WO2018230868A1

WO2018230868A1 - Method for selecting operating frequency of wireless lan access device and apparatus therefor

Info

Publication number: WO2018230868A1
Application number: PCT/KR2018/006191
Authority: WO
Inventors: 강현수
Original assignee: 주식회사 케이티
Priority date: 2017-06-13
Filing date: 2018-05-31
Publication date: 2018-12-20
Also published as: KR20180135544A; KR102038691B1

Abstract

The present invention relates to a method for selecting an operating frequency band by a dual band AP in a wireless LAN system, the method comprising the steps of: collecting cell information from one or more APs existing in the wireless LAN system; analyzing a wireless environment of the wireless LAN system by using the collected cell information; and determining an operating frequency band of at least one of the APs on the basis of the analyzed wireless environment.

Description

Method and apparatus for selecting an operating frequency of a wireless LAN access device

The present invention relates to a method and apparatus for selecting an operating frequency of a wireless LAN access device. More specifically, the present invention relates to a method and an apparatus for adaptively selecting an operating frequency band suitable for a wireless environment among a plurality of frequency bands in a wireless LAN system supporting a plurality of frequency bands with the same antenna and a communication modem.

The frequency band currently used by the Wireless LAN System can be divided into the 2.4GHz band and the 5GHz band. In the 2.4 GHz band, WLANs are exposed to interference caused by other devices (eg, Bluetooth devices, RFID devices, microwave ovens, etc.) using the same radio frequency band and interference on the same system due to lack of non-overlapping channel resources. Therefore, it is more difficult to secure cell capacity than the WLAN environment of the 5GHz band. On the other hand, the wireless LAN of the 5 GHz band has a relatively large number of non-overlapping channel resources compared to the 2.4 GHz band, so that there is less interference between adjacent channels and a wider frequency band can be utilized.

In general, the WLAN system is advantageous to use the 5GHz frequency band in terms of terminal speed or cell capacity. However, there is a single band wireless LAN terminal supporting only the 2.4 GHz band, and due to the characteristics of the frequency band lower than the 5 GHz frequency band, the frequency of the 2.4 GHz band still has a great utility value in terms of cell coverage. Accordingly, a dual band access point (AP) that supports both the 2.4 GHz frequency band and the 5 GHz frequency band has been developed.

For example, as shown in FIG. 1, the conventional dual band AP 100 filters the frequency of the first antenna 110 and the 2.4 GHz band, which transmits / receives a wireless signal (ie, an RF signal) of the 2.4 GHz band. Band pass filter 120, the first communication modem 130 for modulating and demodulating the radio signal of the 2.4GHz band, the second antenna 140 for transmitting and receiving radio signals of the 5GHz band, filtering the frequency of the 5GHz band And a second communication modem 160 for modulating and demodulating a radio signal in a 5 GHz band.

However, despite the development of the dual band AP 100, there is a need (needs) to support a higher cell capacity in the same cell area, and the existing one 5GHz frequency band to meet the requirements There is a problem that can not be. Therefore, there is a need to develop a new type of dual band AP to secure cell capacity.

It is an object of the present invention to solve the above and other problems. Still another object is to provide a wireless LAN access device capable of selectively supporting a plurality of frequency bands using the same antenna and communication modem, and a wireless LAN system using the same.

Still another object is to provide a method and apparatus for detecting a wireless environment of a WLAN system and adaptively selecting an operating frequency of a dual band AP based on the detected wireless environment.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

According to an aspect of the present invention to achieve the above or another object, the method comprising: collecting cell information from one or more access points (APs) present in a wireless LAN system; Analyzing a wireless environment of the wireless LAN system using the collected cell information; And determining an operating frequency band of at least one of the APs based on the analyzed wireless environment.

In the present embodiment, the cell information collected from the APs may include information on the number of stations connected to the AP, received signal strength indicator (RSSI) information, noise information for each channel, channel utilization information, And information regarding single band stations. In addition, the APs present in the WLAN system may include dual band APs supporting a plurality of frequency bands with the same antenna and communication modem.

The analyzing of the radio environment in the operating frequency band selection method may further include determining whether among the stations connected to the AP, there is a station whose received power value (RSSI) falls below a predetermined threshold.

In addition, the step of analyzing the radio environment may further include checking whether there is an overloaded AP among the APs by using cell information of APs when there is a station having a reception power value below a threshold.

The wireless environment analysis step may further include checking whether there is an idle channel of a 5 GHz band usable by the overloaded AP when there is an overloaded AP.

The wireless environment analysis step may further include checking whether cell roaming of single band stations connected to the overloaded AP is possible when there is an idle channel of a 5 GHz band available in the overloaded AP. can do.

In the radio environment analysis step, when cell roaming of single band stations is possible, calculating an expected average yield of stations connected to an overloaded AP, and checking whether the calculated average yield exceeds a predetermined reference yield. It may further include.

The determining of the operating frequency band may include selecting one of the first and second operating frequency bands that can be provided to the same antenna in at least one of the APs.

According to another aspect of the invention, the AP information collecting unit for collecting cell information from one or more AP (Access Point) existing in the wireless LAN system; A wireless environment analyzer for analyzing a wireless environment of the wireless LAN system using the collected cell information; And an operating frequency selector configured to determine an operating frequency band of at least one of the APs based on the analyzed wireless environment.

In the present embodiment, the operating frequency band selection device may further include an AP controller for transmitting information on the operating frequency band determined by the operating frequency selection unit to the corresponding AP.

According to another aspect of the invention, the process of collecting cell information from one or more AP (Access Point) present in the wireless LAN system; Analyzing a wireless environment of the wireless LAN system using the collected cell information; And a computer readable recording medium storing a program for performing a process of determining at least one operating frequency band of the APs on a computer based on the analyzed wireless environment.

An operating frequency band selection method of a dual band AP and an effect thereof according to embodiments of the present invention will be described below.

According to at least one of the embodiments of the present invention, there is an advantage that a dual band AP supporting a plurality of operating frequencies may be provided by one antenna and a communication modem.

In addition, according to at least one of the embodiments of the present invention, there is an advantage in that an optimal operating frequency among a plurality of operating frequencies supported by the dual band AP may be automatically selected in consideration of the wireless situation of the WLAN system.

In addition, according to at least one of the embodiments of the present invention, by automatically changing the operating frequencies of the dual-band AP according to the surrounding wireless environment, there is an advantage that can support a higher cell capacity in the same cell area.

However, the operating frequency band selection method and the effect that the device can achieve according to the embodiments of the present invention is not limited to those mentioned above, other effects that are not mentioned in the following description It will be clearly understood by those skilled in the art.

1 is a block diagram of a conventional dual band AP;

2 is a schematic configuration diagram of a wireless LAN system according to an embodiment of the present invention;

3 is a schematic configuration diagram of a wireless LAN system according to another embodiment of the present invention;

4 is a block diagram illustrating a wireless LAN access device according to an embodiment of the present invention;

5 is a configuration block diagram of a master AP or an AP controller according to an embodiment of the present invention;

6 is a flowchart illustrating a method for selecting an operating frequency band according to an embodiment of the present invention.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same or similar components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other. In other words, the term 'part' used in the present invention refers to a hardware component such as software, FPGA or ASIC, and 'part' plays a role. But wealth is not limited to software or hardware. The 'unit' may be configured to be in an addressable storage medium or may be configured to play one or more processors. Thus, as an example, a 'part' may include components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, Subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays and variables. The functionality provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or further separated into additional components and 'parts'.

In addition, in describing the embodiments disclosed herein, when it is determined that the detailed description of the related known technology may obscure the gist of the embodiments disclosed herein, the detailed description thereof will be omitted. In addition, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, but are not limited to the technical spirit disclosed herein by the accompanying drawings, all changes included in the spirit and scope of the present invention. It should be understood to include equivalents and substitutes.

The present invention provides a method for adaptively selecting an operating frequency band suitable for a wireless environment among a plurality of frequency bands in a wireless LAN system including dual band APs supporting a plurality of frequency bands with the same antenna and a communication modem. Suggest a device.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic diagram of a wireless LAN system according to an embodiment of the present invention.

2, a wireless LAN system 200 according to an embodiment of the present invention may include a master AP 210 and at least one basic service set (hereinafter, referred to as a 'BSS'). Can be.

In the WLAN system 200, the master AP 210 may be connected to one or more stations (hereinafter, referred to as STAs) to configure a separate BSS (not shown). In this case, the master AP 210 may perform the operation of a general AP.

The master AP 210 may perform wired or wireless communication with the APs 230 present in each BSS 220. The master AP 210 monitors a wireless environment in the WLAN system 200 based on information received from each AP 230, and adaptively adjusts an operating frequency of a specific AP 230 based on the wireless environment. Determine (or select) the function.

In the present embodiment, the subject performing the operating frequency band selection algorithm is the master AP 210, and the AP 230 targeted for operating frequency selection is a dual band AP, and a plurality of frequency bands are provided by the same antenna and communication modem. It is a WiFi connection device to support. The plurality of frequency bands supported by the AP 230 may include an operating frequency of the 2.4 GHz band and an operating frequency of the 5 GHz band, but are not limited thereto.

The BSS 220 may include an access point 230, which controls a wireless network, and one or more stations 240 that are connected to and operate with the AP 230. . Here, the BSS 220 is a set of APs 230 and stations 240 capable of performing wireless communication while successfully synchronizing, and is not a concept indicating a specific area.

The AP 230 is a functional medium that provides access to a distributed system via a wireless medium for the stations 240 coupled to the corresponding BSS 220. In the BSS 220, the communication between the stations 240 is performed via the AP 230, but when the direct link is established, direct communication between the stations 240 may be performed. Can be.

The AP 230 may be referred to as a centralized controller, a base station (BS), a Node-B, a base transceiver system (BTS), or a site controller in addition to a name of an access point. The station 240 may include a terminal, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile terminal, or a mobile subscriber. Another name may be referred to as a mobile subscriber unit.

A distributed system (not shown) is a mechanism for one AP 230 to communicate with another AP 230. The distributed system (not shown) is not necessarily a network, and may be provided if it can provide a predetermined distributed service defined in IEEE 802.11. There is no limit to this. For example, the distributed system may be a wireless network such as a mesh network or a physical structure that connects the plurality of APs 230 to each other.

3 is a schematic diagram of a wireless LAN system according to another embodiment of the present invention.

Referring to FIG. 3, the WLAN system 300 according to another embodiment of the present invention may include an AP controller 310 and at least one basic service set (BSS) 320.

In the WLAN system 300, the AP controller 310 may be configured by separate independent hardware and / or software. Unlike the master AP 210 described above, the AP controller 310 does not configure a separate BSS and does not perform the function of a general AP.

The AP controller 310 may perform wired or wireless communication with the APs 330 present in the respective BSSs 320. The AP controller 310 monitors a wireless environment in the WLAN system 300 based on information received from each AP 330, and adaptively adjusts an operating frequency of a specific AP 330 based on the wireless environment. Determine (or select) the function.

In the present embodiment, the subject performing the operating frequency band selection algorithm is the AP controller 310, and the AP 330, which is the target of the operating frequency selection, is a dual band AP and uses a plurality of frequency bands with the same antenna and communication modem. It is a WiFi connection device to support. The plurality of frequency bands supported by the AP 330 may include an operating frequency of the 2.4 GHz band and an operating frequency of the 5 GHz band, but are not limited thereto.

Meanwhile, the BSS 320, the AP 330, and the station 340 illustrated in FIG. 3 are the same as or similar to the BSS 220, the AP 230, and the station 240 illustrated in FIG. 2. Detailed description thereof will be omitted.

4 is a block diagram illustrating a wireless LAN access device according to an embodiment of the present invention.

Referring to FIG. 4, the wireless LAN access device 400 according to the present invention includes a first communication modem 410, a second communication modem 420, a first filter 430, a second filter 440, and a third filter. The filter 450 may include a diplexer 460, a first antenna 470, a second antenna 480, and the like. The components shown in FIG. 4 are not essential to implementing the WLAN access point, so the WLAN access point described herein may have more or fewer components than those listed above.

The first communication modem 410 modulates and demodulates a radio signal in a first frequency band (eg, 2.4 GHz band) and a radio signal in a second frequency band (eg, 5 GHz band). can do.

The second communication modem 420 may perform an operation of modulating and demodulating a radio signal of a second frequency band (eg, 5 GHz band).

The first filter 430 may be disposed between the first communication modem 410 and the diplexer 460 to perform an operation of filtering only a radio signal of a first frequency band. The second filter 440 may be disposed between the first communication modem 410 and the diplexer 460 to perform an operation of filtering only a radio signal of a second frequency band. The third filter 450 may be disposed between the second communication modem 420 and the second antenna 480 to perform an operation of filtering only a radio signal of a second frequency band. Herein, the first to

third filters

430, 440, and 450 may be a band pass filter (BPF), but are not limited thereto.

The diplexer 460 is disposed between the first antenna 470 and the first and

second filters

430 and 440 so as to output two radio signals (RF signals) output from the two filters 430 and 440. ) May be transmitted to one antenna 470, and the two wireless signals received by the antenna 470 may be branched to two

filters

430 and 440.

That is, the diplexer 460 is a branch filter element used to send and receive two radio signals having different operating frequencies to one antenna, and a low pass filter through which a low frequency signal is generally passed. ) And a high pass filter (HPF) through which a high frequency signal passes.

The first antenna 470 may perform an operation of transmitting / receiving a radio signal of a first frequency band and a radio signal of a second frequency band. The second antenna 480 may perform an operation of transmitting / receiving a radio signal of a second frequency band.

As described above, the WLAN access point 400 is a dual band AP and is a WLAN access point capable of supporting two frequency bands with the same antenna 470 and communication modem 410. Therefore, the WLAN access point 400 may function in any one of two operation modes (that is, 2.4GHz / 5GHz operating mode and 5GHz / 5GHz operating mode) according to a wireless environment. In order to operate the dual band AP, there is a need for a method of recognizing a surrounding wireless situation and automatically selecting a frequency band to be used among the frequency bands of 2.4 GHz and 5 GHz.

5 is a block diagram illustrating a master AP or an AP controller according to an embodiment of the present invention.

Referring to FIG. 5, the master AP or the AP controller 500 according to the present invention uses the AP information collector 510, the wireless environment analyzer 520, the operating frequency selector 530, and the AP controller 540. It may include. The components shown in FIG. 5 are not essential to implementing a master AP or AP controller, so the master AP or AP controller described herein may have more or fewer components than those listed above. have.

The AP information collecting unit 510 may collect information of a plurality of APs existing in the

WLAN system

200 or 300. To this end, APs present in the corresponding

systems

200 and 300 may transmit information (hereinafter, referred to as 'cell information') regarding a cell managed by the AP to the master AP or the AP controller 500. The cell information may include information on the number of stations connected to each AP, RSSI (Received Signal Strength Indicator), noise per channel, channel utilization, information on single band stations, and the like. have.

The wireless environment analyzer 520 may monitor the surrounding wireless environment using cell information of APs collected through the AP information collector 510.

First, the wireless environment analyzer 520 determines whether there is a coverage hole by identifying whether there is a station whose received power value (RSSI) falls below a predetermined reference value (threshold value) of stations connected to each AP. Can be determined.

If the coverage hole does not occur, the wireless environment analyzer 520 may determine whether an overloaded AP exists among APs present in the

WLAN systems

200 and 300 based on the collected cell information of the APs. Here, the overloaded AP means an AP that does not provide a minimum yield for stations connected to the AP.

If the overloaded AP exists, the wireless environment analyzer 520 may determine whether there is a channel of 5GHz band that the AP can use. In this case, the wireless environment analyzer 520 may determine whether there is an idle channel of the 5 GHz band based on the channel state of the 5 GHz band used by adjacent APs of the overloaded AP.

If there is an idle channel of 5GHz band, the radio environment analyzer 520 determines whether cell roaming of 2.4GHz single band stations connected to the overloaded AP is possible based on the collected cell information of the APs. Can be.

If it is determined that the 2.4 GHz single band STAs are all accessible to the neighboring AP, the radio environment analyzer 520 switches the operating frequency in the overloaded AP to calculate the expected average yield when operating in the dual 5 GHz mode (5 GHz / 5 GHz mode). Can be calculated The wireless environment analyzer 520 may compare the calculated expected average yield with a predetermined reference yield mQoS.

The operating frequency selector 530 may determine the operating frequency of each AP based on the wireless environment recognized by the wireless environment analyzer 520.

The AP controller 540 may transmit information on an operating frequency band determined by the operating frequency selector 530 to the corresponding AP. The AP may maintain the current operating frequency band or change to another operating frequency band according to a command of the AP controller 540. Here, the AP to be selected as the operating frequency may be a dual band AP.

As such, the master AP or the AP controller 500 including the above-described components 510 to 540 may adaptively select operating frequency bands of the dual band APs based on the surrounding wireless environment.

6 is a flowchart illustrating a method for selecting an operating frequency band of an AP according to an embodiment of the present invention.

Referring to FIG. 6, the AP controller 500 may collect cell information of a plurality of APs present in the WLAN system 200 (S610). To this end, the APs present in the system 200 may provide information on the number of connected stations, RSSI (Received Signal Strength Indicator), noise per channel, channel utilization, and information on single band stations. Information may be transmitted to the AP controller 500. Here, the RSSI may include at least one of an uplink RSSI and a downlink RSSI. Similarly, the noise per channel may include at least one of uplink channel noise and downlink channel noise.

The AP controller 500 may monitor the surrounding wireless environment by using the information collected from the APs.

First, the AP controller 500 determines whether there is a coverage hole by identifying whether there is a station whose received power value (RSSI) falls below a predetermined reference value (threshold value) among stations connected to each AP. It can be confirmed (S620).

As a result of the checking in step 620, when a coverage hole occurs in the WLAN system (that is, when there is a station having an RSSI falling below a predetermined reference value), the AP controller 500 determines that the AP to which the station is connected. The operating frequency may be selected to the 2.4GHz band (S680).

For example, when a coverage hole occurs in a specific AP, when the operating frequency of the AP is changed from the 2.4 GHz frequency band to the 5 GHz frequency band, the stations connected to the AP have a narrow cell coverage due to the frequency characteristics. This results in lower RSSI. Therefore, when a coverage hole occurs in the 2.4 GHz / 5 GHz operating mode, the AP controller 500 preferably maintains the operating mode of the AP in the 2.4 GHz / 5 GHz operating mode. On the other hand, when a coverage hole occurs in the Dual 5G mode, the AP controller 500 preferably switches the operation mode of the AP from the Dual 5G mode to the 2.4G / 5G mode.

On the other hand, if the coverage hole does not occur in the wireless LAN system as a result of step 620 (that is, when there is no station having an RSSI falling below a predetermined reference value), the AP controller 500 may determine from APs. Based on the collected information, it may be checked whether an overloaded AP exists among APs present in the system 200 (S630).

In the present embodiment, the overloaded AP means an AP that does not provide the minimum yield for the stations connected to the AP. Therefore, the AP controller 500 may determine whether the overloaded AP exists by using Equation 1 below. That is, the AP controller 500 may determine the AP as an overloaded AP when the average yield of stations connected to a specific AP does not exceed a predetermined reference yield (mQoS).

here,

Is an equation for calculating an expected data rate of idle STAs in the i th AP,

Is the actual data rate of the Active STAs at the i th AP.

Is the number of STAs accessing the 2.4 GHz band from the i th AP,

Is the number of STAs accessing the 5 GHz band from the i th AP,

Is the number of Active STAs in the 2.4 GHz band at the i th AP,

Is the number of Active STAs in the 5 GHz band at the i th AP,

Channel Utilization in the 2.4 GHz band from the i th AP,

Channel Utilization in the 5 GHz band from the i th AP,

Is the 2.4 GHz band physical rate of the j th STA connected to the i th AP,

Is the 5 GHz band physical rate of the k th STA connected to the i th AP.

As a result of checking in step 630, when there is no overloaded AP, the AP controller 500 may select an operating frequency of the corresponding AP as a 2.4 GHz band (S680).

Meanwhile, as a result of checking in step 630, when there is an overloaded AP, the AP controller 500 may check whether there is an idle channel of a 5 GHz band available in the corresponding AP (S640). In fact, if no channel is available in the 5GHz band, no further processing is necessary.

The AP controller 500 may determine whether there is an idle channel in the 5 GHz band based on the channel state of the 5 GHz band used by adjacent APs of the overloaded AP. In this case, the AP controller 500 determines that an idle channel exists if a channel other than the channel of the 5 GHz band used by the neighboring APs exists, or if the interference amount from the channel is less than the reference value even if the channel is already occupied. can do.

As a result of checking in step 640, when there is no idle channel of the 5GHz band available in the overloaded AP, the AP controller 500 may select the operating frequency of the AP as the 2.4GHz band (S680).

Meanwhile, as a result of checking in step 640, when there is an idle channel of 5 GHz band available in the overloaded AP, the AP controller 500 is a 2.4 GHz single band station connected to the overloaded AP based on information collected from the APs. It is possible to check whether cell roaming is possible (S650). When the overloaded AP operates in Dual 5G mode, single band STAs supporting only 2.4 GHz can no longer access the overloaded AP.

The AP controller 500 may determine whether cell roaming of single band stations is possible using Equation 2 below. That is, when the single band STAs present in the overloaded AP move to the neighboring AP, the AP controller 500 includes a single band station when the estimated average yield that can be obtained from the neighboring AP exceeds the predetermined reference yield mQoS. It can be determined that cell roaming is possible. The target AP per single band STA may be determined to be the AP having the highest reception power value among neighboring APs.

here,

Is the number of single band STAs connected to the 2.4 GHz band at the i th AP,

Is the number of single-band STAs connected to the 2.4 GHz band at the j th AP, TA is the index set of target APs, c (TA) is the number of target APs,

Channel Utilization of the 2.4 GHz band from the j th AP,

Is the 2.4 GHz band physical rate of the k th STA connected to the j th AP.

As a result of checking in step 650, when at least one of the single band STAs present in the overloaded AP cannot access the neighboring AP, the AP controller 500 may select an operating frequency of the corresponding AP as the 2.4 GHz band (S680). .

On the other hand, as a result of the check in step 650, when all single-band STAs present in the overloaded AP can access the neighboring AP, the AP controller 500 is expected to operate in the dual 5GHz mode by switching the operating frequency in the overloaded AP The average yield can be calculated. The AP controller 500 may check whether the calculated expected average yield exceeds a predetermined reference yield mQoS (S660). This is to prevent the meaningless frequency switching when the overloaded AP is operated in Dual 5G mode in a situation where the performance of the STAs is not actually improved.

The AP controller 500 may determine whether to change the operating frequency of the overloaded AP using Equation 3 below.

here,

Is the number of STAs accessing the 2.4 GHz band from the i th AP,

Is the number of STAs accessing the 5 GHz band from the i th AP,

Is the number of single band STAs connected to the 2.4 GHz band at the i th AP,

Is the 5GHz band physical rate of the j th STA connected to the i th AP.

As a result of the checking in step 660, when the estimated average yield when operating in the dual 5 GHz mode in the overloaded AP does not exceed the predetermined reference yield (mQoS), the AP controller 500 sets the operating frequency of the corresponding AP to the 2.4 GHz band. Can be selected (S680).

Meanwhile, as a result of checking in step 660, when the estimated average yield when operating in the dual 5GHz mode in the overloaded AP exceeds the predetermined reference yield (mQoS), the AP controller 500 sets the operating frequency of the corresponding AP to 5GHz band. Can be selected (S670).

The AP controller 500 may repeatedly perform the operations of steps 610 to 680 described above until the operation frequency band selection algorithm is terminated (S690).

As described above, the AP controller according to the present invention may monitor the wireless situation in a wireless LAN system in real time and automatically change the operating frequency bands of the dual band APs based on the wireless situation. In addition, the AP controller can select an operating frequency band that can guarantee a minimum transmission speed to stations connected to the dual band AP.

Meanwhile, in the present exemplary embodiment, the operation of the operating frequency selection algorithm is illustrated in the AP controller, but is not limited thereto. It will be apparent to those skilled in the art that the same operating frequency selection algorithm may be performed in the master AP.

The present invention described above can be embodied as computer readable codes on a medium in which a program is recorded. The computer-readable medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable media include hard disk drives (HDDs), solid state disks (SSDs), silicon disk drives (SDDs), ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and the like. There is this. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Claims

Collecting cell information from one or more access points (APs) in the WLAN system;

Analyzing a wireless environment of the wireless LAN system using the collected cell information; And

Determining an operating frequency band of at least one of the APs based on the analyzed wireless environment.
The method of claim 1,

The cell information includes information on the number of stations connected to an AP, RSSI (Received Signal Strength Indicator) information, channel-specific noise information, channel utilization information, and information on single band stations. And at least one operating frequency band selection method.
The method of claim 1,

The AP for selecting the operating frequency band is an operating frequency band selection method, characterized in that the dual-band AP supporting a plurality of frequency bands with the same antenna and communication modem.
The method of claim 1, wherein the analyzing of the wireless environment comprises:

And checking whether there is a station whose received power value (RSSI) falls below a predetermined threshold among the stations connected to the APs.
The method of claim 4, wherein the analyzing of the wireless environment comprises:

If there is a station having a received power value less than or equal to the threshold, determining whether an overloaded AP exists among the APs by using the collected cell information.
The method of claim 5,

If the average yield of the stations connected to a particular AP does not exceed a predetermined reference yield, the AP is determined as an overloaded AP.
The method of claim 5, wherein the analyzing of the wireless environment comprises:

And if the overloaded AP exists, checking whether there is an idle channel of a 5 GHz band usable in the overloaded AP.
The method of claim 7, wherein the radio environment analysis step,

If there is an idle channel of a 5 GHz band usable in the overloaded AP, checking whether cell roaming of single band stations connected to the overloaded AP is possible; How to choose.
The method of claim 8,

And determining that cell roaming of the single band stations is possible when the expected average yield that can be obtained from the neighboring AP of the overloaded AP exceeds a predetermined reference yield.
The method of claim 8, wherein the radio environment analysis step,

If cell roaming of the single band stations is possible, calculating an expected average yield of the stations connected to the overloaded AP and confirming that the calculated expected average yield exceeds a predetermined reference yield. Operating frequency band selection method.
The method of claim 1, wherein the determining of the operating frequency band,

At least one of the APs selects one of the first and second operating frequency bands that can be provided to the same antenna.
An AP information collecting unit collecting cell information from one or more access points (APs) existing in the WLAN system;

A wireless environment analyzer for analyzing a wireless environment of the wireless LAN system using the collected cell information; And

And an operating frequency selector configured to determine an operating frequency band of at least one of the APs based on the analyzed wireless environment.
The method of claim 12,

And an AP controller configured to transmit information about an operating frequency band determined by the operating frequency selector to a corresponding AP.
The method of claim 12,

The AP as the selection target of the operating frequency band is an operating frequency band selection device, characterized in that the dual-band AP supporting a plurality of frequency bands with the same antenna and communication modem.
The method of claim 12,

The wireless environment analyzer, the operating frequency band selection device, characterized in that whether there is a station that the received power value (RSSI) falls below a predetermined threshold among the stations connected to the AP.
The method of claim 15,

The wireless environment analysis unit, if there is a station having a reception power value less than the threshold, using the collected cell information, the operating frequency band selection device, characterized in that whether there is an overloaded AP among the AP.
The method of claim 16,

The wireless environment analyzer, if there is an overloaded AP, the operating frequency band selection device, characterized in that whether there is an idle channel of the 5GHz band available in the overloaded AP.
The method of claim 17,

The radio environment analyzer, when there is an idle channel of the 5GHz band available in the overloaded AP, operating frequency characterized in that it is possible to determine whether cell roaming (cell Roaming) of the single-band stations connected to the overloaded AP Band selector.
The method of claim 18,

When the cell roaming of the single band stations is possible, the radio environment analyzer calculates an expected average yield of the stations connected to the overloaded AP, and checks whether the calculated average yield exceeds a predetermined reference yield. An operating frequency band selection device.
A computer-readable recording medium storing a program for causing a method according to any one of claims 1 to 11 to be performed on a computer.