JP2006157680A - Device specification method and radio communications device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To specify a target device out of a number of detection devices through simple operation, without the need for a user to know the address, device class, power class and the like of the target device. <P>SOLUTION: An inquiry signal is transmitted to a plurality of peripheral devices at a first position, a response signal is received from each of the peripheral devices, an inquiry signal is transmitted to the plurality of peripheral devices at a second position that is different from the first position, and a response signal is received from each of the peripheral devices. A device, having a maximum difference between the reception levels of the response signal received at the first position and the second position, is specified as the target device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for specifying a target device from a plurality of peripheral devices capable of wireless communication.

  Generally, in order for a device having a communication function to connect to a target device, it is necessary to detect and specify the target device.

  As a method of specifying the target device, there is a method of specifying the counterpart device by performing cable connection in the initial setting. In this case, the operation is complicated such that a cable connection is required every time a different device is connected, and when there are a large number of initial registration devices, an operation for searching for a target device from a large number of registration devices becomes necessary. For this reason, in the case of an ad hoc connection in which a temporary connection is made to a device in front of the user, it is desirable to perform connection after detecting and specifying the target device wirelessly.

  As a first method of specifying the target device wirelessly, there is a method of searching for peripheral devices and specifying the target device from the detected plurality of devices by address information or device names. As the above search, an inquiry signal is transmitted to the peripheral device, and response signals for the inquiry signal from the peripheral device are collected.

  Specifically, for example, in the case of a wireless LAN defined by IEEE 802.11, the search side transmits probe request frames to peripheral devices, and collects probe response frames transmitted from the peripheral devices. Then, the address of the target device is selected from the collected probe response frames, and connection is made.

  In the case of Bluetooth (registered trademark), the search side device transmits an ID (identity) packet as an inquiry signal to the peripheral device. Then, FHS packets transmitted as response signals from the peripheral devices are collected. The FHS packet includes a source address, clock information, service type, device type information, and the like. Then, the address of the target device is selected from the collected FHS packets, and connection is made.

  This operation will be described with reference to the flowchart shown in FIG. The search side device repeatedly transmits the ID packet as an inquiry to the peripheral device for 2.56 seconds while changing the transmission channel (S101). When the peripheral device receives the ID packet in its own standby channel, it immediately transmits the FHS packet to the ID packet transmission source device, and the search side device receives this (S102). Here, the search-side device connects to each peripheral device based on the acquired peripheral device address and clock, acquires the name of the connected device, and then disconnects (S103). If it takes about 2 seconds to acquire one device name, it takes about 30 seconds when 15 peripheral devices are searched. Then, the device name list acquired in step S103 is displayed on the screen as the device name acquisition result (S104). The user searches for and selects a target device from the displayed device name list (S105). The target device is identified by the above procedure.

In addition, as a second method for specifying a target device wirelessly, there is a method using an index obtained by quantifying the signal strength of a received radio wave. For example, Patent Literature 1 discloses a method for selecting an optimal base station from a plurality of base stations. In Patent Document 1, when an average value of RSSI (Received Signal Strength Indication) measured a plurality of times exceeds a threshold value, a base station search is started.
JP 2003-188789 A

  In the above conventional example, the first method needs to know in advance the address or name of the connection destination device, and requires a complicated procedure of finding the address of the target device from among a large number of detected devices. Become. Usually, the address is expressed in hexadecimal notation and is often expressed as a 12-digit number string, and is difficult to identify visually. Therefore, as a means to replace this address, the device name of the detected device is obtained, and the device name It is also possible to search for the target device.

  However, in order to acquire the device name, it is necessary to connect in order for each detected device, acquire the device name, and then disconnect. For this reason, when a large number of devices are detected, it takes several tens of seconds to acquire the name, and there is a problem that it takes time.

  Also, in the printer or the like, the same device name may be added to devices of the same model. In this case, there is a problem that two identical device names are detected and cannot be distinguished.

  In contrast, the second method can be applied when the device to be detected can be selected from a plurality of equivalent devices such as an access point, but has different functions such as an access point and a printer. This method is not applicable when searching for a device having a specific function from among devices as a connection destination or when connecting to the nearest printer.

  In addition, when the transmission power of each device is different, simply having a large RSSI value does not necessarily mean that the device is in the vicinity, and thus there is a problem that a target device in the vicinity cannot be identified by the RSSI value.

  The present invention has been made to solve the above-described problems, and it is not necessary for the user to know the address, device class, power class, etc. of the target device, and the target device can be easily operated from among a large number of detection devices. The purpose is to make it identifiable.

  The present invention relates to a device specifying method in a wireless communication apparatus for specifying a target device from a plurality of peripheral devices capable of wireless communication, wherein an inquiry signal is transmitted to the plurality of peripheral devices, and a response signal is transmitted from each peripheral device. A first step of receiving, a second step of transmitting an inquiry signal again to the plurality of peripheral devices and receiving a response signal from each peripheral device after the first step, the first step, and And a specifying step of specifying a target device based on the response signal received in the second step.

  Further, the present invention is a wireless communication apparatus that identifies a target device from a plurality of peripheral devices capable of wireless communication, and transmits an inquiry signal to the plurality of peripheral devices and receives a response signal from each peripheral device. Inquiry means, and specifying means for performing an inquiry process by the inquiry means a plurality of times and specifying a target device based on response signals received in the first inquiry process and the second inquiry process, To do.

  According to the present invention, when a portable terminal connects to a nearby device, the closest device is identified by performing a device search twice: a position away from the target device and a proximity position. Is possible.

  Further, it is not necessary for the user to know the address, device class, transmission power level, etc. of the target device in advance, and it is possible to easily connect to the target device and to shorten the time required for connection.

  The best mode for carrying out the invention will be described below in detail with reference to the drawings.

  As Example 1, the device to be searched is a portable digital camera (hereinafter referred to as “camera”) with a built-in Bluetooth (registered trademark) function, and the device to be searched (target device) is arranged at a position 1 m away. A case where the printer has a built-in Bluetooth (registered trademark) function will be described as an example. In addition, it is assumed that the camera starts searching for a target device after setting the print mode.

  FIG. 2 is a diagram illustrating a positional relationship of each device in the first embodiment. As shown in FIG. 2, the search side device is a portable camera 201. A mobile phone 202 is located 10 cm away from the camera 201. For example, it is assumed that the camera 201 is in the user's hand and the mobile phone 202 is in the chest pocket of the user. Therefore, when the user moves, the camera 201 and the mobile phone 202 move while maintaining the same distance. The printer 203 is in front of the user, and the camera 201 and the printer 203 are separated by 1 m. Further, the printer 204 is installed at a position 2 m away from the camera 201 and also functions as an access point (AP) that provides a connection function between the wireless network and the wired network 205.

  FIG. 3 is a diagram illustrating an example of a configuration of a camera that is a search-side device. In FIG. 3, reference numeral 301 denotes an antenna. Reference numeral 302 denotes an RF (Radio Frequency) unit, which converts a baseband signal of a baseband unit described later and a 2.4 GHz radio signal. Transmission from the RF unit 302 to the antenna 301 is performed in odd time slots, and reception is performed in even time slots.

  One time slot is defined by 625 μsec. Further, the RF unit 302 detects RSSI (Received Signal Strength Indication) of a packet received in an even time slot, and notifies the detected RSSI value to the host CPU via a baseband unit (BB) and a controller which will be described later. .

  Reference numeral 303 denotes a baseband unit that handles digital signals for communication, and mainly performs modulation / demodulation. A controller 304 controls the radio unit and serves as a radio interface management and a communication interface with a host CPU described later. A host CPU 305 controls the entire camera 201.

  A storage unit 306 includes a RAM (Random Access Memory) in which a work area and various tables used when the host CPU 305 executes control, and a ROM (in which a control program and control data of the host CPU 305 are stored). Read Only Memory).

  A display unit 307 includes a liquid crystal display device for displaying a status display of the camera 201 and a setting input. Reference numeral 308 denotes an imaging unit, which includes a lens and a solid-state imaging device.

  FIG. 4 is a diagram illustrating an example of a configuration of a printer that is a target device. 4 are the same as 301 to 306 shown in FIG.

  In FIG. 4, reference numeral 407 denotes a display unit, which is composed of LEDs that indicate printing and communication states. Reference numeral 408 denotes a printing unit. In the first embodiment, the printing unit 408 is configured by an ink jet printing mechanism.

  In the above configuration, a process in which the camera 201 as a search-side device searches for peripheral devices and specifies the printer 203 as a target device will be described.

  FIG. 5 is a flowchart illustrating a method for specifying a target device according to the first embodiment. First, in step S501, the host CPU 305 of the camera 201 executes a control program stored in the storage unit 306, and sets the type of search target device based on the “print mode” that is the current camera state set by the user. The controller 304 is notified by designating the service class shown as imaging, the major device class as rendering, and the minor device class as printer. Thereby, the controller 304 sets the service class and device class described above.

  In step S <b> 502, the host CPU 305 of the camera 201 executes the control program stored in the storage unit 306 and notifies the controller 304 of an inquiry instruction. As a result, the controller 304 creates an ID packet for the peripheral device and transfers it to the baseband unit 303. On the other hand, the baseband unit 303 modulates the ID packet received from the controller 304 into a radio signal and transfers it to the RF unit 302. The RF unit 302 converts the signal into a 2.4 GHz signal, and continues transmission for 2.56 seconds while sequentially changing the channel. Thereby, the radio signal is radiated to the space via the antenna 301.

  On the other hand, the peripheral device intermittently performs an inquiry scan waiting for an ID packet. When an ID packet is received from the camera 201 on the reception channel during this scan, an FHS packet is immediately sent on the same channel. Send. In 2.56 seconds when the camera 201 transmits the ID packet, all of the mobile phone 202, the printer 203, and the printer 204 return responses, and in step S503, the camera 201 collects all the FHS packets.

  FIG. 6 is a diagram illustrating search results of peripheral devices collected by the camera 201 according to the first embodiment. As shown in FIG. 6, the number of detected devices is “3”, and the device type and RSSI value are attached to each address.

  Next, in step S504, it is determined whether a plurality of devices are detected. Here, since the number of detected devices of the printer, which is the device class set in the operation mode setting in step S501 described above, is “2”, a plurality of devices are detected, and the process proceeds to step S505. If a plurality of devices are not detected, this process is terminated.

  In step S505, since a plurality of devices are detected in response reception in step S503, the user brings the camera 201 close to the target device to a close range of about 10 cm. In step S506, the inquiry is executed again.

  The second inquiry is the same as the first inquiry in step S502, but the distance to the target device (printer 203) is different.

  FIG. 7 is a diagram illustrating the positional relationship of peripheral devices in the second inquiry. As shown in FIG. 7, the distance between the camera 201 and the mobile phone 202 does not change, but the distance between the printer 203 and the printer 203 is close to 10 cm. Similarly, the distance to the printer 204 is as close as 1 m.

  Thereafter, in step S507, a response from the peripheral device to the second inquiry is received. This second response reception is the same as the first response reception in step S503, but the distance from the target device is different as shown in FIG.

  FIG. 8 is a diagram illustrating the second result of the peripheral devices collected by the camera 201 according to the first embodiment. As shown in FIG. 8, the number of detected devices is “3”, and the device type and RSSI value are attached to each address.

  In step S508, the device type is a printer and the difference between the RSSI values at the same address is calculated from the results of the first response reception and the second response reception. The calculation results are shown in FIG.

  FIG. 10 is a diagram illustrating RSSI values obtained by attenuation in free space at 2.4 GHz from the transmission power and actual distance of each device in the first embodiment. In the first embodiment, the values shown in FIG. 10 are used.

  Next, in step S509, the host CPU 305 determines the address 0x123456789A01, which is the device with the largest RSSI value, as the target device, sets the printer 203 to be connected to execute printing from the camera 201 as the target device, and sets the target device. End device identification.

  As described above, according to the first embodiment, the user having the largest difference in RSSI value among the device types set at the start of the search is set as the target device, so that the user can easily find the target device from the address value. It is possible to specify the target device in a short period of time without performing a simple operation and making an inquiry of 2.56 seconds twice.

  In the first embodiment, the second inquiry is executed close to the target device, but the first inquiry may be performed near the target device, and the second inquiry may be performed at a position slightly away from the target device.

  In addition, when using a highly directional antenna, it is possible to substitute the directivity direction toward the target device instead of bringing the camera close to the target device.

  Next, Embodiment 2 according to the present invention will be described in detail with reference to the drawings. In the second embodiment, a case where the type of the target device is not set before the search and the target device cannot be detected when searching at the close position will be described as an example. Therefore, when a plurality of corresponding devices finally become candidates, the user manually determines based on the type or name of the device.

  Further, in the second embodiment, the transmission power of the target device is as large as 20 dBm, and those that cannot be detected due to excessive reception power at positions close to each other (several tens of centimeters) are positions that are far away (several meters). However, the received signal strength is higher. Even in this case, since the received signal strength is about −40 dBm, it is possible to determine that an excessive received signal error has occurred in the class 1 device by setting the threshold at a distant position to −40 dBm.

  The arrangement of peripheral devices at the time of the first inquiry in the second embodiment is the same as that in FIG. 2 of the first embodiment, and the arrangement of peripheral devices at the second inquiry is the same as that in FIG. 7 of the first embodiment. The configuration of the camera as the device is the same as that in FIG. 3 of the first embodiment, and the configuration of the printer as the target device is the same as that in FIG.

  FIG. 11 is a flowchart illustrating a method for specifying a target device according to the second embodiment. First, in step S1101, the host CPU 305 of the camera 201 executes a control program stored in the storage unit 306, and notifies the controller 304 of an inquiry command. As a result, the controller 304 creates an ID packet for the peripheral device and transfers it to the baseband unit 303. On the other hand, the baseband unit 303 modulates the ID packet received from the controller 304 into a radio signal and transfers it to the RF unit 302. The RF unit 302 converts the signal into a 2.4 GHz signal, and continues transmission for 2.56 seconds while sequentially changing the channel. Thereby, the radio signal is radiated to the space via the antenna 301.

  On the other hand, the peripheral device intermittently performs an inquiry scan waiting for an ID packet. When an ID packet is received from the camera 201 on the reception channel during this scan, an FHS packet is immediately sent on the same channel. Send. In 2.56 seconds when the camera 201 transmits the ID packet, all of the mobile phone 202, the printer 203, and the printer 204 return responses, and in step S1102, the camera 201 collects all FHS packets.

  FIG. 12 is a diagram illustrating search results of peripheral devices collected by the camera 201 according to the second embodiment. As shown in FIG. 12, the number of detected devices is “3”, and the device type and RSSI value are attached to each address.

  Next, in step S1103, the user brings the camera 201 close to the target device to a close range of about 10 cm. In step S1104, the inquiry is executed again.

  This second inquiry is the same as the first inquiry in step S1101, but the distance to the target device (printer 203) is different.

  FIG. 7 is a diagram illustrating the positional relationship of peripheral devices in the second inquiry. As shown in FIG. 7, the distance between the camera 201 and the mobile phone 202 does not change, but the distance between the printer 203 and the printer 203 is close to 10 cm. Similarly, the distance to the printer 204 is as close as 1 m.

  Thereafter, in step S1105, a response from the peripheral device to the second inquiry is received. This second response reception is the same as the first response reception in step S1102, but the distance from the target device is different as shown in FIG.

  FIG. 13 is a diagram illustrating the second result of the peripheral devices collected by the camera 201 according to the second embodiment. As shown in FIG. 13, the number of detected devices is “3”, and a device type and an RSSI value are attached to each address.

  Next, in step S1106, the device type is a printer and the difference between RSSI values at the same address is calculated from the results of the first response reception and the second response reception. The calculation results are shown in FIG.

  FIG. 15 is a diagram illustrating RSSI values obtained by attenuation in free space at 2.4 GHz from the transmission power and actual distance of each device in the second embodiment. In the second embodiment, the values shown in FIG. 15 are used.

  In step S1107, the host CPU 305 determines whether there is a device that cannot calculate the RSSI difference. If there is a device whose RSSI difference cannot be calculated, the process advances to step S1108 to determine whether or not the RSSI value in the first response reception of the device whose RSSI value cannot be calculated is within a threshold. In the second embodiment, it is determined that the device (printer 203) having the address 0x123456789A01 cannot calculate the RSSI value, the RSSI value of the first response is −20 dBm, and exceeds the threshold value −40 dBm, and the process proceeds to step S1110. move on. If there are a plurality of devices whose RSSI values cannot be calculated and a plurality of devices exceeding the threshold value are detected in step S1108, the detected plurality of devices are left as candidate target devices.

  If there is no device that cannot calculate the RSSI difference in step S1107, or if the RSSI value in the first response reception of the device that cannot calculate the RSSI value does not exceed the threshold value in step S1108, the process proceeds to step S1109. It is determined whether or not a plurality of devices are detected. If a plurality of devices are not detected, the process advances to step S1110 to select a device having the largest RSSI value difference as a target device.

  If the threshold value is not exceeded in step S1108, the second inquiry position is not too close to be undetectable, and a device at a slightly distant position is caused by an increase in obstacles at the second inquiry position. This is the case when out of service area.

  However, a device having a difference of about 3 dB less than the device having the largest RSSI value difference is left as a target device candidate as a detection error.

  If a plurality of target device candidates are detected in step S1109, the process advances to step S1111 to display the address and device type on the display unit 307 and prompt the user to perform a manual selection operation. If necessary, device names are acquired only for the narrowed target device candidates, the user performs a selection operation using the device names, and the target device specifying operation is terminated.

  In the second embodiment, since the target device candidate is one of 0x123456789A01 in steps S1107 to S1109, this device is determined as the target device to which the camera 201 is connected, and the specific operation procedure of the target device is ended.

  As described above, when there is a device whose RSSI value cannot be detected in the proximity position of the target device, by setting this device as the target device, the target device can be specified due to excessive reception power due to too close proximity. It can be prevented from becoming impossible. By having this function, the user's operation does not increase as compared with the first embodiment.

  In addition, when a plurality of devices that are assumed to be target devices due to detection errors occur, the user can manually select from the limited candidates based on address information, device type, device name, etc. It is possible to prevent errors.

  Further, in the second embodiment, the second inquiry is performed close to the target device. However, the first inquiry may be performed near the target device, and the second inquiry may be performed at a position slightly away from the target device. . In that case, in step S1108, threshold determination may be executed for the second response value.

  Regarding misdetection due to interference with the wireless LAN, if the printer has a Bluetooth (registered trademark) function and a wireless LAN function compliant with IEEE802.11, a Bluetooth (registered trademark) inquiry scan is being executed. Since the wireless LAN signal is not transmitted, the camera 201 can always receive a response signal from the printer 203. For this reason, the interference problem does not occur.

  When there is a wireless LAN access point within the camera 201, packet data cannot be detected when the camera 201 responds to an inquiry, but only the RSSI level is increased. In such a case, when the inquiry time is doubled to 5.12 seconds, the target device scans again with a different inquiry scan channel, so that the detection is possible.

  Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), it is applied to an apparatus (for example, a copier, a facsimile machine, etc.) composed of a single device. It may be applied.

  Another object of the present invention is to supply a recording medium in which a program code of software realizing the functions of the above-described embodiments is recorded to a system or apparatus, and the computer (CPU or MPU) of the system or apparatus stores it in the recording medium. Needless to say, this can also be achieved by reading and executing the programmed program code.

  In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiment, and the recording medium storing the program code constitutes the present invention.

  As a recording medium for supplying the program code, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like is used. be able to.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a flowchart which shows the specific operation | movement of the conventional target device. FIG. 3 is a diagram illustrating a positional relationship between devices in Example 1. It is a figure which shows an example of a structure of the camera which is a device of the search side. FIG. 3 is a diagram illustrating an example of a configuration of a printer that is a target device. 3 is a flowchart illustrating a method for specifying a target device according to the first exemplary embodiment. FIG. 6 is a diagram illustrating search results of peripheral devices collected by the camera 201 according to the first embodiment. It is a figure which shows the positional relationship of the peripheral device in the 2nd inquiry. FIG. 6 is a diagram illustrating a second result of peripheral devices collected by the camera 201 in the first embodiment. It is a figure which shows the result of having calculated the difference of the RSSI value in Example 1. FIG. It is a figure which shows the RSSI value calculated | required by the attenuation in the free space in 2.4 GHz from the transmission power and actual distance of each device in Example 1. FIG. 10 is a flowchart illustrating a method for specifying a target device according to a second embodiment. It is a figure which shows the search result of the peripheral device which the camera 201 in Example 2 collected. It is a figure which shows the 2nd result of the peripheral device which the camera 201 in Example 2 collected. It is a figure which shows the result of having calculated the difference of the RSSI value in Example 2. FIG. It is a figure which shows the RSSI value calculated | required by attenuation in the free space in 2.4 GHz from the transmission power and actual distance of each device in Example 2. FIG.

Explanation of symbols

201 Portable Digital Camera 202 Mobile Phone 203 Printer 204 Printer (AP)
205 Network 301 Antenna 302 RF Unit 303 Baseband Unit (BB)
304 Controller 305 Host CPU
306 Storage unit 307 Display unit 308 Imaging unit 401 Antenna 402 RF unit 403 Baseband unit (BB)
404 Controller 405 Host CPU
406 Storage unit 407 Display unit 408 Printing unit

Claims (8)

A device specifying method in a wireless communication apparatus for specifying a target device from a plurality of peripheral devices capable of wireless communication,
A first step of transmitting an inquiry signal to a plurality of peripheral devices and receiving a response signal from each peripheral device;
After the first step, a second step of transmitting an inquiry signal to the plurality of peripheral devices again and receiving a response signal from each peripheral device;
And a specifying step of specifying a target device based on the response signals received in the first step and the second step. The first step is performed at a first position, and the second step is performed at a position different from the first position;
The device identification method according to claim 1, wherein either the first position or the second position is near a target device.   2. The device specifying method according to claim 1, wherein, in the specifying step, a device having the largest difference in reception level between the response signals received in the first step and the second step is specified as a target device.   In the specifying step, when the second position is close to the target device, the response signal can be detected at the first position, and the response signal cannot be detected at the second position, and the response is received at the first position. 2. The device identification method according to claim 1, wherein the device is identified as a target device when the reception level of the response signal exceeds a predetermined threshold.   The device identification method according to claim 1, wherein the directivity of the antenna is different between the first step and the second step. A wireless communication apparatus that identifies a target device from a plurality of peripheral devices capable of wireless communication,
Inquiry means for sending inquiry signals to a plurality of peripheral devices and receiving response signals from each peripheral device;
A wireless communication apparatus comprising: specifying means for specifying a target device based on response signals received by the first inquiry processing and the second inquiry processing, wherein inquiry processing by the inquiry means is performed a plurality of times .   The program for making a computer perform each procedure of the device identification method of Claim 1.   A computer-readable recording medium on which the program according to claim 7 is recorded.

Images