Communication device, communication method, and communication system

Abstract

To provide a communication device with which it is possible to communicate selectively using a plurality of communication means and shorten the time until communication becomes possible.SOLUTION: The communication device comprises first communication means, and second communication means that is capable of communicating faster than the first communication means. In order for the second communication means to connect with an external device, it is necessary to communicate with the external device using the first communication means. When breaking a connection established between the second communication means and the external device, the communication device requests the external device to maintain, for a prescribed duration, a state in which the second communication means is kept connectable, in accordance with a cause of breaking the connection.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a communication device, a communication method, and a communication system, and more particularly to a communication technology using a plurality of communication methods. [Background technology]

[0002] Conventionally, communication devices equipped with multiple communication units compatible with multiple wireless communication methods with different characteristics are known (Patent Document 1). When such communication devices communicate with each other, constantly operating the multiple communication units increases power consumption. On the other hand, operating only the communication unit to be used increases the waiting time until communication starts when switching communication units.

[0003] Therefore, in Patent Document 1, the second communication unit, which consumes more power than the first and second communication units, is operated in a power-saving mode, thereby reducing power consumption while keeping the two communication units operating at all times. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-87926 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, by transmitting a request signal through the first communication unit, the second communication unit is switched from power-saving mode to normal mode, and communication is performed by the second communication unit. In the power-saving mode, the second communication unit can only receive data intermittently. Therefore, communication by the first communication unit is required to return the second communication unit to normal mode.

[0006] In view of the problems with the conventional technology, one aspect of the present invention provides a communication device that is capable of communication by selectively using a plurality of communication means and that can reduce the time required for communication to become possible. [Means for solving the problem]

[0007] The above-mentioned object is achieved by a communication device having a first communication means, a second communication means capable of communication at a higher speed than the first communication means, and a control means for controlling the operation of the first communication means and the second communication means, wherein in order to enable the second communication means to connect to the external device, communication with the external device using the first communication means is necessary, and the control means, when terminating the connection established between the second communication means and the external device, requests the external device to maintain a state in which the second communication means can be connected for a predetermined time depending on the cause of the connection terminating. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a communication device that can selectively use a plurality of communication means for communication and can reduce the time required for communication to become possible. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the functional configuration of a smartphone as an example of a communication device according to an embodiment; [Figure 2] FIG. 2 is a block diagram showing an example of the functional configuration of a digital camera as an example of an external device of the communication device of FIG. 1. [Figure 3] Flowchart regarding the operation of the smartphone according to the embodiment [Figure 4] Flowchart regarding the operation of the smartphone according to the embodiment [Figure 5] Flowchart regarding the operation of the digital camera according to the embodiment DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below based on exemplary embodiments with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the claimed invention. Furthermore, although multiple features are described in the embodiments, not all of them are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] In the following embodiments, the present invention will be described with reference to a smartphone and a digital camera. However, the present invention can be implemented in any electronic device (especially a battery-powered and / or portable device) that supports multiple wireless communication methods. Such electronic devices include computer devices (personal computers, tablet computers, media players, PDAs, etc.), game consoles, and wearable devices (smart watches, activity monitors, etc.). These are merely examples, and the present invention can also be implemented in other electronic devices.

[0012] FIG. 1 is a block diagram showing an example of a functional configuration of a smartphone 100 as an example of a communication device according to an embodiment. The control unit 101 has one or more processors (hereinafter referred to as CPUs) capable of executing programs, and executes programs stored in, for example, nonvolatile memory 103 by loading them into working memory 104. The control unit 101 executes the programs to control the operation of each functional block and realize the functions of the smartphone 100.

[0013] Nonvolatile memory 103, which may be rewritable, stores programs (basic software (OS), applications, etc.) executable by the CPU of control unit 101, setting values ​​for smartphone 100 and applications, user data, etc. As will be described later, smartphone 100 also stores in nonvolatile memory 103 information about external devices with which it has communicated and information necessary to resume communication with the external devices with which it has communicated.

[0014] The communication processing of the smartphone 100, which will be described later, is implemented as a function of an application stored in the nonvolatile memory 103. The application does not need to include all of the programs required to realize its functions, and can use functions provided by the OS as appropriate. For example, the OS can provide basic functions related to wireless communication with external devices that comply with a specific wireless communication standard, such as checking the presence or absence of an external device and establishing and disconnecting a wireless connection (link) with an external device.

[0015] The working memory 104 is, for example, a volatile memory, and is used to load programs executed by the CPU of the control unit 101 and to store values ​​required during program execution. In addition, a part of the working memory 104 may be used as a display memory for the display unit 106.

[0016] The imaging unit 102 is a camera unit having a photographing optical system, an imaging element, etc. The imaging unit 102 takes a photograph under the control of the control unit 101, and stores the obtained image data in a working memory 104. The control unit 101 applies predetermined image processing to the image data to generate an image data file. The control unit 101 records the image data file on a recording medium 107, for example.

[0017] The operation unit 105 is a general term for input devices provided on the smartphone 100. The operation unit 105 may include, but is not limited to, a touch panel provided on the display unit 106, a power switch, a volume adjustment button, etc. When the control unit 101 detects an operation on the operation unit 105, it executes an operation corresponding to the detected operation.

[0018] The display unit 106 displays a screen provided by the OS and applications. Note that the smartphone 100 may be connectable to an external display device.

[0019] The recording medium 107 is provided separately from the nonvolatile memory 103 and may be, for example, a semiconductor memory card. The recording medium 107 is used, for example, as a recording destination for image data files generated by the control unit 101, data downloaded by the user, etc. Note that the recording medium 107 may also be used as part of the nonvolatile memory 103 (to expand the capacity of the nonvolatile memory 103).

[0020] The connection unit 108 (second communication means) is a communication interface. The connection unit 108 performs communication with an external device in accordance with one or more well-known wired and wireless communication standards, including a wireless communication standard. The connection unit 108 has circuits (antennas, connectors, transceivers, etc.) according to the communication standard to which it conforms.

[0021] The short-range wireless communication unit 112 (first communication means) is also a communication interface. The short-range wireless communication unit 112 performs communication with an external device in accordance with one or more well-known short-range wireless communication standards. The connection unit 108 has circuits (antennas, transceivers, etc.) that correspond to the communication standards.

[0022] For convenience, it is assumed here that connection unit 108 and short-range wireless communication unit 112, which will be described later, comply with different wireless communication standards. It is also assumed that connection unit 108 complies with a communication standard that has a wider communication range and a higher communication speed than short-range wireless communication unit 112, and that the power consumption required for operation is greater than that of short-range wireless communication unit 112. It is also assumed that communication with the external device using short-range wireless communication unit 112 is necessary in order for connection unit 108 to be able to connect to the external device.

[0023] In order to reduce power consumption of the smartphone 100, the control unit 101 operates the short-range wireless communication unit 112 with priority over the connection unit 108. In principle, the control unit 101 performs, for example, detection of an external device and communication with the detected external device using the short-range wireless communication unit 112. The control unit 101 operates the connection unit 108 only when certain predetermined conditions are met, such as when high-speed communication is required, and communicates with the external device through the connection unit 108.

[0024] Furthermore, the control unit 101 can acquire information (e.g., identification information, a password or encryption key, address information, etc.) necessary for communication with an external device using the connection unit 108 from the external device via the short-range wireless communication unit 112. Switching the communication interface used for communication with the same external device between the short-range wireless communication unit 112 and the connection unit 108 is referred to as handover here.

[0025] In the following description, it is assumed as an example that the connection unit 108 is a wireless communication interface that complies with the wireless LAN (IEEE 802.11 series) standard. Furthermore, it is assumed that the short-range wireless communication unit 112 is a wireless communication interface that complies with Bluetooth (registered trademark) version 4.0 or later, particularly Bluetooth Low Energy (BLE). However, the combination of communication standards that the connection unit 108 and the short-range wireless communication unit 112 comply with may be other combinations as long as the above-described relationship is satisfied.

[0026] The public network connection unit 109 is a communication interface with a mobile communication network, and complies with one or more communication standards (3G, 4G, 5G, etc.) established by, for example, the Third Generation Partnership Project (3GPP).

[0027] The connection unit 108, the short-range wireless communication unit 112, and the public network connection unit 109 may share a part of the circuit.

[0028] The microphone 110 is used for making calls and inputting voice commands. The microphone 110 as an input device for voice commands is included in the operation unit 105. The speaker 111 is used for calls and audio playback.

[0029] 2 is a block diagram showing an example of the functional configuration of a digital camera 200 as an example of an external device capable of communicating with the smartphone 100. The external device may be any portable or battery-powered electronic device capable of communicating with each of the connection unit 108 and the short-range wireless communication unit 112 of the smartphone 100.

[0030] The control unit 201 has one or more processors (hereinafter referred to as CPUs) capable of executing programs, and executes programs stored in, for example, nonvolatile memory 203 by loading them into work memory 204. By executing the programs, the control unit 201 controls the operation of each functional block and realizes the functions of the digital camera 200.

[0031] The nonvolatile memory 203, which may be rewritable, stores programs executable by the CPU of the control unit 201, setting values ​​for the digital camera 200, GUI data, etc. The nonvolatile memory 203 also stores information about external devices with which communication has been performed.

[0032] It is assumed that the communication processing of the digital camera 200 , which will be described later, is implemented as a function of a program stored in the nonvolatile memory 203 .

[0033] The working memory 204 is, for example, a volatile memory, and is used to read programs executed by the CPU of the control unit 201 and to store values ​​required during program execution. In addition, a part of the working memory 204 may be used as a display memory for the display unit 206.

[0034] The imaging unit 202 is a camera unit having an imaging optical system, an imaging element, etc. The imaging unit 202 takes an image under the control of the control unit 201 and stores the obtained image data in the working memory 204. The control unit 201 applies predetermined image processing to the image data to generate an image data file. The control unit 201 records the image data file, for example, on a recording medium 207. The control unit 201 also applies predetermined image processing to the image data to generate image data for display. The control unit 201 stores the image data for display in a video memory area of ​​the working memory 204, synthesizes an image showing information such as current setting values, and displays it on the display unit 206.

[0035] While a moving image is being captured by the imaging unit 202, the captured moving image can be immediately displayed on the display unit 206, thereby making the display unit 206 function as an electronic viewfinder (EVF). The moving image displayed to make the display unit 206 function as an EVF is called a live view image.

[0036] The operation unit 205 is a general term for the input devices provided in the digital camera 200. The operation unit 205 may include, but is not limited to, a touch panel provided on the display unit 206, a power switch, a shutter button, a video recording button, directional keys, a setting button, a menu button, etc. When the control unit 201 detects an operation on the operation unit 205, it executes an operation corresponding to the detected operation.

[0037] The display unit 206 is used to display images captured by the imaging unit 202, images recorded on the recording medium 207, menu screens, etc. The digital camera 200 may be connectable to an external display device.

[0038] The recording medium 207 may be, for example, a semiconductor memory card, and is provided separately from the nonvolatile memory 203. The recording medium 207 is used as a recording destination for image data files generated by the control unit 201, for example.

[0039] The connection unit 208 is a communication interface. The connection unit 208 communicates with an external device in accordance with one or more known wired and wireless communication standards, including a wireless communication standard. The connection unit 208 has circuits (antennas, connectors, transceivers, etc.) that correspond to the communication standards to which it conforms.

[0040] The short-range wireless communication unit 209 is also a communication interface. The short-range wireless communication unit 209 performs communication with an external device in accordance with one or more known short-range wireless communication standards. The connection unit 208 has circuits (antennas, transceivers, etc.) that correspond to the communication standards.

[0041] For convenience, it is assumed here that connection unit 208 and short-range wireless communication unit 209, which will be described later, comply with different wireless communication standards. It is also assumed that connection unit 208 complies with a communication standard that has a wider communication range and a higher communication speed than short-range wireless communication unit 209, and that the power consumption required for operation is greater than that of short-range wireless communication unit 209. There are no particular restrictions on the combination of communication standards that connection unit 208 and short-range wireless communication unit 209 comply with, as long as the above-mentioned relationship is satisfied.

[0042] In this embodiment, the digital camera 200 communicates with the connection unit 108 and short-range wireless communication unit 112 of the smartphone 100. Therefore, the connection unit 208 is a wireless communication interface that complies with the wireless LAN (IEEE 802.11 series) standard, and the short-range wireless communication unit 209 is a wireless communication interface that complies with Bluetooth Low Energy (BLE). The connection unit 208 and the short-range wireless communication unit 209 may share part of the circuit.

[0043] Furthermore, the connection unit 208 communicates with the connection unit 108 in infrastructure mode and therefore functions as an access point (AP). That is, the connection unit 208 has a function of forming a network to which the smartphone 100 can connect. However, the connection unit 208 functions as a simple AP that does not have a gateway function of transferring data received from an external device connected to the network that the connection unit 208 has formed to another network.

[0044] In order to reduce the power consumption of the digital camera 200, the control unit 201 operates the short-range wireless communication unit 209 with priority over the connection unit 208. In principle, the control unit 201 performs, for example, detection of an external device and communication with the detected external device using the short-range wireless communication unit 209. The control unit 201 operates the connection unit 208 and communicates with the external device via the connection unit 208 only when a specific predetermined condition is met, such as when a request is received from an external device via the short-range wireless communication unit 112.

[0045] Next, the operation of the smartphone 100 regarding communication control with an external device (digital camera 200) will be described. First, while the connection unit 108 is not operating, the control unit 101, for example, periodically executes an operation of detecting an external device by the short-range wireless communication unit 112. Note that the operation of detecting an external device may differ depending on the standard to which the short-range wireless communication unit 112 conforms.

[0046] When the short-range wireless communication unit 112 detects an external device, the control unit 101 transmits a connection request from the short-range wireless communication unit 112 to the external device and executes a procedure for establishing a wireless connection. This procedure may differ depending on the communication standard. Furthermore, any procedures required before establishing the wireless connection are also executed. For example, when the short-range wireless communication unit 112 performs communication in accordance with BLE, if the external device is not paired, the procedure required for establishing a wireless connection is executed after pairing. On the other hand, if the detected external device is already paired, the control unit 101 uses pairing information stored in the non-volatile memory 103 to transmit a connection request to the external device from the short-range wireless communication unit 112.

[0047] When a wireless connection is established between the short-range wireless communication units 112 and 309, communication becomes possible between the smartphone 100 and the digital camera 200. For example, an application running on the smartphone 100 can communicate with the digital camera 200 in response to a user instruction or the occurrence of a predetermined event.

[0048] When using communication faster than that by the short-range wireless communication unit 112, the control unit 101 executes a procedure for establishing a wireless connection between the connection units 108 and 309. The case when using communication faster than that by the short-range wireless communication unit 112 can be determined in advance. For example, when transferring image data from the digital camera 200 to the smartphone 100, this may be when an instruction is received from the user.

[0049] The control unit 101 transmits a request to activate the connection unit 208 (simple AP) to the digital camera 200 via the short-range wireless communication unit 112. When the control unit 201 of the digital camera 200 receives the request to activate the connection unit 208, it activates the connection unit 208. As a result, the connection unit 208 generates a network as a simple AP. The control unit 201 also transmits information required to connect to the network generated by the connection unit 208 to the smartphone 100 via the short-range wireless communication unit 209.

[0050] When the control unit 101 receives information for the connection unit 108 to connect to the network generated by the connection unit 208 of the digital camera 200 from the digital camera 200 via the short-range wireless communication unit 112, the control unit 101 stores the information in the non-volatile memory 103. Here, it is assumed that the SSID, password (encryption key), and IP address are received as the information for connecting to the network generated by the connection unit 208. However, this information may differ depending on the standards that the connection units 108 and 308 comply with.

[0051] The control unit 101 activates the connection unit 108 and acquires information about networks present in the vicinity. Then, if the control unit 101 can confirm the SSID included in the information received from the digital camera 200, it transmits a connection request from the connection unit 108. Note that the connection request may be transmitted from the connection unit 108 after a certain time has elapsed since the activation request for the connection unit 208 was transmitted to the digital camera 200.

[0052] In the subsequent authentication process, the control unit 101 uses the password received from the digital camera 200. If the authentication is successful, a wireless connection is established between the connection units 108 and 308. This enables faster communication between the connection units 108 and 308 than communication between the short-range wireless communication units 112 and 309.

[0053] The operation of smartphone 100 when communication via connection unit 108 is terminated while the wireless connection between connection units 108 and 308 has been established will be described using the flowchart shown in Fig. 3. This operation can be performed when control unit 101 detects that the cooperative application using the wireless connection between connection units 108 and 308 has changed from an active state.

[0054] In S301, the control unit 101 checks the cause of the change of the cooperative application from an active state to an inactive state. Specifically, the control unit 101 determines whether the cause of the change of the cooperative application from an active state to an inactive state is an explicit operation to close the application. If the control unit 101 determines that the cause of the change of the cooperative application from an active state to an inactive state is an explicit operation to close the application, the control unit 101 executes S303; otherwise, the control unit 101 executes S302. Note that the change of the cooperative application from an active state to an inactive state is an example of an event that requires the disconnection of the wireless connection between the connection units 108 and 308. Therefore, S301 may be a determination, when an event that requires the disconnection of the wireless connection between the connection units 108 and 308 occurs, of whether the event is considered to have occurred due to the user's explicit intention.

[0055] The causes of the change of the cooperative application from an active state to an inactive state may include, for example, the following operations. (1) An operation defined as an application termination operation in the OS on which the linked application is running, (2) Transitioning a linked application from an active state to an inactive state (3) Exit operations defined by the linked application (such as selecting Exit from the menu screen) Note that the operations (1) to (3) are merely examples and may differ depending on the OS and application.

[0056] The operation for transitioning from the active state to the inactive state may be, for example, an operation for moving an application window from the foreground (an operation for transitioning an application from the foreground to the background).

[0057] In S301, the control unit 101 determines that, for example, the operation (1) or (3) is an explicit operation to terminate the application. On the other hand, the control unit 101 does not determine, for example, the operation (2) as an explicit operation to terminate the application. This is because, in the case of the operation (2), the application may be returned to an active state again.

[0058] Note that even if it is determined in S301 that the operation is an explicit termination operation, the cooperative application is not terminated and the wireless connection between the connection units 108 and 308 is not disconnected. The control unit 101 maintains the wireless connection between the connection units 108 and 308 until a request to disconnect the wireless connection is made in S305, which will be described later.

[0059] In S302, the control unit 101 determines the simple AP duration to be a predetermined time other than 0 (for example, 30 seconds), and then executes S304. In S303, the control unit 101 sets the simple AP duration to 0, and then executes S304.

[0060] When an integrated application changes from an active state without an explicit termination operation, the integrated application may be temporarily inactive and may return to an active state in a short time. In this case, the control unit 101 determines a non-zero simple AP duration to request the wirelessly connected device (digital camera 200) to maintain a connectable state for a predetermined period of time. On the other hand, when an explicit termination operation is performed for the integrated application, it is considered that the user clearly intends to terminate the integration with the digital camera 200. Therefore, the control unit 101 sets the simple AP duration to 0, and prioritizes reducing power consumption due to the operation of the connection unit 208 over shortening the reconnection time.

[0061] In S304, the control unit 101 transmits the simple AP duration determined in S302 or S303 to the digital camera 200 from the connection unit 108. The control unit 201 of the digital camera 200 stores the simple AP duration received by the connection unit 208 in the work memory 104, for example.

[0062] In S305, the control unit 101 transmits a request to disconnect the wireless connection with the connection unit 208 from the connection unit 108 to the digital camera 200. The control unit 101 also disconnects the wireless connection, for example, by stopping the operation of the connection unit 108. Furthermore, the control unit 101 acquires the current time, for example, from a clock circuit, and stores it in the work memory 104. In addition, if the control unit 101 determines in S301 that the operation that requires disconnecting the wireless connection between the connection units 108 and 308 is an explicit application termination operation, it terminates the linked application.

[0063] If the OS of the smartphone 100 has an automatic reconnection function for networks that have been previously connected, the control unit 101 excludes the network created by the digital camera 200 (connection unit 208) from the targets for automatic reconnection. This prevents applications other than the cooperative application that uses the digital camera 200 from connecting to the network created by the digital camera 200. The operation of excluding the network created by the digital camera 200 from the targets for automatic reconnection can be performed at any time after the smartphone 100 has first connected to the network created by the digital camera 200.

[0064] When connection unit 208 receives a request to disconnect the wireless connection, control unit 201 checks whether a non-zero simple AP duration is stored in working memory 204. If the simple AP duration is set, control unit 201 maintains the operation of connection unit 208 until the simple AP duration has elapsed since the disconnection request was received. As a result, connection unit 208 maintains a state in which it can be connected to from connection unit 108 for a certain period of time, even after receiving the disconnection request from smartphone 100.

[0065] Next, an operation performed when an operation to transition (return) a cooperative application from the background to the foreground is detected in the smartphone 100 will be described with reference to the flowchart of FIG.

[0066] In S401, the control unit 101 determines whether or not previous connection information related to the connection unit 108 is stored in the work memory 104 (or non-volatile memory 103). The previous connection information includes the SSID, password (encryption key), and IP address used when the connection unit 108 last communicated with an external device. If the previous connection information is stored, the control unit 101 executes S402, and if not, the control unit 101 executes S405.

[0067] In S402, the control unit 101 determines whether the time elapsed since the connection unit 108 most recently disconnected the wireless connection is within a predetermined time. The predetermined time used here is the simple AP duration time set in S302. The control unit 101 can make this determination based on the disconnection time stored in S305 and the current time acquired from the clock circuit. If the control unit 101 determines that the elapsed time is within the predetermined time, it executes S403, and if not (if the elapsed time is greater than the predetermined time), it executes S405.

[0068] In S403 , the control unit 101 uses the previous connection information stored in the nonvolatile memory 103 to send a connection request from the connection unit 108 .

[0069] In S404, the control unit 101 determines whether a wireless connection with the digital camera 200 has been established via the connection unit 108. If it is determined that a wireless connection has been established, the control unit 101 ends the processing shown in Fig. 4. If it is not determined that a wireless connection has been established, the control unit 101 executes S405.

[0070] Steps S405 to S407 are processes for executing reconnection of the connection unit 108 through communication using the short-range wireless communication unit 112. In S405, the control unit 101 establishes a wireless connection with the digital camera 200 via the short-range wireless communication unit 112. Note that if the wireless connection of the short-range wireless communication unit 112 is maintained, S405 does not need to be executed.

[0071] In S406, the control unit 101 transmits a request to activate the simple AP to the digital camera 200 via the short-range wireless communication unit 112. Upon receiving the request to activate the simple AP (connection unit 208), the control unit 201 of the digital camera 200 activates the connection unit 208. As a result, the connection unit 208 generates a network as a simple AP. The control unit 201 also transmits information (connection information) required to connect to the network generated by the connection unit 208 to the smartphone 100 via the short-range wireless communication unit 209.

[0072] In S407, the control unit 101 transmits a connection request from the connection unit 108 using the connection information acquired from the digital camera 200. After that, a wireless connection between the connection units 108 and 209 is established after an authentication process.

[0073] After sending a request to activate the connection unit 208 to the digital camera 200 in S406, the connection request may be sent using the previously used connection information stored in the non-volatile memory 103 without waiting for the connection information to be received.

[0074] In S408, the control unit 101 stores the connection information received in S406 in the non-volatile memory 103. Note that the storage of the connection information may be performed in S406.

[0075] In this embodiment, when a wireless connection is terminated due to a change in the active state of a cooperative application that uses wireless communication, the cause of the change in state is investigated. If the change in state is not due to an explicit termination operation of the application, the other device is requested to maintain a connectable state for a certain period of time. Therefore, if the application returns to an active state in a short period of time, the time required to re-establish a wireless connection with the other device can be shortened.

[0076] 5, the operation control of the connection unit 208 in the digital camera 200 will be described. Here, it is assumed that a wireless connection with the other device (smartphone 100) has been established via the short-range wireless communication unit 209, and the connection unit 208 is not operating.

[0077] In S501, the control unit 201 determines whether or not a startup request for the connection unit 208 has been received from the smartphone 100 via the short-range wireless communication unit 209. If it is determined that a startup request has been received, the control unit 201 executes S502, and if not, executes S501, for example, periodically.

[0078] In S502, the control unit 201 activates the connection unit 208 and executes the simple AP function, whereby the connection unit 208 generates a network that can be connected from the connection unit 108.

[0079] In S503, the control unit 201 transmits information (connection information) necessary for connecting to the network generated by the connection unit 208 to the smartphone 100 via the short-range wireless communication unit 209.

[0080] In S504, the control unit 201 determines whether or not a connection request has been received from the smartphone 100 (connection unit 108) via the connection unit 208. If it is determined that a connection request has been received, the control unit 201 executes S505, and if not, executes S504, for example, periodically.

[0081] In S505, the control unit 201 executes authentication processing for the sender of the connection request (smartphone 100). Here, it is assumed that the password (encryption key) included in the connection information sent to the smartphone 100 is confirmed and authentication of the smartphone 100 is successful. Note that the authentication processing method and the processing to be performed when authentication fails may differ depending on the communication standard.

[0082] If the authentication is successful, a wireless connection conforming to the wireless LAN standard is established between the connection units 108 and 208, enabling faster communication than a wireless connection conforming to BLE between the short-range wireless communication units 112 and 309. For example, communication with a large amount of data, such as image data transfer from the digital camera 200 to the smartphone 100, can be performed wirelessly using the connection units 108 and 208. Furthermore, when the control unit 201 receives the simple AP duration from the smartphone 100 via the connection unit 208, it stores the received simple AP duration in, for example, the non-volatile memory 203.

[0083] In S506, the control unit 201 determines whether or not a disconnection request has been received from the smartphone 100 (connection unit 108) via the connection unit 208. If it is determined that a disconnection request has been received, the control unit 201 executes S507, and if not, the control unit 201 executes S506, for example, periodically.

[0084] In S507, the control unit 201 determines whether the wireless connection of the connection unit 208 has been disconnected. This is a determination as to whether the wireless connection has been disconnected without following a normal procedure, for example, due to a deterioration in communication conditions. If it is determined that the wireless connection has been disconnected, the control unit 201 executes S508, and if not, the control unit 201 executes S506.

[0085] For example, if the wireless connection is disconnected due to a deterioration in communication conditions, the control unit 101 of the smartphone 100 notifies the display unit 106 that the connection has been disconnected. This notification may include a software button that instructs reconnection. Then, when the control unit 101 detects a button operation instructing reconnection, it can send a connection request from the connection unit 108 using the connection information stored in the nonvolatile memory 103.

[0086] In S508, the control unit 201 waits until a predetermined time has elapsed while maintaining the operation of the connection unit 208. If a connection request is received before the predetermined time has elapsed, the control unit 201 executes S505. If a connection request is not received before the predetermined time has elapsed, the control unit 201 executes S511 and terminates the operation of the connection unit 208.

[0087] The predetermined time for maintaining the operation of the connection unit 208 in S508 can be set in advance to, for example, several tens of seconds to one minute so as to enable quick reconnection when a reconnection command is immediately given from the smartphone 100, while suppressing unnecessary power consumption. This predetermined time can be stored in the nonvolatile memory 203, for example.

[0088] In this way, when the wireless connection of connection unit 208 is disconnected without following the normal procedure, control unit 201 does not immediately stop the operation of connection unit 208, but maintains the operating state for a certain period of time. As a result, when the connection is unintentionally disconnected due to a deterioration in the communication state or the like, the connection can be restored in a short time without requesting that connection unit 208 be started again.

[0089] In S509, the control unit 201 refers to the nonvolatile memory 103 and determines whether the simple AP duration set by the smartphone 100 is not 0 (greater than 0). If the control unit 201 determines that the simple AP duration is not 0, it executes S510. On the other hand, if the control unit 201 determines that the simple AP duration is 0, it executes S511 and terminates the operation of the connection unit 208.

[0090] In S510, the control unit 201 waits until the simple AP duration has elapsed while maintaining the operation of the connection unit 208. If a connection request is received before the simple AP duration has elapsed, the control unit 201 executes S505. If a connection request is not received before the simple AP duration has elapsed, the control unit 201 executes S511 and terminates the operation of the connection unit 208.

[0091] In this embodiment, when the wireless connection is terminated due to a change from an active state of an application using wireless communication, the control unit 101 determines the simple AP duration time according to the cause of the state change and transmits it to the other device (digital camera 200). However, when the control unit 201 of the digital camera 200 receives a request to terminate the wireless connection via the connection unit 208, it may wait for a certain period of time before terminating the operation of the connection unit 208.

[0092] Furthermore, when digital camera 200 is receiving power from an external source (for example, when it is receiving power from a commercial power source), even if a request to disconnect the wireless connection is received through connection unit 208, operation of connection unit 208 may continue.

[0093] In this way, in a communication device having two communication units with different communication speeds, when disconnecting the connection between the communication unit capable of high-speed communication and an external device, the device requests the external device to maintain a connectable state for the communication unit capable of high-speed communication for a predetermined period of time depending on the cause of the disconnection. For example, if the cause of the disconnection is not an explicit termination operation of an application using high-speed communication, the device requests the external device to maintain a connectable state for the communication unit capable of high-speed communication for a predetermined period of time. This makes it possible to shorten the time required to reconnect when, for example, an application is temporarily inactive.

[0094] The disclosure of the present embodiment includes the following communication device, communication method, communication system, and program. (Item 1) a first means of communication; a second communication means capable of communication at a higher speed than the first communication means; a control means for controlling the operation of the first communication means and the second communication means; In order to enable the second communication means to connect to an external device, communication with the external device using the first communication means is required; A communication device characterized in that, when disconnecting a connection established between the second communication means and an external device, the control means requests the external device to maintain a state in which the second communication means can be connected for a predetermined time, depending on the cause of the disconnection. (Item 2) The communication device described in item 1 is characterized in that the control means requests the external device to maintain a connectable state for the second communication means for a predetermined period of time when the cause of the disconnection is that an application using communication with the external device via the second communication means has changed from an active state without an explicit termination operation. (Item 3) The communication device described in item 1 or 2, characterized in that the control means requests the external device to maintain a connectable state of the second communication means for a predetermined time when the cause of the disconnection is an operation to transition an application that uses communication with the external device via the second communication means from the foreground to the background. (Item 4) The communication device described in any one of items 1 to 3, characterized in that if the cause of the disconnection is an explicit termination operation of an application that uses communication with the external device via the second communication means, the control means does not request the external device to maintain a connectable state of the second communication means for a predetermined period of time. (Item 5) The communication device according to any one of items 1 to 4, characterized in that, after disconnecting the connection between the second communication means and the external device, when communicating with the external device via the second communication means, the control means sends a connection request to the external device from the second communication means without communicating with the external device via the first communication means. (Item 6) The communication device described in item 5, characterized in that the control means sends a predetermined request from the first communication means to the external device if a connection between the second communication means and the external device is not established by the connection request. (Item 7) a first means of communication; a second communication means capable of communication at a higher speed than the first communication means; a control means for controlling the operation of the first communication means and the second communication means; The control means activating the second communication means when a request is received from an external device via the first communication means; a communication device that, when receiving a request to disconnect the connection between the second communication means and the external device from the external device through the second communication means, maintains operation of the second communication means for a first predetermined time and then terminates operation of the second communication means. (Item 8) 8. The communication device according to item 7, wherein the first predetermined time is received from the external device. (Item 9) 9. The communication device according to item 7 or 8, wherein the control means immediately terminates operation of the second communication means upon receiving the disconnection request if the first predetermined time is 0. (Item 10) The communication device according to any one of items 7 to 9, characterized in that, when the connection between the second communication means and the external device is disconnected without receiving the disconnection request, the control means maintains operation of the second communication means for a second predetermined time and then terminates operation of the second communication means. (Item 11) A communication device according to any one of items 1 to 6; The communication device according to any one of items 7 to 10 as an external device of the communication device according to any one of items 1 to 6; A communication system having: (Item 12) a first means of communication; a second communication means capable of communication at a higher speed than the first communication means; A communication method executed by a communication device that needs to communicate with an external device using said first communication means in order to enable said second communication means to connect to said external device, comprising: when disconnecting the connection established between the second communication means and the external device, requesting the external device to maintain a connectable state of the second communication means for a predetermined time period in accordance with a cause for disconnecting the connection; A communication method comprising: (Item 13) a first means of communication; a second communication means capable of communication at a higher speed than the first communication means, activating the second communication means when a request is received from an external device via the first communication means; when receiving a request to disconnect the connection between the second communication means and the external device from the external device through the second communication means, maintaining operation of the second communication means for a first predetermined time period, and then terminating operation of the second communication means; A communication method comprising: (Item 14) A program for causing a computer to function as a control means possessed by the communication device according to any one of items 1 to 10.

[0095] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0096] The present invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Therefore, the following claims are appended to clarify the scope of the invention. [Explanation of symbols]

[0097] 101...control unit, 102...imaging unit, 103...nonvolatile memory, 104...work memory, 105...operation unit, 106...display unit, 107...storage medium, 108...connection unit, 109...public network connection unit, 110...microphone, 111...speaker, 112...short-range wireless communication unit

Claims

1. A first communication means; a second communication means capable of communication at a higher speed than the first communication means; A control means for controlling the operation of the first communication means and the second communication means, In order to enable the second communication means to connect to an external device, communication with the external device using the first communication means is necessary; A communication device characterized in that, when disconnecting a connection established between the second communication means and an external device, the control means requests the external device to maintain a connectable state of the second communication means for a predetermined period of time, depending on the cause of the disconnection.

2. The communication device according to claim 1, characterized in that the control means requests the external device to maintain a connectable state of the second communication means for a predetermined period of time when the cause of severing the connection is that an application using communication with the external device via the second communication means has changed from an active state without an explicit termination operation.

3. The communication device according to claim 1, characterized in that when the cause of severing the connection is an operation of transitioning an application that uses communication with the external device via the second communication means from the foreground to the background, the control means requests the external device to maintain a state in which the second communication means can be connected for a predetermined period of time.

4. The communication device according to claim 1, characterized in that, when the cause of severing the connection is an explicit termination operation of an application that uses communication with the external device via the second communication means, the control means does not request the external device to maintain a connectable state of the second communication means for a predetermined period of time.

5. The communication device according to claim 1, characterized in that, when communicating with the external device via the second communication means after disconnecting the connection between the second communication means and the external device, the control means sends a connection request to the external device from the second communication means without communicating with the external device via the first communication means.

6. The communication device according to claim 5, characterized in that the control means transmits a predetermined request from the first communication means to the external device when a connection between the second communication means and the external device is not established by the connection request.

7. A first communication means; a second communication means capable of communication at a higher speed than the first communication means; A control means for controlling the operation of the first communication means and the second communication means, The control means activating the second communication means when a request is received from an external device via the first communication means; a communication device that, when receiving a request to disconnect the second communication means from the external device via the second communication means, maintains operation of the second communication means for a first predetermined time and then terminates operation of the second communication means.

8. 8. The communication device according to claim 7, wherein the first predetermined time is received from the external device.

9. 8. The communication device according to claim 7, wherein said control means immediately terminates the operation of said second communication means upon receiving said disconnection request when said first predetermined time is 0.

10. The communication device according to claim 7, characterized in that, when the connection between the second communication means and the external device is disconnected without receiving the disconnection request, the control means maintains operation of the second communication means for a second predetermined time and then terminates operation of the second communication means.

11. A communication device according to any one of claims 1 to 6, A communication device according to any one of claims 7 to 10 as an external device of the communication device according to any one of claims 1 to 6; A communication system having the above configuration.

12. A first communication means; A second communication means capable of communication at a higher speed than the first communication means, A communication method executed by a communication device that requires communication with an external device using the first communication means in order to enable the second communication means to connect the external device, comprising: when disconnecting a connection established between the second communication means and an external device, requesting the external device to maintain a connectable state of the second communication means for a predetermined period of time according to a cause for disconnecting the connection; A communication method comprising:

13. A first communication means; a second communication means capable of communication at a higher speed than the first communication means, activating the second communication means when a request is received from an external device via the first communication means; when receiving a request for disconnection between the second communication means and the external device from the external device via the second communication means, maintaining an operation of the second communication means for a first predetermined time period and then terminating the operation of the second communication means; A communication method comprising:

14. A program for causing a computer to function as the control means of the communication device according to any one of claims 1 to 10.

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