Communication device, communication method, non-transitory computer-readable storage medium, and computer program product

Abstract

The invention provides a communication apparatus, a communication method, a non-transitory computer-readable storage medium, and a computer program product. The communication apparatus includes: an obtaining unit configured to obtain information of a plurality of access points of different frequency bands; a changing unit configured to compare a frequency band during the connection with a frequency band of a roaming object, and change a roaming condition for performing roaming; and an execution unit configured to execute roaming in a case where the signal of the frequency band during the connection satisfies the roaming condition.

Description

Technical Field

[0001] The present invention relates to a communication device, a communication method, a non-transitory computer-readable storage medium, and a computer program product. Background Art

[0002] Roaming is known for switching a communication device between access points (hereinafter referred to as APs) of the same SSID. For roaming, function activation conditions are set. For example, roaming is performed when one of the signal-to-noise ratio (hereinafter referred to as SNR) and the received signal strength indication (hereinafter referred to as RSSI) falls below a predetermined threshold. SNR is the ratio of signal to noise. If the signal-to-noise ratio is high, the influence of noise is small and the signal is strong, and if the signal-to-noise ratio is low, the influence of noise is large and the signal is weak. RSSI is an indication of the strength of the received signal. If the RSSI is high, the signal is strong, and if the RSSI is low, the signal is weak.

[0003] Japanese Patent Laid-Open No. 2014-232977 discloses a method of scanning the same band as that of a currently connected AP channel as a high-priority scan band, and scanning a band different from that of the currently connected channel when no roaming destination AP exists as a result of the scan.

[0004] Japanese Patent Laid-Open No. 2023-72130 discloses a method of reading out a roaming start condition that associates location information of a mobile unit, direction information indicating a direction in which the mobile unit enters a location indicated by the location information, and an RSSI threshold, and setting the RSSI threshold based on a detection value of the location information of the mobile unit and a detection value of the direction information of the mobile unit. Summary of the Invention

[0005] However, in the conventional technology disclosed in the above patent document, when the frequency band of the connecting AP and the frequency band of the roaming destination AP differ during roaming, the throughput after roaming may decrease as a result of roaming. This is generally because the throughput varies depending on the frequency band.

[0006] The present invention provides a technique for reducing the drop in throughput after roaming.

[0007] According to one aspect of the present disclosure, a communication device is provided, including: an obtaining unit configured to obtain information of a plurality of access points of different frequency bands; a changing unit configured to compare a frequency band during connection with a frequency band of a roaming target and change a roaming condition for performing roaming; and an executing unit configured to execute roaming if a signal of the frequency band during connection satisfies the roaming condition.

[0008] According to another aspect of the present disclosure, a communication method is provided, including: obtaining information of a plurality of access points of different frequency bands; comparing the frequency band during connection with the frequency band of a roaming object to change a roaming condition for performing roaming; and performing roaming if a signal of the frequency band during connection satisfies the roaming condition.

[0009] According to another aspect of the present disclosure, a non-transitory computer-readable storage medium is provided, storing a computer program that, when read and executed by a computer, causes the computer to function as: an obtaining unit configured to obtain information of a plurality of access points of different frequency bands; a changing unit configured to compare a frequency band during connection with a frequency band of a roaming target and change a roaming condition for performing roaming; and an executing unit configured to perform roaming if a signal of the frequency band during connection satisfies the roaming condition.

[0010] According to another aspect of the present disclosure, a computer program product is provided, comprising a computer program that, when read and executed by a computer, causes the computer to function as: an obtaining unit configured to obtain information on a plurality of access points of different frequency bands; a changing unit configured to compare a frequency band during connection with a frequency band of a roaming target and change a roaming condition for performing roaming; and an executing unit configured to perform roaming if a signal of the frequency band during connection satisfies the roaming condition.

[0011] Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A is a block diagram showing the hardware arrangement of the digital camera 100;

[0013] Figure 1B is a perspective front view of the digital camera 100;

[0014] Figure 1C is a perspective rear view of the digital camera 100;

[0015] Figure 2A This is a diagram of a settings screen for setting up communications;

[0016] Figure 2B This is a diagram of a selection screen for selecting a network;

[0017] Figure 2C FIG. 1 is a diagram showing a completion screen indicating completion of connection;

[0018] Figure 3 is a diagram showing a system configuration including a digital camera according to an embodiment;

[0019] Figure 4 is a sequence diagram showing processing between the digital camera and the AP according to the first embodiment;

[0020] Figure 5 is a flowchart showing the processing of the digital camera according to the first embodiment;

[0021] Figure 6 is a sequence diagram showing processing between a digital camera and an AP according to the second embodiment; and

[0022] Figure 7A and Figure 7B is a flowchart illustrating processing of the digital camera according to the second embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. While various features are described in the embodiments, this does not limit the invention to requiring all such features, and multiple such features may be appropriately combined. Furthermore, in the accompanying drawings, identical or similar structures are assigned identical reference numerals, and redundant descriptions thereof are omitted.

[0024] <Arrangement of Digital Camera>

[0025] First, refer to Figures 1A to 1C The arrangement and functions of the digital camera 100 according to the present embodiment will be described. Figures 1A to 1C : is a diagram showing the arrangement of a digital camera according to the present embodiment. More specifically, Figure 1A is a block diagram showing the hardware arrangement of the digital camera 100 . Figure 1B It is a perspective front view of the digital camera 100 . Figure 1C It is a perspective rear view of the digital camera 100 .

[0026] Note that in this embodiment, a digital camera capable of capturing video (hereinafter referred to as "images") such as still images or moving images will be described as an example of a communication device. However, the application of this embodiment is not limited to digital cameras. For example, the communication device may be an information processing device such as a tablet device or personal computer with a camera function, a surveillance camera, or a medical camera. The digital camera 100 includes a control unit 101, an imaging unit 102, a nonvolatile memory 103, a working memory 104, an operation unit 105, a display unit 106, a recording medium 107, and a connection unit 108.

[0027] The control unit 101 is an arithmetic processing device that comprehensively controls the entire digital camera 100. The control unit 101 implements various processes such as communication processing and control processing (to be described later) by executing a program stored in a non-volatile memory 103 (to be described later). The control unit 101 includes, for example, a central processing unit (CPU). Instead of or in addition to the CPU, the control unit 101 may include other processors such as a microprocessing unit (MPU), a graphics processing unit (GPU), and a quantum processing unit (QPU). Note that instead of the control unit 101 controlling the entire device, part or all of the device may be controlled by sharing processing between one or more hardware units such as an application-specific integrated circuit (ASIC) and a field-programmable gate array (FPGA).

[0028] Control unit 101 implements functions such as obtaining, changing, and executing by reading programs stored in nonvolatile memory 103. More specifically, control unit 101 obtains information about multiple access points (hereinafter referred to as APs) in different frequency bands via connection unit 108. Control unit 101 compares the connected frequency band with the roaming target frequency band and changes the roaming conditions for executing roaming. If the signal in the connected frequency band meets the roaming conditions, control unit 101 executes roaming. Further details of the processing performed by control unit 101 will be described later.

[0029] The imaging unit 102 includes a lens group including a zoom lens and a focus lens, as well as a shutter with an aperture function. The imaging unit 102 includes an image sensor composed of, for example, a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) element, which converts the subject image into an electrical signal, and an A / D converter that converts the analog image signal output from the image sensor into a digital signal. Under the control of the control unit 101, the imaging unit 102 converts the subject image light formed by the lens included in the imaging unit 102 into an electrical signal via the image sensor, performs noise reduction processing, and outputs image data generated from the digital signal. The image data output from the imaging unit 102 is recorded, for example, on the recording medium 107.

[0030] The nonvolatile memory 103 is an electrically erasable and recordable memory, and for example, an electrically erasable programmable read-only memory (EEPROM) or the like is used. Constants and programs used for the operation of the control unit 101 are recorded in the nonvolatile memory 103. The programs are programs for executing communication processing and control processing (to be described later) in this embodiment.

[0031] The working memory 104 temporarily stores programs and data. The working memory 104 is, for example, a random access memory (RAM). The working memory 104 is used as a work area for constants and variables used in the operation of the control unit 101, as well as programs read from the nonvolatile memory 103. The working memory 104 is also used as a buffer memory for temporarily storing image data captured by the imaging unit 102, and as image display memory for the display unit 106.

[0032] The operation unit 105 includes operation members such as various switches, buttons, and a touch panel for accepting various operations from the user. Figure 1B and Figure 1C As shown, the operation unit 105 includes, for example, a shutter button 105a, a playback button 105b, a four-way key 105c, and a touch panel 105d. The shutter button 105a accepts operations related to photographing a subject. The playback button 105b accepts operations related to replaying captured images. The four-way key 105c includes up, down, left, and right buttons and accepts operations related to various camera settings. The touch panel 105d is formed integrally with the display unit 106 and accepts various operations.

[0033] During operation, the shutter button 105a is held in a half-stroke position (instructing shooting preparation) and generates a first shutter release signal. Upon receiving the first shutter release signal, the control unit 101 controls the imaging unit 102 to initiate one of the following processes: autofocus (AF), automatic exposure (AE), automatic white balance (AWB), and flash pre-emission (EF). Upon completion of the operation, the shutter button 105a is held in a full-stroke position (instructing shooting) and generates a second shutter release signal. Upon receiving the second shutter release signal, the control unit 101 initiates a series of shooting processes, from reading signals from the imaging unit 102 to writing image data on the recording medium 107.

[0034] The display unit 106 displays a viewfinder image during shooting, displays captured images, and displays text used for interactive operations. The display unit 106 is, for example, a display device such as a liquid crystal display or an organic EL display. The display unit 106 may be integrated with the digital camera 100 or may be an external device connected to the digital camera 100. It is sufficient that the digital camera 100 is connectable to the display unit 106 and has a function for controlling the display of the display unit 106.

[0035] The recording medium 107 records the image data output from the imaging unit 102 as an image file. The control unit 101 reads out the image file recorded on the recording medium 107. The recording medium 107 may be a memory card or a hard disk drive attached to the digital camera 100, or a flash memory or a hard disk drive incorporated in the digital camera 100. It is sufficient for the digital camera 100 to have a component that accesses at least the recording medium 107.

[0036] The connection unit 108 is an interface for connecting to an external device in a communicative manner. The digital camera 100 according to this embodiment can exchange data with the external device via the connection unit 108. For example, the digital camera 100 transmits image data output from the imaging unit 102 to the external device via the connection unit 108. The digital camera 100 can also receive control commands output from the external device via the connection unit 108. Note that in this embodiment, the connection unit 108 includes an interface for communicating with the external device via a wireless LAN in accordance with the IEEE 802.11 standard. The control unit 101 controls the connection unit 108 to achieve wireless communication with the external device.

[0037] <Display Screen of Digital Camera>

[0038] Next, refer to Figures 2A to 2C A display screen of the digital camera 100 according to the present embodiment will be described. Figures 2A to 2C Shown is a display screen of a digital camera. Figure 2A This is a diagram of the settings screen for setting up communications. Figure 2B This is a diagram of a selection screen for selecting a network. Figure 2C FIG. 1 is a diagram showing a completion screen showing completion of connection.

[0039] like Figure 2A As shown, the setting screen 200 includes a new setting button 201, a cancel button 202, and an OK button 203. The setting screen 200 is a screen for setting a connection with an external device such as an AP, etc. The setting screen 200 is displayed on the display unit 106 of the digital camera 100.

[0040] The new setting button 201 is a button for starting connection of the control unit 101 with an external device such as an AP.

[0041] The cancel button 202 is a button for canceling the connection of the control unit 101 with an external device such as an AP.

[0042] The OK button 203 is a button for deciding the operation of the digital camera 100. If the user selects the OK button 203 while the new setting button 201 is selected, the control unit 101 performs an AP scan. In this scan, an attempt is made to wirelessly receive a signal including an SSID and a BSSID from one AP or each of a plurality of APs.

[0043] like Figure 2B As shown, the selection screen 210 includes a connect button 211, a connect button 212, and a cancel button 213. The selection screen 210 is a screen for selecting an external device such as an AP to be connected. The selection screen 210 is displayed on the display unit 106 of the digital camera 100.

[0044] The connect button 211 is a button that allows the user to select an AP to which the digital camera 100 is to connect. If the connect button 211 is selected, the control unit 101 attempts to connect to the AP based on the displayed SSID and channel. For example, if the connect button 211 is selected, the control unit 101 attempts to connect to the AP having the SSID "Conon" and the channel "1ch".

[0045] The connect button 212 is a button that allows the user to select an AP to which the digital camera 100 is to connect. If the connect button 212 is selected, the control unit 101 attempts to connect to the AP based on the displayed SSID and channel. For example, if the connect button 212 is selected, the control unit 101 attempts to connect to the AP having the SSID "Conon" and the channel "36ch".

[0046] The cancel button 213 is a button that allows the user to cancel the connection between the digital camera 100 and an external device such as an AP.

[0047] like Figure 2C As shown, the completion screen 220 includes an OK button 221. The completion screen 220 is a screen displayed when the connection between the digital camera 100 and an external device such as an AP is completed. The completion screen 220 is displayed on the display unit 106 of the digital camera 100.

[0048] The OK button 221 is a button for confirming the completion of the connection between the digital camera 100 and the external device.

[0049] <System Configuration Including Digital Camera>

[0050] Next, refer to Figure 3 A system configuration including the digital camera 100 according to the present embodiment will be described. Figure 33 is a diagram showing a system configuration including the digital camera 100. The system includes the digital camera 100, and APs 301 and 302 each serving as an external device functioning as an access point.

[0051] The digital camera 100 is set so that it can connect to the AP 301 and the AP 302 having the SSID "Conon".

[0052] The AP 301 is set to SSID "Conon" and frequency band "2.4 GHz".

[0053] The AP 302 is set to SSID “Conon” and frequency band “6 GHz.” That is, the frequency band of the AP 301 is different from the frequency band of the AP 302 .

[0054] (First embodiment)

[0055] Will refer to Figure 4 and Figure 5 The roaming method according to the first embodiment will be described.

[0056] <Control Sequence of Digital Camera>

[0057] Will refer to Figure 4 A control sequence of the digital camera 100 according to the first embodiment will be described. Figure 4 is a sequence diagram illustrating processing between the digital camera and the AP according to the first embodiment.

[0058] In S401, the control unit 101 of the digital camera 100 accepts a connection start instruction from the user via the operation unit 105. For example, in the case Figure 2A As shown, with the setting screen 200 displayed on the display unit 106, the control unit 101 accepts user selection of the new setting button 201 and then accepts input of the OK button 203. In response, the control unit 101 determines that a connection start instruction has been accepted.

[0059] In S402 , the control unit 101 of the digital camera 100 performs scanning to attempt to wirelessly receive a signal including an SSID and a BSSID from one AP or each of a plurality of APs.

[0060] In S403, the control unit 101 of the digital camera 100 accepts a connection AP selection instruction from the user via the operation unit 105. For example, in the case Figure 2B As shown, in a state where the selection screen 210 is displayed on the display unit 106 , the control unit 101 accepts input of the connect button 211 .

[0061] In S404 , the control unit 101 of the digital camera 100 associates the SSID and ch of the AP corresponding to the connection AP selection instruction accepted in S403 as connection settings of the SSID and ch of the desired AP, and stores them in the work memory 104 .

[0062] In S405 , the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP to perform connection processing in cooperation with the AP.

[0063] In S406 , the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP.

[0064] In S407, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP, and establishes a wireless LAN connection with the AP. After the wireless LAN connection is established, for example, the control unit 101 Figure 2C As shown, a completion screen 220 is displayed on the display unit 106, and an input of an OK button 221 from the user is accepted. The control unit 101 transmits a connection completion notification to the AP, and receives a connection completion notification from the AP.

[0065] In S408, if the control unit 101 of the digital camera 100 determines that the SNR of the AP during connection (hereinafter referred to as the connection AP) has fallen below the SNR threshold, the control unit 101 specifies the AP of the desired SSID stored in the working memory 104 and scans for it. During the scan, the control unit 101 obtains the frequency band of the connection AP and the frequency band of the roaming target AP. Note that in this embodiment, the control unit 101 obtains the frequency band of the connection AP in S408, but the frequency band of the connection AP may also be obtained in S407, which is the timing when the digital camera 100 connects to the connection AP.

[0066] In S409, the control unit 101 of the digital camera 100 determines whether the frequency bands of the connected AP and the roaming target AP are different. If the control unit 101 determines that the frequency bands of the connected AP and the roaming target AP are different, the control unit 101 changes the SNR threshold value, which serves as the SNR condition for roaming. For example, if the frequency band of the connected AP is "2.4 GHz" and the frequency band of the roaming target AP is "6 GHz," the control unit 101 determines that the frequency band of the roaming target AP is larger than the frequency band of the connected AP and changes the SNR condition (that is, the SNR threshold value) serving as the roaming condition from the initially set value of "15" to "20." In other words, if the frequency band of the roaming target AP is larger than the frequency band of the connected AP, the control unit 101 relaxes the roaming condition to facilitate roaming. When the frequency band of the connected AP is 6 GHz and the frequency band of the roaming destination AP is 2.4 GHz, control unit 101 determines that the frequency band of the roaming destination AP is smaller than the frequency band of the connected AP, and changes the SNR condition (that is, the SNR threshold) serving as the roaming condition from the initially set value of 15 to 10. In other words, when the frequency band of the roaming destination AP is smaller than the frequency band of the connected AP, control unit 101 tightens the roaming condition to make roaming difficult.

[0067] In S410 , if the control unit 101 of the digital camera 100 determines that the SNR of the connection AP is lower than the SNR threshold and the roaming condition is satisfied, the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP to perform connection processing in cooperation with the AP.

[0068] In S411 , the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP.

[0069] In S412, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP and establishes a wireless LAN connection with the AP. After establishing the wireless LAN connection, the control unit 101 transmits a connection completion notification to the AP and receives a connection completion notification from the AP.

[0070] <Control Process of Digital Camera>

[0071] Will refer to Figure 5 A control procedure of the digital camera 100 according to the first embodiment will be described. Figure 5 is a flowchart illustrating processing of the digital camera according to the first embodiment.

[0072] In step S501, the control unit 101 of the digital camera 100 determines whether it has accepted a connection start instruction from the user. If the control unit 101 determines that it has accepted a connection start instruction, the control unit 101 advances the process to step S502. If the control unit 101 determines that it has not accepted a connection start instruction, the control unit 101 repeats the process in step S501. The process in step S501 is the same as that in step S502. Figure 4 Corresponding to S401 in.

[0073] In step S502, the control unit 101 of the digital camera 100 performs scanning to attempt to wirelessly receive a signal including an SSID and a BSSID from one AP or each of a plurality of APs. The processing in step S502 is the same as that in step S503. Figure 4 Corresponding to S402 in.

[0074] In step S503, the control unit 101 of the digital camera 100 determines whether it has accepted a connection AP selection instruction. If the control unit 101 determines that it has accepted a connection AP selection instruction, it advances the process to step S504. If the control unit 101 determines that it has not accepted a connection AP selection instruction, it repeats the process in step S503.

[0075] In step S504, the control unit 101 of the digital camera 100 associates the SSID and ch of the AP included in the accepted connection AP selection instruction as the connection setting of the SSID and ch of the desired AP, and stores them in the working memory 104. The processing in step S504 is the same as that in step S506. Figure 4 Corresponding to S404 in.

[0076] In step S505, the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP to perform connection processing in cooperation with the AP. The processing in step S505 is the same as that in step S506. Figure 4 Corresponding to S405 in.

[0077] In step S506, the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP. The processing in step S506 is the same as that in step S506. Figure 4 Corresponding to S406 in.

[0078] In step S507, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP, and establishes a wireless LAN connection with the AP. After the establishment, the control unit 101 sends a connection completion notification to the AP and receives a connection completion notification from the AP. The processing in step S507 is the same as that in step S508. Figure 4 Corresponding to S407 in.

[0079] In step S508, the control unit 101 of the digital camera 100 determines whether a connection termination instruction has been received from the user. If the control unit 101 determines that the connection termination instruction has been received, the control unit 101 ends the process. If the control unit 101 determines that the connection termination instruction has not been received, the control unit 101 advances the process to step S509.

[0080] In step S509, the control unit 101 of the digital camera 100 determines whether the SNR of the connected AP has fallen below the SNR threshold. If the control unit 101 determines that the SNR of the connected AP has fallen below the SNR threshold, the control unit 101 advances the process to step S510. If the control unit 101 determines that the SNR of the connected AP has not fallen below the SNR threshold, the control unit 101 returns to the process in step S508 to repeat the process from step S508 onwards.

[0081] In step S510, the control unit 101 of the digital camera 100 specifies the AP of the desired SSID stored in the work memory 104 and performs scanning. In the scanning, the control unit 101 obtains the frequency band of the connected AP and the frequency band of the roaming target AP. The processing in step S510 is the same as that in step S511. Figure 4 Corresponding to S408 in.

[0082] In step S511, the control unit 101 of the digital camera 100 determines whether the frequency band of the roaming AP is larger than the frequency band of the connected AP. If the control unit 101 determines that the frequency band of the roaming AP is larger than the frequency band of the connected AP, the control unit 101 advances the process to step S512. If the control unit 101 determines that the frequency band of the roaming AP is not larger than the frequency band of the connected AP, the control unit 101 advances the process to step S513.

[0083] In step S512, the control unit 101 of the digital camera 100 changes the SNR condition. Here, the change of the SNR condition is to increase the SNR threshold value serving as the roaming condition. The processing in step S512 is the same as that in step S513. Figure 4 Corresponding to S409 in.

[0084] In step S513, the control unit 101 of the digital camera 100 changes the SNR condition. Here, the change of the SNR condition is to lower the SNR threshold value serving as the roaming condition. The processing in step S513 is the same as that in step S514. Figure 4 Corresponding to S409 in.

[0085] In step S514, the control unit 101 of the digital camera 100 determines whether the roaming condition is met based on the SNR of the connected AP and the SNR threshold. If the SNR of the connected AP is lower than the SNR threshold, the control unit 101 determines that the roaming condition is met and advances the process to step S515 to execute roaming. If the SNR of the connected AP is not lower than the SNR threshold, the control unit 101 determines that the roaming condition is not met and returns to the process in step S508 without performing roaming.

[0086] In step S515, the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP which also serves as the roaming target to perform connection processing in cooperation with the AP. The processing in step S515 is the same as that in step S516. Figure 4 Corresponding to S410 in.

[0087] In step S516, the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP. The processing in step S516 is the same as that in step S517. Figure 4 Corresponding to S411 in.

[0088] In step S517, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP, and establishes a wireless LAN connection with the AP. After the establishment, the control unit 101 sends a connection completion notification to the AP and receives a connection completion notification from the AP. The processing in step S517 is the same as that in step S518. Figure 4 Corresponding to S412 in.

[0089] According to the first embodiment, the digital camera 100 obtains the frequency band of the connected AP and the frequency band of the roaming target AP. If the digital camera 100 determines that the frequency band of the roaming target AP is greater than the frequency band of the connected AP, the digital camera 100 changes the SNR threshold, which serves as the SNR condition for roaming, to a higher value to facilitate roaming. If the digital camera 100 determines that the roaming condition is met, the digital camera 100 executes roaming. According to this embodiment, the decrease in throughput after roaming can be reduced, and roaming to a frequency band with higher throughput can be easily performed.

[0090] (Second embodiment)

[0091] Will refer to Figure 6 7 to illustrate the roaming method according to the second embodiment.

[0092] <Control Sequence of Digital Camera>

[0093] Will refer to Figure 6 A control sequence of the digital camera 100 according to the second embodiment will be described. Figure 6is a sequence diagram illustrating processing between a digital camera and an AP according to the second embodiment.

[0094] In S601, the control unit 101 of the digital camera 100 accepts a connection start instruction from the user via the operation unit 105. For example, in the case Figure 2A As shown, in a state where the setting screen 200 is displayed on the display unit 106, the control unit 101 accepts the user's selection of the new setting button 201 and then accepts input of the OK button 203. In response to this, the control unit 101 accepts a connection start instruction.

[0095] In S602 , the control unit 101 of the digital camera 100 performs scanning to attempt to wirelessly receive a signal including an SSID and a BSSID from one AP or each of a plurality of APs.

[0096] In S603, the control unit 101 of the digital camera 100 accepts a connection AP selection instruction from the user via the operation unit 105. For example, in the case Figure 2B As shown, in a state where the selection screen 210 is displayed on the display unit 106 , the control unit 101 accepts input of the connect button 212 .

[0097] In S604 , the control unit 101 of the digital camera 100 associates the SSID and ch of the AP corresponding to the connection AP selection instruction received in S603 as connection settings of the SSID and ch of the desired AP, and stores them in the work memory 104 .

[0098] In S605 , the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP to perform connection processing in cooperation with the AP.

[0099] In S606 , the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP.

[0100] In S607, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP, and establishes a wireless LAN connection with the AP. After the wireless LAN connection is established, for example, the control unit 101 Figure 2C As shown, a completion screen 220 is displayed on the display unit 106, and an input of an OK button 221 from the user is accepted. The control unit 101 transmits a connection completion notification to the AP, and receives a connection completion notification from the AP.

[0101] In S608, if the control unit 101 of the digital camera 100 determines that the RSSI of the connected AP has fallen below the RSSI threshold and has continued to decline for the communication deterioration determination time, the control unit 101 specifies an AP with the desired SSID stored in the working memory 104 and performs a scan. During the scan, the control unit 101 obtains the frequency band of the connected AP and the frequency band of the roaming AP. For example, if the control unit 101 determines that the RSSI of the connected AP has fallen below the RSSI threshold for the communication deterioration determination time "30 seconds (sec)", the control unit 101 specifies an AP with the desired SSID "Conon" stored in the working memory 104 and performs a scan. During the scan, the control unit 101 obtains the frequency band "2.4 GHz" of the connected AP and the frequency band "6 GHz" of the roaming AP.

[0102] In S609, if the control unit 101 of the digital camera 100 determines that the frequency bands of the connected AP and the roaming target AP are different, the control unit 101 changes the RSSI threshold value, which serves as the RSSI condition for roaming. For example, if the frequency band of the connected AP is 6 GHz and the frequency band of the roaming target AP is 2.4 GHz, the control unit 101 determines that the frequency band of the roaming target AP is smaller than the frequency band of the connected AP and changes the RSSI threshold value, which serves as the RSSI condition for roaming, from the initially set value of -50 to -75. In other words, if the frequency band of the roaming target AP is smaller than the frequency band of the connected AP, the control unit 101 tightens the roaming condition to make roaming difficult. If the frequency band of the connected AP is 2.4 GHz and the frequency band of the roaming target AP is 6 GHz, the control unit 101 determines that the frequency band of the roaming target AP is larger than the frequency band of the connected AP and changes the RSSI threshold value, which serves as the RSSI condition for roaming, from the initially set value of -50 to -25. In other words, when the frequency band of the roaming target AP is larger than the frequency band of the connected AP, the control unit 101 relaxes the roaming conditions to facilitate roaming.

[0103] In S610, if the control unit 101 of the digital camera 100 determines that the frequency band of the roaming target AP is smaller than the frequency band of the connected AP, the control unit 101 changes the communication deterioration determination time condition, which serves as a roaming condition. For example, the control unit 101 changes the communication deterioration determination time condition, which serves as a roaming condition, from the initially set "30 seconds" to "60 seconds." In other words, when the frequency band of the roaming target AP is smaller than the frequency band of the connected AP, the control unit 101 makes roaming difficult.

[0104] In S611 , if the control unit 101 of the digital camera 100 determines that the roaming condition is satisfied, the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP to perform connection processing in cooperation with the AP.

[0105] In S612 , the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP.

[0106] In S613, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP and establishes a wireless LAN connection with the AP. After establishing the wireless LAN connection, the control unit 101 transmits a connection completion notification to the AP and receives a connection completion notification from the AP.

[0107] <Control Process of Digital Camera>

[0108] Will refer to Figure 7A and Figure 7B A control procedure of the digital camera 100 according to the second embodiment will be described. Figure 7A and Figure 7B is a flowchart illustrating processing of the digital camera according to the second embodiment.

[0109] In step S701, the control unit 101 of the digital camera 100 determines whether it has accepted a connection start instruction. If the control unit 101 determines that it has accepted a connection start instruction, the control unit 101 advances the process to step S702. If the control unit 101 determines that it has not accepted a connection start instruction, the control unit 101 repeats the process in step S701. The process in step S701 is the same as that in step S703. Figure 6 Corresponding to S601 in.

[0110] In step S702, the control unit 101 of the digital camera 100 performs scanning to attempt to wirelessly receive a signal including an SSID and a BSSID from one AP or each of a plurality of APs. The processing in step S702 is the same as that in step S703. Figure 6 Corresponding to S602 in.

[0111] In step S703, the control unit 101 of the digital camera 100 determines whether it has accepted a connection AP selection instruction. If the control unit 101 determines that it has accepted a connection AP selection instruction, it advances the process to step S704. If the control unit 101 determines that it has not accepted a connection AP selection instruction, it repeats the process in step S703.

[0112] In step S704, the control unit 101 of the digital camera 100 associates the SSID and ch included in the received connection AP selection instruction as connection settings of the SSID and ch of the desired AP, and stores them in the working memory 104. The processing in step S704 is the same as that in step S705. Figure 6 Corresponding to S604 in.

[0113] In step S705, the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP to perform connection processing in cooperation with the AP. The processing in step S705 is the same as that in step S706. Figure 6 Corresponding to S605 in.

[0114] In step S706, the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP. The processing in step S706 is the same as that in step S707. Figure 6 Corresponding to S606 in .

[0115] In step S707, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP, and establishes a wireless LAN connection with the AP. After the establishment, the control unit 101 transmits a connection completion notification to the AP and receives a connection completion notification from the AP. The processing in step S707 is the same as that in step S708. Figure 6 Corresponding to S607 in.

[0116] In step S708, the control unit 101 of the digital camera 100 determines whether a connection termination instruction has been accepted. If the control unit 101 determines that a connection termination instruction has been accepted, the control unit 101 ends the process. If the control unit 101 determines that a connection termination instruction has not been accepted, the control unit 101 advances the process to step S709.

[0117] In step S709, the control unit 101 of the digital camera 100 determines whether the RSSI of the connected AP has fallen below the RSSI threshold. If the control unit 101 determines that the RSSI of the connected AP has fallen below the RSSI threshold, the control unit 101 advances the process to step S710. If the control unit 101 determines that the RSSI of the connected AP has not fallen below the RSSI threshold, the control unit 101 returns to the process in step S708 to repeat the process from step S708 onwards.

[0118] In step S710, the control unit 101 of the digital camera 100 determines whether the time during which the RSSI of the connected AP has fallen below the RSSI threshold has become longer than the communication deterioration determination time. If the control unit 101 determines that the time during which the RSSI of the connected AP has fallen below the RSSI threshold has become longer than the communication deterioration determination time, the control unit 101 advances the process to step S711. If the control unit 101 determines that the time during which the RSSI of the connected AP has fallen below the RSSI threshold has not become longer than the communication deterioration determination time, the control unit 101 returns to the process in step S708.

[0119] In step S711, the control unit 101 of the digital camera 100 specifies the AP of the desired SSID stored in the work memory 104 and performs scanning. In the scanning, the control unit 101 obtains the frequency band of the connected AP and the frequency band of the roaming target AP. The processing in step S711 is the same as that in step S712. Figure 6 Corresponding to S608 in.

[0120] In step S712, the control unit 101 of the digital camera 100 determines whether the frequency band of the roaming AP is smaller than the frequency band of the connected AP. If the control unit 101 determines that the frequency band of the roaming AP is smaller than the frequency band of the connected AP, the control unit 101 advances the process to step S713. If the control unit 101 determines that the frequency band of the roaming AP is not smaller than the frequency band of the connected AP, the control unit 101 advances the process to step S715.

[0121] In step S713, the control unit 101 of the digital camera 100 changes the RSSI condition. Here, the change of the RSSI condition is to lower the RSSI threshold value serving as the roaming condition. The processing in step S713 is the same as that in step S714. Figure 6 Corresponding to S609 in .

[0122] In step S714, the control unit 101 of the digital camera 100 changes the time condition. Here, the change in the time condition is to extend the communication deterioration determination time serving as the roaming condition. The processing in step S714 is the same as that in step S715. Figure 6 Corresponding to S610 in.

[0123] In step S715, the control unit 101 of the digital camera 100 changes the RSSI condition. Here, the change of the RSSI condition is to increase the RSSI threshold value serving as the roaming condition. The processing in step S713 is the same as that in step S714. Figure 6 Corresponding to S609 in .

[0124] In step S716, the control unit 101 of the digital camera 100 changes the time condition. Here, the change in the time condition is to shorten the communication deterioration determination time serving as the roaming condition. The processing in step S716 is the same as that in step S717. Figure 6 Corresponding to S610 in.

[0125] In step S717, the control unit 101 of the digital camera 100 determines whether roaming conditions are met based on the RSSI threshold and the communication deterioration determination time. If the control unit 101 determines that the roaming conditions are met, it advances the process to step S718 to execute roaming. More specifically, if the RSSI of the connected AP falls below the RSSI threshold and the decrease time becomes longer than the communication deterioration determination time, the control unit 101 determines that the roaming conditions are met. In contrast, if the control unit 101 determines that the roaming conditions are not met, it returns to the process in step S708 without performing roaming.

[0126] In step S718, the control unit 101 of the digital camera 100 sends a connection request to the connection attempt target AP which also serves as a roaming target to perform connection processing in cooperation with the AP. The processing in step S718 is the same as that in step S719. Figure 6 Corresponding to S611 in.

[0127] In step S719, the control unit 101 of the digital camera 100 receives a connection OK notification from the connection attempt target AP. The processing in step S719 is the same as that in step S719. Figure 6 Corresponding to S612 in.

[0128] In step S720, the control unit 101 of the digital camera 100 determines that the connection attempt target AP is the desired AP, and establishes a wireless LAN connection with the AP. After the establishment, the control unit 101 sends a connection completion notification to the AP and receives a connection completion notification from the AP. The processing in step S720 is the same as that in step S721. Figure 6 Corresponding to S613 in.

[0129] According to the second embodiment, the digital camera 100 obtains the frequency band of the connected AP and the frequency band of the roaming target AP. If the digital camera 100 determines that the frequency band of the roaming target AP is smaller than the frequency band of the connected AP, the digital camera 100 changes the RSSI threshold, which serves as the RSSI condition for roaming, to a lower value to make handover difficult. Furthermore, if the digital camera 100 determines that the frequency band of the roaming target AP is smaller than the frequency band of the connected AP, the digital camera 100 changes the communication deterioration determination time, which serves as the roaming condition, to a higher value to make handover difficult. If the digital camera 100 determines that the roaming condition is met, the digital camera 100 executes roaming. Therefore, according to this embodiment, the decrease in throughput after roaming can be reduced, and roaming to a frequency band with higher throughput can be easily performed.

[0130] The preferred embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention.

[0131] The above embodiments may be combined, or some processes may be omitted. For example, in the first embodiment, when the SNR of the connected AP falls below the SNR threshold for a period of time exceeding the communication deterioration judgment time, the control unit 101 may change the SNR threshold. In the second embodiment, when the RSSI of the connected AP falls below the RSSI threshold, the control unit 101 may change the RSSI threshold even if the communication deterioration judgment time has not elapsed. The control unit 101 may be configured to determine roaming conditions based on either the SNR or the RSSI, with the user being able to select either the SNR threshold or the RSSI threshold.

[0132] The above embodiment describes an example in which the frequency bands of the connected AP and the roaming AP are compared, and the SNR threshold or RSSI threshold is changed regardless of which frequency band is larger. However, the present invention is not limited to this. For example, the threshold may be changed only when the frequency band of the roaming AP is larger than the frequency band of the connected AP. Alternatively, the threshold may be changed only when the frequency band of the roaming AP is smaller than the frequency band of the connected AP.

[0133] For example, in the first embodiment described above, the processing from S408 is executed when the SNR falls below the SNR threshold. However, the conditions for executing the processing from S408 are not limited thereto. For example, instead of or in addition to the above conditions, the processing from S408 may be executed when the signal strength of the connected AP falls below a strength threshold (e.g., 15).

[0134] For example, in the second embodiment described above, the processing from S608 is executed when the RSSI falls below the RSSI threshold. However, the conditions for executing the processing from S608 are not limited to this. For example, instead of or in addition to the above conditions, the processing from S608 may be executed when the signal strength of the connected AP falls below the strength threshold (e.g., 15) for the communication deterioration determination time (e.g., 30 seconds).

[0135] Other embodiments

[0136] The embodiments of the present invention can also be implemented by the following method, that is, software (including computer program products of computer programs / instructions) that perform the functions of the above-mentioned embodiments is provided to a system or device through a network or various storage media, and a computer (central processing unit (CPU), microprocessing unit (MPU)) of the system or device reads and executes the computer program / instructions.

[0137] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications, equivalent structures and functions.

[0138] This application claims the benefit of Japanese Patent Application No. 2024-021449, filed February 15, 2024, which is hereby incorporated by reference herein in its entirety.

Claims

1. A communication device, comprising: an obtaining unit configured to obtain information of a plurality of access points in different frequency bands; a changing unit configured to compare a frequency band during connection with a frequency band of a roaming object and change a roaming condition for performing roaming; as well as The execution unit is configured to execute roaming if the signal of the frequency band during the connection period meets the roaming condition.

2. The communication device according to claim 1, wherein The changing unit changes a signal-to-noise ratio condition, ie, an SNR condition, which is the roaming condition.

3. The communication device according to claim 1, wherein The changing unit changes a received signal strength indicator condition (RSSI) as the roaming condition. The communication device according to claim 1 , wherein: The changing unit changes a judgment time for judging a time at which communication time deteriorates as the roaming condition. The communication device according to claim 2 , wherein: The changing unit relaxes the SNR condition in a case where the frequency band of the roaming object is larger than the frequency band during connection. The communication device according to claim 2 , wherein: In a case where the frequency band of the roaming object is smaller than the frequency band during connection, the changing unit tightens the SNR condition.

7. The communication device according to claim 3, wherein: The changing unit relaxes the RSSI condition in a case where the frequency band of the roaming object is larger than the frequency band during connection. The communication device according to claim 3 , wherein: The changing unit tightens the RSSI condition in a case where the frequency band of the roaming object is smaller than the frequency band during connection.

9. The communication device according to claim 4, wherein: The changing unit shortens the determination time in a case where the frequency band of the roaming object is larger than the frequency band during connection.

10. The communication device according to claim 4, wherein: The changing unit extends the determination time in a case where the frequency band of the roaming object is smaller than the frequency band during connection.

11. A communication method, comprising: Obtain information about multiple access points in different frequency bands; comparing a frequency band during connection with a frequency band of a roaming target to change a roaming condition for performing roaming; as well as If the signal of the frequency band during the connection period satisfies the roaming condition, roaming is performed.

12. A non-transitory computer-readable storage medium storing a computer program which, when read and executed by a computer, causes the computer to function as: an obtaining unit configured to obtain information of a plurality of access points in different frequency bands; a changing unit configured to compare a frequency band during connection with a frequency band of a roaming object and change a roaming condition for performing roaming; as well as The execution unit is configured to execute roaming if the signal of the frequency band during the connection period meets the roaming condition.

13. A computer program product comprising a computer program which, when read and executed by a computer, causes the computer to function as: an obtaining unit configured to obtain information of a plurality of access points in different frequency bands; a changing unit configured to compare a frequency band during connection with a frequency band of a roaming object and change a roaming condition for performing roaming; as well as The execution unit is configured to execute roaming if the signal of the frequency band during the connection period meets the roaming condition.

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