JP2018078527A - Radio communication device, control method thereof, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain connection even if a group owner (GO) has disappeared in a P2P group.SOLUTION: A radio communication device functioning as an access point in a network including a plurality of radio communication devices selects a radio communication device that should function as an access point if the communication device functioning as the access point disappear from the network from the other radio communication devices in the network on the basis of the numbers of providing side radio communication devices of prescribed services and receiving side radio communication devices, and transmits prescribed information to take over the network to the selected radio communication device.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a wireless communication device, a wireless communication method, and a wireless communication system for performing wireless communication between wireless communication devices.

  In recent years, a technique for mirroring a display screen on another display by wireless communication has been standardized as Miracast (registered trademark) (Wi-Fi Display). Mirroring refers to the function of displaying the screen displayed on the display of one device on the display of the other device. The use of this technology is expanding as the proportion of standard support for OSs (Operating Systems) for smartphones and PCs (Personal Computers) increases. In Miracast, a device that transmits a display screen is called a source, and a device that receives and displays a screen is called a sink.

  As a wireless communication technology by Miracast, Wi-Fi Direct (registered trademark) is used. Wi-Fi Direct is a technology for easily wirelessly connecting a plurality of devices. A feature of Wi-Fi Direct is that it is not necessary to prepare a separate AP (access point) in addition to a device that performs wireless connection. For this reason, it is used in a simple connection field such as connection between smartphones or between a smartphone and a printer.

  In a network (P2P (Peer-to-Peer) group) compliant with Wi-Fi Direct, any one of wirelessly connected devices plays a role as an AP instead of separately requiring an AP. Such a device that plays the role of AP is called GO (Group Owner (base station)), and a STA (Station) device other than AP is called CL (Client). The GO acts as an AP in the P2P group and has various responsibilities as an AP. The responsibilities as the AP include, for example, transmitting a beacon and authenticating a connection with the STA (CL). On the other hand, CL behaves as an STA in the P2P group. Further, the GO has a duty as a Dynamic Host Configuration Protocol (DHCP) Server, and the CL has a duty as a DHCP Client. Thereby, the CL can determine its own IP address (hereinafter referred to as IP addressing).

  With Wi-Fi Direct, it is possible to connect three or more devices. When connecting three devices, as a general procedure, connection is first made between the two devices. When two devices are connected by Wi-Fi Direct, a procedure called Group Owner Negotiation is often performed in order to determine which device plays the role of GO. By this procedure, a device that is expected to become more GO from the two devices is selected as GO. Subsequently, a third device joins / connects to the P2P group to form a P2P group of three devices. At this time, generally, the role of GO is not changed by three devices, and the third device is always CL. Therefore, when a P2P group is constructed with three or more devices, communication between other CLs becomes impossible when the GO disappears for some reason. Note that the disappearance of GO means that the GO can no longer function as an AP due to a cause such as a power failure of the GO or radio wave interruption.

  A problem when three devices are connected by Wi-Fi Direct will be described with reference to FIG. FIG. 8 is a schematic diagram illustrating a configuration before and after the disappearance of GO in the prior art. In FIG. 8A, a P2P group is configured by three units of Source A (CL) 801, Sink A (GO) 802, and Sink B (CL) 803. With such a configuration, the Sink A (GO) 802 may disappear for some reason. At this time, the wireless connection between the remaining CLs (that is, Source A (CL) 801 and Sink B (CL) 803) is disconnected (FIG. 8B). In this case, it is necessary for another device to substitute for GO. As a proxy / transfer technique for GO, for example, there are techniques described in Patent Documents 1 and 2.

  In Patent Document 1, a wireless communication device determines a wireless communication device that plays the role of the next base station (GO) according to a base station index (an index that matches a function as a base station of a network). It is described that the function of a base station is transferred to a wireless communication apparatus. The base station (GO) transfers the role of the base station (GO) to the CL (wireless communication device) in advance before disappearance, so that the remaining CL (wireless communication device) can continue communication. .

  Patent Document 2 describes that a coordinator in a wireless PAN transfers the role of the coordinator to another terminal under specific conditions. The coordinator selects candidates for the coordinator transfer in advance, so that the coordinator can be transferred quickly in an emergency.

JP 2013-38724 A US Patent Application Publication No. 2005/0237979

  Since the method of the above literature transfers the role of GO during the validity period of the P2P group, the role of GO cannot be transferred after detecting the disappearance of GO. For example, when communication disconnection, battery exhaustion, or outlet disconnection due to changes in the radio wave environment occur, the GO cannot transfer the role of GO to another wireless communication device, and the P2P group is canceled. In the above document, the role of the Miracast device is not considered. For example, in a P2P group with one source and five sinks, there is a possibility of selecting one of the sinks as a transfer destination of the role of GO. In such a case, the P2P group is canceled when the sink that is the transfer destination disappears.

  The present invention has been made in view of the above problems, and an object of the present invention is to maintain a connection even when GO is lost in a P2P group.

  In order to achieve the above object, a wireless communication apparatus according to an aspect of the present invention has the following arrangement. That is, in a network composed of a plurality of wireless communication devices, a wireless communication device functioning as an access point, and a wireless communication device on the providing side of a predetermined service and reception from other wireless communication devices in the network Selection means for selecting a wireless communication device to function as the access point when the communication device functioning as the access point disappears from the network based on the number of wireless communication devices on the side, and the selected wireless communication Transmitting means for transmitting predetermined information for taking over the network to the apparatus.

  According to the present invention, it is possible to maintain a connection even when GO is lost in a P2P group.

The figure which shows the structure of the radio | wireless communication apparatus in embodiment. The flowchart for demonstrating the process of the radio | wireless communication apparatus as GO in 1st Embodiment. The flowchart for demonstrating the process of the radio | wireless communication apparatus as CL in 1st Embodiment. The sequence diagram for demonstrating the operation | movement in 1st Embodiment. Schematic explaining the configuration before and after the disappearance of GO in the second embodiment. The figure which shows the conditions for GO in 2nd Embodiment to determine Secondary GO. 9 is a flowchart for explaining processing of a wireless communication apparatus as a GO in the second embodiment. Schematic explaining the structure before and after the disappearance of GO in the prior art.

  Hereinafter, the present invention will be described in detail based on the embodiments with reference to the accompanying drawings. The configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

[First Embodiment]
A configuration example of the wireless communication apparatus 100 according to the first embodiment will be described with reference to FIG. FIG. 1A illustrates a hardware configuration example of the wireless communication apparatus 100, and FIG. 1B illustrates a functional configuration example of the wireless communication apparatus 100.

  First, the hardware configuration of the wireless communication apparatus 100 will be described. In FIG. 1A, the storage unit 101 includes a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory). The storage unit 101 stores various information such as a program for performing various operations described later and communication parameters for wireless communication. In addition to the memory such as ROM and RAM, the storage unit 101 is a storage medium such as 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, and a DVD. May be used. The storage unit 101 may include a plurality of memories.

  The control unit 102 includes a processor such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit). The control unit 102 controls the entire wireless communication apparatus 100 by executing a program stored in the storage unit 101. Further, the control unit 102 may include a plurality of processors such as multi-cores, and the plurality of processors may control the entire wireless communication apparatus 100.

  The input unit 103 accepts various operations from the user. The output unit 104 includes a liquid crystal monitor and the like, and performs various displays. Note that both the input unit 103 and the output unit 104 may be realized by one module like a touch panel. Further, the output unit 104 may be configured to perform other than display.

  The communication unit 105 controls wireless communication as an interface for connecting to a wireless LAN (Local Area Network). In addition, the communication unit 105 controls the antenna 106 to transmit / receive a wireless signal for wireless communication. The wireless communication apparatus 100 can also transmit content such as video data to the opposite device via the communication unit 105.

  Next, a functional configuration of the wireless communication device 100 will be described. In FIG. 1B, the wireless communication control unit 111 includes a GO (Group Owner) control unit 112, a CL (Client) control unit 113, and a P2P Role switching control unit 114 in order to manage the connection of the wireless LAN. The GO control unit 112 has a function as a wireless LAN AP (access point, that is, GO or base station mode), and controls connection with STAs (Stations) of other wireless LANs. In addition, the GO control unit 112 manages information necessary for connection with STAs of other wireless LANs (for example, encryption information necessary for encryption). The CL control unit 113 has a function as a wireless LAN STA (that is, CL or normal mode), and controls connection with other wireless LAN APs. The P2P Role switching control unit 114 can switch the operation of the wireless communication control unit 111 between control by the GO control unit 112 (base station mode) and control by the CL control unit 113 (normal mode) at an arbitrary timing. It is.

  The DHCP server control unit 115 has a function (network control function) as a dynamic host configuration protocol (DHCP) server. The DHCP server control unit 115 manages network information including address information. For example, the DHCP server control unit 115 lends an IP address to each device and manages the lent IP address in response to a request from another DHCP client. The DHCP Client control unit 116 has a function as a DHCP Client. The DHCP Client control unit 116 sets its own IP address by sending an IP address lending request to the DHCP Server. Further, when the lending time limit of the IP address becomes less than a certain value, the DHCP Client control unit 116 transmits a request for extending the lending time limit of the IP address to the DHCP server.

  The display device control unit 117 performs control for displaying the video and / or audio information received from the codec control unit 118 on the output unit 104. When the wireless communication apparatus 100 operates as a source (a predetermined service providing side), the codec control unit 118 acquires uncompressed video and / or uncompressed audio information and compresses the information. Further, when the wireless communication apparatus 100 is operating as a sink (a predetermined service receiving side), the codec control unit 118 acquires the compressed video and / or compressed audio information received from the opposite device and decompresses the information. Do.

  The video communication control unit 119 performs control for communicating the compressed video and / or compressed audio information subjected to the compression processing by the codec control unit 118 with the opposite device. The GO loss detection unit 120 operates when the CL control unit 113 is operating in the wireless communication control unit 111. The GO loss detection unit 120 monitors the presence of a GO that the wireless communication apparatus 100 is connected to, and notifies the P2P Role switching control unit 114 when it has confirmed the loss of the GO.

  The secondary GO selection unit 121 operates when the wireless communication apparatus 100 is operating as a GO. The secondary GO is a CL that should become a new GO when the disappearance of the GO is detected (a CL that has become an alternative candidate for GO). The Secondary GO selection unit 121 selects (determines) the Secondary GO based on the number of Source / Sinks in the P2P group acquired from the other device management unit 123 described later. Further, the secondary GO selection unit 121 receives network information including address information and information necessary for connection as takeover information from the DHCP server control unit 115 and the GO control unit 112 of the wireless communication control unit 111, and receives the wireless communication control unit 111. Then, the takeover information is transmitted to the CL.

  The takeover information management unit 122 operates when the wireless communication apparatus 100 is operating as a Secondary GO. The takeover information management unit 122 holds the takeover information when the takeover information is received from the GO. The other device management unit 123 acquires and manages information on the wireless communication devices in the P2P group. For example, the other device management unit 123 measures the number of Sources / Sinks. The measured value is used by the secondary GO selection unit 121 to select the secondary GO. Note that the Source / Sink determination includes, for example, a method of confirming a WFD IE (Wi-Fi Display Information Element) of a wireless frame transmitted by the wireless communication apparatus 100. Specifically, the WFD Device Info Descriptor field of the WFD Session Subscriber included in the WFD IE is referred to. Moreover, you may use methods other than the method of confirming said WFD IE.

  Next, the operation of the wireless communication apparatus 100 will be described with reference to FIGS. FIG. 2 shows the operation of the wireless communication apparatus 100 as GO, and FIG. 3 shows the operation of the wireless communication apparatus 100 as CL. In this description, as shown in FIG. 8 described as the prior art, a wireless communication system (P2P group (for example, Wi-Fi) including three units of Source A (CL) 801, Sink A (GO) 802, and Sink B (CL) 803). -A network conforming to Fi Direct))).

  In FIG. 2, in order for Sink A (GO) 802 to prepare for its own disappearance, a candidate (Secondary GO) that plays the role of GO is selected from CL (STA), and the takeover information of GO is transmitted to the Secondary GO It is a flowchart explaining a process.

  In step S201, the secondary GO selection unit 121 of the sink A (GO) 802 selects a secondary GO from the devices in the P2P group. When Sink A (GO) 802 loses the role of GO, two units of Source A (CL) 801 and Sink B (CL) 803 exist in the P2P group. At that time, the secondary GO selection unit 121 of the sink A (GO) 802 selects either the source A (CL) 801 or the sink B (CL) 803 as the secondary GO. For this selection, certain elements may be consulted. For example, the predetermined element includes information on the battery of the device (for example, the remaining battery capacity of the device, a power supply method for the device), information indicating the likelihood of becoming a GO (for example, GO Intent value), radio wave intensity, Secondary GO function ( Presence / absence of a function for becoming a GO using the takeover information. Here, the secondary GO selection unit 121 of the sink A (GO) 802 selects the sink B (CL) 803 as the secondary GO, and the process proceeds to step S202.

  In step S202, the GO control unit 112 of the sink A (GO) 802 transmits the takeover information of the P2P group to the sink B (CL) 803 of the secondary GO determined in step S201 via the communication unit 105. This transmission may be performed again after a predetermined time has elapsed (that is, it may be transmitted a plurality of times). The P2P group takeover information includes, for example, encryption information (encryption key, password, passphrase, PSK) necessary for encryption, address information (IP address, IP address expiration date, IP address lease information). (Information on lease period) etc.). Further, the GO control unit 112 can use UDP (User Datagram Protocol) or P2P Action Frame when transmitting takeover information of the P2P group.

  Note that the processing of the flowchart shown in FIG. 2 can be executed when the configuration of the P2P group changes. For example, when a new device is added, or when a certain device constituting the P2P group leaves the P2P group. Further, when the takeover information of the P2P group is changed or updated, such as when the expiration date of the IP address is extended, the wireless communication device 100 as the GO executes the processing of this flowchart and transmits the takeover information. Good.

  Also, the secondary GO selection unit 121 of the sink A (GO) 802 may cancel the secondary GO once determined and select another secondary GO. In this case, the GO control unit 112 of the Sink A (GO) 802 may send the takeover information to the newly selected Secondary GO. In this case, the GO control unit 112 of the Sink A (GO) 802 sends a takeover information deletion request via the communication unit 105 to notify the canceled Secondary GO that a new Secondary GO has been selected. Can be sent.

  FIG. 3 is a flowchart for explaining processing until the Secondary GO Sink B (CL) 803 determined in step S201 in FIG. 2 receives the takeover information from the GO and becomes GO (starts the role of GO).

  In step S301, the takeover information management unit 122 of the SinkB (CL) 803 determines whether or not the P2P group takeover information from the GO is received via the communication unit 105. When the sink B (CL) 803 receives the takeover information, the sink B (CL) 803 recognizes that it has been selected as the Secondary GO. When the takeover information management unit 122 of the SinkB (CL) 803 determines that the takeover information has been received from the SinkA (GO) 802 (Yes in step S301), the CL control unit 113 monitors the disappearance of the SinkA (GO) 802. (Step S302). The CL control unit 113 monitors the disappearance of the Sink A (GO) 802 based on whether the beacon signal transmitted by the GO can be received for a certain period of time (for example, 800 ms) or more, or whether the radio wave intensity of the GO is below a certain level. . For example, when the CL control unit 113 has not received a beacon signal transmitted by the GO for a certain period of time or when it is determined that the radio wave intensity of the GO is below a certain level, the GO disappearance detection unit 120 performs the sink A (GO) The disappearance of 802 is detected (Yes in step S302). Then, the process proceeds to step S303.

  In step S303, the Sink B (CL) 803 starts the role as GO using the takeover information received in step S301. That is, the P2P Role switching control unit 114 of the SinkB (CL) 803 switches the operation of the wireless communication control unit 111 from control by the CL control unit 113 to control by the GO control unit 112 at an arbitrary timing. The DHCP server control unit 115 activates a function as a DHCP server.

  Note that the Sink A (GO) 802 re-selects the Secondary GO due to the reason that a device has been added to or deleted from the P2P group (when the number of devices has changed) after selecting the Sink B (CL) 803 as a Secondary GO. May choose. In such a case, the takeover information management unit 122 of the SinkB (CL) 803 receives the takeover information deletion request transmitted from the SinkA (GO) 802 and deletes the takeover information that has already been received. As a result, the Sink B (CL) 803 ends the operation (S302, S303) as the Secondary GO.

  Further, the takeover information management unit 122 of the SinkB (CL) 803 may measure a predetermined time after becoming the Secondary GO, and delete the takeover information when the predetermined time has elapsed. In this case, when the takeover information is received again from the sink A (GO) 802 before the predetermined time has elapsed, the stored takeover information can be updated and measurement of the predetermined time can be started again.

  FIG. 4 is a sequence diagram for explaining the operation of transferring the role of GO from Secondary GO to Secondary GO. In this description, as shown in FIG. 8 described as the prior art, a wireless communication system (P2P group (for example, Wi-Fi) including three units of Source A (CL) 801, Sink A (GO) 802, and Sink B (CL) 803). -A network conforming to Fi Direct))). Further, it is assumed that the connection of P2P communication has been completed in advance for the three units of SinkA (GO) 802, SourceA (CL) 802, and SinkB (GO) 803 using predetermined IP addresses 432 to 434 (step S430). explain.

  First, the sink A (GO) 802 determines (selects) the sink B (GO) 803 as a secondary GO (step S401). The sink A (GO) 802 transmits the takeover information to the sink B (CL) 803 determined as the secondary GO in step 401 (steps S202 and S402 in FIG. 2). In step S402, the sink B (CL) 803 receives the takeover information from the sink A (GO) 802, becomes a secondary GO, and monitors the disappearance of GO for the sink A (GO) 802 (step S411). .

  When the sink B (Secondary GO) 803 detects the disappearance of the GO of the Sink A (GO) 802 (Yes in step S302 in FIG. 3, step S412), the role is changed from CL to GO (step S413). Since the sink B (GO) 803 has changed the role from CL to GO in step S413, the DHCP Server control unit 115 activates the function as the DHCP server (step S414).

  When Source A (CL) 801 detects Sink B (GO) 803 that has newly become GO (Step S421), it transmits a reconnection request to Sink B (GO) 803 (Step S422). By such a procedure, even after the disappearance of the sink A 802, the sink B (GO) 803 and the source A (CL) 801 can maintain: continue the P2P group.

  Next, a process for the Source A (CL) 802 to extend the lease period (expiration date) for the IP address in use to the new GO Sink B (GO) 803 will be described. In step S423, for example, when the remaining lease time of DHCP is shortened, Source A (CL) 801 transmits a message (DHCP REQUEST) for requesting extension of the lease period to Sink A (old GO) 802. To do.

  However, since the DHCP Server (GO) was originally assigned to the Sink A (old GO) 802, the device having the IP address 432 assigned to the Sink A 802 (Sink A 802 that was responsible for GO) does not exist. Therefore, the lease period of the IP address cannot be extended. Accordingly, the Source A (CL) 801 searches for a new DHCP Server (GO) in the P2P group when the lease time of the IP address approaches. At this time, the DHCP Client control unit 116 of the Source A (CL) 801 transmits a message (DHCP DISCOVER) for discovering the DHCP Server to all devices in the network of the P2P group via the communication unit 105 (Step S1). S424).

  When the DHCP Server control unit 115 of the SinkB (GO) 803 receives the DHCP DISCOVER via the communication unit 105, the DHCP Server control unit 115 returns a message (DHCP OFFER) including an IP address that is an allocation candidate to the Source A (CL) 801. (Step S425). At this time, the sink B (GO) 803 can use the lease information included in the takeover information transmitted from the sink A 801 of the old GO as a candidate IP address to be assigned to the Source A (CL) 801. By such a procedure, the Source A (CL) 801 can continue to use the IP address 433 that was originally used.

  In step S426, the DHCP Client control unit 116 of the Source A (CL) 801 transmits a message (DHCP REQUEST) for requesting extension of the lease period to the IP address received in step S424 via the communication unit 105. To do. In step S427, the DHCP Server control unit 115 of the Sink B (GO) 803 transmits an acknowledgment message (DHCP ACK) to the DHCP REQUEST to the Source A (CL) 801 via the communication unit 105. The SourceA (CL) 801 can officially continue to use the IP address in use by the DHCP ACK received from the SinkB (GO) 803.

  In Sink A (GO) 802, when the battery runs out, if the processing from step S401 to step S427 described above is not performed, the P2P group is eliminated. When reconnecting within the P2P group again, processing such as GO negotiation and IP addressing by DHCP is required. However, by performing the processing from step S401 to step S427 shown in FIG. 4, processing such as GO negotiation and IP addressing by DHCP can be omitted, and the time required for CL reconnection can be shortened.

  As described above, in this embodiment, even if the wireless communication apparatus that has played the role of GO loses the role of GO for some reason, it is determined in advance as a secondary GO that is a candidate for GO, and the secondary GO is A new role of GO can be taken. Therefore, even when GO disappears in the P2P group, it is possible to construct a group with the remaining CL and maintain wireless connection. Further, processing such as GO negotiation and IP addressing by DHCP can be omitted, and the time required for CL reconnection can be shortened.

[Second Embodiment]
In the first embodiment, when the three wireless communication apparatuses (devices) 100 perform wireless communication, a method for transferring the role of GO that can continue wireless communication even when the GO suddenly disappears is shown. . In the present embodiment, a case of four wireless communication devices will be described. Note that, in the second embodiment, the same components as those of the wireless communication apparatus shown in FIG.

  FIG. 5 is a diagram illustrating a configuration before and after the disappearance of GO in the wireless communication system (P2P group) according to the second embodiment. In the second embodiment, as shown in FIG. 5, a case where display mirroring by Miracast is being executed in a P2P group constructed by four wireless communication apparatuses (devices) 100 will be described.

  As shown in FIG. 5A, a P2P group is configured by four units of Source A (CL) 501, Sink A (GO) 502, Sink B (CL) 503, and Sink C (CL) 504. Here, the video communication control unit 119 of the wireless communication apparatus 100 serving as the Source A 501 transmits compressed video and / or compressed audio information to the Sink A 502, Sink B 503, and Sink C 504 via the communication unit 105. In such a situation, as shown in FIG. 5B, even if the sink A (GO) 502 disappears for some reason, it is desirable that wireless communication can be continued between the remaining three units. However, this connection is disconnected because GO has disappeared. Here, it is possible to continue the P2P group even after the disappearance of GO by using the method of the first embodiment. However, when SinkB (CL) 503 is selected as a device to be the next GO, the following problem occurs.

  As a first problem, when the SinkB (CL) 503 is activated as a GO, it is necessary to determine the next GO again. This is because it is desirable that the source A (CL) 501 and the sink C (CL) 504 continue to operate even after the disappearance of the sink B (CL) 503 and the wireless communication is continued. Here, when SinkB (CL) 503 actually disappears, a GO replacement event occurs again.

  As a second problem, when SinkB (CL) 503 disappears before SinkA (GO) 502, a timing at which the next GO does not exist is generated. If SinkA (GO) 502 disappears at this timing, the P2P group disappears.

  That is, it is desirable to reduce the number of GO replacements as much as possible, and to consider the disappearance of Secondary GO. In order to solve such a problem, the wireless communication apparatus 100 according to the second embodiment determines the Secondary GO using the conditions illustrated in FIG.

FIG. 6 is a diagram illustrating conditions for the GO to determine the Secondary GO in the second embodiment. When selecting the secondary GO, the secondary GO selection unit 121 of the sink A (GO) 502 makes a determination based on the conditions of FIG. 6 based on the number of source devices and sink devices acquired from the other device management unit 123. Note that the number of source devices and sink devices in the P2P group does not include the sink A (GO) 502 itself.
Pattern 1: When there are a plurality of source devices and a single sink device, the sink device is selected as a secondary GO.
Pattern 2: When there is one source device and multiple sink devices, the source device is selected as a secondary GO.
Pattern 3: If there are no Source devices, the Secondary GO is not selected.
Pattern 4: If the number of sink devices is 0, the secondary GO is not selected.
Pattern 5: When there are a plurality of source devices and a plurality of sink devices, an arbitrary device is selected from the source devices or sink devices.

  That is, the GO measures the number of source devices and sink devices in the P2P group, and selects one device as a secondary GO when one is one and the other is a plurality. A method for measuring the number of source devices and sink devices in the P2P group will be described later.

  FIG. 7 is a flowchart for explaining processing until the GO determines a Secondary GO and transmits takeover information to the Secondary GO in the second embodiment.

  In step S701, the other device management unit 123 of the sink A (GO) 502 checks the role of the source / sink of all connected CLs. For this process, for example, the device information in the P2P group included in the WFD Device Info Descriptor field of the WFD Session Subscriber included in the WFD IE of the Sink A (GO) 502 itself is used. The WFD Device Info Descriptor field includes as many WFD Device Information fields as other devices indicating information on other devices in the group. The WFD Device Type bits in the WFD Device Information field indicate whether each device is a source or a sink. Therefore, the other device management unit 123 of the sink A (GO) 502 can measure the number of source devices and sink devices in the P2P group by referring to the WFD device type bits for each device. However, the other apparatus management unit 123 can also measure the number of source devices and sink devices by a method other than the above.

  In step S <b> 702, the secondary GO selection unit 121 of the sink A (GO) 502 determines which device (wireless communication apparatus) is the secondary GO based on the conditions shown in FIG. 6 based on the number of source devices and sink devices. To do. When there are a plurality of source devices and a plurality of sink devices (step S703), the secondary GO selection unit 121 determines an arbitrary device from the source devices or sink devices as the secondary GO. When there is one source device and a plurality of sink devices (step S704), the secondary GO selection unit 121 determines that the source device is a secondary GO. When there are a plurality of source devices and one sink device (step S705), the secondary GO selection unit 121 determines the sink device to be a secondary GO. If there are no source devices or no sink devices (step S706), the secondary GO selection unit 121 does not determine the secondary GO, and this flow ends.

  Subsequently, the GO control unit 112 of the Sink A (GO) 502 transmits takeover information via the communication unit 105 to the device determined as the Secondary GO. The processing in step S707 is the same as that in step S202 in FIG. 2 described in the first embodiment, and thus the description thereof is omitted.

  As described above, in the present embodiment, when the GO disappears and the number of remaining wireless communication devices (CL) in the P2P group becomes 3 or more, the effect of considering the role of the source / sink of the remaining CL is considered. In addition, Secondary GO can be selected.

  Thus, according to the embodiment described above, even when the GO disappears in the P2P group, the group can be constructed with the remaining CL and the wireless connection can be maintained. Therefore, when a group is reconstructed with the remaining CL, processing such as GO negotiation and IP addressing by DHCP can be omitted, and the time required for CL reconnection is shortened. Furthermore, an appropriate device can be selected as GO in consideration of the role of the device in Miracast.

[Other Embodiments]
In the above-described embodiment, a network conforming to Wi-Fi Direct is assumed. However, the present invention is not limited to this, and the above-described embodiment can be applied to other types of networks. Further, instead of the source device and the sink device in the above embodiment, a device that provides a predetermined service and a device that is provided may be used.

  The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 100 Wireless communication apparatus, 111 Wireless communication control part, 112 GO control part, 113 CL control part, 114 P2P Role switching control part, 115 DHCP Server control part, 116 DHCP Client control part, 117 Display device control part, 118 Codec control part 119 Video communication control unit, 120 GO loss detection unit, 121 Secondary GO selection unit, 122 Takeover information management unit, 123 Other device management unit

Claims (18)

In a network composed of a plurality of wireless communication devices, a wireless communication device that functions as an access point,
Of the other wireless communication devices in the network, the wireless communication device functioning as the access point has disappeared from the network based on the number of wireless communication devices on the providing side and the receiving side of the predetermined service. Selecting means for selecting a wireless communication device to function as the access point in case
Transmitting means for transmitting predetermined information for taking over the network to the selected wireless communication device;
A wireless communication apparatus comprising:   The wireless communication apparatus according to claim 1, wherein the predetermined service includes content transmission / reception. In a network composed of a plurality of wireless communication devices, a wireless communication device that functions as an access point,
A wireless communication device that should function as the access point when a communication device that functions as the access point disappears from the network based on information about the other wireless communication device among other wireless communication devices in the network A selection means for selecting
Transmitting means for transmitting predetermined information for taking over the network to the selected wireless communication device;
A wireless communication apparatus comprising:   The selection means has a function to become the access point using the battery information, the information indicating the likelihood of becoming the access point, the radio wave intensity, and the predetermined information in each of the other wireless communication devices. The wireless communication device according to claim 3, wherein a wireless communication device to function as the access point is selected based on at least one of the above.   When the number of wireless communication devices in the network changes after selecting the wireless communication device that should function as the access point by the selection unit, the selection unit again selects from other wireless communication devices in the network. The wireless communication apparatus according to claim 1, wherein a wireless communication apparatus to function as the access point is selected.   The selection unit selects the first other wireless communication device as the wireless communication device to function as the access point, and when the second other wireless communication device is selected by the second selection, the transmission means The means transmits a request for deleting the transmitted predetermined information to the first other wireless communication apparatus, and transmits the predetermined information to the second other wireless communication apparatus. The wireless communication apparatus according to claim 5, wherein the wireless communication apparatus transmits the wireless communication apparatus.   The wireless communication apparatus according to claim 1, wherein the transmission unit transmits the predetermined information a plurality of times to the selected wireless communication apparatus. A management means for managing the predetermined information;
8. The transmission unit according to claim 1, wherein when the predetermined information is changed by the management unit, the transmission unit transmits the changed information to the selected wireless communication apparatus. The wireless communication device according to claim 1. In a network composed of a plurality of wireless communication devices, a wireless communication device that functions as an access point,
A selecting means for selecting a wireless communication device to function as the access point when the communication device functioning as the access point disappears from the network from other wireless communication devices in the network;
Transmitting means for transmitting predetermined information for taking over the network to the selected wireless communication device;
A wireless communication apparatus comprising:   The wireless communication device according to any one of claims 1 to 9, wherein the wireless communication device is a wireless communication device that functions as a Group Owner in a network that conforms to Wi-Fi Direct. A wireless communication device in a network composed of a plurality of wireless communication devices,
Receiving means for receiving predetermined information for taking over the network from a wireless communication device functioning as an access point in the network;
Detecting means for detecting whether or not the wireless communication device functioning as the access point has disappeared from the network;
Network control means for taking over the network using the predetermined information when the detection means detects that the wireless communication device functioning as the access point has disappeared from the network;
A wireless communication apparatus comprising:   12. The wireless communication apparatus according to claim 11, further comprising a management unit that deletes the predetermined information when a predetermined time has elapsed since the reception unit received the predetermined information.   The wireless communication device according to claim 11 or 12, wherein the wireless communication device is a wireless communication device functioning as a Client in a network conforming to Wi-Fi Direct.   The wireless communication according to any one of claims 1 to 13, wherein the predetermined information includes at least one of information necessary for encryption and address information necessary for connection to the network. apparatus. A method of controlling a wireless communication device that functions as an access point in a network composed of a plurality of wireless communication devices,
A communication device functioning as an access point disappears from the network based on the number of wireless communication devices on the providing side and the receiving side among other wireless communication devices in the network Selecting a wireless communication device to function as the access point;
A transmitting step of transmitting predetermined information for taking over the network to the selected wireless communication device;
A control method for a wireless communication apparatus, comprising: A method of controlling a wireless communication device that functions as an access point in a network composed of a plurality of wireless communication devices,
A wireless communication device that should function as the access point when a communication device that functions as the access point disappears from the network based on information about the other wireless communication device among other wireless communication devices in the network A selection process for selecting
A transmitting step of transmitting predetermined information for taking over the network to the selected wireless communication device;
A control method for a wireless communication apparatus, comprising: A method for controlling a wireless communication device in a network composed of a plurality of wireless communication devices,
Receiving a predetermined information for taking over the network from a wireless communication device functioning as an access point in the network;
A detection step of detecting whether or not the wireless communication device functioning as the access point has disappeared from the network;
A network control step of taking over the network using the predetermined information when it is detected that the wireless communication device functioning as the access point has disappeared from the network in the detection step;
A control method for a wireless communication apparatus, comprising:   The program for functioning a computer as a radio | wireless communication apparatus of any one of Claim 1 to 14.

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