JP2009094885A - Radio apparatus and connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rapidly select a frequency channel, while suppressing the deterioration of communication quality. <P>SOLUTION: A control part 36 regulates priority for each of a plurality of frequency channels, and performs a connection operation with a radio apparatus being a communication object in order from a frequency channel with the highest priority. When the connection is successfully performed, the control part 36 stops the connection operation with respect to the frequency channel where no connection operation is performed yet. When connection is successfully performed in the control part 36, an RF part 30 and a modulating/demodulating part 32 perform communication with the communication apparatus being the communication object through the use of the connected frequency channel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a connection technique, and more particularly to a radio apparatus and a connection method for setting a frequency channel.

In a wireless communication system, when signals having the same carrier frequency are transmitted from a plurality of transmission apparatuses, interference occurs between these signals. As a result, a signal may not be received. In order to improve communication quality, a carrier frequency with less interference should be used (see, for example, Patent Document 1).
JP 7-264100 A

  In order to use a frequency channel with less interference, for example, a frequency channel used by a base station apparatus installed in the vicinity is investigated, and a frequency channel to be used is determined based on the investigation result. Therefore, a frequency channel is systematically set in advance in the base station apparatus. Alternatively, the base station apparatus performs carrier sense and voluntarily selects a frequency channel with less interference. In the former case, the communication quality deteriorates when the interference in the set frequency channel is large. In the latter case, a certain period of time is required for carrier sense, and it is difficult to start communication immediately after activation.

  A display system in which an in-vehicle camera is installed in a vehicle such as an automobile and an image captured by the in-vehicle camera is displayed on a monitor in the vehicle has been put into practical use. In such a display system, when an in-vehicle camera is installed behind the vehicle, the driver can check the rear image on the in-vehicle monitor when the vehicle is backed, and convenience is improved. On the other hand, in order to simplify the installation of the display system, a wireless communication system may be used for video transmission from the in-vehicle camera to the in-vehicle monitor. At this time, as described above, a frequency channel with less interference should be used, but a shortening of a period from the start to the start of communication is required. Furthermore, when this radio | wireless communications system uses the ISM band, it also receives the interference from another radio | wireless communications system.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a communication technique for selecting a frequency channel at high speed while suppressing deterioration of communication quality.

  In order to solve the above-described problem, a wireless device according to an aspect of the present invention defines a priority order for each of a plurality of frequency channels, and performs a connection operation with a wireless device that is a communication target in order from a frequency channel having a higher priority order. And a communication unit that executes communication with the wireless device to be communicated using the connected frequency channel when the connection is successful in the control unit. The control unit prescribes the stay period in each frequency channel, and performs the connection operation on the frequency channel with the highest priority after receiving the instruction to start the connection operation until the end of the stay period. The first processing unit to be executed, and when the connection is not successful in the first processing unit, until the connection is successful, the frequency channel is sequentially shifted to the lower priority order until each stay period ends. A second processing unit that executes each connection operation, and a third processing unit that stops the connection operation for the frequency channel that is not performing the connection operation when the connection is successful in the first processing unit or the second processing unit. Is provided.

  According to this aspect, the connection operation is executed in order from the frequency channel with the highest priority, and when the connection is successful, the connection operation on the remaining frequency channels is stopped. Can be selected.

  The control unit may define a priority order related to the frequency channel for each of a plurality of wireless devices to be communicated. In this case, since the priority order is defined for each of the plurality of wireless devices, it is possible to suppress the deterioration of the collision probability of the connection request.

  The control unit may reset the priority order based on the frequency channel used in the past communication. In this case, since the priority order is reset based on the results of past communication, the priority order of the actually used frequency channel can be increased.

  Another aspect of the present invention is a connection method. In this method, the priority order is defined for each of a plurality of frequency channels, and the connection operation with the wireless device to be communicated is executed in order from the frequency channel with the highest priority order. The connection operation with respect to the frequency channel not performing the operation is stopped, and the communication with the wireless device to be communicated is performed using the connected frequency channel. A step of prescribing a stay period in each frequency channel, and executing a connection operation on the frequency channel with the highest priority from when an instruction to start the connection operation is received until the stay period ends; When the connection is not successful, until the connection is successful, the system sequentially shifts to the lower priority frequency channel and executes each connection operation until each stay period ends, and the connection A step of stopping the connection operation for the frequency channel for which the connection operation is not executed when the connection is successful.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, a frequency channel can be selected at high speed, suppressing the deterioration of communication quality.

  Before describing the present invention specifically, an outline will be given first. Embodiments of the present invention relate to a communication system for transmitting video captured by an in-vehicle camera to a display device. The communication system includes a wireless device connected to the in-vehicle camera (hereinafter referred to as “first wireless device”) and a wireless device connected to the display device (hereinafter referred to as “second wireless device”). When the driver enters the back gear, the in-vehicle camera and the first wireless device are activated. After the first wireless device and the second wireless device set the frequency channel, video is transmitted from the first wireless device to the second wireless device. Since it is necessary for the driver to immediately check the video after entering the back gear, a frequency channel with less interference should be set between the first radio apparatus and the second radio apparatus at high speed. In order to cope with this, the communication system according to the present embodiment executes the following processing.

  The communication system defines priorities for each of a plurality of frequency channels and defines a stay period in each frequency channel in the connection process. A connection process between the first wireless device and the second wireless device (hereinafter, the first wireless device and the second wireless device are collectively referred to as “wireless device”) is started from the time when the back gear is engaged. The The wireless device attempts to connect on the highest priority frequency channel. If the connection is successful, the wireless device starts communication immediately. On the other hand, if the connection is not successful, the wireless device attempts to connect on each frequency channel while decreasing the priority order. If the connection is successful, the wireless device stops the connection process for the remaining frequency channel and starts communication immediately.

  FIG. 1 shows a configuration of a communication system 100 according to an embodiment of the present invention. The communication system 100 includes a first wireless device 10 a, a second wireless device 10 b, a camera 12, a display device 14, and a control device 16 that are collectively referred to as the wireless device 10. The communication system 100 is installed in the vehicle 20. Here, the right side of FIG. The camera 12 is installed at the rear part of the vehicle 20 so as to photograph the rear of the vehicle 20. The camera 12 performs encoding such as JPEG (Joint Photographic Experts Group) or MPEG (Moving Picture Experts Group) on the captured video, and then encodes the encoded video data (hereinafter simply referred to as “video”). It outputs to the 1st radio | wireless apparatus 10a. The camera 12 receives an instruction to start photographing through the control device 16 when the driver puts in the back gear. The camera 12 is activated when it receives the instruction, and then starts photographing. In this way, the camera 12 captures and outputs an image over the timing when the gear is in the back gear.

  The first radio apparatus 10a is connected to the camera 12 at one end and is connected to the second radio apparatus 10b at the other end. Here, the connection between the first wireless device 10a and the camera 12 is made via a cable, and the connection between the first wireless device 10a and the second wireless device 10b is made via a wireless network. Similar to the camera 12, the first wireless device 10 a receives a connection start instruction via the control device 16 when the driver puts in the back gear. Upon receiving the connection start instruction, the first wireless device 10a executes connection processing with the second wireless device 10b after being activated. If the connection is successful, the first wireless device 10a transmits the video from the camera 12 to the second wireless device 10b. Here, a plurality of frequency channels are defined between the first radio apparatus 10a and the second radio apparatus 10b, and the first radio apparatus 10a and the second radio apparatus 10b have any frequency in the connection process. Select a channel. Details of such processing will be described later.

  The second radio apparatus 10b is connected to the first radio apparatus 10a at one end and is connected to the display apparatus 14 at the other end. Here, the connection between the second wireless device 10b and the display device 14 is made through a cable. Similar to the first wireless device 10a, the second wireless device 10b receives a connection start instruction via the control device 16 when the driver puts in the back gear. In addition, as described above, the second wireless device 10b receives the video from the first wireless device 10a after executing the connection process with the first wireless device 10a. The second wireless device 10b outputs the received video to the display device 14.

  Upon receiving the video from the second wireless device 10b, the display device 14 decodes the video and displays the decoded video (hereinafter simply referred to as “video”) on a display (not shown). The display device 14 may also serve as a display unit of the navigation system. However, since a known technique may be used as the navigation system, description thereof is omitted here. The control device 16 controls the operations of the wireless device 10 and the camera 12. The control device 16 is connected to an ECU (Electric Control Unit: not shown) of the vehicle 20 and receives from the ECU that the user has put in the back gear. Thereafter, the control device 16 outputs an instruction to start photographing to the camera 12 and outputs an instruction to start connection to the wireless device 10.

  FIG. 2 shows the configuration of the wireless device 10. The wireless device 10 includes an RF unit 30, a modem unit 32, an IF unit 34, and a control unit 36. Here, common functions of the first radio apparatus 10a and the second radio apparatus 10b will be described first, and then processing performed in each of the first radio apparatus 10a and the second radio apparatus 10b will be described.

  The RF unit 30 receives a radio frequency signal via an antenna as a reception process. The RF unit 30 converts the received radio frequency signal into an intermediate frequency signal. In addition, the RF unit 30 generates a baseband signal by performing quadrature detection on the intermediate frequency signal. Further, the RF unit 30 outputs a digitized baseband signal (hereinafter simply referred to as “baseband signal”) by performing analog / digital conversion on the baseband signal. Since the baseband signal generally has an in-phase component and a quadrature component, two signal lines should be shown. However, for the sake of clarity, only one signal line is shown here.

  The RF unit 30 receives a baseband signal from the modem unit 32 as a transmission process. The RF unit 30 performs digital / analog conversion on the baseband signal to output an analogized baseband signal (hereinafter simply referred to as “baseband signal”). The RF unit 30 generates an intermediate frequency signal by orthogonally modulating the baseband signal. Further, the RF unit 30 converts the intermediate frequency signal into a radio frequency signal, amplifies it, and transmits it from the antenna.

  As a reception process, the modem unit 32 receives the baseband signal from the RF unit 30 and demodulates the baseband signal. The modem unit 32 outputs the demodulation result to the IF unit 34. As a transmission process, the modem unit 32 receives information from the IF unit 34 and modulates the information. The modem unit 32 outputs the modulation result to the RF unit 30 as a baseband signal. Here, as the modulation scheme in the modem unit 32, for example, a known technique such as QPSK (Quadrature Phase Shift Keying) may be used. In addition, the modem unit 32 may execute FEC (Forward Error Correction) and ARQ (Automatic Repeat Request), but the description thereof is omitted here.

  The IF unit 34 receives a demodulation result from the modem unit 32 as a reception process. The IF unit 34 outputs the demodulation result to the outside. For example, the IF unit 34 of the second wireless device 10b outputs the received demodulation result to the display device 14 (not shown). The IF unit 34 receives information from the outside as a transmission process. For example, the IF unit 34 of the first wireless device 10a receives an image from the camera 12 (not shown). The IF unit 34 outputs the received information to the modem unit 32.

The control unit 36 controls the operation of the wireless device 10. When receiving a connection start instruction from the control device 16 (not shown), the control unit 36 activates the RF unit 30 and the modem unit 32 and then executes connection processing. The control unit 36 defines a priority order for each of the plurality of frequency channels. Here, the priority order is defined in common between the first radio apparatus 10a and the second radio apparatus 10b. FIG. 3 shows a data structure of a priority table stored in the control unit 36. As shown, a priority column 200 and a frequency channel column 202 are included. In the priority order column 200, priorities are shown as “1”, “2”, and “N”. In the frequency channel column 202, frequency channels corresponding to the priority order are indicated as “f ₁ ”, “f ₂ ”, and “f _N ”. Returning to FIG. The control unit 36 defines in advance the stay period in each frequency channel in the connection process. The stay period is also defined in common between the first radio apparatus 10a and the second radio apparatus 10b. The stay period for each frequency channel may be set to a common value or an individual value.

The control unit 36 executes the connection process on the frequency channel with the highest priority, for example, “f ₁ ” in FIG. 3 during the period from the reception of the connection start instruction to the end of the stay period. The connection process will be specifically described. The control unit 36 of the first radio apparatus 10 a transmits a connection request signal via the modem unit 32 and the RF unit 30. When receiving the connection request signal via the RF unit 30 and the modem unit 32, the control unit 36 of the second radio apparatus 10 b transmits a response signal via the modem unit 32 and the RF unit 30. When receiving the response signal via the RF unit 30 and the modem unit 32, the control unit 36 of the first wireless device 10a recognizes a successful connection with the second wireless device 10b. On the other hand, the control unit 36 of the first radio apparatus 10a may transmit the connection request signal a plurality of times during the stay period if the response signal cannot be received. In order to execute the above processing, the control unit 36 has a counter (not shown), and operates the counter after receiving a connection start instruction. In the stay period, when the control unit 36 of the first radio apparatus 10a does not receive the response signal and the control unit of the second radio apparatus 10b does not receive the connection request signal, the connection process on the frequency channel has failed. Is done.

When the connection process fails, the control unit 36 shifts to the next highest priority frequency channel, for example, “f ₂ ” in FIG. Execute. Further, the control unit 36 repeatedly executes the connection process while sequentially shifting to the lower priority frequency channels until the connection is successful. That is, the control unit 36 executes connection processing with the wireless device 10 to be communicated in order from the frequency channel with the highest priority. Note that, when the connection is successful, the control unit 36 stops the connection process for the frequency channels for which the connection process has not been performed. That is, when the connection is successful, the control unit 36 causes the RF unit 30 and the modem unit 32 to immediately execute communication, thereby shortening the period until the communication starts. As a result, the RF unit 30 and the modem unit 32 perform communication with the wireless device 10 to be communicated using the connected frequency channel. Specifically, the modulation / demodulation unit 32 and the RF unit 30 of the first radio apparatus 10a transmit video, and the RF unit 30 and the modulation / demodulation unit 32 of the second radio apparatus 10b receive video.

  Note that the control unit 36 also has a function of performing carrier sense and selecting a frequency channel with a small amount of interference, and when there is no frequency channel successfully connected in the above processing, the control unit 36 Perform career sense. Even during communication, the control unit 36 performs carrier sense and searches for another frequency channel when the amount of interference in the frequency channel being used becomes larger than the threshold value. In accordance with the result, the control unit 36 shifts to another frequency channel.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it is realized by a program having a communication function loaded in the memory. Describes functional blocks realized by collaboration. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

The operation of the communication system 100 configured as above will be described. FIG. 4 is a sequence diagram illustrating a procedure of connection processing in the communication system 100. The first radio apparatus 10a receives a connection start instruction (S10), and the second radio apparatus 10b also receives a connection start instruction (S12). The first radio apparatus 10a sets the frequency channel to “f ₁ ” (S14), and the second radio apparatus 10b also sets the frequency channel to “f ₁ ” (S16). The first radio apparatus 10a transmits a connection request signal to the second radio apparatus 10b (S18). Thereafter, the stay period ends in the first radio apparatus 10a (S20), and the stay period also ends in the second radio apparatus 10b (S22).

The first radio apparatus 10a sets the frequency channel to “f ₂ ” (S24), and the second radio apparatus 10b also sets the frequency channel to “f ₂ ” (S26). The first radio apparatus 10a transmits a connection request signal to the second radio apparatus 10b (S28). Thereafter, the stay period ends in the first radio apparatus 10a (S30), and the stay period also ends in the second radio apparatus 10b (S32). The first radio apparatus 10a sets the frequency channel to “f ₃ ” (S34), and the second radio apparatus 10b also sets the frequency channel to “f ₃ ” (S36). The first radio apparatus 10a transmits a connection request signal to the second radio apparatus 10b (S38). When receiving the connection request signal, the second radio apparatus 10b transmits a response signal to the first radio apparatus 10a (S40). The first wireless device 10a transmits the video to the second wireless device 10b (S42).

  FIG. 5 is a flowchart illustrating a procedure of connection processing in the wireless device 10. When receiving the connection start instruction (S60), the control unit 36 selects the frequency channel with the highest priority (S62). The RF unit 30 and the modem unit 32 execute a connection process (S64), and if the connection is successful (Y in S66), execute the communication (S80). On the other hand, if the connection is not successful (N in S66) and the stay period has not ended (N in S68), the process returns to Step 64. If the stay period has ended (Y in S68), if a low-priority frequency channel can be used (Y in S70), the control unit 36 changes the frequency channel (S72) and returns to step 64. If the low priority frequency channel cannot be used (N in S70), the RF unit 30 and the modem unit 32 execute carrier sense (S74) and execute connection processing (S76). If the connection is successful (Y in S78), the RF unit 30 and the modem unit 32 perform communication (S80). If the connection is not successful (N in S78), the control unit 36 concludes that the connection has failed (S82).

  FIG. 6 is a flowchart illustrating a communication processing procedure after connection in the wireless device 10. If communication is not finished (N in S100), the RF unit 30 and the modem unit 32 detect the amount of interference in the currently used frequency channel. If the amount of interference is not greater than the threshold value (N in S102), the process returns to step 100. If the amount of interference is larger than the threshold value (Y in S102), the RF unit 30 and the modem unit 32 perform carrier sense (S104), and change the frequency channel based on the result (S106). Thereafter, the process returns to step 100. If the communication is terminated (Y in S100), the process is terminated.

  Another embodiment will be described below. In the embodiment, two wireless devices 10 are installed in the vehicle 20, but in another embodiment, three or more wireless devices 10 are installed in the vehicle 20. Since only one wireless device 10 is connected to the display device 14, a situation is assumed here in which the wireless device 10 is connected to each of the plurality of cameras 12. For example, a third wireless device 10c and a fourth wireless device 10d that are not shown in FIG. 1 are further included, and these request connection to the second wireless device 10b. Moreover, after connection, they transmit an image | video with respect to the 2nd radio | wireless apparatus 10b. In such a situation, the control unit 36 of the second radio apparatus 10b defines the priority order regarding the frequency channel for each of the radio apparatuses 10.

For example, the first radio apparatus 10a, _{"f 1", "f 2",} order the priority of the _{"f 3"} is defined, the third radio apparatus 10c, _{"f 2", "f 3} ”,“ F ₁ ”in the order of“ f ₁ ”, and the priority order is defined in the order of“ f ₃ ”,“ f ₁ ”,“ f ₂ ”for the fourth radio apparatus 10 d. That is, the table shown in FIG. 3 is prepared for each wireless device 10. The same rule is also applied to the control unit 36 of the first wireless device 10a, the third wireless device 10c, and the fourth wireless device 10d. Note that the connection start instruction for the second wireless device 10b includes information about the wireless device 10 to be communicated, and the control unit 36 of the second wireless device 10b sends the information to the wireless device 10 included in the information. Accordingly, the priority order is specified. By setting in this way, the second radio apparatus 10b can execute connection processing in parallel with the plurality of radio apparatuses 10. Further, the collision probability of the connection request signal at that time can be improved. Since the connection process may be the same as in the embodiment, description thereof is omitted here.

  Still another embodiment will be described. In yet another embodiment, the control unit 36 resets the priority order based on the frequency channel used in the past communication. Specifically, the priority of the frequency channel used for the previous communication is made highest. The control unit 36 changes the table shown in FIG. By setting in this way, it becomes easy to use the frequency channel used so far. Since the connection process may be the same as in the embodiment, description thereof is omitted here.

  Still another embodiment will be described. Yet another embodiment relates to processing performed in conjunction with the connection processing described so far. The vehicle 20 is provided with at least one IC (Integrated Circuit) for controlling various processes. Such an IC manages the state of a device to be controlled and its own failure. Depending on the contents of the state, it is better to notify the driver or the like early. In order to accommodate this, yet another embodiment is constructed.

  FIG. 7 shows the configuration of a first radio apparatus 10a according to still another embodiment of the present invention. The first radio apparatus 10a is the same type as the radio apparatus 10 shown in FIG. 2, and the first IC 50a, the second IC 50b, and the third IC 50c, which are collectively referred to as IC 50, are connected to the first radio apparatus 10a. The IC 50 controls arbitrary processing, receives the detection result of a sensor (not shown), and controls the operation of each part (not shown) of the vehicle 20. The IC 50 collects information on the state of the sensor and each unit (hereinafter referred to as “state information”). The IC 50 is requested to notify the state information from the first radio apparatus 10a at the timing when the first radio apparatus 10a is activated. When the IC 50 receives the request, it outputs the collected state information to the first wireless device 10a.

  As described above, the first radio apparatus 10a is activated upon receiving a connection start instruction. In addition, after the first wireless device 10a is activated, the first wireless device 10a requests the IC 50 to notify the state information, and the first wireless device 10a receives the state information from the IC 50. Thereafter, as described above, the first radio apparatus 10a executes connection processing with the second radio apparatus 10b (not shown). If the connection is successful, the first wireless device 10a transmits status information to the second wireless device 10b. The second wireless device 10b outputs the received status information to the display device 14 (not shown). The display device 14 displays status information.

  FIG. 8 is a sequence diagram showing a procedure of connection processing in the communication system 100 according to still another embodiment of the present invention. The first radio apparatus 10a is powered on (S120). The first radio apparatus 10a requests notification of state information from the first IC 50a to the third IC 50c. The first IC 50a to the third IC 50c transmit state information to the first radio apparatus 10a (S122 to S126). The first radio apparatus 10a and the second radio apparatus 10b execute connection processing (S128). The first radio apparatus 10a notifies the state information to the second radio apparatus 10b (S130).

  FIG. 9 is a flowchart showing a procedure of connection processing in the first radio apparatus 10a. The first radio apparatus 10a collects state information (S150). The status information is collected in the IF unit 34 of FIG. If failure information is included in the state information (Y in S152), the control unit 36 stores the failure content (S154). If failure information is not included in the state information (N in S152), step 154 is skipped. The first radio apparatus 10a executes connection processing (S156). If the connection is successful (Y in S158), the first radio apparatus 10a notifies the second radio apparatus 10b of information (S160). On the other hand, if the connection is not successful (N in S158), the first radio apparatus 10a recognizes the failure (S162) and turns on an LED (Light Emitting Diode) (not shown), for example.

  According to the embodiment of the present invention, since the connection operation is executed in order from the frequency channel with the highest priority, deterioration of communication quality can be suppressed. Further, if the connection is successful, the connection operation on the remaining frequency channels is stopped, so that the frequency channels can be selected at high speed. Further, since the frequency channel is selected at high speed, video transmission can be immediately executed. In addition, since the video is transmitted immediately, the period from when the back gear is turned on until the video is displayed can be shortened. In addition, since the stay period is defined in advance, the frequency channel can be shifted smoothly even if the two wireless devices are not synchronized. In addition, since the stay period is only specified in advance, synchronization between the two wireless devices can be eliminated.

  Further, since the synchronization between the two wireless devices is not necessary, the processing can be simplified. Moreover, since the priority order is defined for each of the plurality of wireless devices, it is possible to suppress the deterioration of the collision probability of the connection request. In addition, since the priority order is reset based on the results of past communication, the priority order of the actually used frequency channel can be increased. Since the priority of the frequency channel used in the previous communication is made highest, the same frequency channel can be used in the next communication. Moreover, since the same frequency channel as the previous time is first selected, the probability of successful connection can be improved. In addition, since the success probability of connection is improved, the connection processing period can be shortened. Further, since the state information is transmitted at the time of connection, the contents of the state information can be grasped at an early stage. Moreover, the above location can be grasped.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, the control unit 36 causes the RF unit 30 and the modulation / demodulation unit 32 to perform carrier sense when connection processing in all frequency channels fails. However, the present invention is not limited to this. For example, when the connection process in all the frequency channels fails, the control unit 36 may automatically select a predetermined frequency channel. According to this modification, the frequency channel selection process can be simplified.

It is a figure which shows the structure of the communication system which concerns on the Example of this invention. It is a figure which shows the structure of the radio | wireless apparatus of FIG. FIG. 3 is a diagram illustrating a data structure of a priority table stored in the control unit of FIG. 2. It is a sequence diagram which shows the procedure of the connection process in the communication system of FIG. 3 is a flowchart showing a procedure of connection processing in the wireless device of FIG. 2. 3 is a flowchart illustrating a communication processing procedure after connection in the wireless device of FIG. 2. It is a figure which shows the structure of the 1st radio | wireless apparatus which concerns on another Example of this invention. It is a sequence diagram which shows the procedure of the connection process in the communication system of another Example of this invention. It is a flowchart which shows the procedure of the connection process in the 1st radio | wireless apparatus of FIG.

Explanation of symbols

  10 wireless device, 12 camera, 14 display device, 16 control device, 20 vehicle, 30 RF unit, 32 modem unit, 34 IF unit, 36 control unit, 50 IC, 100 communication system.

Claims (4)

A control unit that defines a priority order for each of a plurality of frequency channels, and executes a connection operation with a wireless device that is a communication target in order from a frequency channel having a higher priority order,
A communication unit that performs communication with the wireless device to be communicated using the connected frequency channel when connection is successful in the control unit;
The controller is
A stay period in each frequency channel is defined in advance, and the connection operation is performed in the frequency channel with the highest priority from when the instruction to start the connection operation is received until the stay period ends. A processing unit;
When the connection is not successful in the first processing unit, the connection operation is sequentially performed until the connection is successful, and each connection operation is executed until each stay period ends. A second processing unit;
A wireless device comprising: a third processing unit that stops a connection operation for a frequency channel that is not performing a connection operation when a connection is successful in the first processing unit or the second processing unit.   The radio apparatus according to claim 1, wherein the control unit defines a priority order related to a frequency channel for each of a plurality of radio apparatuses to be communicated.   The radio apparatus according to claim 1, wherein the control unit resets the priority order based on a frequency channel used in past communication. Priorities are defined for each of the multiple frequency channels, and the connection operation with the wireless device that is the communication target is executed in order from the frequency channel with the highest priority, and when the connection is successful, the connection operation is executed. A connection method for canceling a connection operation to a non-frequency channel and performing communication with the wireless device to be communicated using the connected frequency channel,
A step of prescribing a stay period in each frequency channel, and executing a connection operation on the frequency channel with the highest priority from when an instruction to start the connection operation is received until the stay period ends; ,
If the connection is not successful, until the connection is successful, sequentially transition to the lower priority frequency channel, and performing each connection operation until each stay period ends,
And a step of canceling the connection operation for the frequency channel not performing the connection operation when the connection is successful.

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