JP6141398B2 - COMMUNICATION DEVICE, COMMUNICATION METHOD, PROGRAM - Google Patents

Description

  The present invention relates to a communication device, a communication method, and a program that can participate in a plurality of networks.

  In wireless communication represented by a wireless LAN compliant with the IEEE 802.11 standard series, an infrastructure mode in which an access point (base station) controls the network and an ad hoc mode in which a terminal device autonomously configures the network are defined. .

In addition, a method for communicating with another terminal apparatus in the ad hoc mode at the same time as connecting to the base station in the infrastructure mode has been proposed. (For example, refer to Patent Document 1.)
A function capable of configuring a plurality of networks with one terminal device is called a multi-BSS (Basic Service Set) function. The multi-BSS function may be executed on a single wireless LAN interface for reasons such as cost reduction. When connecting to a base station in the infrastructure mode by the multi-BSS function and simultaneously communicating with another terminal apparatus in the ad hoc mode, communication in each mode is performed on the same wireless LAN channel (frequency channel). For this reason, when the wireless LAN channel on the infrastructure mode (infrastructure mode) side is changed for reasons such as roaming, it is necessary to change to the same wireless LAN channel also in communication on the ad hoc mode side.

JP 2005-64552 A

  Consider a case in which a terminal device that communicates with another terminal device in the ad hoc mode changes the communication channel on the infrastructure mode side by roaming while connecting to the base station in the infrastructure mode. In this case, if the terminal device also changes the communication channel on the ad hoc mode side, the terminal device has left the ad hoc network.

  Therefore, it becomes impossible to communicate with other terminal devices that existed in the same ad hoc network. Here, when the other terminal device detects the removal of the roamed terminal device, it can detect the roamed terminal device on another channel by scanning the wireless network. However, when the roaming terminal device has already ended the communication in the ad hoc mode, the other terminal device cannot detect the roaming terminal device, but results in a useless scan.

  As described above, there is a problem that other terminal devices cannot maintain communication with the terminal device that has left the ad hoc network, and are unusable.

A communication apparatus according to an aspect of the present invention is connected to a base station, communicates as a slave station via the base station, and communicates directly with a communication partner apparatus without passing through the base station. A radio interface that performs communication in parallel when a common frequency channel is used, and the first communication and the second communication that are performed in parallel using a first frequency channel When a beacon cannot be detected in the first communication, a scanning unit that performs scanning and a network that can be connected to perform the first communication by scanning by the scanning unit are detected using the second frequency channel. If, change the channel to be used for the first communication to a second frequency channel from the first frequency channel, or one, the second communication using the second frequency channel And control means for controlling the radio interface to listen to the communication partner device to continue using the second frequency channel, when performing control by said control means, in said second communication, the second A transmission unit that transmits information indicating a frequency channel to the communication partner device using the wireless interface, and the communication partner device uses the second frequency channel for communication after control by the control unit. When the radio interface is switched, the radio interface performs the first communication and the second communication in parallel using the second frequency channel.

  According to the present invention, when communicating via a base station using a first frequency channel and communicating via the base station using the first frequency channel, When the frequency channel used for the communication is changed to the second frequency channel, the second frequency channel can be controlled to communicate without going through the base station.

Block configuration diagram of an apparatus according to an embodiment of the present invention Software function diagram of an apparatus according to an embodiment of the present invention Network configuration diagram according to an embodiment of the present invention FIG. 4 is a flowchart of the operation of the communication apparatus according to the embodiment of the present invention when switching the network. First operation sequence diagram of terminal 301, terminal 302, access point 303, and access point 304 in the network configuration according to the embodiment of the present invention Second operation sequence diagram of terminal 301, terminal 302, access point 303, and access point 304 in the network configuration according to the embodiment of the present invention Third operation sequence diagram of terminal 301, terminal 302, access point 303, and access point 304 in the network configuration according to the embodiment of the present invention

[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 is a block diagram illustrating an example of the configuration of each device described below. 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, and is a computer such as a CPU or MPU. The control unit 102 also performs execution control of communication parameter automatic setting processing performed with other devices. Reference numeral 103 denotes a storage unit that stores a computer program for control 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. Note that the storage unit 103 can be a memory such as a ROM or a RAM, or 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 DVD, or the like.

  Reference numeral 104 denotes a wireless unit for performing wireless communication. 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. Reference numeral 106 denotes an input unit for the user to make various inputs. Reference numeral 107 denotes an antenna control unit, and reference numeral 108 denotes an antenna.

  FIG. 2 is a configuration example of software function blocks executed by a communication apparatus that supports the multi-BSS function in processing operations described later. Reference numeral 201 denotes the entire apparatus. A packet transmission unit 202 transmits packets related to various types of communication. Transmission of each signal to be described later is performed by the packet transmission unit 202. A packet receiving unit 203 receives packets related to various types of communication. Reception of each signal to be described later is performed by the packet receiving unit 203. A BSS-STA function control unit 204 controls the operation as a terminal station (STA) of an infrastructure mode network (BSS) that connects to a base station (access point) and performs wireless communication. Processing operations as an infrastructure mode terminal station in the wireless LAN network, such as transmission / reception of a search signal of the base station and connection processing with the base station, are performed by the BSS-STA control unit 204. 205 is an IBSS-STA function control unit that controls the operation as a terminal station (STA) in an ad hoc mode (IBSS: Independent Basic Service Set) in which wireless communication is performed without connecting to a base station. The processing operation as an ad hoc mode terminal station described later is performed by the IBSS-STA function control unit 205. Reference numeral 206 denotes a connection network confirmation control unit that confirms and controls a connection state with the network. A process at the time of network switching, which will be described later, is performed by the connected network confirmation control unit 206.

  FIG. 3 is a diagram illustrating a network group including the communication device 301, the communication device 302, the access point 303, and the access point 304. The communication devices 301 and 302 have the configuration shown in FIGS. 1 and 2 described above. The communication device 301 is connected to the BSS network 305 managed by the access point 303. In addition, the communication device 301 and the communication device 302 participate in the IBSS network 307. Further, the access point 304 manages the BSS network 306. The BSS network is a Basic Service Set network and is a basic network in an infrastructure mode. The IBSS network is an Independent Basic Service Set network and is a basic network in an ad hoc mode.

  In this embodiment, it is assumed that the network 305 and the network 306 have the same ESSID (Extended Service Set Identification) and are configured as networks that can roam.

  FIG. 4 shows a switching process operation performed by the connection network confirmation control unit 206 when a communication apparatus that is implementing the multi-BSS function switches a connection from a connected BSS network to another BSS network (when roaming). FIG. FIG. 4 is performed by the control unit 102 reading and executing the computer program stored in the storage unit 103.

  Note that the processing in FIG. 4 is performed, for example, when switching networks by wireless LAN roaming. Further, not only in the case of wireless LAN roaming, but may operate when another connectable network is discovered after leaving the BSS connected network.

  When the communication device 301 is wirelessly connected to the access point 303, the wireless connection environment with the access point 303 is improved, and the wireless connection environment with the access point 304 is improved. Start the roaming process.

  When the connection network confirmation control unit 206 of the communication device 301 detects the start of the roaming process, the connection network confirmation control unit 206 of the communication device 301 determines whether it is connected to the infrastructure mode network and the ad hoc mode network by the multi-BSS function. To do. When connected to the infrastructure mode network and the ad hoc mode network by the multi-BSS function, the processing of FIG. 4 is started. When connected to the infrastructure mode network only, roaming to the BSS network 306 of the access point 304 is performed.

  In the process of FIG. 4, the connection network confirmation control unit 206 of the communication device 301 confirms whether or not ad hoc mode communication is possible on the wireless LAN channel (frequency channel) of the switched network (S401). Here, it is confirmed whether the wireless LAN channel used by the access point 304 of the BSS network 306, which is the wireless LAN channel of the network after switching, is a wireless LAN channel for which communication in the ad hoc mode is prohibited.

  When the switched network is a wireless LAN channel that can communicate in the ad hoc mode, the BSS-STA function control unit 204 notifies the other terminal that is communicating in the ad hoc mode that it will change the wireless LAN channel. (S402). Here, the information indicating that the wireless LAN channel is changed and the information indicating the switching destination wireless LAN channel are broadcast to the ad hoc network before switching. The notification in step S402 makes it possible for another communication device to quickly detect a change in the wireless LAN channel, and the other communication device quickly performs an appropriate process such as changing the wireless LAN channel following the change. It becomes possible.

  After the notification in S402, the BSS-STA function control unit 204 changes the wireless LAN channel in the ad hoc mode (S403), and the IBSS-STA function control unit 205 switches the network in the infrastructure mode (S404). To communicate with. Switching the network in the infrastructure mode is performed by switching to the switching destination network (here, the wireless LAN channel of the BSS network 306), but connection processing to the access point 304 is also performed by the IBSS-STA function control unit 205.

  If the result of determination in step S401 is that the switched network is operating on a wireless LAN channel that cannot be communicated in ad hoc mode, the connected network confirmation control unit 206 confirms the setting information so that it can It is confirmed which mode of the ad hoc mode should be preferentially operated (S405). The setting information referred to in step S405 is stored in the storage unit 103. This setting information can be changed by the operation of the input unit 106 by the user.

  In step S405, when the communication device is set to give priority to the infrastructure mode, the BSS-STA function control unit 204 ends communication in the ad hoc mode toward another terminal communicating in the ad hoc mode. (S406).

  After this notification, the BSS-STA function control unit 204 terminates the ad hoc mode communication (S407), and the IBSS-STA function control unit 205 switches the infrastructure mode network (S404), and performs communication in the switching destination network. .

  In step S405, if the communication device is set to prioritize the ad hoc mode, the IBSS-STA function control unit 205 ends the communication in the infrastructure mode (S408) and ends the process. Note that in the case of setting to prioritize the ad hoc mode in step S405, the communication device 301 does not roam from the BSS network 305 to the BSS network 306, so that the BSS network 305 can be wirelessly connected to the access point 303 as much as possible. The wireless connection with the access point 303 is continued.

  The notification process in step S402 is performed by transmitting a broadcast message on the ad hoc network. However, the notification process may be performed by exchanging messages individually between communication apparatuses.

  In addition, the setting information referred to in step S405 may set the priority mode fixedly, for example, always prioritize the infrastructure mode, or the application being executed such as giving priority to the operation mode during real-time communication. You may set dynamically according to.

  When the network after switching uses the same wireless LAN channel as the network before switching, the connected network confirmation control unit 206 may switch the network without performing the processing described in FIG.

  FIG. 5 shows a connection when the wireless LAN roaming is performed due to the movement of the communication device 301 or the like when the communication device 301 is connected to the access point 303 and the connection is switched to the BSS network 306 of the access point 304. It is a processing sequence. Here, the communication apparatus 301 implements the multi-BSS function, and configures the IBSS network 307 with the communication apparatus 302 to perform ad hoc mode communication. Note that the BSS network 305 and the IBSS network 307 operate on the wireless LAN channel a (frequency channel a). Further, it is assumed that the BSS network 306 operates on a wireless LAN channel b (frequency channel b) capable of ad hoc mode communication.

  The communication device 301 detects the loss of the beacon from the access point 303 and starts the wireless LAN roaming process (F501).

  For example, the communication device 301 searches for surrounding APs by executing a wireless LAN scan (F502), and receives a response signal from the access point 304, thereby selecting the network 306 as a roaming destination (F503).

  After selecting the network 306, the communication device 301 performs the network switching process described in FIG. 4 and can perform the ad hoc mode communication on the channel b. To change the channel and to switch to channel b (F504).

  After this notification, the communication device 301 changes the wireless LAN channel in the ad hoc mode to channel b (F505), and similarly, the communication device 302 that has received the notification changes the wireless LAN channel in the ad hoc mode to channel b (F506). .

  After changing the wireless LAN channel in the ad hoc mode, the communication apparatus 301 connects to the network 306 and completes the wireless LAN roaming (F507).

  As described above, when the switching process described in FIG. 4 is performed, when the wireless LAN channel in the infrastructure mode is changed to a channel in which communication in the ad hoc mode can be performed, the wireless LAN channel in the ad hoc mode is quickly switched. be able to.

  FIG. 6 is a connection processing sequence when the communication apparatus 301 switches the connection to the BSS network 306 that operates on the wireless LAN channel c where communication in the ad hoc mode is impossible. Here, it is assumed that the communication device 301 is set to give priority to infrastructure mode communication.

  The communication device 301 detects the loss of the beacon from the access point 303 and starts the wireless LAN roaming process (F601).

  For example, the communication device 301 searches for surrounding APs by executing a wireless LAN scan (F602), and receives a response signal from the access point 304, thereby selecting the network 306 as a roaming destination (F603).

  After the selection of the network, the communication device 301 performs the network switching process described in FIG. 4 and cannot perform the ad hoc mode communication on the channel c. Therefore, the communication device 301 communicates with the communication device 302 in the ad hoc mode. Is notified (F604).

  After this notification, the communication device 301 ends the ad hoc mode communication (F605), and similarly, the communication device 302 that has received the notification also ends the ad hoc mode communication (F606).

  After completing the ad hoc mode communication, the communication device 301 connects to the network 306 and completes the wireless LAN roaming (F607).

  FIG. 7 shows a sequence when the network of the access point 304 to be roamed operates on the wireless LAN channel c incapable of ad hoc mode communication, and the communication apparatus 301 is set to give priority to ad hoc mode communication. It is.

  The communication device 301 detects the loss of the beacon from the access point 303 and starts the wireless LAN roaming process (F701).

  The communication apparatus 301 searches for surrounding APs by executing, for example, a wireless LAN scan (F702), and receives a response signal from the access point 304, thereby selecting the network 306 as a roaming destination (F703).

  After selecting the network, the communication apparatus 301 performs the network switching process described in FIG. 4 and cannot perform the ad hoc mode communication on the channel c. Communication is continued (F704).

  As described above, when the wireless LAN channel is changed to a channel incapable of ad hoc mode communication by performing the switching process described in FIG. 4, the priority communication mode is continuously executed, and It is possible to quickly end the non-priority communication mode.

  As described above, according to the present embodiment, when a change process of a base station is detected when participating in a network that communicates with a base station without communicating with the base station, the change destination Processing according to the frequency channel of the base station can be performed. That is, when the frequency channel of the base station to be changed can be used even in communication that is not connected to the base station, the change of the frequency channel can be notified and the frequency channel of other communication devices can be changed quickly. In addition, when the frequency channel of the base station to be changed cannot be used in communication not connected to the base station, either communication connected to the base station or communication not connected to the base station can be preferentially performed. In addition, the user can set which is prioritized, and usability can be improved.

  The preferred embodiment of the present invention has been described above. However, this is merely an example for explaining the present invention, and the scope of the present invention is not limited to this example. The embodiment can be variously modified without departing from the gist of the present invention. Also, the above description has been made with reference to an IEEE 802.11-compliant wireless LAN as an example. However, the present invention may be implemented in other wireless media such as wireless USB, MBOA, Bluetooth (registered trademark), UWB, and ZigBee.

  Here, MBOA is an abbreviation for Multi Band OFDM Alliance. UWB includes wireless USB, wireless 1394, WINET, and the like.

DESCRIPTION OF SYMBOLS 201 Communication apparatus 202 Packet receiving part 203 Packet transmission part 204 BSS-STA function control part 205 IBSS-STA function control part 206 Connection network confirmation control part

Claims (12)

A common frequency channel is used for the first communication that connects to a base station and communicates as a slave station via the base station, and the second communication that communicates directly with a communication partner device without going through the base station. A wireless interface that runs in parallel,
Scanning means for performing a scan when a beacon cannot be detected in the first communication when the first communication and the second communication are performed in parallel using the first frequency channel;
When a connectable network for performing the first communication is detected using the second frequency channel by scanning by the scanning means, the channel used for the first communication is changed from the first frequency channel to the second frequency channel. change the frequency channel, or one, control the radio interface to listen to the communication partner apparatus said second communication in order to continue using the second frequency channel by using the second frequency channel Control means to
When performing the control by the control means, in the second communication, having transmission means for transmitting information indicating the second frequency channel to the communication counterpart device using the wireless interface ,
When the communication partner apparatus switches the channel used for communication to the second frequency channel after the control by the control means, the wireless interface performs the second communication between the first communication and the second communication. A communication apparatus that performs in parallel using a frequency channel. The transmission unit, in the second communication, characterized that you send to the communication partner apparatus by using the radio interface by using the second of the first frequency channel information indicating a frequency channel The communication apparatus according to claim 1.   A second base station that is different from the first base station that communicates using the first frequency channel and communicates using the second frequency channel is constructed by scanning by the scanning means. The wireless interface is controlled to change a channel used for the first communication from the first frequency channel to the second frequency channel when a network to be detected is detected. The communication device described. The radio interface, said as a first communication, the communication device according to any one of claims 1 to 3, characterized in that the communication in the infrastructure mode. The wireless interface, as the second communication, the communication device according to any one of claims 1 to 4, characterized in that communicate over the ad-hoc mode. The wireless interface, a communication device according to any one of claims 1 to 5, characterized in that wireless communication complying with the IEEE802.11 series. The wireless interface, a communication device according to any one of claims 1 to 6, characterized in that by using the first communication and the second communication and a common antenna. The radio interface, multi by BSS function, the communication device according to any one of claims 1 to 7, characterized in that in parallel with the second communication with the first communication. It said scanning means transmits the search signal, the communication device according to any one of claims 1 to 8, characterized in that performing a scan by receiving a response signal to the search signal. The scanning means performs a scan to detect a network having a predetermined network identifier connected using the first frequency channel.
When the communication device detects a network having the predetermined network identifier using the second frequency channel by scanning by the scanning unit, the communication device identifies the frequency channel used for communication by the wireless interface as the second frequency channel. communication device according to any one of claims 1 to 9, characterized in that. A common frequency channel is used for the first communication that connects to a base station and communicates as a slave station via the base station, and the second communication that communicates directly with a communication partner device without going through the base station. A communication method of a communication device having a wireless interface to be performed in parallel,
A scanning step of performing a scan when a beacon cannot be detected in the first communication when the first communication and the second communication are performed in parallel using the first frequency channel;
When a connectable network for performing the first communication is detected using the second frequency channel by scanning in the scanning step, the channel used for the first communication is changed from the first frequency channel to the second frequency channel. change the frequency channel, or one, control the radio interface to listen to the communication partner apparatus said second communication in order to continue using the second frequency channel by using the second frequency channel A control process,
When performing control in the control step, in the second communication, a transmission step of transmitting information indicating the second frequency channel to the communication counterpart device using the wireless interface;
When the communication partner apparatus switches the channel used for communication to the second frequency channel after the control in the control step, the wireless interface transmits the first communication and the second communication to the second frequency channel. Performing in parallel using frequency channels;
A communication method characterized by comprising: Program for operating a computer as a communication device according to any one of claims 1 to 1 0.

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