JP5022919B2 - Wireless communication apparatus, wireless communication method, and communication program - Google Patents

Description

  The present invention relates to a wireless communication apparatus, a wireless communication method, and a communication program of a wireless system that uses a frequency band in common with other wireless systems.

  Conventionally, a wireless communication system in which a plurality of wireless systems use a frequency band in common is known. In this wireless communication system, a wireless device with a low priority performs carrier detection of a shared frequency band, and transmits a signal when it is determined that the frequency band is not used by a wireless system with a high priority.

On the other hand, when a change in the internal radio wave environment of an information processing device (for example, a personal computer (PC)) becomes an interference signal for a wireless communication device that receives and transmits data from the information processing device, the generation of the interference signal is suppressed. A technique for avoiding deterioration of communication quality is known.
J. Mitola III, “Cognitive Radio for Flexible Mobile Multimedia Communications,” IEEE Sixth International Workshop on Mobile Multimedia Communications (MoMuC99), pp.3-10, Nov. 1999. JP 2004-112767 A

  The above-described conventional technology specifies the processing in the information processing device that affects the communication operation of the wireless communication device and controls its execution, non-execution, etc., which affects the operation of the information processing device, and the entire device As a result, there is a problem that the convenience of the user is impaired.

  The present invention provides a wireless communication apparatus, a wireless communication method, and a communication program capable of improving communication quality without affecting the operation of an external information processing apparatus in cognitive wireless communication.

A wireless communication device according to an aspect of the present invention includes:
A wireless communication device that performs wireless communication using an antenna,
Carrier sense means for performing carrier sense for one or more frequency channels predetermined via the antenna;
A connection means for connecting to an external information processing apparatus;
Operation detecting means for detecting whether or not the external information processing apparatus is operating;
First measuring means for measuring the first carrier level of each frequency channel one or more times using the carrier sensing means when the external information processing apparatus is not operating;
For each measurement of the first carrier level for each frequency channel, a carrier that generates carrier sense information indicating whether each frequency channel is available or indicating the measured first carrier level of each frequency channel Sense information generating means;
Storage means for storing the carrier sense information of each frequency channel;
Data acquisition means for acquiring transmission data from the external information processing device when the external information processing device is operating;
Second measuring means for measuring a second carrier level of each of the frequency channels using the carrier sensing means when the transmission data is acquired;
Carrier determination means for determining whether or not each of the frequency channels is available;
Data transmission means for transmitting the transmission data via the antenna using the frequency channel determined to be usable by the carrier determination means,
The carrier determination means includes
Determining that the frequency channel is available when a second carrier level of the frequency channel is less than a predetermined threshold;
When the second carrier level of the frequency channel is equal to or greater than the predetermined threshold value, it is determined whether or not the frequency channel can be used by using carrier sense information corresponding to the frequency channel. .

A wireless communication method as one aspect of the present invention includes:
A wireless communication method executed in a wireless communication device connected to an external information processing device,
An operation detecting step for detecting whether or not the external information processing apparatus is operating;
A first measurement step of measuring the first carrier level of each frequency channel one or more times by performing carrier sense for each of the frequency channels when the external information processing apparatus is not operating;
For each measurement of the first carrier level for each frequency channel, a carrier that generates carrier sense information indicating whether each frequency channel is available or indicating the measured first carrier level of each frequency channel A sense information generation step;
Storing the carrier sense information of each frequency channel in a storage device;
A data acquisition step of acquiring transmission data from the external information processing device when the external information processing device is operating;
A second measurement step of measuring a second carrier level of each frequency channel by performing carrier sense on one or more predetermined frequency channels when the transmission data is acquired;
A carrier determination step of determining whether each of the frequency channels is available;
A data transmission step of transmitting the transmission data using the frequency channel determined to be usable by the carrier determination step;
With
The carrier determination step includes
Determining that the frequency channel is available when a second carrier level of the frequency channel is less than a predetermined threshold;
When the second carrier level of the frequency channel is equal to or greater than the predetermined threshold value, it is determined whether or not the frequency channel can be used using carrier sense information corresponding to the frequency channel. .

A communication program as one aspect of the present invention is:
A communication program executed in a computer connected to an external information processing apparatus,
An operation detecting step for detecting whether or not the external information processing apparatus is operating;
A first measurement step of measuring the first carrier level of each frequency channel one or more times by performing carrier sense for each of the frequency channels when the external information processing apparatus is not operating;
For each measurement of the first carrier level for each frequency channel, a carrier that generates carrier sense information indicating whether each frequency channel is available or indicating the measured first carrier level of each frequency channel A sense information generation step;
Storing the carrier sense information of each frequency channel in a storage device;
A data acquisition step of acquiring transmission data from the external information processing device when the external information processing device is operating;
A second measurement step of measuring a second carrier level of each frequency channel by performing carrier sense on one or more predetermined frequency channels when the transmission data is acquired;
A carrier determination step of determining whether each of the frequency channels is available;
A data transmission step of transmitting the transmission data using the frequency channel determined to be usable by the carrier determination step;
With
The carrier determination step includes
Determining that the frequency channel is available when a second carrier level of the frequency channel is less than a predetermined threshold;
When the second carrier level of the frequency channel is equal to or greater than the predetermined threshold value, it is determined whether or not the frequency channel can be used by using carrier sense information corresponding to the frequency channel. .

  According to the present invention, it is possible to improve communication quality without affecting the operation of an external information processing apparatus in a cognitive radio communication system.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing a wireless communication system A in which a wireless communication apparatus A according to an embodiment of the present invention performs wireless communication, and other wireless systems B, B ′, and C.

  The radio communication system A is a cognitive radio system that shares a frequency band with the radio system B and is allowed to use the frequency band only when other radio systems are not using the frequency band. The wireless system B may be located in a geographically overlapping position with the wireless communication system A, or may be located in a geographically distant place as shown as a wireless system B '. The wireless system B and the wireless system C are, for example, a W-CDMA (Wideband-Division Multiple Access) system, a PDC (Personal Digital Cellular) system, a GSM (Global Standard for Mobile Communication) system E such as an E80 system such as a Global Standard for Mobile Communications (I) system. MAN (Metropolitan Area Network), LAN (Local Area Network) such as IEEE 802.11, ship radio, radar, fixed microwave system, and the like. Since the wireless communication system A is allowed to use a frequency with a lower priority than the wireless system B, the wireless communication device 11 belonging to the wireless communication system A interferes with the wireless communication performed by the wireless device 12 belonging to the wireless system B. Do not give.

  FIG. 2 shows a plurality of frequency channels B1, B2, B3, B4, B5... Bi in the frequency band 10 allocated to the radio system B, and a plurality of frequencies in the frequency band 11 allocated to the radio system C. Channels C1, C2, C3,..., C (j−1), Cj are shown. The radio communication apparatus 11 belonging to the radio communication system A shown in FIG. 1 can use the frequency channels B2, B3, B4, and B5 assigned to the radio system B shown in FIG. Since A is permitted to use a frequency with a lower priority than the wireless system B, the wireless communication device 11 belonging to the wireless communication system A uses, for example, the frequency channel B3. If it is, the signal must not be transmitted at a frequency corresponding to the frequency channel B3. As described above, the wireless communication device 11 belonging to the wireless communication system A does not transmit a signal on the frequency channel when the wireless system with a high priority starts using the frequency channel and does not use the frequency channel. By transmitting a signal only in the determined frequency channel, communication is continued while preventing interference with wireless communication performed in another wireless system.

  In FIGS. 1 and 2, examples of the wireless system B and the wireless system C are shown as wireless systems in which the wireless communication system A shares a frequency band. However, the number of wireless systems in which the wireless communication system A shares a frequency band There is no limitation, and for example, the frequency band may be shared with a wireless system D, a wireless system E, or the like different from the wireless system B or the wireless system C. Also in this case, the wireless communication system A is permitted to use the frequency band with a lower priority than the wireless system D, the wireless system E, and the like.

  FIG. 3 is a block diagram showing an example of a schematic configuration of the wireless communication apparatus 11 according to an embodiment of the present invention. 1 includes an input terminal 1, an antenna 30, a timer 31, a control unit 32, a carrier detection unit 33, a wireless communication unit 34, a power reception unit 35, a memory 36, and an internal power source 37.

  The power receiving unit 35 is supplied with power from an external information processing apparatus (hereinafter simply referred to as an external apparatus) via the input terminal 1. The input terminal 1 corresponds to connection means for connecting to an external device. The power receiving unit 35 distributes the power supplied from the external device to each element of the wireless communication device 11. The internal power supply 37 is charged by the power supplied from the external device. When there is no power supply from the external device (when the external device is not operating), the internal power supply 37 is used to supply power to each element.

  The control unit 32 controls the carrier detection unit 33, the wireless communication unit 34, the power reception unit 35, and the timer 31. The control unit 32 is an operation detection unit that detects whether or not the external device is in operation based on whether or not power is supplied to the power reception unit 35. Data acquisition means for acquiring transmission data.

  The carrier detection unit 33 uses carrier sense means for performing carrier sense via the antenna 30 for one or more predetermined frequency channels, and when the external device is not operating, using the carrier sense means for each frequency channel. First measuring means for measuring the first carrier level at least once, and second measuring means for measuring the second carrier level of each frequency channel using carrier sensing means when the transmission data is acquired. And comprising. In addition, the carrier detection unit 33 receives carrier sense information indicating whether each frequency channel is usable or the measured first carrier level of each frequency channel for each measurement by the first measurement unit. Carrier sense information generating means for generating based on the first carrier level and a predetermined threshold value.

  The memory 36 stores the first and first carrier levels of each frequency channel measured by the first and first measurement units of the carrier detection unit 33, the carrier sense information generated by the carrier sense information generation unit, etc. Various data generated by the processing of the communication device are stored.

  The control unit 32 determines whether or not each frequency channel can be used before transmitting transmission data during operation of the external device based on each second carrier level and a predetermined threshold value. Carrier determining means for determining is provided. More specifically, the carrier determination unit determines that the frequency channel is available when the second carrier level of the frequency channel measured during the operation of the external device is equal to or less than the predetermined threshold value. When the second carrier level of the frequency channel exceeds a predetermined threshold value, the carrier sense information corresponding to the frequency channel is used to determine whether it can be used. For example, in the case where the carrier sense information is the presence / absence of availability acquired during non-operation for each frequency channel, when the carrier sense information corresponding to the frequency channel indicates availability, it is determined that the frequency sense channel is available. The fact that the carrier sense information indicates that the carrier sense information can be used may indicate that, for example, a predetermined percentage of the carrier sense information among the plurality of carrier sense information acquired for the frequency channel can be used. When the carrier sense information indicates the measured first carrier level of each frequency channel, it can be used when the ratio of the first carrier level below the threshold satisfies a predetermined value for the frequency channel. Can be determined.

  The wireless communication unit 34 includes data transmission means for transmitting transmission data via the antenna 30 using the frequency channel determined to be usable by the carrier determination means of the control unit 32.

  FIG. 4 is a flowchart illustrating an example of wireless communication processing based on carrier sense performed by the wireless communication device 11.

  The control unit 32 in FIG. 3 determines whether the power supply from the external device is ON or OFF based on the information from the power reception unit 35 (step S40).

  If the power supply from the external device is OFF, the control unit 32 determines whether or not it is a carrier sense timing based on the timing information from the timer 31 (step S41).

  In step S41, if it is not carrier sense timing, it waits until carrier sense timing.

  On the other hand, if it is carrier sense timing in step S41, a control signal is output to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S42).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S43), and compares the measured carrier level with a predetermined threshold value (step S44). ).

  If the measured carrier level is greater than or equal to a predetermined threshold value, carrier detection is determined and the result is stored in the memory 36 (step S45). On the other hand, if the measured carrier level is smaller than a predetermined threshold, carrier non-detection is determined and the result is stored in the memory 36 (step S45).

  The control unit 32 determines whether there is an unmeasured frequency channel among the predetermined frequency channels (step S46), and if there is an unmeasured frequency channel, repeats the processing from step S42.

  If it is determined in step S46 that carrier measurement has been completed for all the predetermined frequency channels, it is determined whether or not the power supply from the external device has been turned ON (step S47). If the power supply is off, the processes after step S41 are repeated. On the other hand, if the power supply from the external device is turned ON in step S47, the process proceeds to step S48 and subsequent steps.

  When the power supply from the external device is ON in step S40 or when the power supply from the external device is turned ON in step S47, a communication start request is input from the external device (step S48). The control unit 32 outputs a control signal to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S49).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S50), and compares the measured carrier level with a predetermined threshold value (step S51). ).

  If the measured carrier level is equal to or higher than a predetermined threshold (Yes in S52), the carrier sense result in the frequency channel at the time of power supply OFF stored in the memory 36 is referred to (Step S53). If no carrier is detected in the frequency channel when power supply is turned off, it is determined that the frequency channel is a frequency channel that can be used for wireless communication (step S54).

  On the other hand, in step S53, if a carrier is detected in the frequency channel when power supply is turned off, it is determined that the frequency channel is a frequency channel that cannot be used for wireless communication (step S55).

  In step S52, when the measured carrier level is smaller than a predetermined threshold (No in step S52), carrier non-detection is determined (step S52), and the frequency channel can be used for wireless communication. It is determined that the frequency channel is correct (step S54). That is, the frequency channel in which no carrier is detected in the carrier sense performed while the power supply is ON is determined to be a frequency channel capable of wireless communication regardless of the carrier sense result during the power supply OFF period.

  When the carrier measurement in one frequency channel is completed, it is determined whether or not there is an unmeasured frequency channel among the predetermined frequency channels (step S56). If there is an unmeasured frequency channel, step S49 is determined. The subsequent processing is repeated.

  If it is determined in step S56 that carrier measurement has been completed for all frequency channels determined in advance, wireless communication is performed on the frequency channel determined to be capable of wireless communication in step S54 (step S57). .

  It is determined whether or not a communication end request is input from the external device (step S58). If a communication end request is input, the processing ends. On the other hand, if the communication end request is not input from the external device, the processing from step S49 is repeated.

  As described above, even if the carrier is detected during the period when the power supply from the external device is ON, if the carrier is not detected during the time when the power supply from the external device is OFF, the power supply from the external device is performed. It can be determined that the carrier detection during the ON period is a result caused by noise output from the external device and not a result caused by the signal of the primary system. Therefore, by using the frequency channel determined in this way for wireless communication, broadband communication can be performed, and thus the throughput of the system can be improved.

  Here, it is possible to improve detection accuracy by using the latest carrier sense result as the carrier sense result during the period when the power supply from the external device is OFF in step S53. This will be specifically described with reference to FIG.

  FIG. 5 is a diagram showing an example of carrier sense results of a plurality of frequency channels at each time, which are measured in the period when the power supply from the external device is OFF by the wireless communication device 11 and stored in the memory 36. FIG. 5 shows the results of carrier sensing for the eight frequency channels from frequency channel 1 to frequency channel 8 from time t0 to t5 during the period when the power supply from the external device is OFF. Represents carrier non-detection. In the example shown in FIG. 5, the carrier is detected at all times in the frequency channel 7 and the carrier is not detected until time t1 in the frequency channel 3, but the carrier is detected after time t2. . This indicates that in the frequency channel 3, the primary system has started using the frequency band from time t2. Therefore, the detection accuracy can be improved by using the latest data at time t5 as the carrier sense result to be referred to.

  FIG. 6 is a flowchart illustrating an example of wireless communication processing performed by the wireless communication device 11 when the latest carrier sense result at the time of power supply OFF is used. The flowchart shown in FIG. 6 is obtained by adding step S60 to the flowchart shown in FIG. Therefore, the overlapping description is omitted.

  In the flowchart shown in FIG. 6, the processes from step S40 to step S52 are the same as those in the flowchart shown in FIG. In step S52 of the flowchart shown in FIG. 6, when the measured carrier level is equal to or higher than a predetermined threshold value, the latest carrier sense result in the frequency channel at the time of power supply OFF stored in the memory 36 is displayed. Obtain (step S60). The latest carrier sense result in the frequency channel at the time of power supply OFF is referred (step S53). If no carrier is detected, it is determined that the frequency channel is a frequency channel that can be used for wireless communication (step S54). . On the other hand, if a carrier is detected in the latest carrier sense in the frequency channel at the time of power supply OFF in step S53, it is determined that the frequency channel is a frequency channel that cannot be used for wireless communication (step S55).

  An example of processing when the latest carrier sense result at the time of power supply OFF is used will be further described with reference to FIG.

  FIG. 7 is a timing chart of carrier sense performed by the wireless communication device 11. In FIG. 7, reference numeral 70 denotes a state in which power supply from the external device is OFF, and 71 denotes a state in which power supply from the external device is ON. Reference numeral 72 denotes carrier sense at time t0 when the power supply from the external apparatus is OFF, reference numeral 73 denotes carrier sense at time t1 when the power supply from the external apparatus is OFF, and reference numeral 74 denotes power supply from the external apparatus is OFF. The carrier sense at time t2 of the period, 75 is the carrier sense at time t3 when the power supply from the external device is OFF, 76 is the carrier sense at time t4 when the power supply from the external device is OFF, 77 is external Reference numeral 78 represents carrier sense at time t5 when power is supplied from the apparatus, and reference numeral 78 represents carrier sense at time t6 when power is supplied from the external apparatus.

  Compared with the carrier sense result at time t5, which is the latest carrier sense in the period when the power supply from the external device is OFF, with respect to the frequency channel in which the carrier is detected in the carrier sense 78 at the time t6 when the power supply from the external device is ON. If no carrier is detected in carrier sense at time t5, it can be determined that carrier detection in the frequency channel at time t6 is caused by noise due to the operation of the external device.

  Thus, when a carrier is detected in the carrier sense during the period when the power supply from the external device is ON, by using the latest carrier sense result (carrier sense information) during the period when the power supply from the external device is OFF, The detection accuracy of the primary system signal can be increased.

  Here, in the processing of the flowchart of FIG. 4 or FIG. 6, in the carrier sense (step S50 to step S52) after the start of communication, the frequency channel for which carrier non-detection is determined is detected by the carrier in the frequency channel when power is turned off. Even if it is, it is determined that the frequency channel can be used for wireless communication (step S54). This will be specifically described with reference to FIG.

  FIG. 8 shows an example of the carrier sense results of a plurality of frequency channels measured at a time when the wireless communication device 11 is in a period when the power supply from the external device is OFF and stored in the memory 36, and the power supply from the external device is ON. It is the figure which showed an example of the carrier sense result measured in the period. More specifically, in FIG. 8, for eight frequency channels from frequency channel 1 to frequency channel 8, the result of carrier sense from time t <b> 0 to t <b> 5 during the period when power supply from the external device is OFF, and power supply from the external device. Shows the result of carrier sense from time t6 to time t11 during the period of ON, where Yes represents carrier detection and No represents carrier non-detection. In the example shown in FIG. 8, in the frequency channel 3, the carrier is detected at all times during the period when the power supply from the external device is OFF and until time t9 when the power supply from the external device is ON. No carrier is detected from time t10 during the period when the power supply from is ON. This represents that in the frequency channel 3, the primary system has stopped using the frequency band from time t10. Therefore, at time t10 and time t11, the wireless communication device 11 determines that the frequency channel 3 is a frequency channel that can be used for wireless communication, and performs wireless communication on the frequency channel.

  As described above, even if the carrier is detected in a period in which the power supply from the external device is OFF, if the carrier is not detected in the period in which the power supply from the external device is ON, the primary system By using the frequency channel for wireless communication, broadband communication is possible, and the system throughput can be improved.

  Here, the carrier sense results held by the wireless communication device 11 in the memory 36 during the period when the power supply from the external device is OFF may be stored cumulatively, or may be sequentially overwritten with the latest carrier sense results. Good. An example of overwriting will be described with reference to FIG.

  FIG. 9 is a second diagram illustrating an example of carrier sense results of a plurality of frequency channels, which are measured in the period when the power supply from the external device is OFF and stored in the memory 36. In the example shown in FIG. 9, one region is held for each frequency channel, and the carrier sense result is overwritten on the region each time carrier sense is performed. Thereby, the carrier sense result described in the said area | region represents the latest carrier sense result always in the period when the electric power feeding from an external device is OFF. As a result, the memory area can be used efficiently.

(Second Embodiment)
FIG. 10 is a flowchart illustrating an example of carrier sense processing performed by the control unit 32 of the wireless communication device 11 illustrated in FIG. 3 while the power supply from the external device is OFF, which is performed by controlling the timer 31 and the carrier detection unit 33. It is. This process is characterized in that carrier sensing is performed at regular time intervals when power is turned off.

  The control unit 32 sets, in the timer 31, a fixed time interval of carrier sense that is stored in advance in the memory 36 and is performed during a period in which the power supply from the external device is OFF (step S80).

  When the time set from the control unit 32 has elapsed, the timer 31 outputs a signal to the control unit 32 (step S41).

  The control unit 32 outputs a control signal to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S42).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S43), and compares the measured carrier level with a predetermined threshold value (step S44). ).

  If the measured carrier level is greater than or equal to a predetermined threshold value, carrier detection is determined and the result is stored in the memory 36 (step S45).

  On the other hand, if the measured carrier level is smaller than a predetermined threshold, carrier non-detection is determined and the result is stored in the memory 36 (step S45).

  The control unit 32 determines whether there is an unmeasured frequency channel among the predetermined frequency channels (step S46), and if there is an unmeasured frequency channel, repeats the processing from step S42.

  If it is determined in step S46 that carrier measurement has been completed for all the predetermined frequency channels, it is determined whether or not the power supply from the external device has been turned ON (step S47). If the power supply is off, the processes after step S41 are repeated.

  On the other hand, if the power supply from the external device is changed to ON in step S47, the process ends.

  In this way, by performing carrier sense at regular time intervals when power is turned off, it is possible to always check and store the latest frequency usage status, that is, the presence or absence of a primary system signal.

(Third embodiment)
FIG. 11 is a diagram illustrating an example of carrier sense processing performed by the control unit 32 of the wireless communication device 11 illustrated in FIG. 3 by controlling the timer 31 and the carrier detection unit 33 during a period in which power supply from an external device is OFF. It is a second flowchart. In this process, when power is turned off, a threshold is set for the elapsed time from the time when the power is turned off, and the time interval for performing carrier sense is changed before and after this threshold elapsed time. It is characterized by. Hereinafter, this process will be described in detail.

  The control unit 32 sets a threshold elapsed time stored in the memory 36 in advance after the power supply from the external device is turned off to the timer 31 (step S90).

  Next, the control unit 32 sets, in the timer 31, a carrier sense time interval A performed before the threshold elapsed time after the power supply from the external device is turned off (step S91).

  Subsequently, the control unit 32 sets, in the timer 31, a carrier sense time interval B that is performed after the threshold elapsed time from when the power supply from the external device is turned off (step S92).

  The timer 31 first sets the carrier sense time interval A set by the control unit 32 (step S93).

  When the time interval A set by the control unit 32 elapses, the timer 31 outputs a signal to the control unit 32 (step S41).

  The control unit 32 outputs a control signal to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S42).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S43), and compares the measured carrier level with a predetermined threshold value (step S44). ).

  If the measured carrier level is greater than or equal to a predetermined threshold value, carrier detection is determined and the result is stored in the memory 36 (step S45).

  On the other hand, if the measured carrier level is smaller than a predetermined threshold, carrier non-detection is determined and the result is stored in the memory 36 (step S45).

  The control unit 32 determines whether there is an unmeasured frequency channel among the predetermined frequency channels (step S46), and if there is an unmeasured frequency channel, repeats the processing from step S42.

  If it is determined in step S46 that carrier measurement has been completed for all the predetermined frequency channels, it is determined whether or not the power supply from the external device has been turned ON (step S47). When the power supply is OFF, the timer 31 determines whether or not the threshold elapsed time set by the control unit 32 has elapsed (step S94).

  If the threshold elapsed time has not elapsed, the processing from step S41 is repeated. If the threshold elapsed time has elapsed, the timer 31 sets the time interval B as the carrier sense time interval. This is performed (step S95).

  On the other hand, when the power supply from the external device is changed to ON in step S47, this process is terminated.

  In this way, when power supply is turned off, a threshold value is set for the elapsed time from the time when power supply is turned off, and the time interval for performing carrier sense is changed before and after this threshold value elapsed time. Thus, carrier sensing during the power supply OFF period can be performed efficiently.

(Fourth embodiment)
FIG. 12 is a block diagram illustrating an example of a schematic configuration of the wireless communication apparatus 11 according to an embodiment of the present invention, in which a system clock 100 is added to the block diagram illustrated in FIG.

  FIG. 13 shows a carrier sensing process performed by the control unit 32 of the wireless communication apparatus 11 shown in FIG. 12 by controlling the timer 31, the carrier detection unit 33, and the system clock 100 during a period when the power supply from the external device is OFF. It is a 3rd flowchart which shows an example. This process is characterized in that the time interval of carrier sense when power supply from an external device is OFF is changed according to the time zone. Hereinafter, this process will be described in detail.

  The control unit 32 inquires the system clock 100 about the time zone (step S110). If the time zone C is output from the system clock, the control unit 32 sets the carrier sense time interval C stored in the memory 36 in advance in the timer 31. (Step S111). On the other hand, if the time zone output from the system clock is the time zone D in step S110, the carrier sense time interval D stored in advance in the memory 36 is set in the timer 31 (step S112).

  When the time set from the control unit 32 has elapsed, the timer 31 outputs a signal to the control unit 32 (step S41).

  The control unit 32 outputs a control signal to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S42).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S43), and compares the measured carrier level with a predetermined threshold value (step S44). ).

  If the measured carrier level is greater than or equal to a predetermined threshold value, carrier detection is determined and the result is stored in the memory 36 (step S45).

  On the other hand, if the measured carrier level is smaller than a predetermined threshold, carrier non-detection is determined and the result is stored in the memory 36 (step S45).

  The control unit 32 determines whether there is an unmeasured frequency channel among the predetermined frequency channels (step S46), and if there is an unmeasured frequency channel, repeats the processing from step S42.

  If it is determined in step S46 that carrier measurement has been completed for all the predetermined frequency channels, it is determined whether or not the power supply from the external device has been turned ON (step S47). If the power supply is off, the processes after step S110 are repeated.

  On the other hand, if the power supply from the external device is changed to ON in step S47, the process ends.

  As described above, by changing the time interval of the carrier sense when the power supply from the external device is OFF according to the time zone, it is possible to efficiently perform the carrier sense during the power supply OFF period.

(Fifth embodiment)
FIG. 14 is a block diagram showing an example of a schematic configuration of the wireless communication apparatus 11 according to an embodiment of the present invention, in which the connection lines of the control unit 32 and the memory 36 in the block diagram shown in FIG. 12 are connected bidirectionally. It is.

  FIG. 15 illustrates an example of carrier sense processing performed by the control unit 32 of the wireless communication device 11 illustrated in FIG. 14 by controlling the timer 31, the carrier detection unit 33, and the memory 36 during a period in which power supply from an external device is OFF. It is a 4th flowchart which shows this.

  The control unit 32 uses the timer 31 to acquire the elapsed time from the time when the power supply from the external device is turned off, and the time obtained by subtracting a predetermined offset time from the average value of the power supply OFF period acquired in advance. It is determined whether or not it has elapsed (step S130). A method of calculating the average value during the power supply OFF period will be described later.

  If the elapsed time from the time when the power supply from the external device is turned off has elapsed by subtracting a predetermined offset time from the average value of the power supply OFF period, the carrier sense stored in the memory 36 in advance is stored. The time interval E is set in the timer 31 (step S131).

  On the other hand, in step S130, if the elapsed time from the time when the power supply from the external device is turned off has not elapsed since the time obtained by subtracting a predetermined offset time from the average value of the power supply OFF period, the memory 36 is preliminarily stored. The stored carrier sense time interval F is set in the timer 31 (step S132). The time interval F is larger than the time interval E.

  When the time set from the control unit 32 has elapsed, the timer 31 outputs a signal to the control unit 32 (step S41).

  The control unit 32 outputs a control signal to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S42).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S43), and compares the measured carrier level with a predetermined threshold value (step S44). ).

  If the measured carrier level is greater than or equal to a predetermined threshold value, carrier detection is determined and the result is stored in the memory 36 (step S45).

  On the other hand, if the measured carrier level is smaller than a predetermined threshold, carrier non-detection is determined and the result is stored in the memory 36 (step S45).

  The control unit 32 determines whether there is an unmeasured frequency channel among the predetermined frequency channels (step S46), and if there is an unmeasured frequency channel, repeats the processing from step S42.

  If it is determined in step S46 that carrier measurement has been completed for all the predetermined frequency channels, it is determined whether or not the power supply from the external device has been turned ON (step S47). If the power supply is OFF, the processes after step S130 are repeated.

  On the other hand, when the power supply from the external device is changed to ON in step S47, this process is terminated.

  In this way, by predicting the time when the power supply is turned on based on the history of the past power supply OFF period, and performing carrier sense at a short time interval immediately before the time when the power supply is turned on, the latest carrier state is efficiently obtained. Can be obtained.

  FIG. 16 is a flowchart illustrating an example of processing in which the control unit 32 of the wireless communication apparatus 11 illustrated in FIG. 14 controls the power reception unit 35, the system clock 100, and the memory 36 to measure the average of the power supply OFF period. .

  The control unit 32 in FIG. 14 determines whether the power supply from the external device is ON or OFF based on the information from the power receiving unit 35 (step S40).

  When the power supply from the external device is OFF, the time when the power supply is OFF is stored in the memory 36. Here, for example, the time when the power supply is turned off is t10.

  In step S40, when the power supply from the external device is turned on, the control unit 32 reads the time when the power supply from the external device is turned off from the memory 36 (step S121), and the power supply from the external device is turned on. By subtracting the time when the power supply from the external device read from the memory is turned off from the time when the current time becomes, the period during which the power supply from the external device is turned off is calculated (step S122). Here, for example, if the time when the power supply from the external device is turned on is t11, the period during which the power supply from the external device is OFF is calculated as t11-t10. That is, the control unit 32 includes a non-operation period calculation unit that calculates a non-operation period from the time when the external device enters the non-operation state to the time when the external device enters the operation state.

  Subsequently, the control unit 32 reads the average value of the power supply OFF period from the memory (step S123), and updates the average value of the period when the power supply from the external device is OFF using the value calculated in step S122 ( Step S124).

  Further, the control unit 32 stores the updated average value in the memory 36 (step S125). The memory 36 includes history storage means for storing a history of the non-operation period (here, an average value).

  It is determined whether or not the wireless communication device 11 has been reset (step S126). If the wireless communication device 11 has been reset, the process ends. If not reset, the processes in and after step S40 are repeated.

(Sixth embodiment)
FIG. 17 is a flowchart illustrating an example of processing in which the control unit 32 of the wireless communication apparatus 11 illustrated in FIG. 14 determines an available frequency band. This process is characterized in that carrier sense is performed only once immediately after the power supply from the external device is turned off. Hereinafter, this process will be described in detail.

  The control unit 32 in FIG. 14 determines whether the power supply from the external device is ON or OFF based on the information from the power receiving unit 35 (step S40).

  When the power supply from the external device is turned off, the carrier detection unit 33 is controlled to perform carrier sense (step S140).

  Subsequently, the carrier sense result when the power supply from the external device is ON is read from the memory 36 (step S141), and can be used from the carrier sense result in step S140 and the carrier sense result when the power supply read in step S141 is ON. A correct frequency channel is determined (step S142). The specific process of step S142 is to use a frequency channel in which a carrier is detected in the carrier sense result when the power supply read from the memory in step S141 is ON, but no carrier is detected in the carrier sense in step S140. Judge as a channel.

  When the control unit 32 determines an available frequency channel, the control unit 32 stores the determined frequency channel in the memory 36 (step S143). Thereafter, the processes after step S40 (S140 to S143) are repeated.

  On the other hand, when the power supply from the external device is turned on in step S40, the memory 36 is referred to and it is determined whether there is information on available frequency channels (step S144).

  If there is information on available frequency channels, these frequency channels are used for wireless communication (step S145).

  The control unit 32 controls the carrier detection unit 33 to perform carrier sense (step S146), and stores the carrier sense result in the memory 36 (step S147). That is, the control unit 32 controls the carrier detection unit 33 to perform carrier sense immediately after the power supply is turned on. Immediately after the power supply is turned on, for example, there may be within a threshold time after the power supply is turned on.

  The control unit 32 determines a frequency channel to be used for wireless communication based on the carrier sense result in step S146 (step S148), but even if the frequency channel has a carrier detected in the carrier sense in step S146, the control unit 32 The frequency channels described in the available frequency channel list in S145 are used for wireless communication.

  The control unit 32 notifies the wireless communication unit 34 of available frequency channels and performs wireless communication (step S149). It is determined whether or not the wireless communication device 11 has been reset (step S150). If the wireless communication device 11 has been reset, the process ends. If not reset, the processes in and after step S40 are repeated.

  As described above, since the carrier sense is performed immediately after the power supply from the external device is turned off, the capacity of the internal power supply 37 is cut off while the power supply is turned off, and the carrier sense cannot be performed even once. The problem can be prevented. Further, since the carrier sense is performed only once, the capacity of the internal power source 37 can be effectively utilized. In addition, when the primary signal does not change with time (for example, a radar signal, a broadcast signal, a television signal, etc. is assumed), it is considered that the carrier sense result performed once is effective during the OFF period. The noise of the external device and the primary signal can be distinguished efficiently. In addition, by comparing the carrier sense result performed immediately after the power supply from the external device is turned off and the carrier sense result during the period when the power supply from the external device is on, the available frequency channel is determined, and the next power supply is performed. When is turned on, it can be determined that the frequency channel can be used for wireless communication, and the throughput of the system can be improved by broadband communication.

(Seventh embodiment)
FIG. 18 is a flowchart showing an example of wireless communication processing based on carrier sense in the wireless communication device 11, and is a flowchart obtained by adding the processing of step S160 and step S161 to the flowchart shown in FIG.

  The control unit 32 determines whether the power supply from the external device is ON or OFF based on the information from the power reception unit 35 (step S40).

  If the power supply from the external device is OFF, the control unit 32 determines whether or not it is a carrier sense timing based on the timing information from the timer 31 (step S41).

  In step S41, if it is not carrier sense timing, it waits until carrier sense timing.

  On the other hand, if it is carrier sense timing in step S41, a control signal is output to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S42).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S43), and compares the measured carrier level with a predetermined threshold value (step S44). ).

  If the measured carrier level is greater than or equal to a predetermined threshold value, carrier detection is determined and the result is stored in the memory 36 (step S45).

  On the other hand, if the measured carrier level is smaller than a predetermined threshold, carrier non-detection is determined and the result is stored in the memory 36 (step S45).

  The control unit 32 determines whether there is an unmeasured frequency channel among the predetermined frequency channels (step S46), and if there is an unmeasured frequency channel, repeats the processing from step S42.

  If it is determined in step S46 that carrier measurement has been completed for all the predetermined frequency channels, it is determined whether or not the power supply from the external device has been turned ON (step S47). If the power supply is off, the processes after step S41 are repeated.

  On the other hand, if the power supply from the external device is turned ON in step S47, the process proceeds to step S48 and subsequent steps.

  When the power supply from the external device is ON in step S40 or when the power supply from the external device is turned ON in step S47, a communication start request is input from the external device (step S48).

  The control unit 32 outputs a control signal to the carrier detection unit 33, and the carrier detection unit 33 sets a frequency channel for performing carrier sense (step S49).

  When the setting of the frequency channel is completed, the carrier detection unit 33 measures the carrier in the frequency channel (step S50), and compares the measured carrier level with a predetermined threshold value (step S51). ).

  If the measured carrier level is smaller than a predetermined threshold value, carrier non-detection is determined (step S52), and it is determined that the frequency channel is a frequency channel that can be used for wireless communication (step S52). S54).

  On the other hand, if the measured carrier level is greater than or equal to a predetermined threshold value in step S52, the carrier sense result in the frequency channel at the time of power supply OFF stored in the memory 36 is referred to (step S53). If no carrier is detected in the frequency channel when the power supply is turned off, the carrier measurement level described in the memory 36 (the level measured in the previous step S50; step S161 described later) is calculated from the carrier measurement level in step S50. It is determined whether or not the difference obtained by subtracting (see) is larger than a predetermined threshold value (second threshold value) (step S160). The carrier measurement level corresponds to, for example, the noise level of the external device when the primary system is not using the frequency channel, and when the primary system is using the frequency channel, the carrier level of the primary system + external Corresponds to the noise level of the device.

  When the difference is equal to or less than a predetermined threshold value, it is determined that the frequency channel is a frequency channel that can be used for wireless communication (step S54).

  After step S54, the carrier measurement level in the available frequency channel is stored in the memory (step S161). However, immediately after the power supply is turned on (for example, after “ON” in step S40 and before step S48), carrier sensing is performed on the frequency channel determined in advance in step S44 to perform carrier measurement (third carrier level). Is stored in the memory. The carrier detection unit 33 includes a third measurement unit that measures the third carrier level. Here, it is assumed that the frequency channel that is not carrier-detected when the power supply is turned off is not used by the primary system immediately after the power supply is turned on (the level of carrier measurement is the noise level of the external device).

  On the other hand, when the difference is larger than a predetermined threshold value, it is determined that the frequency channel is a frequency channel that cannot be used for wireless communication (step S55). That is, it is determined that the primary system has started using the frequency channel.

  In step S53, if a carrier is detected in the frequency channel when power supply is turned off, it is determined that the frequency channel is a frequency channel that cannot be used for wireless communication (step S55).

  When the carrier measurement in one frequency channel is completed, it is determined whether or not there is an unmeasured frequency channel among the predetermined frequency channels (step S56). If there is an unmeasured frequency channel, step S49 is determined. The subsequent processing is repeated.

  If it is determined in step S56 that carrier measurement has been completed for all the predetermined frequency channels, wireless communication is performed on the frequency channel determined to be usable in step S54 (step S57).

  It is determined whether or not a communication end request has been input from the external device (step S58). If a communication end request has been input, this process ends.

  On the other hand, if the communication end request is not input from the external device, the processing from step S49 is repeated.

  In this way, even in a frequency band that has been determined to be capable of wireless communication once, the primary signal can be detected by observing the change in the carrier sense level in the frequency band, thus causing interference to the primary system. Cognitive communication can be performed without

(Eighth embodiment)
FIG. 19 is a block diagram showing an example of a schematic configuration of the wireless communication apparatus 11 according to an embodiment of the present invention, in which the input terminal 2 is added to the control unit 32 in the block diagram shown in FIG.

  In the block diagram shown in FIG. 19, the power supply information of the external device is input from the input terminal 2 connected to the control unit 32. The power supply information of the external device is information regarding whether the power of the external device to which the wireless communication device 11 is connected is on or off, and corresponds to operation information indicating whether the external device is operating. To do. The control unit 32 includes an operation information receiving unit that receives operation information via the input terminal 2.

  In the first to seventh embodiments, the carrier sense is performed based on the ON / OFF of the external power supply input to the wireless communication device 11, but the wireless communication device 11 as in this embodiment. Carrier sensing may be performed based on power supply information of an external device input from the input terminal 2 instead of ON / OFF of power supply input from the outside.

  Note that the wireless communication device in each of the embodiments described above can also be realized by using, for example, a general-purpose computer device as basic hardware. That is, the timer, the control unit, the carrier detection unit, the wireless communication unit, and the system clock in the wireless communication device can be realized by causing a processor mounted on the computer device to execute a program. At this time, the wireless communication device may be realized by installing the above program in a computer device in advance, or may be stored in a storage medium such as a CD-ROM or distributed through the network. Thus, this program may be realized by appropriately installing it in a computer device. The memory can be realized by appropriately using a memory built in or externally attached to the computer device, a hard disk, or a storage medium such as a CD-R, CD-RW, DVD-RAM, DVD-R, or the like. .

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The block diagram which shows an example of schematic structure of the radio | wireless communications system A to which the radio | wireless communication apparatus 11 which is one Embodiment of this invention belongs. The figure which showed the several frequency channel in the frequency band 10 allocated to the radio | wireless system B, and the several frequency channel in the frequency band 11 allocated to the radio | wireless system C. The block diagram which shows an example of schematic structure of the radio | wireless communication apparatus 11 which is one Embodiment of this invention. The flowchart which shows an example of the radio | wireless communication process based on the carrier sense which the radio | wireless communication apparatus 11 performs. An example of the carrier sense result of the several frequency channel in each time which the radio | wireless communication apparatus 11 measured in the period when the electric power feeding from an external device is OFF. The 2nd flowchart which shows an example of the radio | wireless communication process based on the carrier sense which the radio | wireless communication apparatus 11 performs. The figure showing the timing chart of the carrier sense which the radio | wireless communication apparatus 11 performs. The figure which showed an example of the carrier sense result which the radio | wireless communication apparatus 11 measured in the period when the electric power feeding from an external device is OFF and ON. The 2nd figure which showed an example of the carrier sense result which the radio | wireless communication apparatus 11 measured in the period when the electric power feeding from an external device is OFF. The flowchart which shows an example of the carrier sense process performed in the period when the electric power feeding from an external device is OFF. The 2nd flowchart which shows an example of the carrier sense process performed in the period when the electric power feeding from an external device is OFF. The figure which added the system clock 100 to the block diagram shown in FIG. The 3rd flowchart which shows an example of the carrier sense process performed in the period when the electric power feeding from an external device is OFF. The figure which connected the connection part of the control part 32 and the memory of the block diagram shown in FIG. 12 bidirectionally. The 4th flowchart which shows an example of the carrier sense process performed in the period when the electric power feeding from an external device is OFF. The flowchart which shows an example of the process which measures the average of a power supply OFF period. 15 is a flowchart illustrating an example of processing in which the control unit 32 of the wireless communication apparatus 11 illustrated in FIG. 14 determines an available frequency band. The flowchart which added the process of step S160 and step S161 to the flowchart shown in FIG. The figure which added the input terminal 2 to the control part 32 of the block diagram shown in FIG.

Explanation of symbols

1: Input terminal (connection means)
2: Input terminal 11: Wireless communication device 31: Timer 32: Control unit (operation detection means, data acquisition means, carrier determination means, non-operation period calculation means)
33: Carrier detection unit (carrier sense means, first to third measurement means, carrier sense information generation means)
34: Wireless communication unit (data transmission means)
35: Power receiving unit 36: Memory (storage means, history storage means)
37: Internal power supply 100: System clock

Claims (13)

A wireless communication device that performs wireless communication using an antenna,
Carrier sense means for performing carrier sense for one or more frequency channels predetermined via the antenna;
A connection means for connecting to an external information processing apparatus;
Operation detecting means for detecting whether or not the external information processing apparatus is operating;
First measuring means for measuring the first carrier level of each frequency channel one or more times using the carrier sensing means when the external information processing apparatus is not operating;
For each measurement of the first carrier level for each frequency channel, a carrier that generates carrier sense information indicating whether each frequency channel is available or indicating the measured first carrier level of each frequency channel Sense information generating means;
Storage means for storing the carrier sense information of each frequency channel;
Data acquisition means for acquiring transmission data from the external information processing device when the external information processing device is operating;
Second measuring means for measuring a second carrier level of each of the frequency channels using the carrier sensing means when the transmission data is acquired;
Carrier determination means for determining whether or not each of the frequency channels is available;
Data transmission means for transmitting the transmission data via the antenna using the frequency channel determined to be usable by the carrier determination means,
The carrier determination means includes
Determining that the frequency channel is available when a second carrier level of the frequency channel is less than a predetermined threshold;
When the second carrier level of the frequency channel is equal to or greater than the predetermined threshold value, it is determined whether or not the frequency channel can be used by using carrier sense information corresponding to the frequency channel. Wireless communication device. The carrier determination means indicates that the latest carrier sense information among the carrier sense information obtained for a frequency channel in which a carrier level equal to or higher than a predetermined threshold is detected is available or less than the threshold. The radio communication apparatus according to claim 1, further comprising: determining that a frequency channel in which a carrier level equal to or greater than a predetermined threshold is detected is available. The wireless communication apparatus according to claim 1, wherein the first measurement unit performs measurement at regular time intervals. 4. The wireless communication according to claim 3, wherein the first measurement unit changes the value of the predetermined time interval according to an elapsed time from a time when the external information processing apparatus is in a non-operating state. Communication device. A system clock,
The wireless communication apparatus according to claim 3, wherein the first measurement unit changes the value of the certain time interval according to a time zone. A non-operation period calculation means for calculating a non-operation period from a time when the external information processing apparatus is in the non-operation state to a time when the external information processing apparatus is in the operation state;
History storage means for storing a history of the non-operation period,
The first measuring means calculates a predicted time from when the external information processing apparatus is in the non-operating state to the operating state based on the history of the non-operating period, and the non-operating state The wireless communication device according to claim 3, wherein when the elapsed time after becoming equal to or greater than a value obtained by subtracting an offset time from the predicted time, the value of the predetermined time interval is shortened. The history storage means stores an average of the non-operation period as a history of the non-operation period,
The wireless communication apparatus according to claim 6, wherein the first measurement unit uses an average of the non-operation period as the predicted time. A power receiving unit that receives power from the external information processing device when the external information processing device is operating;
An internal power supply for supplying power when the external information processing apparatus is not operating; and
The wireless communication apparatus according to claim 1, wherein the first measurement unit performs measurement immediately after the external information processing apparatus shifts to a non-operation state. When the external information processing apparatus shifts from the non-operating state to the operating state, a third carrier level is measured for a frequency channel in which the latest carrier sense information is available or indicates less than the threshold value. A measuring means,
The carrier determination unit is configured to detect a frequency channel in which a carrier level equal to or higher than a predetermined threshold is detected.
When the latest carrier sense information is available or less than the threshold and the difference between the second carrier level and the third carrier level is less than or equal to a second threshold, it can be used. Decide to be,
When the latest carrier sense information indicates the available or less than the threshold and a difference between the second carrier level and the third carrier level exceeds a second threshold, or the latest When the carrier sense information indicates that it cannot be used, it is determined that it cannot be used.
The wireless communication apparatus according to claim 1. A power receiving unit that receives power from the external information processing apparatus;
The operation detecting means is configured such that the external information processing apparatus is operating when the power receiving unit is supplied with the power, and the external information processing apparatus is not operating when not receiving the power supply. The wireless communication device according to claim 1, wherein the wireless communication device is determined to be in the middle. An operation information receiving unit that receives operation information indicating whether or not the external information processing apparatus is operating;
The wireless communication apparatus according to claim 1, wherein the operation detection unit determines whether or not the external information processing apparatus is operating based on the received operation information. A wireless communication method executed in a wireless communication device connected to an external information processing device,
An operation detecting step for detecting whether or not the external information processing apparatus is operating;
A first measurement step of measuring the first carrier level of each frequency channel one or more times by performing carrier sense for each of the frequency channels when the external information processing apparatus is not operating;
For each measurement of the first carrier level for each frequency channel, a carrier that generates carrier sense information indicating whether each frequency channel is available or indicating the measured first carrier level of each frequency channel A sense information generation step;
Storing the carrier sense information of each frequency channel in a storage device;
A data acquisition step of acquiring transmission data from the external information processing device when the external information processing device is operating;
A second measurement step of measuring a second carrier level of each frequency channel by performing carrier sense on one or more predetermined frequency channels when the transmission data is acquired;
A carrier determination step of determining whether each of the frequency channels is available;
A data transmission step of transmitting the transmission data using the frequency channel determined to be usable by the carrier determination step;
With
The carrier determination step includes
Determining that the frequency channel is available when a second carrier level of the frequency channel is less than a predetermined threshold;
When the second carrier level of the frequency channel is equal to or greater than the predetermined threshold value, it is determined whether or not the frequency channel can be used using carrier sense information corresponding to the frequency channel. Wireless communication method. A communication program executed in a computer connected to an external information processing apparatus,
An operation detecting step for detecting whether or not the external information processing apparatus is operating;
A first measurement step of measuring the first carrier level of each frequency channel one or more times by performing carrier sense for each of the frequency channels when the external information processing apparatus is not operating;
For each measurement of the first carrier level for each frequency channel, a carrier that generates carrier sense information indicating whether each frequency channel is available or indicating the measured first carrier level of each frequency channel A sense information generation step;
Storing the carrier sense information of each frequency channel in a storage device;
A data acquisition step of acquiring transmission data from the external information processing device when the external information processing device is operating;
A second measurement step of measuring a second carrier level of each frequency channel by performing carrier sense on one or more predetermined frequency channels when the transmission data is acquired;
A carrier determination step of determining whether each of the frequency channels is available;
A data transmission step of transmitting the transmission data using the frequency channel determined to be usable by the carrier determination step;
With
The carrier determination step includes
Determining that the frequency channel is available when a second carrier level of the frequency channel is less than a predetermined threshold;
When the second carrier level of the frequency channel is equal to or greater than the predetermined threshold value, it is determined whether or not the frequency channel can be used by using carrier sense information corresponding to the frequency channel. Communication program.

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