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

Abstract

A wireless communication system according to one embodiment comprises: a collection unit that collects capability information of each of MLD wireless terminals, an MLD base station, wireless terminals, and a base station; a temporary allocation unit that temporarily allocates a belonging destination to each of the MLD wireless terminals and the wireless terminals such that each is accommodated by either the MLD base station or the base station; an estimation unit that estimates the throughput of each of the MLD wireless terminals and the wireless terminals on the basis of the capability information and the temporarily allocated belonging destination; a temporary re-allocation unit that temporarily re-allocates the belonging destination to the MLD wireless terminal or the wireless terminal the estimated throughput of which is less than a predetermined threshold; and a processing unit that performs processing for determining a final belonging destination when the throughput of each of the MLD wireless terminals and the wireless terminals satisfies a predetermined condition by the temporarily re-allocated belonging destination.

Description

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

[0001] The present invention relates to a wireless communication system, a control device, a wireless communication method, and a wireless communication program.

[0002] For example, the IEEE 802.11be standard is scheduled to define multi-link transmission (MLO: Multi-Link Operation) that transmits frames using multiple transmission paths with different frequency channels (see, for example, Non-Patent Documents 1 and 2).

[0003] In MLO, a single device is equipped with a plurality of different wireless interfaces and employs a function for establishing a plurality of transmission paths, and such a device is called a multi-link device (MLD).

[0004] Multi-link transmission is wireless communication that forms links between, for example, an MLD AP (Access Point) that has multiple base station functions in one housing and an MLD STA (Station) that has multiple wireless terminals in one housing.

[0005] Therefore, in multi-link transmission, it is expected that throughput will be improved and delay time will be reduced by transmitting different frames using multiple transmission paths.

[0006] On the other hand, the IEEE 802.11 standard does not specify a method for determining which base station a wireless terminal should belong to (determining the base station to belong to). For example, in an environment where a wireless terminal can connect to multiple base stations, the method for selecting the base station to which the wireless terminal should belong is left to the implementation of each vendor.

[0007] For example, the following four methods are commonly used to select a base station to which a wireless terminal is to belong.

[0008] 1) The wireless terminal selects the first base station it detects. 2) The base station with the strongest signal is selected. 3) The base station with the fewest wireless terminals already associated with it is selected. 4) A base station is randomly selected from the multiple detected base stations.

[0009] IEEE Standard for Information Technology-Telecommunications and Information Exchange between Systems Local and Metropolitan Area Networks-Specific Requirements, Part 11: Wireless LAN Medium Access Control(MAC) and Physical Layer (PHY) Specifications, IEEE Std 802.11TM-2020, (Revision of IEEE Std 802.11-2016), P.255-256, P.1672-1678IEEE P802.11beTM D3.0, Draft Standard for Information technology- Telecommunications and information exchange between systems Local and metropolitan area networks- Specific requirements, Part 11: Wireless LAN Medium Access Control(MAC) and Physical Layer (PHY) Specifications, Amendment 8: Enhancements for extremely high throughput (EHT), IEEE P802.11beTM / D3.0, January 2023, (amendment to IEEE P802.11-REVme / TM1.3), P.479-586

[0010] Conventionally, in an environment where wireless terminals and base stations that support MLO and wireless terminals and base stations that do not support MLO coexist, if a wireless terminal that supports MLO selects a base station that does not support MLO as its destination, it may not be able to use the MLO function effectively.

[0011] The present invention aims to provide a wireless communication system, a control device, a wireless communication method, and a wireless communication program that can improve throughput even in an environment where wireless terminals and base stations that support MLO and wireless terminals and base stations that do not support MLO are mixed.

[0012] A wireless communication system according to one embodiment of the present invention includes one or more MLD base stations capable of accommodating MLD wireless terminals that support MLO and wireless terminals that do not support MLO, one or more base stations that can accommodate only wireless terminals that do not support MLO, and a control device that controls the MLD base stations and the base stations, wherein the control device includes a collection unit that collects capability information that indicates wireless communication capabilities of the MLD wireless terminals, the MLD base stations, the wireless terminals, and the base stations, and a return unit that returns the MLD wireless terminals and the wireless terminals so that they can be accommodated by either the MLD base station or the base station. The wireless terminal device is characterized by comprising: a provisional allocation unit that provisionally allocates a destination; an estimation unit that estimates the throughput of each of the MLD wireless terminals and the wireless terminals based on the capability information collected by the collection unit and the destination provisionally allocated by the provisional allocation unit; a reallocation unit that provisionally reallocates a destination to the MLD wireless terminal or the wireless terminal whose throughput estimated by the estimation unit is less than a predetermined threshold; and a processing unit that performs processing to determine the destination provisionally reallocated by the reallocation unit as a final destination when the throughput of each of the MLD wireless terminals and the wireless terminals satisfies a predetermined condition due to the destination provisionally reallocated by the reallocation unit.

[0013] Furthermore, a control device according to one embodiment of the present invention is a control device that controls one or more MLD base stations that can accommodate MLD wireless terminals that support MLO and wireless terminals that do not support MLO, and one or more base stations that can accommodate only wireless terminals that do not support MLO, and includes a collection unit that collects capability information that indicates wireless communication capabilities of the MLD wireless terminals, the MLD base stations, the wireless terminals, and the base stations, a provisional allocation unit that provisionally allocates a destination to each of the MLD wireless terminals and the wireless terminals so that either the MLD base station or the base station can accommodate them, and a control unit that controls the collection unit to collect capability information that indicates wireless communication capabilities of each of the MLD wireless terminals, the MLD base stations, the wireless terminals, and the base stations. and a processing unit that performs processing to determine the assignment destination reallocated by the reallocated unit as a final assignment destination when the throughput of each of the MLD wireless terminal and the wireless terminals satisfies a predetermined condition due to the assignment destination reallocated by the reallocated unit.

[0014] Furthermore, a wireless communication method according to one embodiment of the present invention is a wireless communication method in which a control device controls one or more MLD base stations capable of accommodating MLD wireless terminals that support MLO and wireless terminals that do not support MLO, and one or more base stations that can accommodate only wireless terminals that do not support MLO, the method comprising the steps of: collecting capability information indicating wireless communication capabilities of the MLD wireless terminals, the MLD base stations, the wireless terminals, and the base stations; provisionally assigning a destination to each of the MLD wireless terminals and the wireless terminals so that they are accommodated by either the MLD base station or the base station; and determining whether the capability information collected by the collecting step is correct. and a processing step of performing a process of determining the assignment destination tentatively assigned by the re-allocation step as a final assignment destination when the throughput of each of the MLD wireless terminal and the wireless terminal tentatively assigned by the re-allocation step satisfies a predetermined condition.

[0015] According to the present invention, it is possible to improve throughput even in an environment where wireless terminals and base stations that support MLO and wireless terminals and base stations that do not support MLO coexist.

[0016] 1 is a diagram illustrating an example of the configuration of a wireless communication system according to an embodiment; FIG. 2 is a functional block diagram illustrating functions possessed by a control device according to an embodiment; FIG. 3 is a flowchart illustrating an example of the operation of a wireless communication system according to an embodiment; FIG. 4 is a graph illustrating an example of the results of improving throughput in a wireless communication system according to an embodiment; FIG. 5 is a diagram illustrating an example of the hardware configuration of a control device according to an embodiment; FIG. 6(a) is a diagram schematically illustrating a state in which a wireless terminal selects and associates with a base station that detects the strongest signal strength; and FIG. 6(b) is a diagram schematically illustrating a state in which a wireless terminal selects and associates with a base station based on wireless communication capability and distance.

[0017] First, the background to the invention will be described. Fig. 6 is a diagram schematically showing the association of a wireless terminal with a base station in an environment where wireless terminals and base stations that support MLO and wireless terminals and base stations that do not support MLO coexist. Fig. 6(a) is a diagram schematically showing a state in which a wireless terminal selects and associates with a base station that detects the strongest signal strength. Fig. 6(b) is a diagram schematically showing a state in which a wireless terminal selects and associates with a base station based on wireless communication capability and distance.

[0018] Here, it is assumed that the base station 10 is a base station that does not support MLO and performs wireless communication using only radio waves in the 2 GHz band, and the wireless terminal 100 is a wireless terminal that does not support MLO and performs wireless communication using only radio waves in the 2 GHz band.

[0019] Furthermore, the base station 20 is assumed to be a base station that supports MLO, which performs wireless communication using radio waves in the 2 GHz and 5 GHz bands, for example. The wireless terminal 200 is assumed to be a wireless terminal that supports MLO, which performs wireless communication using radio waves in the 2 GHz and 5 GHz bands, for example. The frequency band of the radio waves used by the base station 20 and the wireless terminal 200 may be 920 MHz or 6 GHz, or may be 28 GHz or 60 GHz (millimeter waves).

[0020] Hereinafter, the base station 10 etc. that does not support MLO will be simply referred to as a base station, and the base station 20 etc. that supports MLO will be referred to as an MLD base station. Also, the wireless terminal 100 etc. that does not support MLO will be simply referred to as a wireless terminal, and the wireless terminal 200 etc. that supports MLO will be referred to as an MLD wireless terminal.

[0021] Furthermore, when there is no distinction between base station 10 and base station 20, the base station is referred to as an AP (Access Point), and when there is no distinction between wireless terminal 100 and wireless terminal 200, the wireless terminal is referred to as an STA (Station).

[0022] 6A, for example, the wireless terminal 100 may select the base station 20, which is the AP that is closest to the wireless terminal 100 and has the highest RSSI, as its destination. Furthermore, the wireless terminal 200, which is an MLD wireless terminal, may connect to the base station 10 that is the AP that is closest to the wireless terminal 10 and has the highest RSSI, which does not support MLO. In this case, the wireless terminal 200, which is an MLD wireless terminal, and the base station 20, which is an MLD base station, cannot maximize the functionality (capabilities) of MLO.

[0023] 6(b), the base station 10 may not accommodate either the wireless terminal 100 or the wireless terminal 200, and both the wireless terminal 100 and the wireless terminal 200 may select the base station 20 as their destination depending on the distance to the AP and their wireless communication capability. In this case, the wireless terminal 100, the wireless terminal 200, and the base station 20 may not be able to maximize the MLO function (capability), and the entire network may not be optimized.

[0024] Next, a wireless communication system 1 according to an embodiment will be described. Fig. 1 is a diagram showing an example of the configuration of the wireless communication system 1 according to an embodiment.

[0025] As shown in FIG. 1, the wireless communication system 1 includes, for example, one or more MLD base stations 21, one or more base stations 11, and a control device (association determination device) 30.

[0026] Here, it is assumed that the base station 11 is a base station that does not support MLO and performs wireless communication using only radio waves in the 2 GHz band, and the wireless terminal 101 is a wireless terminal that does not support MLO and performs wireless communication using only radio waves in the 2 GHz band.

[0027] The MLD base station 21 is a base station that supports MLO and performs wireless communication using radio waves in the 2 GHz and 5 GHz bands, for example. The MLD wireless terminal 201 is a wireless terminal that supports MLO and performs wireless communication using radio waves in the 2 GHz and 5 GHz bands, for example.

[0028] Furthermore, when there is no distinction between base station 11 and MLD base station 21, the base station is referred to as an AP (Access Point), and when there is no distinction between wireless terminal 101 and MLD wireless terminal 201, the wireless terminal is referred to as an STA (Station).

[0029] The control device (association determination device) 30 controls each of the MLD base station 21 and the base station 11. For example, the control device 30 is connected to the network 400, collects specification information (capability information indicating wireless communication capabilities) and link operation information from the base station 11 and the MLD base station 21, and notifies the base station 11 and the MLD base station 21 of information indicating the AP to which the wireless terminal 101 and the MLD wireless terminal 201 should belong (association information).

[0030] 2 is a functional block diagram illustrating functions of the control device 30 according to one embodiment. As shown in FIG. 2, the control device 30 includes, for example, a communication unit 300, a collection unit 302, a tentative allocation unit 304, an estimation unit 306, a tentative reallocation unit 308, and a processing unit 310.

[0031] The communication unit 300 has a function of performing two-way communication with, for example, the base station 11 and the MLD base station 21. The communication unit 300 may also have a function of performing communication via the network 400.

[0032] The collection unit 302 collects capability information indicating the wireless communication capabilities (device specifications) of each of the MLD wireless terminal 201, MLD base station 21, wireless terminal 101, and base station 11 via the communication unit 300, and outputs the information to the estimation unit 306.

[0033] The capability information (specification information) of each AP and STA is the following information exchanged via a beacon, an association request, an association response, etc.

[0034] Capability information = {MLO support, maximum bandwidth, maximum number of streams, maximum number of aggregates, etc.}

[0035] For example, when STA-i belongs to AP-j, the maximum performance of STA-i is min (CAPABILITY OF STA-i, CAPABILITY OF AP-j). Note that since the specification information is immutable, once collected it does not need to be collected again.

[0036] The collection unit 302 may also collect link information (link operation information) indicating the connection status of each of the MLD wireless terminals 201 and 101 to the MLD base station 21 or base station 11 , and output the information to the estimation unit 306 .

[0037] The link information includes, for example, MCS (Modulation Coding Scheme) information estimated from the signal strength between each AP and STA, the number of STAs already accommodated by the AP, accommodated traffic information, traffic direction (upstream / downstream), traffic priority (high priority or low priority), the degree of airtime occupancy by other STAs on the link, and retransmission rate. Note that the link information changes depending on the operational status of the wireless communication system 1, and therefore needs to be collected periodically.

[0038] The provisional allocation unit 304 provisionally allocates an association destination to each of the MLD wireless terminals 201 and 101 via the communication unit 300, the MLD base station 21, and the base station 11 so that each of the MLD wireless terminals 201 and 101 can be accommodated by either the MLD base station 21 or the base station 11. The provisional allocation unit 304 then outputs the provisionally allocated association destination to the estimation unit 306.

[0039] The estimation unit 306 estimates the throughput of each of the MLD wireless terminal 201 and the wireless terminal 101 based on the capability information collected by the collection unit 302 and the destination provisionally assigned by the provisional assignment unit 304, and outputs the estimated throughputs to the reallocation unit 308.

[0040] The estimation unit 306 may also estimate the throughput of each of the MLD wireless terminals 201 and 101 based on link information indicating the connection status of each of the MLD wireless terminals 201 and 101 to the MLD base station 21 or base station 11.

[0041] The tentative reallocation unit 308 reallocates a destination to the MLD wireless terminal 201 or the wireless terminal 101 whose throughput estimated by the estimation unit 306 is less than a predetermined threshold. Then, the tentative reallocation unit 308 outputs the reallocated destination to the processing unit 310.

[0042] When the throughput of each of the MLD wireless terminals 201 and 101 satisfies a predetermined condition due to the assignment destination reallocated by the reallocation unit 308, the processing unit 310 performs processing to determine the assignment destination reallocated by the reallocation unit 308 as the final assignment destination, and outputs the processing result to the MLD base station 21 and base station 11 via the communication unit 300.

[0043] In this way, the control device 30 has a function of determining the AP to which each of the MLD wireless terminal 201 and the wireless terminal 101 will belong. More specifically, the control device 30 determines the AP to which each of the MLD wireless terminal 201 and the wireless terminal 101 will belong as follows (A) to (C) below.

[0044] (A) The control device 30 determines the destination of each of the MLD wireless terminals 201 and 101 so as to maximize the throughput of the STAs under each AP for which the destination is to be derived (maximizing the number of STAs that minimizes throughput). (B) The control device 30 determines the destination of each of the MLD wireless terminals 201 and 101 so as to maximize the throughput according to the wireless communication capabilities (optimizing so that a STA with two links can obtain a higher throughput than a STA with one link). (C) The control device 30 maximizes the throughput of a specific link (for example, determining the destination so as to maximize the throughput of a 5 GHz link).

[0045] Next, a description will be given of an example of operation of the wireless communication system 1. Fig. 3 is a flowchart showing an example of operation of the wireless communication system 1 according to an embodiment.

[0046] As shown in FIG. 3, in step 100 (S100), the control device 30 of the wireless communication system 1 collects capability information and link information of each AP and each STA.

[0047] In step 102 (S102), the control device 30 determines whether there is an STA with an undetermined destination, and if there is an STA with an undetermined destination (S102: Yes), proceeds to processing S104, and if there is no STA with an undetermined destination (S102: No), proceeds to processing S108.

[0048] In step 104 (S104), the control device 30 selects one STA whose destination has not yet been determined.

[0049] In step 106 (S106), the control device 30 provisionally assigns one AP from among all APs to which the selected STA can belong, and returns to the processing of S102.

[0050] In step 108 (S108), the control device 30 estimates the throughput of each STA. Specifically, the control device 30 estimates the throughput of each STA based on at least one of the capability information of the AP and each STA and the link information.

[0051] In step 110 (S110), the control device 30 selects, for example, one STA whose throughput is less than a predetermined threshold, and performs tentative re-allocation of an AP to that STA.

[0052] In step 112 (S112), the control device 30 determines whether or not there is a predetermined throughput improvement. If it determines that there is a throughput improvement (S112: Yes), it proceeds to processing of S116, and if it determines that there is no throughput improvement (S112: No), it proceeds to processing of S114.

[0053] For example, the control device 30 determines whether the throughput of STAs with a predetermined percentage of low throughput (bottom X% of STAs) among all STAs after the provisional reallocation has improved.

[0054] In step 114 (S114), the control device 30 returns the home destination of the STA to which the reallocation has been performed to the AP before the reallocation.

[0055] In step 116 (S116), the control device 30 determines whether the termination condition for the process to improve throughput has been met, and if it is determined that the condition has been met (S116: Yes), proceeds to processing of S118, and if it is determined that the condition has not been met (S116: No), return to processing of S110.

[0056] Here, the termination condition may be, for example, that the number of times the process is performed reaches a predetermined value, that the rate of improvement in throughput is below a threshold, or that the estimated throughput of all STAs reaches the maximum value of the capability of the device itself.

[0057] In step 118 (S118), the control device 30 determines the current destination of each STA, and notifies each STA of the determination result via the AP.

[0058] 4 is a graph illustrating the results of throughput improvement achieved by the wireless communication system 1 according to one embodiment. The graph shows the results when 10 wireless terminals capable of using two links and 10 wireless terminals capable of using only one link are mixed in an evaluation area of ​​100 (m) x 100 (m). The results of throughput improvement achieved by the wireless communication system 1 are indicated as "Proposed."

[0059] In this way, the wireless communication system 1 according to one embodiment can improve throughput in an environment where wireless terminals and base stations that support MLO and wireless terminals and base stations that do not support MLO are mixed, compared to when the STA is randomly assigned to an AP and compared to when the STA is assigned to the AP with the highest RSSI.

[0060] In addition, each function of the control device 30 may be configured, in part or in whole, by hardware such as a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array), or may be configured as a program executed by a processor such as a CPU.

[0061] For example, the control device 30 can be realized using a computer and a program, and the program can be recorded on a storage medium or provided via a network.

[0062] 5 is a diagram illustrating a hardware configuration of the control device 30 according to one embodiment. As shown in FIG. 5, the control device 30 has an input unit 50, an output unit 51, a communication unit 52, a CPU 53, a memory 54, and an HDD 55 connected via a bus 56, and functions as a computer. The control device 30 is also capable of inputting and outputting data to and from a computer-readable storage medium 57.

[0063] The input unit 50 is, for example, a keyboard and a mouse, etc. The output unit 51 is, for example, a display device such as a display.

[0064] The communication unit 52 corresponds to, for example, the above-mentioned communication unit 300, and is a communication interface that communicates with other devices.

[0065] The CPU 53 controls each component of the control device 30 and performs predetermined processing, etc. The memory 54 and HDD 55 store data, etc.

[0066] The storage medium 57 is capable of storing programs and the like that cause the control device 30 to execute the functions of the control device 30. Note that the architecture that configures the control device 30 is not limited to the example shown in FIG.

[0067] 1...wireless communication system, 11...base station, 21...MLD base station, 30...control device, 50...input unit, 51...output unit, 52...communication unit, 53...CPU, 54...memory, 55...HDD, 56...bus, 57...storage medium, 101...wireless terminal, 201...MLD wireless terminal, 300...communication unit, 302...collection unit, 304...temporary allocation unit, 306...estimation unit, 308...temporary reallocation unit, 310...processing unit, 400...network

Claims

1. A wireless communication system comprising: one or more MLD base stations capable of accommodating MLD wireless terminals that support MLO and wireless terminals that do not support MLO; one or more base stations capable of accommodating only wireless terminals that do not support MLO; and a control device that controls the MLD base stations and each of the base stations, wherein the control device comprises: a collection unit that collects capability information indicating wireless communication capabilities of the MLD wireless terminals, the MLD base stations, the wireless terminals, and each of the base stations; a provisional allocation unit that provisionally allocates an attribute to each of the MLD wireless terminals and each of the wireless terminals so that they are accommodated by either the MLD base station or the base station; an estimation unit that estimates the throughput of each of the MLD wireless terminals and each of the wireless terminals based on the capability information collected by the collection unit and the attribute provisionally allocated by the provisional allocation unit; and a reallocation unit that provisionally reallocates an attribute to the MLD wireless terminal or the wireless terminal whose throughput estimated by the estimation unit is less than a predetermined threshold. a processing unit that performs a process of determining the destination reallocated by the reallocated unit as a final destination when the throughput of the MLD wireless terminal and each of the wireless terminals satisfies a predetermined condition due to the destination reallocated by the reallocated unit.

2. The wireless communication system according to claim 1, characterized in that the estimation unit estimates the throughput of each of the MLD wireless terminal and the wireless terminal based on link information indicating a connection status of each of the MLD wireless terminal and the wireless terminal to the MLD base station or the base station.

3. A control device for controlling an MLD radio terminal that supports MLO, one or more MLD base stations capable of accommodating radio terminals that do not support MLO, and one or more base stations capable of accommodating only radio terminals that do not support MLO, comprising: a collection unit that collects capability information indicating radio communication capabilities of each of the MLD radio terminals, the MLD base station, the radio terminal, and the base station; a provisional allocation unit that provisionally allocates an attribute to each of the MLD radio terminals and the radio terminals so that they are accommodated by either the MLD base station or the base station; an estimation unit that estimates the throughput of each of the MLD radio terminals and the radio terminals based on the capability information collected by the collection unit and the attribute provisionally allocated by the provisional allocation unit; and a reallocation unit that provisionally reallocates an attribute to the MLD radio terminal or the radio terminal whose throughput estimated by the estimation unit is less than a predetermined threshold value, and a processing unit that performs a process of determining the destination reallocated by the reallocated unit as a final destination when the throughput of the MLD wireless terminal and each of the wireless terminals satisfies a predetermined condition due to the destination reallocated by the reallocated unit.

4. The control device according to claim 3, characterized in that the estimation unit estimates the throughput of each of the MLD wireless terminal and the wireless terminal based on link information indicating a connection status of each of the MLD wireless terminal and the wireless terminal to the MLD base station or the base station.

5. A wireless communication method in which a control device controls an MLD wireless terminal that supports MLO, one or more MLD base stations that can accommodate wireless terminals that do not support MLO, and one or more base stations that can accommodate only wireless terminals that do not support MLO, the method comprising: a collection step of collecting capability information indicating wireless communication capabilities of each of the MLD wireless terminals, the MLD base station, the wireless terminal, and the base station; a provisional allocation step of provisionally allocating an attribute to each of the MLD wireless terminals and the wireless terminals so that they are accommodated by either the MLD base station or the base station; an estimation step of estimating the throughput of each of the MLD wireless terminals and the wireless terminals based on the capability information collected by the collection step and the attribute provisionally assigned by the provisional allocation step; and a reallocation step of provisionally allocating an attribute to the MLD wireless terminal or the wireless terminal whose throughput estimated by the estimation step is less than a predetermined threshold, and a processing step of performing a process of determining the destination reallocated in the reallocation step as a final destination when the throughput of the MLD wireless terminal and each of the wireless terminals satisfies a predetermined condition due to the destination reallocated in the reallocation step.

6. The wireless communication method according to claim 5, wherein in the estimation step, the throughput of each of the MLD wireless terminal and the wireless terminal is estimated based on link information indicating a connection status of each of the MLD wireless terminal and the wireless terminal to the MLD base station or the base station.

7. A wireless communication program for causing a computer to function as each part of the control device according to claim 3 or 4.