JP6533173B2 - Wireless device - Google Patents

Description

  The present invention relates to a wireless device, and more particularly to a device that performs wireless communication with a wireless device using multiple frequency bands.

  Specific low power radios are widely used in data communication and voice communication. The specified low power radio can be used without applying for a license by following the rules for transmission power, frequency band used, transmission time, etc., and is widespread in a wide field of the industry.

  As a communication system using a specific low power radio, for example, there is one in which communication between a computer and a public communication network is performed by a specific low power radio. Patent Documents 1 and 2 describe an alarm device using a specific low power wireless device. In these patent documents, it is described that signals for emergency are transmitted and received in a plurality of frequency bands at the time of emergency such as fire occurrence to improve the reliability of communication.

JP, 2015-14986, A JP, 2015-1914, A

  A plurality of frequency channels are defined in a frequency band used by the specific low power wireless device. In the specific low power wireless device, a control channel is determined separately from the data communication channel for transmitting and receiving data to be transmitted, and the data communication channel is changed using the control channel. In addition, there are also devices that use a control channel to change the communication rate of the data communication channel. However, depending on the communication status in the control channel, the communication conditions such as the data communication channel and the communication rate may not be reliably changed, and the communication status such as the success rate of packet communication may be deteriorated.

  An object of the present invention is to improve communication conditions in wireless communication using a plurality of frequency bands, or to reliably change communication conditions such as frequency channels and communication rates according to the communication conditions.

  The present invention relates to a wireless device performing wireless communication with a wireless device using a plurality of frequency bands, comprising: a redundant communication unit performing the same data communication in a plurality of frequency bands with the wireless device; A determination unit that determines whether or not a predetermined condition is satisfied in a state of data communication using one of the frequency bands, and another frequency band is used when the predetermined condition is not satisfied A control communication unit that changes communication conditions of data communication using the one frequency band by stopping data communication and performing control communication using the other frequency band; and an acknowledge packet transmitted from the wireless device. And an acknowledge receiving unit for receiving an acknowledge packet for the packet transmitted by the wireless device, the determination unit requesting in accordance with the reception status of the acknowledge packet. It is determined whether the predetermined condition is satisfied based on the determined communication goodness, and the redundant communication unit resumes data communication using the other frequency band after the communication condition is changed. It is characterized by

  Desirably, a goodness degree determination unit for obtaining the goodness of communication for each frequency channel included in each of the plurality of frequency bands is provided, wherein the communication condition is a condition related to a frequency channel, and the control communication unit is The frequency channel of the data communication using the one frequency band is changed based on the communication goodness obtained for the channel.

  Preferably, the communication condition is a condition related to at least one of frequency channel, modulation scheme, communication rate, and adoption or rejection of spread spectrum processing.

  Further, according to the present invention, in a wireless device that performs wireless communication with a wireless device using a plurality of frequency bands, a redundant communication unit that performs the same data communication with the wireless device in a plurality of frequency bands; A determination unit that determines whether or not a predetermined condition is satisfied for a state of data communication using the first frequency band and the second frequency band among the plurality of frequency bands, and the predetermined condition is satisfied A control communication unit for stopping data communication using the second frequency band and changing communication conditions of data communication using the first frequency band by control communication using the second frequency band And the control communication unit changes the communication condition to a condition with a higher communication rate, and the redundant communication unit uses the second frequency band after the communication condition has been changed. It is characterized by resuming communication To.

Further, according to the present invention, in a wireless device that performs wireless communication with a wireless device using a plurality of frequency bands, a redundant communication unit that performs the same data communication with the wireless device in a plurality of frequency bands; Among the plurality of frequency bands, a determination unit that determines whether or not a predetermined condition is satisfied for the state of data communication using one frequency band, and another frequency band if the predetermined condition is not satisfied. And a control communication unit that changes communication conditions of data communication using the one frequency band by control communication using the other frequency band, and the communication condition is modulated. scheme, symbol rate, and at least one related conditions of the adoption or rejection of the spread spectrum processing, the redundant communication unit, after the communication condition is changed, to resume communication using the other frequency bands It is characterized in.

  Preferably, the control communication unit determines whether or not data communication is possible after changing the communication condition based on the transmission / reception status of packets with the wireless device; And an iterative processing unit that, when it is determined that data communication is not possible after changing the communication condition, further changes the communication condition and causes the communication check unit to execute processing.

Related art of the present invention, which relates to a radio apparatus for performing radio communication with the radio using a plurality of frequency bands, a first transmission unit for transmitting a plurality of data packets in a predetermined order And a second transmission unit that transmits a data packet that has not been completely transmitted by the first transmission unit among the plurality of data packets, and is to be transmitted first. The one transmission unit and the second transmission unit transmit each data packet using different frequency bands.

  Preferably, an acknowledge packet transmitted from the wireless device, which is an acknowledge reception unit for receiving an acknowledge packet for the packet transmitted by the wireless device, and a data packet for one frequency band among the plurality of frequency bands When the acknowledge packet is not received for a predetermined number of times, when an acknowledge packet for the data packet is received in another one of the plurality of frequency bands, the one frequency band and And a third transmission unit that transmits the next data packet using the one other frequency band.

  Preferably, the first transmitter and the second transmitter transmit each data packet at different communication rates.

  According to the present invention, the communication status in wireless communication using a plurality of frequency bands can be improved, or communication conditions such as frequency channels and communication rates can be reliably changed according to the communication status.

It is a figure showing a communication system concerning an embodiment of the present invention. It is a figure which shows the example of data communication. It is a timing chart of communication condition change processing. FIG. 6 illustrates processing performed between the first wireless device and the second wireless device. It is a timing chart of communication rate up processing. It is a sequence chart of precedence type redundant processing. It is a sequence chart of transmission failure support processing. It is a figure which shows the hardware of a radio | wireless apparatus.

(1) Configuration of Communication System FIG. 1 shows a communication system according to an embodiment of the present invention. The communication system includes a first radio apparatus 10 and a second radio apparatus 12 which perform packet communication. For each wireless device, for example, a frequency band used, transmission / reception power, and the like are designed in accordance with the standard of the specific low power wireless device. Packet communication includes data communication and control communication. In data communication, data packets including communication target data such as voice data, image data, text data, etc. are transmitted from one wireless device to the other wireless device. In the control communication, a control packet for setting communication conditions at the time of data communication is transmitted and received between the first wireless device 10 and the second wireless device 12. The communication conditions include a frequency channel (hereinafter simply referred to as a channel), a communication rate and the like. Then, as a condition for determining the communication rate, there are a modulation scheme, a symbol rate (occupied frequency bandwidth) in each modulation scheme, and the like.

  Data communication between the first radio apparatus 10 and the second radio apparatus 12 is performed by redundant communication using both the A channel included in the A frequency band and the B channel included in the B frequency band. That is, one of the wireless devices transmits data packets including the same communication target data as the A channel radio signal and the B channel radio signal. The other wireless device acquires communication target data from the data packet of the A channel and the B channel for which the data packet has been received first, and does not use the data packet received later.

  When each wireless device is designed in accordance with the specification of a specific low power radio, for example, the specific low power radio such as 400 MHz band, 920 MHz band, 1.2 GHz band, 2.4 GHz band, etc. for A frequency band and B frequency band It is selected from multiple frequency bands defined for the aircraft. Also, as described later, when each wireless device uses three or more multiple frequency bands, these multiple frequency bands are selected from multiple frequency bands defined for a specific low power wireless device. Be

(2) Redundant Processing FIG. 2 shows an example of data communication by a sequence chart. In this figure, the transmission of packets on the A channel is shown as a solid line, and the transmission of packets on the B channel is shown as a dashed line.

  The first radio apparatus 10 transmits a data packet on the A channel (S101), and transmits a data packet on the B channel (S102). In the second wireless device 12, since the data packet is received first on the A channel, the second wireless device 12 acquires communication target data from the data packet (S103). When the time ta has elapsed since the data packet was received on the A channel, the second wireless device 12 receives the data packet on the B channel. When the second wireless device 12 recognizes that the communication target data included in the data packet is the same as the communication target data included in the data packet received earlier, the data received on the B channel is The packet is discarded (S104). Here, discarding of a data packet includes not performing processing on the data packet other than erasing the data packet. In response to the reception of the data packet on the A channel, the second wireless device 12 transmits an acknowledge packet on the A channel (S105). In addition, in response to the reception of the data packet on the B channel, the second radio apparatus 12 transmits an acknowledge packet on the B channel (S106). The first radio apparatus 10 receives each acknowledge packet, and recognizes that the data packet transmitted on each of the A channel and the B channel is received by the second radio apparatus 12.

  Also, as shown in steps S107 and S108, when the first radio apparatus 10 transmits a data packet on the A channel (S107) and transmits a data packet on the B channel (S108), on the A channel It is assumed that the transmitted data packet has not been received by the second wireless device 12 due to the poor communication condition. In this case, the second wireless device 12 acquires communication target data from the data packet received on the B channel (S109). In response to receiving the data packet on the B channel, the second wireless device 12 transmits an acknowledge packet on the B channel (S110). The first radio apparatus 10 receives the acknowledge packet, and recognizes that the data packet transmitted on the B channel is received by the second radio apparatus 12.

  In steps S111 and S112, the first radio apparatus 10 transmits a data packet on the B channel (S111), and transmits a data packet on the A channel (S112). In the second radio apparatus 12, since the data packet is received first on the B channel, the second radio apparatus 12 acquires communication target data from the data packet (S113). When the time tb has elapsed since the data packet was received on the B channel, the second wireless device 12 receives the data packet on the A channel. When the second wireless device 12 recognizes that the communication target data included in the data packet is the same as the communication target data included in the data packet received earlier, the data received on the A channel The packet is discarded (S114). In response to receiving the data packet on the B channel, the second wireless device 12 transmits an acknowledge packet on the B channel (S115). In addition, in response to the reception of the data packet on the A channel, the second wireless device 12 transmits an acknowledge packet on the A channel (S116). The first radio apparatus 10 receives each acknowledge packet, and recognizes that the data packet transmitted on each of the B channel and the A channel is received by the second radio apparatus 12.

  Although the process of transmitting a data packet from the first radio apparatus 10 to the second radio apparatus 12 has been described here, the process of transmitting a data packet from the second radio apparatus 12 to the first radio apparatus 10 is also performed in the same manner. . Also, voice data, image data, text data, etc. are divided into a plurality of data packets and transmitted. Therefore, a plurality of data packets are sequentially transmitted at predetermined time intervals from the wireless device on the transmitting side to the transmitting device on the receiving side.

  According to such redundant communication, data packets including the same communication target data are transmitted from one of the wireless devices on both the A channel and the B channel. The other wireless device acquires communication target data from the previously received data packet. As a result, when the communication status of one channel is not good, the communication target data is transmitted from the one wireless device to the other wireless device by the other channel, and the reliability of the data communication is improved.

(3) Change of Channel When the communication status of one of the A channel and the B channel is not good, the first wireless device 10 and the second wireless device 12 execute the following communication condition change process. That is, the data communication by the other channel whose communication status is good is stopped and control communication is performed instead, and one channel whose communication status is not good is changed to another channel in the same frequency band by the control communication. . For example, when the condition of communication by A channel α1 is not good, the data communication by B channel β1 is stopped, control communication by B channel β1 is performed, and A channel α1 is changed to another A channel α2 in A frequency band. . After the A channel is changed, the first wireless device 10 and the second wireless device 12 resume data communication by the B channel β1 and resume redundant communication.

  Similarly, when the state of communication by the B channel β1 is not good, the first radio apparatus 10 and the second radio apparatus 12 stop data communication by the A channel α1 and perform control communication by the A channel α1, and the B channel β1 To another B channel β 2 in the B frequency band. After the B channel is changed, the first wireless device 10 and the second wireless device 12 resume data communication by the A channel α1 and resume redundant communication.

  Each wireless device determines whether the communication status is good based on the communication status cost. The communication condition cost represents the goodness of communication, and is obtained for each A channel included in the A frequency band and each B channel included in the B frequency band. When each wireless device transmits a data packet and does not receive an acknowledge packet corresponding to the data packet, the communication status cost is increased by a predetermined value to update the communication status cost. When each wireless device receives an acknowledge packet, it reduces the communication status cost by a predetermined value and updates the communication status cost. However, the predetermined value is not increased when the communication condition cost reaches the upper limit value, and is not decreased when the communication condition cost reaches the lower limit value. When the communication condition cost exceeds the upper limit when the communication condition cost is increased by a predetermined value, the communication condition cost is set as the upper limit, and the communication condition cost is decreased by the predetermined value. When the cost becomes smaller than the lower limit value, the communication condition cost is set as the lower limit value. The lower the communication status cost, the better the communication status. Each wireless device determines that the communication status is not good when the communication status cost becomes equal to or higher than a predetermined goodness level determination value.

  In the present embodiment, the initial value of the communication condition cost is 7, and the upper limit value and the lower limit value of the communication condition cost are 15 and 0, respectively. Also, the degree of goodness judgment value is 15. Each wireless device increases the communication condition cost by 2 if it does not receive an acknowledge packet corresponding to the data packet after transmitting the data packet and the communication condition cost has not reached 14. When the communication condition cost is 14 or 15, the communication condition cost is set to the upper limit value 15. On the other hand, after transmitting the data packet, if the acknowledgment packet corresponding to the data packet is received and the communication condition cost has not reached the lower limit value 0, the communication condition cost is reduced by one. As described above, deterioration of the communication status is detected early by setting the value for increasing the communication status cost to be larger than the value for decreasing the communication status cost.

  Each wireless device determines that the communication status is not good when the communication status cost becomes 15 which is the goodness level determination value.

  Also, each time the wireless device receives a data packet or an acknowledge packet, it updates the reception strength average value representing the size of the reception signal. The reception intensity average value is, for example, an average value of reception signals of each packet received for a predetermined number of times retroactively including the last received packet. Further, the reception intensity average value may be an average value of the reception signals of the respective packets received within a time which is a predetermined time before the last reception of the packets. This average value may be a weighted average value that increases the weight as the received signal is newer. The reception intensity average value is determined for each A channel included in the A frequency band and each B channel included in the B frequency band.

  Note that the wireless device that transmits the data packet may execute the following process. For example, the wireless device that transmits the data packet transmits a new data packet the number of times the acknowledge packet has not been received for the past N transmissions of the data packet, including the transmission of the latest data packet. Count every time you do. Then, when the acknowledgment packet is not received over a predetermined number of times out of N times, it is determined that the communication status is not good. Further, the wireless device transmitting the data packet may determine that the communication condition is not good when the magnitude of the received signal of the acknowledge packet becomes equal to or less than a predetermined threshold.

  FIG. 3 shows a timing chart of communication condition change processing. FIG. 3A-1 shows an A channel used by the first wireless device and the second wireless device. FIG. 3 (A-2) shows the communication condition cost in the A channel shown in FIG. 3 (A-1). FIG. 3 (A-3) shows whether the communication performed by the A channel shown in FIG. 3 (A-1) is data communication or control communication.

  Similarly, FIG. 3 (B-1) shows the B channel used by the first wireless device and the second wireless device. The communication condition cost in the B channel shown in FIG. 3 (B-1) is shown in FIG. 3 (B-2). FIG. 3 (B-3) shows whether the communication performed by the B channel shown in FIG. 3 (B-1) is data communication or control communication.

  From time t0 to time t2, the first wireless device sequentially transmits data packets to the second wireless device by redundant communication using the A channel α1 and the B channel β1. That is, the first wireless device sequentially transmits data packets to the second wireless device by the wireless signal of the A channel α1 and the wireless signal of the B channel β1, and performs data communication. The first wireless device transmits data packets including the same communication target data in the A channel α1 and the B channel β1.

  As shown in FIGS. 3 (A-2) and (B-2), when the first wireless device does not receive an acknowledge packet for transmission of a data packet and the communication condition cost has not reached 14 Increases the communication status cost by two. When the communication condition cost is 14 or 15, the communication condition cost is set to the upper limit value 15. On the other hand, when the acknowledgment packet is received for the transmission of the data packet, the communication condition cost is reduced by 1 unless the lower limit value is less than 0.

  The communication condition cost is less than 15 for any of the A channel α1 and the B channel β1 from time t0 to time before time t1. When the communication condition cost of A channel α1 reaches 15 at time t1, the first wireless device stops data communication in B channel β1 and starts control communication while continuing data communication in A channel α1. . Control communication is performed between times t2 and t4 after time t1.

  FIG. 4 shows an example of processing performed between the first wireless device 10 and the second wireless device 12 in control communication. The time axis 10A corresponds to the A channel used in the first radio apparatus 10, and the time axis 10B corresponds to the B channel used in the first radio apparatus 10. The time axis 12A corresponds to the A channel used in the second radio apparatus 12, and the time axis 12B corresponds to the B channel used in the second radio apparatus 12. On each time axis, the channel used at each time is indicated by a code.

  When the control communication on the B channel β1 is started (S201), the first radio apparatus 10 determines to which channel the A channel is to be changed from the A channel α1 used so far (S202). The determination of the channel to change to is made, for example, based on the communication condition cost obtained for each channel. In this case, the condition that the communication condition cost is equal to or less than a predetermined threshold, such as the communication condition cost being equal to or less than the threshold 7, may be set as the condition required for the change destination channel. Furthermore, the channel with the lowest communication status cost may be determined as the channel to be changed. When there are a plurality of channels with the smallest communication status cost, the channel with the largest frequency difference from the current channel may be determined as the channel to be changed. Also, the determination of the change destination channel may be performed based on the reception intensity average value obtained for each channel. In this case, the condition that the reception strength average value is equal to or more than a predetermined threshold may be set as the condition required for the destination channel. In the example shown in FIG. 4, the first radio apparatus 10 determines the A channel α2 as the channel to be changed.

  The first radio apparatus 10 transmits a channel change request packet C (α1 → α2) to the second radio apparatus 12 by the radio signal of the B channel β1 (S203). Here, the code C (α1 → α2) means that the channel change request packet requests the A channel to be changed from α1 to α2.

  The second radio apparatus 12 having received the channel change request packet C (α1 → α2) stops the data communication on the B channel β1 and starts control communication (S204). Then, it is determined whether the communication status of the A channel α2 is good (S205). This determination is performed, for example, based on the communication condition cost obtained for the A channel α2 by the second wireless device 12. In this case, the second wireless device 12 determines that the communication state is good if the communication state cost is equal to or less than a predetermined threshold value, for example, seven. In addition, this determination may be made based on the reception intensity average value obtained for the A channel α2 by the second wireless device 12. In this case, if the reception intensity average value on the A channel α2 is equal to or more than the predetermined threshold value, the second wireless device 12 determines that the communication state is good.

  In the example shown in FIG. 4, the second wireless device 12 determines in step S205 that the communication status of the A channel α2 is not good. Thus, the second wireless device 12 transmits a channel change rejection packet NG to the first wireless device 10 by the wireless signal of the B channel β1 (S206).

  Having received the channel change rejection packet NG, the first radio apparatus 10 again determines the channel of the change destination by the same processing as step S202 (S207). In the example shown in FIG. 4, the first radio apparatus 10 determines the A channel α3 as the channel to be changed.

  The first radio apparatus 10 transmits a channel change request packet C (α1 → α3) to the second radio apparatus 12 by the radio signal of the B channel β1 (S208).

  The second radio apparatus 12 having received the channel change request packet C (α1 → α3) determines whether the communication status of the A channel α3 is good or not by the same processing as step S205 (S209).

  In the example shown in FIG. 4, the second wireless device 12 determines in step S209 that the communication status of the A channel α3 is good. Accordingly, the second wireless device 12 changes the A channel from α1 to α3 (S210), and transmits a channel change acceptance packet OK to the first wireless device 10 by the wireless signal of the B channel β1 (S211).

  Having received the channel change acceptance packet OK, the first radio apparatus 10 changes the A channel from α1 to α3 (S212). After changing the A channel, the first radio apparatus 10 transmits the communication confirmation packet Q1 to the second radio apparatus 12 by the radio signal of the A channel α3 (S213). When the second wireless device 12 receives the communication confirmation packet Q1, the second wireless device 12 transmits the communication response packet R1 to the first wireless device 10 by the wireless signal of the A channel α3 (S214). When receiving the communication response packet R1, the first wireless device 10 ends the control communication by the B channel β1 (S215), and restarts the data communication.

  Here, when the first wireless device 10 does not receive the communication response packet R1, the first wireless device 10 performs the same process as the process exemplified in steps S201 to S212 until the communication response packet R1 is received. A process of changing the A channel is executed together with the two wireless devices 12. When the communication response packet R1 is received after the transmission of the communication confirmation packet Q1, the control communication is ended (S215), and the data communication is restarted.

  Similarly, after changing the A channel, the second wireless device 12 transmits the reachability confirmation packet Q2 to the first wireless device 10 by the wireless signal of the A channel α3 (S216). When the first wireless device 10 receives the communication confirmation packet Q2, the first wireless device 10 transmits a communication response packet R2 to the second wireless device 12 by the wireless signal of the A channel α3 (S217). When the second wireless device 12 receives the communication response packet R2, the second wireless device 12 ends the control communication by the B channel β1 (S218), and restarts the data communication.

  Here, if the second wireless device 12 does not receive the communication response packet R2, the second wireless device 12 performs the process illustrated in steps S201 to S212 until the communication response packet R2 is received. The same processing as that in which the processing of the wireless device 10 and the processing of the second wireless device 12 are replaced is performed. Then, after the transmission of the communication confirmation packet Q2, when the communication response packet R2 is received, the control communication is ended (S218), and the data communication is restarted.

  Returning to FIG. 3, the communication condition change processing will be described. As shown in FIG. 3 (A-1), the first wireless device sets the A channel to α3 at time t3 based on control communication with the second wireless device. At this time, the communication condition cost and the reception intensity average value of the A channel α3 are set to initial values. Then, between time t3 and time t4, the communication confirmation packet is transmitted, and the communication response packet is received. When setting A channel to α3 at time t3, the communication condition cost and the reception intensity average value of A channel α3 may maintain the value immediately before time t3 without using the initial value. The first wireless device ends control communication by the B channel β1 at time t4 and resumes data communication. After time t3, the communication condition of the A channel α3 is good, and the communication condition cost monotonously decreases and reaches 0.

  From time t4 to time t6, the first wireless device sequentially transmits data packets to the second wireless device by redundant communication using the A channel α3 and the B channel β1. That is, the first wireless device sequentially transmits data packets to the second wireless device by the wireless signal of A channel α3 and the wireless signal of B channel β1, and performs data communication. The first wireless device transmits data packets including the same communication target data in the A channel α3 and the B channel β1.

  The communication condition cost is less than 15 for any of the A channel α1 and the B channel β1 from time t4 to time before time t5. When the communication condition cost of B channel β1 reaches 15 at time t5, the first wireless device stops data communication in A channel α3 and starts control communication while continuing data communication in B channel β1. . Control communication is performed between time t6 and time t8 after time t5.

  Through control communication with the A channel α3, the first wireless device sets the B channel to β4 at time t7, and sets the communication condition cost and the reception intensity average value of the B channel β4 to initial values. When setting B channel to β4 at time t7, the communication condition cost and the reception intensity average value of B channel β4 may maintain the value immediately before time t7 without using the initial value. The first wireless device transmits the communication confirmation packet and receives the communication response packet from time t7 to time t8. The first wireless device ends the control communication by the A channel α3 at time t8 and resumes the data communication. After time t7, the communication condition of the B channel β4 is good, and the communication condition cost monotonously decreases and reaches zero.

  In the communication condition change process, when the second wireless device is the transmitting side of the data packet, the second wireless device executes the process executed by the first wireless device in the above description, and the first wireless device performs the process. The second wireless device executes a process to be performed. Also, if the communication conditions of both the A channel and the B channel are not good, the first wireless device and the second wireless device do not execute the communication condition change process.

  As described above, in the communication condition change process, when the communication status by one of the A channel and the B channel is not good, each wireless device stops the data communication by the other channel whose communication status is good and controls instead. Perform communication. Then, one channel whose communication status is not good is changed to another channel in the same frequency band. In the communication condition change process, since the channel whose communication status is not good is changed using the channel whose communication status is good, the channel change is surely performed. This suppresses the decrease in the success rate of packet communication.

(4) Change of Communication Rate In the communication condition change processing described above, one channel whose communication status is not good is changed to another channel within the same frequency band. Instead of such processing, processing may be performed to change the communication rate (the amount of information transmitted per unit time) of one of the channels whose communication status is not good. For example, when the communication condition by one of the A channel and the B channel is not good, the control communication by the channel with the good communication condition is performed, and the communication rate in one channel with the bad communication condition is reduced. When this process tries to change one channel to another channel in the same frequency band, the communication condition cost of all the channels in that frequency band reaches the upper limit value 15, etc. It may be performed when the communication status of all channels in the frequency band is not good.

  The change of the communication rate is performed, for example, by changing the modulation scheme. If the communication condition by one of A channel and B channel is not good, each wireless device performs control communication by a channel with good communication condition, and the modulation scheme in one channel with poor communication condition has a large communication rate Change from small to small.

  As a modulation method, there are a 32 QAM modulation method, a 16 QAM modulation method, a QPSK modulation method, a π / 4 DQPSK modulation method, and the like.

  When the phase angle of the modulation signal is represented by (ωt + φ) and the amplitude is represented by D by the angular frequency ω, time t and initial phase φ, the amplitude D and the initial phase are QAM modulation such as 32 QAM modulation and 16 QAM modulation. A plurality of sets are defined for φ, and a symbol is associated with each set. Here, the symbol means a digital value of one digit or plural digits. Further, in the PSK modulation method such as the QPSK modulation method, a plurality of initial phases φ are defined, and a symbol is associated with each initial phase. In the DPSK modulation method such as the π / 4 DQPSK modulation method, a plurality of time change amounts are defined for the initial phase φ, and a symbol is associated with each time change amount.

  Assuming that the symbol rate representing the number of symbols transmitted per unit time is the same, the communication rate increases in the order of 32 QAM modulation, 16 QAM modulation, and QPSK modulation. Also, assuming that the symbol rates are the same, the communication rates are the same in the QPSK modulation scheme and the π / 4 DQPSK modulation scheme.

  For example, each radio apparatus normally sets the modulation scheme to 16 QAM modulation scheme for both A channel and B channel, changes the modulation scheme of one channel whose communication condition is not good to QPSK modulation scheme, and sets the communication rate Execute the process to make smaller.

  Each wireless device may execute processing to reduce the communication rate by keeping the modulation scheme constant and reducing the symbol rate.

  The occupied frequency bandwidth of the signal transmitting the data packet is determined by the modulation conditions such as the modulation scheme and the symbol rate. For example, increasing the symbol rate widens the occupied frequency bandwidth. Therefore, the number of occupied channels may be changed according to the modulation condition. That is, as modulation conditions that occupy frequencies for a plurality of channels, a plurality of channels continuously arranged on the frequency axis may be used.

  After changing the communication rate, each wireless device that executes control communication may execute processing to restore the communication rate after a predetermined time has elapsed. This makes it possible to cope with temporary deterioration of the communication situation and to prevent the communication rate from being reduced over a long time. When the communication rate is returned to the normal value, each wireless device performs control communication by the control communication channel, and changes the communication rate of the data communication channel to the normal communication rate.

(5) Spread Spectrum Processing In the communication condition change processing, spread spectrum processing may be performed on one of the channels whose communication condition is not good. Spread spectrum processing is processing for multiplying a signal before modulation by a spreading code. At the receiving side, the original signal is reproduced by multiplying the received signal by the spreading code. The signal after the spread spectrum processing has a low signal-to-noise ratio required to improve the communication condition, so that the signal is more resistant to noise and interference. When spread spectrum processing is performed, the occupied frequency bandwidth for transmitting data packets is expanded. Therefore, each wireless device executes processing to increase the number of occupied channels.

(6) Communication Rate Up Process The first wireless device 10 and the second wireless device 12 may execute the communication rate up process when the communication status of both the A channel and the B channel is good. That is, the data communication on one channel may be stopped and control communication may be performed instead, and the control communication may be performed to increase the communication rate of the other channel.

  For example, when the communication condition cost of A channel α1 is equal to or less than a predetermined threshold T1 and the communication condition cost of B channel β1 is equal to or less than a predetermined threshold T2, data communication by B channel β1 is stopped and B channel β1 is stopped. Control communication is performed to increase the communication rate of the A channel α1. In the present embodiment, the threshold T1 is zero and the threshold T2 is seven. After the communication rate of the A channel α1 is changed, the first radio apparatus 10 and the second radio apparatus 12 resume data communication by the B channel β1 and resume redundant communication. The change of the communication rate is performed by changing the modulation scheme, the symbol rate and the like.

  FIG. 5 shows a timing chart of the communication rate up process. FIG. 5A-1 shows the communication rate on A channel α1 used by the first wireless device and the second wireless device. The communication condition cost at the communication rate shown in FIG. 5 (A-1) is shown in FIG. 5 (A-2). FIG. 5 (A-3) shows that the communication performed at the communication rate shown in FIG. 5 (A-1) is data communication.

  Similarly, FIG. 5 (B-1) shows the communication rate on B channel β1 used by the first wireless device and the second wireless device. In FIG. 5 (B-2), the communication condition cost at the communication rate shown in FIG. 5 (B-1) is shown. FIG. 5 (B-3) shows whether the communication performed at the communication rate shown in FIG. 5 (B-1) is data communication or control communication.

  From time t0 to time t2, the first wireless device sequentially transmits data packets to the second wireless device by redundant communication using the A channel α1 and the B channel β1. The communication rate on each channel is the normal communication rate R1.

  As shown in FIG. 5 (A-2) and FIG. 5 (B-2), the first radio apparatus does not receive an acknowledge packet for data packet transmission, and the communication condition cost has reached 14 If not, increase the communication status cost by two. When the communication condition cost is 14 or 15, the communication condition cost is set to the upper limit value 15. On the other hand, when the acknowledgment packet is received for the transmission of the data packet, the communication condition cost is reduced by 1 unless the lower limit value is less than 0.

  From time t0 to time before time t1, the communication condition cost is less than 15 for both A channel α1 and B channel β1, and the communication condition cost for A channel α1 monotonously decreases. At time t1, the communication condition cost of A channel α1 is 0, and the communication condition cost of B channel β1 is 4. Therefore, the condition is established that the communication condition cost of A channel α1 is less than or equal to threshold value T1 = 0 and the communication condition cost of B channel β1 is less than or equal to threshold value T2 = 7. Thereby, the first wireless device stops data communication on the B channel β1 and starts control communication. The first radio apparatus continues the data communication at the communication rate R1 in the A channel α1 also between the time t2 and the time t3 in which the control communication in the B channel β1 is performed.

  Control communication in the communication rate increase process is performed, for example, as follows. The first wireless device transmits a communication rate change request packet to the second wireless device by the B-channel β1 wireless signal. The communication rate change request packet includes information for specifying the communication rate of the change destination, and the like. In the present embodiment, the communication rate change request packet includes information specifying R2 as the communication rate of the change destination. Here, the communication rate R2 is larger than the communication rate R1.

  The second wireless device that has received the communication rate change request packet stops data communication on the B channel β1. Then, the communication rate of the A channel α1 is changed from R1 to R2, and the communication rate change acceptance packet is transmitted to the first wireless device by the wireless signal of the B channel β1. At this time, the second wireless device sets the communication condition cost and the reception intensity average value of the A channel α1 as initial values. The first wireless device having received the communication rate change acceptance packet changes the communication rate of the A channel α1 from R1 to R2. As a result, the communication rate of the A channel used by the first wireless device and the second wireless device at time t3 is changed from R1 to R2. When changing the communication rate, the first wireless device sets the communication condition cost and the reception intensity average value of A channel α1 to initial values.

  After the communication rate of A channel α1 is changed from R1 to R2, as in steps S213, S214, S216 and S217 of FIG. 4, in the time zone from time t3 to time t4, the first wireless device and the second wireless device Between the communication confirmation packet and the communication response packet are transmitted and received. If the first wireless device and the second wireless device do not receive the communication response packet, they return the changed communication rate R2 to the normal communication rate R1.

  In the above description, the second wireless device may execute the process executed by the first wireless device, and the second wireless device may execute the process executed by the first wireless device. Further, among the first wireless device and the second wireless device, the one in which the condition for starting the communication rate increase processing is established first may start the communication rate increase processing earlier.

  In addition to the condition that the communication condition cost of the channel increasing the communication rate is the threshold T1 or less and the communication condition cost of the channel performing the control communication is the threshold T2 or less as the condition of the communication rate increase processing A condition may be added that the reception intensity average value of the channel that performs control communication is equal to or greater than a predetermined threshold value T3.

  In the communication system, three or more types of communication rates may be defined. The communication rate may be increased by one step each time the condition for the communication rate increase processing is satisfied. In addition, the communication rate of the change destination may be maximized, and if communication can not be continued at the changed communication rate, the communication rate may be decreased by one step. The determination as to whether or not communication can be continued at the changed communication rate is made, for example, based on the transmission of the reachability confirmation packet and the reception of the reachability response packet.

(7) Precedence type redundant processing In redundant communication, when the communication rate of A channel and the communication rate of B channel are different, after the acknowledge packet is received by the wireless device in one channel, the other acknowledge packet is received by the wireless device It is received. That is, after transmission on one channel is complete, transmission on the other channel is complete. When sending multiple data packets, if the next data packet is sent after transmission is completed on both channels, the channel with the lower communication rate will limit the overall communication rate by both channels. .

Therefore, in the communication system according to the related art of the present invention, when transmission is completed on one channel, the next data packet is transmitted on one channel without waiting for the completion of transmission on the other channel. The next data packet to be transmitted on one channel is the data packet to be transmitted first among the data packets that have not been transmitted on any channel.

  FIG. 6 shows a sequence chart of such preceding type redundant processing. The time axis 10A corresponds to the A channel α1 used in the first radio apparatus 10, and the time axis 10B corresponds to the B channel β1 used in the first radio apparatus 10. The time axis 12A corresponds to the A channel α1 used in the second radio apparatus 12, and the time axis 12B corresponds to the B channel β1 used in the second radio apparatus 12. The communication rate on A channel α1 is larger than the communication rate on B channel β1.

  The first radio apparatus 10 transmits the data packet D1 on the A channel α1 and the B channel β1. The second radio apparatus 12 that has received the data packet D1 on each channel transmits an acknowledge packet Ack1 on the A channel α1 and the B channel β1.

  The first radio apparatus 10 receives the acknowledge packet Ack1 on the A channel α1. At this time, the first radio apparatus 10 has not received the acknowledge packet Ack1 on the B channel β1. The first radio apparatus 10 does not wait for the reception of the acknowledge packet Ack1 on the B channel β1, and transmits the data packet D2 to be transmitted first among the data packets not completed for transmission on any of the channels A channel α1. Send by

  The second radio apparatus 12 that has received the data packet D2 on the A channel α1 transmits an acknowledge packet Ack2 on the A channel α1.

  The first radio apparatus 10 receives the acknowledge packet Ack2 on the A channel α1. Also at this time, the first radio apparatus 10 has not received the acknowledge packet Ack1 on the B channel β1. The first wireless device does not wait for the reception of the acknowledge packet Ack1 on the A channel α1, and uses the A channel α1 the data packet D3 to be transmitted first among the data packets that have not completed transmission on any of the channels. Send.

  The second radio apparatus 12 that has received the data packet D3 on the A channel α1 transmits an acknowledge packet Ack3 on the A channel α1.

  After the first wireless device 10 transmits the data packet D3 on the A channel α1 and receives the acknowledge packet Ack3 on the A channel α1, the first wireless device 10 transmits the acknowledge packet Ack1 on the B channel β1. To receive. At this time, the first radio apparatus 10 has not received the acknowledge packet Ack3 on the A channel α1. The first radio apparatus 10 does not wait for the reception of the acknowledge packet Ack3 on the A channel α1 and transmits the data packet D3 to be transmitted first among the data packets not completed for transmission on any of the channels on the B channel β1. Send by

  According to such processing, a plurality of data packets are transmitted from one wireless device to the other wireless device without the total communication rate being limited by the channel with the smaller communication rate. In addition, since the next data packet is transmitted after the transmission of the previous data packet is completed, the data packet is reliably transmitted from one wireless device to the other wireless device.

(8) Transmission Failure Support Processing In the preceding redundant processing, transmission failure support processing may be executed when transmission of a data packet has failed for a predetermined number of times in one channel. That is, when an acknowledge packet corresponding to a data packet for which transmission has failed for a predetermined number of times is received later on the other channel, the next data packet is transmitted on both channels. Here, the case where the transmission of the data packet is a failure means the case where an acknowledge packet for the data packet is not received even if a predetermined time has elapsed after the transmission of the data packet. FIG. 7 shows a sequence chart of the transmission failure support process.

  The first radio apparatus 10 transmits the data packet D1 on the A channel α1 and the B channel β1. The second radio apparatus 12 that has received the data packet D1 on each channel transmits an acknowledge packet Ack1 on the A channel α1 and the B channel β1.

  The first radio apparatus 10 receives the acknowledge packet Ack1 on the A channel α1. At this time, the first radio apparatus 10 has not received the acknowledge packet Ack1 on the B channel β1. The first radio apparatus 10 does not wait for the reception of the acknowledge packet Ack1 on the B channel β1, and transmits the data packet D2 to be transmitted first among the data packets not completed for transmission on any of the channels A channel α1. Send by

  FIG. 7 shows an example in which the data packet D2 is not received by the second radio apparatus 12, and the acknowledge packet Ack2 is not transmitted from the second radio apparatus 12 over the A channel α1. The reason why the data packet D2 is not received by the second wireless device 12 is that the communication condition is not good due to noise or interference.

  If the first radio apparatus 10 does not receive the acknowledge packet Ack2 even after a predetermined time has elapsed since transmitting the data packet D2 on the A channel α1, it transmits the data packet D2 on the A channel α1 again.

  FIG. 7 shows an example in which the second wireless device 12 does not receive the second and third transmitted data packets D2, and the second wireless device 12 does not transmit the acknowledge packet Ack2.

In the transmission failure support process in the present technology , when the first wireless device 10 fails to transmit a data packet on one channel three times, an acknowledge packet for the data packet is received on the other channel later. And send the next data packet on both channels. The first radio apparatus 10 does not transmit data packets until then.

  In the example illustrated in FIG. 7, after the third transmission of the data packet D2 fails for the third time, the first wireless device 10 transmits the data packet on the A channel α1 until the acknowledge packet Ack2 is received on the B channel β1. Do not send.

  The first radio apparatus 10 receives the acknowledge packet Ack1 on the B channel β1 after the third transmission of the data packet D2 fails. The first radio apparatus 10 transmits, on the B channel β1, the data packet D2 to be transmitted first among the data packets that have not been transmitted on any channel. When the second radio apparatus 12 receives the data packet D2 on the B channel β1, the second radio apparatus 12 transmits an acknowledge packet Ack2 on the B channel β1.

  When the acknowledge packet Ack2 for the data packet D2 is received on the B channel β1, the first radio apparatus 10 transmits the data packet D3 as the next data packet on the A channel α1 and the B channel β1. In either the A channel α1 or the B channel β1, the data packet D3 is received by the second wireless device 12, and the second wireless device 12 transmits an acknowledge packet Ack3 in each channel. The first radio apparatus 10 receives an acknowledge packet Ack3 on each channel.

  According to such processing, when transmission of the data packet has failed for a predetermined number of times in the channel with the higher communication rate, the data packet is transmitted by the channel with the lower communication rate. In general, the higher the communication rate, the larger the amount of information that can be transmitted per unit time, but the less resistant to noise and interference. The smaller the communication rate, the stronger the resistance to noise and interference, but the smaller the amount of information that can be transmitted per unit time. According to the transmission failure support processing, by compensating for the weakness of one channel with the advantage of the other channel, communication with a high overall communication rate and high resistance to noise and interference is performed.

  In addition, according to such processing, when transmission of a data packet has failed for a predetermined number of times in one channel, when transmission of the data packet is completed by the other channel, both channels are transmitted. Will send the next data packet. That is, until the transmission of the data packet is completed by the other channel, the data channel to be transmitted next to the data packet which failed to be transmitted is not transmitted by one of the channels. Then, the next data packet is transmitted on both channels only when the transmission of the data packet is completed by the other channel. As a result, a plurality of data packets are received in a predetermined order, and processing on the plurality of data packets in the wireless device on the receiving side is simplified.

(9) Overall Configuration of Hardware of Wireless Device (9-1) FIG. 8 shows the hardware of the wireless device 100 used in the communication system. The wireless device 100 is used as the first wireless device 10 and the second wireless device 12 shown in FIG. The wireless device 100 includes a signal processing unit 14 and a wireless unit 16. The radio unit 16 transmits and receives packets by transmitting and receiving radio signals of A channel and B channel. The wireless unit 16 outputs the received packet to the signal processing unit 14, and transmits the packet output from the signal processing unit 14. Also, the wireless unit 16 outputs a reception intensity value indicating the magnitude of the received wireless signal to the signal processing unit 14.

  The signal processing unit 14 includes a redundant communication unit 18, an acknowledge reception unit 20, a goodness degree determination unit 22, a determination unit 24, and a control communication unit 26. The signal processing unit 14 may include a processor that executes arithmetic processing according to a program. In this case, the signal processing unit 14 realizes these components by arithmetic processing. Each component of the signal processing unit 14 may be individually configured by an electronic circuit.

(9-2) Configuration Regarding Redundant Communication The redundant communication unit 18 performs the same data communication in a plurality of frequency bands with another wireless device (wireless device) different from the wireless device 100 via the wireless unit 16. Perform redundant communication. In the communication condition change process and the communication rate increase process, the redundant communication unit 18 stops the redundant communication while the control communication is being performed, and resumes the redundant communication after the control communication is completed.

(9-3) Configuration for Measuring Communication Status The acknowledge receiving unit 20 acquires an acknowledge packet via the wireless unit 16. The degree-of-good determination unit 22 obtains the degree of communication goodness of each channel included in each of the plurality of frequency bands based on the packet acquired via the wireless unit 16. The degree of communication good includes the communication condition cost, the reception intensity average value, and the like.

(9-4) Configuration Regarding Control Communication In the communication condition change process, the determination unit 24 determines a predetermined condition for the state of data communication using one frequency band (A frequency band or B frequency band) among a plurality of frequency bands. It is determined whether or not is satisfied. That is, the determination unit 24 determines whether or not the communication state is good based on the communication goodness degree obtained according to the reception state of the packet.

  Further, in the communication condition changing process, when the predetermined condition is not satisfied, the control communication unit 26 stops data communication using another frequency band (B frequency band or A frequency band) among the plurality of frequency bands, The communication conditions of data communication using one frequency band are changed by control communication using another frequency band. Communication conditions include channel, modulation scheme, communication rate, adoption / disapproval of spread spectrum processing, and the like. The communication rate is changed by changing the modulation scheme, symbol rate (occupied frequency bandwidth) and the like.

  When the communication condition in the communication condition change process is a condition related to a channel, the control communication unit 26 changes the channel of data communication using one frequency band based on the degree of communication goodness obtained for each channel.

  In the communication rate up process, the determination unit 24 uses a first frequency band (A frequency band or B frequency band) and a second frequency band (B frequency band or A frequency band) among a plurality of frequency bands. It is determined whether a predetermined condition is satisfied for the status of data communication.

  Further, in the communication rate up process, when the predetermined condition is satisfied, the control communication unit 26 stops the data communication using the second frequency band, and the first communication communication is performed by the control communication using the second frequency band. Change the communication conditions of data communication using the frequency band of In this case, the control communication unit 26 changes the communication condition of data communication using the first frequency band to a condition with a higher communication rate.

  The control communication unit 26 includes a communication check unit 34 and an iterative processing unit 36. In the communication condition change process and the communication rate increase process, the communication check unit 34 changes the communication condition based on the transmission / reception status of the communication check packet and the communication response packet with another wireless device different from the wireless device 100. It is determined whether later data communication is possible. When it is determined that the data communication is not possible after changing the communication condition, the iterative processing unit 36 further changes the communication condition and causes the communication check unit 34 to execute the processing.

(9-5) Configuration Regarding Precedence Redundant Processing and Transmission Failure Support Processing The redundant communication unit 18 includes the first transmission unit 28, the second transmission unit 30, and the third transmission unit 32, and the above-described preceding redundant processing and transmission failure support Execute the process

  The first transmission unit 28 transmits a plurality of data packets through the wireless unit 16 in a predetermined order. The second transmission unit 30 is a data packet whose transmission by the first transmission unit 28 is not completed among the plurality of data packets, and the data packet to be transmitted first via the wireless unit 16. Send. The first transmitting unit 28 and the second transmitting unit 30 transmit data packets at different communication rates using different frequency bands via the wireless unit 16.

  The third transmission unit 32 transmits the acknowledge packet to the data packet for one frequency band (A frequency band or B frequency band) among the plurality of frequency bands when the acknowledgment packet is not received for a predetermined number of times. When an acknowledge packet for the data packet is received in one frequency band (B frequency band or A frequency band), a data packet to be transmitted next using one frequency band and one other frequency band Are transmitted via the wireless unit 16.

(10) Other Configurations and Processing In the above, the processing in which the first radio apparatus 10 and the second radio apparatus 12 communicate using two frequency bands has been described. Each wireless device may communicate using three or more multiple frequency bands. In this case, the first wireless device 10 and the second wireless device 12 perform redundant communication through channels included in each of the plurality of frequency bands. Each wireless device performs processing in which one frequency band of the plurality of frequency bands is an A frequency band, and the other one of the plurality of frequency bands is a B frequency band.

  Also, in the above, the communication condition change processing for changing any one of the channel, the communication rate, and the like has been described. These communication conditions may be appropriately combined and changed. For example, communication condition change processing may be performed to change both the channel and the communication rate.

  Further, when the first wireless device 10 and the second wireless device 12 first start communication, each wireless device may perform provisional communication at the lowest communication rate. This communication may be communication for transmitting and receiving a training packet for obtaining the communication status cost and the reception intensity average value of each channel.

DESCRIPTION OF SYMBOLS 10 1st radio | wireless apparatus, 12 2nd radio | wireless apparatus, 14 signal processing unit, 16 radio | wireless part, 18 redundant communication part, 20 acknowledgment receiving part, 22 goodness degree determination part, 24 determination part, 26 control communication part, 28 1st transmission Part 30, 30 second transmission part, 32 third transmission part, 34 communication check part, 36 repetition processing part, 100 wireless devices.

Claims (6)

In a wireless device performing wireless communication with a wireless device using a plurality of frequency bands,
A redundant communication unit that performs the same data communication in a plurality of frequency bands with the wireless device;
A determination unit that determines whether a predetermined condition is satisfied for a state of data communication using one of the plurality of frequency bands;
When the predetermined condition is not satisfied, the data communication using the other frequency band is stopped, and the communication condition of the data communication using the one frequency band is changed by the control communication using the other frequency band. A control communication unit,
An acknowledge reception unit that receives an acknowledgment packet for the packet transmitted from the wireless device, the acknowledgment packet being transmitted from the wireless device;
The determination unit determines whether the predetermined condition is satisfied based on the communication goodness degree obtained according to the reception status of the acknowledge packet.
The wireless communication apparatus according to claim 1, wherein the redundant communication unit resumes data communication using the other frequency band after the communication condition is changed. In the wireless device according to claim 1,
And a goodness degree determining unit which obtains the goodness of communication for each frequency channel included in each of the plurality of frequency bands,
The communication condition is a condition regarding a frequency channel,
The control communication unit changes a frequency channel of data communication using the one frequency band based on the degree of communication goodness obtained for each frequency channel. In the wireless device according to claim 1,
The wireless device, wherein the communication condition relates to at least one of a frequency channel, a modulation scheme, a communication rate, and adoption or rejection of spread spectrum processing. In a wireless device performing wireless communication with a wireless device using a plurality of frequency bands,
A redundant communication unit that performs the same data communication in a plurality of frequency bands with the wireless device;
A determination unit that determines whether a predetermined condition is satisfied for a state of data communication using a first frequency band and a second frequency band among the plurality of frequency bands;
When the predetermined condition is satisfied, data communication using the second frequency band is stopped, and communication of data communication using the first frequency band is performed by control communication using the second frequency band. And a control communication unit that changes the condition;
The control communication unit changes the communication condition to a condition that the communication rate is high,
The wireless communication apparatus characterized in that the redundant communication unit resumes data communication using the second frequency band after the communication condition is changed. In a wireless device performing wireless communication with a wireless device using a plurality of frequency bands,
A redundant communication unit that performs the same data communication in a plurality of frequency bands with the wireless device;
A determination unit that determines whether a predetermined condition is satisfied for a state of data communication using one of the plurality of frequency bands;
When the predetermined condition is not satisfied, the data communication using the other frequency band is stopped, and the communication condition of the data communication using the one frequency band is changed by the control communication using the other frequency band. And a control communication unit,
The communication condition is a condition relating to at least one of modulation scheme, symbol rate, and adoption or rejection of spread spectrum processing,
The wireless communication apparatus characterized in that the redundant communication unit resumes communication using the other frequency band after the communication condition is changed. The wireless device according to any one of claims 1 to 5.
The control communication unit
A continuity check unit that determines whether or not data communication is possible after changing the communication condition based on the transmission / reception status of packets with the wireless device;
An iterative processing unit that, when it is determined that data communication is not possible after changing the communication condition, further changes the communication condition and causes the communication check unit to execute processing;
A wireless device comprising:

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