阅读说明：本技术 电子设备以及通信控制方法 (Electronic device and communication control method ) 是由 小泉纯平 于 2021-03-23 设计创作，主要内容包括：本发明提供一种根据工作模式而执行接入点的扫描处理的电子设备以及通信控制方法等。电子设备(200)包括：无线通信部(220),其实施经由外部的接入点(AP)的无线通信；处理部(210),其以包括第一工作模式和与第一工作模式相比而功率消耗较少的第二工作模式在内的多个工作模式中的任意一个工作模式进行工作,并对无线通信部(220)进行控制。处理部(210)在工作模式为第一工作模式的情况下,作为接入点(AP)的扫描处理而执行第一扫描处理,且在工作模式为第二工作模式的情况下,执行与第一扫描处理相比而对扫描对象进行了限制的第二扫描处理。(The invention provides an electronic device and a communication control method for executing scanning processing of an access point according to an operation mode. An electronic device (200) includes: a wireless communication unit (220) that performs wireless communication via an external Access Point (AP); and a processing unit (210) that controls the wireless communication unit (220) by operating in any one of a plurality of operation modes including a first operation mode and a second operation mode that consumes less power than the first operation mode. A processing unit (210) executes a first scanning process as a scanning process of an Access Point (AP) when the operation mode is a first operation mode, and executes a second scanning process that restricts a scanning target compared to the first scanning process when the operation mode is a second operation mode.)

1. An electronic device, comprising:

a wireless communication unit that performs wireless communication via an external access point;

a processing unit that operates in any one of a plurality of operation modes including a first operation mode and a second operation mode that consumes less power than the first operation mode, and controls the wireless communication unit,

the processing unit executes a first scanning process as a scanning process of the access point when the operation mode is the first operation mode, and executes a second scanning process in which a scanning target is restricted from the first scanning process when the operation mode is the second operation mode.

2. The electronic device of claim 1,

the second scanning process is a process in which, with respect to the first scanning process, at least one of a first limit to limit the scanning target service set identifier to a service set identifier having a connection history, a second limit to limit the scanning target channel to a predetermined channel, and a third limit to limit the number of scanning target service set identifiers to a predetermined threshold value or less is applied.

3. The electronic device of claim 1 or 2,

the plurality of operating modes including a third operating mode that consumes less power than the first operating mode and more power than the second operating mode,

the processing unit executes a third scanning process in which the limitation content of the scanning target is different from both the first scanning process and the second scanning process when the operation mode is the third operation mode.

4. The electronic device of claim 2,

the plurality of operating modes including a third operating mode that consumes less power than the first operating mode and more power than the second operating mode,

the processing unit executes a third scanning process in which the first limitation is applied to the first scanning process and the second limitation and the third limitation are not applied when the operation mode is the third operation mode, and executes the third scanning process

When the operation mode is the second operation mode, the second scanning process is executed in which two or more of the first limit, the second limit, and the third limit are applied to the first scanning process.

5. The electronic device of claim 1,

the processing unit executes the second scanning process when the operation mode is the second operation mode and when a reception intensity of a beacon signal from the access point connected thereto is equal to or lower than a predetermined threshold value or when the beacon signal is in a non-reception state.

6. The electronic device of claim 1,

the processing unit shifts to the first operation mode and executes the first scanning process when the operation mode is the second operation mode and a communication setting change is performed in accordance with a user instruction.

7. The electronic device of claim 1,

the processing unit shifts to the first operation mode and executes the first scanning process when the access point to be connected is not searched for by the second scanning process.

8. A communication control method in an electronic device that operates in any one of a plurality of operation modes including a first operation mode and a second operation mode that consumes less power than the first operation mode and that performs wireless communication with an external access point, wherein, in the communication control method,

performing a first scanning process as a scanning process of the access point in a case where the operation mode is the first operation mode, and

when the operation mode is the second operation mode, a second scanning process in which a scanning target is limited compared to the first scanning process is executed.

Technical Field

The present invention relates to an electronic device, a communication control method, and the like.

Background

There is known an apparatus for performing a scanning process for searching for a device to be connected in wireless communication. For example, the scanning process in wireless communication according to the Wi-Fi method is scanning of an SSID (Service Set Identifier).

Patent document 1 discloses a method for shortening the time for an extension set to enter a reception mode by applying limited scanning. Patent document 2 discloses a method of scanning a base station based on an SSID search priority list formed based on a connection history. Patent document 2 also discloses a method in which a user sets the number of SSIDs stored.

In the conventional methods such as patent document 1 and patent document 2, the operation mode of the electronic device is not considered. Specifically, in an electronic device including an operation mode in which power consumption is large and an operation mode in which power consumption is small, a desired scanning process differs depending on the operation mode. Therefore, in the conventional method, it becomes difficult to appropriately scan the connection target while maintaining the power saving state, for example.

Patent document 1: japanese laid-open patent publication No. 8-265823

Patent document 2: japanese patent laid-open publication No. 2004-343458

Disclosure of Invention

One embodiment of the present disclosure relates to an electronic device including: a wireless communication unit that performs wireless communication via an external access point; and a processing unit that controls the wireless communication unit to operate in any one of a plurality of operation modes including a first operation mode and a second operation mode that consumes less power than the first operation mode, wherein when the operation mode is the first operation mode, the processing unit executes a first scanning process as a scanning process of the access point, and when the operation mode is the second operation mode, the processing unit executes a second scanning process that limits a scanning target than the first scanning process.

Another aspect of the present disclosure relates to a communication control method in an electronic device that operates in any one of a plurality of operation modes including a first operation mode and a second operation mode that consumes less power than the first operation mode and performs wireless communication with an external access point, wherein, when the operation mode is the first operation mode, a first scanning process is executed as a scanning process of the access point, and when the operation mode is the second operation mode, a second scanning process that restricts a scanning target than the first scanning process is executed.

Drawings

Fig. 1 is a diagram illustrating connection between an electronic device and an access point.

Fig. 2 is a configuration example of the electronic apparatus.

Fig. 3 is a detailed configuration example of the processing unit and the wireless communication unit.

Fig. 4 is an example of a screen displaying the result of the scanning process.

Fig. 5 is a graph showing a relationship between a processing load in the full scan and a processing capacity of the processing unit.

Fig. 6 is a graph showing a relationship between the processing load in the full scan and the processing load in the limit scan.

Fig. 7 is a flowchart for explaining the flow of processing including the scanning processing.

Fig. 8 is a flowchart illustrating limited scanning.

Fig. 9 is a flowchart for explaining the flow of processing including the scanning processing.

Fig. 10 shows an example of the relationship between the operation mode and the restriction content.

Detailed Description

The present embodiment will be described below. The present embodiment described below is not intended to unduly limit the scope of the claims. It should be noted that not all of the structures described in the present embodiment are necessarily essential structural elements.

1. System architecture

Fig. 1 is a diagram schematically showing an example of the system configuration of the present embodiment. As shown in fig. 1, the electronic apparatus 200 of the present embodiment is connected to the access point AP. The access point AP is, for example, a wireless router having a router function.

The electronic apparatus 200 is, for example, a printer. Alternatively, the electronic apparatus 200 may be a scanner, a facsimile device, or a copying machine. The electronic apparatus 200 may be a multi-function Peripheral (MFP) having a plurality of functions, and a multi-function Peripheral having a printing function is also an example of a printer. Alternatively, the electronic device 200 may be a projector, a head-mounted display device, a wearable device, a biological information measuring device, an automatic device, a video device, a portable information terminal, a physical quantity measuring device, or the like. The biological information measuring device is a pulse meter, a pedometer, an activity meter, or the like. The imaging device is a camera or the like. The portable information terminal is a smart phone, a portable game machine, or the like.

The electronic apparatus 200 performs communication implemented by wireless with the external access point AP. Here, the wireless communication is communication using a Wi-Fi system. The Wi-Fi system is based on the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard and wireless communication system based on the standard.

Fig. 2 is a block diagram showing an example of the structure of the electronic apparatus 200. In addition, fig. 2 shows an electronic device 200 having a printing function, and in the following description, an example in which the electronic device 200 is a printer will be also described as appropriate. However, the electronic apparatus 200 can be extended to a point other than the printer as described above. The electronic apparatus 200 includes a processing unit 210, a wireless communication unit 220, a display unit 230, an operation unit 240, a printing unit 250, and a storage unit 260.

The processing unit 210 controls each part of the electronic apparatus 200. The electronic device 200 includes, for example, a wireless communication unit 220, a storage unit 260, and a printing unit 250. The processing unit 210 is specifically a processor or a controller. For example, the processing unit 210 may include a plurality of CPUs such as a main CPU and a sub-CPU. The main CPU performs control of each part of the electronic apparatus 200 and overall control. The sub CPU is, for example, a CPU that performs communication control of the wireless communication unit 220. Alternatively, when the electronic device 200 is a printer, a CPU for executing various processes for printing may be further provided.

The processing unit 210 of the present embodiment can be configured by hardware described below. The hardware may include at least one of a circuit that processes a digital signal and a circuit that processes an analog signal. For example, the hardware can be configured by one or more circuit devices and one or more circuit elements mounted on a circuit substrate. The one or more Circuit devices are, for example, an IC (Integrated Circuit), an FPGA (field-programmable gate array), or the like. The one or more circuit elements are for example resistors, capacitors, etc.

The processing unit 210 can be realized by a processor described below. The electronic device 200 of the present embodiment includes a memory that stores information, and a processor that operates based on the information stored in the memory. The information is, for example, a program and various data. The processor includes hardware. The Processor may be a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), or other various processors. The Memory may be a semiconductor Memory such as an SRAM (Static Random Access Memory) or a DRAM (Dynamic Random Access Memory), a register, a magnetic storage device such as a hard disk device, or an optical storage device such as an optical disk device. For example, the memory stores a command that can be read by a computer, and the command is executed by the processor, so that the function of the processing section 210 is realized as processing. The command here may be a command constituting a command set of a program or a command instructing a hardware circuit of the processor to operate. All or a part of the processing unit 210 may be realized by cloud computing.

The wireless communication section 220 is realized by at least one wireless communication device. The wireless communication device is also referred to as a wireless communication chip. The wireless communication device herein includes a wireless communication device that performs wireless communication according to the Wi-Fi standard. However, the wireless communication unit 220 may include a wireless communication device that performs wireless communication according to a standard other than the Wi-Fi standard. The standard other than the Wi-Fi standard may be, for example, Bluetooth (registered trademark), and in a narrow sense, BLE (Bluetooth Low Energy).

The display unit 230 is configured by a display or the like that displays various information to the user. The operation unit 240 is configured by buttons and the like that receive input operations from a user. The display unit 230 and the operation unit 240 may be integrally configured by a touch panel, for example.

The printing section 250 includes a print engine. The print engine is a mechanical structure that performs printing of an image on a print medium. The print engine includes, for example, a transport mechanism, an ink jet type discharge head, a drive mechanism of a carriage including the discharge head, and the like. The print engine prints an image on a print medium by ejecting ink from an ejection head onto the print medium conveyed by the conveyance mechanism. The printing medium may be paper, cloth, or other medium. The specific configuration of the print engine is not limited to the configuration illustrated here, and may be a configuration in which printing is performed by toner in an electrophotographic manner.

The storage unit 260 stores various information such as data and programs. The processing unit 210 and the wireless communication unit 220 operate with the storage unit 260 as an operation area, for example. The storage unit 260 may be a semiconductor memory such as an SRAM or a DRAM, a register, a magnetic storage device, or an optical storage device. The storage unit 260 may store data transmitted from an information processing apparatus connected to the access point AP by wireless communication. The data here is, for example, data used for printing by the printing unit 250.

Fig. 3 is a diagram showing a specific configuration example of the processing unit 210 and the wireless communication unit 220 in the electronic device 200. As described above, the wireless communication unit 220 may be implemented by a wireless communication chip, specifically, a Wi-Fi chip 221 that performs wireless communication by a Wi-Fi method. The processing unit 210 is a processor, for example, a CPU 211.

The CPU211 includes, for example, a driver 212 that implements drive control of the Wi-Fi chip 221, and an application 213. For example, the storage unit 260 stores driver software for controlling the Wi-Fi chip 221 and application software for executing processing related to wireless communication.

The CPU211 loads driver software from the storage unit 260 and operates in accordance with the driver software, thereby controlling the Wi-Fi chip 221. The CPU211 loads application software from the storage unit 260 and operates in accordance with the application software, thereby performing processing related to wireless communication. The driver 212 in fig. 3 indicates that control of the Wi-Fi chip 221 is implemented by, for example, a part of the CPU211 operating in accordance with driver software. Similarly, the application program 213 in fig. 3 indicates that the CPU211 operates partially in accordance with application software to perform input/output with the driver 212 and processing of information from the driver 212.

The processing unit 210 of the electronic apparatus 200 may include a processor different from the CPU211 shown in fig. 3. For example, the CPU211 is a sub-CPU for communication. The processing unit 210 may further include a main CPU that controls the entire electronic device 200, such as print control and power saving control. In this case, the CPU211 performs control of the driver 212 based on an instruction of a main CPU, not shown. The CPU211 operates in an operation mode determined by the main CPU.

The Wi-Fi chip 221 acquires information from the access point AP and outputs the acquired information to the driver 212. For example, in SSID scanning for searching for access points AP existing around, the Wi-Fi chip 221 receives a beacon signal according to the Wi-Fi standard from the access points AP and outputs the received beacon signal to the driver 212.

The driver 212 converts the information contained in the beacon signal into a form that can be processed by the application 213 based on the signal received from the Wi-Fi chip 221, and holds it as list information. Then, the driver 212 transmits the list information to the application 213 when the scan processing of the SSID is ended. In the normal scanning process, for example, the Wi-Fi chip 221 performs a process of receiving beacon signals for all channels while sequentially changing the channels, according to the control of the driver 212. Hereinafter, the scanning process of the SSID without particularly setting a limitation is described as full scanning.

The channel in Wi-Fi wireless communication includes, for example, a channel in a 2.4GHz band and a channel in a 5GHz band. The 2.4GHz band channel includes 1ch, 2ch, …, and 14 ch. The channels of the 5GHz band comprise 36ch of the 5.2GHz band, 40ch, 44ch, 48ch, 52ch of the 5.3GHz band, 56ch, 60ch, 64ch, 100ch of the 5.6GHz band, 104ch, …, 140ch, 149ch, 153ch, …, 165ch of the 5.8GHz band.

In the full scan, the scanning process is sequentially performed for all the channels described above. In addition, the use of a predetermined channel is prohibited by law according to countries or regions. Therefore, the scan process can be omitted for the channels whose use is prohibited.

Further, since there is no limitation on the SSID and the like in the full scan, when the Wi-Fi chip 221 receives a beacon signal, the driver 212 performs processing such as format conversion for the beacon signal and adds the processing result to the list information.

The beacon signal according to the Wi-Fi method includes information related to the security standard and various support information in addition to the SSID of the access point AP. The security standards include, for example, WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access), WPA2(Wi-Fi Protected Access 2), WPA3(Wi-Fi Protected Access3), and the like. The security standard may include information related to an encryption scheme. The Encryption method includes TKIP (Temporal Key Integrity Protocol), AES (Advanced Encryption Standard), and the like. The support information includes information of which one of the standards of IEEE 802.11 is supported, for example. Among the IEEE 802.11 standards, 802.11a, 802.11b, 802.11n, 802.11ac, and the like are included. The beacon signal also includes information indicating a beacon transmission interval, channel information, and the like.

When the scanning of all channels is completed, the driver 212 transmits the created list information to the application 213. The application 213 performs processing based on the list information. For example, the application 213 performs a process of displaying the SSID list screen shown in fig. 4 on the display unit 230. As shown in fig. 4, the SSID list screen is a screen for displaying SSIDs searched for by the scanning process. The SSID list screen may also include other information such as radio wave intensity, for example. The SSID list screen may be displayed on a device different from the electronic apparatus 200.

The application 213 performs processing for accepting an operation of selecting an SSID by a user and connecting to an access point AP corresponding to the selected SSID. Specifically, the application 213 instructs the driver 212 of connection to the selected access point AP. The driver 212 controls the Wi-Fi chip 221 to execute routines necessary for connection establishment, such as transmission and reception of Authentication, transmission of Association Request, and reception of Association Response.

Fig. 5 is a diagram showing a relationship between a processing load and a processing capability of the electronic device 200 when the full scan is performed. The horizontal axis of fig. 5 represents time, and the vertical axis represents processing load or processing capacity. In the full scan, all beacon signals received using a predetermined channel are to be processed, and it is necessary to sequentially scan a large number of channels. As described above, the beacon signal of Wi-Fi includes a variety of information. Further, in an office or the like, there may be a large number of access points AP around the electronic apparatus 200. When performing full scan, the driver 212 needs to process a large number of beacon signals, which results in a large processing load.

When the processing unit 210 of the electronic device 200 operates in the normal operation mode, which is an operation mode in which power consumption is large, the processing unit 210 including the driver 212 has a high processing capability as shown in fig. 5. Therefore, the full scan can be performed. On the other hand, when the processing unit 210 operates in the power saving mode, which is an operation mode with low power consumption, the processing capability is degraded as shown in fig. 5. Therefore, the processing load of the scanning process exceeds the processing capacity of the processing section 210. In this state, since appropriate scan processing cannot be executed, it is necessary to shift to an operation mode that consumes much power. As a result, since the period during which the power consumption is large becomes long, the power saving effect is deteriorated by changing the operation mode. More specifically, the operation mode with high power consumption is a mode in which the frequency of the clock signal for driving the processing unit 210 is high, and the operation mode with low power consumption is a mode in which the frequency of the clock signal is low.

The electronic apparatus 200 is, for example, a printer. The printer is less necessary to operate at high speed, except for the case of performing printing, the case of performing an operation by the user, and the like. Therefore, printers that have a plurality of operation modes with different power consumption and shift to a power saving mode with less power consumption based on a predetermined condition are widely used. However, the scan processing of the SSID may be performed in the power saving mode. In this case, the meaning of setting the power saving mode is reduced each time the normal operation mode is shifted. On the other hand, if the limited scan process with a low processing load can be executed, the scan process can be performed also in the power saving mode. However, since the SSID to be searched is restricted during the restricted scan, there is a possibility that the access point AP to be connected cannot be found unless the scan is executed according to the situation. In the conventional method such as patent document 1, there is no disclosure of a method of performing the scanning process in consideration of the operation mode of the electronic apparatus 200.

The electronic device 200 of the present embodiment includes the wireless communication unit 220 and the processing unit 210 as described above. The wireless communication unit 220 performs wireless communication via the external access point AP. The processing unit 210 operates in any one of a plurality of operation modes including a first operation mode and a second operation mode that consumes less power than the first operation mode. The processing unit 210 controls the wireless communication unit 220.

The first operation mode here is, for example, a normal operation mode in which the frequency of the clock signal is high. The second operation mode is a power saving mode in which the frequency of the clock signal is low. As a modification, three or more operation modes may be used. For example, the power saving modes may include a first power saving mode and a second power saving mode.

When the operation mode is the first operation mode, the processing unit 210 executes the first scanning process as the scanning process of the access point AP. Further, when the operation mode is the second operation mode, the processing unit 210 executes the second scanning process in which the scanning target is restricted from the first scanning process. The first scanning process is, for example, full scanning. The second scanning process is a limit scan in which the scanning object is limited compared to the full scan. However, the method according to the present embodiment is not limited to the first scanning process as long as there is a difference in the scanning target between the first scanning process and the second scanning process.

Fig. 6 is a diagram showing a processing load when the limited scan is performed. For example, as described later, by limiting the SSID to be searched or limiting the upper limit number of SSIDs, the processing load per channel can be reduced. As a result, even in the power saving mode in which the processing capability of the processing section 210 is low, the appropriate scan processing can be executed. The limitation of the scanning target may be a limitation of a channel as described later. When the search channel is restricted and the SSID is not restricted, the processing load per channel is not reduced, and therefore the load exceeding the capacity of the processing unit 210 may be temporarily borne. However, since the processing load does not continuously exceed the processing capacity as in the case of the full scan, the appropriate scan processing can be executed also in this case.

The processing performed by the electronic device 200 according to the present embodiment may be implemented as a communication control method. The communication control method according to the present embodiment is a communication control method in an electronic apparatus 200 that performs wireless communication with an external access point AP while operating the electronic apparatus 200 in any one of a plurality of operation modes including a first operation mode and a second operation mode that consumes less power than the first operation mode. In the communication control method, when the operation mode is the first operation mode, the first scanning process is executed as the scanning process of the access point AP, and when the operation mode is the second operation mode, the second scanning process in which the scanning target is restricted from the first scanning process is executed.

2. Flow of treatment

The flow of the processing of the present embodiment will be described. Hereinafter, an example will be described in which the first operation mode is the normal operation mode and the second operation mode is the power saving mode. Further, an example in which the first scanning process is full scanning will be described. The second scanning process is the limit scanning as described above.

Two factors are considered as triggers for the occurrence of the scanning process. The first trigger is that the electronic device 200 connected so far is disconnected from the access point AP. The second trigger is an operation performed by the user to change the wireless communication setting of the electronic apparatus 200 and connect to the access point AP.

A temporary link down or roaming is considered as a main reason for the occurrence of the first trigger. The temporary link disconnection may be, for example, a case where at least one of the access point AP and the wireless communication unit 220 of the electronic device 200 temporarily becomes unstable due to some main cause, a case where a radio wave condition around the access point AP or the electronic device 200 temporarily changes, or the like. In this case, the user is expected to have a high possibility of maintaining the connection with the access point AP to which the user has been connected. Therefore, it is effective to try reconnection with the access point AP using the connection information of the access point AP which has been connected. Here, the connection information is information used for connection, and examples thereof include an SSID and a password.

Furthermore, roaming is an alternation between multiple access points AP. For example, in an office or the like, the same SSID is assigned to a plurality of access points AP disposed at different positions in advance. Consider a case where the electronic device 200 is moved from the vicinity of a first access point to the vicinity of a second access point. It is generally considered that as the radio wave intensity becomes stronger, stable communication can be achieved, and the access point AP suitable for wireless communication in the electronic apparatus 200 changes from the first access point to the second access point. In this case, as described above, by sharing the connection information among the plurality of access points AP in advance, it is possible to perform switching of the access points AP without accepting an input operation of the connection information or the like. In this case, it is also effective to try reconnection using the connection information of the access point AP that has been connected. Although the access point AP to be connected changes during roaming, the existing connection information can be disconnected from the temporary link in the same manner as the reconnection.

The second trigger corresponds to, for example, a case where the user performs a display operation of the SSID list screen shown in fig. 4. At this time, information with which access point AP the user desires to connect is unknown to the electronic apparatus 200. Therefore, it is difficult to limit the scanning target in advance, and the electronic apparatus 200 has a high necessity to perform the full scan. For example, the electronic device 200 performs a process of displaying an SSID list screen as a result of the full scan and accepting a selection operation by the user.

As described above, in the case where the second trigger occurs, the electronic apparatus 200 has a high necessity of performing the full scan. On the other hand, when the first trigger occurs, there is a possibility that a desired access point AP can be searched even during the restricted scanning. Thus, the electronic device 200 switches the processing based on the content of the trigger that has occurred and the current operating mode.

First, when the operation mode of the processing unit 210 is the first operation mode, the full scan can be performed as shown in fig. 5. Therefore, the processing section 210 executes the full scan regardless of which of the first trigger and the second trigger the trigger of the scan process is.

Fig. 7 is a flowchart illustrating a process in the case where the first trigger occurs in the second operation mode. Specifically, the processing unit 210 determines that the first trigger has occurred when the reception intensity of the beacon signal from the access point AP to which the communication is connected is equal to or less than a predetermined threshold value or when the beacon signal is in a non-reception state (step S101).

The radio wave intensity here is specifically RSSI (Received Signal Strength Indication) of the beacon Signal. Although the beacon signal is transmitted from the access point AP at a predetermined cycle, the wireless communication unit 220 may fail to receive the beacon signal for some reason even if the connection state is normal. Therefore, the beacon signal in the non-reception state here specifically means a state in which the beacon signal cannot be received continuously for a predetermined period. Various modifications can be made to the predetermined period, but the time is, for example, about 500 msec. When determining that the first trigger has occurred, the processing unit 210 executes the limited scan while maintaining the second operation mode (step S102).

The second scanning process in the present embodiment is a process in which, in comparison with the first scanning process, at least one of a first restriction that limits the scan-target SSID to an SSID having a connection history, a second restriction that limits the scan-target channel to a predetermined channel, and a third restriction that limits the number of scan-target SSIDs to a predetermined threshold value or less is applied. By providing such a limitation, the load of the second scanning process, which is the limitation scanning, can be reduced as compared with the first scanning.

Fig. 8 is a flowchart for explaining the processing in the limit scan. First, the processing unit 210 sets a channel to be searched (step S201). For example, the processing unit 210 sets a channel used for wireless communication with the access point AP connected to the previous time as a channel to be searched. The process of step S201 corresponds to the second restriction described above. By limiting the channel, the number of times the processing in step S202 and thereafter is executed can be reduced, and thus the processing load can be reduced. The channel to be searched here is not limited to the channel just before, and may include two or more channels used in the past wireless connection.

Next, the processing unit 210 performs a process of receiving a beacon signal from the access point AP using the set channel (step S202). Specifically, the Wi-Fi chip 221 receives a beacon signal, and the driver 212 acquires the beacon signal. When a plurality of beacon signals are received on one channel, the processing in steps S203 to S205 is sequentially executed for each beacon signal.

The processing unit 210 refers to the SSID portion in the beacon signal acquired in step S202, and determines whether or not the SSID is a target SSID for search (step S203). Specifically, the processing unit 210 determines whether or not the SSID included in the beacon signal matches the SSID of the access point AP to which the beacon signal has been connected.

When the SSID of the beacon signal is the SSID targeted for searching (yes at step S203), the processing unit 210 determines whether the number of pieces of information added to the list information is less than a predetermined threshold value (step S204). The threshold value here is, for example, 10, and various modifications can be made to specific values. When the number of pieces of information added to the list information reaches the threshold value, the processing unit 210 determines no in step S204.

If both of step S203 and step S204 are yes, the driver 212 performs processing such as format conversion for the received beacon signal, and adds the processing result to the list information (step S205). On the other hand, if at least one of step S203 and step S204 is "no", the driver 212 omits the processing of step S205. That is, the driver 212 omits further processing of the received beacon signal and discards the information of the beacon signal.

The process of step S203 corresponds to the first restriction. When the first restriction is applied, the beacon signal to be added to the list information is limited to a beacon signal including a specific SSID. Since the beacon signal to be added to the list information can be greatly limited, the processing load can be reduced. In addition, since the determination of step S203 can be performed by reading only the SSID portion in the beacon signal, the load in this processing does not become a big problem.

Further, the process of step S204 corresponds to the third restriction. When the third restriction is applied, if information of a certain number of beacon signals is added, the subsequent processing for the beacon signals can be omitted. Therefore, the load of the scanning process can be reduced.

In fig. 8, a process in which the wireless communication unit 220 performs passive scanning is assumed as an example (steps S202 to S204). That is, the wireless communication unit 220 waits for reception of a beacon signal from the access point AP. However, the wireless communication unit 220 may perform active scanning. The active scanning is a process of transmitting a Probe Request and receiving a Probe Response from the access point AP. In this case, the first restriction is implemented by specifying a predetermined SSID and transmitting a Probe Request. Since the Probe Response does not reply from the access point AP having a different SSID, the SSID of the scanning target can be restricted. Further, the third restriction can be achieved by not performing transmission of the Probe Request when the information added to the list information exceeds a predetermined number. However, when performing active scanning, it is necessary to transmit radio waves from the electronic device 200. Since there may be channels that cannot be used by law depending on countries or regions, passive scanning is more advantageous from the viewpoint of suppressing radio wave transmission of such channels.

Next, the processing unit 210 determines whether or not scanning has been completed on all channels to be searched (step S206). If yes in step S206, the processing unit 210 ends the limited scan process. Specifically, the driver 212 outputs the list information at the time point to the application 213. Note that, when the number of channels to be searched is limited to one by the second limitation, the determination in step S206 is inevitably yes, and therefore, this process may be omitted.

When two or more channels are set as the search target and there are channels that have not been searched for (no in step S206), the processing unit 210 changes the channel of the Wi-Fi chip 221 to any one of the channels that have not been searched for (step S207), returns to step S202, and continues the processing.

The description is continued with reference to fig. 7. After restricting the execution of the scan, the processing unit 210 determines whether or not the SSID to be searched is found (step S103). The SSID of the search target is the SSID used in the determination of step S203. For example, the processing in step S103 is determination processing of whether or not the list information is empty.

When the SSID to be searched is found, the processing unit 210 ends the processing. After the processing shown in fig. 7, for example, the processing unit 210 performs processing for automatically connecting the searched SSIDs. If the SSID to be searched is not found, the processing unit 210 shifts to the normal operation mode (step S104). After the transition to the normal operation mode, the processing unit 210 executes the full scan (step S105).

As shown in fig. 7, the processing unit 210 executes the second scanning process when the operation mode is the second operation mode and the reception intensity of the beacon signal from the connected access point AP is equal to or less than the predetermined threshold value, or when the beacon signal is in the non-reception state. In other words, the processing section 210 executes the limit scan based on the first trigger. As described above, the first trigger has a possibility of being able to follow the connection information used in the connection so far. Since there is a possibility that a desired access point AP can be connected even in the limited scan, it is significant to perform the limited scan. This can suppress the transition to the first operation mode when it is unnecessary, and thus can reduce the power consumption of the electronic apparatus 200.

As shown in steps S104 and S105, the processing unit 210 may shift to the first operation mode and execute the first scanning process when the access point AP to be connected is not searched for by the second scanning process. In a case where the electronic apparatus 200 is not connected to any one of the access points AP, the process via the network cannot be performed. For example, the electronic device 200 as a printer cannot receive a print job from a terminal device connected to the same access point AP. The print job is information including image information and print setting information to be printed. The print setting information is information for specifying set values for setting items such as paper size, single-sided/double-sided, color/monochrome, and the like.

In the case where the original access point AP or the roaming alternative access point AP is not found by the limited scanning, it is useful to search for another access point AP that can be connected. For example, by presenting a list of SSIDs searched for by the full scan, user convenience can be improved.

Fig. 9 is a flowchart illustrating a process in the case where the second trigger occurs in the second operation mode. Specifically, when the communication setting change operation by the user is accepted, the processing unit 210 determines that the second trigger has occurred (step S301). The communication setting here is specifically a setting of wireless communication, and includes at least a setting of an access point AP of a connection target. The communication setting may include information different from the information for specifying the access point AP, such as setting relating to a security standard, an encryption standard, and the like.

As described above, at the time of occurrence of the second trigger, it is difficult to infer to which access point AP the user desires to connect, and thus the scan target cannot be restricted. Therefore, the processing unit 210 shifts to the normal operation mode (step S302), and after shifting to the normal operation mode, performs the full scan (step S303).

That is, when the operation mode is the second operation mode and the communication setting change is performed according to the user instruction, the processing unit 210 shifts to the first operation mode and executes the first scanning process. If this method is adopted, it is possible to change the operation mode and perform the scanning process appropriately when the necessity of searching for a wide range of access points AP is high.

It is also assumed that, when the operation of changing the communication setting is performed using the operation unit 240 of the electronic apparatus 200, the operation mode of the processing unit 210 shifts to the first operation mode based on the previous user operation. The user operation before the communication setting changing operation is, for example, a return operation from the power saving mode, a setting item selecting operation, or the like. In this case, since the first operation mode is set when the second trigger occurs, the full scan can be performed without switching the operation mode.

The case where the communication setting change is performed in response to the instruction of the user in the second operation mode is a case where the setting change of the electronic apparatus 200 is performed using a terminal device different from the electronic apparatus 200, for example. For example, in a state where the electronic apparatus 200 and the terminal device are connected to the same access point AP, or a state where the electronic apparatus 200 and the terminal device are directly connected, the user performs an operation for connecting the electronic apparatus 200 to another access point AP using the terminal device. In this case, since the operation unit 240 of the electronic device 200 is not operated, if another job such as a print job is not performed, the operation mode of the processing unit 210 is maintained in the second operation mode.

3. Modification example

In the above, an example in which the operation mode is two modes of the first operation mode and the second operation mode is explained. The first operation mode is, for example, a normal operation mode, and the second operation mode is a power saving mode. However, the number of operation modes may be three or more.

For example, the operation modes of the present embodiment may include a third operation mode in which power consumption is smaller than in the first operation mode and power consumption is larger than in the second operation mode. The third operating mode is a first power saving mode, and the second operating mode is a second power saving mode. When the operation mode is the third operation mode, the processing unit 210 executes a third scanning process in which the content of the restriction on the scanning target is different from both the first scanning process and the second scanning process. For example, when the frequencies of the clock signals are compared, the first operation mode has a higher frequency than the third operation mode, and the third operation mode has a higher frequency than the second operation mode.

For example, when the operation mode is the third operation mode, the processing unit 210 may execute the third scanning process in which the first limitation is applied to the first scanning process and the second limitation and the third limitation are not applied. That is, the processing unit 210 restricts the SSID to be searched to the SSID having the connection history, or in a narrow sense, the SSID of the access point AP to which the terminal connection is made. On the other hand, the processing unit 210 sets all channels as search targets, and does not set an upper limit to the number of SSIDs held in the list information.

As described above, roaming is included in the condition that the limited scan is valid. In addition, a plurality of access points APs installed in an environment where roaming is performed may use different channels although the SSID is common. Therefore, even in a situation where roaming is possible, if the second restriction is implemented, there is a possibility that an appropriate SSID cannot be searched for. Therefore, even in the power saving mode, in the case where the processing capability is comparatively abundant, it is desirable not to apply the second restriction relating to the channel.

When a large number of channels are to be scanned, the SSID with a high radio wave intensity is not necessarily searched for first. As a result, if the third restriction is implemented, it is possible to cause the list information to be filled with a beacon signal whose electric wave strength is weak. Therefore, even in the power saving mode, when the processing capability is relatively abundant, it is desirable not to implement the third limitation on the number of SSIDs.

On the other hand, when the operation mode is the second operation mode, the processing unit 210 executes, as the second scanning process, a scanning process in which two or more limits among the first limit, the second limit, and the third limit are applied to the first scanning process.

Fig. 10 is a diagram showing an example of the relationship between the operation mode and the scanning process. As shown in fig. 10, the full scan can be performed in the normal operation mode. Therefore, any one of the first, second, and third restrictions is not applied. In the first power saving mode, for example, as described above, the first restriction is applied, and the second restriction and the third restriction are not applied. In addition, in the second power saving mode, using fig. 8 and as described above, the processing section 210 applies all of the first, second, and third restrictions. However, fig. 10 is an example of a limitation in each operation mode. The content of the scanning process in each operation mode is not limited to fig. 10, and various modifications can be made. For example, the second scanning process may omit any one of the first limitation, the second limitation, and the third limitation.

Although the present embodiment has been described in detail as described above, it will be readily apparent to those skilled in the art that a large number of modifications can be made without substantially departing from the novel matters and effects of the present embodiment. Therefore, all such modifications are included in the scope of the present disclosure. For example, a term described at least once in the specification or the drawings together with a different term having a broader meaning or the same meaning can be replaced with the different term anywhere in the specification or the drawings. All combinations of the present embodiment and the modifications are also included in the scope of the present disclosure. The configuration, operation, and the like of the electronic device and the like are not limited to those described in the present embodiment, and various modifications can be made.

Description of the symbols

200 … an electronic device; 210 … processing unit; 211 … CPU; 212 … driver; 213 … application programs; 220 … wireless communication section; 221 … Wi-Fi chip; 230 … display part; 240 … operating part; a 250 … print; 260 … storage section; AP … access points.