JP2005142893A - Selection method of access point and radio communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio access point selection method which can select an AP suitable for needs of an STA user. <P>SOLUTION: The STA acquires ESSID information set in the AP, used channel information, presence/absence information of encryption and communication speed information to support by receiving a beacon signal transmitted from the AP by the STA and in addition, radio interference between APs is analogized based on the used channel information. In addition, a signal level and a noise level of a used channel is measured in the case of receiving a Probe Response signal by transmitting a Probe Request signal and the signal level and the noise level are displayed in an order of priority items preliminarily registered in the STA. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a method for selecting an access point in a wireless communication apparatus communicating with an access point, and the wireless communication apparatus.

  In the wireless LAN system in Japan, the frequency band to be used is determined, and in the case of IEEE 802.11b which is one of the wireless LAN systems, 2.400 [GHz] to 2.497 [GHz] is used. The center frequency of the channel used for communication is from the first channel to the 14th channel (the 14th channel is 2.484 [GHz]) from 2.412 [GHz] to every 5 [MHz]. A frequency of 22 [MHz] consisting of 11 [MHz] before and after the center frequency is used.

  FIG. 4 is a schematic diagram showing use frequencies of three APs (wireless access points) set so as not to cause radio wave interference.

  Each center frequency is 1, 6, and 11 GHz, and it turns out that it communicates in a wide frequency range.

  FIG. 5 is a schematic diagram showing use frequencies of five APs set without considering radio wave interference.

  Each center frequency is 1, 5, 6, 9, 11 GHz, and arcs indicating the use frequency of one AP are overlapped. However, setting of the use frequency of the AP is left to an AP installation (administrator). ing.

  By the way, in the wireless LAN system, in an infrastructure mode in which wireless communication is performed between an AP (wireless access point) and an STA (wireless station), a plurality of APs may exist in the wireless area of the STA.

  FIG. 1 shows that in a wireless LAN system, a plurality of APs exist in a wireless area of a STA in an infrastructure mode in which wireless communication is performed between an AP (wireless access point) and a STA (wireless station) 10. It is a figure which shows a state.

  According to FIG. 1, the STA 10 and the APs 21 to 25 exist in the wireless area 30 of the STA 10. In order to perform wireless communication, the STA 10 needs to select an AP to be connected by some method and set the same ESSID as that AP in the STA 10. Note that “ESSID” is an Extended Service Set IDentifier, which is one of network identifiers in a wireless LAN, and is a network name given to avoid interference, and can be up to 32 alphanumeric characters. Can be set arbitrarily.

  As an AP selection method, a method is used in which the STA user inputs the same ESSID as the AP that the user wants to select. When using this method, the STA user needs to know the ESSID set in the AP to be selected.

  Also, since the AP is sending the ESSID with a beacon signal, the STA receives the beacon signal, acquires the ESSID of the desired AP, and sets the ESSID acquired by the operation of the STA user to the STA, or A method of automatically setting the STA is also used.

  Also, there is known a terminal that selects a base station having an optimal communication condition from a plurality of base stations when a base station reconnection instruction is input (see, for example, Patent Document 1). The merit is to improve communication quality without relying on handover.

The present invention obtains various information such as radio quality, used CH, ID, etc. when establishing a radio link with an access point (not a user's instruction), compares it with preset judgment conditions, and displays a selection list This is the selection method.
JP 2000-023226 A

  According to the above conventional example, the STA user cannot obtain information such as the communication speed and the channel used by the AP, and the state of radio wave interference between APs, the actual signal level and noise level. There is a problem that information cannot be obtained.

  Further, since the STA user leaves the radio wave interference between the APs to the AP installation (management) person, there is a possibility that the STA user is wirelessly connected to the AP having the poor radio wave interference.

  Therefore, there is a problem that the AP that meets the needs of the STA user is not necessarily connected wirelessly.

An object of the present invention is to make it possible to select an access point that meets the needs of a user of a wireless communication apparatus.

  The present invention displays information on an access point to which a wireless communication apparatus is connected in accordance with a signal from the access point and a pre-registered priority item among a plurality of items related to communication with the access point. To do.

  For example, by receiving a beacon signal from an access point, ESSID information, used channel information, encryption presence / absence information, supported communication speed information set in the access point are obtained, and based on the used channel information. To determine the radio wave interference status between the access points.

Further, the signal level and the noise level are measured based on the response signal from the access point to the signal from the wireless communication apparatus, and are displayed in the order of priority items registered in advance.

According to the present invention, it is possible to select an access point that meets a user's needs.

  The best mode for carrying out the invention is the following embodiment.

  As shown in FIG. 1, an example of an AP selection method in consideration of the number of APs in which radio wave interference is estimated in a wireless LAN system compliant with IEEE 802.11b will be described.

  The STA (wireless station) 10 can connect a digital camera and use an input / output unit and a display unit of the digital camera through the interface processing unit 13.

  FIG. 1 is a diagram illustrating a state in which a STA 10 and five APs (access points) 21 to 25 exist in the wireless area 30 of the STA 10.

  FIG. 2 is a block diagram showing the STA (wireless station) 10 in the above embodiment.

  The STA 10 includes a wireless transmission / reception unit 11, a storage unit 12, an interface processing unit 13, a timing unit 14, and a control unit 15.

  Before connecting the STA 10 to the AP, the connected AP information is registered in the STA 10. For registration, the connection AP information is registered in the STA 10 by using the liquid crystal screen of the digital camera connected to the STA 10 and the input key of the digital camera.

  FIG. 3 is a diagram showing a registration screen for registering permitted communication speeds and priority items in the embodiment.

  The control unit 15 of the STA 10 displays the registration screen illustrated in FIG. 3 on the liquid crystal screen of the digital camera, and prompts the user to input “permitted communication speed 41” and “priority item 42” into the check boxes. .

  The user designates the communication speed permitted by the AP in the “permitted communication speed 41” field. In the “priority item 42” field, it is possible to specify which point the user attaches importance to. A plurality of “permitted communication speeds 41” can be checked.

  In the example illustrated in FIG. 3, the “permitted communication speed 41” is checked at 5.5 Mbps and 11 Mbps, and the “priority item 42” is the number of interference APs (AP interference degree).

  Next, an operation for selecting an AP in the above embodiment will be described.

  11 and 12 are flowcharts showing an operation of selecting an AP in the above embodiment.

  First, the operation mode of the digital camera is confirmed (S1), and if it is not the shooting mode or the other communication mode, the STA 10 does not shift to the AP selection process until the operation mode becomes the communication mode. If the operation mode of the digital camera is the communication mode, the STA 10 displays a “communication setting” message on the display unit of the digital camera via the interface processing unit 13 (S2), and the time measuring unit 14 sets the measurement timer. Start (S3). The start of the measurement timer is used for the purpose of stopping reception when information collection to be performed next is not successful. When the measurement timer is started, AP search and wireless state measurement are started (S4).

  When the STA 10 receives the beacon signal transmitted from the APs 21 to 25 in its own wireless area 30 (S21 to S25), the control unit 15 of the STA 10 supports the ESSID, the used channel, and the support from the received beacon signal. The communication speed to be used and the presence / absence of encryption (WEP) are discriminated, and a database as shown in FIG. However, at this time, the received electric field level / noise level 603 and the number of interference APs 605 are blank.

  Next, the STA 10 transmits a Probe Request to each of the AP 21 to AP 25 in its own wireless area 30 (S26, S28, S30, S32, S34). At this time, the STA 10 sets the ESSID acquired by the beacon signal according to each AP.

  The probe response signal which is the response signal is acquired (S27, S29, S31, S33, S35). When acquiring the probe response signal, which is a response signal, the STA 10 measures the signal level and noise level of the channel used by each AP, and stores these information in the storage unit 12 of FIG. Stored in the field of received electric field level / noise level 603 in the database. Each item acquired by receiving the beacon signal and stored in the storage unit 12 is also included in the Probe Response signal, and may be compared with the storage unit 12 here.

  Since the database shown in FIG. 10 has been acquired by receiving the beacon signal and the probe response signal (S5), the measurement timer is stopped (S10). The STA 10 displays a message indicating “AP table editing in progress” on the display unit of the digital camera via the interface processing unit 13 (S11), and performs the following processing.

  If the measurement timer expires before the database can be acquired (S6), the STA 10 displays an “out of service” message on the display unit of the digital camera via the interface processing unit 13 (S7). This indicates that there is no AP that is the partner of the wireless communication. When a predetermined period of time has elapsed (S9), an out-of-service timer is started in order to control the AP search process to be executed again (S8).

  The STA 10 that has acquired the database executes processing for estimating the number of interfering APs based on the channel information of the database stored in the storage unit 12.

  In the IEEE802.11b system, the center frequency of the channel used for communication is set from 2.412 [GHz] to every 5 [MHz], and communication includes 11 [MHz] before and after the center frequency. A frequency of 22 [MHz] is used. That is, there is a possibility that radio interference occurs in each of the two channels before and after the used channel.

  If the use center frequencies of the five APs are 1, 5, 6, 9, and 11 as shown in the database of FIG. 6, the frequencies are used as shown in FIG. In FIG. 5, when the arcs overlap, radio wave interference has occurred. For example, since the AP that has radio interference with the AP having the center frequency of 1 (CH) is only the AP having the center frequency of 5 (CH), the interference AP is 1, and is stored in the column of the number of interference APs 605 in the database. Is done. As a result of examining interference for each AP, a database shown in FIG. 6 is obtained.

  Next, database editing (S12) will be described.

  The AP database shown in FIG. 6 is compared with the STA user registration shown in FIG. First, an applicable communication speed 604 smaller than 5.5 Mbps is removed from the database. Next, since the AP interference degree is set in the priority item 42, the AP interference degree is set in ascending order (radio wave interference). In the order in which communication is possible). When such an operation is performed, the database shown in FIG. 7 is obtained.

  The STA 10 displays the information of the edited database (FIG. 7) on the display unit of the digital camera via the interface processing unit 13 (S13). The user of the digital camera confirming this display operates the cursor with the input means of the digital camera and determines the AP to be connected.

  Here, the STA 10 user knows that the AP having the ESSID of AP1 has little interference but is encrypted by WEP. However, since the user of STA10 does not know the WEP key of AP1, it is assumed that he / she decides to connect to the AP having the ESSID of the second AP3 in FIG.

  The STA 10 sets its own ESSID to “AP3” and sends a probe request (S37). The AP having the ESSID “AP3” responds with a Probe Response signal (S38). Thereafter, an authentication & association process can be performed with the AP, and a wireless communication link can be established.

  The AP selection method is considered to be effective even for STAs having a display unit and an input unit therein.

  Further, in the above AP selection method, the number of interfering APs is estimated and stored in the database. However, as shown in FIGS. 4 and 5, as the distance from the center frequency increases, the transmission output becomes weaker. Then, as shown in FIG. 8, points may be given and stored in the interference AP column of the database.

  In FIG. 8, the point given to the center channel for each AP is set to 3, the adjacent channel is given points that decrease in order from 2, and the target AP adds the maximum value for each AP of the channel where the point exists to add interference. Points can be awarded. For example, AP2 points exist in 3-7 channels.

  In AP2, interference with AP1 occurs only in 3 channels, and the maximum point is 1 in 3 channels. Interference with AP3 occurs in 4-7 channels, and the maximum point is 3 in 6 channels. Interference with AP4 occurs in only 7 channels, and the maximum point is 1 in 7 channels. Interference with AP5 has not occurred. Therefore, the sum of the maximum points is 1 + 3 + 1 + 0 = 5.

  When the database is created as described above, it can be used in place of the database of FIG. 6 described above as shown in FIG.

  In addition, the addition of interference points may not exceed the point of the target AP when the maximum value for each AP of the channel in which the point exists is added in the target AP. For example, the point of AP2 exists in 3-7 channels. Interference with AP1 occurs in only 3 channels, and the maximum point is 1 in 3 channels.

  Interference with AP3 occurs in 4-7 channels, and the maximum point is 2 in 5-6 channels under conditions that do not exceed AP2 for each channel. Interference with AP4 occurs in only 7 channels, and the maximum point is 1 in 7 channels. Interference with AP5 has not occurred. Therefore, the sum of the maximum points is 1 + 2 + 1 + 0 = 4.

  When the database is created as described above, it becomes as shown in FIG.

  According to the above embodiment, when the STA receives the beacon signal transmitted from the AP, the ESSID information, the used channel information, the presence / absence information of encryption, and the supported communication speed information are set in the STA. The radio wave interference between APs is estimated from the acquired channel information.

Furthermore, according to the above-described embodiment, by transmitting a Probe Request signal, the Probe Response signal is received, and at that time, the signal level and noise level of the channel used are measured, and in order of priority items registered in advance in the STA. By displaying, it is possible to allow the user to select an AP that meets the needs.

The figure which shows the state in which several AP exists in the radio | wireless area of STA in the infrastructure mode which performs radio | wireless communication between AP (wireless access point) and STA (wireless station) 10 in a wireless LAN system. It is. It is a block diagram which shows STA (wireless station) 10 in the said Example. In the said Example, it is a figure which shows the registration screen which registers the communication speed to permit and a priority item. It is a schematic diagram which shows the utilization frequency of three AP (radio | wireless access point) set so that radio wave interference may not occur. It is a schematic diagram which shows the utilization frequency of five AP set without considering the radio wave interference. It is a figure which shows the example of the database which shows the result of having investigated interference about each AP. The AP database shown in FIG. 6 is compared with the STA user registration shown in FIG. 3, and the applicable communication speed 604 smaller than 5.5 is removed from the database, and the AP interference degree is low (radio wave interference). The database is rearranged in the order in which communication is possible. It is an example of the database in an Example. It is an example of the database in an Example. It is a figure which shows the example of the database in the said Example. It is a flowchart which shows the operation | movement which selects AP in the said Example. It is a flowchart which shows the operation | movement which selects AP in the said Example.

Explanation of symbols

10 ... STA (wireless station),
11 ... wireless transmission / reception unit,
12 ... storage unit,
13 ... interface processing unit,
14 ... Timekeeping department,
15 ... control unit,
21-25 ... AP (access point).

Claims (7)

In a method for selecting an access point in a wireless communication apparatus that communicates with an access point,
A registration step of pre-registering priority items among a plurality of items related to communication with an access point;
A receiving step of receiving a signal from the access point;
A control step for controlling to display the access point information corresponding to the signal received in the reception step and the priority item registered in the registration step;
A method of selecting an access point, characterized by comprising: In claim 1,
The control step includes controlling the access point to display a list of access points. In claim 1,
A determination step of determining channels used by a plurality of access points based on the signals received in the reception step;
Based on the determination in the determination step, a determination step of determining an interference situation regarding each access point;
Have
In the control step, the access point selection method is characterized in that control is performed so as to display access point information according to the determination result in the determination step and the priority item registered in the registration step. In claim 1,
Based on the signal received in the reception step, has a measurement step of measuring the signal level or noise level,
In the control step, the access point selection method is characterized in that control is performed so as to display access point information according to the measurement result in the measurement step and the priority item registered in the registration step. In claim 1,
A determination step of determining at least one of a channel used by the access point, a signal level, a noise level, a communication speed, an interference state between access points, and an encryption communication state based on the signal reception in the reception step; ,
In the registration step, any one of a signal level, a noise level, a communication speed, and an interference state between access points can be registered as a priority item. In claim 1,
The wireless communication device is connected to another device, and in the control step, the access point information is controlled to be displayed on the other device. In wireless communication equipment that communicates with access points,
Registration means for pre-registering priority items among a plurality of items related to communication with an access point;
Receiving means for receiving a signal from the access point;
Control means for controlling to display the signal received by the receiving means and the access point information corresponding to the priority item registered by the registration means;
A wireless communication apparatus comprising:

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