JP2007019601A - Radio communication apparatus, transmission control method, reception control method and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the collision of an IP address acquired by an Auto IP against the IP address of the other terminal even if a communication distance changes due to the movement of the terminals during data communication. <P>SOLUTION: The transmission power of radio communication is increased compared to the case of usual data transmission in an addressing sequence using the Auto IP. Also, the transmission power of radio communication is increased compared to the case of usual data transmission in retransmitting a duplicate inspection packet after a duplicate notification packet is received. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication device, a transmission control method, a reception control method, and a storage medium, and in particular, there is no server or administrator that performs centralized management of terminal identifiers on a network such as an IP address, and terminals are distributed by terminal distributed control The present invention relates to a wireless communication system for performing identifier duplication resolution.

  In recent years, in wire communication, a standard that can be used immediately by connecting various devices with a cable (cable), and a product that implements the standard have appeared. For example, PictBridge (CIPA DC-001) that can connect a digital camera and a printer with a USB (Universal Serial Bus) cable for printing is standardized.

  With digital cameras and printers that use this standard, the printer is ready for printing when it is connected via USB, and then the user interface of the digital camera (the digital camera has a liquid crystal display and a monitor for confirming captured images) It is possible to perform a printing operation simply by designating an image to be printed in (provided with various keys).

  On the other hand, there is a growing demand for wireless transmission of information that has been carried out by wire by a wireless communication method based on the international standard IEEE 802.11, and wireless communication is also used for communication between peripheral devices such as digital cameras, storages, and printers. It is starting to be used. Wireless communication eliminates the need for cable laying, increases the degree of freedom of the setting location of each device, and improves portability.

  In such a wireless communication device, a predetermined communication mode, an ID (ESS-ID), a channel for specifying a frequency band, and the like are set in advance, and other settings in the communication network are set in the communication mode and the like. The communication within the communication network is established by combining the setting of the apparatus, that is, the client side (see, for example, Patent Document 1).

  Note that the communication mode includes an “ad-hoc mode (Peer to Peer)” in which a communication network is formed only by a device equipped with a wireless LAN card, and an existing access point via an access point of a repeater in the communication network. There is an “infrastructure mode” for connecting to a network.

  2. Description of the Related Art Conventionally, a method called Auto IP has been proposed as a method for assigning each terminal a unique IP address in an ad hoc network where there is no network administrator or management server.

  In Auto IP, a device connected to a network determines an arbitrary temporary address from 169.254.0.1 to 169.254.255.255, which is a reserved range, and broadcasts this temporary address to the network. The other network terminal that has received the temporary address returns a message only when the temporary address is equal to its own address. When this message is returned, another temporary address is determined and broadcast is performed again. By repeating this process until there are no messages returned, an address that is not currently used in the network is acquired, and this address is assigned as its own address.

  Assume that a wireless ad hoc network as shown in FIG. 3 exists.

  Terminal A300, terminal B301, and terminal C302 in FIG. 3 each form a wireless ad hoc network in the network within the communicable range 304 of terminal A. On the other hand, it is assumed that a terminal D303 having the same IP address as that of the terminal A301 exists outside the network.

FIG. 4 is a diagram illustrating that a terminal D403 having the same IP address as that of the terminal A400 has joined the wireless ad hoc network similar to that in FIG. 3 due to movement of the terminal. As a result, the terminal A and the terminal D having the same IP address exist in the same network, and a collision of IP addresses occurs.
Japanese Patent Laid-Open No. 2004-241911

  As described above, in a situation where a plurality of terminals in a network outside the communicable range communicate with each other using the same IP address, they can communicate with each other by changing the communication distance due to the movement of the terminal. In some cases, an IP address may collide with another device during communication.

  The present invention has been made paying attention to the above points. The IP address acquired by Auto IP collides with other terminals even if the communication distance changes due to movement of the terminal during data communication. An object of the present invention is to provide a wireless communication device, a transmission control method, a reception control method, and a storage medium that prevent the above.

  In order to solve the above problems, a wireless communication apparatus according to the present invention has the following configuration.

That is, a wireless communication device,
A control unit that controls the operation of each unit of the wireless communication device;
In the control unit, wireless transmission means for transmitting a data packet or control packet generated by data or a control command;
Wireless receiving means for receiving a data packet or a control packet transmitted by a communication partner;
Transmission control means for controlling the signal reach of packets transmitted from the wireless transmission means,
The transmission control means controls the signal arrival range at the time of test packet transmission for determining its own address to be wider than at the time of data packet transmission,
The wireless transmission means transmits the inspection packet within the signal reachable range.

In the above wireless communication device,
A reception control means for controlling a signal reception range of a packet received by the wireless reception means;
The reception control means controls the signal reception range at the time of receiving a notification packet to notify that its own address is duplicated to be wider than at the time of receiving the data packet,
The wireless reception unit may receive the notification packet within the signal reception range.

  The present invention can also be configured as a computer program for controlling a wireless communication device.

That is, a transmission control method in a radio communication apparatus, including a radio transmission unit that transmits an inspection packet for determining its own address to a communication partner, and a transmission control unit that controls a signal reach when transmitting the inspection packet Because
Generating the inspection packet and sending it to the wireless transmission means and the transmission control means;
In the transmission control means, performing a control to make a signal reach range at the time of transmission of the inspection packet wider than at the time of data packet transmission;
And the step of transmitting the inspection packet within the signal reach by the wireless transmission means.

In the above wireless communication device control method, after transmitting an inspection packet for determining its own address to the communication partner,
Receiving control in a wireless communication apparatus, including a wireless receiving unit that receives a notification packet for notifying that the address of the communication partner is duplicated, and a reception control unit that controls a signal reception range when the notification packet is received A method,
Notifying the reception control means of inspection packet transmission to the communication partner;
In the reception control means, performing a control so that a signal reception range at the time of receiving the notification packet is wider than that at the time of receiving the data packet;
A step of waiting for reception of the notification packet within the signal reception range by the wireless reception means may be provided.

  According to the present invention, it is possible to prevent an IP address acquired by Auto IP from colliding with another terminal even if the communication distance changes due to movement of the terminal during data communication.

  Further, during data communication, power consumption can be reduced to suppress transmission output.

  Embodiments of a wireless communication apparatus according to the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 2 shows the main part when the present invention is applied to a system comprising a digital camera 201 and a printer 231 connected to the digital camera via wireless communication means.

  The digital camera 201 and the printer 231 according to the present invention include an interface for performing wireless communication. In the present invention, the IEEE802.11b system is used as the wireless interface.

  In the IEEE802.11b system, there is a communication called “ad hoc mode” in which a network is formed only by a device equipped with a wireless LAN adapter, and “infrastructure mode” in which an existing network is connected via an access point of a repeater in the communication network. There is a mode.

  Auto IP is a function for determining a unique IP address in the ad hoc mode.

  Hereinafter, each configuration of FIG. 2 will be described in detail.

  First, the digital camera 201 receives a photographic lens, a CCD that receives subject light incident through the photographic lens, photoelectrically converts it to generate an image signal, an analog / digital (A / D) conversion circuit, etc. at the subsequent stage. An imaging unit 204 is provided. The imaging unit 204 outputs a digital image signal under the control of the CPU 217 and performs signal processing by the signal processing unit 202, and then temporarily stores the digital image signal in the RAM 203. Thereafter, the created digital image signal is finally stored as an image file in the compact flash (registered trademark) 205.

  The CPU 217 further includes a ROM 208, a SW control unit 209 for controlling inputs from various operation members 210, a VRAM 206 for holding display data for digital image signals and display data for various user interfaces, a wireless communication interface 211, a USB A communication interface 216 compliant with the standard and a flash ROM 215 for holding various parameters and various information are connected. The contents of the display data held in the VRAM 206 are displayed on the LCD monitor 207.

  The various operation members 210 instruct a power supply SW (not shown) for controlling ON / OFF of the power supply, a release SW (not shown) for instructing photographing, and the LCD monitor 207 to display a digital image signal. SW (not shown) for displaying a menu on the LCD monitor 207 (not shown), SW used for sending and returning image frames, and changing the menu selection state (not shown) And a touch panel (not shown) that gives instructions directly on the liquid crystal.

  As an operation mode of the digital camera, at least a power-off mode, a recording mode, a reproduction mode, and a print mode are provided. These modes can be shifted by an instruction from the operation member 210.

  In the digital camera of this embodiment, in order to join a wireless ad hoc network as shown in FIG. 3, address determination is attempted using Auto IP.

  In the flash ROM 215 of the present embodiment, a wireless setting value storage area 220 for storing the determined IP address and the like is secured. This area also holds information such as a communication mode such as ad hoc and a communication channel to be used.

  In the ROM 208 of this embodiment, a packet transmission unit 219 for processing transmission packets and a packet reception unit 218 for processing reception packets are held as software programs.

  The wireless communication interface 211 includes a controller 212, an RF module 213, and an antenna 214.

  The controller 212 is a controller that performs baseband control (wireless interface control) or the like for performing wireless communication in accordance with the IEEE 802.11b protocol, and transmits and receives data to and from the CPU 217. It also controls radio communication reception sensitivity and transmission output.

  The RF module 213 is a module that performs A / D conversion, D / A conversion, and the like of signals in order to wirelessly communicate data, and is connected to the antenna 214.

  The antenna 214 radiates a signal converted into an analog signal by the RF module 213 as a radio wave. Also, an analog signal is received and sent to the RF module 213.

  On the other hand, the printer 231 includes a wireless communication interface 241 that is the same as the wireless communication interface of the digital camera, and includes a controller 242, an RF module 243, and an antenna 244, as with the digital camera 201.

  The wireless communication interface 241 is connected to the CPU 245 of the printer. The CPU is further connected to an image memory 232, a ROM 236 for storing printer programs, a paper transport unit 237, a communication interface 240 compliant with the USB standard, and a flash ROM 238 for storing various parameters and various information. ing. The CPU is further connected to the buffer memory 233 and further to the printer head 235 via the driver 234.

  Image data to be printed transmitted from the digital camera 201 is temporarily stored in the image memory 232 via the wireless communication interface 241. When the printer receives a print data print instruction transmitted from the digital camera 201, the CPU 245 drives the paper transport unit 237 to first feed the paper to be printed, and sets the paper at the print start head position. At the same time, the temporarily stored image data is expanded to create print data for one line, transferred to the buffer memory 233, and controlled by the printer head 235 via the driver 234 to start printing. . The print head 235 can print the data for one line of the printing paper at the same time, and the paper transport unit 237 transports the paper for one line every time one line is printed.

  In this way, the CPU 245 is driven while synchronizing the transfer of the paper transport unit 237 and the print data to the print head 235.

  After performing a desired image printing operation in this way, the CPU 245 drives the paper transport unit 237 to discharge the paper.

  A power SW 239 for instructing power ON / OFF is connected to the CPU 245. When the user turns on the power SW, the printer 231 is turned on.

  In the printer of this embodiment, as with the digital camera 201, in order to join a wireless ad hoc network as shown in FIG. 3, address determination is attempted using Auto IP.

  In the flash ROM 238 of this embodiment, a wireless setting value storage area for storing the determined IP address and the like is secured. This area also holds information such as a communication mode such as ad hoc and a communication channel to be used.

  In the ROM 236 of this embodiment, packet transmission means 247 for processing transmission packets and packet reception means 246 for processing reception packets are held as software programs.

  An IP addressing sequence in the digital camera 201 in this embodiment will be described.

  First, FIG. 5 shows elements of a duplicate check packet used for IP address duplication check used in the Auto IP procedure. A terminal that transmits a duplicate check packet has an identifier indicating broadcast to all terminals in the destination physical address 500, a physical address of the terminal itself in the source physical address 501, and a duplicate check packet in the packet type identifier 502. A meaning value is set in the duplicate inspection IP address 503 as an IP address to be subjected to the duplicate inspection.

  FIG. 6 shows elements of a duplicate notification packet used for notifying duplicate IP addresses used in the Auto IP procedure. The terminal that detects duplication of the IP address and transmits the duplication notification packet indicates the physical address of the other party that notifies the destination physical address 600 of the duplication of the IP address, the source physical address 601 indicates the physical address of the own terminal, and the packet type. A value indicating a duplicate notification packet is set in the identifier 602, and an IP address where duplication is detected is set in the duplicate notification IP address 603.

  FIG. 10 is a functional block diagram showing a configuration of functions related to IP address setting of a terminal that performs IP address duplication resolution by the Auto IP procedure.

  At startup, the terminal randomly selects an IP address to be used by its own terminal by the IP address selection unit 1008 and passes the selected IP address to the duplicate inspection packet generation unit 1007. The duplicate check packet generation means 1007 generates the duplicate check packet shown in FIG. 5 in order to check whether or not the delivered IP address is duplicated in the network, and sets the duplicate check IP address 503 as the IP address selection means. The IP address passed from 1008 is set.

  When the duplicate check packet generation unit 1007 generates a duplicate check packet, it transmits the packet to the network. At the same time, the duplicate notification packet wait timer 1004 is started.

  The packet receiving means 1000 receives a packet whose destination physical address is an identifier meaning broadcast, or a packet whose destination physical address is the physical address of its own terminal, and passes it to the received packet analysis means 1002.

  FIG. 7 is a flowchart showing an operation procedure of the received packet analysis means 1002. When a packet is passed from the network, the received packet analysis unit 1002 determines the type of the received packet from the packet type identifier in step 701. Next, in step 702, if a duplicate check packet is received, the duplicate check packet processing in step 703 is performed. If not, the process proceeds to step 704. In step 704, if a duplicate notification packet is received, the duplicate notification packet is processed in step 705. If not, the process proceeds to step 706. If the packet is neither a duplicate check packet nor a duplicate notification packet in step 706, the packet is transferred to the received packet processing means 1003 in FIG. Received packet processing means 1003 performs appropriate processing according to the type of packet.

  FIG. 8 is a flowchart showing a detailed procedure of the duplicate inspection packet process in step 703 in FIG.

  When the received packet analysis unit 1002 receives the duplicate check packet, in step 801, the duplicate check IP address 503 of the received duplicate check packet overlaps with the IP address of the own terminal held in the wireless setting storage area 220 of FIG. In step 802, the IP address and the transmission source physical address 501 of the received duplicate check packet are passed to the duplicate notification packet generation means 1006 in FIG. The duplicate notification packet generation unit 1006 generates the duplicate notification packet of FIG. 6 and sets the physical address and IP address passed from the received packet analysis unit 1002 to the destination physical address 600 and the duplicate notification IP address 603, respectively. A packet is transmitted from the transmission unit 1001.

  FIG. 9 is a flowchart showing a detailed procedure of the duplicate notification packet processing in step 705 in FIG.

  When the received packet analysis unit 1002 receives the duplicate notification packet, the received packet analysis unit 1002 detects that the IP address selected by the IP address selection unit 1008 in FIG. 10 has already been used. In step 901, whether the duplicate notification packet wait timer 1004 is operating. If it is in operation, the process proceeds to step 902. If it is not in operation, the process is terminated. In step 902, it is determined that the IP address is not yet determined, and the duplicate notification packet wait timer 1004 is stopped. In step 903, the IP address selection unit 1008 is started again.

  When the duplicate notification packet wait timer 1004 in FIG. 10 times out, the duplicate notification packet wait timer timeout processing means 1005 stores the selected IP address in the wireless setting storage area 220 and starts communication with the IP address. To do.

  Next, referring to FIG. 1, an IP addressing sequence in the present embodiment will be described.

  First, in step 101, the duplicate inspection packet generation unit 1007 generates a duplicate inspection packet. Next, in step 102, the controller 212 determines the magnitude of the wireless communication transmission output. If the transmission output is already large, the process proceeds to step 104. If the transmission output is not large, the process proceeds to step 103. In step 103, the transmission output of wireless communication is increased by the controller 212 so that the duplicate inspection packet can be broadcast over a wider range.

  Next, in step 104, the generated duplication check packet is transmitted from the packet transmission means 219. In the next step 105, it is determined whether or not a duplicate notification packet is received from surrounding terminals. If a duplicate notification packet is received, the process proceeds to step 106, where the duplicate notification packet processing described with reference to FIG. 9 is performed. When the duplicate notification packet processing is performed, the process returns to step 101 to generate a duplicate check packet again. On the other hand, when the duplicate notification packet is not received, the selected IP address is used. Since the IP address to be used is determined, in step 106, the transmission output of wireless communication is returned to the original state by the controller 212.

  As described above, in the addressing sequence using Auto IP, the transmission output of wireless communication is made larger than that during normal data transmission. Also, when a duplicate notification packet is received and a duplicate check packet is transmitted again, the transmission output of wireless communication is made larger than that during normal data transmission. As a result, it is possible to broadcast a duplicate check packet over the entire communicable range of the corresponding digital camera.

  Thereby, in a wireless ad hoc network, collision of IP addresses during data communication due to movement of a terminal can be prevented.

(Second Embodiment)
In the second embodiment, a method for controlling reception sensitivity when receiving a duplicate notification packet will be described with reference to FIG.

  First, in step 1100, the duplicate inspection packet generation unit 1007 generates a duplicate inspection packet. In step 1101, the generated duplicate inspection packet is transmitted from the packet transmission unit 219. In the next step 1102, the controller 212 determines the magnitude of wireless communication reception sensitivity. If the reception sensitivity is already high, the process proceeds to step 1104. If the reception sensitivity is not high, the process proceeds to step 1103. In step 1103, the reception sensitivity of the wireless communication is increased by the controller 212 so that duplicate inspection packets can be received from a wider range.

  In step 1104, it is determined whether duplicate notification packets have been received from surrounding terminals. If a duplicate notification packet is received, the process advances to step 1105 to perform the duplicate notification packet processing described with reference to FIG. When the duplicate notification packet processing is performed, the process returns to step 1100 to generate a duplicate check packet again. On the other hand, when the duplicate notification packet is not received, the selected IP address is used. Since the IP address to be used is determined, in step 1106, the controller 212 returns the wireless communication transmission output to the original state.

  As described above, the reception sensitivity of the wireless communication is increased when the duplicate notification packet is received as compared to the normal data reception.

  Thereby, the duplication notification packet can be received over the entire communicable range of the corresponding digital camera.

  Thereby, in a wireless ad hoc network, collision of IP addresses during data communication due to movement of a terminal can be prevented.

  Moreover, you may implement combining 1st Embodiment and 2nd Embodiment. That is, the transmission output of wireless communication is made larger than that at the time of normal data transmission, and the reception sensitivity of wireless communication is made larger at the time of receiving the duplicate notification packet than at the time of normal data reception.

The flowchart figure which showed the operation | movement procedure of the IP addressing sequence of the radio | wireless communication terminal in 1st Embodiment. 1 is a block diagram illustrating a configuration of a digital camera and a configuration of a printer according to an embodiment. Diagram showing an example of a wireless ad hoc network Diagram showing an example of IP address collision when a terminal moves to a wireless ad hoc network Explanatory drawing which showed the element of the duplication inspection packet in one Embodiment Explanatory drawing which showed the element of the duplication notification packet in one Embodiment The flowchart figure which showed the operation | movement procedure of the received packet analysis process of the radio | wireless communication terminal in one Embodiment The flowchart figure which showed the operation | movement procedure of the reception test | inspection packet process of the radio | wireless communication terminal in one Embodiment The flowchart figure which showed the operation | movement procedure of the reception notification packet process of the radio | wireless communication terminal in one Embodiment 1 is a functional block diagram showing a functional configuration related to IP address setting of a wireless communication terminal according to an embodiment; The flowchart figure which showed the operation | movement procedure of the IP addressing sequence of the radio | wireless communication terminal in 2nd Embodiment.

Explanation of symbols

201 Digital Camera 202 Signal Processing Unit 203 RAM
204 Imaging unit 205 CF
206 Display memory 207 LCD monitor 208 ROM
209 SW control unit 210 Operation member 211 Wireless communication interface 212 Controller 213 RF module 214 Antenna 215 Flash ROM
216 USB interface 217 CPU
218 Packet reception means 219 Packet transmission means 220 Wireless setting storage area 231 Printer 232 Image memory 233 Buffer memory 234 Driver 235 Printer head 236 ROM
237 Paper transport unit 238 Flash ROM
239 Power SW
240 USB interface 241 Wireless communication interface 242 Controller 243 RF module 244 Antenna 245 CPU
246 Packet receiving means 247 Packet transmitting means 248 Wireless setting value storage area

Claims (6)

A wireless communication device,
A control unit that controls the operation of each unit of the wireless communication device;
In the control unit, wireless transmission means for transmitting a data packet or control packet generated by data or a control command;
Wireless receiving means for receiving a data packet or a control packet transmitted by a communication partner;
Transmission control means for controlling the signal reach of packets transmitted from the wireless transmission means,
The transmission control means controls the signal arrival range at the time of test packet transmission for determining its own address to be wider than at the time of data packet transmission,
The wireless communication device, wherein the wireless transmission means transmits the inspection packet within the signal reachable range. The wireless communication device according to claim 1,
A reception control means for controlling a signal reception range of a packet received by the wireless reception means;
The reception control means controls the signal reception range at the time of receiving a notification packet to notify that its own address is duplicated to be wider than at the time of receiving the data packet,
The wireless communication device, wherein the wireless reception means receives the notification packet within the signal reception range. A transmission control method in a wireless communication apparatus, comprising: a wireless transmission means for transmitting an inspection packet for determining its own address to a communication partner; and a transmission control means for controlling a signal reach when transmitting the inspection packet. And
Generating the inspection packet and sending it to the wireless transmission means and the transmission control means;
In the transmission control means, performing a control to make a signal reach range at the time of transmission of the inspection packet wider than at the time of data packet transmission;
Transmitting the inspection packet within the signal reachable range by the wireless transmission means. After sending an inspection packet to determine your address to the communication partner,
Receiving control in a wireless communication apparatus, including a wireless receiving unit that receives a notification packet for notifying that the address of the communication partner is duplicated, and a reception control unit that controls a signal reception range when the notification packet is received A method,
Notifying the reception control means of inspection packet transmission to the communication partner;
In the reception control means, performing a control so that a signal reception range at the time of receiving the notification packet is wider than that at the time of receiving the data packet;
And a step of waiting for reception of the notification packet within the signal reception range by the wireless reception means. Computer for transmission control in a wireless communication apparatus, including wireless transmission means for transmitting an inspection packet for determining its own address to a communication partner, and transmission control means for controlling a signal reach when transmitting the inspection packet A computer-readable storage medium storing a program to be executed by the computer,
Generating the inspection packet and sending it to the wireless transmission means and the transmission control means;
In the transmission control means, performing a control to make a signal reach range at the time of transmission of the inspection packet wider than at the time of data packet transmission;
A computer-readable storage medium storing a program for causing a computer to execute the step of transmitting the inspection packet within the signal reachable range by the wireless transmission means. After sending an inspection packet to determine your address to the communication partner,
Receiving control in a wireless communication apparatus, including a wireless receiving unit that receives a notification packet for notifying that the address of the communication partner is duplicated, and a reception control unit that controls a signal reception range when the notification packet is received A computer-readable storage medium storing a program for causing a computer to execute
Notifying the reception control means of inspection packet transmission to the communication partner;
In the reception control means, performing a control so that a signal reception range at the time of receiving the notification packet is wider than that at the time of receiving the data packet;
A computer-readable storage medium storing a program for causing a computer to execute the step of waiting for reception of the notification packet within the signal reception range by the wireless reception means.

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