WO2024161628A1

WO2024161628A1 - Control device and switching control method

Info

Publication number: WO2024161628A1
Application number: PCT/JP2023/003571
Authority: WO
Inventors: 拓弥原田; 慈仁酒井; 達也島田
Original assignee: 日本電信電話株式会社
Priority date: 2023-02-03
Filing date: 2023-02-03
Publication date: 2024-08-08

Abstract

Provided is a control device comprising a control unit that uses a protocol for making a default gateway redundant in a server to be switched and a server to switch to, which implement a transfer function and a base station function in a wireless access network, by virtualization technology, to group the transfer function implemented in the server to be switched and the transfer function implemented in the server to switch to, and switch routes by stopping the transfer function implemented in the server to be switched or changing the value of a priority thereof for transition to a standby state.　

Description

Control device and switching control method

The present invention relates to a control device and a switching control method.

　Conventionally, vRAN (virtualized RAN) has been proposed, which virtualizes the RAN (virtualized Radio Access Network) network using virtualization technology. In vRAN, base station functions equivalent to parent stations in 5G (5th Generation) (for example, CU (Central Unit) and DU (Distributed Unit)) are virtualized within a general-purpose server, making it possible to process communications without using dedicated hardware.

In network control for flexible function deployment in vRAN, for example, when moving a CU in accordance with the movement of a MEC (Mobile Edge Computing), it is necessary to rewrite the information held by the opposing DU. On the other hand, in order to provide timely services in response to user requests, a method of switching without rewriting the information of the opposing node is required. For example, if a parameter that specifies a node on a network, such as an IP address, is set in the CU, moving the CU container to match the MEC and attempting to reconnect with the DU will cause an IP address inconsistency on the network. As a result, communication is not possible until the IP address or MAC address of the target CU disappears from the ARP (Address Resolution Protocol) table. As a result, there was a problem in that it was not easy to switch base station functions.

In light of the above circumstances, the present invention aims to provide technology that can easily switch base station functions in a wireless access network.

One aspect of the present invention is a control device that uses a protocol that uses virtualization technology to make default gateways redundant in a source server and a destination server that realize a forwarding function and a base station function in a wireless access network, and that groups the forwarding function realized in the source server and the forwarding function realized in the destination server, and switches the route by stopping the forwarding function realized in the source server or by changing the priority value and transitioning it to a standby state.

One aspect of the present invention is a switching control method that uses a protocol that uses virtualization technology to make default gateways redundant in a source server and a destination server that realize a forwarding function and a base station function in a wireless access network, groups the forwarding function realized in the source server and the forwarding function realized in the destination server, and switches the route by stopping the forwarding function realized in the source server or changing the priority value and transitioning it to a standby state.

The present invention makes it possible to easily switch base station functions in a wireless access network.

1 is a diagram illustrating an example of a configuration of a wireless access network system according to a first embodiment. 1 is a diagram for explaining an overview of a radio access network system in a first embodiment. FIG. FIG. 2 is a diagram illustrating a configuration example of a NW controller according to the first embodiment. FIG. 2 is a sequence diagram showing a processing flow of the wireless access network system in the first embodiment. 10 is a flowchart showing a flow of a communication confirmation process in the wireless access network system according to the first embodiment. FIG. 11 is a diagram illustrating an example of a configuration of a wireless access network system according to a second embodiment. FIG. 11 is a sequence diagram showing a processing flow of the radio access network system according to the second embodiment. FIG. 13 is a diagram illustrating an example of a configuration of a wireless access network system according to a third embodiment. FIG. 13 is a sequence diagram showing the flow of processing (part 1) of the wireless access network system in the third embodiment. FIG. 13 is a sequence diagram showing the flow of processing (part 2) of the wireless access network system in the third embodiment. FIG. 13 is a sequence diagram showing the flow of processing (part 2) of the wireless access network system in the third embodiment. FIG. 13 is a diagram illustrating an example of a configuration of a wireless access network system in a fourth embodiment. FIG. 13 is a diagram for explaining an overview of a radio access network system in a fourth embodiment. FIG. 13 is a sequence diagram showing a processing flow of the radio access network system in the fourth embodiment. FIG. 13 is a diagram illustrating an example of the configuration of a wireless access network system in a fifth embodiment. FIG. 13 is a sequence diagram showing the flow of processing (part 1) of the wireless access network system in the fifth embodiment. FIG. 13 is a sequence diagram showing the flow of processing (part 2) of the wireless access network system in the fifth embodiment. FIG. 13 is a sequence diagram showing the flow of processing (part 2) of the wireless access network system in the fifth embodiment. FIG. 23 is a sequence diagram showing a processing flow of the radio access network system in the sixth embodiment. FIG. 23 is a sequence diagram showing a processing flow of the wireless access network system in the seventh embodiment. A sequence diagram showing the flow of processing (part 1) of the wireless access network system in the eighth embodiment. A sequence diagram showing the flow of processing (part 2) of the wireless access network system in the eighth embodiment. A sequence diagram showing the flow of processing (part 2) of the wireless access network system in the eighth embodiment. FIG. 23 is a sequence diagram showing the processing flow of the radio access network system in the ninth embodiment. A sequence diagram showing the flow of processing (part 1) of the wireless access network system in the tenth embodiment. A sequence diagram showing the flow of processing (part 2) of the wireless access network system in the tenth embodiment. A sequence diagram showing the flow of processing (part 2) of the wireless access network system in the tenth embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First Embodiment
FIG. 1 is a diagram showing a configuration example of a radio access network system 100 in the first embodiment. The radio access network system 100 in the first embodiment is, for example, a fifth generation mobile communication system (hereinafter referred to as "5G"). The radio access network system 100 includes a radio station 10, a server 20, a plurality of servers 30-1 and 30-2, a 5GC 40, a NW controller 50, and a network 60. The number of radio stations 10, servers 20, and servers 30 included in the radio access network system 100 is not particularly limited. In the following description, when the servers 30-1 and 30-2 are not particularly distinguished from each other, they are simply referred to as server 30.

The wireless station 10 is, for example, a Radio Unit (RU) in the 5G communication standard. The wireless station 10 has one or more antennas and performs wireless communication with a terminal. For example, the wireless station 10 receives a wireless signal transmitted from the terminal, converts the received wireless signal into an electrical signal, and transmits it to the server 20.

Server 20 is a server that realizes base station functions using virtualization technology. Specifically, server 20 realizes the functions of a DU (Distributed Unit) in the 5G communication standard and the functions of a layer 2 router as a base station function using virtualization technology. As a result, server 20 virtually comprises a virtual DU 21 and a virtual router 22. Note that the virtualization of server 20 may use any of the following technologies: host OS (Operation System) type, hypervisor type, or container type.

The virtual DU 21 performs the same processing as the DU in the 5G communication standard. For example, the virtual DU 21 is a virtualized wireless signal processing unit that processes wireless signals received by the wireless station 10. The virtual router 22 is a virtualized forwarding device with a route control function. The virtual router 22 is a forwarding device that supports the Virtual Router Redundancy Protocol (VRRP).

Server 30 is a server that realizes base station functions using virtualization technology. Specifically, server 30 realizes the functions of a CU (Centralized Unit) in the 5G communication standard and the functions of a layer 2 router as a base station function using virtualization technology. As a result, server 30 virtually comprises a virtual CU 31 and a virtual router 32. Note that the virtualization of server 30 may use any of the following technologies: host OS type, hypervisor type, or container type.

Server 30-1 and server 30-2 are installed in different physical locations. In the following explanation, server 30-1 is the source server, and server 30-2 is the destination server installed in a new location.

The virtual CU 31 performs the same processing as a CU in the 5G communication standard. For example, the virtual CU 31 is a virtualized data processing unit that performs data processing. The virtual router 32 is a virtualized transfer device with a route control function. The virtual router 32 is a VRRP-compatible transfer device.

The 5GC40 is a core network device for 5G.

The NW controller 50 controls routers (e.g., virtual router 22 and virtual router 32) that perform route control in the wireless access network system 100. In the first embodiment, the NW controller 50 is described as controlling the virtual router 32 that is realized on the server 30. The NW controller 50 is one aspect of a control device.

Network 60 is an external network. Network 60 is, for example, the Internet.

The wireless station 10, server 20, servers 30-1, 30-2, and 5GC 40 are devices located within the same network. The optical transmission path connecting the wireless station 10, server 20, servers 30-1, 30-2, and 5GC 40 is configured by an APN (All Photonics Network).

Next, an overview of the wireless access network system 100 in the first embodiment will be described with reference to FIG. 2. FIG. 2 is a diagram for explaining an overview of the wireless access network system 100 in the first embodiment. In FIG. 2, the old edge site represents the location where the source server 30-1 is located, and the new edge site represents the location where the destination server 30-2 is located. First, assume that the servers 20 and 30-1 are communicating. In this case, a signal received by the virtual DU 21 of the server 20 is transferred by the virtual router 22 to the virtual router 32-1 of the server 30-1. The virtual CU 31-1 of the server 30 acquires the signal transferred from the virtual router 22 via the virtual CU 31-1.

In such a situation, it is considered that server 30 with CU function is moved to a location different from where server 30-1 is located due to a change in the network. In order to realize timely service deployment, it is necessary to reduce the work time and minimize communication disconnections. Therefore, in this embodiment, by using a protocol (e.g., VRRP) that makes the default gateway redundant, the NW controller 50 performs control so that there are no multiple nodes (e.g., server 30) that hold the same IP address on the APN.

Specifically, server 30-2 is newly installed in a location within the same network as server 30-1, but at a physical distance from the location where server 30-1 is located, and virtual CU 31-2 and virtual router 32-2 are started on server 30-2. Here, server 30-2 creates virtual CU 31-2 with the same contents as virtual CU 31-1, which is the source of switching. When the startup of virtual router 32-2 is complete, NW controller 50 sets VRRP for virtual router 32-1 and virtual router 32-2. For example, NW controller 50 sets the same VIP for virtual router 32-1 and virtual router 32-2 and groups them.

Between virtual router 32-1 and virtual router 32-2, the virtual router 32 with the highest priority is set as the master router by VRRP. In the following explanation, it is assumed that the priority of the original virtual router 32-1 is the highest. Therefore, the virtual router 32-1 is set as the master router, and the virtual router 32-2 is set as the backup router. After that, the NW controller 50 stops the original virtual router 32-1. As a result, the virtual router 32-2 detects that the virtual router 32-1 has gone down and sets itself as the master router. Note that the NW controller 50 may change the priority value of the original virtual router 32-1 (for example, the priority of virtual router 32-1 < the priority of virtual router 32-2) and move the virtual router 32-1 to a standby state. In this case, the virtual router 32-2 sets itself as the master router by comparing the priority with that of the virtual router 32-1.

The virtual router 32-2 notifies the virtual MAC address corresponding to the VIP using GARP (Gratuitous Address Resolution Protocol). The virtual router 22 updates the ARP table according to the notified virtual MAC address. As a result, communication becomes possible between the switching destination server 30-2 and server 20. This makes it possible to migrate to any location without changing the settings of the base station function (for example, virtual CU 31).

FIG. 3 is a diagram showing an example of the configuration of the NW controller 50 in the first embodiment. The NW controller 50 includes a communication unit 51 and a control unit 52. The communication unit 51 communicates with other devices. For example, the communication unit 51 communicates with the server 30. The control unit 52 controls the entire NW controller 50. The control unit 52 is configured using one or more processors such as a CPU (Central Processing Unit) and one or more memories. The control unit 52 realizes the functions of an instruction unit 521 and a communication control unit 522 by the one or more processors executing programs.

The instruction unit 521 issues various instructions to the

servers

20 and 30. The instructions issued by the instruction unit 521 include, for example, an instruction to start the

virtual routers

22 and 32, an instruction to check communication, an instruction to create a VPPR group, and an instruction to shut down the

virtual routers

22 and 32. The instruction to start the

virtual routers

22 and 32 is an instruction to the

servers

20 and 30 to start the

virtual routers

22 and 32. The instruction to check communication is an instruction to perform a communication check between the virtual routers. The instruction to create a VPPR group is an instruction to create a group by VPPR between the virtual routers. The instruction to create a VPPR group includes at least a VIP (Virtual IP) and a virtual MAC (Media Access Control) address. The VIP is an IP address used to group virtual routers installed on the same network (same segment).

The shutdown instruction for the

virtual routers

22, 32 is an instruction to change the state of the

virtual routers

22, 32. Here, changing the state of the

virtual routers

22, 32 means transitioning the

virtual routers

22, 32 from master routers to backup routers. For example, the shutdown instruction may include an instruction to stop the functions of the

virtual routers

22, 32, or an instruction to change the priority of the

virtual routers

22, 32. If the shutdown instruction includes an instruction to change the priority of the virtual routers, it includes information indicating a priority such that the priority of the source

virtual routers

22, 32 is lower than the priority of the destination

virtual routers

22, 32. For example, the shutdown instruction may include information to change the priority to "1".

If the shutdown instruction includes an instruction to stop the function of the

virtual router

22, 32, the

server

20, 30 that receives the shutdown instruction stops the function of the

virtual router

22, 32. If the shutdown instruction includes an instruction to change the priority of the virtual router, the

server

20, 30 that receives the shutdown instruction changes the priority of the

virtual router

22, 32. For example, the

server

20, 30 changes the priority of the

virtual router

22, 32 to the specified priority.

If communication cannot be confirmed between the source server 30-1 and the destination server 30-2, the communication control unit 522 performs various controls to enable communication between the source server 30-1 and the destination server 30-2. For example, the communication control unit 522 calculates the route between the virtual router 32-1 of the source server 30-1 and the virtual router 32-2 of the destination server 30-2, ensures communication in the physical layer (for example, ensures wavelengths in the APN), or ensures communication in the logical network (for example, changes the settings of a switch or router).

FIG. 4 is a sequence diagram showing the flow of processing in the wireless access network system 100 in the first embodiment. Note that in the processing in FIG. 4, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 32.

Server 20 and server 30-1 are in communication (step S101). Assume that server 30-2 is installed in a location physically separated from server 30-1. Server 30-2 creates a virtual CU 31-2 with the same contents as virtual CU 31-1 of server 30-1 (step S102). In response to a user operation, instruction unit 521 of NW controller 50 sends a virtual router startup instruction to server 30-2 via communication unit 51 to cause server 30-2 to start virtual router 32-2 (step S103).

The server 30-2 receives the start-up instruction sent from the NW controller 50. In response to the received start-up instruction, the server 30-2 starts the virtual router 32-2 using virtualization technology. When the start-up of the virtual router 32-2 is completed, the server 30-2 sends a start-up completion report to the NW controller 50 (step S104). The communication unit 51 of the NW controller 50 receives the completion report sent from the server 30-2. When the completion report is received, the instruction unit 521 sends a communication check instruction for the server 30-2 to the server 30-1 via the communication unit 51 (step S105). As a result, the server 30-1 performs a communication check process for the server 30-2 (step S106). The communication check process will be described later.

The server 30-1 transmits a communication check completion report to the NW controller 50 indicating that the communication check has been completed (step S107). Here, the server 30-1 transmits a communication check completion report to the NW controller 50 including a communication check result indicating that communication check has been completed for server 30-2. The communication unit 51 of the NW controller 50 receives the communication check completion report transmitted from the server 30-1. The instruction unit 521 of the NW controller 50 refers to the communication check result contained in the communication check completion report. As the communication check result indicates that communication check has been completed for server 30-2, the instruction unit 521 of the NW controller 50 transmits an instruction to create a VRRP group to the servers 30-1 and 30-2 via the communication unit 51 (step S108).

The servers 30-1 and 30-2 receive the VRRP group creation instruction sent from the NW controller 50. The servers 30-1 and 30-2 create a VRRP group in response to the received VRRP group creation instruction. The virtual router 32-1 of the server 30-1 and the virtual router 32-2 of the server 30-2 compare their priorities to set the master router and the backup router. Here, it is assumed that the virtual router 32-1 is set as the master router and the virtual router 32-2 is set as the backup router (steps S109 and S110). The servers 30-1 and 30-2 send a VRRP group completion report to the NW controller 50 indicating that the creation of the VRRP group has been completed (step S111). The communication unit 51 of the NW controller 50 receives the VRRP group completion reports sent from the servers 30-1 and 30-2, respectively.

After receiving the VRRP group completion reports from each of servers 30-1 and 30-2, the instruction unit 521 of the NW controller 50 transmits an instruction to shut down the virtual router 32-1 to the switching source server 30-1 via the communication unit 51 (step S112). At this time, the instruction unit 521 transmits a shut-down instruction including either an instruction to stop the function of the virtual router 32-1 or an instruction to change the priority of the virtual router 32-1 to the switching source server 30-1 via the communication unit 51 according to a predetermined setting. Here, it is assumed that the instruction unit 521 transmits a shut-down instruction including an instruction to stop the function of the virtual router 32-1 to the switching source server 30-1 via the communication unit 51.

The server 30-1 receives the shutdown instruction sent from the NW controller 50. The server 30-1 changes the state of the virtual router 32-1 according to the instruction contained in the shutdown instruction. For example, if the shutdown instruction contains an instruction to stop the function of the virtual router 32-1, the server 30-1 stops the function of the virtual router 32-1. As a result, the advertisement signal is no longer sent from the virtual router 32-1 to the virtual router 32-2. The advertisement signal is a signal that indicates that the master router is in a state where communication is possible.

When the virtual router 32-2 of the server 30-2 fails to receive an advertisement signal from the virtual router 32-1 for a certain period of time, it detects that the master router, virtual router 32-1, has gone down (step S113). After that, the virtual router 32-1 sets itself as the master router (step S114). After setting the master router, the virtual router 32-1 notifies the virtual MAC address corresponding to the VIP by GARP (step S115).

The wireless station 10 receives the virtual MAC address notified from the virtual router 32-1. The wireless station 10 updates the ARP table in accordance with the received virtual MAC address (step S116). For example, the wireless station 10 updates the ARP table by changing the output port addressed to the virtual MAC address to the port through which the virtual MAC address was received. After updating the ARP table, the wireless station 10 notifies the server 30-2 that communication is now possible (step S117).

Note that in the process of step S112, if the instruction unit 521 sends a cut-off instruction including an instruction to change the priority of the virtual router 32-1 to the switching source server 30-1 via the communication unit 51, the server 30-1 changes the priority of the virtual router 32-1. The cut-off instruction includes information indicating a priority (for example, priority "1") such that the priority of the switching source virtual router 32 (here, virtual router 32-1) is lower than the priority of the switching destination virtual router 32 (here, virtual router 32-2). Therefore, the server 30-1 sets the priority of the virtual router 32-1 to "1".

As a result, the priority of virtual router 32-1 becomes lower than the priority of virtual router 32-2. In this case, in step S113, virtual router 32-1 and virtual router 32-2 compare their priorities. As a result of the priority comparison, the priority of virtual router 32-2 is higher than the priority of virtual router 32-1, so virtual router 32-2 sets itself as the master router (step S114), and virtual router 32-1 sets itself as the backup router. As a result, virtual router 32-1 goes into a standby state. In this way, the NW controller 50 can change the priority of virtual router 32-1 of the switching source server 30-1 to make it the backup router, making it possible to switch routes without stopping the server.

FIG. 5 is a flowchart showing a flow of a communication confirmation process of the radio access network system 100 in the first embodiment.
The server 30-1 receives the communication check instruction sent from the NW controller 50 (step S201). In response to the communication check instruction, the virtual router 32-1 of the server 30-1 performs a communication check with the virtual router 32-2 of the server 30-2 (step S202). The virtual router 32-1 determines whether or not the communication check with the virtual router 32-2 has been successful (step S203).

If the virtual router 32-1 determines that the communication with the virtual router 32-2 has been confirmed (step S203-OK), the communication confirmation process ends. On the other hand, if the virtual router 32-1 determines that the communication with the virtual router 32-2 has not been confirmed (step S203-NG), it notifies the NW controller 50 that the communication with the virtual router 32-2 has not been confirmed. Communication with the virtual router 32-2 has not been confirmed when no response is obtained from the virtual router 32-2 in response to the signal sent from the virtual router 32-1.

The communication unit 51 of the NW controller 50 receives the notification sent from the virtual router 32-1. The communication control unit 522 calculates the route between the virtual routers 32-1 and 32-2 (step S204). Next, the communication control unit 522 ensures physical layer communication between the servers 30-1 and 30-2 (step S205). Then, the communication control unit 522 ensures logical network communication between the servers 30-1 and 30-2 (step S206).

After the processes from step S204 to step S206 have been executed, the instruction unit 521 again sends an instruction to server 30-1 to check communication (step S207). This causes the process of step S202 to be executed again. In this way, the NW controller 50 is controlled so that communication between the switching source server 30 and the switching destination server 30 is cut off upon confirmation.

In the radio access network system 100 configured as described above, the NW controller 50 uses VPPR in the source server 30-1 and the destination server 30-2 that realize the virtual CU 31 and the virtual router 32 by using virtualization technology, and groups the virtual router 32-1 realized in the source server 30-1 and the virtual router 32-2 realized in the destination server 30-2, and has a control unit 52 that switches the route by stopping the virtual router 32-1 realized in the source server 30-1 or changing the priority and putting it in a standby state. This makes it possible to easily realize network control for flexible function deployment in vRAN by using VRRP, which is an existing technology. And it becomes possible to perform network control such as CU switching in a short time. Therefore, it becomes possible to easily switch base station functions in the radio access network.

Second Embodiment
In the second embodiment, a configuration for performing network control in accordance with the movement of an MEC will be described.

FIG. 6 is a diagram showing an example of the configuration of a radio access network system 100a in the second embodiment. The radio access network system 100a includes a radio station 10, a server 20, a plurality of servers 30-1, 30-2, a 5GC 40, a NW controller 50, a network 60, an MEC 65, and an MEC controller 67. The radio access network system 100a differs in configuration from the radio access network system 100 in that it further includes an MEC 65 and an MEC controller 67. Other basic operations are the same as those of the radio access network system 100. The following description will focus on the differences from the radio access network system 100.

MEC65 is a device that constitutes edge computing. MEC65 is composed of, for example, part of 5GC40 (e.g., UPF (User Plane Function)/SMF (Session Management Function)) and a general-purpose server.

The MEC controller 67 is a device that controls the operation of the MEC 65.

FIG. 7 is a sequence diagram showing the flow of processing in the wireless access network system 100a in the second embodiment. In FIG. 7, the same processes as those in FIG. 4 are denoted by the same reference numerals as in FIG. 4, and the description thereof will be omitted. Note that in the processing in FIG. 7, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 32.

Assume that MEC 65 has been moved to an edge site before network 60 in order to reduce latency by shortening the transmission distance. MEC controller 67 starts up MEC 65 (step S301). Then, it executes the processes from step S101 onwards.

In addition, in the process of step S112, the instruction unit 521 may send a blocking instruction, including an instruction to change the priority of the virtual router 32-1, to the server 30-1, which is the switching source, via the communication unit 51. The specific process flow in this case has already been explained above, so it will not be explained here.

In the radio access network system 100a configured as described above, when the MEC 65 moves, the virtual CU 31-2 that communicates with the moved MEC 65 is started, and network control is performed using VRRP to prevent duplication of IP addresses within the same network. In this way, network control for flexible function deployment in a virtual radio access network can be easily achieved by using the existing technology VRRP. As a result, network control such as switching of base station functions (e.g., CU) can be performed in a short time.

Third Embodiment
In the third embodiment, a configuration will be described in which the OS of a virtual CU is updated in addition to switching the path.

FIG. 8 is a diagram showing an example of the configuration of a radio access network system 100b in the third embodiment. The radio access network system 100b includes a radio station 10, a plurality of servers 20, a plurality of servers 30-1, 30-2, a 5GC 40, a NW controller 50, a network 60, and a base station controller 70. The radio access network system 100b differs in configuration from the radio access network system 100 in that it further includes a base station controller 70. Note that the number of radio stations 10, servers 20, and servers 30 included in the radio access network system 100b is not particularly limited. Other basic operations are the same as those of the radio access network system 100. The following description will focus on the differences from the radio access network system 100.

In the third embodiment, the communication unit 51 of the NW controller 50 communicates with the server 30 and with the base station controller 70.

The base station controller 70 manages and controls the CU (e.g., virtual CU 31) or DU (e.g., virtual DU 21) functions, and issues instructions such as updating the OS of the CU or DU. In the third embodiment, the base station controller 70 manages and controls the virtual CU 31-1 and CU 31-2 functions.

FIG. 9 is a sequence diagram showing the flow of processing (part 1) of the wireless access network system 100b in the third embodiment. Note that FIG. 9 describes a pattern in which the OS update destination is not switched back. In FIG. 9, the same processes as in FIG. 4 are denoted with the same reference numerals as in FIG. 4 and the description is omitted. Note that in the processing in FIG. 9, the shutdown instruction is described as including an instruction to stop the function of the virtual router 32.

The base station controller 70 sends an OS update instruction to the server 30-2 to have the switching destination server 30-2 start up with the updated OS (step S401). The server 30-2 receives the OS update instruction sent from the base station controller 70. In response to receiving the OS update instruction, the server 30-2 starts up the virtual CU 31-2 with the new OS of the virtual CU 31-1 of the server 30-1 (step S402). The base station controller 70 instructs the NW controller 50 to start up the virtual router under the virtual CU 31-2 that is the target of the OS update (step S403).

In response to an instruction from the base station controller 70, the NW controller 50 transmits a virtual router startup instruction to the server 30-2 via the communication unit 51 to cause the server 30-2 to start the virtual router 32-2 (step S404). Then, the processes from step S104 to step S111 are executed. After the process of step S111, the communication unit 51 of the NW controller 50 transmits an OS update preparation completion report to the base station controller 70 indicating that preparation for the OS update has been completed (step S405).

The base station controller 70 receives the OS update preparation completion report sent from the NW controller 50. In response to the received OS update preparation completion report, the base station controller 70 sends a switching instruction from virtual CU 31-1 to virtual CU 31-2 to the NW controller 50 (step S406). The communication unit 51 of the NW controller 50 receives the switching instruction sent from the base station controller 70. After receiving the switching instruction, the instruction unit 521 sends an instruction to shut down the virtual router 32-1 to the server 30-1, which is the switching source, via the communication unit 51 (step S407). Then, the processing from step S113 onwards is executed.

In addition, in the process of step S407, the instruction unit 521 may send a blocking instruction, including an instruction to change the priority of the virtual router 32-1, to the server 30-1, which is the switching source, via the communication unit 51. The specific process flow in this case has already been explained above, so it will not be explained here.

FIGS. 10 and 11 are sequence diagrams showing the flow of processing (part 2) of the wireless access network system 100b in the third embodiment. Note that in FIG. 10 and FIG. 11, a pattern of switching back the OS update destination is explained. In FIG. 10 and FIG. 11, the same processes as in FIG. 4 are assigned the same reference numerals as in FIG. 4, and explanations are omitted. Note that in the processing in FIG. 10 and FIG. 11, the shutdown instruction is explained as including an instruction to stop the function of the virtual router 32.

The base station controller 70 sends an OS update instruction to the server 30-2 (step S501). The server 30-2 receives the OS update instruction sent from the base station controller 70. In response to receiving the OS update instruction, the server 30-2 creates a virtual CU 31-2 with the same contents as the virtual CU 31-1 of the server 30-1 (step S502). The base station controller 70 instructs the NW controller 50 to start up the virtual router under the virtual CU 31-2 that is the target of the OS update (step S503).

In response to the instruction from the base station controller 70, the instruction unit 521 of the NW controller 50 sends a virtual router startup instruction to the server 30-2 via the communication unit 51 to cause the server 30-2 to start the virtual router 32-2 (step S504). Then, the processes from step S104 to step S111 are executed. After the process of step S111, the communication unit 51 of the NW controller 50 sends a backup destination preparation completion report to the base station controller 70 indicating that the backup destination preparation has been completed (step S505).

The base station controller 70 receives the backup destination preparation completion report sent from the NW controller 50. In response to the received backup destination preparation completion report, the base station controller 70 sends a switching instruction from virtual CU 31-1 to virtual CU 31-2 to the NW controller 50 (step S506). The communication unit 51 of the NW controller 50 receives the switching instruction sent from the base station controller 70. After receiving the switching instruction sent from the base station controller 70, the instruction unit 521 sends an instruction to shut down the virtual router 32-1 to the server 30-1, which is the switching source, via the communication unit 51 (step S507). Then, the processes from step S113 to step S117 are executed.

When processing with the wireless station 10 becomes possible, the server 30-2 transmits a switching completion report to the NW controller 50 indicating that switching has caused interference (step S508). The communication unit 51 of the NW controller 50 receives the switching completion report transmitted from the server 30-2. Upon receiving the switching completion report, the communication unit 51 of the NW controller 50 transmits an OS update preparation completion report to the base station controller 70 indicating that preparation for the OS update has been completed (step S509).

In response to receiving the OS update preparation completion report, the base station controller 70 updates the OS of the server 30-1 (step S510). This updates the OS of the server 30-1. When the OS update is complete, the server 30-1 transmits an OS update completion report to the base station controller 70 indicating that the update has been completed (step S511). The base station controller 70 receives the OS update completion report transmitted from the server 30-1. In response to receiving the OS update completion report, the base station controller 70 transmits a switchback instruction to the NW controller 50 (step S512).

The communication unit 51 of the NW controller 50 receives the switchback instruction sent from the base station controller 70. In response to the instruction from the base station controller 70, the instruction unit 521 of the NW controller 50 sends a virtual router startup instruction to the server 30-1 via the communication unit 51 to cause the server 30-1 to start the virtual router 32-1 (step S513).

In response to the startup instruction sent from the NW controller 50, the server 30-1 starts up the virtual router 32-1 (step S514). When the startup of the virtual router 32-1 is complete, the virtual router 32-1 of the server 30-1 and the virtual router 32-2 of the server 30-2 compare their priorities (step S515).

As a result of the priority comparison, the priority of virtual router 32-1 is higher than that of virtual router 32-2, so virtual router 32-1 sets itself as the master router, and virtual router 32-2 sets itself as the backup router (steps S516, S517). Server 30-1 notifies NW controller 50 that startup of virtual router 32-1 is complete (step S518). Communication unit 51 of NW controller 50 receives the notification from server 30-1. In response to the received notification, communication unit 51 of NW controller 50 transmits a switchover completion report to base station controller 70 indicating that switchover has been completed (step S519).

In addition, in the process of step S507, the instruction unit 521 may send a blocking instruction, including an instruction to change the priority of the virtual router 32-1, to the server 30-1, which is the switching source, via the communication unit 51. The specific process flow in this case has already been explained above, so it will not be explained here.

Note that in the process of step S507, if the instruction unit 521 transmits a cutoff instruction including an instruction to change the priority of the virtual router 32-1 to the server 30-1, which is the source of switching, via the communication unit 51, the priority of the virtual router 32-1 is lower than the priority of another virtual router 32 (for example, virtual router 32-2). Therefore, in the process of step S507, if the instruction unit 521 transmits a cutoff instruction including an instruction to change the priority of the virtual router 32-1 to the server 30-1, which is the source of switching, via the communication unit 51, and switching back is performed, the instruction unit 521 may include information on the new priority to be set in the start instruction for the virtual router in the process of step S513. For example, the instruction unit 521 may include information indicating a priority (for example, priority "255") such that the priority of the destination virtual router 32 (here, virtual router 32-1) is higher than the priority of the source virtual router 32 (here, virtual router 32-2) in the start instruction. As a result, when the switching destination virtual router 32-1 is started, the priority of the virtual router 32-1 becomes higher than the priority of the other virtual routers 32. This makes it possible to switch back.

The wireless access network system 100b configured as described above can achieve the same effects as the first embodiment.

Furthermore, in the wireless access network system 100b, the OS of the virtual CU 31 can also be updated. This makes it possible to process with the latest version even after switching.

Fourth Embodiment
In the first to third embodiments, a configuration for switching CUs in a section from DU to CU has been described. In the fourth embodiment, a configuration for switching DUs in a section from RU to DU will be described.

FIG. 12 is a diagram showing an example of the configuration of a wireless access network system 100c in the fourth embodiment. The wireless access network system 100c includes a wireless station 10, multiple servers 20-1 and 20-2, a server 30, a 5GC 40, a NW controller 50, and a network 60. Note that the number of wireless stations 10, servers 20, and servers 30 included in the wireless access network system 100c is not particularly limited. In the following description, when there is no particular distinction between the servers 20-1 and 20-2, they will simply be referred to as server 20.

In the wireless access network system 100c, the servers 20-1 and 20-2 are located in different physical locations. In the following explanation, it is assumed that the server 20-1 is the source server and the server 20-2 is the destination server installed in a new location. In this way, the configuration of the wireless access network system 100c when moving a virtual DU will be explained.

In the fourth embodiment, the communication unit 51 of the NW controller 50 communicates with the server 20.

The NW controller 50 in the fourth embodiment controls a router (e.g., virtual router 22 or virtual router 32) that performs route control in the wireless access network system 100c. In the fourth embodiment, the NW controller 50 is described as controlling the virtual router 22 realized on the server 20.

Next, an overview of the wireless access network system 100c in the fourth embodiment will be described with reference to FIG. 13. FIG. 13 is a diagram for explaining an overview of the wireless access network system 100c in the fourth embodiment. In FIG. 13, the old edge site represents the location where the switch-source server 20-1 is located, and the new edge site represents the location where the switch-destination server 20-2 is located. First, it is assumed that the wireless station 10 and the server 20-1 are communicating. In this case, a signal received by the wireless station 10 is forwarded to the server 20-1. The virtual DU 21-1 of the server 20 acquires the signal forwarded from the wireless station 10.

In such a situation, it is considered that server 20 with DU function is moved to a location different from where server 20-1 is located due to a change in the network. In order to realize timely service deployment, it is necessary to reduce the work time and minimize communication disconnections. Therefore, in this embodiment, by using a protocol (e.g., VRRP) that makes the default gateway redundant, the NW controller 50 controls so that there are no multiple nodes (e.g., server 20) that hold the same IP address on the APN.

Specifically, server 20-2 is newly installed in a location within the same network as server 20-1, but at a physical distance from the location where server 20-1 is located, and virtual DU 21-2 and virtual router 22-2 are started on server 20-2. Here, server 20-2 creates virtual DU 21-2 with the same contents as virtual DU 21-1, which is the source of switching. When the startup of virtual router 22-2 is complete, NW controller 50 sets VRRP for virtual router 22-1 and virtual router 22-2. For example, NW controller 50 sets the same VIP for virtual router 22-1 and virtual router 22-2 and groups them.

Between virtual router 22-1 and virtual router 22-2, the virtual router 22 with the highest priority is set as the master router by VRRP. In the following explanation, it is assumed that the priority of the original virtual router 22-1 is the highest. Therefore, the virtual router 22-1 is set as the master router, and the virtual router 22-2 is set as the backup router. After that, the NW controller 50 stops the original virtual router 22-1. As a result, the virtual router 22-2 detects that the virtual router 22-1 has gone down and sets itself as the master router. Note that the NW controller 50 may change the priority value of the original virtual router 22-1 (for example, the priority of virtual router 22-1 < the priority of virtual router 22-2) and move the virtual router 22-1 to a standby state. In this case, the virtual router 22-2 sets itself as the master router by comparing the priority with that of the virtual router 22-1.

The virtual router 22-2 notifies the virtual MAC address corresponding to the VIP by GARP. The virtual router 22 updates the ARP table according to the notified virtual MAC address. As a result, communication becomes possible between the switching destination server 20-2 and the wireless station 10. This makes it possible to migrate to any location without changing the settings of the base station function (for example, the virtual DU 21).

FIG. 14 is a sequence diagram showing the flow of processing in the wireless access network system 100c in the fourth embodiment. Note that in the processing in FIG. 14, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 22.

Server 20 and server 20-1 are in communication (step S601). Assume that server 20-2 is installed in a location physically separated from server 20-1. Server 20-2 creates virtual DU 21-2 with the same contents as virtual DU 21-1 of server 20-1 (step S602). In response to a user operation, instruction unit 521 of NW controller 50 sends a virtual router startup instruction to server 20-2 via communication unit 51 to cause server 20-2 to start virtual router 22-2 (step S603).

The server 20-2 receives the start instruction sent from the NW controller 50. In response to the received start instruction, the server 20-2 starts the virtual router 22-2 using virtualization technology. When the start of the virtual router 22-2 is completed, the server 20-2 sends a start completion report to the NW controller 50 (step S604). The communication unit 51 of the NW controller 50 receives the completion report sent from the server 20-2. When the completion report is received, the instruction unit 521 sends a communication check instruction for the server 20-2 to the server 20-1 via the communication unit 51 (step S605). As a result, the server 20-1 performs a communication check process for the server 20-2 (step S606). The communication check process in FIG. 14 can be performed by replacing the server 30 shown in FIG. 5 with the server 20 and the virtual router 32 with the virtual router 22.

The server 20-1 transmits a communication check completion report to the NW controller 50 indicating that the communication check has been completed (step S607). Here, the server 20-1 transmits a communication check completion report to the NW controller 50 including a communication check result indicating that communication check of the server 20-2 has been completed. The communication unit 51 of the NW controller 50 receives the communication check completion report transmitted from the server 20-1. The instruction unit 521 of the NW controller 50 refers to the communication check result contained in the communication check completion report. Since the communication check result indicates that communication check of the server 20-2 has been completed, the instruction unit 521 of the NW controller 50 transmits an instruction to create a VRRP group to the servers 20-1 and 20-2 via the communication unit 51 (step S608).

The servers 20-1 and 20-2 receive the VRRP group creation instruction sent from the NW controller 50. The servers 20-1 and 20-2 create a VRRP group in response to the received VRRP group creation instruction. The virtual router 22-1 of the server 20-1 and the virtual router 22-2 of the server 20-2 compare their priorities to set the master router and the backup router. Here, it is assumed that the virtual router 22-1 is set as the master router and the virtual router 22-2 is set as the backup router (steps S609 and S610). The servers 20-1 and 20-2 send a VRRP group completion report to the NW controller 50 indicating that the creation of the VRRP group has been completed (step S611). The communication unit 51 of the NW controller 50 receives the VRRP group completion reports sent from the servers 20-1 and 20-2, respectively.

After receiving the VRRP group completion reports from each of the servers 20-1 and 20-2, the instruction unit 521 of the NW controller 50 transmits an instruction to shut down the virtual router 22-1 to the server 20-1, which is the switching source, via the communication unit 51 (step S612). The server 30-1 stops the virtual router 22-1 in response to the shutdown instruction transmitted from the NW controller 50. As a result, the advertisement signal is no longer transmitted from the virtual router 22-1 to the virtual router 22-2.

When the virtual router 22-2 of the server 20-2 fails to receive an advertisement signal from the virtual router 22-1 for a certain period of time, it detects that the virtual router 22-1, which is the master router, has gone down (step S613). After that, the virtual router 22-1 sets itself as the master router (step S614). After setting the master router, the virtual router 22-1 notifies the virtual MAC address corresponding to the VIP by GARP (step S615).

The wireless station 10 receives the virtual MAC address notified by the virtual router 22-1. The wireless station 10 updates the ARP table according to the received virtual MAC address (step S616). For example, the wireless station 10 updates the ARP table by changing the output port addressed to the virtual MAC address to the port through which the virtual MAC address was received. After updating the ARP table, the wireless station 10 notifies the server 20-2 that communication is now possible (step S617).

Note that in the process of step S612, when the instruction unit 521 transmits a cutoff instruction including an instruction to change the priority of the virtual router 22-1 to the switching source server 20-1 via the communication unit 51, the server 20-1 changes the priority of the virtual router 22-1. The cutoff instruction includes information indicating a priority (for example, priority "1") such that the priority of the switching source virtual router 22 (here, virtual router 22-1) is lower than the priority of the switching destination virtual router 22 (here, virtual router 22-2). Therefore, the server 20-1 sets the priority of the virtual router 22-1 to "1".

As a result, the priority of virtual router 22-1 becomes lower than the priority of virtual router 22-2. In this case, in step S613, virtual router 22-1 and virtual router 22-2 compare their priorities. As a result of the priority comparison, the priority of virtual router 22-2 is higher than the priority of virtual router 22-1, so virtual router 22-2 sets itself as the master router (step S614), and virtual router 22-1 sets itself as the backup router. As a result, virtual router 22-1 goes into a standby state. In this way, the NW controller 50 can change the priority of virtual router 22-1 of the switching source server 20-1 to make it the backup router, making it possible to switch routes without stopping the server.

In the radio access network system 100c configured as described above, the NW controller 50 uses VPPR in the source server 20-1 and the destination server 20-2 that realize the virtual DU 21 and the virtual router 22 by using virtualization technology, and groups the virtual router 22-1 realized in the source server 20-1 and the virtual router 22-2 realized in the destination server 20-2, and has a control unit 52 that switches the route by stopping the virtual router 22-1 realized in the source server 20-1 or changing the priority and putting it in a standby state. This makes it possible to easily realize network control for flexible function deployment in vRAN by using VRRP, which is an existing technology. It is also possible to perform network control such as DU switching in a short time. This makes it possible to easily switch base station functions in the radio access network.

Fifth Embodiment
In the fifth embodiment, a configuration will be described in which the OS of a virtual DU is updated in addition to switching the path.

FIG. 15 is a diagram showing an example of the configuration of a radio access network system 100d in the fifth embodiment. The radio access network system 100b includes a radio station 10, a plurality of servers 20, a plurality of servers 30-1, 30-2, a 5GC 40, a NW controller 50, a network 60, and a base station controller 70. The number of radio stations 10, servers 20, and servers 30 included in the radio access network system 100d is not particularly limited. The radio access network system 100d differs in configuration from the radio access network system 100c in that it further includes a base station controller 70. Other basic operations are similar to those of the radio access network system 100c. The following mainly describes the differences from the radio access network system 100c.

In the fifth embodiment, the communication unit 51 of the NW controller 50 communicates with the server 20 and between the server 20 and itself.

The NW controller 50 in the fifth embodiment controls a router (e.g., virtual router 22 or virtual router 32) that performs route control in the wireless access network system 100d. In the fifth embodiment, the NW controller 50 is described as controlling the virtual router 22 realized on the server 20.

The base station controller 70 manages and controls the CU (e.g., virtual CU 31) or DU (e.g., virtual DU 21) functions, and issues instructions such as updating the OS of the CU or DU. In the fifth embodiment, the base station controller 70 manages and controls the virtual DU 21-1 and DU 21-2 functions.

FIG. 16 is a sequence diagram showing the flow of processing (part 1) of the wireless access network system 100d in the fifth embodiment. Note that FIG. 16 describes a pattern in which the OS update destination is not switched back. In FIG. 16, the same processes as in FIG. 14 are denoted with the same reference numerals as in FIG. 14 and the description is omitted. Note that in the processing in FIG. 16, the shutdown instruction is described as including an instruction to stop the function of the virtual router 22.

The base station controller 70 sends an OS update instruction to the server 20-2 to have the switching destination server 20-2 start up with the updated OS (step S701). The server 20-2 receives the OS update instruction sent from the base station controller 70. In response to receiving the OS update instruction, the server 20-2 starts up the virtual DU 21-2 with the new OS of the virtual DU 21-1 of the server 20-1 (step S702). The base station controller 70 instructs the NW controller 50 to start up the virtual router under the virtual DU 21-2 that is the target of the OS update (step S703).

In response to the instruction from the base station controller 70, the NW controller 50 instructs the server 20-2 to start up a virtual router (step S704). Then, the processes from step S604 to step S611 are executed. After the process of step S111, the NW controller 50 transmits an OS update preparation completion report to the base station controller 70 indicating that preparation for the OS update has been completed (step S705).

The base station controller 70 receives the OS update preparation completion report sent from the NW controller 50. In response to the received OS update preparation completion report, the base station controller 70 sends a switching instruction from virtual DU 21-1 to virtual DU 21-2 to the NW controller 50 (step S706). The communication unit 51 of the NW controller 50 receives the switching instruction sent from the base station controller 70. After receiving the switching instruction, the instruction unit 521 sends an instruction to shut down the virtual router 22-1 to the server 20-1, which is the switching source, via the communication unit 51 (step S707). Then, the processing from step S613 onwards is executed.

In addition, in the process of step S707, the instruction unit 521 may send a blocking instruction, including an instruction to change the priority of the virtual router 22-1, to the server 20-1, which is the switching source, via the communication unit 51. The specific process flow in this case has already been described above, so it will not be described here.

FIGS. 17 and 18 are sequence diagrams showing the flow of processing (part 2) of the wireless access network system 100d in the fifth embodiment. Note that in FIG. 17 and FIG. 18, a pattern of switching back the OS update destination is explained. In FIG. 17 and FIG. 18, the same processes as in FIG. 14 are assigned the same reference numerals as in FIG. 14, and explanations are omitted. Note that in the processing in FIG. 17 and FIG. 18, the shutdown instruction is explained as including an instruction to stop the function of the virtual router 22.

The base station controller 70 sends an OS update instruction to the server 20-2 (step S801). The server 20-2 receives the OS update instruction sent from the base station controller 70. In response to receiving the OS update instruction, the server 20-2 creates a virtual DU 21-2 with the same contents as the virtual DU 21-1 of the server 20-1 (step S802). The base station controller 70 instructs the NW controller 50 to start up the virtual router under the virtual DU 21-2 that is the target of the OS update (step S803).

In response to the instruction from the base station controller 70, the instruction unit 521 of the NW controller 50 sends a virtual router startup instruction to the server 20-2 via the communication unit 51 to cause the server 20-2 to start the virtual router 22-2 (step S804). Then, the processes from step S604 to step S611 are executed. After the process of step S111, the communication unit 51 of the NW controller 50 sends a backup destination preparation completion report to the base station controller 70 indicating that the backup destination preparation has been completed (step S805).

The base station controller 70 receives the backup destination preparation completion report sent from the NW controller 50. In response to the received backup destination preparation completion report, the base station controller 70 sends a switching instruction from virtual DU 21-1 to virtual DU 21-2 to the NW controller 50 (step S806). The communication unit 51 of the NW controller 50 receives the switching instruction sent from the base station controller 70. After receiving the switching instruction sent from the base station controller 70, the instruction unit 521 sends an instruction to shut down the virtual router 22-1 to the server 20-1, which is the switching source, via the communication unit 51 (step S807). Then, the processes from step S613 to step S617 are executed.

When processing with the wireless station 10 becomes possible, the server 20-2 transmits a switching completion report to the NW controller 50 indicating that switching has caused interference (step S808). The communication unit 51 of the NW controller 50 receives the switching completion report transmitted from the server 20-2. Upon receiving the switching completion report, the communication unit 51 of the NW controller 50 transmits an OS update preparation completion report to the base station controller 70 indicating that preparation for the OS update has been completed (step S809).

In response to receiving the OS update preparation completion report, the base station controller 70 updates the OS of the server 20-1 (step S810). This updates the OS of the server 20-1. When the OS update is complete, the server 20-1 transmits an OS update completion report indicating the completion of the update to the base station controller 70 (step S811). The base station controller 70 receives the OS update completion report transmitted from the server 20-1. In response to receiving the OS update completion report, the base station controller 70 transmits a switchback instruction to the NW controller 50 (step S812).

The communication unit 51 of the NW controller 50 receives the switchback instruction sent from the base station controller 70. In response to the instruction from the base station controller 70, the instruction unit 521 of the NW controller 50 sends a virtual router startup instruction to the server 20-1 via the communication unit 51 to cause the server 20-1 to start the virtual router 22-1 (step S813). In response to the startup instruction sent from the NW controller 50, the server 20-1 starts the virtual router 22-1 (step S814). When the startup of the virtual router 22-1 is completed, the virtual router 22-1 of the server 30-1 and the virtual router 22-2 of the server 20-2 compare their priorities with each other (step S815).

As a result of the priority comparison, the priority of virtual router 22-1 is higher than that of virtual router 22-2, so virtual router 22-1 sets itself as the master router, and virtual router 22-2 sets itself as the backup router (steps S816, S817). Server 20-1 notifies NW controller 50 that startup of virtual router 22-1 is complete (step S818). Communication unit 51 of NW controller 50 receives the notification from server 20-1. In response to the received notification, communication unit 51 of NW controller 50 transmits a switchover completion report to base station controller 70 indicating that switchover has been completed (step S819).

In addition, in the process of step S807, the instruction unit 521 may send a blocking instruction, including an instruction to change the priority of the virtual router 22-1, to the server 20-1, which is the switching source, via the communication unit 51. The specific process flow in this case has already been described above, so it will not be described here.

In the process of step S807, if the instruction unit 521 transmits a cutoff instruction including an instruction to change the priority of the virtual router 22-1 to the server 20-1, which is the source of switching, via the communication unit 51, the priority of the virtual router 22-1 is lower than the priority of another virtual router 22 (for example, virtual router 22-2). Therefore, in the process of step S807, if the instruction unit 521 transmits a cutoff instruction including an instruction to change the priority of the virtual router 22-1 to the server 20-1, which is the source of switching, via the communication unit 51, and switching back is performed, the instruction unit 521 may include information on the new priority to be set in the start instruction for the virtual router in the process of step S813. For example, the instruction unit 521 may include information indicating a priority (for example, priority "255") such that the priority of the destination virtual router 22 (here, virtual router 22-1) is higher than the priority of the source virtual router 22 (here, virtual router 22-2) in the start instruction. As a result, when the switching destination virtual router 22-1 is started, the priority of the virtual router 22-1 becomes higher than the priority of the other virtual routers 22. This makes it possible to switch back.

The wireless access network system 100d configured as described above can achieve the same effects as the first embodiment.

Furthermore, in the wireless access network system 100d, the OS of the virtual DU21 can also be updated. This makes it possible to process with the latest version even after switching.

Sixth Embodiment
In the first to fifth embodiments, a stateless configuration in which dynamic parameters in a virtual CU or virtual DU are not inherited is shown. In the sixth embodiment, a stateful configuration in which dynamic parameters in a virtual CU or virtual DU are inherited is described. The system configuration of the sixth embodiment is the same as that of the first embodiment. The following description focuses on the differences from the first embodiment.

In the sixth embodiment, live migration is performed to transfer the dynamic parameters in the source virtual CU 31 to the destination virtual CU 31. This makes it possible to transfer the dynamic parameters in the source virtual CU 31 to the destination virtual CU 31.

FIG. 19 is a sequence diagram showing the flow of processing in the wireless access network system 100 in the sixth embodiment. In FIG. 19, the same processes as those in FIG. 4 are denoted by the same reference numerals as in FIG. 4, and the description thereof will be omitted. Note that in the processing in FIG. 19, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 32.

After the processes from step S101 to step S111 are executed, the NW controller 50 migrates the virtual CU 31-1 of the server 30-1 to the server 30-2 by live migration (step S901). As a result, the parameters of the virtual CU 31-1 of the server 30-1 are migrated to the server 30-2 as they are. Then, the processes from step S112 onwards are executed.

The radio access network system 100 in the sixth embodiment configured as described above can achieve the same effects as the first embodiment.

Furthermore, in the radio access network system 100 of the sixth embodiment, parameters within the virtual CU can be carried over to the switching destination.

Seventh Embodiment
In the first to fifth embodiments, a stateless configuration in which dynamic parameters in a virtual CU or virtual DU are not inherited is shown. In the seventh embodiment, a stateful configuration in which dynamic parameters in a virtual CU are inherited is described. The system configuration of the seventh embodiment is the same as that of the second embodiment. The following description focuses on the differences from the second embodiment.

In the seventh embodiment, live migration is performed to transfer the dynamic parameters in the source virtual CU 31 to the destination virtual CU 31. This makes it possible to transfer the dynamic parameters in the source virtual CU 31 to the destination virtual CU 31.

FIG. 20 is a sequence diagram showing the flow of processing in the wireless access network system 100a in the seventh embodiment. In FIG. 20, the same processes as those in FIG. 7 are denoted by the same reference numerals as in FIG. 7, and the description thereof will be omitted. Note that in the processing in FIG. 20, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 32.

After the processes in steps S301, S101 to S111 have been executed, the NW controller 50 migrates the virtual CU 31-1 of the server 30-1 to the server 30-2 by live migration (step S1001). As a result, the parameters of the virtual CU 31-1 of the server 30-1 are migrated to the server 30-2 as is. After that, the processes in steps S112 and onwards are executed.

The wireless access network system 100a in the seventh embodiment configured as described above can achieve the same effects as the second embodiment.

Furthermore, in the wireless access network system 100a in the seventh embodiment, parameters within the virtual CU can be carried over to the switching destination.

Eighth embodiment
In the first to fifth embodiments, a stateless configuration in which dynamic parameters in a virtual CU or virtual DU are not inherited is shown. In the eighth embodiment, a stateful configuration in which the OS of a virtual CU is updated and dynamic parameters in the virtual CU are inherited is described. The system configuration of the eighth embodiment is the same as that of the third embodiment. The following description focuses on the differences from the third embodiment.

In the eighth embodiment, live migration is performed to transfer the dynamic parameters in the source virtual CU 31 to the destination virtual CU 31. This makes it possible to transfer the dynamic parameters in the source virtual CU 31 to the destination virtual CU. Furthermore, in the eighth embodiment, an OS update of the virtual CU is performed in the same way as in the third embodiment.

FIG. 21 is a sequence diagram showing the flow of processing (part 1) of the wireless access network system 100b in the eighth embodiment. In FIG. 21, the same processes as those in FIG. 9 are denoted by the same reference numerals as in FIG. 9, and the description thereof will be omitted. Note that in the processing in FIG. 21, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 32.

After step S101, the processes from step S401 to step S404, the processes from step S104 to step S111, and the processes from step S405 to step S406 have been executed, the NW controller 50 moves the virtual CU 31-1 of the server 30-1 to the server 30-2 by live migration (step S1101). As a result, the parameters of the virtual CU 31-1 of the server 30-1 are moved to the server 30-2 as they are. Then, the processes from step S407 onwards are executed.

22 and 23 are sequence diagrams showing the flow of processing (part 2) of the wireless access network system 100b in the eighth embodiment. Note that in Figs. 22 and 23, a pattern of switching back the OS update destination is explained. In Figs. 22 and 23, the same processes as in Figs. 10 and 11 are denoted with the same reference numerals as in Figs. 10 and 11, and explanations are omitted. Note that in the processing in Figs. 22 and 23, the shutdown instruction is explained as including an instruction to stop the function of the virtual router 32.

After step S101, the processes from step S501 to step S504, the processes from step S104 to step S111, and the processes from step S505 to step S506 have been executed, the NW controller 50 moves the virtual CU 31-1 of the server 30-1 to the server 30-2 by live migration (step S1201). As a result, the parameters of the virtual CU 31-1 of the server 30-1 are moved to the server 30-2 as they are. Then, the processes from step S507 onwards are executed.

In the process of step S507, the instruction unit 521 may send a shutdown instruction including an instruction to change the priority of the virtual router 32-1 to the server 30-1, which is the switching source, via the communication unit 51. The specific flow of the process in this case has already been described above and will not be described here. Furthermore, in the process of step S513, the instruction unit 521 may include information on the newly set priority in the instruction to start the virtual router. The specific flow of the process in this case has already been described above and will not be described here.

The radio access network system 100b in the eighth embodiment configured as described above can achieve the same effects as the third embodiment.

Furthermore, in the wireless access network system 100b in the eighth embodiment, parameters within the virtual CU can be carried over to the switching destination.

Ninth embodiment
In the first to fifth embodiments, a stateless configuration in which dynamic parameters within a virtual CU or virtual DU are not inherited is shown. In the ninth embodiment, a stateful configuration in which dynamic parameters within a virtual DU are inherited is described. The system configuration of the ninth embodiment is the same as that of the fourth embodiment. The following description focuses on the differences from the fourth embodiment.

In the ninth embodiment, live migration is performed to transfer the dynamic parameters within the source virtual DU 21 to the destination virtual DU 21. This makes it possible to transfer the dynamic parameters within the source virtual DU 21 to the destination virtual DU 21.

FIG. 24 is a sequence diagram showing the flow of processing in the wireless access network system 100c in the ninth embodiment. In FIG. 24, the same processes as those in FIG. 14 are denoted by the same reference numerals as in FIG. 14, and the description thereof will be omitted. Note that in the processing in FIG. 24, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 22.

After the processes from step S601 to step S611 are executed, the NW controller 50 migrates the virtual DU 21-1 of the server 20-1 to the server 20-2 by live migration (step S901). As a result, the parameters of the virtual DU 21-1 of the server 20-1 are migrated to the server 20-2 as is. Then, the processes from step S612 onwards are executed.

In addition, in the process of step S612, the instruction unit 521 may send a blocking instruction, including an instruction to change the priority of the virtual router 22-1, to the server 20-1, which is the switching source, via the communication unit 51. The specific process flow in this case has already been described above, so it will not be described here.

The wireless access network system 100c in the ninth embodiment configured as described above can achieve the same effects as the fourth embodiment.

Furthermore, in the radio access network system 100c in the ninth embodiment, parameters within the virtual DU can be carried over to the switching destination.

Tenth Embodiment
In the first to fifth embodiments, a stateless configuration in which dynamic parameters within a virtual CU or virtual DU are not inherited is shown. In the tenth embodiment, a stateful configuration in which dynamic parameters within a virtual DU are inherited is described. The system configuration of the tenth embodiment is the same as that of the fifth embodiment. The following description focuses on the differences from the fifth embodiment.

In the tenth embodiment, live migration is performed to transfer the dynamic parameters in the source virtual DU 21 to the destination virtual DU 21. This makes it possible to transfer the dynamic parameters in the source virtual DU 21 to the destination virtual DU 21.

FIG. 25 is a sequence diagram showing the flow of processing (part 1) of the wireless access network system 100d in the tenth embodiment. In FIG. 25, the same processes as those in FIG. 16 are denoted by the same reference numerals as in FIG. 16, and the description thereof will be omitted. Note that in the processing of FIG. 25, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 22.

After step S601, the processes from step S701 to step S704, the processes from step S604 to step S611, and the processes from step S705 to step S706 have been executed, the NW controller 50 moves the virtual DU 21-1 of the server 20-1 to the server 20-2 by live migration (step S1401). As a result, the parameters of the virtual DU 21-1 of the server 20-1 are moved to the server 20-2 as is. Then, the processes from step S707 onwards are executed.

26 and 27 are sequence diagrams showing the flow of processing (part 2) of the wireless access network system 100d in the tenth embodiment. In Figs. 26 and 27, the same processes as those in Figs. 17 and 18 are denoted with the same reference numerals as those in Figs. 17 and 18, and the description thereof will be omitted. Note that in the processing of Figs. 26 and 27, the explanation will be given assuming that the cutoff instruction includes an instruction to stop the function of the virtual router 22.

After step S601, the processes from step S801 to step S804, the processes from step S804 to step S811, and the processes from step S805 to step S806 have been executed, the NW controller 50 moves the virtual DU 21-1 of the server 20-1 to the server 20-2 by live migration (step S1501). As a result, the parameters of the virtual DU 21-1 of the server 20-1 are moved to the server 20-2 as is. Then, the processes from step S807 onwards are executed.

In the process of step S807, the instruction unit 521 may send a shutdown instruction including an instruction to change the priority of the virtual router 22-1 to the server 20-1, which is the switching source, via the communication unit 51. The specific flow of the process in this case has already been described above and will not be described here. Furthermore, in the process of step S813, the instruction unit 521 may include information on the newly set priority in the instruction to start the virtual router. The specific flow of the process in this case has already been described above and will not be described here.

The radio access network system 100d of the tenth embodiment configured as described above can achieve the same effects as the fifth embodiment.

Furthermore, in the radio access network system 100d in the tenth embodiment, parameters within the virtual DU can be carried over to the switching destination.

Some of the functions of the above-mentioned servers 20, 20-1, 20-2, servers 30-1, 30-2, NW controller 50, and base station controller 70 may be realized by a computer. In this case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to realize the functions. Note that the term "computer system" here includes hardware such as an OS and peripheral devices. Also, "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc-ROMs), as well as storage devices such as hard disks built into computer systems.

Furthermore, "computer-readable recording medium" may include something that dynamically holds a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, or something that holds a program for a fixed period of time, such as volatile memory within a computer system that serves as a server or client in that case. Furthermore, the above program may be one that realizes part of the functions described above, or may be one that can realize the functions described above in combination with a program already recorded in the computer system, or may be one that is realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

　Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs that do not deviate from the gist of the present invention.

This invention can be applied to network control technology in wireless access networks.

10...Radio station, 20, 20-1, 20-2, 30-1, 30-2...Server, 21-1, 21-2...Virtual DU, 31-1, 31-2...Virtual CU, 22-1, 22-2, 32-1, 32-2...Virtual router, 40...5GC, 50...NW controller, 51...Communication unit, 52...Control unit, 521...Instruction unit, 522...Communication control unit, 60...Network, 65...MEC, 67...MEC controller, 70...Base station controller, 100, 100a, 100b, 100c, 100d...Radio access network system

Claims

a control unit that uses a protocol for making default gateways redundant in a source server and a destination server that realize a forwarding function and a base station function in a wireless access network by using a virtualization technology, thereby grouping the forwarding function realized in the source server and the forwarding function realized in the destination server, and switches the route by stopping the forwarding function realized in the source server or by changing a priority value and transitioning it to a standby state;
A control device comprising:
After grouping between the forwarding function realized by the switching source server and the forwarding function realized by the switching destination server is completed, the control unit stops the forwarding function realized by the switching source server or changes a priority value to transition the forwarding function to a standby state.
The control device according to claim 1 .
The control unit performs switching back to the original route after completing an update of the operating system of the base station function after the route switching.
The control device according to claim 1 or 2.
the source server transfers parameters within the base station function to the destination server by live migration;
The control device according to claim 1 or 2.
The protocol for making the default gateway redundant is VRRP (Virtual Router Redundancy Protocol).
The control device according to claim 1 or 2.
The base station function is either a CU (Central Unit) that processes data or a DU (Distributed Unit) that processes radio signals.
The control device according to claim 1 or 2.
A switching control method that uses virtualization technology to group the forwarding function realized by the source server and the forwarding function realized by the destination server by using a protocol that makes the default gateway redundant in the source server and the destination server that realizes the forwarding function and the base station function in the wireless access network, and switches the route by stopping the forwarding function realized by the source server or changing the priority value and transitioning to a standby state.