating the connection switching destination candidate, and the like. Based on the notification, the IAB donor 807 notifies the IAB node 808 of the allocation of the URLLC network slice. In this way, the URLLC network slice is set in the communication path from the IAB donor 807 to the IAB node 808. Thereafter, the IAB node 110 establishes a connection with the IAB node 808.

[0065] After the connection switching process, for example, the IAB donor 802 retains the information acquired by excluding the IAB node 810 from the path 2, as shown in FIG. Fig. 9 As shown in the information fragments of paths 1 and 2 of information 902 shown. At this time, the URLLC network slice is not set in paths 1 and 2, so the corresponding network slice information remains unchanged. On the other hand, the IAB donor 807 newly retains the information of the path obtained when the IAB node 810 is connected to the IAB node 808, as shown in the information of path 3 of information 902. It should be noted that the URLLC network slice is set in path 3, so the URLLC network slice is included as the corresponding network slice. It should be noted that for Fig. 9 As shown in the information 902, each of the IAB donor 802 and the IAB donor 807 can retain part of the information about the communication path of the IAB donor subordinates, as described above. In the example, each of the IAB donor 802 and the IAB donor 807 can retain all of the information 902. That is, the IAB donor 802 can retain not only the information about the communication path managed by its own device, but also the information about the communication path managed by another IAB donor in the surrounding.

[0066] Next, we will refer to Fig.10 An example of a process flow performed in a wireless communication system is described. Note that the IAB node 810 is connected to the IAB node 806 under the IAB node 802, and the URLLC network slice cannot be set in this state, as described above. When the control unit 202 of the IAB donor or IAB node, which is the operating subject of each process, executes the program stored in the storage unit 203, the following process is implemented.

[0067] In this process, first, the IAB node 810 requests the currently connected IAB donor 802 to set the URLLC network slice (step S1001). For example, the IAB node 810 may send a message including S-NSSAI to the IAB donor 802 via the currently connected IAB node 806, in which the URLLC is set in the SST field of the format shown in FIG. 5A. The setting request for the URLLC network slice may be sent by, for example, forwarding a message for requesting the URLLC network slice sent from the terminal 812 to the IAB node 810 to the IAB donor 802. That is, the IAB donor 802 may be notified that the URLLC network slice should be set in the IAB node 810, and there is no need to perform specific determination processing in the IAB node 810, etc. It should be noted that when the IAB node 810 requests an initial connection with the IAB donor 802, the URLLC network slice may be requested. In this case, the IAB node 810 may send a connection request including a request for the URLLC network slice to the IAB node 805 or the IAB node 806 present in the surroundings. In this case, upon receiving the connection request, the IAB node 805 or the IAB node 806 forwards the connection request to the IAB donor 802 .

[0068] The IAB donor 802 determines whether the network slice requested from the IAB node 810 has been set in the communication path including the IAB node as the connection destination of the IAB node 810 (step S1002). If the network slice has been set ("Yes" in step S1002) and if the connection between the IAB node 806 and the IAB node 810 has not been established, the IAB donor 802 establishes the connection (step S1005). The IAB donor 802 sets the network slice relative to the IAB node 810, thereby completing the processing. On the other hand, if the network slice has not been set ("No" in step S1002), the IAB donor 802 determines whether the requested network slice can be set in the communication path under its own device (step S1003). That is, if, for example, a request is received from the IAB node 810 connected to the IAB node 806, the IAB donor 802 determines whether the URLLC network slice can be allocated in the path 2 including the IAB node 806. In addition, if the IAB donor 802 determines that the URLLC network slice cannot be allocated in path 2, it can determine whether the network slice can be allocated in another path under its own device that can connect to the IAB node 810. If it is determined that the requested network slice can be allocated in the path under its own device that can connect to the IAB node 810 ("Yes" in step S1003), the IAB donor 802 performs the allocation of the network slice (step S1004). Then, the IAB node 810 is connected to the IAB node on the path to which the network slice has been allocated (step S1005). It should be noted that if the network slice can be set without changing the connection destination of the IAB node 810, the processing of step S1005 can be omitted.

[0069] If it is determined that the requested network slice cannot be allocated in the path that is subordinate to the own device and can connect to the IAB node 810 ("No" in step S1003), the IAB donor 802 advances the processing to step S1006. In step S1006, the IAB donor 802 obtains information about the IAB node subordinate to another IAB donor (for example, the IAB donor 807) that can connect to the IAB node 810. It should be noted that the IAB node that can connect to the IAB node 810 is, for example, an IAB node that sends a notification signal at a power level such that the IAB node 810 can receive the signal. For example, the IAB donor 802 can obtain the information from the IAB node 810 through the measurement result of the notification signal notified by the IAB node 810, etc. It should be noted that the IAB donor 802 can retain in advance the information of the node that provides the adjacent cell from another IAB donor (the other IAB donor has a subordinate IAB node that forms a cell adjacent to the cell provided by the IAB node subordinate to the own device). Then, the IAB donor 802 may specify an IAB node under another IAB donor as a cell to be measured to the IAB node 810. In this case, for at least some of the specified IAB nodes, the IAB node 810 may notify the IAB donor 802 of the identification information of each IAB node and the measurement results of the radio quality in association with each other. For example, the IAB donor 802 may obtain in advance the information of the IAB node under another IAB donor to which the URLLC network slice can be allocated. This allows the IAB donor 802 to identify whether there are IAB nodes that can support URLLC network slicing around the IAB node 810. It is assumed here that the IAB donor 802 identifies that the IAB node 808 under the IAB donor 807 is an IAB node that can support URLLC network slicing and can be connected to the IAB node 810.

[0070] The IAB donor 802 sends the information of the IAB node 810, the network slice information requested by the IAB node 810, and the information of the IAB node 808 to the IAB donor 807 that manages the IAB node 808 (step S1007). That is, the IAB donor notifies another IAB donor that manages another IAB node as a connection destination of information for identifying the IAB node under its own device, information of another IAB node that should be the connection destination of the IAB node, and the requested network slice information. Then, the IAB donor 807 notifies the IAB node 808 that is the connection destination of the IAB node 810 of the allocation of the requested network slice (step S1008), and sets the network slice in the IAB node 808. The IAB node 810 is connected to the IAB node on the path to which the network slice is allocated (step S1005).

[0071] It should be noted that in this embodiment, the network slice information requested by the IAB node 810 may be information indicating URLLC and eMMB, but may also be information indicating only URLLC. That is, in the example, while maintaining the path 2 supporting eMMB with the IAB node 810, the IAB donor 802 may connect the IAB node 810 to the IAB node 808 to allocate the URLLC network slice. In addition, URLLC and eMMB are represented as the network slice information requested by the IAB node 810, and the IAB donor 807 may set both URLLC and eMMB network slices in the path up to the IAB node 808.

[0072] It should be noted that in the above examples, the case where the IAB donor 802 can uniformly set network slices in the IAB nodes under its own device or cannot uniformly set network slices in the IAB nodes under its own device has been described, but the present invention is not limited to this. Figure 8 In the example, URLLC cannot be set in path 2 currently connected to the IAB node 810, but URLLC can be set in path 1. In this case, the IAB donor 802 can connect the IAB node 810 to path 1 under its own device. That is, the IAB donor 802 does not need to switch the connection destination on the IAB donor. The IAB donor 802 can decide to connect the IAB node 810 to an IAB node (or path) that can connect the IAB node 810 and for which the requested network slice can be set. Then, if the IAB node (or path) as the connection destination is not under its own device, the information for setting the network slice can be notified to the IAB donor who manages the IAB node as the connection destination as described above. If the IAB donor 802 recognizes that there is no IAB node (or path) that can connect the IAB node 810 and for which the requested network slice can be set, the IAB donor 802 can reject the request for setting the network slice by the IAB node 810.

[0073] It should be noted that in each of the above-mentioned embodiments, an example is described in which the IAB node establishes a connection after setting the network slice. However, when the network slice is not set after the connection is established, the setting can be performed as described above. At this time, if the network slice cannot be set in the communication path of the current connection, the process of changing the connection destination can be performed similarly to the second embodiment. In addition, when the IAB node requests a new connection, the network slice required by the IAB node can be set in advance. That is, the network slice to be set for the terminal can be identified in advance, and at the time of the initial connection of the IAB node that does not belong to any IAB donor, the network slice to be requested by the IAB node can be identified. At this time, for example, separate random access process resources corresponding to each network slice can be prepared, and the IAB donor can identify the network slice requested by the IAB node based on the resources to be used.

[0074] The above-mentioned embodiments have described an example in which an IAB donor allocates a network slice to an IAB node under the IAB donor, but the present invention is not limited thereto. For example, a newly connected or changed IAB node (IAB node 110 or IAB node 810) can use a Figure 5B In this case, once the IAB node as the connection destination receives the message in the format shown in FIG. Figure 5B The message with the format shown set to ON in the slice allocation field sets the network slice, and further forwards the message to the parent node. Similarly, the parent node also sets the network slice. By repeating this process, the network slice can be set in the path to the IAB donor. That is, the newly connected or changed IAB node (IAB node 110 or IAB node 810) of the connection destination can set the network slice for the IAB node on the path to the IAB donor by sending a message. When the newly connected or changed IAB node (IAB node 110 or IAB node 810) of the connection destination sends NSSAI to the IAB donor, the IAB node on the relay path to the IAB donor can obtain the NSSAI. Then, if the requested network slice is not set, the IAB node on the relay path to the IAB donor can autonomously set the network slice without waiting for instructions from the IAB donor.

[0075] It should be noted that the network slice setting according to the above-mentioned various embodiments can be performed only on a predetermined network slice. That is, if the IAB node requests to set a predetermined network slice when a new connection or a change of connection destination is made or based on a request of a terminal, the IAB node on the path connected to the IAB node can be made to set the network slice. On the other hand, if the IAB node requests to set a network slice other than a predetermined network slice, the IAB node on the path connected to the IAB node can be prevented from setting the network slice. In this case, if there is no path for which a network slice is set, the setting of the network slice requested by the IAB node can be rejected. On the contrary, if the IAB node requests to set a predetermined network slice, the IAB node on the path connected to the IAB node can be prevented from setting the network slice. In this case, if the IAB node requests to set a network slice other than a predetermined network slice, the IAB node on the path connected to the IAB node can be made to set the network slice. In this example, the predetermined network slice is, for example, eMMB, URLLC, MIoT, or C-V2X for which the value of the SST field is currently defined. C-V2X stands for Cellular Vehicle to Everything. It should be noted that these are just examples, and some preset network slices can be processed as predetermined network slices. According to this example, for example, it can be configured to automatically set a high priority network slice and request the communication operator to set the remaining network slices.

[0076] For each network slice set as described above, a predetermined validity period may be set. In this case, for example, Figure 5B The information shown stores the predetermined validity period in the message to be sent, and the predetermined validity period can be subsequently notified to each IAB node. This prevents unnecessary reservation of the set network slices and ensures radio resources and computing resources for the newly set network slices.

[0077] As described above, in this embodiment, the IAB donor or IAB node identifies whether the requested network slice is not set in the communication path between the IAB donor and the IAB node that newly establishes the connection or changes the connection destination. If there is an unset network slice, another IAB node on the path is caused to set the network slice. That is, the communication device operating as an IAB donor or IAB node according to this embodiment recognizes the lack of setting of the network slice requested by the IAB node newly connected to the communication path, and causes another IAB node on the path to automatically set the network slice. Therefore, in the IAB relay transmission system, the requested network slice can be automatically and appropriately set while flexibly setting / changing the communication path. Therefore, network slicing can be effectively applied in the network configuration using IAB.

[0078] The present invention can be implemented by the following process: providing a program for implementing one or more functions of the above-mentioned embodiments to a system or device via a network or storage medium, and causing one or more processors in a computer of the system or device to read and execute the program. The present invention can also be implemented by a circuit (e.g., ASIC) for implementing one or more functions.

[0079] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made within the spirit and scope of the present invention. Therefore, the following claims are made in order to inform the public of the scope of the present invention.

[0080] This application claims the benefit of Japanese Patent Application No. 2022-092393, filed on June 7, 2022, which is hereby incorporated by reference into this application.

Claims

1. A communication device, the communication device operating as an IAB node in a relay transmission network compliant with an integrated access and backhaul (IAB) regulation, the IAB node being connected to an IAB donor and one of a communication path formed by the IAB donor, the communication device comprising: A sending device, wherein the sending device is used to send a message for causing the IAB node connected to the communication path to set a network slice. 2 . The communication device according to claim 1 , wherein the communication device is the IAB donor that forms the communication path.

3. The communication device according to claim 1, wherein when a first IAB node is connected to the communication path and a network slice requested by the first IAB node is not set in a second IAB node included in the communication path, the sending device sends a message for causing the second IAB node to set the requested network slice.

4. The communication device according to claim 3, further comprising: An acquiring device, the acquiring device being configured to acquire, from the first IAB node, first information representing the requested network slice; A holding device, the holding device being used to hold second information representing the network slice set by the second IAB node; as well as A determination device, wherein the determination device is used to determine whether the requested network slice has been set in the second IAB node based on the first information and the second information. 5 . The communication device according to claim 4 , wherein the acquiring means further acquires the second information from the second IAB node. 6 . The communication device according to claim 4 , wherein the acquiring means acquires the first information from a connection request of the first IAB node.

7. The communication device according to any one of claims 4 to 6, wherein the acquisition means acquires the first information when the first IAB node switches a 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.

8. A communication device according to any one of claims 4 to 7, wherein when a terminal is connected to the first IAB node and the terminal requests communication of a network slice that is not set in the first IAB node, the acquisition device acquires the first information about the network slice.

9. The communication device according to any one of claims 4 to 8, further comprising a designation device, wherein the designation device is used to designate a path including an IAB node in which the requested network slice represented by the first information can be set and which can be connected to the first IAB node as a communication path to be connected to the first IAB node.

10. The communication device according to claim 9, further comprising means for connecting the first IAB node to an IAB node which is included in the communication path specified by the specifying means and which can be connected to the first IAB node.

11. The communication device according to claim 9 or 10 further includes a notification device, wherein the notification device is used to notify another IAB donor of information representing the first IAB node, information representing the requested network slice indicated by the first information, and information representing the IAB node that can be connected to the first IAB node, in a case where the IAB node included in the communication path specified by the specifying device and that can be connected to the first IAB node belongs to another IAB donor different from the IAB donor.

12. The communication device according to any one of claims 9 to 11 further includes a device for refusing to set the network slice when the designating device specifies that there is no path including an IAB node in which the requested network slice represented by the first information can be set and which can be connected to the first IAB node.

13. A communication device according to any one of claims 3 to 12, wherein based on the fact that information representing the first IAB node, information representing the network slice requested by the first IAB node, and information representing an IAB node capable of connecting to the first IAB node are received from another IAB donor, when the network slice requested by the first IAB node is not set in the second IAB node included in the communication path including the IAB node capable of connecting to the first IAB node, the sending device sends a message for causing the second IAB node to set the requested network slice.

14. A communication device according to any one of claims 3 to 13, wherein the sending device does not send a message when the requested network slice is a predetermined network slice.

15. A communication device according to any one of claims 3 to 13, wherein the sending device does not send a message if the requested network slice is not a predetermined network slice.

16. A communication device according to any one of claims 1 to 15, wherein the sending device sends the message by including information representing the validity period of the network slice set by the message in the message.

17. A control method performed by a communication device, the communication device operating as an IAB node in a relay transmission network compliant with an Integrated Access and Backhaul (IAB) regulation, the IAB node being connected to one of an IAB donor and a communication path formed by the IAB donor, the control method comprising: A message is sent to enable the IAB node connected to the communication path to set up a network slice.

18. A program for causing a computer to function as each of the means in the communication device according to any one of claims 1 to 16.

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