JP6161316B2 - COMMUNICATION DEVICE, COMMUNICATION DEVICE CONTROL METHOD, PROGRAM - Google Patents

Description

  The present invention relates to a communication device, a communication device control method, and a program.

  In recent years, there is an increasing number of cases where a wireless LAN station function is installed in an electronic device such as a digital camera or a printer, and the electronic device is used as a communication device connected to a wireless LAN. For example, Patent Document 1 discloses a method for facilitating image sharing by mounting a wireless LAN function in a digital camera.

  In addition, a standard called Wi-Fi Direct (registered trademark) has been established by Wi-Fi Alliance. In Wi-Fi Direct, a protocol that determines whether each electronic device operates as a wireless LAN access point or a wireless LAN station is defined. By executing the protocol, it is possible to automatically determine which of the electronic devices will be the wireless LAN access point and which of the electronic devices will be the wireless LAN station, thus improving the convenience for the user.

  In Wi-Fi Direct, a function (service discovery function) for advertising / searching service information supported by a higher-level application is also defined as an optional function. According to the present service discovery function, it is possible to know service information held by the electronic device that is the connection partner before executing the connection process, which improves user convenience.

JP 2011-35768 A

However, since service discovery is an optional function in Wi-Fi Direct, a service search response cannot be received from a device that does not support the function. For this reason, it is not possible to search for other devices that do not support service discovery even though the service discovery can be executed only by using service discovery.
It is an object of the present invention to appropriately detect a device that can execute a desired service.

  As means for solving the above-mentioned problems, the communication device of the present invention is capable of executing a predetermined service based on communication in the first communication layer after establishing a wireless network with the first other communication device. A first detection unit for detecting the communication device and a second communication layer different from the first communication layer when the first other communication device is not detected by the first detection unit. Based on communication via a wireless network, a second detection unit that detects an executable service of the first other communication device, and the second detection unit causes the first other communication device to If it is not possible to detect that the predetermined service is executable, the wireless network constructed with the first other communication device is terminated, and the second other communication detected by the first detection means Equipment and And having a construction means for constructing a line network.

  According to the present invention, it is possible to appropriately detect a device that can execute a desired service.

It is a block diagram which shows the hardware constitutions of an apparatus. It is a block diagram which shows the software function structure of an apparatus. It is a figure which shows an example of the network structure in this embodiment. 3 is an operation flowchart of the apparatus according to the first embodiment. FIG. 3 is an operation sequence diagram according to the first embodiment. FIG. 3 is an operation sequence diagram according to the first embodiment. FIG. 10 is an operation flowchart of the apparatus according to the second embodiment. FIG. 10 is an operation sequence diagram according to the second embodiment. FIG. 10 is an operation sequence diagram according to the second embodiment. FIG. 10 is an operation sequence diagram according to the third embodiment. FIG. 10 is an operation sequence diagram according to the third embodiment. FIG. 10 is a diagram illustrating an example of a network configuration in the present embodiment in Example 3. 10 is an operation flowchart of the apparatus according to the first embodiment.

Example 1
Hereinafter, the communication apparatus according to the present embodiment will be described in detail with reference to the drawings. In the following, an example using a wireless LAN system compliant with the IEEE 802.11 series will be described, but the communication form is not necessarily limited to the wireless LAN compliant with IEEE 802.11.

  A hardware configuration in a case suitable for the present embodiment will be described. FIG. 1 shows an example of the configuration of each device described later. In FIG. 1, reference numeral 101 denotes the entire apparatus. A control unit 102 controls the entire apparatus by executing a control program stored in the storage unit 103.

  A storage unit 103 stores a control program executed by the control unit 102 and various types of information such as communication parameters. Various operations described later are performed by the control unit 102 executing a control program stored in the storage unit 103.

  A wireless unit 104 performs wireless LAN communication conforming to the IEEE802.11 series. Reference numeral 105 denotes a display unit that performs various displays, and has a function capable of outputting visually recognizable information such as an LCD or LED, or outputting sound such as a speaker. The display unit 105 has a function of outputting at least one of visual information and sound information.

  Reference numeral 107 denotes an antenna control unit, and reference numeral 108 denotes an antenna. An operation unit 109 is used by the user to perform various inputs and operate the communication apparatus. The service execution unit 110 has a function of executing application level service information provided by the communication device. For example, when the communication device is a printer and can execute a print service, the service execution unit 110 is hardware such as a print engine for executing the print service. Further, for example, when the communication device is a digital camera and can execute a captured image (moving image) distribution service, the service execution unit 110 is hardware such as an imaging element and a lens for realizing an imaging function. FIG. 1 is an example, and the communication apparatus 101 may have a hardware configuration other than the hardware configuration shown in FIG.

  FIG. 2 is a block diagram illustrating an example of the configuration of software function blocks that execute processing and communication control functions shown in flowcharts and sequence diagrams described later. Reference numeral 201 denotes an entire software function block. A Discovery control unit 202 executes a search process for searching for a communication device that is a communication partner.

  Reference numeral 203 denotes a Wi-Fi Direct control unit. Control based on the Wi-Fi Direct protocol specification is performed. In Wi-Fi Direct, a communication device that performs a wireless LAN access point function is referred to as a P2P group owner (hereinafter referred to as GO), and a communication device that performs a wireless LAN station function is referred to as a P2P client (hereinafter referred to as CL). These roles are determined by the GO Negotiation protocol and are defined in the Wi-Fi Direct specification. In Wi-Fi Direct, a network held by GO is referred to as a P2P group. Also in this specification, a network may be described as a P2P group. Both are described with the same meaning.

  In this specification, a P2P group owner (GO), a P2P client (CL), and a communication device group whose role has not been determined are collectively referred to as a P2P device. The P2P device automatically determines whether to join a wireless network (CL function) or to build a wireless network (GO function) by implementing the Wi-Fi Direct protocol. Then, it operates with one of the determined functions, and performs wireless connection and wireless communication. Further, when connecting between devices using Wi-Fi Direct, a communication parameter is provided from GO to CL, and the connection is made using the communication parameter. The communication parameters include various wireless communication parameters for performing wireless communication in accordance with the IEEE 802.11 standard. That is, the communication parameters include wireless communication parameters necessary for performing wireless LAN communication such as an SSID as a network identifier, an encryption method, an encryption key, an authentication method, and an authentication key. It also includes an IP address for communication on the IP layer.

  Reference numeral 204 denotes a service discovery control unit that manages the service discovery function. The service discovery function can exchange service information held by each partner communication apparatus by transmitting and receiving an action frame (GAS frame) defined by IEEE802.11u. Note that GAS is an abbreviation for Generic Advertisement Service. Specifically, when searching for an attribute of another communication device or a corresponding service, an “SD Query” frame (GAS Initial Request) that is a service search signal is transmitted. Then, an “SD Response” frame, which is a response to the SD Query, is received as a response from the partner apparatus. Alternatively, an SD Query from the partner apparatus is received and an SD Response is transmitted as a response. By transmitting and receiving these frames, it is possible to detect attributes of other communication devices and executable services. In addition, it is possible to advertise services that can be executed by the device itself to other communication devices. Further, when there is no response of the transmitted SD Query, it is possible to determine whether or not the service discovery function that is an optional function of Wi-Fi Direct of another communication apparatus is supported. That is, the service discovery control unit 204 executes a device service search for detecting attribute information of other communication devices existing in a wireless communication range in a communication layer for performing wireless communication. The service discovery control unit 204 performs an attribute detection process for other devices in the first communication layer. In the present embodiment, the first communication layer is exemplified by the data link layer in the OSI reference model, but is not limited thereto.

  In the service search processing by SD Query, a search for obtaining a response from a device that can execute the desired service by specifying a desired service, and all services that can be executed by other communication devices without specifying the desired service. There is a search for services.

  Note that the service information includes information related to protocols used for mutual execution of service communication, and service function correspondence information indicating correspondence between essential functions and optional functions of the service. For example, the service information received from another communication device can determine whether or not the other communication device can execute a predetermined service (for example, whether or not it supports a print service). Further, it is possible to determine a protocol (for example, whether print service by PictBridge can be executed) when another communication device performs a predetermined service based on service information received from another communication device. Also, service function support information when another communication device performs a predetermined service based on service information received from another communication device (for example, whether the print service supports double-sided printing, color or monochrome printing, and format printing) Can be determined. It should be noted that the specific examples here are not intended to limit the invention, but are merely examples for deepening understanding.

  Reference numeral 205 denotes an L3 Service Discovery control unit that controls a service discovery function at the network layer (layer 3) in the OSI reference model. The service discovery function can be executed by using technologies such as UPnP (registered trademark) (Universal Plug and Play) and Bonjour (registered trademark). That is, the L3 Service Discovery control unit 205 can transmit and receive service information in a second communication layer different from the first communication layer in which the service discovery control unit 204 transmits and receives service information by other communication devices. In other words, even if the communication partner device does not support the service discovery function that is an optional function of Wi-Fi Direct, if the communication partner device supports UPnP or Bonjour, service information can be transmitted to and received from the communication partner device. Can do. In the present embodiment, the second communication layer is described as a network layer, but any communication layer higher than the first communication layer may be used.

  The L3 Service Discovery control unit 205 can notify other communication devices of services (types of processing) that can be provided by the own device, similar to the service information control unit 204 advertising and searching service information. In addition, it is possible to acquire a service (type of processing) that can be provided by another communication apparatus. Note that the service information transmitted and received by the service discovery control unit 204 and the service information transmitted and received by the L3 Service Discovery control unit 205 may have the same contents or different information.

  In the service search processing by the L3 Service Discovery control unit 205, a search specifying a desired service and a search not specifying a desired service can be executed. When executing the service search process, the L3 Service Discovery control unit 205 transmits a search signal in the second communication layer.

  Reference numeral 206 denotes a packet receiving unit, and 207 denotes a packet transmitting unit, which controls transmission / reception of all packets including upper layer communication protocols. Reference numeral 208 denotes a service providing unit in the application layer. Here, the application layer refers to a communication layer that performs communication for providing a service in an upper layer higher than the fifth layer in the OSI reference model. That is, the service providing unit 208 controls communication for providing services such as a printing function, an image streaming function, and a file transfer function to other communication devices, and controls the service execution unit 110.

  Reference numeral 209 denotes a service utilization unit in the application layer. Controls communication related to a service provided from a partner apparatus by communication using an application layer. That is, the service using unit 209 controls a function of transmitting a printed matter to the print service providing apparatus, a function of transmitting a moving image to the digital display, and the like, and controls the service execution unit 110. The error processing unit 210 performs error processing when the service cannot be executed.

  All the functional blocks have a mutual relationship in terms of software or hardware. Further, the functional block is an example, and a plurality of functional blocks may constitute one functional block, or any functional block may be further divided into blocks that perform a plurality of functions. The functional block may be realized by hardware.

  Subsequently, an operation in the communication apparatus having the above-described configuration will be described. FIG. 3 is a diagram showing a network A31 (hereinafter referred to as network A) composed of a communication device A32 (hereinafter referred to as STA-A) and a communication device B33 (hereinafter referred to as STA-B). These apparatuses have the configuration shown in FIGS. 1 and 2 described above.

  FIG. 4 is an operation flowchart of the communication apparatus which is a service using apparatus. The operation flow of the communication apparatus from service search to service use will be described with reference to this flowchart.

  First, the Service Discovery control unit 204 starts a service search process (service discovery) in the wireless LAN layer (S401). The Service Discovery control unit 204 transmits an SD Query and waits for reception of an SD Response. That is, the Service Discovery control unit 204 executes a first detection process for detecting a service executable by another communication device based on communication in the first communication layer. Next, the Service Discovery control unit 204 determines whether there is another communication device that can provide a desired service by service search (S402). This determination is made based on whether or not a response indicating that the desired service can be executed is received for the SD Query. In S402, when no SD Response is received, it is determined that a response indicating that the service can be provided has not been received. In addition, when the information indicating that the desired service can be provided cannot be detected in the information included in the SD Response, the Service Discovery control unit 204 determines that a response indicating that the desired service can be provided has not been received. Note that if another communication apparatus that has received the SD Query transmitted by the Service Discovery control unit 204 does not support the service discovery function (predetermined function) that is an optional function, the other communication apparatus does not respond.

  If it is determined in S402 that a response indicating that the desired service can be provided has not been received, the Wi-Fi Direct control unit 203 performs wireless connection processing (S405). In the wireless connection process in S405, a P2P group is formed with another communication apparatus in accordance with the Wi-Fi Direct specification, and a connection in the wireless LAN layer and the IP layer is established. That is, the Wi-Fi Direct control unit 203 executes a scanning process of the counterpart device, a role determination process of GO or CL, and a communication parameter sharing process in accordance with the Wi-Fi Direct specification.

  In S405, the Discovery control unit 202 can search for surrounding communication devices. Furthermore, it is possible to specify a service providing apparatus by allowing the user to select a connection partner from a list of search results. Further, the connection partner may be specified by using other methods. The Wi-Fi Direct control unit 203 determines whether or not the wireless connection with the other communication apparatus is successful in the wireless connection process in S405 (S406). For example, if there is no other communication device in the range where wireless communication is possible, the wireless connection process fails. If the wireless connection process fails in S407, the process proceeds to S409.

  If the wireless connection process is successful in S406, the L3 Service DISCOVERY control unit 205 starts a service search (S407). The L3 Service DISCOVERY control unit 205 executes a second detection process for detecting an executable service of another communication device based on communication in a second communication layer different from the first communication layer. In this description, the L3 Service DISCOVERY control unit 205 performs service search processing in the second communication layer using the search communication protocol SSDP defined by UPnP. SSDP is an abbreviation for Simple Service Discovery Protocol. The L3 Service DISCOVERY control unit 205 sends a service search signal called M-Search of SSDP in order to check whether another communication apparatus connected to the connected network provides a desired service (for example, a print service). To do. Based on the result of the service search in the second communication layer, it is determined whether there is another communication device that can provide the desired service (S408). The L3 Service DISCOVERY control unit 205 performs the determination by examining whether or not there is a response to the M-Search and whether or not a service type that can be used when there is a response is included. If there is no other communication device that can provide the desired service or if the wireless connection fails (No in S406, No in S408), the error processing unit 210 performs error processing (S409). In the error process, the display unit 105 displays that there is no device that can provide the desired service, and the process ends with an error.

  If there is another communication device that can provide a desired service (Yes in S408), the service using unit 209 starts the service using the acquired service information (S404).

  On the other hand, if it can be confirmed in the service search process in the wireless LAN layer that there is another communication apparatus that can provide the desired service in S402, the wireless connection process is performed in the same manner as in S405 (S403). However, in S403, since the service providing apparatus can be specified by the service search, the selection by the user can be omitted. For example, since the MAC address (identification information) of the service providing device can be acquired by service search, by limiting the connection partner to the same MAC address, the connection partner is autonomously limited to the service providing device searched in S402. It is possible.

  When the connection is completed, the service is started based on the service information obtained by the service search in S401 (S404).

  As described above, even when a service search response cannot be received from another communication device that does not support service discovery, which is an optional function, it corresponds to Wi-Fi Direct that exists in the communicable range. Wireless connection processing is performed with other communication devices. Then, a service search process defined by UPnP is performed, and it can be confirmed that another communication apparatus can execute the desired service, so that the desired service can be executed. In other words, since there is no response for service discovery in the wireless LAN layer, the process for executing the service is not terminated, so that the possibility of detecting another device that can execute the desired service can be improved.

  Note that the service using device and the service providing device in the present embodiment are the service printing services to be executed, the beneficiary device is the device having the image and document to be printed, and the providing device has the printing function. It is a device that has. That is, the former is a digital camera or a smartphone, and the latter is a printer. In the case of a video streaming service, the beneficiary device is a video recording device such as a digital camera or a camcorder, and the providing device is an image display device such as a digital TV or a projector. If the service to be executed is DLNA (registered trademark), for example, the service using device is a DMS (digital media server), and the service providing device is a DMR (digital media renderer). DLNA is an abbreviation for Digital Living Network Alliance. Note that this description is an example because various device classes exist in the DLNA standard. Refer to the DLNA standard for details.

  Subsequently, an operation sequence between the apparatuses in the present embodiment will be described with reference to sequence diagrams shown in FIGS. In FIG. 5, a case where STA-B is a service X providing apparatus, STA-A is a service X beneficiary apparatus, and both STA-A and STA-B support the service discovery function will be described as an example.

  In FIG. 5, the STA-A 32 transmits an SD Query to detect other communication apparatuses that can execute the service X using the service discovery function (F501). In this example, the STA-A 32 transmits an SD Query specifying the service X. The SD Query can be transmitted by unicast, or can be transmitted by broadcast or multicast. Since the STA-B 33 supports the service discovery function, when receiving the SD Query, the STA-B 33 transmits an SD Response indicating that the service X can be provided to the STA-A 32 (F502). Note that service information indicating that a service other than the service X is supported may be added to the SD Response.

  The STA-A 32 determines that the STA-B 33 can provide the service X by receiving the response to the transmitted SD Query from the STA-B 33. Then, the STA-A 32 performs wireless connection processing in accordance with the specifications of STA-B and Wi-Fi Direct (F503). By this processing, the STA-A 32 and the STA-B 33 are in a state where the connection and the IP setting in the wireless LAN are completed.

  When the wireless connection process with the STA-B 33 is completed, the STA-A 32 starts the service X based on the service information acquired by the service search (F504). Specifically, when the service X is a printing service, when printing an image taken by the STA-A 32, a printer (STA-B 33) having a printing function is searched, and a captured image is obtained via wireless. A printing process for printing on the STA-B 33 is performed.

  Subsequently, in FIG. 6, STA-B33 is a service X providing device, STA-A32 is a service X beneficiary device, STA-A32 supports a service discovery function, and STA-B33 supports a service discovery function. An example in the case where there is not will be described.

  In FIG. 6, the STA-A 32 transmits the SD Query in the same manner as F501 (F601). In this case, since the STA-B 33 does not support the service discovery function, the SD Response is not transmitted to the SD Query.

  Since the STA-A 32 does not receive the SD response, the STA-A 32 determines that there is no other communication device that can provide a desired service, and performs wireless connection processing without acquiring service information (F602). The STA-A 32 detects that the STA-B 33 is within a communicable range by a scanning process, and performs a wireless connection with the STA-B 33.

  When the wireless connection process is completed, the STA-A 32 starts a service search in a second communication layer different from the first communication layer (F603). In this example, the STA-A 32 transmits a service search request specifying the service X (F603). Since the STA-B 33 supports the service search function in the second communication layer, when receiving the service search request, the STA-B 33 transmits a service search response indicating that the service X can be provided to the STA-A 32 (F604). ). Upon receiving the L3 service search response, the STA-A 32 starts the service X based on the assigned service information (F605).

  As described above, according to the present embodiment, it is possible to start a service regardless of whether other communication apparatuses capable of executing a desired service support the service discovery function. In addition, when it is detected by the service discovery function that another communication device can execute the desired service, the service search process in the other communication layer is not executed, so the time until the service start can be shortened. User convenience is improved. The wireless connection process is also performed when a service search response cannot be received from another communication device that does not support service discovery, which is an optional function. Then, service search processing defined in a communication layer different from the wireless LAN communication layer such as UPnP is performed, and it can be confirmed that other communication devices can execute the desired service, so that the desired service can be executed. Become. In other words, since there is no response for service discovery, the process for executing the service is not terminated, so that the possibility of detecting another device that can execute the desired service can be improved.

  In the above example, the service search using the SD Query / SD Response is exemplified. However, a search signal such as a Probe Request / Probe Response may be used for the service search process. For example, the service search process can be executed by adding an Information Element (IE) indicating that a desired service can be executed to the Probe Request / Probe Response.

  In the above-described example, an example in which the service using device performs the service search has been described. However, the present invention can be applied even when the service providing device performs the service search.

(Example 2)
In the first embodiment, an example has been described in which a service search using the service detection function is performed before wireless connection with another communication apparatus. In the second embodiment, after a wireless connection with another communication apparatus, a service search by a service detection function is executed. If the connection partner does not support the service detection function, an example of executing service search processing in the second communication layer will be described. The configuration of each apparatus is as shown in FIGS. 1 and 2 as in the first embodiment.

  An operation flowchart of the service using apparatus according to the second embodiment will be described with reference to the flowchart shown in FIG. In the flowchart shown in FIG. 7, an example in which an execution instruction for service Y is received in a state in which a network with another communication apparatus has already been established in order to execute service X will be described.

  In FIG. 7, the communication apparatus starts processing when connection with the communication partner via the wireless LAN and IP setting are completed and an execution instruction for service Y is received in a state where another service is being executed or after execution. When the service Y execution instruction is received, the service discovery control unit 204 starts a service search by the service discovery function (S701). The Service Discovery control unit 204 transmits an SD Query specifying the service Y, and waits for reception of an SD Response. In S701, SD Query / SD Response may be used for service search, and Probe Request / Probe Response may also be used.

  Next, similarly to S402, it is determined whether the connection partner can provide a service (S702). If it is determined in S702 that a response indicating that a desired service can be provided has not been received, a service search in the second communication layer is started (S704). The L3 Service DISCOVERY control unit 205 determines whether the connection partner can provide a desired service based on the service search result in the second communication layer (S705). If it is determined in S705 that the desired service cannot be provided, error processing is performed (F706). In the error processing in F706, the display unit 105 displays that the connection partner cannot execute the desired service, and the processing ends in error.

  If it is determined in S705 that the desired service can be provided, the service is started with the connection partner in the same manner as in S404 based on the acquired service information (S703).

  Specifically, an operation such as starting a file transfer service and transferring a file while displaying a video with a video streaming service is possible. It should be noted that the specific examples here are not intended to limit the invention, but are merely examples for deepening understanding.

  Subsequently, an operation sequence of each apparatus in the present embodiment will be described with reference to sequence diagrams shown in FIGS. In FIG. 8, STA-B 33 is a service X and service Y providing device, STA-A 32 is a service X and service Y beneficiary device, and both STA-A and STA-B support the service discovery function. It is an example. STA-A and STA-B will first describe the operation example when starting service X and then starting service Y.

  Since F801 to F804 are the same as F501 to F504, description thereof is omitted. With these processes, the STA-B 33 provides the service X to the STA-A 32. Next, in the STA-A 32, when execution of the service Y is instructed, an SD Query specifying the service Y and requesting the service Y is transmitted (F805). Since the STA-B 33 supports the service discovery function, when receiving the SD Query, the STA-B 33 transmits an SD Response indicating that the service Y can be provided to the STA-A 32 (F806). When receiving the SD Query, the STA-A 32 starts the service Y based on the acquired service information (F807). As described above, another service Y can be started in the network constructed for executing the service X.

  Next, in FIG. 9, a case where the STA-B 33 is a service X and service Y providing device, the STA-A 32 is a service X and service Y beneficiary device, and the STA-A 32 supports the service discovery function will be described. . An example in which the STA-B 33 does not support the service discovery function will be described. Further, STA-A and STA-B will be described with reference to an operation example when service X is started first and service Y is subsequently started.

  Since F901 to F905 are the same as F601 to F605, description thereof will be omitted. With these processes, the wireless connection is completed and the STA-B 33 is in a state of providing the service X to the STA-A 32. Next, in the STA-A 32, when execution of the service Y is instructed as in F805, an SD Query specifying the service Y and requesting the service Y is transmitted (F906). However, since STA-B does not support the service discovery function, it does not transmit an SD Response to the SD Query.

  Since the STA-A 32 does not receive the SD Response, the STA-A 32 subsequently starts a service search in a second communication layer different from the first communication layer (F907). Since the STA-B 33 supports the service search function in the second communication layer, when the service search request is received, a service search response indicating that the service Y can be provided is transmitted to the STA-A 32 (F908). When receiving the L3 service search response, the STA-A 32 starts the service Y based on the assigned service information (F909).

  Here, the case where the SD Query is transmitted again at the start of the service Y has been described as an example, but the fact that the service search of the service X has failed is stored in the storage unit 103, and the search by the SD Query is omitted. It is also possible. In particular, when performing a search without designating a service in service discovery in the wireless LAN layer of service X, if there is no response from the counterpart device, the counterpart device may not support service discovery in the wireless LAN layer. . Therefore, in this case, the service search in the second communication layer may be performed without transmitting the SD Query again when the service Y is started.

  As described above, according to the present embodiment, it is possible to start a service regardless of whether or not the service discovery function of the opposite device is supported even in a state where a network has already been constructed.

(Example 3)
In the third embodiment, a service search by the service detection function is executed after wireless connection with the other communication apparatus described in the second embodiment. If the connection partner does not support the service detection function, the second communication is further performed. Another example of executing the service search process in the layer will be described. The configuration of each apparatus is as shown in FIGS. 1 and 2 as in the first embodiment. FIG. 12 is a system configuration diagram in the present embodiment. In FIG. 12, there are a communication device A32 (hereinafter, STA-A), a communication device B33 (hereinafter, STA-B), and a communication device C34 (hereinafter, STA-C).

  FIG. 13 is an operation flowchart of the STA-A 32 in this embodiment. The operation flow of the communication apparatus from service search to service use will be described with reference to this flowchart.

  First, the Discovery control unit 202 searches for wireless communication devices in a communicable range (S1301). In the search processing in S1301, first, all channels are scanned based on the Wi-Fi Direct protocol specification. Then, scanning of a predetermined channel (social channel) and waiting for a probe request from another device on the predetermined channel are repeated to search for a partner device. The Wi-Fi Direct control unit 203 performs wireless connection processing with the counterpart device searched in S1301 (S1302). In S1303, the STA-A 32 performs communication in the network constructed in S1302 (S1303).

  Note that the process of S1303 may be omitted. The STA-A 32 determines whether a service execution instruction is received from the user after the network construction (S1304). In S1304, when a service execution instruction is received from the user, the Service Discovery control unit 204 starts a service search process (service discovery) in the wireless LAN layer (S1305). The Service Discovery control unit 204 broadcasts the SD Query and waits for reception of the SD Response. Next, the Service Discovery control unit 204 determines whether there is a response indicating that a desired service can be provided from the partner apparatus wirelessly connected in S1302 (S1306). Further, identification information of other apparatuses that can execute a desired service existing in the vicinity from the broadcast SD Query response is stored.

  If it is determined in S1306 that a response indicating that the desired service can be provided has not been received from the connection partner, the L3 Service DISCOVERY control unit 205 starts a service search (S1308). In this description, the L3 Service DISCOVERY control unit 205 performs service search processing in the second communication layer using the search communication protocol SSDP defined by UPnP. Based on the result of the service search in the second communication layer, it is determined whether the connection partner can provide a desired service (S1309). The L3 Service DISCOVERY control unit 205 performs the determination by examining whether or not there is a response to the M-Search and whether or not a service type that can be used when there is a response is included. If the connection partner does not support the desired service, the wireless connection with the connection partner is disconnected (leaves from the network, leaves the group), and the Discovery control unit 202 again sets a wireless communication device within a communicable range. Search is performed (S1310). If another communication apparatus capable of executing a desired service has been detected by the service detection broadcast in S1305, a probe request designating the other communication apparatus may be transmitted.

  The Wi-Fi Direct control unit 203 performs wireless connection processing with another communication device different from the partner connected to S1302 searched in the search processing of S1310 (S1311). The L3 Service DISCOVERY control unit 205 starts a service search for the other party connected in S1311 (S1312). Based on the result of the service search in the second communication layer in S1311, it is determined whether there is another communication device that the partner device connected in S1312 can provide a desired service (S1314). If the connection partner can provide the desired service, the service using unit 209 starts the service using the acquired service information (1307). If the connection partner cannot provide the desired service, error processing is performed (S1313). In the error process, the display unit 105 displays that there is no device that can provide the desired service, and the process ends with an error. If the connection partner can provide a desired service in S1305, the service using unit 209 starts the service (S1307).

  With the above processing, it is possible to detect whether the connection partner can execute a desired service when a service execution is instructed after the wireless network is constructed. Further, when the connection partner cannot execute the desired service, the service can be executed by wirelessly connecting to another communication apparatus that can execute the desired service in the vicinity.

  Subsequently, an operation sequence of each apparatus will be described in the third embodiment with reference to sequence diagrams shown in FIGS. 10 and 11. In FIG. 10, STA-B33 is a service X providing device, STA-A32 is a service X beneficiary device, STA-A32 supports the service discovery function, and STA-B33 does not support the service discovery function. Will be explained. Further, STA-A 32 and STA-B 33 will first describe a case where an instruction to execute service X is received after a network is constructed by connection processing based on the Wi-Fi Direct protocol specification.

  In FIG. 10, the STA-A 32 constructs a network with the STA-B 33 by connection processing based on the Wi-Fi Direct protocol specification (F1001), and executes normal communication processing (F1002). A network A31 shown in FIG. Next, when the execution of service X is instructed in STA-A 32 (F1003), an SD Query requesting service X specifying service X is transmitted (F1004). Since the STA-B 33 does not support the service discovery function, the STA-B 33 does not transmit an SD Response to the SD Query.

  Since the STA-A 32 does not receive the SD Response, the STA-A 32 subsequently starts a service search in a second communication layer different from the first communication layer (F1005). Since the STA-B 33 supports the service search function in the second communication layer, when the service search request is received, a service search response indicating that the service Y can be provided is transmitted to the STA-A 32 (F1006). When the STA-A 32 receives the L3 service search response, the STA-A 32 starts the service Y based on the assigned service information (F1007).

  Here, the case where the SD Query is transmitted again at the start of the service Y has been described as an example, but the fact that the service search of the service X has failed is stored in the storage unit 103, and the search by the SD Query is omitted. It is also possible.

  Next, an example in which STA-C is a service X providing apparatus, STA-A 32 is a service X beneficiary apparatus, and STA-A 32 supports the service discovery function in FIG. 11 will be described. An example in which the STA-B 33 does not support the service discovery function and the service X will be described. Further, STA-A 32 and STA-B 33 will first describe a case where an instruction to execute service X is received after a network is constructed by connection processing based on the Wi-Fi Direct protocol specification.

  In FIG. 11, the STA-A 32 constructs a network with the STA-B 33 by connection processing based on the Wi-Fi Direct protocol specification (F1101), and executes normal communication processing (F1102). A network A31 shown in FIG. Next, when the execution of the service X is instructed in the STA-A 32 (F1103), an SD Query specifying the service X and requesting the service X is broadcast (F1104). Since the STA-B 33 does not support the service discovery function, the STA-B 33 does not transmit an SD Response to the SD Query. Also, since STA-C does not support the service discovery function, the SD Response is not transmitted to the SD Query.

  Since the STA-A 32 does not receive the SD Response, the STA-A 32 subsequently starts a service search in the second communication layer different from the first communication layer (F1105). Since the STA-A 32 is constructing a network with the STA-B 33, the service search function in the second communication layer can be performed only for the connected communication partner apparatus. However, since the STA-B 33 that currently belongs to the same group does not support the service X, even if a service search request is received, no response is returned. The STA-A 32 determines that there is no device capable of executing a desired service in the currently connected network, and executes a disconnection process for the currently connected network (F1106). Subsequently, in order to connect to another communication apparatus (here, STA-C) that can communicate, wireless connection processing including scanning processing of the partner apparatus is performed in accordance with the Wi-Fi Direct specification (F1107). In this example, the STA-C is searched by the scanning process, and the STA-A 32 newly constructs a network with the STA-C. A network B35 shown in FIG. 12B is constructed. Note that the STA-A 32 determines that the STA-C does not support the service discovery function because the response of the signal used for service discovery in the wireless LAN layer transmitted by F1104 has not been received from the STA-C. Since the STA-A 32 determines that the STA-C does not support the service detection function, the STA-A 32 starts a service search in a second communication layer different from the first communication layer (F1108).

  Since STA-C supports the service search function in the second communication layer, when receiving the service search request, STA-C transmits a service search response indicating that service X can be provided to STA-A 32 (F1109). When the STA-A 32 receives the L3 service search response, the STA-A 32 starts the service Y based on the assigned service information (F1109).

  Here, the case where the SD Query is not transmitted before the wireless connection in F1107 has been described as an example, but it is also possible to perform a search using the SD Query again before the wireless connection in F1107.

  As described above, according to the present embodiment, in a state where a network is already constructed, it is possible to search for a communication partner capable of executing a desired service even when the connection partner does not support the desired service. . Further, it is possible to search for a communication partner capable of executing a desired service regardless of whether or not the connection partner supports a desired service discovery function.

(Other examples)
In the above-described embodiment, the example in which the service search process, the wireless connection process, and the L3 service search process are sequentially performed has been described. However, these processes may be performed in parallel. For example, if the service providing apparatus cannot be found even after the service search process is initially performed for a certain period of time, the service search process may be performed in parallel with the subsequent wireless connection process or the L3 service search process. When a desired service search response is received in the service search process executed in parallel, the service can be started by omitting or interrupting the L3 service search process.

  If the host application needs service information (such as an IP address) acquired by the L3 service search process, it is possible to omit the service search process and start the wireless connection process and the L3 service search process. Further, when the connection partner can recognize in advance by the user's instruction or the like that the device does not support the service search function, the same countermeasure can be taken.

  Further, when the service information acquired by the host application by the service search process is required, an error display or the like may be performed when the desired service search response cannot be received by the service search process.

  According to the present invention, a recording medium recording software program codes for realizing the above-described functions is supplied to a system or apparatus, and a computer (CPU, MPU) of the system or apparatus reads and executes the program codes stored in the recording medium. It may be. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, a DVD, or the like is used. it can.

  Further, by executing the program code read by the computer, not only the above-described functions are realized, but also the OS running on the computer based on an instruction of the program code partially or entirely of the actual processing. To realize the above-described function. OS is an abbreviation for Operating System.

  Further, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instruction of the program code, the CPU provided in the function expansion board or function expansion unit may perform part or all of the actual processing to realize the above-described function.

31 Network A
32 STA-A
33 STA-B

Claims (18)

A communication device,
First detection means for detecting another communication device capable of executing a predetermined service based on communication in the first communication layer after establishing a wireless network with the first other communication device;
If the first other communication device is not detected by the first detection unit, the first detection unit is configured to perform communication based on communication via the wireless network in a second communication layer different from the first communication layer. Second detection means for detecting an executable service of another communication device;
If the second other communication device cannot detect that the predetermined service is executable by the second detection means, the wireless network constructed with the first other communication device is terminated. Construction means for constructing a wireless network with the second other communication device detected by the first detection means;
A communication apparatus comprising:   When the response to the service search signal transmitted in the first communication layer cannot be detected from the first other communication device, the second detection means, based on the communication in the second communication layer, The communication apparatus according to claim 1, wherein an executable service of one other communication apparatus is detected.   The first detection means detects an executable service of the first other communication device based on information included in a response to the service search signal transmitted in the first communication layer. The communication device according to claim 1 or 2.   The second detection means detects an executable service of the first other communication device based on information included in a response to the service search signal transmitted in the second communication layer. The communication apparatus according to any one of claims 1 to 3.   When the first detection unit or the second detection unit detects that the first other communication device can execute a predetermined service, the first detection unit and the second detection unit The communication apparatus according to any one of claims 1 to 4, wherein the service is executed.   2. The detection by the second detection unit is not performed when the first other communication device detects that the predetermined service is executable by the first detection unit. The communication device according to any one of 1 to 5.   The communication apparatus according to claim 1, further comprising a storage unit that stores identification information of another communication apparatus detected by the first detection unit.   8. The wireless communication apparatus according to claim 1, wherein the predetermined service is executed with the second other communication apparatus after a wireless network is established with the second other communication apparatus by the construction means. The communication device according to item.   The first detection unit is another communication device capable of executing the predetermined service when the user is instructed to execute the predetermined service after establishing a wireless network with the first other communication device. The communication device according to claim 1, wherein the communication device is detected.   The first detection means detects another communication device capable of executing the predetermined service based on communication in the data link layer of the OSI reference model, which is the first communication layer. The communication apparatus according to any one of claims 1 to 9.   The first detection means detects another communication apparatus capable of executing the predetermined service by using a generic advertisement service frame, a probe request, or a probe response defined in IEEE802.11u. The communication apparatus according to any one of 1 to 8.   The said 1st detection means detects the other communication apparatus which can perform the said predetermined | prescribed service based on Wi-Fi Direct (trademark), The any one of Claim 1 thru | or 11 characterized by the above-mentioned. The communication apparatus as described in.   The second detection means detects an executable service of the first other communication device based on communication in the network layer in the OSI reference model, which is the second communication layer. The communication apparatus according to any one of claims 1 to 12.   11. The second detection unit detects an executable service of the first other communication device based on Universal Plug and Play or Bonjour (registered trademark). The communication apparatus according to claim 1.   The communication apparatus according to claim 1, wherein the communication apparatus constructs a wireless network based on the first other communication apparatus and Wi-Fi Direct (registered trademark). .   16. The communication apparatus according to claim 1, wherein the predetermined service is a print service, a data distribution service, or a moving image streaming service. A communication device control method comprising:
A first detection step of detecting another communication device capable of executing a predetermined service based on communication in the first communication layer after establishing a wireless network with the first other communication device;
If the first other communication device is not detected by the first detection step, the first communication device is based on communication via the wireless network in a second communication layer different from the first communication layer. A second detection step of detecting an executable service of another communication device;
If the first other communication device cannot detect that the predetermined service is executable in the second detection step, the wireless network constructed with the first other communication device is terminated. A construction step of constructing a wireless network with the second other communication device detected by the first detection step;
A control method for a communication apparatus, comprising:   A program for operating a computer as the communication device according to any one of claims 1 to 16.

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