Communication device, computer program for the communication device, and method executed by the communication device

Abstract

To provide a technique capable of appropriately switching a communication channel used in a search processing depending on whether or not a first wireless connection is established between a communication device and an access point.SOLUTION: A communication device establishes a first wireless connection with an access point according to a first wireless communication scheme, and searches for an external device. The communication device executes a first search processing using a first communication channel according to a second wireless communication scheme and a second search processing using the first communication channel according to a third wireless communication scheme in a situation in which the first wireless connection with the access point is established. In a situation where the first wireless connection with the access point is not established, a third search processing using the second communication channel is executed according to the second wireless communication scheme, and a fourth search processing using the third communication channel is executed according to the third wireless communication scheme.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This specification discloses a communication device that performs a search process. [Background technology]

[0002] Patent Document 1 discloses a system including a plurality of NAN devices and an access point. When a first NAN device is performing communication compliant with a communication standard other than the Wi-Fi NAN standard, the first NAN device establishes a NAN data link using the same operating channel as the operating channel for that communication. On the other hand, when the first NAN device is not performing communication compliant with a communication standard other than the Wi-Fi NAN standard, the first NAN device establishes a NAN data link using an operating channel in which the first NAN device can operate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-083482 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 does not take into consideration at all switching the operating channel of the NAN device depending on whether or not a wireless connection has been established between the NAN device and the access point.

[0005] This specification provides a technology that can appropriately switch the communication channel used for search processing depending on whether a first wireless connection is established between a communication device and an access point. [Means for solving the problem]

[0006] This specification discloses a communication device. The communication device may include a wireless interface capable of communicating according to a first wireless communication method, a second wireless communication method, and a third wireless communication method, a first establishment unit that establishes a first wireless connection with an access point via the wireless interface according to the first wireless communication method, and a search unit that searches for an external device via the wireless interface. In a first situation in which the first wireless connection with the access point is established, the search unit may execute a first search process using a first communication channel according to the second wireless communication method and a second search process using the first communication channel according to the third wireless communication method, and in a second situation in which the first wireless connection with the access point is not established, a third search process using a second communication channel according to the second wireless communication method and a fourth search process using a third communication channel different from the second communication channel according to the third wireless communication method.

[0007] According to the above configuration, the communication device executes the first and second search processes using the same communication channel in the first situation, and executes the third and fourth search processes using different communication channels in the second situation. With this configuration, the communication channel used for the search processes can be appropriately switched depending on whether the first wireless connection is established between the communication device and the access point.

[0008] A computer program for implementing the above-described communication device, a computer-readable storage medium storing the computer program, and a method executed by the above-described communication device are also novel and useful. Also novel and useful is a communication system including the communication device, an access point, and an external device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows the configuration of a communication system. [Figure 2] 1 shows an example of a channel table. [Figure 3] The sequence diagram for Case A is shown below. [Figure 4] 10 shows the transition of communication channels in case B. [Figure 5] 10 shows the transition of communication channels in case C. [Figure 6] 10 shows the transition of communication channels in case D. [Figure 7] 10 shows the transition of communication channels in case E. [Figure 8] 10 shows the transition of communication channels in case F. DETAILED DESCRIPTION OF THE INVENTION

[0010] (First Example) (Configuration of communication system 2; Figure 1) As shown in FIG. 1, the communication system 2 includes an MFP 10, a terminal device 100, a first access point 6A, and a second access point 6B. Hereinafter, the access points will be referred to as "AP." In this embodiment, the first AP 6A uses channel 1 of the 2.4 GHz band as a communication channel, and the second AP 6B uses channel 2 of the 2.4 GHz band as a communication channel. Hereinafter, the first AP 6A and the second AP 6B may be collectively referred to as "AP6."

[0011] (MFP10 configuration) The MFP 10 is a peripheral device (i.e., a peripheral device such as a PC) that can execute printing and scanning functions. The MFP 10 has a device name "DV1." The device name is a name given by an MFP administrator. The MFP 10 includes an operation unit 12, a display unit 14, a print execution unit 16, a scan execution unit 18, and a Wi-Fi interface 20. Hereinafter, the interface will be referred to as "I / F."

[0012] The operation unit 12 is an I / F that allows a user to input various information to the MFP 10. The operation unit 12 includes, for example, a touch panel for displaying software keys (operation objects), hardware keys, or both. The hardware keys include, for example, buttons or switches. The display unit 14 is a display or panel for displaying various information. The display is, for example, a liquid crystal display or an organic EL display. The panel may or may not be a touch panel. The panel is, for example, a liquid crystal panel or an organic EL panel.

[0013] The print execution unit 16 includes an inkjet, electrophotographic, or thermal print engine. An inkjet print engine includes a print head that ejects ink droplets. An electrophotographic print engine includes a photosensitive element and an exposure device that emits light to expose the photosensitive element. A thermal print engine includes a print head that generates heat using a heater. The scan execution unit 18 includes a scan mechanism such as a CIS or CCD.

[0014] The Wi-Fi I / F 20 is a wireless interface for performing wireless communication according to the Wi-Fi standard. The Wi-Fi standard is a wireless communication standard for performing wireless communication according to, for example, the 802.11 standard of the Institute of Electrical and Electronics Engineers, Inc. (IEEE) and standards equivalent thereto (e.g., 802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, etc.). The carrier frequency for wireless communication according to the Wi-Fi standard is, for example, the 1.0 GHz band, 2.4 GHz band, 5.0 GHz band, or 6.0 GHz band. In this embodiment, the 2.4 GHz band is used. The MFP 10 can establish a wireless connection with the AP 6 via the Wi-Fi I / F 20 using the Service Set Identifier (SSID) and password of the wireless network formed by the AP 6. Hereinafter, the wireless communication standard for establishing a wireless connection between the MFP 10 and the AP 6 will be referred to as the "normal Wi-Fi standard." Furthermore, the wireless connection established between the MFP 10 and the AP 6 is referred to as an “AP connection.” The Wi-Fi I / F 20 is assigned a MAC address “MACx” as a MAC address that corresponds to the normal Wi-Fi method.

[0015] The Wi-Fi I / F20 also supports the Wi-Fi Aware standard established by the Wi-Fi Alliance. Wi-Fi Aware is also known as Wi-Fi Neighbor Awareness Network (NAN). In the following, Wi-Fi Aware will be referred to as "NAN." The NAN standard is a communications method described in the Wi-Fi Aware Specification Version 4.0 standard created by the Wi-Fi Alliance. In the following, a wireless connection established according to the NAN standard will be referred to as a "NAN connection."

[0016] Devices that can operate according to the NAN method can join a NAN cluster. Each device that joins a NAN cluster is assigned one of three roles: Master, Anchor Master, or Non-Master. A Master can share timer information, search for services, and invite devices to the NAN cluster. An Anchor Master can set timer information for synchronization in addition to the functions that a Master can perform. A Non-Master can share timer information and search for services, but cannot invite devices to a cluster. The Wi-Fi I / F 20 is assigned the MAC address "MACy" as the MAC address that corresponds to the NAN method.

[0017] Furthermore, the Wi-Fi I / F20 supports the Wi-Fi Direct (WFD) standard established by the Wi-Fi Alliance. Wi-Fi Direct is a registered trademark of the Wi-Fi Alliance. The WFD standard is a wireless communication standard described in the standard "Wi-Fi Direct Specification Version 1.9" created by the Wi-Fi Alliance. Hereinafter, a wireless connection established according to the WFD standard will be referred to as a "WFD connection." The Wi-Fi I / F20 is assigned the MAC address "MACz" that corresponds to the WFD standard. A device that can operate according to the WFD standard can operate in any of the following states: Group Owner (G / O), Client (CL), or Device.

[0018] The Wi-Fi I / F 20 can simultaneously establish an AP connection and a WFD connection. The Wi-Fi I / F 20 can simultaneously establish a normal Wi-Fi connection and a NAN connection. However, the Wi-Fi I / F 20 cannot simultaneously establish a WFD connection and a NAN connection.

[0019] The control unit 30 includes a CPU 32 and a memory 34. The memory 34 includes a main storage device and an auxiliary storage device. As an example, the main storage device includes a RAM and a cache memory. As an example, the auxiliary storage device may be a ROM, a flash memory, a solid state drive (SSD), a hard disk drive (HDD), or a combination thereof. A program 40 is stored in the auxiliary storage device of the memory 34. The CPU 32 performs various processes in accordance with the program loaded from the auxiliary storage device to the main storage device. The memory 34 also stores a NAN flag 42, a WFD flag 44, channel tables 46A to 46F, and WFD channel information 48. The NAN flag 42 indicates either "ON," which means that the MFP 10 is in a state capable of operating according to the NAN method, or "OFF," which means that the MFP 10 is in a state in which it is not in a state capable of operating according to the NAN method. The WFD flag 44 indicates either "ON," which means that the MFP 10 is in a state where it can operate according to the WFD method, or "OFF," which means that the MFP 10 is in a state where it cannot operate according to the WFD method. The WFD channel information 48 indicates communication channels that can be used when searching for external devices according to the WFD method. The WFD channel information 48 is information determined in advance by the Wi-Fi Alliance. The WFD channel information 48 indicates channels 1, 6, and 11 in the 2.4 GHz band. That is, the MFP 10 can selectively use channels 1, 6, and 11 in a first listen process and a second listen process, which will be described later.

[0020] (Configuration of terminal device 100) The terminal device 100 is a terminal device such as a mobile phone (for example, a smartphone), a PDA, a tablet PC, etc. The terminal device 100 includes an operation unit 112, a display unit 114, a Wi-Fi I / F 120, and a control unit .

[0021] The operation unit 112 is a user interface that enables a user to input various information to the terminal device 100. The operation unit 112 includes, for example, a touch panel for displaying software keys (operation objects), hardware keys, or both. The hardware keys include, for example, buttons or switches. The display unit 114 is a display or panel for displaying various information. The display is, for example, a liquid crystal display or an organic EL display. The panel may or may not be a touch panel. The panel is, for example, a liquid crystal panel or an organic EL panel. The Wi-Fi I / F 120 has a configuration similar to that of the Wi-Fi I / F 20 of the MFP 10.

[0022] The control unit 130 includes a CPU 132 and a memory 134. The memory 134 includes a main storage device and an auxiliary storage device. An OS program 140 and an application program 142 are stored in the auxiliary storage device of the memory 134. OS stands for Operating System. Hereinafter, the OS program 140 and the application program 142 will be referred to as "OS 140" and "application 142," respectively. The OS 140 controls the basic operations of the terminal device 100. The application 142 is a program for establishing a NAN connection.

[0023] (Configuration of channel tables 46A to 46F; Figure 2) The contents of channel tables 46A to 46F of MFP 10 will be described with reference to Figure 2. Channel tables 46A to 46F are tables for determining the communication channels corresponding to MAC addresses "MACy" and "MACz," respectively. Below, the communication channels corresponding to MAC addresses "MACx," "MACy," and "MACz," respectively, are referred to as "AP communication channel," "NAN communication channel," and "WFD communication channel."

[0024] Channel tables 46A-46F include MAC addresses, status information, and communication channels. The status information indicates either "Not Connected," which indicates that a wireless connection using the MAC address corresponding to the information has not been established, or "Connected," which indicates that a wireless connection using the MAC address corresponding to the information has been established. Channel tables 46A-46C and 46F also include communication channels when 6ch is congested. Here, "6ch is congested" refers to a situation in which wireless communication using 6ch is difficult, such as when the number of devices using 6ch around MFP 10 is greater than or equal to a predetermined number, or when the error rate of packets received using 6ch is greater than or equal to a predetermined value. Channel table 46E also includes communication channels when APch is congested. The AP channel is a communication channel used for AP connection. The AP channel is a communication channel determined by the AP. Note that the communication channel "1ch or 11ch" in channel tables 46A-46C means that either 1ch or 11ch may be determined as the communication channel. In this embodiment, when "1ch or 11ch" is determined as the communication channel, the MFP 10 determines 1ch as the communication channel out of 1ch and 11ch.

[0025] (Specific case) Specific cases realized by the communication system 2 of this embodiment will be described with reference to Figures 3 to 8. In the following, all communications between the MFP 10 and other devices are performed via the Wi-Fi I / F 20 of the MFP 10. Therefore, the phrase "via the Wi-Fi I / F 20" will be omitted. Also, for ease of understanding, the processes performed by the CPU of each device will be described with each device as the subject, rather than each CPU as the subject.

[0026] (Case A; Figure 3) Case A will be described with reference to FIG. 3. In the initial state of Case A, no AP connection, NAN connection, or WFD connection has been established. Also, in the initial state of Case A, the NAN flag 42 and WFD flag 44 of the MFP 10 are set to "OFF." Therefore, the MFP 10 performs operations according to the normal Wi-Fi method, and does not perform operations according to the NAN method or the WFD method. Because an AP connection has not been established, the MFP 10 performs normal search processing according to the normal Wi-Fi method. The normal search processing is processing for searching for an AP. In the normal search processing, the MFP 10 operates the Wi-Fi I / F 20 sequentially on channels 1 to 14 at 2.4 GHz.

[0027] At T10, the user executes a NAN flag setting operation on the MFP 10 to set the NAN flag 42 to “ON” and a WFD flag setting operation to set the WFD flag 44 to “ON.” As a result, the MFP 10 changes the WFD flag 44 and the NAN flag 42 to “ON” at T12. In response to the NAN flag 42 being changed to “ON,” the MFP 10 begins to operate as a Master in the NAN system. In response to the WFD flag 44 being changed to “ON,” the MFP 10 begins to operate in a device state in the WFD system. At this point, the AP connection, NAN connection, and WFD connection have not been established. In this case, the MFP 10 determines a NAN communication channel to be used in the NAN search process according to the NAN system and a WFD communication channel to be used in the first WFD search process according to the WFD system, and sequentially executes the normal search process, the NAN search process, and the first WFD search process. The procedure for determining the NAN communication channel and the WFD communication channel will be described. First, the MFP 10 identifies the channel table 46A in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "unconnected," "unconnected," and "unconnected," respectively. Next, the MFP 10 determines that 6ch is not congested. Next, the MFP 10 identifies the communication channels "6ch" and "6ch" corresponding to the NAN communication channel and the WFD communication channel, respectively, from the channel table 46A. Next, at T14, the MFP 10 sets the NAN communication channel and the WFD communication channel to "6ch." This allows the MFP 10 to perform a NAN search process using 6ch and a first WFD search process using the same 6ch. Note that the communication channel available for the NAN search process is predetermined to be 6ch by the Wi-Fi Alliance. The NAN search process is a process for searching for devices that can join a NAN cluster. During the NAN search process, the MFP 10 periodically transmits a NAN discovery beacon frame. The first WFD search process includes a scan process and a first listen process.The scan process is a process for sending a probe request and searching for devices in the G / O state. In the scan process, for example, in the 2.4 GHz band, channels 1 to 14 are used in sequence. The first listen process is a process for responding to a probe request sent from another device, and channel 6 set in T14 is used. Here, the "search process" includes both a configuration in which the MFP10 searches for an external device in response to sending a signal to the external device, and a configuration in which the MFP10 searches for an external device in response to receiving a signal from the external device.

[0028] At T20, the user executes an AP connection operation on the MFP 10 to establish an AP connection between the MFP 10 and the first AP 6A. The AP connection operation includes, for example, inputting the SSID and password of the first AP 6A. As a result, at T22, an AP connection process including a 4-way handshake is executed between the MFP 10 and the first AP 6A, and at T24, an AP connection using 1ch is established between the MFP 10 and the first AP 6A. In this case, at T26, the MFP 10 saves "1ch" as the AP communication channel and maintains the NAN communication channel and the WFD communication channel as "6ch."

[0029] At T30, the user executes an application activation operation on the terminal device 100 to activate the application 142. As a result, the terminal device 100 activates the application 142. In response to the activation of the application 142, the terminal device 100 operates as a NAN-based Non-Master. Therefore, at T40, the terminal device 100 receives a NAN discovery beacon frame from the MFP 10 in a NAN search process, joins the NAN cluster, and at T42, transmits a Subscribe to the MFP 10 to inquire about services that the MFP 10 can provide.

[0030] When the MFP 10 receives a Subscribe from the terminal device 100 in T42, the MFP 10 sends a Publish to the terminal device 100 in T44, indicating that the MFP 10 can provide a print service.

[0031] When the terminal device 100 receives Publish from the MFP 10 in T44, it causes the display unit 114 to display a list screen including print services compatible with the MFP 10 in T46. The user performs an operation on the terminal device 100 to select a print service compatible with the MFP 10 in T48. As a result, bootstraping is performed between the MFP 10 and the terminal device 100 in T50. Bootstrapping includes processing for checking the connection methods supported by each device, processing for determining the connection method to be used to establish a NAN connection, and the like.

[0032] At T52, the user executes a connection operation on the terminal device 100 to establish a NAN connection between the MFP 10 and the terminal device 100. As a result, at T60, pairing setup is executed between the MFP 10 and the terminal device 100. The pairing setup includes processing for strengthening encryption in accordance with the Simultaneous Authentication of Equals (SAE) method. Next, at T70, NDP setup is executed between the MFP 10 and the terminal device 100. The NDP setup includes processing for establishing a NAN connection and processing for determining a NAN communication channel, which is a communication channel used in the NAN connection. The procedure by which the MFP 10 determines the NAN communication channel will be described. The MFP 10 identifies the channel table 46F, which contains status information corresponding to MAC addresses "MACx," "MACy," and "MACz," respectively, that indicates "connected," "connected," and "unconnected." Next, the MFP 10 determines that 6ch is not congested. In this case, the MFP 10 identifies the communication channel "6ch" corresponding to the NAN communication channel from the channel table 46F. Then, in NDP Setup, the MFP 10 determines 6ch as the NAN communication channel. As a result, a NAN connection using 6ch is established between the MFP 10 and the terminal device 100. In this case, in T72, the MFP 10 maintains the AP communication channel, the NAN communication channel, and the WFD communication channel as "1ch," "6ch," and "6ch," respectively. In this way, when the terminal device 100 is found by the NAN search process, the MFP 10 determines that 6ch will be used in the NAN connection with the terminal device 100. With this configuration, the MFP 10 does not need to switch the NAN communication channel before and after the NAN connection is established.

[0033] At T80, the user executes an AP disconnection operation on the MFP 10 to disconnect the AP connection between the MFP 10 and the first AP 6A. As a result, at T82, the AP connection between the MFP 10 and the first AP 6A is disconnected. At T84, the MFP 10 resumes execution of the normal search process that operates Wi-Fi 20 sequentially on channels 1 to 14, and maintains the NAN communication channel and the WFD communication channel on "channel 6."

[0034] T90 to T96 are the same as T20 to T26, respectively. As a result, the AP connection is re-established between the MFP 10 and the first AP 6A. In this case, after the AP connection is re-established between the MFP 10 and the first AP 6A, the Wi-Fi I / F 20 operates on two communication channels. In this case, the MFP 10 does not disconnect the NAN connection.

[0035] (Case B; Figure 4) Case B will be described with reference to Fig. 4. The initial state of Case B is the state after T14 of Case A in Fig. 3. Therefore, the MFP 10 sequentially executes the normal search process, the NAN search process, and the first WFD search process.

[0036] At T110, a NAN connection is established between the MFP 10 and the terminal device 100. In this case, it is assumed that channel 6 is congested when the NAN connection is established. The MFP 10 identifies the channel table 46C in which the status information corresponding to MAC addresses “MACx,” “MACy,” and “MACz” is “unconnected,” “connected,” and “unconnected,” respectively. The MFP 10 then determines that channel 6 is congested. In this case, the MFP 10 identifies “channel 1,” a communication channel corresponding to the NAN communication channel when channel 6 is congested, from the channel table 46C. The MFP 10 then determines channel 1 as the NAN communication channel in NDP Setup. The MFP 10 then sets the NAN communication channel to “channel 1” and maintains the WFD communication channel at “channel 6.” In this way, when the MFP 10 finds the terminal device 100 through the NAN search process, the MFP 10 determines that channel 1 will be used in the NAN connection with the terminal device 100. With this configuration, the MFP 10 uses an appropriate communication channel, thereby preventing the inability to properly receive signals related to wireless communication, delays in wireless communication, and decreases in the communication speed of wireless communication.

[0037] At T112, an AP connection using 2ch is established between the MFP 10 and the second AP 6B. In this case, the AP communication channel, the NAN communication channel, and the WFD communication channel are “2ch,” “1ch,” and “6ch,” respectively. That is, the Wi-Fi I / F 20 operates on three communication channels. In a configuration using three communication channels, the Wi-Fi I / F 20 operates on each communication channel for a shorter period of time than in a configuration using two communication channels. This reduces the likelihood that the Wi-Fi I / F 20 can receive signals corresponding to each communication channel. Therefore, when the MFP 10 determines that the Wi-Fi I / F 20 operates on three communication channels, it executes processing to cause the Wi-Fi I / F 20 to operate on two communication channels. Specifically, the MFP 10 executes processing to terminate the NAN connection with the terminal device 100. Next, the MFP 10 identifies the channel table 46D in which the status information corresponding to each of the MAC addresses “MACx,” “MACy,” and “MACz” is “connected,” “unconnected,” and “unconnected,” respectively. Next, the MFP 10 identifies the communication channels “6ch” and “6ch” corresponding to the NAN communication channel and the WFD communication channel, respectively, from the channel table 46D. Next, the MFP 10 saves “2ch” as the AP communication channel, sets the NAN communication channel to “6ch,” and maintains the WFD communication channel at “6ch.” This puts the Wi-Fi I / F 20 into a state in which it operates using two communication channels. In this way, the MFP 10 disconnects the NAN connection with the terminal device 100 when an AP connection with the second AP 6B is established after the NAN connection with the terminal device 100 is established and the communication channel used in the AP connection is different from the communication channel used in the NAN connection. A user is more likely to use the MFP 10 to perform wireless communication using an AP connection than wireless communication using a NAN connection. Therefore, it is possible to prevent the Wi-Fi I / F 20 from operating on three communication channels, and to maintain a wireless connection that is likely to be used by the user.

[0038] (Case C; Figure 5) Case C will be described with reference to FIG. 5. The initial state of Case C is a state in which channel 6 is congested after T14 in Case A of FIG. 3. In this case, the MFP 10 identifies channel table 46A in which the states corresponding to MAC addresses “MACx,” “MACy,” and “MACz” are “unconnected,” “unconnected,” and “unconnected,” respectively. The MFP 10 then determines that channel 6 is congested. The MFP 10 then identifies, from channel table 46A, “channel 1,” the communication channel for when channel 6 is congested, corresponding to the WFD communication channel. The MFP 10 then maintains the NAN communication channel at “channel 6” and sets the WFD communication channel to “channel 1.” As a result, in this state, the MFP 10 sequentially executes a normal search process according to the normal Wi-Fi method, a NAN search process according to the NAN method, and a second WFD search process according to the WFD method. The second WFD search process includes a scan process and a second listen process. The second Listen process is similar to the first Listen process, except that 1ch is used.

[0039] At T210, an AP connection using 2ch is established between the MFP 10 and the second AP 6B. In this case, the MFP 10 identifies the channel table 46D in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "connected," "unconnected," and "unconnected," respectively. Next, the MFP 10 determines that 6ch is congested. Next, the MFP 10 identifies the communication channels "6ch" and "6ch," corresponding to the NAN communication channel and the WFD communication channel, respectively, from the channel table 46D. In this case, the MFP 10 saves "2ch" as the AP communication channel, maintains the NAN communication channel at "6ch," and sets the WFD communication channel to "6ch."

[0040] At T212, a NAN connection is established between the MFP 10 and the terminal device 100. The MFP 10 identifies the channel table 46F in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "connected," "connected," and "unconnected," respectively, and determines that 6ch is congested. Next, the MFP 10 identifies the communication channels "APch" and "6ch" corresponding to the MAC addresses "MACy" and "MACz" when 6ch is congested from the channel table 46F. In this case, when establishing a NAN connection with the terminal device 100, the MFP 10 determines 2ch, which corresponds to APch, as the NAN communication channel. As a result, the MFP 10 maintains the AP communication channel at "2ch," sets the NAN communication channel to "2ch," and maintains the WFD communication channel at "6ch."

[0041] At T220, the AP connection between the MFP 10 and the second AP 6B is disconnected. In this case, the MFP 10 resumes execution of the normal search process. Note that after T220, the communication channel "6ch" corresponding to the NAN communication channel in the channel table 46D is different from the current NAN communication channel "2ch." However, while the NAN connection is established, the NAN communication channel cannot be changed. Therefore, even if the NAN communication channel in the channel table 46D is different from the current NAN communication channel, the NAN communication channel is not changed.

[0042] At T222, an AP connection using 1ch is established between the MFP 10 and the first AP 6A. Therefore, the AP communication channel, NAN communication channel, and WFD communication channel become "1ch," "2ch," and "6ch," respectively. In this case, the MFP 10 determines that the Wi-Fi I / F 20 operates on three communication channels and executes the same processing as that after T112 in FIG. 4. Specifically, the MFP 10 executes processing to disconnect the NAN connection. As a result, the MFP 10 saves "1ch" as the AP communication channel, sets the NAN communication channel to "6ch," and maintains the WFD communication channel at "6ch." This puts the Wi-Fi I / F 20 into a state where it operates on two communication channels.

[0043] (Effects of Cases A to C) As shown in case C, when an AP connection is not established and 6ch is congested, the MFP 10 executes a NAN search process using communication channel "6ch" and a second WFD search process using communication channel "1ch." On the other hand, as shown in case A in Fig. 3, when an AP connection is not established and 6ch is not congested, the MFP 10 executes a NAN search process using communication channel "6ch" and a first WFD search process using communication channel "6ch." With this configuration, it is possible to appropriately switch the communication channel used in the search process depending on whether 6ch is congested.

[0044] (Case D; Figure 6) Case D will be described with reference to Fig. 6. The initial state of Case D is the state after T14 of Case A in Fig. 3. Therefore, the MFP 10 sequentially executes the normal search process, the NAN search process, and the first WFD search process.

[0045] At T310, an AP connection using 1ch is established between the MFP 10 and the first AP 6A. In this case, the MFP 10 saves "1ch" as the AP communication channel, and maintains the NAN communication channel and the WFD communication channel as "6ch," similar to T26 in FIG. 3.

[0046] At T312, a WFD connection is established between the MFP 10 and the terminal device 100. The MFP 10 identifies a channel table 46E in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "connected," "unconnected," and "connected," respectively. In this case, the MFP 10 identifies, from the channel table 46E, the communication channels "6ch" and "APch" corresponding to the NAN communication channel and the WFD communication channel, respectively. Then, when establishing a WFD connection with the terminal device 100, the MFP 10 determines 1ch, which corresponds to APch, as the WFD communication channel. As a result, the MFP 10 maintains the AP communication channel at "1ch," maintains the NAN communication channel at "6ch," and sets the WFD communication channel to "1ch." In this way, when the terminal device 100 is found by the first WFD search process, the MFP 10 determines to use 1ch in the WFD connection with the terminal device 100. According to this configuration, the time that the Wi-Fi I / 20 of the MFP 10 operates on 1ch is extended, and therefore the probability that wireless communication between the MFP 10 and the first AP 6A will be successful can be improved.

[0047] At T320, the AP connection between the MFP 10 and the first AP 6A is disconnected. In this case, the MFP 10 resumes execution of the normal search process. Note that, in the state after T320, the WFD communication channel "6ch" in the channel table 46B is different from the current WFD communication channel "1ch." However, while the WFD connection is established, the WFD communication channel cannot be changed. Therefore, even if the WFD communication channel in the channel table 46B is different from the current WFD communication channel, the WFD communication channel is not changed.

[0048] At T322, an AP connection using 1ch is established between the MFP 10 and the first AP 6A. In this case, the MFP 10 saves "1ch" as the AP communication channel, maintains "6ch" for NAN communication, and maintains "1ch" as the WFD communication channel. In this case, the MFP 10 determines that the Wi-Fi I / F 20 operates on two communication channels and does not disconnect the WFD connection with the terminal device 100. Because the WFD connection is not disconnected, the user does not need to perform an operation on the MFP 10 to reconnect the WFD connection. Furthermore, because the WFD connection between the MFP 10 and the terminal device 100 is not disconnected, the user can continue to use wireless communication using the WFD connection.

[0049] (Case E; Figure 7) Case E will be described with reference to Fig. 7. The initial state of Case F is the same as the initial state of Case C in Fig. 5. Therefore, the MFP 10 sequentially executes the normal search process, the NAN search process, and the second WFD search process.

[0050] At T410, a WFD connection is established between the MFP 10 and the terminal device 100. The MFP 10 identifies the channel table 46B in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "unconnected," "unconnected," and "connected," respectively. The MFP 10 then determines that ch6 is congested. In this case, the MFP 10 identifies the communication channels "ch6" and "ch1," corresponding to the NAN communication channel and the WFD communication channel, respectively, from the channel table 46C when ch6 is congested. The MFP 10 then determines ch1 as the WFD communication channel in the process of establishing the WFD connection. The MFP 10 then maintains the NAN communication channel at "ch6" and the WFD communication channel at "ch1." In this way, when the terminal device 100 is found by the second WFD search process, the MFP 10 determines that ch1 will be used in the WFD connection with the terminal device 100. With this configuration, the MFP 10 can communicate with the terminal device 100 using an appropriate communication channel.

[0051] At T412, an AP connection using 2ch is established between the MFP 10 and the second AP 6B. In this case, the AP communication channel, the NAN communication channel, and the WFD communication channel are "2ch," "6ch," and "1ch," respectively. That is, the Wi-Fi I / F 20 operates on three communication channels. In this case, the MFP 10 executes processing for causing the Wi-Fi I / F 20 to operate on two communication channels. Specifically, the MFP 10 executes processing for disconnecting the WFD connection with the terminal device 100. Next, the MFP 10 identifies the channel table 46D in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "connected," "unconnected," and "unconnected," respectively. Next, the MFP 10 identifies the communication channels "6ch" and "6ch" corresponding to the NAN communication channel and the WFD communication channel, respectively, from the channel table 46D. Next, the MFP 10 saves "2ch" as the AP communication channel, maintains the NAN communication channel at "6ch," and sets the WFD communication channel to "6ch." In this way, the MFP 10 disconnects the WFD connection with the terminal device 100 when an AP connection with the second AP 6B is established after the WFD connection with the terminal device 100 is established and the communication channel used in the AP connection is different from the communication channel used in the WFD connection. The user is more likely to use the MFP 10 to perform communication using an AP connection than communication using a WFD connection. Therefore, it is possible to prevent the Wi-Fi I / F 20 from operating on three communication channels and to maintain a wireless connection that is more likely to be used by the user.

[0052] (Case F; Figure 8) Case F will be described with reference to Fig. 8. The initial state of case F is the same as the initial state of case C in Fig. 5. Therefore, the MFP 10 sequentially executes the normal search process, the NAN search process, and the second WFD search process.

[0053] At T510, an AP connection using 1ch is established between the MFP 10 and the first AP 6A. In this case, the MFP 10 identifies the channel table 46D in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "connected," "unconnected," and "unconnected," respectively. The MFP 10 then determines that 6ch is congested. The MFP 10 then identifies the communication channels "6ch" and "6ch," corresponding to the NAN communication channel and the WFD communication channel, respectively, from the channel table 46D. The MFP 10 then saves "1ch" as the AP communication channel, maintains the NAN communication channel at "6ch," and sets the WFD communication channel to "6ch."

[0054] At T512, a WFD connection is established between the MFP 10 and the terminal device 100. The MFP 10 identifies the channel table 46E in which the status information corresponding to the MAC addresses "MACx," "MACy," and "MACz" is "connected," "not connected," and "connected," respectively. The MFP 10 then determines that 6ch is congested. The MFP 10 then identifies the communication channels "6ch" and "APch," corresponding to the NAN communication channel and the WFD communication channel, respectively, from the channel table 46E. In this case, when establishing a WFD connection with the terminal device 100, the MFP 10 determines 6ch as the WFD communication channel. As a result, the MFP 10 maintains the AP communication channel at "1ch," maintains the NAN communication channel at "6ch," and sets the WFD communication channel to "1ch."

[0055] At T520, the AP connection between the MFP 10 and the first AP 6A is disconnected. In this case, the MFP 10 resumes the execution of the normal search process.

[0056] At T522, an AP connection using 2ch is established between the MFP 10 and the second AP 6B. Therefore, the AP communication channel, NAN communication channel, and WFD communication channel become "2ch," "6ch," and "1ch," respectively. In this case, the MFP 10 determines that the Wi-Fi I / F 20 operates on three communication channels and executes the same processing as that after T412 in FIG. 7. Specifically, the MFP 10 executes processing to disconnect the WFD connection. As a result, the MFP 10 saves "2ch" as the AP communication channel, maintains the NAN communication channel at "6ch," and sets the WFD communication channel to "6ch." This puts the Wi-Fi I / F 20 into a state where it operates on two communication channels.

[0057] (Effects of this embodiment) As described above, when an AP connection with an AP is established, the MFP 10 executes the NAN search process and the first WFD search process using the same communication channel "6ch" (Case A in FIG. 3, Case C in FIG. 5, Case D in FIG. 6, Case F in FIG. 8), and when an AP connection with an AP is not established, the MFP 10 executes the NAN search process using the communication channel "6ch" and the second WFD search process using the communication channel "1ch" (Case C in FIG. 5, Case F in FIG. 8). With this configuration, the communication channel used for the search process can be appropriately switched depending on whether an AP connection is established between the MFP 10 and the access point.

[0058] (Correspondence) The MFP 10 is an example of a "communication device." The normal Wi-Fi method is an example of a "first wireless communication method." The Wi-Fi Aware method is an example of a "second wireless communication method." The WFD method is an example of a "third wireless communication method." The Wi-Fi I / F 20 is an example of a "wireless interface." The terminal device 100 is an example of an "external device." The AP connection is an example of a "first wireless connection." The communication channel "6ch" is an example of a "first communication channel." The NAN search process is an example of a "first search process." The first WFD search process is an example of a "second search process." The communication channel "6ch" is an example of a "second communication channel." The NAN search process is an example of a "third search process." The communication channel "1ch" is an example of a "third communication channel." The second WFD search process is an example of a "fourth search process." The second WFD search process is an example of a "fifth search process." The NAN connection is an example of a “second wireless connection.” The WFD connection is an example of a “third wireless connection.”

[0059] T22 in Fig. 3 is an example of a process executed by a "first establishment unit." The process of MFP 10 after T26 in case A in Fig. 3 and the process of MFP 10 before T210 in Fig. 5 are examples of a process executed by a "search unit."

[0060] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Modifications of the above-mentioned embodiments are listed below.

[0061] (First Modification) The "communication device" is not limited to an MFP, but may be a printer with a printing function, a scanner with a scanning function, a PC, or the like.

[0062] (Second Modification) When "1ch or 11ch" is identified as the NAN communication channel or the WFD communication channel from the channel tables 46A to 46C, the MFP 10 may determine 11ch as the NAN communication channel or the WFD communication channel. In this modification, 11ch is an example of the "third communication channel."

[0063] (Third Modification) The "first communication channel" and the "second communication channel" may be different. In this modification, the SoftAP method established by the Wi-Fi Alliance is an example of the "second wireless communication method."

[0064] (Fourth Modification) The channel table 46A may include only the communication channel "6ch" as the NAN communication channel and only the communication channel "1ch or 11ch" as the WFD communication channel. In this modification, when an AP connection, a NAN connection, and a WFD connection are not established, the MFP 10 determines the communication channel "6ch" as the NAN communication channel and determines the communication channel "1ch or 11ch" as the WFD communication channel, regardless of whether 6ch is congested. In other words, when an AP connection, a NAN connection, and a WFD connection are not established, the WFD communication channel is not switched depending on whether 6ch is congested.

[0065] (Fifth Modification) In the NDP Setup in T70 of Case A in Fig. 3, the MFP 10 may determine a communication channel other than 6ch as the NAN connection channel. In this modification, the "second establishment unit" can be omitted.

[0066] (Sixth Modification) In T110 of Case B in Fig. 4, the MFP 10 may determine a communication channel other than 1ch as the NAN connection channel. In this modification, the "third establishment unit" can be omitted.

[0067] (Seventh Modification) In T112 of Case B in Fig. 4, MFP 10 may not disconnect the NAN connection even when Wi-Fi I / F 20 operates on three communication channels. In this modification, the "first disconnection unit" can be omitted. In another modification, after T112, MFP 10 may disconnect the AP connection instead of the NAN connection.

[0068] (Eighth Modification) In case D of Fig. 6, the MFP 10 may determine a communication channel different from the APch as the WFD connection channel. In this modification, the "fourth establishment unit" can be omitted.

[0069] (Ninth Modification) In T410 of Case E in Fig. 7, the MFP 10 may determine a communication channel other than 1ch as the WFD connection channel. In this modification, the "fifth establishment unit" can be omitted.

[0070] (Tenth Modification) In T412 of Case E in Fig. 7, the MFP 10 may not disconnect the WFD connection even when the Wi-Fi I / F 20 is in a state where it operates on three communication channels. In this modification, the "second disconnection unit" can be omitted. In another modification, after T412, the MFP 10 may disconnect the AP connection instead of the WFD connection.

[0071] (Eleventh Modification) In each of the above embodiments, the processes of Figures 3 to 8 are realized by software (for example, programs 40, 140, 142), but at least one of these processes may be realized by hardware such as a logic circuit.

[0072] Furthermore, the technical elements described in this specification or drawings exhibit technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings simultaneously achieve multiple objectives, and achieving one of those objectives is itself technically useful.

[0073] In the scope of the claims at the time of filing, even if each claim is dependent on only some of the claims, this does not mean that each claim can be dependent on only those some of the claims. To the extent that there is no technical contradiction, each claim can also be dependent on other claims that were not dependent on it at the time of filing. In other words, the technologies of each item can be combined in various ways as follows: (Item 1) A communication device, a wireless interface capable of communicating according to a first wireless communication method, a second wireless communication method, and a third wireless communication method; a first establishment unit that establishes a first wireless connection with an access point via the wireless interface in accordance with the first wireless communication scheme; a search unit that searches for an external device via the wireless interface; Equipped with The search unit executes a first search process using a first communication channel in accordance with the second wireless communication method and a second search process using the first communication channel in accordance with the third wireless communication method in a first situation in which the first wireless connection with the access point is established; In a second situation in which the first wireless connection with the access point is not established, a third search process is performed using a second communication channel in accordance with the second wireless communication method, and a fourth search process is performed using a third communication channel different from the second communication channel in accordance with the third wireless communication method. Communication equipment. (Item 2) Item 1. The communication device according to item 1, wherein the first communication channel and the second communication channel are the same. (Item 3) the search unit is capable of searching for the external device by using one of three predetermined communication channels in accordance with the third wireless communication scheme, 3. The communication device according to claim 1, wherein each of the second communication channel and the third communication channel is one of the three communication channels. (Item 4) The search unit In the second situation, when the second communication channel is congested, the third search process and the fourth search process are executed; 4. The communication device according to claim 1, wherein, in the second situation, when the second communication channel is not congested, the communication device executes the third search process and a fifth search process using the second communication channel in accordance with the third wireless communication method. (Item 5) the second wireless communication system is a Wi-Fi Aware system, 5. The communication device according to any one of items 1 to 4, wherein the third wireless communication method is a Wi-Fi Direct (registered trademark) method. (Item 6) 6. The communication device according to any one of items 1 to 5, wherein the communication channel used in the first wireless connection is one of 1ch to 14ch and is a channel determined by the access point. (Item 7) The communication device further comprises: a second establishment unit that, when the external device is found by the first search process, establishes a second wireless connection with the external device via the wireless interface in accordance with the second wireless communication method; 7. The communication device according to claim 1, wherein the second establishment unit uses the first communication channel in the second wireless connection. (Item 8) The communication device further comprises: a third establishment unit that, when the external device is found by the fifth search process, establishes a second wireless connection with the external device via the wireless interface in accordance with the second wireless communication method; Item 5. The communication device according to item 4, wherein the third establishment unit uses the third communication channel in the second wireless connection. (Item 9) The communication device further comprises: Item 9. The communication device described in item 8, further comprising a first disconnection unit that disconnects the second wireless connection with the external device when the first wireless connection with the access point is established after the second wireless connection with the external device is established and the communication channel used in the first wireless connection is different from the communication channel used in the second wireless connection. (Item 10) The communication device further comprises: a fourth establishment unit that, when the external device is found by the second search process, establishes a third wireless connection with the external device via the wireless interface in accordance with the third wireless communication method; 10. The communication device according to any one of claims 1 to 9, wherein the fourth establishment unit uses the same communication channel in the third wireless connection as the communication channel used in the first wireless connection. (Item 11) The communication device further comprises: a fifth establishment unit that, when the external device is found by the fourth search process, establishes a third wireless connection with the external device via the wireless interface in accordance with the third wireless communication scheme; 11. The communication device according to claim 1, wherein the fifth establishment unit uses the third communication channel in the third wireless connection. (Item 12) The communication device further comprises: Item 12. The communication device described in item 11, further comprising: a second disconnection unit that disconnects the third wireless connection with the external device when the first wireless connection with the access point is established after the third wireless connection with the external device is established and the communication channel used in the first wireless connection is different from the communication channel used in the third wireless connection. (Item 13) 1. A computer program for a communication device, comprising: The said communications prosecution is A computer, a wireless interface capable of communicating according to a first wireless communication method, a second wireless communication method, and a third wireless communication method; The computer program causes the computer to: a first establishment unit that establishes a first wireless connection with an access point via the wireless interface in accordance with the first wireless communication scheme; a search unit that searches for an external device via the wireless interface; It functions as The search unit executes a first search process using a first communication channel in accordance with the second wireless communication method and a second search process using the first communication channel in accordance with the third wireless communication method in a first situation in which the first wireless connection with the access point is established; In a second situation in which the first wireless connection with the access point is not established, a third search process is performed using a second communication channel in accordance with the second wireless communication method, and a fourth search process is performed using a third communication channel different from the second communication channel in accordance with the third wireless communication method. Computer program. (Item 14) 1. A method performed by a communication device, comprising: the communication device includes a wireless interface capable of communicating in accordance with a first wireless communication scheme, a second wireless communication scheme, and a third wireless communication scheme; The method comprises: a first establishing step of establishing a first wireless connection with an access point via the wireless interface in accordance with the first wireless communication scheme; a searching step of searching for an external device via the wireless interface; Equipped with The searching step executes a first search process using a first communication channel in accordance with the second wireless communication method and a second search process using the first communication channel in accordance with the third wireless communication method in a first situation in which the first wireless connection with the access point is established; In a second situation in which the first wireless connection with the access point is not established, a third search process is performed using a second communication channel in accordance with the second wireless communication method, and a fourth search process is performed using a third communication channel different from the second communication channel in accordance with the third wireless communication method. method. [Explanation of symbols]

[0074] 2: communication system, 6A: first access point, 6B: second access point, 10: MFP, 12: operation unit, 14: display unit, 16: print execution unit, 18: scan execution unit, 20: Wi-Fi I / F, 30: control unit, 32: CPU, 34: memory, 40: program, 42: NAN flag, 44: WFD flag, 46A: channel table, 46B: channel table, 46C: channel table, 46D: channel table, 46E: channel table, 46F: channel table, 48: WFD channel information, 100: terminal device, 112: operation unit, 114: display unit, 120: Wi-Fi I / F, 130: control unit, 132: CPU, 134: memory, 140: OS program, 142: application program

Claims

1. A communication device, a wireless interface capable of communicating according to a first wireless communication method, a second wireless communication method, and a third wireless communication method; a first establishment unit that establishes a first wireless connection with an access point via the wireless interface in accordance with the first wireless communication scheme; a search unit that searches for an external device via the wireless interface; Equipped with The search unit executes a first search process using a first communication channel in accordance with the second wireless communication method and a second search process using the first communication channel in accordance with the third wireless communication method in a first situation in which the first wireless connection with the access point is established; In a second situation in which the first wireless connection with the access point is not established, a third search process is executed using a second communication channel in accordance with the second wireless communication method, and a fourth search process is executed using a third communication channel different from the second communication channel in accordance with the third wireless communication method. Communication equipment.

2. The communication device of claim 1 , wherein the first communication channel and the second communication channel are the same.

3. the search unit is capable of searching for the external device by using any one of three predetermined communication channels in accordance with the third wireless communication system, 2. The communication device according to claim 1, wherein each of the second communication channel and the third communication channel is one of the three communication channels.

4. The search unit In the second situation, when the second communication channel is congested, the third search process and the fourth search process are executed; 2. The communication device according to claim 1, wherein, in the second situation, when the second communication channel is not congested, the third search process and a fifth search process using the second communication channel in accordance with the third wireless communication method are executed.

5. the second wireless communication method is a Wi-Fi Aware method, The communication device according to claim 1 , wherein the third wireless communication method is a Wi-Fi Direct (registered trademark) method.

6. 2. The communication device according to claim 1, wherein the communication channel used in the first wireless connection is one of 1ch to 14ch and is a channel determined by the access point.

7. The communication device further comprises: a second establishment unit that establishes a second wireless connection with the external device via the wireless interface in accordance with the second wireless communication method when the external device is found by the first search process; The communication device according to claim 1 , wherein the second establishment unit uses the first communication channel in the second wireless connection.

8. The communication device further comprises: a third establishment unit that, when the external device is found by the fifth search process, establishes a second wireless connection with the external device via the wireless interface in accordance with the second wireless communication method; The communication device according to claim 4 , wherein the third establishment unit uses the third communication channel in the second wireless connection.

9. The communication device further comprises:

9. The communication device according to claim 8, further comprising: a first disconnection unit that disconnects the second wireless connection with the external device when the first wireless connection with the access point is established after the second wireless connection with the external device is established and a communication channel used in the first wireless connection is different from a communication channel used in the second wireless connection.

10. The communication device further comprises: a fourth establishment unit that, when the external device is found by the second search process, establishes a third wireless connection with the external device via the wireless interface in accordance with the third wireless communication method; The communication device according to claim 1 , wherein the fourth establishment unit uses, in the third wireless connection, the same communication channel as that used in the first wireless connection.

11. The communication device further comprises: a fifth establishment unit that, when the external device is found by the fourth search process, establishes a third wireless connection with the external device via the wireless interface in accordance with the third wireless communication method; The communication device according to claim 1 , wherein the fifth establishment unit uses the third communication channel in the third wireless connection.

12. The communication device further comprises:

12. The communication device according to claim 11, further comprising: a second disconnection unit that disconnects the third wireless connection with the external device when the first wireless connection with the access point is established after the third wireless connection with the external device is established and a communication channel used in the first wireless connection is different from a communication channel used in the third wireless connection.

13. 1. A computer program for a communication device, comprising: The communication device A computer, a wireless interface capable of communicating according to a first wireless communication method, a second wireless communication method, and a third wireless communication method; The computer program causes the computer to: a first establishment unit that establishes a first wireless connection with an access point via the wireless interface in accordance with the first wireless communication scheme; a search unit that searches for an external device via the wireless interface; It functions as The search unit executes a first search process using a first communication channel in accordance with the second wireless communication method and a second search process using the first communication channel in accordance with the third wireless communication method in a first situation in which the first wireless connection with the access point is established; In a second situation in which the first wireless connection with the access point is not established, a third search process is executed using a second communication channel in accordance with the second wireless communication method, and a fourth search process is executed using a third communication channel different from the second communication channel in accordance with the third wireless communication method. Computer program.

14. 1. A method performed by a communication device, comprising: the communication device includes a wireless interface capable of communicating in accordance with a first wireless communication method, a second wireless communication method, and a third wireless communication method; The method comprises: a first establishing step of establishing a first wireless connection with an access point via the wireless interface in accordance with the first wireless communication scheme; a searching step of searching for an external device via the wireless interface; Equipped with The searching step executes a first search process using a first communication channel in accordance with the second wireless communication method and a second search process using the first communication channel in accordance with the third wireless communication method in a first situation in which the first wireless connection with the access point is established; In a second situation in which the first wireless connection with the access point is not established, a third search process is executed using a second communication channel in accordance with the second wireless communication method, and a fourth search process is executed using a third communication channel different from the second communication channel in accordance with the third wireless communication method. method.

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