Communication device, control method, and program thereof

Abstract

One of the objectives is to provide a mechanism for setting appropriate monitoring times when performing scans. [Solution] The communication device performs a first monitoring process to receive a notification signal transmitted by another communication device. If a destination AP (Access Point) is selected from one or more APs detected in the first monitoring process, a second monitoring process is performed. The monitoring time for which monitoring continues on one channel of the monitoring process is controlled. The first monitoring time in the first monitoring process is controlled to be shorter than the second monitoring time in the second monitoring process.

Description

Technical Field

[0001] The present invention relates to a communication device that performs wireless communication.

Background Art

[0002] As a communication standard for Wireless Local Area Network (Wireless LAN), the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard is known. In the IEEE 802.11 standard, regulations regarding communication using frequency bands such as the 2.4 GHz band, 5 GHz band, and 6 GHz band are defined.

[0003] Also, Patent Document 1 describes a mechanism that uses a set of specific non-unitary and non-continuous channels among 6 GHz channels as channels recommended for scanning. The search technique of Patent Document 1 makes it possible to shorten the scan time even in a wide band by intentionally narrowing the channels recommended for scanning.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] IEEE 802.11ax also introduced the concept of PSC, which treats a specific set of channels from among multiple channels in the 6GHz band as recommended channels for scanning, with the aim of reducing scan time. PSC stands for Preferred Scanning Channels. In PSC, a PSC is set every 80MHz, which is a channel recommended for scanning. However, there is a possibility that access point devices and other master devices may not start on the PSC channels, and in such cases, the station device needs to scan all channels to detect the opposing device. There are two types of scans: Active scan and Passive scan. In Active scan, the opposing device is detected by sending a Probe Request packet and receiving a Probe Response in response to it. In contrast, in Passive scan, the opposing device is detected by monitoring broadcast signals such as Beacons that the access point device and other master devices transmit at regular intervals. Since broadcast signals are transmitted at regular intervals, shortening the monitoring time for continuous monitoring processing per channel will shorten the overall scan time, but the probability of detecting the opposing device will decrease. Conversely, increasing the monitoring time per channel will lengthen the overall scan time, but it will increase the probability of detecting the opposing device. 6GHz scans are primarily passive scans, and since a large number of channels are specified in the 6GHz band, the setting of the monitoring time per channel can have a significant impact.

[0006] The present invention has been made in view of at least one of the above-mentioned problems. One aspect of the present invention is to provide a mechanism for setting an appropriate monitoring time when performing a scan. [Means for solving the problem]

[0007] A communication device as one aspect of the present invention includes: a first monitoring means that performs a first monitoring process for receiving a broadcast signal transmitted by another communication device; a second monitoring means that performs a second monitoring process when a destination AP (Access Point) is selected from one or more APs (Access Points) detected in the first monitoring process; and a control means that controls the monitoring time for which monitoring is continued in one channel of the monitoring process, wherein the control means controls the first monitoring time in the first monitoring process to be shorter than the second monitoring time in the second monitoring process. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to set an appropriate monitoring time when performing a scan. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example of a network configuration. [Figure 2] This figure shows an example of the hardware configuration of a communication device. [Figure 3] This figure shows an example of the functional configuration of a communication device. [Figure 4] This flowchart shows an example of the process by which the communication device according to the present invention determines the monitoring time. [Figure 5] This is a sequence diagram showing an example of the process by which the communication device in the present invention determines the monitoring time. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] <Communication System Configuration> Figure 1 shows the network configuration in which the communication device 102 (hereinafter referred to as STA102) according to this embodiment participates. STA102 is a station (STA) that has the role of participating in the network 100. Communication device 101 (hereinafter referred to as AP101) is an access point (AP) that has the role of constructing the wireless network 100. AP101 can communicate with STA102. That is, AP101 is an access point device (master unit / base station) that functions as an access point. Also, STA102 is a station device (slave unit / terminal) that functions as a station. In this embodiment, when it is not necessary to distinguish between AP101 and STA102, they may be collectively referred to as communication devices.

[0012] AP101 and STA102 can each perform wireless communication compliant with the IEEE 802.11ax / be / bn standard. IEEE stands for Institute of Electrical and Electronics Engineers. AP101 and STA102 can communicate in the 2.4 Hz, 5 GHz, and 6 GHz frequency bands. The frequency band used by each communication device is not limited to these, and different frequency bands, such as the 60 GHz band, may be used. Furthermore, AP101 and STA102 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz. The bandwidth used by each communication device is not limited to these, and different bandwidths, such as 240 MHz and 4 MHz, may be used.

[0013] Specific examples of AP101 include, but are not limited to, wireless LAN routers and personal computers (PCs). It may also be a software access point, a printing device that operates as a mobile access point, a digital still camera, a projector, etc. Similarly, specific examples of STA102 include, but are not limited to, digital still cameras, tablets, smartphones, PCs, mobile phones, video cameras, and headsets. Furthermore, STA102 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with the IEEE 802.11ax / be / bn standard. Each communication device can communicate using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, and 320MHz.

[0014] <Device configuration> Figure 2 shows an example of the hardware configuration of the communication devices (AP101 and STA102) in this embodiment. The communication device includes a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207. Note that there may be multiple antennas.

[0015] The memory unit 201 consists of one or more memories such as ROM and RAM, and non-volatile storage, and stores various information such as computer programs for performing various operations described later, and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. Non-volatile storage includes storage such as hard disks, non-volatile memory cards, and SSDs (Solid State Drives).

[0016] The control unit 202 is composed of, for example, one or more processors such as a CPU or MPU, and controls the entire AP101 by executing the computer program stored in the storage unit 201. Note that the control unit 202 may control the entire AP101 in cooperation with the computer program stored in the storage unit 201 and the OS (Operating System). Also, the control unit 202 generates data and signals (radio frames) to be transmitted in communication with other communication devices. Note that CPU is the abbreviation of Central Processing Unit, and MPU is the abbreviation of Micro Processing Unit. Also, the control unit 202 may include a plurality of processors such as multi-core processors, and control the entire communication device by the plurality of processors.

[0017] Also, the control unit 202 controls the functional unit 203 to execute predetermined processes such as wireless communication, imaging, printing, and projection. The functional unit 203 is hardware for the AP101 to execute predetermined processes.

[0018] The input unit 204 receives various operations from the user. The output unit 205 performs various outputs to the user via a monitor screen or a speaker. Here, the output by the output unit 205 may be display on the monitor screen, audio output by the speaker, vibration output, or the like. Note that both the input unit 204 and the output unit 205 may be realized by one module such as a touch panel. Also, the input unit 204 and the output unit 205 may be integrated with the communication device or may be separate bodies.

[0019] The communication unit 206 controls wireless communication compliant with the IEEE802.11ax / be / bn standard. In addition to the IEEE802.11ax / be / bn standard, the communication unit 206 may also control wireless communication compliant with other IEEE802.11 standard series or control wired communication such as wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. Note that the IEEE802.11 standard series includes standards such as IEEE802.11a / b / g / n / ac standards.

[0020] Note that when the communication device is compatible with NFC standards, Bluetooth standards, etc. in addition to the IEEE802.11ax / be / bn standard, it may control wireless communication compliant with these communication standards. Also, when the AP101 can execute wireless communication compliant with multiple communication standards, it may have a configuration with separate communication units and antennas corresponding to each communication standard. The communication device communicates data such as image data, document data, video data, etc. with other communication devices via the communication unit 206. Note that the antenna 207 may be configured separately from the communication unit 206 or may be configured as one module together with the communication unit 206.

[0021] The antenna 207 is an antenna capable of communication in the 2.4 GHz band, 5 GHz band, and 6 GHz band. In this embodiment, it is assumed that the communication device has one antenna, but it may have three antennas. Or it may have different antennas for each frequency band. Also, when the communication device has multiple antennas, it may have a communication unit 206 corresponding to each antenna.

[0022] Figure 3 shows a block diagram of the functional configuration of the communication device (AP101 and STA102) in this embodiment. Here, the communication device is assumed to include a wireless LAN control unit 301. Note that the number of wireless LAN control units is not limited to one; there may be two, three or more, etc. The communication device further includes a frame generation unit 302, a scan execution unit 303, a scan parameter setting unit 304, a monitoring time determination unit 305, and a UI control unit 306. These functional configurations can be realized, for example, by having a program stored in one or more memories constituting the storage unit 201 executed by one or more processors constituting the control unit 202. Note that some or all of these functional configurations may be implemented by dedicated hardware.

[0023] The wireless LAN control unit 301 comprises an antenna and circuit for sending and receiving wireless signals with other wireless LAN devices, and a program for controlling them. The wireless LAN control unit 301 performs wireless LAN communication control based on frames generated by the frame generation unit 302 in accordance with the IEEE 802.11 standard series.

[0024] The frame generation unit 302 generates a wireless control frame to be transmitted by the wireless LAN control unit 301. The frame generation unit 302 may also generate a Probe Request necessary for active scanning. The information of the generated frame is sent to the wireless LAN control unit 301 and transmitted to the communication partner.

[0025] The scan execution unit 303 performs a scan based on the information from the scan parameter setting unit 304 and the monitoring time determination unit 305. The scan execution unit 303 also determines whether the scan to be performed is an active scan or a passive scan and performs the necessary processing for each type of scan.

[0026] There are two types of scans: Active scans and Passive scans. In an Active scan, the scan unit 303 detects APs by sending Probe Request packets and receiving Probe Responses in response to them. In contrast, in a Passive scan, the scan unit 303 detects APs by monitoring broadcast signals such as Beacons that APs transmit at regular intervals.

[0027] The scan parameter setting unit 304 sets the parameters for performing a scan. These parameters could include, for example, the network identifier, such as the SSID or Short SSID. By setting the SSID during a scan, the system can search for APs with the same SSID when performing roaming. SSID stands for Service Set Identifier. Alternatively, the AP identifier, such as the BSSID (Basic Service Set Identifier), could be used. By setting the BSSID during a scan, the system can search for only specific APs. Other parameters could include frequency, encryption method, encryption key, and authentication method, but are not limited to these. By not setting any parameters, the system can search for all communication devices in the surrounding area.

[0028] The monitoring time determination unit 305 determines the monitoring time for monitoring AP broadcast signals during a passive scan, based on the parameters set by the scan parameter setting unit 304, in accordance with the operation of the flowchart explained in Figure 4. Here, AP broadcast signals can be, but are not limited to, Beacon frames, Probe Response frames, FILS Discovery frames, and Unsolisitid Probe Response frames transmitted by the AP. Furthermore, the monitoring time is the time allocated to receive broadcast signals transmitted by the AP on any one channel, and is the time during which monitoring is continued on one channel. In other words, the time for a passive scan is basically the monitoring time multiplied by the number of channels on which monitoring is performed.

[0029] The UI control unit 306 notifies the scan results of the scan execution unit 303, which are information about other communication devices, via the output unit 205. The UI control unit 306 also accepts parameter inputs to the scan parameter setting unit 304 via the input unit 204.

[0030] Next, we will explain scan control in STA102 using Figure 4. Figure 4 is a flowchart showing an example of the control performed by STA102, and is a flowchart that partially extracts the scan-related processing in order to explain the scan-related control. More specifically, the flowchart in Figure 4 shows a series of processes that start when STA102 changes the monitoring time of a passive scan by setting scan parameters.

[0031] Each process shown in the flowchart of Figure 4 is executed by the processor of the control unit 202 of the STA102 executing a computer program stored in the memory unit 201. Some processes, such as transmission and modulation, are implemented through the cooperation of the processor of the control unit 202 and various processors, ASICs, DSPs, FPGAs, etc., that constitute the communication unit 206. Display control and user operation reception control are implemented through the cooperation of the processor of the control unit 202 and the input unit 205 and output unit 205. When it is necessary to clearly indicate the main subject of a process, the functional unit described in Figure 3 will be used as the subject.

[0032] First, the STA102 receives a command to start the scan (S401). Then, it decides whether to perform a Passive Scan for the scan process to be performed (S402). The decision to perform a Passive Scan may be based on, but is not limited to, whether the frequencies covered are those that require Passive Scanning according to the radio wave regulations of each country, or the settings of the STA102 itself.

[0033] If it is determined not to perform a passive scan (S402 No), the process ends and the process necessary for an active scan begins. If it is determined to perform a passive scan (S402 Yes), it checks whether the scan parameters that meet the conditions for changing the monitoring time are set (S403). If the scan parameters that meet the conditions for changing the monitoring time are not set (S403 No), the monitoring time is set to the default, the process ends, and the process necessary for the scan begins (S404).

[0034] If a scan parameter matching the conditions for changing the monitoring time is set (Yes in S403), the monitoring time is set to a time equal to or greater than the AP's broadcast signal transmission interval (broadcast signal interval), the process ends, and the processing necessary for scanning begins (S405). In this embodiment, it is stated that S403 determines whether a scan parameter matching the conditions for changing the monitoring time is set, but this is not the only way. For example, it may be determined whether the user has selected a destination AP. In that case, if the user has selected a destination AP (Yes in S403), the process proceeds to S405. If the user has not selected a destination AP (No in S403), the process proceeds to S404. Note that a scan parameter matching the conditions for changing the monitoring time is, for example, a parameter that identifies an AP or network, and may also be a parameter that identifies a frequency band or channel. Specifically, this could be the SSID of the network that the AP is building, the BSSID of the AP, or the frequency on which the AP is building its network, but it is not limited to these. If a scan parameter that identifies an AP is set, it is assumed that the existence of the AP has already been confirmed, and the purpose is to connect to the network that the AP is building. In such cases, if the AP cannot be detected by scanning during the connection process, the user will be notified of a connection failure, making it crucial to detect the AP by scanning. Therefore, to improve the AP detection rate, it is necessary to set a monitoring time that is longer than the AP's notification signal transmission interval. The AP's notification signal transmission interval may be based on 100ms, which is used by many APs, or, if the information of a specific AP has been determined in advance through a scan process, the transmission interval of that AP's notification signal may be used as the basis. Alternatively, a predetermined reference value for the notification signal set by STA102 may be adopted.

[0035] Next, the operation of AP101 and STA102 in this embodiment will be explained using the sequence diagram shown in Figure 5. In Figure 5, AP101 has already established a network. STA102 receives a scan command from the user via the input unit 204 (F501). Here, it is assumed that no scan parameters are set in order to scan surrounding communication devices. Upon receiving the scan command, STA102 checks whether a passive scan is included in the scan to be performed (F502). In this embodiment, it is assumed that STA102 supports a 6GHz band channel and confirms that a passive scan will be performed. Subsequently, STA101 checks whether a scan parameter that changes the monitoring time is set in the scan command at F501 (F503). Here, no scan parameters are set at F501, so it confirms that no scan parameter that changes the monitoring time is set and sets the monitoring time to the default (F504). In this embodiment, the default monitoring time is 40ms. Also, in this embodiment, the transmission interval of the Beacon, which is the broadcast signal of AP101, is set to 100ms. Here, the 40ms monitoring time for STA101 occurs between the 100ms monitoring time for Beacon1 and Beacon2 of AP101, which can cause STA102 to fail to detect AP101 (F506). In F506, STA102 notifies the user of the scan results, which do not include AP101 (F507).

[0036] Upon receiving notification F507, the user issues another scan command F501 because the desired AP101 is not included in the scan results, and STA101 repeats processing F502 through F505 (F508). At this point, STA102 can detect AP101 because the Beacon4 of AP101 is transmitted during the 40ms scan monitoring time (F509). In this embodiment, the monitoring time for processing F509 is always 40ms, but this may be changed, for example, by extending the monitoring time according to the number of scan commands from the user within a certain period in which scan parameters have not been set.

[0037] STA102 notifies the user of the scan results including AP101 in F509 (F510). Upon receiving the notification in F510, the user, knowing that the desired AP101 is included in the scan results, sets the parameters to specify AP101 and issues a scan command to connect (F511). In F511, it is assumed that the SSID of AP101 is set, but the BSSID or frequency may also be set. In this embodiment, in order to explain the scan process of STA102, the scan is started in response to receiving a scan command from the user, but it is not limited to this. For example, the scan may be started based on a connection command to an AP specified by the user that requires a scan, or a command to perform other functions for connecting to an AP desired by the user.

[0038] Upon receiving a scan command, STA102 checks whether the scan to be performed includes a passive scan (F512). In this embodiment, STA102 is assumed to support 6GHz band channels and confirms that a passive scan will be performed. Subsequently, STA101 checks whether a scan parameter that changes the monitoring time is set in the scan command at F511 (F513). Here, since the SSID of AP101 is set in F511, it confirms that a scan parameter that changes the monitoring time is set and sets the monitoring time to be greater than or equal to the AP's broadcast signal interval (F514). In this embodiment, STA102 is set to 100ms, but for example, the broadcast signal interval of AP101 that was previously determined during a scan may be used, or the longest broadcast signal interval among the APs in the scan results may be used. Here, by setting the monitoring time of STA101 to 100ms or more, the 100ms broadcast signal interval of AP101 is covered, so the broadcast signal of AP101 can be received regardless of when the monitoring is performed. Here, AP101's Beacon6 can receive signals during the monitoring period, and STA102 can detect AP101 (F516).

[0039] As explained above, when a user requests a scan with parameters to identify an AP, the scan monitoring time should be set to be longer than the AP's notification signal transmission interval (e.g., 100ms). This improves the scan success rate and reduces the likelihood of notifying the user of connection failure. Furthermore, when a user requests a scan without parameters to identify an AP, shortening the monitoring time (e.g., less than 100ms) allows for a quicker response to the user with the scan results.

[0040] <Other Embodiments> In the above embodiment, user instructions are required when performing another scan after scanning surrounding communication devices, but this is not limited to this. For example, when a scan instruction is received by F501, the scan may be repeated until a connection instruction to the AP is received from the user. In that case, the monitoring time may be extended based on the fact that the scan has been repeated automatically. Alternatively, the monitoring time may be extended based on the fact that a predetermined amount of time has elapsed since the start of the scan.

[0041] Furthermore, in the above embodiment, the monitoring time is extended when scan parameters that match the conditions for changing the monitoring time are set, but this is not limited to this. The monitoring time may be shortened when scan parameters that match the conditions for changing the monitoring time are not set. In that case, the monitoring time when scan parameters that match the conditions for changing the monitoring time are not set may be set as the default. Also, when shortening the monitoring time in this way, the monitoring time may be changed according to the frequency band in which monitoring is performed. For example, the monitoring time for a 6GHz channel may be 40ms, the monitoring time for a 5GHz channel may be 50ms, and the monitoring time for a 2.4GHz channel may be 60ms. Alternatively, only the monitoring time for a 6GHz channel may be shortened.

[0042] Furthermore, the present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0043] Furthermore, the disclosure of the embodiments described above includes the following configuration.

[0044] (Composition 1) A communication device, A first monitoring means that performs a first monitoring process for receiving a notification signal transmitted by another communication device, A second monitoring means that executes a second monitoring process when a destination AP (Access Point) is selected from among the one or more APs (Access Points) detected in the first monitoring process, It includes control means for controlling the monitoring time for which monitoring continues in one channel of the monitoring process, The control means controls the first monitoring time in the first monitoring process to be shorter than the second monitoring time in the second monitoring process. A communication device characterized by the following features.

[0045] (Configuration 2) The system further includes a receiving means for receiving instructions from a user to select a destination AP from among the one or more APs detected in the first monitoring process. A communication device according to configuration 1, characterized by the features described above.

[0046] (Composition 3) The system further includes a display control means for displaying one or more APs detected in the first monitoring process. A communication device according to configuration 1 or configuration 2, characterized by the above.

[0047] (Composition 4) The selection of the AP to connect to means that one or more of the following are set: the SSID, Short SSID, BSSID, or frequency of the network established by the AP. A communication device according to any one of configurations 1 to 3, characterized in that...

[0048] (Composition 5) The aforementioned monitoring process refers to a passive scan, which is a process for receiving the broadcast signal transmitted by the AP. A communication device according to any one of configurations 1 to 4, characterized in that...

[0049] (Composition 6) The aforementioned notification signal is a Beacon frame, or a Probe Response frame, or a FILS Discovery frame, or an Unsolisitid Probe Response frame. A communication device according to any one of configurations 1 to 5, characterized by the above.

[0050] (Composition 7) The second monitoring time is 100ms or more. A communication device according to any one of configurations 1 to 6, characterized in that...

[0051] (Composition 8) In the first monitoring process, when monitoring channels in a first frequency band and channels in a second frequency band, the control means controls the monitoring time for the channels in the first frequency band to be shorter than the monitoring time for the channels in the second frequency band. A communication device according to any one of configurations 1 to 7, characterized by the above.

[0052] (Composition 9) The first frequency band is the 6GHz band. A communication device according to configuration 8, characterized by the above. [Explanation of symbols]

[0053] 100 Networks 101 AP 102 STA 201 Storage section 202 Control Unit 203 Functional Section 204 Input section 205 Output section 206 Communications Department 207 Antenna

Claims

1. A communication device, A first monitoring means that performs a first monitoring process for receiving a notification signal transmitted by another communication device, A second monitoring means that executes a second monitoring process when a destination AP (Access Point) is selected from one or more APs (Access Points) detected in the first monitoring process, It includes control means for controlling the monitoring time for which monitoring continues in one channel of the monitoring process, The control means controls the first monitoring time in the first monitoring process to be shorter than the second monitoring time in the second monitoring process. A communication device characterized by the following features.

2. The system further includes a receiving means for receiving instructions from a user to select a destination AP from among the one or more APs detected in the first monitoring process. The communication device according to feature 1.

3. The system further includes a display control means for displaying one or more APs detected in the first monitoring process. The communication device according to feature 1.

4. The selection of the AP to connect to means that one or more of the following are set for the network established by the AP: SSID, Short SSID, BSSID, or frequency. The communication device according to feature 1.

5. The aforementioned monitoring process refers to a Passive scan, which is a process for receiving the notification signal transmitted by the AP. The communication device according to feature 1.

6. The aforementioned notification signal is a Beacon frame, or a Probe Response frame, or a FILS Discovery frame, or an Unsolvized Probe Response frame. A communication device according to any one of claims 1 to 5, characterized by the features described herein.

7. The second monitoring time is 100 ms or more. The communication device according to feature 6.

8. In the first monitoring process, when monitoring channels in a first frequency band and channels in a second frequency band, the control means controls the monitoring time for the channels in the first frequency band to be shorter than the monitoring time for the channels in the second frequency band. The communication device according to feature 6.

9. The first frequency band is the 6 GHz band. The communication device according to feature 8.

10. A method for controlling a communication device, A first monitoring step which performs a first monitoring process for receiving a notification signal transmitted by another communication device, A second monitoring step is performed in which, if a destination AP (Access Point) is selected from one or more APs (Access Points) detected in the first monitoring process, a second monitoring process is executed. The monitoring process includes a control step that controls the monitoring time for which monitoring continues in one channel of the monitoring process, The control step controls the first monitoring time in the first monitoring process to be shorter than the second monitoring time in the second monitoring process. A method for controlling a communication device, characterized by the features described above.

11. A program for causing a computer to execute the control method of the communication device described in claim 10.

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