Control node of mobile communication network and computer readable storage medium

Abstract

A control node according to the present invention comprises a transmission means configured so as to transmit, to a first node: speed information indicating the transmission speed between a unit associated with a wireless device and one access point among one or more access points associated with the wireless device; and quantity information indicating the number of the one or more access points associated with the wireless device.

Description

Control node of a mobile communication network and computer-readable storage medium

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

[0002] The RAN of a mobile communication network is composed of a central unit (CU), distributed units (DU), radio units (RU), etc. The RU has the function of transmitting and receiving radio signals to and from a wireless 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] RUs are deployed in a distributed manner in a geographical area to cover the geographical area served by a mobile communication network. On the other hand, DUs and CUs are deployed in fewer communication stations than RUs. Generally, communication stations are classified into "edge sites" that house multiple RUs deployed in a geographically distributed manner, and "central sites" that house multiple edge sites. Patent Document 1 discloses various deployment patterns of DUs and CUs at edge sites and central sites.

[0004] Furthermore, Patent Document 2 discloses a cell-free massive MIMO (CF-m MIMO) technology, which is a coherent interference suppression technology. In CF-m MIMO, the function that transmits and receives wireless signals to and from WDs, i.e., the function equivalent to the RU described above, is called an access point (AP). Therefore, in the following description, the term AP is used instead of the term RU. CF-m MIMO is a communication technology that performs MIMO communication using multiple APs in communication with one WD. In CF-m MIMO, one or more APs are selected for use in communication with one WD. The set of one or more APs used in communication with this one WD is called a "cluster" associated with the WD or the "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 a WD based on a signal addressed to that WD received from the CU. The downlink channel characteristics between the WD and each AP of the cluster associated with that 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 the 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 that WD. Similarly, in the uplink direction, the wireless signal transmitted by the WD is received by each AP of the cluster associated with that 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 that WD. Note that this determination uses the uplink channel characteristics between the WD and each AP of the cluster associated with that WD. In this way, in CF-m MIMO, 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 WD cluster.

[0007] JP 2020-136787 A JP 2023-81600 A

[0008] Using network virtualization technology, the CU and DU can be realized by running appropriate programs on general-purpose computers rather than dedicated hardware. In such cases, one or more computers (hereinafter referred to as a computer group or computer set) are placed at an edge site or a central site, and the CU and DU are virtually realized in each computer group.

[0009] FIG. 1 shows the configuration of a RAN when network virtualization technology is used. A computer group 61 is located at a central site 41, and a computer group 62 is located at an edge site 42. The computer group 61 at the central site 41 is connected to each of the computer groups 62 at multiple edge sites 42 via a transmission path 7. The transmission path 7 may be a wired transmission path or a wireless transmission path. Note that in FIG. 1, the number of edge sites 42 accommodated by one central site 41 is three, but this is an example; the number of edge sites 42 accommodated by one central site 41 may be any number greater than or equal to two. In the following description, when distinguishing between the three edge sites 42, they will be referred to 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 or 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 distinguishing between three AP sets 43, they are referred to as AP set #1, AP set #2, and AP set #3, as shown in FIG. 1 . In FIG. 1 , AP set #1 is accommodated in edge site #1, AP set #2 is accommodated in edge site #2, and AP set #3 is accommodated in edge site #3. The number of APs included in each AP set 43 may vary from one AP set 43 to another.

[0011] Figure 2 shows a state in which two WDs 5 are communicating using CF-m MIMO in the RAN configuration of Figure 1. In the following description, when distinguishing between the two WDs 5, they will be referred to as WD #1 and WD #2 as shown in Figure 2. In Figure 2, the number of APs included in AP set #1 accommodated by the computer group 62 of edge site #1 is set to four. In the following description, when distinguishing between these four APs, they will be referred to as AP #1, AP #2, AP #3, and AP #4 as shown in Figure 2.

[0012] In Figure 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. Furthermore, DU#1 is located in the computer group 62 of edge site #1 for communication with WD#1, and CU#1 is located in the computer group 61 of central site 41. Furthermore, DU#2 is located in the computer group 62 of edge site #1 for communication with WD#2, and CU#2 is located 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. Furthermore, DU#1 generates the 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] 2, the lines connecting the APs and DUs indicate signal paths between functions, not 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 at edge site #1 to AP #3. Similarly, an upstream (UL) signal from AP #3 to DU #1 and an 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 at 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 central site computer group 61 to the edge site computer group 62. 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 edge site computer group 62 to the central site computer group 61.

[0015] 3 illustrates the case where DU #2 accommodating WD #2 is moved from the state illustrated in FIG. 2 to the computer group 61 of the central site 41. As illustrated in FIG. 3, when DU #2 accommodating WD #2 is placed in the computer group 61 of the central site 41, signals transmitted and received between DU #2 and AP #3 and signals transmitted and received between DU #2 and AP #4 are also transmitted over the transmission path 7 connecting the computer group 61 of the central site 41 and the computer group 62 of the edge site #1. Generally, the transmission rate of the DL signal from the CU to the DU is not the same as the transmission rate of the DL signal from the DU to the AP, but the difference is not large. Therefore, if the transmission rate of the DL signal from the CU to the DU and the transmission rate of the DL signal from the DU to the AP are the same value, S, then in FIG. 2, the transmission rate of the DL signal transmitted to WD #2 via the transmission path 7 is S, whereas in FIG. 3, the transmission rate 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, whose signal transmission rate is S and whose cluster contains N APs (N is an integer greater than or equal to 2), is placed at the central site 41, the transmission rate of the transmission path 7 connecting the central site 41 and the edge site 42 increases by (N-1) x S compared to when the DU is placed at the edge site 42. Because the transmission rate of the transmission path 7 has an upper limit, when determining the placement of the DU, it is necessary to ensure that the total transmission rate 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 rate of the transmission path 7 can be minimized, but due to limitations on the 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. Furthermore, as disclosed in Patent Document 1, depending on the type of communication via the WD5, it may be preferable to place the DU at the central site 41.

[0017] According to one aspect of the present disclosure, a wireless access network includes a plurality of access points, a first group of computers connected to the plurality of access points, and a second group of computers connected to the first group of computers via a transmission path, and a wireless device is associated with one or more of the plurality of access points and a unit implemented in the first group of computers or the second group of computers using virtualization technology, and a control node of the 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 transmitting means configured to transmit 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.

[0018] According to the present disclosure, it is possible to appropriately control the placement of units that perform MIMO processing on 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.

[0019] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0020] 1 is a diagram illustrating the configuration of a RAN. 2 is a diagram illustrating an example of communication using CF-mMIMO. 3 is a diagram illustrating an example of communication using CF-mMIMO. 4 is a diagram illustrating a control configuration of a RAN. 5 is a flowchart according to some embodiments. 6 is a flowchart according to some embodiments. 7 is a diagram illustrating the configuration of a control node according to some embodiments. 8 is a diagram illustrating the configuration of a control node according to some embodiments. 9 is a diagram illustrating the configuration of a DU according to some 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 scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be 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 in 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 at a longer cycle 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. The O-RAN Alliance defines an O1 interface that interconnects the SMO1, the Non-RT RIC2, the Near-RT RIC3, ​​and the RAN4. While only one Near-RT RIC3 is shown in FIG. 3, a 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 connected to one Non-RT RIC2 via the A1 interface. In this case, one Near-RT RIC 3 controls the components of the RAN 4 that are present in the corresponding sub-region.

[0024] In this embodiment, the Near-RT RIC 3 determines APs to be included in the cluster of the WDs 5. FIG. 5 is a flowchart of the processing executed by the Near-RT RIC 3. In S10, the Near-RT RIC 3 acquires channel information (channel characteristics) between the WDs 5 and each AP from the RAN 4 via the E2 interface. In S11, the Near-RT RIC 3 determines, for each WD 5, one or more APs to be included in the cluster of the WDs 5, based on the channel information acquired in S10, i.e., determines the cluster of the WDs 5. For example, the Near-RT RIC 3 can determine the cluster of the WDs 5 so as to satisfy the service quality (throughput, error rate, etc.) to be provided to the WDs 5. As will be described later, when the Non-RT RIC 2 notifies the Near-RT RIC 3 of the upper limit of the number of APs that can be included in a cluster of WD5, the Near-RT RIC 3 determines the cluster so that the number of APs to be included in the cluster of WD5 does not exceed the notified upper limit. In the following explanation, the term "cluster size" is used to mean the number of APs in a cluster.

[0025] In S12, the Near-RT RIC 3 notifies the DU accommodating the WD 5 of the cluster determined for that WD 5 via the E2 interface. In S13, for processing in the Non-RT RIC 2 described below, the Near-RT RIC 3 notifies the Non-RT RIC 2 via the A1 interface of "number information" indicating the cluster size of each WD 5 and "speed information" indicating, for each WD 5, the DL and UL transmission speeds S between the WD 5 and one AP of the cluster of that WD 5. The Near-RT RIC 3 repeatedly executes the processing of FIG. 5 in accordance with the control period of the Near-RT RIC 3.

[0026] In this embodiment, the Non-RT RIC 2 determines, for each WD 5, whether the DU accommodating the WD 5 will be placed in the computer group 61 at the central site 41 or the computer group 62 at 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 related to computer resources and a second constraint related to the transmission speed on the transmission path 7.

[0027] First, the first constraint will be described. The first constraint is a condition that the total value of the computer resources required for one or more DUs to be placed in one computer group 62 does not exceed the maximum value of the computer resources available for the DUs in that computer group 62. For this reason, the maximum value of the computer resources available for the DUs is set in advance in the Non-RT RIC 2 for each computer group 62 in each edge site 42. The maximum value of the computer resources available for the DUs may differ for each edge site 42. The Non-RT RIC 2 then determines the DUs to be placed in the computer group 62 in each edge site 42 so that the total value of the computer resources required for one or more DUs to be placed in the computer group 62 does not exceed the maximum value of the computer resources available for the DUs in that 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 this embodiment does not take into consideration the computer group 61 of the central site 41. However, it is also possible to set in advance in the Non-RT RIC2 the maximum value of the computer resources available for DUs in the computer group 61 of the central site 41, and configure the computer resources required for DUs to be placed in the computer group 61 so that they do not exceed the computer resources available for DUs in the computer group 61.

[0029] Next, the second constraint will be described. The second constraint is that the sum of the transmission speeds of the signals for each WD 5 transmitted over the transmission path 7 (hereinafter referred to as the total transmission speed) must not exceed the upper limit speed set for that transmission path 7. For this reason, the Non-RT RIC 2 uses the number information and speed information notified from the Near-RT RIC 3 in S13 of FIG. 5. Note that the processing for the DL direction and the UL direction is similar, so only the DL direction will be described below. The Non-RT RIC 2 is preset with an upper limit speed for the DL direction for each transmission path 7 connecting the central site 41 and 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 if a DU accommodating that WD5 is placed at an edge site, the total transmission speed over the transmission path 7 will increase by S, and if a DU accommodating that WD5 is placed at a central site, the total transmission speed over the transmission path 7 will increase by S x N. Then, the Non-RT RIC2 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 mentioned above, the transmission rate between the DU and the CU and the transmission rate between the DU and the AP are not strictly the same. Therefore, a configuration may be adopted in which it is determined that placing a DU containing a WD 5 at an edge site increases the total transmission rate on the DL transmission path 7 by S × α. α is an adjustment coefficient preset in the Non-RT RIC 2. One DU performs processing in both the DL and UL directions. In other words, it is not possible to place a DU performing DL processing at the edge site 42 and a DU performing UL processing at the central site 41, or to place a DU performing UL processing at the edge site 42 and a DU performing DL processing at the central site 41. Therefore, a DU placement that satisfies the second constraint must be one in which the total transmission rate in both the DL and UL directions does not exceed the upper limit rate.

[0032] 6 is a flowchart of the processing executed by the Non-RT RIC2. ​​The Non-RT RIC2 repeatedly executes the processing of FIG. 6 in accordance with its control cycle. 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 DU placement and the upper limit of the cluster size of each WD5 so as to satisfy the "constraint conditions." Note that, because the control cycle of the Non-RT RIC2 is longer than the control cycle of the Near-RT RIC3, ​​it is possible that the number information and speed information for the same WD5 may be received multiple times between the determination of the DU placement in the previous S21 and the execution of the next S21 processing. In such a case, the Non-RT RIC 2 uses the latest number information and speed information for the WD 5 in the next step S21.

[0033] In S22, the Non-RT RIC2 notifies the SMO1 of the determined DU placement 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 DU placement is achieved.

[0034] In addition, in S23, the Non-RT RIC 2 notifies the Near-RT RIC 3 via the A1 interface of the identifier of the DU accommodating the WD 5 and the upper limit value of the cluster size for each WD 5. By notifying the Near-RT RIC 3 of the identifier of the DU accommodating the WD 5, the DU accommodating the WD 5 can be changed from the edge site 42 to the central site 41, or from the central site 41 to the edge site 42. In addition, when determining the APs 43 to be included in the cluster of the WD 5, the Near-RT RIC 3 ensures that the upper limit value of the cluster size for that WD 5 last notified by the Non-RT RIC 2 is not exceeded.

[0035] The Non-RT RIC 2 can be configured to basically place a DU at the edge site 42, and if such placement does not satisfy the first constraint, 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 RIC 2 can be configured to move to the central site 41 a DU that will result in the smallest increase in the total transmission speed on the transmission path 7 when moved to the central site 41.

[0036] Furthermore, if the type of communication service provided to WD5 requires that the DU accommodating WD5 be placed at the central site 41, the DU for WD5 can be configured to be placed at the central site 41. Furthermore, for example, in the configuration of FIG. 1 , if WD5 is moving from the area of ​​AP set #1 to the area of ​​AP set #2, placing the DU accommodating WD5 at the central site 41 allows a cluster for WD5 to be formed by mixing APs from AP set #1 and APs from AP set #2, and enables necessary services to be provided to WD5 even when moving across edge sites 42. In such a case, the DU accommodating WD5 should also be placed at the central site 41. In this way, a configuration can be adopted in which constraints on the placement location of the DU based on the type of communication service provided and the state of WD5 are considered as third constraints. The constraints on the placement location of the DU based on the third constraint include the constraint that the DU should be placed at the central site 41 and the constraint that the DU should be placed at 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 the second constraint is not satisfied when the remaining DUs, excluding the DU whose placement position is determined by the third constraint, are placed at the edge site 42.

[0037] Furthermore, the Non-RT RIC 2 can be configured to first determine whether a DU should be placed at an edge site 42 or a central site 41, and if the total transmission rate at that time is smaller than the upper limit rate but the difference is within a threshold, assign the cluster size of each WD 5 at that time as the upper limit value of the cluster size to each WD 5. On the other hand, if the total transmission rate is smaller than the upper limit rate and the difference is greater than the threshold, an upper limit value larger than the cluster size of at least one WD 5 can be assigned to that WD 5. Furthermore, if the second constraint is not satisfied in any of the DU placement patterns that satisfy the first constraint or the first and third constraints, the Non-RT RIC 2 can assign the current cluster size of at least one WD 5, i.e., an upper limit value smaller than the cluster size determined by the Near-RT RIC 3, to satisfy the second constraint.

[0038] 5, the Near-RT RIC 3 notifies the Non-RT RIC 2 of the number and speed information of each WD 5. However, a configuration is also possible in which each DU implemented in each computer group 61, 62 repeatedly transmits the number and speed information of the WD 5 it accommodates to the Non-RT RIC 2 via the O1 interface. In this case, S13 in FIG. 5 is omitted.

[0039] For example, if the computer resources of the computer group 62 are sufficiently large, the configuration may be such that the first constraint is not taken into consideration. In this case, the Non-RT RIC 2 determines the DU placement and the upper limit of the cluster size of the WD 5 so as to satisfy only the second constraint, or so as to satisfy both the second and third constraints.

[0040] Second Embodiment Next, the second embodiment will be described, focusing on the differences from the first embodiment. In the first embodiment, the Near-RT RIC 3 determined the cluster of each WD 5. In this embodiment, the cluster of each WD 5 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 MIMO processing on signals from the CU to transmit signals to each AP of the cluster, and performs MIMO processing on received signals from each AP of the cluster to determine the signal to transmit to the CU. Therefore, in this embodiment, the flowchart of FIG. 5 is the processing performed by the DU-C. In this case, S12 in FIG. 5 is the processing for notifying the DU-U of the cluster of the WD. Furthermore, the O1 interface is used for the notification in S13 in FIG. 5. Furthermore, the Near-RT RIC 3 in the processing of FIG. 6 is replaced with DU-C. Furthermore, the O1 interface is used for the notification in S23 of FIG.

[0041] <Device Configuration> Figure 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 number information and speed information of each WD 5 from the Near-RT RIC 3 and the computer groups 61 and 62. The placement determination unit 902 determines whether the DU accommodating each WD 5 should be placed in the computer groups 61 and 62 and the upper limit of the cluster size of each WD, so as to satisfy at least the second constraint.

[0042] The communication unit 903 notifies the Near-RT RIC 3 of the placement position of the DU that accommodates the WD 5 and the upper limit of the cluster size for each WD 5 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 WD 5 and the upper limit of the cluster size for each WD 5 via the O1 interface. Furthermore, if the SMO 1 is not included in the control node 90, the communication unit 903 notifies the SMO 1 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 is 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 in accordance with the placement pattern of the DU notified by the placement determination unit 902 to implement the DU.

[0044] 8 is a configuration diagram of a control node 91 according to this embodiment. The control node 91 can be a device that implements the functions of the Near-RT RIC 3 of each of the above embodiments. A communication unit 913 provides an A1 interface, an E2 interface, and an O1 interface. A cluster determination unit 912 determines the cluster of the WD 5. A transmission unit of the communication unit 913 transmits number information and speed information of the WD 5 to the Non-RT RIC 2 via the A1 interface. A RAN control unit 911 controls the RAN 4 via the E2 interface.

[0045] FIG. 9 is a configuration diagram of the DU-C92 according to this embodiment. The communication unit 923 provides the E2 interface and the 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 by the computer groups 91 and 92.

[0046] Note that 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, respectively, having one or more processors, which, when executed by the one or more processors of a device, causes the device to operate as the control nodes 90 and 91. Therefore, according to the present disclosure, there are provided a computer program, which, when executed by the 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 for storing the computer program. Furthermore, according to the present disclosure, there are provided the methods described with reference to Figures 5 and 6, computer programs for causing a device having one or more processors to perform the methods described with reference to Figures 5 and 6, and computer-readable storage media for storing the computer program.

[0047] 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.

[0048] This application claims priority based on Japanese Patent Application No. 2023-163025, filed on September 26, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A control node of a wireless access network comprising: 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, wherein a wireless device is associated with one or more of the plurality of access points and with a unit implemented in the first computer group or the second computer group by virtualization technology, and wherein the control node is a control node of a wireless access network in which a wireless device and the unit associated with the wireless device communicate via the one or more access points associated with the wireless device, and the control node is provided with a transmitting means configured to transmit 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.

2. A control node as described in claim 1, wherein the first node is configured to determine 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. A control node according to claim 1 or 2, wherein the first node is a non-real-time RAN intelligent controller.

4. A control node according to any one of claims 1 to 3, wherein the unit is a distributed unit of a user plane.

5. A control node according to any one of claims 1 to 4, further comprising selection means arranged to select from said plurality of access points said one or more access points for association with said wireless device.

6. A control node according to claim 5, wherein said selection means is further configured to set the number of said one or more access points to be associated with said wireless device to be equal to or less than an upper limit value notified by said first node.

7. A control node according to any one of claims 1 to 6, wherein the control node is a near real-time RAN intelligent controller.

8. A control node according to any one of claims 1 to 6, wherein the control node is a distributed unit of a control plane.

9. A computer-readable storage medium having stored thereon 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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