Control node of mobile communication network and computer program

Abstract

To provide a technique capable of appropriately controlling an arrangement of a unit that performs MIMO processing.SOLUTION: A control node comprises transmission means of transmitting to a first node, speed information indicating a transmission speed between a unit associated with a radio device and one access point in one or more access points associated with the radio device, and number information indicating the number of one or more access points associated with the radio device.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a control technique for a radio access network (RAN) in a mobile communication network. [Background technology]

[0002] The RAN of a mobile communication network is composed of a central unit (CU), distributed units (DUs), radio units (RUs), etc. The RU has the function of transmitting and receiving radio signals to and from the radio device (WD). The DU processes the medium access control (MAC) layer, radio link control (RLC) layer, etc. The CU processes layers higher than those processed by the DU, such as the packet data convergence protocol (PDCP) layer.

[0003] In order to cover a geographical area where services are provided by a mobile communication network, RUs are deployed in a distributed manner in the geographical area. On the other hand, DUs and CUs are deployed in a smaller number of communication stations than RUs. In general, communication stations are classified into "edge sites" that accommodate multiple RUs that are deployed in a geographically distributed manner, and "central sites" that accommodate multiple edge sites. Patent Document 1 discloses various deployment patterns of DUs and CUs at edge sites and central sites.

[0004] Patent Document 2 discloses a cell-free massive MIMO (CF-mMIMO) technology that is a coherent interference suppression technology. In CF-mMIMO, a function that transmits and receives wireless signals to and from a WD, that is, a function that corresponds to the above-mentioned RU, is called an access point (AP). Therefore, the term AP is used in the following description. CF-mMIMO is a communication technology that performs MIMO communication using multiple APs in communication with one WD. In CF-mMIMO, one or more APs to be used in communication with one WD are selected. A set of one or more APs to be used in communication with one WD is called a "cluster" associated with the WD or a "cluster" of the WD.

[0005] In the downlink direction, the DU generates a signal to be transmitted to each AP of the cluster associated with the WD based on a signal addressed to one WD received from the CU. The downlink channel characteristics between the WD and each AP of the cluster associated with the WD are used to generate the signal to be transmitted to each AP. Each AP of the cluster associated with the WD transmits a wireless signal based on a signal received from the DU. The WD determines the signal received by the DU from the CU based on the wireless signal received from each AP of the cluster associated with the WD. Similarly, in the uplink direction, the wireless signal transmitted by the WD is received by each AP of the cluster associated with the WD and transmitted to the DU. The DU determines the signal transmitted by the WD based on the signal received from each AP of the cluster associated with the WD. In this determination, the uplink channel characteristics between the WD and each AP of the cluster associated with the WD are used. In this way, in CF-mMIMO, the DU is a unit that performs MIMO processing.

[0006] Patent Document 2 discloses a configuration for dynamically controlling APs to be included in a cluster of WDs. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2020-136787 A [Patent Document 2] Patent Publication No. 2023-81600 Summary of the Invention [Problem to be solved by the invention]

[0008] With network virtualization technology, CUs and DUs can be realized by running appropriate programs on general-purpose computers, rather than using dedicated hardware. In such cases, one or more computers (hereinafter referred to as computer groups or computer sets) are placed at edge sites or central sites, and CUs and DUs are virtually realized in each computer group.

[0009] FIG. 1 shows a configuration of RAN when using network virtualization technology. A computer group 61 is arranged in a central site 41, and a computer group 62 is arranged in an edge site 42. The computer group 61 in the central site 41 is connected to each of the computer groups 62 in the multiple edge sites 42 by a transmission path 7. The transmission path 7 may be a wired transmission path or a wireless transmission path. In FIG. 1, the number of edge sites 42 accommodated in one central site 41 is three, but this is an example, and the number of edge sites 42 accommodated in one central site 41 may be any number equal to or greater than two. In the following description, when the three edge sites 42 are to be distinguished from one another, they are denoted as edge site #1, edge site #2, and edge site #3 as shown in FIG. 1.

[0010] The computer group 62 of each edge site 42 is connected to each of the multiple APs via a wired transmission path or a wireless transmission path. In the following description, the multiple APs connected to one computer group 62 are collectively referred to as an AP set 43. As shown in FIG. 1, the computer group 62 of each edge site 42 is connected to each AP of one AP set 43. In the following description, when the three AP sets 43 are to be distinguished from one another, they are referred to as AP set #1, AP set #2, and AP set #3 as shown in FIG. 1. In FIG. 1, the AP set #1 is accommodated in the edge site #1, the AP set #2 is accommodated in the edge site #2, and the AP set #3 is accommodated in the edge site #3. The number of APs included in each AP set 43 may differ for each AP set 43.

[0011] Fig. 2 shows a state in which two WD5s are performing communication by CF-mMIMO in the RAN configuration of Fig. 1. In the following description, when the two WD5s need to be distinguished, they are written as WD#1 and WD#2 as shown in Fig. 2. In Fig. 2, the number of APs included in the AP set #1 accommodated by the computer group 62 of the edge site #1 is set to 4. In the following description, when the four APs need to be distinguished, they are written as AP#1, AP#2, AP#3, and AP#4 as shown in Fig. 2.

[0012] In FIG. 2, the cluster of WD#1 includes AP#1, AP#2, and AP#3, and the cluster of WD#2 includes AP#3 and AP#4. In addition, DU#1 is arranged in the computer group 62 of edge site#1 for communication with WD#1, and CU#1 is arranged in the computer group 61 of central site 41. In addition, DU#2 is arranged in the computer group 62 of edge site#1 for communication with WD#2, and CU#2 is arranged in the computer group 61 of central site 41. For example, DU#1 transmits a wireless signal to WD#1 via AP#1, AP#2, and AP#3 based on a signal addressed to WD#1 from CU#1. In addition, DU#1 generates a signal transmitted by WD#1 based on signals received from AP#1, AP#2, and AP#3, and transmits it to CU#1. The same applies to WD#2.

[0013] In addition, in Fig. 2, the lines connecting the APs and DUs indicate signal paths between functions, and do not indicate transmission paths. For example, a downstream (DL) signal from DU#1 to AP#3 and a DL signal from DU#2 to AP#3 are transmitted via the same DL transmission path that transmits signals from the computer group 62 of edge site#1 to AP#3. Similarly, an upstream (UL) signal from AP#3 to DU#1 and a UL signal from AP#3 to DU#2 are transmitted via the same UL transmission path that transmits signals from AP#3 to the computer group 62 of edge site#1.

[0014] 2, the line connecting CU#1 and DU#1 and the line connecting CU#2 and DU#2 indicate signal paths between functions and do not indicate transmission paths. For example, DL signals from CU#1 to DU#1 and DL signals from CU#2 to DU#2 are transmitted via the same DL transmission path 7 that transmits signals from the computer group 61 at the central site to the computer group 62 at the edge site #1. Similarly, UL signals from DU#1 to CU#1 and UL signals from DU#2 to CU#2 are transmitted via the same UL transmission path 7 that transmits signals from the computer group 62 at the edge site #1 to the computer group 61 at the central site.

[0015] FIG. 3 shows a case where DU#2 accommodating WD#2 is moved from the state shown in FIG. 2 to the group of computers 61 of the central site 41. As shown in FIG. 3, when DU#2 accommodating WD#2 is placed in the group of computers 61 of the central site 41, signals transmitted and received by DU#2 and AP#3 and signals transmitted and received by DU#2 and AP#4 are also transmitted on the transmission path 7 connecting the group of computers 61 of the central site 41 and the group of computers 62 of the edge site #1. In general, the transmission speed of the DL signal from the CU to the DU is not the same as the transmission speed of the DL signal from the DU to the AP, but the difference is not large. Therefore, if the transmission speed of the DL signal from the CU to the DU and the transmission speed of the DL signal from the DU to the AP are the same value S, in FIG. 2, the transmission speed of the DL signal transmitted to WD#2 via the transmission path 7 is S, but in FIG. 3, the transmission speed of the DL signal transmitted to WD#2 via the transmission path 7 is 2S. The same applies to the UL direction.

[0016] In this way, when a DU accommodating a WD5 with a signal transmission speed of S and a cluster containing N APs (N is an integer of 2 or more) is placed at the central site 41, the transmission speed of the transmission path 7 connecting the central site 41 and the edge site 42 increases by (N-1)×S compared to when the DU is placed at the edge site 42. Since there is an upper limit to the transmission speed of the transmission path 7, when deciding the placement of the DU, it is necessary to ensure that the total transmission speed of the transmission path 7 does not exceed the upper limit set for the transmission path 7. For example, by placing all DUs at the edge site 42, the total transmission speed of the transmission path 7 can be minimized, but due to the limited computer resources of the computer group 62 at the edge site 42, it may not be possible to place all DUs at the edge site 42. Also, as disclosed in Patent Document 1, it may be preferable to place the DU at the central site 41 depending on the type of communication by the WD5.

[0017] The present disclosure provides a technology for appropriately controlling the placement of units performing MIMO processing in a first computer group that accommodates an AP set and a second computer group that is connected to the first computer group via a transmission path. [Means for solving the problem]

[0018] According to one aspect of the present disclosure, a wireless access network includes a plurality of access points, a first computer group connected to the plurality of access points, and a second computer group connected to the first computer group via a transmission path, and associates one or more of the plurality of access points with a wireless device and a unit implemented in the first computer group or the second computer group by virtualization technology, and a control node of a wireless access network through which the wireless device and the unit associated with the wireless device communicate via the one or more access points associated with the wireless device includes a transmission means for transmitting to the first node speed information indicating a transmission speed between the unit associated with the wireless device and one of the one or more access points associated with the wireless device, and number information indicating the number of the one or more access points associated with the wireless device. Effect of the Invention

[0019] According to the present disclosure, it is possible to appropriately control the placement of units performing MIMO processing in a first computer group that accommodates an AP set and a second computer group that is connected to the first computer group via a transmission path. [Brief description of the drawings]

[0020] [Figure 1] RAN configuration diagram. [Diagram 2] A diagram showing an example of communication using CF-mMIMO. [Diagram 3] A diagram showing an example of communication using CF-mMIMO. [Figure 4] FIG. 2 shows the control configuration of RAN. [Diagram 5] 1 is a flow chart according to some embodiments. [Figure 6] 1 is a flow chart according to some embodiments. [Figure 7] FIG. 2 is a block diagram of a control node according to some embodiments. [Figure 8] FIG. 2 is a block diagram of a control node according to some embodiments. [Figure 9]FIG. 2 is a block diagram of a DU according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined. In addition, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0022] First Embodiment Fig. 4 is a control configuration diagram of the RAN 4 according to this embodiment. The configuration of the RAN 4 is as shown in Fig. 1, and a repeated description will be omitted. The configuration of Fig. 4 is based on the control configuration defined by the Open Radio Access Network (O-RAN) Alliance, and includes a service management and orchestration (SMO) 1, a non-real-time RAN intelligent controller (Non-RT RIC) 2, and a near-real-time RAN intelligent controller (Near-RT RIC) 3. The Near-RT RIC 3 performs short-term control, and the Non-RT RIC 2 performs control in a longer period than the Near-RT RIC 3.

[0023] The interface between the Near-RT RIC3 and the RAN4 is referred to as the E2 interface. The interface between the Non-RT RIC2 and the Near-RT RIC3 is referred to as the A1 interface. The interface between the SMO1 and the Non-RT RIC2 is referred to as the R1 interface. Furthermore, the O-RAN Alliance defines an O1 interface that interconnects the SMO1, the Non-RT RIC2, the Near-RT RIC3, ​​and the RAN4. Although only one Near-RT RIC3 is shown in FIG. 3, the Near-RT RIC3 is provided for each sub-area that divides the geographical area covered by the RAN4. In other words, there may be multiple Near-RT RIC3s that connect to one Non-RT RIC2 via the A1 interface. In this case, one Near-RT RIC3 controls components that exist in the corresponding sub-area among the components of the RAN4.

[0024] In this embodiment, the Near-RT RIC3 determines APs to be included in the cluster of the WD5. FIG. 5 is a flowchart of the process executed by the Near-RT RIC3. In S10, the Near-RT RIC3 acquires channel information (channel characteristics) between the WD5 and each AP from the RAN4 via the E2 interface. In S11, the Near-RT RIC3 determines, for each WD5, one or more APs to be included in the cluster of the WD5, that is, determines the cluster of the WD5, based on the channel information acquired in S10. For example, the Near-RT RIC3 may determine the cluster of the WD5 so as to satisfy the service quality (throughput, error rate, etc.) to be provided to the WD5. Note that, as will be described later, when the upper limit of the number of APs that can be included in the cluster of the WD5 is notified from the Non-RT RIC2, the Near-RT RIC3 determines the cluster so that the number of APs to be included in the cluster of the WD5 does not exceed the notified upper limit. In the following description, the term "cluster size" is used to mean the number of APs in a cluster.

[0025] In S12, the Near-RT RIC3 notifies the DU accommodating the WD5 of the cluster determined for that WD5 via the E2 interface. In S13, the Near-RT RIC3 notifies the Non-RT RIC2 via the A1 interface of "number information" indicating the cluster size of each WD5 and "speed information" indicating, for each WD5, the DL and UL transmission speeds S between the WD5 and one AP of the cluster of that WD5, for processing in the Non-RT RIC2 described below. The Near-RT RIC3 repeatedly executes the processing of FIG. 5 in accordance with the control period of the Near-RT RIC3.

[0026] In this embodiment, the Non-RT RIC 2 determines, for each WD 5, whether the DU accommodating the WD 5 is to be placed in the computer group 61 of the central site 41 or in the computer group 62 of the edge site 42, and the upper limit of the cluster size of each WD 5, so as to satisfy the "constraints." In this embodiment, the constraints include a first constraint on computer resources and a second constraint on the transmission speed on the transmission path 7.

[0027] First, the first constraint condition will be described. The first constraint condition is a condition that the total value of computer resources required for one or more DUs to be placed in one computer group 62 does not exceed the maximum value of computer resources available for the DU in the computer group 62. For this reason, the maximum value of computer resources available for the DU is set in advance in the Non-RT RIC 2 for each computer group 62 of each edge site 42. The maximum value of computer resources available for the DU may differ for each edge site 42. Then, the Non-RT RIC 2 determines the DU to be placed in the computer group 62 of each edge site 42 such that the total value of computer resources required for one or more DUs to be placed in the computer group 62 does not exceed the maximum value of computer resources available for the DU in the computer group 62.

[0028] Generally, the computer resources available for DUs in the computer group 61 of the central site 41 are sufficiently large, so in this embodiment, the computer group 61 of the central site 41 is not taken into consideration. However, it is also possible to set in advance the maximum value of the computer resources available for DUs in the computer group 61 of the central site 41 in the Non-RT RIC2, and configure the computer resources required for DUs placed in the computer group 61 so as not to exceed the computer resources available for DUs in the computer group 61.

[0029] Next, the second constraint condition will be described. The second constraint condition is that the sum of the transmission speeds of the signals for each WD5 transmitted through the transmission path 7 (hereinafter, the total transmission speed) must not exceed the upper limit speed set for the transmission path 7. For this reason, the Non-RT RIC2 uses the number information and speed information notified from the Near-RT RIC3 in S13 of FIG. 5. Note that since the processing in the DL direction and the UL direction is similar, only the DL direction will be described below. In the Non-RT RIC2, an upper limit speed in the DL direction is set in advance for each of the transmission paths 7 connecting the central site 41 and the multiple edge sites 42. Note that the upper limit speed may differ for each edge site 42.

[0030] For example, for a certain WD5, the speed information indicates that the transmission speed of the DL signal is S, and the number information indicates that the cluster size of that WD5 is N. In this case, the Non-RT RIC2 calculates the total transmission speed to each WD5 transmitted over the transmission path 7, assuming that placing the DU accommodating that WD5 at an edge site increases the total transmission speed on the transmission path 7 by S, and placing the DU accommodating that WD5 at a central site increases the total transmission speed on the transmission path 7 by S×N. Then, it determines the placement of the DU and the upper limit of the cluster size of each WD5 so that this total transmission speed does not exceed the upper limit speed of that transmission path 7.

[0031] As described above, the transmission speed between the DU and the CU and the transmission speed between the DU and the AP are not exactly the same, so the configuration may be such that it is determined that the total transmission speed in the DL transmission path 7 increases by S×α when the DU accommodating the WD5 is placed at the edge site. Here, α is an adjustment coefficient that is set in advance in the Non-RT RIC2. ​​One DU processes both the DL direction and the UL direction. In other words, it is not possible to place a DU that processes the DL direction at the edge site 42 and a DU that processes the UL direction at the central site 41, or to place a DU that processes the UL direction at the edge site 42 and a DU that processes the DL direction at the central site 41. Therefore, the placement of the DU that satisfies the second constraint condition needs to be one in which the total transmission speed in both the DL direction and the UL direction does not exceed the upper limit speed in that placement.

[0032] FIG. 6 is a flowchart of the process executed by the Non-RT RIC2. ​​The Non-RT RIC2 repeatedly executes the process of FIG. 6 according to the control cycle of the Non-RT RIC2. ​​In S20, the Non-RT RIC2 stores the number information and speed information of each WD5 notified from the Near-RT RIC3. In S21, the Non-RT RIC2 determines the arrangement of the DUs and the upper limit of the cluster size of each WD5 so as to satisfy the "constraint condition". Since the control cycle of the Non-RT RIC2 is longer than the control cycle of the Near-RT RIC3, ​​it may occur that the number information and speed information of the same WD5 are received multiple times between the determination of the DU arrangement in the previous S21 and the processing of the next S21. In such a case, the Non-RT RIC2 uses the latest number information and speed information of the WD5 in the next S21.

[0033] In S22, the Non-RT RIC2 notifies the SMO1 of the determined placement of the DUs via the R1 interface. Identifiers are assigned to the DUs, and the Non-RT RIC2 can indicate the placement of the DUs to the SMO1 by indicating the identifiers of the DUs to be placed in each of the computer groups 61 and 62. The SMO1 controls the computer group 61 at the central site 41 and the computer group 62 at the edge site 42 via the O1 interface so that the notified placement of the DUs is achieved.

[0034] Furthermore, in S23, the Non-RT RIC2 notifies the Near-RT RIC3 of the identifier of the DU accommodating the WD5 and the upper limit value of the cluster size for each WD5 via the A1 interface. By notifying the Near-RT RIC3 of the identifier of the DU accommodating the WD5, the DU accommodating the WD5 may be changed from the edge site 42 to the central site 41, or from the central site 41 to the edge site 42. Furthermore, when determining the APs 43 to be included in the cluster of the WD5, the Near-RT RIC3 ensures that the upper limit value of the cluster size of the WD5 last notified by the Non-RT RIC2 is not exceeded.

[0035] The Non-RT RIC2 can be configured to basically place a DU at the edge site 42, and if such placement does not satisfy the first constraint condition, select a DU to be moved from the DU placed at the edge site 42 to the central site 41. In this case, the Non-RT RIC2 can be configured to move to the central site 41 a DU that will cause the smallest increase in the total transmission speed on the transmission path 7 when moved to the central site 41.

[0036] In addition, if the DU accommodating the WD5 should be placed in the central site 41 due to the type of communication service provided to the WD5, the DU of the WD5 can be configured to be placed in the central site 41. Furthermore, for example, in the configuration of FIG. 1, if the WD5 is moving from the area of ​​AP set #1 to the area of ​​AP set #2, the DU accommodating the WD5 can be placed in the central site 41 to configure a cluster for the WD5 by mixing APs of AP set #1 and APs of AP set #2, and necessary services can be provided to the WD5 even when it moves across the edge site 42. In such a case, the DU accommodating the WD5 should be placed in the central site 41. In this way, the configuration can be made to consider the constraints on the placement location of the DU due to the type of communication service provided and the state of the WD5 as the third constraint. The constraints on the placement location of the DU due to the third constraint include the constraint that the DU should be placed in the central site 41 and the constraint that the DU should be placed in the edge site 42. In this case, the Non-RT RIC2 may be configured to select a DU to be moved to the central site 41 from the remaining DUs if placing the remaining DUs, excluding the DU whose placement position is determined by the third constraint, at the edge site 42 does not satisfy the second constraint.

[0037] Also, the Non-RT RIC2 can be configured to first determine the placement of the DU at the edge site 42 or the central site 41, and if the total transmission speed at that time is smaller than the upper limit speed but the difference is within a threshold, to assign the cluster size of each WD5 at that time as the upper limit value of the cluster size to each WD5. On the other hand, if the total transmission speed is smaller than the upper limit speed and the difference is greater than the threshold, an upper limit value larger than the cluster size of at least one WD5 can be assigned to that WD5. Furthermore, if the second constraint is not satisfied in all of the placement patterns of DUs that satisfy the first constraint condition or the first and third constraint conditions, the Non-RT RIC2 can assign the current cluster size of at least one WD5, that is, an upper limit value smaller than the cluster size determined by the Near-RT RIC3, ​​to that WD5 so as to satisfy the second constraint condition.

[0038] In S13 of Fig. 5, the Near-RT RIC 3 notifies the Non-RT RIC 2 of the number information and speed information of each WD 5. However, the configuration may be such that each DU implemented in each computer group 61, 62 repeatedly transmits the number information and speed information of the WD 5 accommodated therein to the Non-RT RIC 2 via the O1 interface. In this case, S13 of Fig. 5 is omitted.

[0039] For example, if the computer resources of the computer group 62 are also sufficiently large, the first constraint condition may not be taken into consideration. In this case, the Non-RT RIC2 determines the placement of DUs and the upper limit of the cluster size of the WD5 so as to satisfy only the second constraint condition, or so as to satisfy both the second and third constraint conditions.

[0040] Second Embodiment Next, the second embodiment will be described with a focus on differences from the first embodiment. In the first embodiment, the Near-RT RIC3 determines the cluster of each WD5. In this embodiment, the cluster of each WD5 is determined in the DU (DU-C) of the control plane. The DU-C controls one or more DUs (DU-U) of the user plane. The DU-U performs a process of performing MIMO processing of a signal from the CU to transmit a signal to each AP of the cluster, and a process of performing MIMO processing of a received signal from each AP of the cluster to determine a signal to be transmitted to the CU. Therefore, in this embodiment, the flowchart in FIG. 5 is a process performed by the DU-C. In this case, S12 in FIG. 5 is a process of notifying the DU-U of the cluster of the WD. In addition, the O1 interface is used for the notification in S13 in FIG. 5. In addition, the Near-RT RIC3 in the process in FIG. 6 is replaced with the DU-C. In addition, the O1 interface is used for the notification in S23 in FIG. 6.

[0041] <Device configuration> 7 is a configuration diagram of the control node 90 according to each embodiment. The control node 90 may be a device that implements the functions of the Non-RT RIC2 of each of the above embodiments, or a device that implements the functions of both the Non-RT RIC2 and the SMO1. The communication unit 903 provides an A1 interface, an R1 interface, and an O1 interface. The collection unit 901 collects the number information and speed information of each WD5 from the Near-RT RIC3 and the computer groups 61 and 62. The placement determination unit 902 determines which of the computer groups 61 and 62 the DU that accommodates each WD5 should be placed in, and the upper limit value of the cluster size of each WD, so as to satisfy at least the second constraint condition.

[0042] The communication unit 903 notifies the Near-RT RIC3 of the placement position of the DU that accommodates the WD5 and the upper limit of the cluster size for each WD5 via the A1 interface. Alternatively, the communication unit 903 notifies the computer groups 61 and 62 of the placement position of the DU that accommodates the WD5 and the upper limit of the cluster size for each WD5 via the O1 interface. Also, if the SMO1 is not included in the control node 90, the communication unit 903 notifies the SMO1 of the DU placement pattern via the R1 interface.

[0043] When SMO1 is included in the control node 90, the control node 90 has a computer control unit 904. In this case, the R1 interface becomes an internal interface between the placement determination unit 902 and the computer control unit 904. The computer control unit 904 controls the computer groups 61 and 62 according to the placement pattern of the DU notified by the placement determination unit 902 to implement the DU.

[0044] 8 is a configuration diagram of the control node 91 according to this embodiment. The control node 91 may be a device that implements the functions of the Near-RT RIC3 of each of the above embodiments. The communication unit 913 provides an A1 interface, an E2 interface, and an O1 interface. The cluster determination unit 912 determines the cluster of the WD5. The transmission unit of the communication unit 913 transmits the number information and speed information of the WD5 to the Non-RT RIC2 via the A1 interface. The RAN control unit 911 controls the RAN4 via the E2 interface.

[0045] Fig. 9 is a configuration diagram of the DU-C92 according to this embodiment. The communication unit 923 provides an E2 interface and an O1 interface. The cluster determination unit 921 determines the cluster of the WD5. The transmission unit of the communication unit 923 transmits the number information and speed information of the WD5 to the Non-RT RIC2 via the O1 interface. The control unit 921 controls the DU-U. Note that Fig. 9 can also be regarded as a configuration diagram of the functions realized in the computer groups 91 and 92.

[0046] The control nodes 90 and 91 according to the present disclosure may be configured by a plurality of devices capable of communicating with each other via a network. Furthermore, the control nodes 90 and 91 may be realized by a computer program that, when executed by one or more processors of a device having one or more processors, causes the device to operate as the control nodes 90 and 91, respectively. Thus, according to the present disclosure, there is provided a computer program that, when executed by one or more processors of a device having one or more processors, causes the device to operate as the control nodes 90 and 91, and a computer-readable storage medium that stores the computer program.

[0047] According to this embodiment, it is possible to appropriately control the placement of units performing MIMO processing on the first computer group that houses the AP set and the second computer group that is connected to the first computer group via a transmission line. Therefore, it is possible to contribute to Goal 9 of the Sustainable Development Goals (SDGs) led by the United Nations, "Build resilient infrastructure, promote sustainable industrialization, and foster innovation."

[0048] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0049] 913, 923: Communications Department

Claims

1. Multiple access points; a first group of computers connected to the plurality of access points; a second group of computers connected to the first group of computers via a transmission line; Equipped with Associating one or more of the plurality of access points with a wireless device and a unit implemented in the first computer group or the second computer group by a virtualization technique; A control node of a radio access network in which a radio device and the unit associated with the radio device communicate via the one or more access points associated with the radio device, A control node comprising a transmitting means for transmitting to a first node speed information indicating a transmission speed between the unit associated with the wireless device and one of the one or more access points associated with the wireless device, and number information indicating the number of the one or more access points associated with the wireless device.

2. The control node of claim 1 , wherein the first node determines whether the unit associated with the wireless device is to be implemented in the first group of computers or the second group of computers.

3. The control node of claim 1 , wherein the first node is a non-real-time RAN intelligent controller.

4. The control node of claim 1 , wherein the unit is a distributed unit of a user plane.

5. The control node of claim 1 , further comprising: a selection means for selecting the one or more access points from the plurality of access points for association with the wireless device.

6. 6. The control node according to claim 5, wherein said selection means sets the number of said one or more access points to be associated with said wireless device to an upper limit value notified by said first node or less.

7. The control node of claim 1 , wherein the control node is a near real-time RAN intelligent controller.

8. The control node of claim 1 , wherein the control node is a distributed unit of a control plane.

9. A computer program comprising instructions that, when executed on one or more processors of an apparatus having one or more processors, cause the apparatus to function as a control node according to any one of claims 1 to 8.

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