WO2024013816A1

WO2024013816A1 - Radio communication system, radio communication method, centralized control device, and centralized control program

Info

Publication number: WO2024013816A1
Application number: PCT/JP2022/027293
Authority: WO
Inventors: 純一岩谷; ヒランタアベセカラ; 裕介淺井; 朗岸田; 花絵大谷; 信也大槻; 陸大宮; 泰司鷹取
Original assignee: 日本電信電話株式会社
Priority date: 2022-07-11
Filing date: 2022-07-11
Publication date: 2024-01-18

Abstract

A radio communication system according to an embodiment comprises a centralized control device that performs a centralized control of multiple base stations including base stations capable of performing multi-link transmissions together with radio terminals. The radio communication system is characterized in that the centralized control device has: a distribution control unit that performs such a control that distributes more radio resources to the radio devices connected to radio terminals having high priority levels among the multiple radio terminals than to the other radio devices; and a ratio control unit that performs such a control that increases the ratio in which the radio terminals having the high priority levels uses the radio resources for the radio devices for which the distribution control unit controls the distribution of the radio resources.

Description

Wireless communication system, wireless communication method, central control device and central control program

The present invention relates to a wireless communication system, a wireless communication method, a centralized control device, and a centralized control program.

For example, in IEEE802.11 (wireless LAN), a single device is equipped with multiple different wireless LAN interfaces and has a function of establishing multiple transmission paths, and such a device is called a multilink device (MLD). It is called.

Multilink transmission (multilink function) includes, for example, an AP MLD equipped with multiple base station (AP: Access Point) functions in one housing, and multiple wireless terminals (STA: Station) installed in one housing. This is wireless communication in which a link is formed between each STA and MLD.

Therefore, in multi-link transmission, it is possible to improve the reliability of data reception by transmitting the same data in parallel, or to improve the transmission efficiency by transmitting different data.

Additionally, RATOP (Resource allocation based on Area Throughput Optimization Policy) is known as a method for centrally controlling the frequency bandwidth and channels used by wireless LAN APs to maximize the effective throughput of the entire system. For example, see Non-Patent Document 1).

In RATOP, a centralized control device grasps the status of each AP and allocates radio resources such as frequency channels and bandwidths that each AP should use.

For example, in RATOP, as an evaluation index for radio resource allocation, the amount of traffic that can be sent out based on the allocated radio resources (channel/bandwidth) is calculated based on the estimated maximum traffic amount (accommodated traffic amount) of each AP. The ratio (utility function) of the estimated amount (traffic amount that can be sent) is defined. Then, the central control device performs control to maximize the total value of the utility functions.

The present invention enables centralized control of wireless resource allocation for a system including a base station capable of multi-link transmission so as to expand communication capacity according to the priority of wireless terminals connected to the base station. The object of the present invention is to provide a wireless communication system, a wireless communication method, a centralized control device, and a centralized control program.

A wireless communication system according to an embodiment of the present invention includes a base station capable of multi-link transmission with a wireless terminal, and includes a plurality of base stations capable of communicating with the wireless terminal for each wireless device accommodated, and the base station. In a wireless communication system comprising a central control device that centrally controls each station, the central control device allocates wireless resources to the wireless device to which a high priority wireless terminal among a plurality of wireless terminals connects. an allocation control unit that controls allocation to a larger amount than the wireless device; and a ratio at which the wireless terminal with the higher priority uses wireless resources with respect to the wireless device to which the allocation control unit has controlled the allocation of wireless resources. and a ratio control section that controls the ratio to increase.

Furthermore, the wireless communication method according to an embodiment of the present invention includes a base station that is capable of multi-link transmission with a wireless terminal, and each wireless device that accommodates a plurality of base stations that can communicate with the wireless terminal. In a wireless communication method that performs centralized control, a distribution control step of controlling such that more wireless resources are allocated to the wireless device to which a wireless terminal with a higher priority among a plurality of wireless terminals connects than to other wireless devices. and a ratio control step of controlling the radio terminals having a high priority to use radio resources at a high ratio with respect to the radio devices whose radio resource allocation has been controlled.

Further, the centralized control device according to an embodiment of the present invention includes a base station capable of multi-link transmission with wireless terminals, and each wireless device accommodated has a plurality of base stations capable of communicating with the wireless terminal. In a centralized control device that performs centralized control, an allocation control unit that controls to allocate more radio resources to the wireless device to which a wireless terminal with a higher priority among a plurality of wireless terminals connects than to other wireless devices. and a ratio control unit that controls the radio terminals having a high priority to use a large proportion of radio resources for the radio devices to which the allocation control unit has controlled the radio resource allocation. shall be.

According to the present invention, for a system including a base station capable of multi-link transmission, allocation of radio resources is centrally controlled so as to expand communication capacity according to the priority of radio terminals connected to the base station. I can do it.

1 is a diagram illustrating a configuration example of a wireless communication system according to an embodiment. FIG. 2 is a functional block diagram illustrating functions of a central control device according to an embodiment. 1 is a flowchart illustrating an example of the operation of a wireless communication system according to an embodiment. FIG. 3 is a diagram illustrating another configuration example of a wireless communication system according to an embodiment. FIG. 2 is a diagram illustrating a hardware configuration of a central control device according to an embodiment. 1 is a diagram illustrating a configuration example of a wireless communication system that does not include a multilink device. FIG. 3 is a diagram showing a specific example of a RATOP algorithm executed by the central control device.

First, the background of the invention will be explained. FIG. 6 is a diagram illustrating a configuration example of a wireless communication system 1 that does not include a multilink device. The wireless communication system 1 is, for example, a wireless LAN system that does not include an AP MLD and a STA MLD, and the above-mentioned RATOP is applied.

As shown in FIG. 6, the wireless communication system 1 includes, for example, a plurality of base stations 2, a central control device 3, and a plurality of wireless terminals 4 connected to a network 100. Each base station 2 accommodates a plurality of wireless terminals 4 by being centrally controlled by a central control device 3 . Hereinafter, a base station may be referred to as an AP.

The centralized control device 3 performs RATOP control for a plurality of base stations 2. At this time, it is assumed that the control index is the utility function U (=corresponding to satisfaction) shown in equation (1) below.

a: AP identifier b: Bandwidth c: Channel (primary channel)
R: Data rate (MCS)

The expected throughput of AP (a) depends on the channel usage status of other APs. Further, the accommodated traffic amount (depending on the amount of generated data) is, for example, the estimated maximum traffic value of AP (a) shown in the following equation (2).

Then, the centralized control device 3 performs processing to maximize the sum ΣU of the utility functions U according to the following algorithm.

RATOP algorithm:
(A): The central control device 3 "tentatively allocates" the channel/bandwidth used by each AP according to predetermined rules.
(B): The centralized control device 3 calculates the sum ΣU of the utility functions U of each AP in the above case (A).
(C): The centralized control device 3 reallocates channels and bandwidths to APs with a low utility function U, and performs control so that ΣU does not decrease. Then, the centralized control device 3 repeats the step (C) within a range of predetermined conditions.

FIG. 7 is a diagram showing a specific example of the RATOP algorithm executed by the central control device 3. As shown in FIG. 7, the central control device 3 performs phase I (initial calculation) and phase II (optimization) processing.

In Phase I, the central control device 3 selects one AP as AP-a (S100), selects a bandwidth b that can be allocated to AP-a (S102), and selects a bandwidth b that can be allocated to AP-a. Channel c is selected (S104), and utility function U of AP-a is calculated (S106).

Then, the centralized control device 3 executes the process of S104 and the process of S106 for all channels c, and repeats the process for all bandwidths b.

Next, the centralized control device 3 selects the combination (b, c) that maximizes the utility function U (S108), and repeats the process for all APs.

In phase II, the centralized control device 3 selects, for example, an AP with a small utility function U, and then selects the combination (parameters) of (b, c) in which the utility function U becomes maximum and the sum ΣU of the utility functions U does not deteriorate. The process of selecting is repeated (S110).

Then, the centralized control device 3 sets the combinations (b, c) selected by each AP as the allocated bandwidth and channel after control.

Next, a wireless communication system 10 according to an embodiment will be described. FIG. 1 is a diagram illustrating a configuration example of a wireless communication system 10 according to an embodiment. The wireless communication system 10 is a wireless LAN system including an AP MLD and a STA MLD, and the above-mentioned RATOP is applied to the MLD.

As shown in FIG. 1, the wireless communication system 10 includes, for example, base stations 20-1, 20-2, and 30 connected to a network 100, a central control device 40, and a plurality of

wireless terminals

50 and 52. Hereinafter, when one of the plurality of configurations, such as base stations 20-1 and 20-2, is not specified, it will simply be abbreviated as base station 20 or the like.

Each of the base stations 20-1, 20-2, and 30 accommodates a plurality of

wireless terminals

50 and 52 by being centrally controlled by the central control device 40. Hereinafter, the base stations 20-1, 20-2, and 30 may be described as APs.

The wireless terminals 50 are STA and MLD, respectively. Each of the wireless terminals 52 is a terminal that does not have a multilink function.

The base stations 20-1 and 20-2 are each AP MLD, and have an MLD section 200 and

wireless devices

202 and 204.

The MLD unit 200 transmits and receives signals to and from the central control device 40 and the

wireless devices

202 and 204, and performs processing for the base station 20 to function as an AP MLD using the

wireless devices

202 and 204.

The wireless device 202 has a function as a base station (AP) that performs wireless communication using, for example, a 5 GHz band. The wireless device 204 has a function as a base station (AP) that performs wireless communication using, for example, a 6 GHz band.

The base station 30 has one wireless device 300 and does not have a multilink function. The wireless device 300 has a function as a base station (AP) that performs wireless communication using, for example, a 5 GHz band.

The centralized control device 40 centrally controls the base stations 20-1, 20-2, and 30 by, for example, wireless communication.

FIG. 2 is a functional block diagram illustrating functions of the central control device 40 according to an embodiment. As shown in FIG. 2, the centralized control device 40 includes, for example, a wireless communication section 41, a collection section 42, a selection section 43, a utility function calculation section 44, a distribution control section 45, a ratio control section 46, and a main control section 47.

The wireless communication unit 41 transmits and receives signals to and from the base stations 20-1, 20-2, and 30 by wireless communication, respectively.

The collection unit 42 collects information regarding the base stations 20-1, 20-2, and 30 via the wireless communication unit 41, and outputs the collected information to the selection unit 43 and the utility function calculation unit 44. For example, the collection unit 42 collects information (traffic information, etc.) regarding each of the

wireless devices

202, 204, and 300. The collection unit 42 also collects information indicating priorities determined for the plurality of

wireless terminals

50 and 52 connected to the

wireless devices

202, 204, and 300, respectively.

The selection unit 43 selects a wireless terminal with a high priority (wireless terminal subject to priority control) based on the information collected by the collection unit 42, and sends information indicating the selection result to the utility function calculation unit 44 and distribution control. It is output to section 45.

Based on the information collected by the collection unit 42 (and the information indicating the selection result by the selection unit 43), the utility function calculation unit 44 transmits data using the allocated channel and bandwidth to each of the

wireless devices

202, 204, and 300. The ratio of the possible traffic amount to the accommodated traffic amount is calculated as a utility function, and the calculated utility function is output to the distribution control unit 45.

The accommodated traffic amount (data generation amount) depends on the traffic distribution ratio to each of the

wireless devices

202, 204, and 300. For example, the utility function calculation unit 44 assumes, based on the information collected by the collection unit 42, the accommodated traffic amount to be distributed in proportion to the transmittable traffic amount or bandwidth of each of the

wireless devices

202, 204, and 300, for example.

The distribution control unit 45 allocates more wireless resources to a wireless device (such as one of the

wireless devices

202, 204, 300, etc.) to which a wireless terminal with a higher priority among the multiple wireless terminals is connected than to other wireless devices. Control is performed to allocate it. For example, the allocation control unit 45 controls the allocation of radio resources calculated based on the utility function calculated by the utility function calculation unit 44.

The ratio control unit 46 controls the radio devices whose radio resource allocation has been controlled by the allocation control unit 45 so that a radio terminal with a high priority uses a radio resource at a high ratio.

The main control section 47 controls each section constituting the central control device 40. For example, when a wireless terminal with a high priority is a multilink device, the main control unit 47 controls the distribution control unit 45, the ratio control unit 46, and the wireless Controls the communication section 41.

In addition, when a wireless terminal with a high priority is a multilink device, and when there are variations in capacity and quality among the frequency bands used by the wireless terminal, the main control unit 47 controls the wireless terminal to which the wireless terminal connects. control so that high-quality frequency bands are used preferentially. Furthermore, the main control unit 47 performs control to increase the allocation ratio of wireless resources to wireless devices to which wireless terminals with high priority connect.

In other words, the centralized control device 40 calculates the allocation of radio resources based on the utility function of each of the

wireless devices

202, 204, and 300, and assigns the calculated allocation to the base station to which the high-priority wireless terminal is connected. control to allocate more radio resources.

Furthermore, the central control device 40 performs control to increase the usage ratio of radio resources in the radio devices for high priority radio terminals.

Next, an example of the overall operation of the wireless communication system 10 will be described. FIG. 3 is a flowchart illustrating an example of the operation of the wireless communication system 10 according to one embodiment.

First, each of the base stations 20-1, 20-2, and 30 determines whether or not there is an instruction to collect information from the central control device 40 (S200), and if there is an instruction (S200: Yes), the base stations 20-1, 20-2, and 30 If there is no instruction (S200: No), the process of S200 is repeated.

In step 202 (S202), the base stations 20-1, 20-2, and 30 transmit the traffic status and the like of the

wireless devices

202, 204, and 300 that they accommodate to the central control device 40.

In step 204 (S204), the base stations 20-1, 20-2, and 30 issue a control instruction (or It is determined whether there is a control instruction (to update the traffic distribution) from the central control device 40. When the base stations 20-1, 20-2, and 30 determine that there is a control instruction (S204: Yes), the process proceeds to S206, and when it is determined that there is no control instruction (S204: No), the process proceeds to S200. Return to processing.

In step 206 (S206), the base stations 20-1, 20-2, and 30 perform change control to change the bandwidth b and channel c (parameters) (or control to update the traffic allocation).

Next, the wireless communication system according to one embodiment will be specifically described using another configuration example. FIG. 4 is a diagram illustrating another configuration example of the wireless communication system according to one embodiment. Another configuration example of the wireless communication system is a wireless LAN system including an AP MLD and a STA MLD, and the above-mentioned RATOP is applied to the MLD.

Note that in the wireless communication system shown in FIG. 4, substantially the same configuration as the wireless communication system 10 shown in FIG. 1 is given the same reference numeral.

As shown in FIG. 4, another configuration example of the wireless communication system includes base stations 20-1 and 20-2 connected to a network 100, and a central control device 40, for example. Each of the base stations 20-1 and 20-2 accommodates a plurality of wireless terminals by being centrally controlled by the central control device 40.

Here, the base station 20-1, which is an AP MLD, accommodates wireless terminals 50-1 to 50-3, which are STA MLDs, and a wireless terminal 52-1, which is an STA without a multilink function. Furthermore, the base station 20-2, which is an AP MLD, accommodates a wireless terminal 50-4, which is an STA MLD, and a wireless terminal 52-2, which is an STA without a multilink function.

Note that the wireless terminals 50-1 to 50-4 each include

wireless devices

502 and 504. Furthermore, each of the wireless terminals 52-1 and 52-2 includes a wireless device 522.

The wireless device 502 and the wireless device 522 correspond to the communication method of the wireless device 202 provided in the base station 20, and perform wireless communication with the wireless device 202 using radio waves in the 5 GHz band. The wireless device 504 corresponds to the communication method of the wireless device 204 provided in the base station 20, and performs wireless communication with the wireless device 204 using radio waves in the 6 GHz band.

For example, the central control device 40 performs control to allocate a large amount of wireless resources to the AP MLD to which the specific STA MLD is connected, in order to perform priority control that prioritizes wireless communication of the specific STA MLD.

Thereafter, the centralized control device 40 performs control to further increase the radio resource allocation ratio to a specific STA MLD in the AP MLD to which a large amount of radio resources have been allocated.

Specifically, the base stations 20-1 and 20-2 collect the traffic status of each of the

wireless terminals

50 and 52 they accommodate, and transmit the collected information to the central control device 40.

The centralized control device 40 selects wireless terminals to be subject to priority control based on information received from the base stations 20-1 and 20-2. Here, the centralized control device 40 selects, for example, the wireless terminal 50-1 as a wireless terminal to be subject to priority control.

Next, the centralized control device 40 calculates a utility function for each of the base stations 20-1 and 20-2, and applies the utility function to the base station 20-1 to which the wireless terminal 50-1 to be subject to priority control is connected. , performs control so that it has more radio resources than the base station 20-2. The centralized control device 40 may perform control to increase the amount of traffic accommodated by the

wireless devices

202 and 204 included in the base station 20-1 and calculate the utility function.

Then, the centralized control device 40 transmits an instruction to the base station 20-1 for the

wireless devices

202 and 204 to increase the wireless resources (airtime usage) used by the wireless terminal 50-1.

The

wireless devices

202 and 204 included in the base station 20-1 perform processing to increase the allocation ratio of wireless resources to the wireless terminal 50-1.

In other words, the wireless terminal 50-1 can preferentially use wireless resources in the 6 GHz band and 5 GHz band over other wireless terminals.

In addition, for priority control that prioritizes wireless communication of a specific STA MLD, the centralized control device 40 performs high-quality Control is performed to preferentially use a frequency band (for example, a 6 GHz band with high transmission efficiency).

Thereafter, the central control device 40 increases the allocation of radio resources to the AP MLD to which the specific STA MLD is connected, and allocates traffic to wireless devices (for example, the wireless device 204) in high-quality frequency bands within the AP MLD. Perform control to further increase the ratio.

wireless terminals

Thereafter, the centralized control device 40 controls transmission in the 6 GHz band, for example, based on information such as the surrounding environment (radio wave interference, etc.), frequency band, and bandwidth of the base station 20-1 to which the wireless terminal 50-1 is connected. It is determined that there is sufficient capacity and that the 6GHz band can be used with high quality.

At this time, the central control device 40 determines a frequency band (eg, 6 GHz band) to be preferentially used by the base station 20-1 to which the wireless terminal 50-1 is connected.

Then, the centralized control device 40 performs control to increase the allocation ratio of radio resources to the radio device 204 provided in the base station 20-1 rather than to the radio device 204 provided in the base station 20-2. At this time, the centralized control device 40 may calculate the utility function by increasing the amount of accommodated traffic for the wireless device 204 included in the base station 20-1.

When the centralized control device 40 transmits an instruction to the base station 20-1 to increase the allocation ratio of the traffic amount by the wireless device 204, the base station 20-1 increases the traffic allocation ratio of the wireless device 204 to the wireless terminal 50-1. Increase the amount allocation ratio.

In other words, the wireless terminal 50-1 can preferentially use 6 GHz band wireless resources over other wireless terminals.

In this way, the wireless communication system according to one embodiment allocates more wireless resources to the wireless device to which a wireless terminal with a high priority connects than to other wireless devices, and the wireless terminal with a high priority allocates wireless resources to the wireless device to which the wireless terminal connects. control so that the ratio of use is large. Therefore, in a wireless communication system according to an embodiment, wireless resources are allocated to a system including a base station capable of multi-link transmission so as to expand communication capacity according to the priority of wireless terminals connecting to the base station. Allocation can be centrally controlled.

Note that each function of the central control device 40 may be partially or entirely configured by hardware such as a PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array), or may be executed by a processor such as a CPU. It may also be configured as a program.

For example, the central control device 40 can be realized using a computer and a program, and the program can be recorded on a storage medium or provided through a network.

FIG. 5 is a diagram illustrating the hardware configuration of the central control device 40 according to one embodiment. As shown in FIG. 5, the centralized control device 40 has an input section 400, an output section 410, a communication section 420, a CPU 430, a memory 440, and an HDD 450 connected to each other via a bus 460, and has a function as a computer. The central control device 40 is also capable of inputting and outputting data to and from a computer-readable storage medium 470.

The input unit 400 is, for example, a keyboard and a mouse. The output unit 410 is, for example, a display device such as a display.

The communication unit 420 is a communication interface that performs wireless communication using, for example, a wireless LAN.

The CPU 430 controls each part of the central control device 40 and performs predetermined processing. The memory 440 and HDD 450 store data and the like.

The storage medium 470 is capable of storing programs and the like that execute the functions of the central control device 40. Note that the architecture configuring the centralized control device 40 is not limited to the example shown in FIG. 5.

DESCRIPTION OF SYMBOLS 10... Wireless communication system, 20-1, 20-2, 30... Base station, 40... Central control device, 41... Wireless communication unit, 42... Collection unit, 43... Selection unit, 44... Utility function calculation unit, 45... Distribution control unit, 46... Ratio control unit, 47... Main control unit, 50, 50-1 to 50-4, 52, 52- 1, 52-2... Wireless terminal, 100... Network, 200... MLD section, 202, 204, 300... Wireless device, 400... Input section, 410... Output section, 420 ...Communication department, 430...CPU, 440...Memory, 450...HDD, 460...Bus, 470...Storage medium, 502, 504, 522...Wireless device

Claims

A wireless device including a base station capable of multi-link transmission with a wireless terminal, a plurality of base stations capable of communicating with the wireless terminal for each wireless device accommodated, and a central control device that centrally controls each of the base stations. In communication systems,
The central control device includes:
an allocation control unit that controls to allocate more radio resources to the wireless device to which a wireless terminal with a high priority among the plurality of wireless terminals connects than to other wireless devices;
and a ratio control unit configured to control the wireless devices with respect to which the allocation control unit has controlled the allocation of radio resources so that the wireless terminals with the high priority use a large proportion of the radio resources. Wireless communication system.
further comprising a utility function calculation unit that calculates, as a utility function, a ratio of the amount of traffic that can be transmitted to the amount of traffic that can be accommodated based on the assigned channel and bandwidth for each of the wireless devices;
The distribution control section includes:
The wireless communication system according to claim 1, wherein allocation of wireless resources calculated based on the utility function is controlled.
If the wireless terminal with a high priority is a multilink device, a main control unit that controls the distribution control unit and the ratio control unit so that the wireless device with a high capacity or transmission efficiency is used preferentially. The wireless communication system according to claim 1 or 2, characterized in that it comprises:
In a wireless communication method that includes a base station capable of multi-link transmission with a wireless terminal and centrally controls each of a plurality of base stations capable of communicating with the wireless terminal for each wireless device accommodated,
a distribution control step of controlling to allocate more radio resources to the wireless device to which a wireless terminal with a high priority among the plurality of wireless terminals connects than to the other wireless devices;
and a ratio control step of controlling the radio device whose radio resource allocation has been controlled so that the radio terminal with the higher priority uses a radio resource at a higher ratio.
In a centralized control device that includes a base station capable of multi-link transmission with a wireless terminal and centrally controls each of a plurality of base stations that can communicate with the wireless terminal for each wireless device it accommodates,
an allocation control unit that controls to allocate more radio resources to the wireless device to which a wireless terminal with a high priority among the plurality of wireless terminals connects than to other wireless devices;
and a ratio control unit configured to control the wireless devices with respect to which the allocation control unit has controlled the allocation of radio resources so that the wireless terminals with the high priority use a large proportion of the radio resources. Central control device.
Further comprising a utility function calculation unit that calculates, as a utility function, a ratio of the amount of traffic that can be transmitted to the amount of traffic that can be accommodated based on the allocated channel and bandwidth for each of the wireless devices,
The distribution control section includes:
The centralized control device according to claim 5, wherein the centralized control device controls allocation of radio resources calculated based on the utility function.
If the wireless terminal with a high priority is a multilink device, a main control unit that controls the distribution control unit and the ratio control unit so that the wireless device with a high capacity or transmission efficiency is used preferentially. The centralized control device according to claim 5 or 6, characterized in that it has:
A central control program for causing a computer to function as each part of the central control device according to claim 5 or 6.