JP7617804B2 - Base station function allocation control device, base station function allocation control method, and computer program - Google Patents

Description

The present invention relates to a base station function arrangement control device, a base station function arrangement control method, and a computer program.

In the fifth generation (5G) mobile communication system (hereinafter referred to as the 5G system), studies are being conducted to further improve performance, such as throughput, communication delay, and number of connections, from the initial system. In addition, a wide variety of services, such as robot control, connected cars, AR (Augmented Reality), and VR (Virtual Reality), are being provided using the 5G system, and it is becoming increasingly important to meet the communication quality required by each service.

Radio Access Network (RAN) slicing technology is known as a wireless communication technology that satisfies the communication quality required by such diversifying services. RAN slicing technology divides the RAN into multiple logical networks (slices) and flexibly customizes the slices according to the service (see, for example, Patent Document 1).

According to RAN slicing technology, for example, by changing the arrangement of CU (Central Unit) and DU (Distributed Unit), which are base station functions, communication delay, inter-cell coordination performance, and required network resources (radio resources, computer resources, and transmission path resources) change. For this reason, the technology described in Patent Document 1 realizes slicing of multiple different base station function arrangements for a single cell by connecting multiple sets of vCU (Virtual CU) and vDU (Virtual DU) to an RU (Radio Unit) that forms a single cell.

The O-RAN (Open Radio Access Network) Alliance is also considering opening up and making intelligent next-generation radio access networks such as 5G systems (see, for example, Non-Patent Document 1). Among the O-RAN specifications formulated by the O-RAN Alliance, Non-Patent Document 1 specifies a use case in which a "Non-RT RIC (Non-Real Time RAN Intelligent Controller)" is used to optimize a Network Slice Subnet Instance (NSSI) in response to traffic fluctuations.

In the use case of Non-Patent Document 1, Non-RT RIC collects the required KPIs (Key Performance Indicators) from each node via the O1 interface. The parameters that can be collected via the O1 interface correspond to the parameters defined in Non-Patent Document 2. For example, these parameters include DL PRB usage, UL PRB usage, Average DL UE throughput, Average UL UE throughput, and Number of PDU Sessions requested. Non-RT RIC analyzes the collected information and determines how to change resources related to NSSI. For example, it changes "VNF resources" and "slice subnet attributes" (see Non-Patent Document 3). Non-RT RIC changes the settings of resources related to NSSI for each node via the O1 interface.

In addition, methods using deep reinforcement learning are being considered for network control that takes into account various parameters. Deep reinforcement learning is a machine learning method that learns optimal behavior (control) through trial and error in the environment to be controlled. Furthermore, in recent years, distributed learning (distributed reinforcement learning) in deep reinforcement learning has attracted attention in order to improve learning efficiency. For example, in "Ape-X", a method of distributed reinforcement learning, multiple "Actors" each collect experience (learning data) through trial and error with the environment, and this is learned by the "Learner". The learning model of the "Actor" is regularly updated by the "Learner". By processing multiple "Actors" in parallel, it is possible to efficiently learn various data.

Non-Patent Document 4 describes a wireless resource allocation control technology that uses distributed reinforcement learning. In the wireless resource allocation control technology described in Non-Patent Document 4, each "Actor" optimally controls the wireless resource allocation of each slice, thereby satisfying the user's required quality with a small number of wireless resources.

JP 2020-136787 A

O-RAN WG1, “Slicing architecture”, v03.00, 3.2.3 Use Case 3: NSSI Resource Allocation Optimization 3GPP, “TS 28.552”, V17.1.0, 2020-12 3GPP, “TS 28.541”, V15.4.0, 2019-09 Yu Abiko, et al., “Flexible Resource Block Allocation to Multiple Slices for Radio Access Network Slicing Using Deep Reinforcement Learning”, IEEE Access, vol. 8, pp. 68183-68198, Apr. 2020.

Since traffic demand in the RAN changes dynamically, the traffic flowing through each slice also changes dynamically. Fluctuations in traffic also cause fluctuations in the bandwidth required for the transmission path and the computer resources of the antenna site and the accommodating station. For this reason, in order to meet the quality requirements of many users with limited network resources, it is preferable to adaptively change the placement of base station functions in the RAN in response to traffic fluctuations.

When applying distributed reinforcement learning to base station function allocation, it is conceivable that each "Actor" controls the base station function allocation (mapping of slices and base station functions) for each cell. When deciding the base station function allocation, the transmission paths shared between cells, the computer resources of the accommodating stations, and the presence or absence of inter-cell cooperation vary depending on the base station function allocation for each cell, so it is preferable to determine the base station function allocation for each cell so as to maximize the quality required by users across the entire RAN.

However, in distributed reinforcement learning, "actors" act independently and do not take into account the actions of other "actors." Therefore, if each actor simultaneously performs an action (change in base station function allocation) as in the past, it is difficult to optimize the base station function allocation across the entire RAN. For example, if base station functions are allocated so that all cells consume a lot of transmission line bandwidth just because the transmission line bandwidth is available, the transmission line will become congested. Furthermore, if congestion occurs due to fluctuations in traffic demand, the congestion will continue until the next time the base station function allocation is changed. For this reason, the challenge is to appropriately control the execution of base station function allocation.

The present invention was made in consideration of these circumstances, and its purpose is to appropriately control the execution of base station function placement in an O-RAN-specification radio access network.

(1) One aspect of the present invention is a base station function arrangement control device comprising: a cell group information storage unit that stores cell group information indicating a cell group to which a plurality of cells included in an O-RAN radio access network belong; and a control unit that shifts a timing of changing a base station function arrangement for each cell belonging to one of the cell groups, wherein the cell group is composed of a plurality of cells that share the same transmission path, the transmission path being a transmission path between an accommodation station and an antenna site, and a required bandwidth of the transmission path differs depending on the base station function arrangement, and the control unit sequentially changes the base station function arrangement in the plurality of cells so as to avoid congestion based on an observed value of an overall bandwidth utilization rate of the transmission path shared by a plurality of cells belonging to the same cell group.
( 2 ) One aspect of the present invention is the base station function arrangement control device according to (1) above, wherein the cell group is composed of a plurality of cells that satisfy a predetermined radio wave influence standard.
( 3 ) One aspect of the present invention is the base station function arrangement control device according to ( 2 ) above, wherein the radio wave influence criterion is that the cell interval is within a predetermined distance.
( 4 ) One aspect of the present invention is the base station function arrangement control device according to ( 2 ) above, wherein the radio wave influence standard is that the influence of radio waves is equal to or greater than a predetermined standard.
( 5 ) One aspect of the present invention is a base station function arrangement control device of any of (1) to ( 4 ) above, in which the control unit determines base station function arrangement for each cell included in the radio access network by distributed reinforcement learning.
( 6 ) One aspect of the present invention is a base station function arrangement control device according to any one of (1) to ( 5 ) above, which is realized using a “Non-RT RIC (Non-Real Time RAN Intelligent Controller).”

( 7 ) One aspect of the present invention is a base station function arrangement control method in an O-RAN radio access network, comprising: a cell group information storage step in which a base station function arrangement control device stores cell group information indicating a cell group to which a plurality of cells included in the O-RAN radio access network belong; and a control step in which the base station function arrangement control device staggers an arrangement change timing at which the base station function arrangement is changed for each cell belonging to one of the cell groups , wherein the cell group is composed of a plurality of cells sharing the same transmission path, the transmission path being a transmission path between an accommodation station and an antenna site, and a required bandwidth of the transmission path differs depending on the base station function arrangement, and the control step sequentially changes the base station function arrangement in the plurality of cells so as to avoid congestion based on an observed value of an overall bandwidth utilization rate of the transmission path shared by a plurality of cells belonging to the same cell group .

(8) One aspect of the present invention is a computer program that causes a computer of a base station function layout control device to execute a cell group information storage step of storing cell group information indicating a cell group to which a plurality of cells included in a radio access network of O-RAN specifications belong, and a control step of shifting a layout change timing of changing the base station function layout for each cell belonging to one of the cell groups , wherein the cell group is composed of a plurality of cells that share the same transmission path, the transmission path is a transmission path between an accommodation station and an antenna site, and the required bandwidth of the transmission path differs depending on the base station function layout, and the control step sequentially changes the base station function layout in the plurality of cells so as to avoid congestion based on an observed value of an overall bandwidth utilization rate of the transmission path shared by a plurality of cells belonging to the same cell group.

The present invention has the advantage of being able to appropriately control the execution of base station function placement in an O-RAN-specification radio access network.

FIG. 2 is a block diagram showing an example of the configuration of a radio access network according to an embodiment. FIG. 2 is an explanatory diagram showing an example of a base station function arrangement in a RAN according to one embodiment. 2 is a block diagram showing an example of the configuration of a base station function arrangement control unit according to an embodiment; FIG. FIG. 11 is a diagram illustrating an example of the configuration of cell group information according to an embodiment. FIG. 11 is an explanatory diagram of a timing for changing a layout according to an embodiment. FIG. 4 is a block diagram showing an example of the configuration of a control unit according to an embodiment. 1 is a flowchart showing an outline of a base station function arrangement control method according to an embodiment. 1 is a sequence diagram showing an example of a detailed procedure of a base station function arrangement control method according to an embodiment. FIG. 1 is an explanatory diagram of an example 1 of a cell group determination method according to an embodiment. FIG. 1 is an explanatory diagram of an example 1 of a cell group determination method according to an embodiment. FIG. 11 is an explanatory diagram of an example 2 of a cell group determination method according to an embodiment. FIG. 11 is an explanatory diagram of an example 2 of a cell group determination method according to an embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Fig. 1 is a block diagram showing a configuration example of a radio access network according to an embodiment. The radio access network (RAN) 1 shown in Fig. 1 is a RAN to which RAN slicing technology is applied. In addition, the O-RAN specification is applied to the RAN 1.

Figure 2 shows an example of the base station function arrangement of RAN1. In the example of Figure 2, a total of five sets of vCU and vDU are connected to the RU that forms a single cell. The first example, "O-RAN slice subnet #1", is a C-RAN (Centralized -RAN) arrangement, in which both the vCU and vDU are arranged in the accommodating station. The C-RAN arrangement is characterized by the fact that inter-cell cooperation is possible, but the required bandwidth of the transmission path is large. The second example, "O-RAN slice subnet #2" and the third example, "O-RAN slice subnet #3", are S-RAN (Split -RAN) arrangements, in which the vDU is arranged in the antenna site and the vCU is arranged in the accommodating station. The S-RAN arrangement is characterized by the fact that inter-cell cooperation is not possible, but the required bandwidth of the transmission path is small. The fourth example, "O-RAN slice subnet #4," and the fifth example, "O-RAN slice subnet #5," are D-RAN (Distributed RAN) deployments in which both a vCU and a vDU are deployed at an antenna site. D-RAN deployments do not allow inter-cell coordination, but have the characteristic of small communication delays.

As illustrated in FIG. 2, in RAN1, by connecting multiple sets of vCUs and vDUs to an RU forming a single cell, it is possible to realize slices of base station function arrangements with multiple different characteristics for a single cell. This makes it possible to provide wireless communication services with multiple different characteristics in a single cell in RAN1, and to adapt to the various communication qualities required by a wide variety of services.

In FIG. 1, RAN 1 includes an SMO (Service and Management Orchestration) function unit (SMO Functions) 11, a "Non-RT RIC (Non-real-time RAN Intelligent Controller)" 12 including a base station function placement control unit 20, and a base station function group 2. The base station function placement control unit 20 corresponds to a base station function placement control device. In this embodiment, the base station function placement control unit 20 is realized using the "Non-RT RIC" 12. Furthermore, the SMO function unit 11 and the "Non-RT RIC" 12 are realized using an SMO framework 10. The base station function group 2 is composed of an RU, a vCU, and a vDU, as illustrated in FIG. 2.

The SMO framework 10 provides the O1 interface defined in the O-RAN specifications. The "Non-RT RIC" 12 obtains KPIs (key performance indicators) from the base station function group 2 via the O1 interface.

The SMO function unit 11 and the "Non-RT RIC" 12 exchange messages via the interface 100. The interface 100 is an interface between the SMO function unit 11.

Figure 3 is a block diagram showing an example of the configuration of the base station function placement control unit 20 according to this embodiment. In Figure 3, the base station function placement control unit 20 includes a cell group information storage unit 220, a KPI acquisition unit 203, a base station function placement setting information transmission unit 204, and a control unit 205.

The functions of each part of the base station function placement control unit 20 are realized by the CPU executing a computer program for realizing the function of each part.

The cell group information storage unit 220 stores cell group information. The cell group information is information indicating the cell group to which multiple cells included in RAN1 belong.

Figure 4 shows an example of the configuration of cell group information stored in the cell group information storage unit 220. In Figure 4, the cell group information stores an identifier (cell ID) that is associated with a cell group identifier (group ID) and identifies a cell that belongs to the cell group of the group ID.

The KPI acquisition unit 203 acquires KPIs from the base station function group 2 via the O1 interface. The KPIs acquired by the KPI acquisition unit 203 from the base station function group 2 include, for example, the throughput of each service, the utilization rate of wireless resources, the utilization rate of computer resources, the utilization rate of transmission line bandwidth, etc.

The base station function layout setting information transmission unit 204 transmits the base station function layout setting information via the interface 100 between the SMO function unit 11. The base station function layout setting information is information indicating the changes to be made to the base station function layout in order to change the base station function layout in RAN1.

The control unit 205 determines the next base station function placement for each cell based on the KPIs acquired by the KPI acquisition unit 203. The control unit 205 shifts the timing for changing the base station function placement (placement change timing) for each cell belonging to a cell group included in the cell group information stored in the cell group information storage unit 220.

Figure 5 is an explanatory diagram of the placement change timing according to this embodiment. In the example of Figure 5, the placement change timing for one cell group consisting of three cells (Cell #1, Cell #2, Cell #3) is shown. In Figure 5, a period (placement execution period) T for executing base station function placement is set. The control unit 205 determines the placement change timing for each cell (Cell #1, Cell #2, Cell #3) based on the placement execution period T. Specifically, for the first cell (Cell #1), the timing of the placement execution period T is the placement change timing. For the second cell (Cell #2), the timing shifted backward by the shift width ΔT from the placement change timing of the first cell (Cell #1) is the placement change timing. For the third cell (Cell #3), the timing shifted backward by the shift width ΔT from the placement change timing of the second cell (Cell #2) is the placement change timing. In the example of FIG. 5, the shift width ΔT is "ΔT = T ÷ m, where m is the total number of cells in the cell group," which is "ΔT = T ÷ 3." In other words, in the example of FIG. 5, the timing of the placement change of each cell is shifted evenly.

As shown in FIG. 5, by shifting the timing of the relocation of each cell so that they do not overlap, the change in the network state (e.g., KPI) caused by the change in the base station function layout for one cell can be reflected in the change in the base station function layout for the next cell. For example, when the base station function layout for the first cell (Cell #1) is changed, the KPI for the second cell (Cell #2) changes due to the change in the base station function layout. Here, since the timing of the relocation of the second cell (Cell #2) is shifted back by the shift width ΔT from the timing of the relocation of the first cell (Cell #1), the next base station function layout for the second cell (Cell #2) is determined based on the KPI after the change. As a result, the change in the base station function layout for the second cell (Cell #2) can be changed to reflect the change in the KPI caused by the change in the base station function layout for the first cell (Cell #1).

Fig. 6 is a block diagram showing an example of the configuration of the control unit according to this embodiment. In Fig. 6, the control unit 205 determines the base station function allocation for each cell included in RAN1 by distributed reinforcement learning. RAN1 includes a plurality of cells (Cell #1, Cell #2, ..., Cell #n). The control unit 205 includes a plurality of "Actors" 301 (Actor #1, Actor #2, ..., Actor #n) respectively corresponding to the plurality of cells (Cell #1, Cell #2, ..., Cell #n), a "Repository" 302, and a "Learner" 303.

Each "Actor" 301 collects "Experiences" (learning data) through trial and error with the cell (environment) based on the KPIs obtained from the cell it is responsible for. The "Repository" 302 stores the learning data collected by each "Actor" 301. The "Learner" 303 uses the learning data stored in the "Repository" 302 to learn a base station function placement learning model. The base station function placement learning model of each "Actor" 301 is periodically updated by the "Learner" 303. A certain "Actor" 301 uses the base station function placement learning model to optimize the base station function placement in the cell that the "Actor" 301 is responsible for.

The control unit 205 uses each "Actor" 301 (Actor #1, Actor #2, ..., Actor #n) to find an optimal solution for the allocation of base station functions in each cell (Cell #1, Cell #2, ..., Cell #n). At this time, the control unit 205 determines an order (cell order) indicating from which cell the optimal solution for the allocation of base station functions is to be found for each cell group for multiple cells (Cell #1, Cell #2, ..., Cell #n), and finds the optimal solution for the allocation of base station functions according to the cell order.

Next, the overall procedure of the base station function placement control method according to this embodiment will be described with reference to FIG. 7. FIG. 7 is a flowchart showing the outline of the procedure of the base station function placement control method according to this embodiment.

(Step S11) The base station function deployment control unit 20 (control unit 205) determines a cell group for multiple cells (Cell #1, Cell #2, ..., Cell #n) based on the cell group information in the cell group information storage unit 220.

(Step S12) The base station function deployment control unit 20 (control unit 205) determines the order of cells for each cell group for multiple cells (Cell #1, Cell #2, ..., Cell #n).

Next, base station function allocation is performed for each cell (Cell #1, Cell #2, ..., Cell #n) in the order of cells in each cell group determined in step S12. For example, base station function allocation may be performed for cells in the same cell group, one cell group at a time, in the order of cells in the cell group. For example, base station function allocation may be performed for cells in the same cell group, in the order of cells, in each cell group. For convenience, the order is shown in Figure 5 as Cell #1, Cell #2, ..., Cell #n.

Steps S13 and S14 are executed to execute the base station function allocation for the cell. Here, the execution of base station function allocation is explained using "Cell #1" as an example, but the same applies to other cells.

(Step S13) The base station function deployment control unit 20 (KPI acquisition unit 203) acquires KPIs from "Cell #1".

(Step S14) The base station function placement control unit 20 (control unit 205) determines the next base station function placement in "Cell #1" based on the KPI acquired from "Cell #1". The base station function placement control unit 20 (control unit 205) generates base station function placement setting information regarding the determined next base station function placement in "Cell #1". The base station function placement setting information is information indicating the changes to the base station function placement for changing the base station function placement in "Cell #1" to the next base station function placement.

Then, the base station function layout control unit 20 (base station function layout setting information transmission unit 204) transmits the base station function layout setting information for "Cell #1" generated by the control unit 205 to the SMO function unit 11. Next, the SMO function unit 11 executes settings to change the base station function layout of "Cell #1" in base station function group 2 based on the base station function layout setting information for "Cell #1". As a result, the base station function layout of "Cell #1" in base station function group 2 is changed to the next base station function layout.

Next, the detailed steps of the base station function placement control method according to this embodiment will be described with reference to FIG. 8. FIG. 8 is a sequence diagram showing an example of the detailed steps of the base station function placement control method according to this embodiment.

(Step S201) The base station function deployment control unit 20 determines the execution order of base station function deployment (cell order) for each cell group.

(Step S202) Next, the base station function arrangement control unit 20 receives a "Performance measurements" message from each node (O-CU, O-DU1, O-DUN) of the base station function group 2 via the O1 interface. The base station function arrangement control unit 20 acquires the KPI from the "Performance measurements" message.

(Step S203) Next, the base station function placement control unit 20 determines the next base station function placement for each cell according to the cell order determined in step S201, based on the KPIs acquired from the "Performance measurements" message. The base station function placement control unit 20 generates base station function placement setting information regarding the next base station function placement for each determined cell.

Next, steps S204 to S205 are executed as a sequence for changing the base station function settings. This sequence for changing the base station function settings is based on the O-RAN specification "Reconfiguration of O-RAN Virtual Network Function(s) (O-RAN.WG6.ORCH-USE-CASES-v01.00)."

Steps S204 and S205 are executed for each cell group in the order of the cells. Here, after steps S204 and S205 are executed for one cell in the same cell group, the process returns to step S202, the next base station function arrangement is determined for the next cell in the order of the cell, and steps S204 and S205 are executed for the next cell. In this way, the process of steps S202-S205 is repeated for each cell in the same cell group in the order of the cells.

(Step S204) The base station function layout control unit 20 transmits a "Reconfig NF set" message including the base station function layout setting information generated in step S203 to the SMO function unit 11 via the interface 100. The SMO function unit 11 acquires the base station function layout setting information from the "Reconfig NF set" message received via the interface 100.

(Step S205) The SMO function unit 11 sends a "Configure NF" message to each node (O-CU, O-DU1, O-DUN) in the base station function group 2 via the O1 interface. This "Configure NF" message contains setting information for changing to the next base station function arrangement indicated in the base station function arrangement setting information acquired in step S204. As a result, the base station function arrangement of the cell in the base station function group 2 is changed to the next base station function arrangement of the cell.

Next, we will explain the cell group determination method according to this embodiment.

(Example 1 of cell group determination method)
9 is an explanatory diagram of an example 1 of a cell group determination method according to the present embodiment. In the example 1 of the cell group determination method, a cell group is composed of a plurality of cells sharing the same transmission path. The shared transmission path is, for example, a transmission path between an accommodation station and an antenna site.

The required bandwidth of the transmission path varies depending on the base station function layout. Specifically, a C-RAN layout requires a large bandwidth of the transmission path, an S-RAN layout requires a medium-large bandwidth of the transmission path, and a D-RAN layout requires a small bandwidth of the transmission path. For this reason, when a transmission path between a accommodating station and an antenna site is shared by multiple cells, the required bandwidth of the entire transmission path changes depending on the combination of base station function layouts of each cell. For this reason, a cell group is formed from multiple cells that share the same transmission path.

In FIG. 9, three cells belonging to cell group A (group ID = GID1) share a transmission path 401 between the accommodating station and the antenna site. Also, four cells belonging to cell group B (group ID = GID2) share a transmission path 402 between the accommodating station and the antenna site. As a result, the three cells that share the same transmission path 401 are determined to be cell group A (group ID = GID1). On the other hand, the four cells that share the same transmission path 402 are determined to be cell group B (group ID = GID2).

According to example 1 of the cell group determination method, as illustrated in FIG. 10, the base station function arrangement is changed sequentially in multiple cells (Cell #1, Cell #2, Cell #3) belonging to the same cell group to avoid congestion based on the observed value of the overall bandwidth utilization rate of the transmission path shared by the multiple cells, thereby appropriately adjusting the bandwidth utilization rate and providing robustness against traffic fluctuations.

(Example 2 of cell group determination method)
11 is an explanatory diagram of a second example of the cell group determination method according to the present embodiment. In the second example of the cell group determination method, a cell group is composed of a plurality of cells that satisfy a predetermined radio wave influence criterion. For example, the radio wave influence criterion is that the cell interval is within a predetermined distance. The radio wave influence criterion may be that the influence of radio waves is equal to or greater than a predetermined criterion. For example, the radio wave influence criterion is that the received signal strength indicator (RSSI) is equal to or greater than a criterion value.

CoMP is a technology that can improve wireless communication quality at cell edges where radio interference is strong by transmitting radio waves from multiple antennas in a coordinated manner. Whether or not inter-cell cooperation can be used depends on the base station function arrangement. Specifically, inter-cell cooperation can be used with C-RAN arrangement, but inter-cell cooperation cannot be used with S-RAN arrangement and D-RAN arrangement. Therefore, even if a certain cell can use inter-cell cooperation, whether or not a terminal located at the cell edge of that cell can use inter-cell cooperation depends on the base station function arrangement of the cells surrounding that cell. For this reason, a single cell group is formed from multiple cells that satisfy a specified radio wave influence standard.

In FIG. 11, the four cells belonging to cell group C (group ID = GID3) have a cell spacing within a predetermined distance. Also, the four cells belonging to cell group D (group ID = GID4) have a cell spacing within a predetermined distance. This determines cell group C (group ID = GID3) and cell group D (group ID = GID4), each consisting of four cells.

According to Example 2 of the cell group determination method, a certain cell can change the base station function arrangement between cells so that inter-cell cooperation can be efficiently used, taking into account the movement of users (terminals) and the radio environment, based on whether or not inter-cell cooperation is available in surrounding cells. For example, in FIG. 12, since the surrounding cell (Cell #12) of the cell (Cell #11) is in a C-RAN arrangement, if the cell changes to a C-RAN arrangement, terminal UE2 can use inter-cell cooperation. On the other hand, since the surrounding cell (Cell #14) of the cell (Cell #11) is in an S-RAN arrangement, terminal UE1 cannot use inter-cell cooperation even if the cell changes to a C-RAN arrangement.

As described above, this embodiment has the advantage of being able to appropriately control the execution of base station function placement in an O-RAN-specification radio access network (RAN1).

According to this embodiment, for each cell group to which multiple cells included in RAN1 belong, the timing of changing the base station function layout for each cell belonging to the cell group is shifted. This makes it possible to reflect the result of changing the base station function layout of a cell in the same cell group in the change of the base station function layout of other cells.

According to this embodiment, when determining the placement of base station functions by distributed reinforcement learning, an "Actor" can observe changes in the network state due to the actions of other "Actors" and act accordingly. Meanwhile, at the timing of re-arrangement of each cell, only the cell at the timing of re-arrangement changes its base station function placement. Therefore, at the timing of re-arrangement of a certain cell, only the action of the "Actor" corresponding to that cell affects the network state, and the network can be controlled by the action of that "Actor" itself.

As a result, it will be possible to improve the overall service quality in wireless access networks, for example, and contribute to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote sustainable industrialization and foster innovation."

The above describes an embodiment of the present invention in detail with reference to the drawings, but the specific configuration is not limited to this embodiment and includes design modifications and the like that do not deviate from the gist of the present invention.

In addition, a computer program for implementing the functions of each of the above-mentioned devices may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Note that the term "computer system" may include hardware such as an OS and peripheral devices.
In addition, the term "computer-readable recording medium" refers to a storage device such as a flexible disk, a magneto-optical disk, a ROM, a writable non-volatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disc), or a hard disk built into a computer system.

Furthermore, the term "computer-readable recording medium" includes devices that retain a program for a certain period of time, such as volatile memory (e.g., DRAM (Dynamic Random Access Memory)) within a computer system that serves as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line.
The program may be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium, or by a transmission wave in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for implementing some of the functions described above, or may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already recorded in the computer system.

1...Radio access network (RAN), 2...Base station function group, 10...SMO framework, 11...SMO function unit, 12...Non-RT RIC, 20...Base station function placement control unit, 220...Cell group information storage unit, 203...KPI acquisition unit, 204...Base station function placement setting information transmission unit, 205...Control unit

Claims (8)

a cell group information storage unit configured to store cell group information indicating a cell group to which a plurality of cells included in a radio access network conforming to the O-RAN specification belong;
A control unit that shifts a timing of changing the base station function allocation for each cell belonging to one of the cell groups;
Equipped with
The cell group is composed of a plurality of cells sharing the same transmission path,
the transmission path is a transmission path between an accommodation station and an antenna site,
The required bandwidth of the transmission path varies depending on the base station function layout,
the control unit sequentially changes the base station function allocation in the plurality of cells so as to avoid congestion based on an observed value of an overall bandwidth utilization rate of a transmission path shared by the plurality of cells belonging to the same cell group.
Base station function arrangement control device. The cell group is composed of a plurality of cells that satisfy a predetermined radio wave influence criterion.
The base station function arrangement control device according to claim 1. The radio wave influence criterion is that the cell interval is within a predetermined distance.
The base station function arrangement control device according to claim 2 . The radio wave influence standard is that the influence of radio waves is equal to or greater than a predetermined standard.
The base station function arrangement control device according to claim 2 . The control unit determines a base station function allocation for each cell included in the radio access network by distributed reinforcement learning.
The base station function arrangement control device according to any one of claims 1 to 4 . The base station function arrangement control device is realized using a "Non-RT RIC (Non-Real Time RAN Intelligent Controller)".
The base station function arrangement control device according to any one of claims 1 to 5 . A base station function arrangement control method in an O-RAN radio access network, comprising:
a cell group information storage step in which the base station function arrangement control device stores cell group information indicating a cell group to which a plurality of cells included in the radio access network of the O-RAN specification belong;
a control step of the base station function arrangement control device shifting a timing of changing the arrangement of base station functions for each cell belonging to one of the cell groups;
Including,
The cell group is composed of a plurality of cells sharing the same transmission path,
the transmission path is a transmission path between an accommodation station and an antenna site,
The required bandwidth of the transmission path varies depending on the base station function layout,
the control step sequentially changes the base station function allocation in the plurality of cells so as to avoid congestion based on an observed value of an overall bandwidth utilization rate of a transmission path shared by the plurality of cells belonging to the same cell group;
A base station function arrangement control method. The computer of the base station function arrangement control device
A cell group information storage step of storing cell group information indicating a cell group to which a plurality of cells included in the radio access network of the O-RAN specification belong;
A control step of shifting the timing of changing the base station function allocation for each cell belonging to one of the cell groups;
Run the command ,
The cell group is composed of a plurality of cells sharing the same transmission path,
the transmission path is a transmission path between an accommodation station and an antenna site,
The required bandwidth of the transmission path varies depending on the base station function layout,
the control step sequentially changes the base station function allocation in the plurality of cells so as to avoid congestion based on an observed value of an overall bandwidth utilization rate of a transmission path shared by the plurality of cells belonging to the same cell group;
Computer program.

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