JP4069125B2 - Transmission method, transmission apparatus, and transmission / reception system - Google Patents

Description

The present invention relates to a data signal between communication devices is bidirectional transmission, transmission method, transmit device, and to a transmitting and receiving system.

  Recently, a transmission / reception system in which one or a plurality of transmission apparatuses and one or a plurality of reception apparatuses are connected via a transmission line to receive a data signal bidirectionally is often used. The state of the transmission line used in such bidirectional reception only needs to be kept stable and constant, but it is generally known that the transmission line state actually changes with time. . For example, even in a bidirectional transmission / reception system using a cable television network using a coaxial cable, the state of the transmission path changes with time.

  Due to such a change in the transmission path state, when the communication apparatus is powered down and restarted, transmission may not be possible even if transmission is attempted with the transmission power used for the previous communication.

  In order to solve this problem, there has been proposed a communication device that performs power adjustment when the communication device is activated (see, for example, Patent Document 1).

  Hereinafter, embodiments of a transmission power determination method for determining transmission power between communication apparatuses (for example, a master station and a slave station) that bidirectionally transmit data signals will be described with reference to the drawings.

  FIG. 9 is a configuration diagram of a communication system that bidirectionally transmits a conventional data signal.

  In the communication system of FIG. 9, the master station 51 and the slave station 52 have a downlink transmission path 53 for transmitting a signal from the master station 51 to the slave station 52 and a signal for transmitting a signal from the slave station 52 to the master station 51. They are connected by an upstream transmission path 54.

  The master station 51 detects an uplink signal receiver 61 that receives a signal transmitted from the slave station 52 using the uplink transmission path 54, and detects a transmission power value of the slave station 52 from the input signal received by the uplink signal receiver 61. And an uplink reference transmission power instruction unit 63 that indicates a reference value of the transmission power value of the slave station 52. Further, with respect to the reference value of the transmission power value of the slave station 52 indicated by the uplink reference transmission power instruction unit 63, the transmission power value of the slave station 52 detected by the uplink transmission power detection unit 62 is within a predetermined range. An uplink transmission power determination unit 64 that requests the slave station 52 to reset the transmission power value is provided. Further, a downlink signal transmission unit 65 that notifies the transmission power value information requested by the uplink transmission power determination unit 64 to the slave station 52 using the downlink transmission path 53 is provided.

  The slave station 52 is notified to the slave station 52 from the downlink signal receiving unit 71 that receives a signal transmitted from the master station 51 using the downlink transmission path 53 and the input signal received by the downlink signal receiving unit 71. A transmission power storage unit 72 that extracts transmission power value information and stores the transmission power value, and an uplink transmission power instruction unit 73 that instructs the uplink transmission power value from the transmission power value information stored in the transmission power storage unit 72. It has. Also, an uplink signal transmission unit 74 that transmits a signal to the uplink transmission path 54 with a transmission power value based on an instruction indicated by the uplink transmission power instruction unit 73, and a transmission power setting unit 75 that sets a transmission power value to the master station 51. And an initial transmission power storage unit 76 for storing the initial value of the transmission power value to the master station 51.

  Next, the transmission power determination operation between the master station 51 and the slave station 52 will be described.

  An operation of starting communication from a state where communication between the slave station 52 and the master station 51 is not connected will be described. Here, a case where the slave station 52 is restarted after being turned off will be described.

  First, in the slave station 52, the uplink transmission power instruction unit 73 sets the transmission power value of the previous communication stored in the transmission power storage unit 72 in the transmission power setting unit 75 and starts communication with the parent station 51. Let However, when the communication has not been performed, that is, when communication with the master station 51 is performed for the first time, the uplink transmission power instruction unit 73 uses the transmission power value stored in the initial transmission power storage unit 76 as the transmission power. Set in the setting unit 75.

  When there is no response from the master station 51 via the downlink transmission path 53 and no transmission power value information is notified, the slave station 52 causes the uplink transmission power instruction unit 73 to increase the uplink transmission power value and the transmission power setting unit 75. And communication with the master station 51 is resumed. Then, until the transmission power value is notified from the master station 51 through the downlink transmission path 53, the slave station 52 repeats transmission of signals while increasing the transmission power value in the same manner.

  On the other hand, the master station 51 receives a signal transmitted from the slave station 52 using the uplink transmission path 54 by the uplink signal receiving unit 61. From the input signal received by the upstream signal receiving unit 61, the upstream transmission power detection unit 62 detects the transmission power value from the slave station 52.

  Then, the uplink transmission power determination unit 64 compares the transmission power value detected by the uplink transmission power detection unit 62 with the reference value of the transmission power value of the slave station 52 indicated by the uplink reference transmission power value instruction unit 63, The transmission power value required of the slave station 52 is determined in order to make the transmission power value of the slave station 52 a predetermined transmission power value. Then, the uplink transmission power determination unit 64 notifies the slave station 52 of information on the transmission power value requested from the determined slave station 52 from the downlink signal transmission unit 65 using the downlink transmission path 53. Here, the uplink transmission power determination unit 64 may notify the transmission power value to be set by the slave station 52 as the transmission power value information, or the transmission power value detected by the uplink transmission power detection unit 62 The slave station 52 may be notified of the difference from the reference value.

  Then, the slave station 52 receives the signal transmitted from the master station 51 through the downlink transmission path 53 by the downlink signal receiving unit 71. The transmission power storage unit 72 extracts the information of the transmission power value notified to the slave station 52 from the signal received by the downlink signal reception unit 71 and stores it. The uplink transmission power instruction unit 73 sets the transmission power value stored in the transmission power storage unit 72 in the transmission power setting unit 75. The uplink signal transmission unit 74 transmits a signal to the uplink transmission path 54 with the transmission power value set by the uplink transmission power instruction unit 73 in the transmission power setting unit 75.

In this way, after the transmission power value requested from the parent station 51 is notified through the downlink transmission path 53, the slave station 52 sets the transmission power with the information of the notified latest transmission power value, and transmits the transmission power. I do. In this way, the transmission power between the slave station 52 and the master station 51 is determined.
JP-A-9-186633

  However, in the conventional transmission power determination method as described above, when connection is impossible with the previous transmission power value at the time of restart, the time from the start of the communication device to the time when data communication becomes possible increases, and the efficiency Data communication could not be performed.

  That is, when the transmission path state between the communication apparatuses is different from that before the restart, the slave station 52 transmits the signal while increasing the transmission power value until the transmission power value requested from the master station 51 is notified. In order to repeat, the time from the start of the slave station 52 until the data communication with the master station 51 becomes possible increases.

  Even in the conventional transmission power determination method, by increasing the transmission power at the time of transmission from the slave station 52 for the first time after restarting, from the start of the slave station 52 until data communication with the master station 51 becomes possible However, in this case, useless transmission power is generated, and the transmission power more than necessary may interfere with other devices.

The present invention solves the above-described conventional problems, and enables data communication with a receiving apparatus without using wasted power when connection with the previous transmission power value is impossible at the time of reconnection. can shorten the time until, and an object thereof is to provide a method, transmit device and the receive system transmission.

In order to solve the above-described problem, a first aspect of the present invention is a transmission method between communication apparatuses that are bidirectionally transmitted.
A transmission success / failure detection step for detecting whether the transmission is successful or unsuccessful on the transmission side;
When transmission fails, refer to the transmission power value selection table in which a plurality of power values are grouped step by step for each predetermined width in order of magnitude, and from the group to which the failed transmission power value belongs. A next transmission step in which a minimum power value among power values belonging to a group of power values that are larger by one stage is set to the next transmission power value and transmitted;
When the transmission is successful, a transmission power value determination step for determining the successful transmission power value as a transmission power value for communicating with the receiving side ;
A reception power width notifying step of sending information related to a fluctuation range of received power from the reception side to the transmission side;
And a power value table width adjustment step of appropriately adjusting the predetermined width of the transmission power value selection table based on the information on the fluctuation range .

The second aspect of the present invention
The transmission power value at the time of starting the connection with the reception side includes a connection start transmission step in which transmission is performed using the transmission power value that has been successfully transmitted immediately before or the transmission power initial value that is set in advance. The transmission method according to the first aspect of the present invention is further provided.

The third aspect of the present invention
When the connection start transmission step transmits using the transmission power initial value,
The transmission power value determination step is the transmission method according to the second aspect of the present invention, wherein the transmission power initial value is updated with a transmission power value determined for communication with the receiving side.

The fourth aspect of the present invention is
The transmission power value determined in the transmission power value determination step is set as a temporary transmission power value, which is larger than the largest transmission power value among transmission failures after the start of connection with the receiving side, and the temporary transmission power In order to communicate with the receiving side the smallest transmission power value that has been successfully transmitted after the start of connection with the receiving side after setting and transmitting one or more transmission power values within the range of the value The transmission method according to the second aspect of the present invention further includes a transmission power adjustment step for re-determining the transmission power value.

The fifth aspect of the present invention provides
The power value table width adjustment step is the transmission method according to the first aspect of the present invention, wherein the predetermined width is adjusted so as to be an interval smaller than a difference between the minimum value and the maximum value of the received power.

The sixth aspect of the present invention provides
The transmission success / failure detection step includes:
Information on the transmission rate measured on the reception side, a transmission rate notification step to send from the reception side to the transmission side,
In the transmission method according to the first aspect of the present invention , the transmission method includes a transmission success / failure determination step in which the transmission side determines that the transmission is not successful when the transmission rate is lower than a predetermined reference transmission rate. .

The seventh aspect of the present invention
A transmitting device that performs bidirectional transmission with a receiving device,
A transmission success / failure detection means for detecting whether the transmission has succeeded or failed;
A transmission power value selection table in which a plurality of power values are grouped step by step for each predetermined width in order of magnitude;
When the transmission fails, the transmission power value selection table is referred to, and the minimum power value of the power values belonging to the power value group larger by one step than the group to which the failed transmission power value belongs is determined. A transmission power value setting means for determining a transmission power value for communication with the receiving device as it is, if the transmission is successful, if the transmission is successful.
Transmitting means for transmitting at the transmission power value set by the transmission power value setting means ;
A transmission apparatus comprising: a power value table width adjustment unit that appropriately adjusts the predetermined width of the transmission power value selection table based on information about a fluctuation range of reception power transmitted from the reception apparatus. It is.

In addition, the eighth aspect of the present invention
The transmission power value setting means sets a transmission power value at which transmission has been successful immediately before or a preset transmission power initial value as a transmission power value when starting connection with the receiving device. , A transmission device according to a seventh aspect of the present invention;

The ninth aspect of the present invention provides
When the transmission power value setting means sets the transmission power initial value to the transmission power value when starting connection with the receiving device,
The transmission success / failure detection means is the transmission apparatus according to the eighth aspect of the present invention, wherein the transmission power initial value is updated with a transmission power value determined for communication with the reception apparatus.

The tenth aspect of the present invention is
The transmission power value determined by the transmission power value setting means is used as a temporary transmission power value, which is larger than the largest transmission power value among transmission failures after the start of connection with the receiving apparatus, and the temporary transmission power. After setting one or more transmission power values within the range of the value and causing the transmission means to transmit, the smallest transmission power value that has been successfully transmitted after the start of connection with the receiving device is received. The transmission apparatus according to the eighth aspect of the present invention further includes transmission power adjustment means for re-determining a transmission power value for communication with the apparatus.

The eleventh aspect of the present invention is
The power value table width adjusting means is the transmitting apparatus according to the seventh aspect of the present invention, wherein the predetermined width is adjusted so as to be an interval smaller than a difference between the minimum value and the maximum value of the received power.

The twelfth aspect of the present invention is
The transmission success / failure detection means includes:
From the information sent from the receiving device, receiving side transmission rate acquisition means for acquiring information on the transmission rate measured by the receiving device;
When the transmission rate is lower than a predetermined reference transmission rate , the transmission device according to the seventh aspect of the present invention includes transmission success / failure determination means for determining that the transmission has not been successful.

The thirteenth aspect of the present invention is
A receiving device;
A transmission success / failure detection means for detecting whether the transmission has succeeded or failed;
A transmission power value selection table in which a plurality of power values are grouped step by step for each predetermined width in order of magnitude;
When the transmission fails, the transmission power value selection table is referred to, and the minimum power value of the power values belonging to the power value group larger by one step than the group to which the failed transmission power value belongs is determined. A transmission power value setting means for determining a transmission power value for communication with the receiving device as it is, if the transmission is successful, if the transmission is successful.
Transmitting means for transmitting at the transmission power value set by the transmission power value setting means;
A transmission apparatus comprising: a power value table width adjustment unit that appropriately adjusts the predetermined width of the transmission power value selection table based on information on a fluctuation range of reception power transmitted from the reception apparatus ;
A transmission / reception system including a transmission path connected to the reception device and the transmission device for bidirectional communication.

The fourteenth aspect of the present invention is
The receiving device is:
Transmission rate measuring means for measuring the transmission rate to be received, and transmission rate transmission means for transmitting information on the transmission rate ,
The transmission success / failure detection means of the transmission device comprises:
A receiving-side transmission rate acquisition means for acquiring information on a transmission rate measured by the receiving device from information sent from the receiving device, and the transmission rate is lower than a predetermined reference transmission rate the, the transmission that Yusuke transmission success determining means for determining that no successful, and a second 13 transceiver system of the present invention.

The fifteenth aspect of the present invention provides
Of the transmission method of the first aspect of the present invention;
The transmission success / failure detection step of detecting whether the transmission is successful or unsuccessful at the transmission side,
When the transmission fails, the transmission power value selection table is referred to, and the minimum power value of the power values belonging to the power value group larger by one step than the group to which the failed transmission power value belongs is determined. , The next transmission step of setting and transmitting to the next transmission power value,
When the transmission is successful, the transmission power value determining step for determining the successful transmission power value as a transmission power value for communicating with the receiving side,
A reception power width notifying step of sending information on the fluctuation range of the received power from the reception side to the transmission side; and
A program for causing a computer to function in order to execute the power value table width adjustment step of appropriately adjusting the predetermined width of the transmission power value selection table based on information on the fluctuation range .

The 16th aspect of the present invention is
A fifteenth program-recorded recording medium that can be used by a computer.

According to the present invention, when connection is impossible with the previous transmission power value at the time of reconnection, a transmission method that can shorten the time until data communication with the receiving device can be performed without using wasteful power , transmit device, and can provide a reception system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a configuration diagram of a communication system for bidirectional transmission of data signals according to Embodiment 1 of the present invention.

  In the communication system of the first embodiment, the communication device 11 and the communication device 12 are connected by a transmission path 13. The transmission path 13 is a transmission path connected by wire such as a cable television network. The communication device 11 and the communication device 12 have the same configuration.

  FIG. 2 is a configuration diagram of the communication device 11 and the communication device 12 according to the first embodiment.

  Each of the communication device 11 and the communication device 12 includes an initial transmission power storage unit 21 that stores an initial value of a transmission power value used when starting a connection with a connection destination communication device. In addition, an initial transmission instruction unit 22 that instructs to transmit data with the transmission power value stored in the initial transmission power storage unit 21 is provided. In addition, a connection threshold value setting unit 23 that sets a threshold value for performing a connection determination with a communication apparatus as a connection destination is provided.

  In addition, a transmission power table unit 24 having a transmission power value table for determining a transmission power value to be used at the time of retransmission after connection failure with the connection destination communication device is provided. In addition, a retransmission instruction unit 25 that instructs to retransmit data with the transmission power value determined from the transmission power value table is provided. In addition, a data transmission unit 26 that transmits data with a transmission power value instructed by the initial transmission instruction unit 22 or the retransmission instruction unit 25 is provided.

  In addition, a data receiving unit 27 that receives data from a communication device that is a connection destination and a transmission rate measuring unit 28 that measures a transmission rate from the data received by the data receiving unit 27 are provided. In addition, a transmission rate information generation unit 29 that generates transmission rate information for notifying the communication apparatus of the connection destination from the transmission rate measured by the transmission rate measurement unit 28 is provided.

  In addition, a transmission rate information extraction unit 210 that extracts transmission rate information notified from the communication device of the connection destination from the data received by the data reception unit 27 is provided. Whether the connection with the communication device at the connection destination has succeeded or failed with the transmission rate information extracted by the transmission rate information extraction unit 210 and the threshold for performing the connection determination set by the connection threshold setting unit 23. A connection determination unit 211 for determining the connection.

  In addition, a reception power measurement unit 212 that measures the power of data received from the connection destination communication device during connection with the connection destination communication device is provided. The reception power range storage unit 213 holds the lower limit value and the upper limit value of the reception power measured by the reception power measurement unit 212. In addition, a reception power range information generation unit 214 is provided that generates reception power range information for notifying the communication device of the connection destination from the reception power range stored in the reception power range storage unit 213.

  In addition, a reception power range information extraction unit 215 is provided that extracts reception power range information notified from a connection destination communication device from data received by the data reception unit 27. In addition, a transmission power table updating unit 216 that updates the transmission power value of the transmission power value table based on the reception power range information extracted by the reception power range information extraction unit 215 is provided.

  The connection determination unit 211 corresponds to an example of a transmission success / failure detection unit and a transmission success / failure determination unit according to the present invention. Further, the retransmission instruction unit 25 corresponds to an example of a transmission power value setting unit of the present invention. The data transmission unit 26 corresponds to an example of a transmission unit of the present invention. Further, the transmission rate information extraction unit 210 corresponds to an example of a receiving side transmission rate acquisition unit of the present invention. In addition, the initial value of the transmission power value stored in the initial transmission power storage unit 21 corresponds to an example of a preset transmission power initial value of the present invention.

  Next, a transmission method for determining transmission power between communication devices in the communication system according to the first embodiment will be described with reference to FIGS.

  Here, as an example, an operation when the communication device 11 is turned on and communication with the communication device 12 is started will be described. In this case, the communication device 11 corresponds to an example of the transmission device of the present invention, and the communication device 12 corresponds to an example of the reception device of the present invention.

  FIG. 3 shows a processing flow of the communication apparatus 11 after the communication apparatus 11 is powered on. FIG. 4 illustrates an example of a transmission power value table included in the transmission power table unit 24 of the communication apparatus 11 according to the first embodiment.

  In the first embodiment, the range of transmission power values that can be set by the communication apparatus 11 is set to Power = 0 to 100, and the initial value of the transmission power value is set to Power = 30. The numerical values shown in the transmission power value table of FIG. 4 indicate the values of Power.

  The transmission power value table in FIG. 4 corresponds to an example of a transmission power value selection table according to the present invention. In the transmission power value table of FIG. 4, the group divided into three as “failed transmission power values” is grouped in stages according to the predetermined width in order of the power values of the present invention. This is an example of a group. And the range of the electric power value which shows the range of each group corresponds to an example of the predetermined width of the present invention.

  When the connection source communication device 11 is turned on, first, the initial transmission instruction unit 22 starts connection with the connection destination communication device 12 stored in the initial transmission power storage unit 21. The data transmission unit 26 is instructed to transmit data with the initial transmission power value to be used (Power = 30). The data transmission unit 26 transmits data to the transmission line 13 with the instructed transmission power value (S301). Here, the transmission is performed using the initial value of the transmission power value stored in the initial transmission power storage unit 21, but the transmission power value that has been successfully transmitted to the communication device 12 immediately before, that is, You may make it start transmission to the communication apparatus 12 using the transmission power value used by transmission before the power supply of the communication apparatus 11 is turned off.

  Then, it is determined whether or not there is a response from the connection destination communication device 12 (S302). When there is no response (for example, when there is no response exceeding the response notification time), the retransmission instruction unit 25 The transmission power value table (FIG. 4) of the transmission power table unit 24 is referred to determine a transmission power value for retransmission, and the data transmission unit 26 is instructed to retransmit the data with the transmission power value. To do. In the transmission power value table shown in FIG. 4, since the transmission power value when the connection fails with Power = 30 is Power = 40, the retransmission instruction unit 25 performs data transmission so that the data is retransmitted with Power = 40. The unit 26 is instructed. Then, the data transmission unit 26 transmits data to the transmission line 13 with the instructed transmission power value (S303).

  In this case, the group of “0 or more and less than 40” of the failed transmission power value in FIG. 4 to which Power = 30 belongs is an example of the group to which the failed transmission power value belongs according to the present invention. The group of “40 or more and less than 70” corresponds to an example of a group having a power value that is larger by one step according to the present invention.

  Then, the connection source communication device 11 determines whether or not there is a response from the connection destination communication device 12 (S304), and increases the transmission power value until a response is made from the communication device 12 while the data is being transmitted. The retransmission (the processes of S303 and S304) is repeated. If there is no response even with a transmission power value of Power = 40, referring to the transmission power value table of FIG. 4, next, retransmission is performed with Power = 70. Here, as an example, the following description will be given assuming that there is a response with a transmission power value of Power = 40.

  On the other hand, the communication device 12 of the connection destination receives the data from the communication device 11 transmitted through the transmission path 13 by the data receiving unit 27. Then, the transmission rate measuring unit 28 measures the transmission rate of the data received from the connection source communication device 11 from the received data received by the data receiving unit 27. Then, the transmission rate information generation unit 29 generates transmission rate information from the transmission rate measured by the transmission rate measurement unit 28, and transmits the transmission rate information from the data transmission unit 26 to the connection source communication device 11 through the transmission path 13. Send it.

  The process of transmitting the transmission rate information from the communication device 12 to the communication device 11 corresponds to an example of the transmission rate notification step of the present invention. The transmission rate information transmitted at this time corresponds to an example of information regarding the transmission rate measured on the receiving side according to the present invention.

  If there is a response from the communication device 12 in the process of S304 in the communication device 11 of the connection source, the data receiving unit 27 next receives the transmission rate information transmitted from the communication device 12 through the transmission path 13. To do. Then, the transmission rate information extraction unit 210 extracts transmission rate information from the data received by the data reception unit 27 (S305).

  Next, the connection determination unit 211 compares the transmission rate information extracted by the transmission rate information extraction unit 210 with the threshold for performing the connection determination set by the connection threshold setting unit 23, and the communication device 12 Is determined (S306). The threshold for performing connection determination set by the connection threshold setting unit 23 corresponds to an example of a predetermined reference transmission rate according to the present invention.

  For example, assuming that the threshold for determining connection is “100 Mbps or higher”, the connection determination unit 211 determines “successful connection” when the transmission speed information is 100 Mbps or higher, and the transmission speed information is less than 100 Mbps. It is determined that “connection failed”.

  Here, it is assumed that the transmission rate information received from the communication device 12 when the transmission is performed with the transmission power value Power = 40 that is a response from the communication device 12 in the process of S304 is 80 Mbps. That is, since the transmission rate information in this case is less than 100 Mbps, the connection determination unit 211 determines that the connection with the communication device 12 has failed.

  If it is determined that the connection is unsuccessful, the process returns to the process of S303, and the retransmission instruction unit 25 refers to the transmission power value table of the transmission power table unit 24 to determine the transmission power value for transmission, and the transmission The data transmission unit 26 is instructed to retransmit the data with the power value. Here, since the transmission power value when it is determined that the connection has failed in the process of S306 is Power = 40, the retransmission instruction unit 25 refers to the transmission power value table and retransmits next with Power = 70. The data transmission unit 26 is instructed as follows.

  As illustrated in FIG. 3, the connection-source communication device 11 repeats data retransmission (the processes in S303 to S306) until the connection determination by the connection determination unit 211 is successful.

  Then, if the transmission rate information received from the communication device 12 at the time of transmission with Power = 70 is 120 Mbps, the threshold value is 100 Mbps or more, so that the connection determination unit 211 has successfully connected to the communication device 12. Judgment is made and Power = 70 is determined as a transmission power value for communicating with the communication apparatus 12, and thereafter, the communication apparatus 11 communicates with the communication apparatus 12 with a transmission power value of Power = 70. Then, the connection determination unit 211 uses the initial value (here, Power = 30) of the transmission power value stored in the initial transmission power storage unit 21 as the transmission power value (here, Power = 70) for which the connection determination is successful. ).

  Note that the processing of S301 corresponds to an example of a connection start transmission step of the present invention. The processing of S302 and S304 is an example of the transmission success / failure detection step of the present invention. The process of S303 is an example of the next transmission step of the present invention. The process of S306 corresponds to an example of a transmission success / failure determination step and a transmission power value determination step of the present invention.

  As described above, the transmission success / failure determination method of the present invention is characterized in that a difference in transmission rate caused by a modulation scheme or the like that changes according to transmission power is used for connection determination. The threshold for performing connection determination may be changed according to data to be transmitted / received. For example, this threshold value may be increased in the case of streaming data that requires a large amount of data and real-time characteristics, and the threshold value may be decreased if the data amount is small.

  Further, the reception power measurement unit 212 of the connection destination communication device 12 measures the reception power value of the data received from the communication device 11 while connected to the communication device 11, and the measurement is performed in the reception power range storage unit 213. Stores the lower and upper limits of the received power value. Then, the reception power range information generation unit 214 generates reception power range information from the reception power range (lower limit value and upper limit value) stored in the reception power range storage unit 213, and transmits the received power range information from the data transmission unit 26 through the transmission path 13. The received power range information is transmitted to the communication device 11.

  The process of measuring the received power value of the received data and transmitting the received power range information to the communication device 11 corresponds to an example of the received power width notification step of the present invention. In addition, the received power range information transmitted to the communication device 11 at this time corresponds to an example of information related to the fluctuation range of the received power according to the present invention.

  In the connection source communication device 11, the data receiving unit 27 receives the received power range information transmitted from the communication device 12 through the transmission path 13. Then, the received power range information extracting unit 215 extracts received power range information from the data received by the data receiving unit 27. Based on the received power range information, the transmission power table update unit 216 updates the power value grouping interval of the transmission power value table included in the transmission power table unit 24.

  Here, the transmission power table updating unit 216 updates the transmission power value table so that the power value grouping interval is narrower than the range of the reception power range information.

  FIG. 5 shows an example of the transmission power value table after updating the transmission power value table of FIG. The interval of grouping the power values in the transmission power value table of FIG. 4 before the update is 30 or 40. For example, when the upper limit value of the received power range information is Power = 80 and the lower limit value is Power = 50, the power value grouping interval in the transmission power value table is within this range (80−50 = 30) is updated so as to be in a narrower range (for example, 20). The transmission power value table in FIG. 5 is an example in which the grouping interval of power values in the transmission power value table is changed to 20.

  The process of updating the transmission power value table based on the received power range information is an example of the power value table width adjustment step of the present invention.

  Thereafter, when reconnection is performed, the transmission power is determined using the updated transmission power value table of FIG.

  In the transmission method of the present invention, when transmission fails, the “next transmission” defined stepwise according to the size of the “failed transmission power value” group range in the transmission power value table of FIG. `` Power value '' is set to the transmission power value at the time of retransmission, but if the range of the group of `` failed transmission power value '' is too large, it will be transmitted with more transmission power than necessary at the time of retransmission There is also. The fluctuation range of the received power of the data received on the receiving device side is the same even if the magnitude of the received power value changes if the transmission path state is the same. Therefore, if the range of the “failed transmission power value” group in FIG. 4 is set to an appropriate range according to the fluctuation range of the reception power, it is appropriate as the transmission power value at the time of retransmission (not larger than necessary). ) The transmission power value can be selected. In the transmission power value table update process described above, the range of the “failed transmission power value” group is updated to an appropriate range according to the fluctuation range of the reception power.

  In the description of the second embodiment, the example in which the range of the “failed transmission power value” group in FIG. 4 is reduced has been described. However, when the fluctuation range of the reception power is large, conversely in FIG. Updating is performed so that the range of the “failed transmission power value” group becomes larger.

  After the above processing, when the communication apparatus 11 is turned off and then on again, the transmission power value in the initial transmission power storage unit 21 is updated to the transmission power value that has been successfully connected. Therefore, there is a high probability that the communication device 12 can be connected at the first transmission (at the time of processing in S301). If the connection fails in the first transmission, retransmission is performed using the transmission power values specified in stages in the “next transmission power value” column of the transmission power value table of FIG. Therefore, connection with the communication apparatus 12 is possible in a short time. Further, since the interval of the “next transmission power value” defined in FIG. 5 is defined based on the fluctuation range of the reception power of the communication device 12, there is a concern that a transmission power value larger than necessary may be set. Absent.

  The process for determining the transmission power value shown in the flow of FIG. 3 is performed at the time of reconnection of the communication system, but the process for updating the transmission power value table according to the fluctuation range of the reception power is appropriately performed. It may be performed during connection. For example, if update processing of the transmission power value table is performed at regular intervals, the transmission power value table based on the transmission path state in the near time will be provided at the next reconnection of the communication system. Can be used. When the time is close, there is a high possibility that the amount of change in the transmission path state is small, and a transmission power value based on the transmission path state close to the transmission path state at the time of reconnection can be set.

  As described above, by using the transmission / reception system of the present invention, when connection is impossible with the previous transmission power value at the time of restart, the transmission power value at the time of connection failure and the transmission power at the time of connection failure By making a reconnection request by setting the transmission power value at the time of reconnection request with the value selection table, the power adjustment time is shortened, enabling data communication in a short time from the start of the communication device, Data communication with high transmission efficiency between communication devices can be realized.

  In addition, by measuring the change in the power level during communication, the transmission power value at the time of the reconnection request is determined in response to the change in the transmission path state between the communication devices, and communication is performed between the communication devices. Can do.

  In the first embodiment, only the connection determination at the communication device 11 is described, but the connection determination may be performed by both the communication device 11 and the communication device 12.

  Further, the communication apparatus 11 generates transmission power information from the transmission power value determined by the method described in the first embodiment, transmits the transmission power information to the communication apparatus 12, and transmits the transmission power information received by the communication apparatus 12 to the transmission power. It is good as a value.

  Further, transmission power information is generated from the transmission power value determined by the method described in the first embodiment in the communication apparatus 11, transmitted to the communication apparatus 12, and the transmission power information received by the communication apparatus 12 is transmitted. The transmission power may be determined by the method described in the first embodiment as the initial value of the transmission power value for starting connection with a value.

(Embodiment 2)
FIG. 6 is a configuration diagram of a communication system for bidirectional transmission of data signals according to Embodiment 2 of the present invention.

  In the communication system of the second embodiment, the communication device 45 and the communication device 46 are connected by the transmission path 13. The transmission path 13 is a transmission path connected by wire such as a cable television network. The communication device 45 and the communication device 46 have the same configuration.

  FIG. 7 is a configuration diagram of the communication device 45 and the communication device 46 according to the second embodiment. The same components as those of the communication devices 11 and 12 of the first embodiment shown in FIG. Hereinafter, components different from those of the first embodiment will be described.

  Communication device 45 and communication device 46 according to the second embodiment, in addition to the configurations of communication devices 11 and 12 according to the first embodiment, transmit power that holds the upper and lower limits of transmittable transmission power values, respectively. A range storage unit 41 is provided. Also, when the connection with the communication device at the connection destination fails, the lower limit value of the transmittable transmission power value held in the transmission power range storage unit 41 is updated to the transmission power value when the connection fails. The transmission power range updater 42 is provided. Further, the minimum transmission power that can be connected is determined in the range between the transmission power value that is successfully connected and the lower limit value of the transmittable transmission power value that is stored in the transmission power range storage unit 41. A minimum transmission power determination unit 43 is provided.

  Similarly to the connection determination unit 211 of the first embodiment, the connection determination unit 44 uses the threshold for performing the connection determination set by the connection threshold setting unit 23 to determine the connection destination based on the transmission speed information. Although it is determined whether the connection with the communication device is successful or unsuccessful, the processing content is different from that of the connection determination unit 211 of the first embodiment. The connection determination unit 44 corresponds to an example of a transmission success / failure detection unit and a transmission success / failure determination unit according to the present invention.

  Next, a transmission method for determining transmission power between communication devices in the communication system according to the second embodiment will be described with reference to FIGS. 4 and 6 to 8.

  Here, as an example, an operation when the communication device 45 is turned on and communication with the communication device 46 is started will be described. In this case, the communication device 45 corresponds to an example of the transmission device of the present invention, and the communication device 46 corresponds to an example of the reception device of the present invention.

  FIG. 8 shows a processing flow of the communication device 45 after the communication device 45 is turned on.

  In the second embodiment, for example, the initial value of the transmission power value is set to Power = 30, the upper limit value of the transmittable transmission power value is set to Power = 100, and the lower limit value is set to Power = 0. Similarly to the first embodiment, the transmission power value table shown in FIG. 4 is used as the transmission power value table.

  When the connection source communication device 45 is turned on, first, the initial transmission instruction unit 22 starts connection with the connection destination communication device 46 stored in the initial transmission power storage unit 21. The data transmission unit 26 is instructed to transmit data with the initial transmission power value to be used (Power = 30). The data transmission unit 26 transmits data to the transmission line 13 with the instructed transmission power value (S801).

  Then, it is determined whether or not there is a response from the connection destination communication device 46 (S802). When there is no response (for example, when there is no response exceeding the response notification time), the retransmission instruction unit 25 determines whether there is a response. The transmission power value table (FIG. 4) of the transmission power table unit 24 is referred to determine a transmission power value for retransmission, and the data transmission unit 26 is instructed to retransmit the data with the transmission power value. To do. In the transmission power value table shown in FIG. 4, since the transmission power value when the connection fails with Power = 30 is Power = 40, the retransmission instruction unit 25 performs data transmission so that the data is retransmitted with Power = 40. The unit 26 is instructed. Then, the data transmission unit 26 transmits data to the transmission line 13 with the instructed transmission power value (S803).

  Then, the connection source communication device 45 determines whether there is a response from the connection destination communication device 46 (S804), and increases the transmission power value until a response is made from the communication device 46. The retransmission (the processes of S803 and S804) is repeated. As in the first embodiment, the following description will be given here assuming that there is a response with a transmission power value of Power = 40 as an example.

  On the other hand, the communication device 46 of the connection destination receives the data from the communication device 45 transmitted through the transmission path 13 by the data receiving unit 27. Then, the transmission rate measuring unit 28 measures the transmission rate of the data received from the connection source communication device 45 from the received data received by the data receiving unit 27. The transmission rate information generation unit 29 generates transmission rate information from the transmission rate measured by the transmission rate measurement unit 28, and the transmission rate information is transmitted from the data transmission unit 26 to the connection source communication device 45 through the transmission path 13. Send it.

  If there is a response from the communication device 12 in the processing of S804 in the connection source communication device 45, then the data receiving unit 27 receives the transmission rate information transmitted from the communication device 46 through the transmission path 13. To do. Then, the transmission rate information extraction unit 210 extracts transmission rate information from the data received by the data reception unit 27 (S805).

  Next, as in the first embodiment, the connection determination unit 44 determines the transmission rate information extracted by the transmission rate information extraction unit 210 and the threshold for performing the connection determination set by the connection threshold setting unit 23. In comparison, the connection with the communication device 46 is determined (S806).

  If it is determined that the connection has failed, the transmission power range update unit 42 updates the lower limit value stored in the transmission power range storage unit 41 to the transmission power value that has failed to be connected (S810). Here, since the transmission power value when it is determined that the connection has failed in the processing of S806 is Power = 40, specifically, the lower limit value stored in the transmission power range storage unit 41 is changed from Power = 0 to Power. = 40.

  Then, after updating the lower limit value stored in the transmission power range storage unit 41, the process returns to S803, and the retransmission instruction unit 25 refers to the transmission power value table (FIG. 4) of the transmission power table unit 24. The transmission power value at the time of retransmission is determined, and the data transmission unit 26 is instructed to retransmit the data with the transmission power value. Here, since the transmission power value when it is determined that the connection has failed in the processing of S806 is Power = 40, the retransmission instruction unit 25 refers to the transmission power value table and retransmits next with Power = 70. The data transmission unit 26 is instructed as follows.

  Here, it is assumed that the transmission rate information received from the communication device 12 when transmitting with Power = 70 is 120 Mbps. Then, in step S806, the connection determination unit 44 determines that the connection with the communication device 12 has been successful, and then performs step S807.

  In the processing of S807, the minimum transmission power determination unit 43 determines the communication device 46 from a range that is smaller than the smallest transmission power value that has been successfully connected and larger than the lower limit value stored in the transmission power range storage unit 41. Select the transmission power value for confirming the connection. Here, since the transmission power value that has been successfully connected is Power = 70, and the lower limit value stored in the transmission power range storage unit 41 is Power = 40, the minimum transmission power determination unit 43 determines the range between these values. It is assumed that Power = 55 is selected as the transmission power value for confirming the connection with the communication device 46. Then, the minimum transmission power determination unit 43 instructs the data transmission unit 26 to retransmit the data with the selected transmission power value (Power = 55). Note that the smallest transmission power value (Power = 70 in this case) successfully used for connection, which is used when selecting the transmission power value, is an example of the provisional transmission power value of the present invention.

  Then, it is determined whether or not there is a response from the connection destination communication device 46 (S808). If there is a response, the process returns to S805. In the process of S806, if it is determined that the connection with the communication device 46 is successful with the transmission power value of Power = 55, the smallest transmission power value that has been successfully connected is set to Power = 55, and the process of S807 is performed. Will be performed. In this case, the minimum transmission power determination unit 43 sets a transmission power value (for example, Power = 47) for performing next connection confirmation with the communication device 46 from a range smaller than Power = 55 and larger than Power = 40. Select and repeat the process according to the flow shown in FIG.

  On the other hand, if there is no response from the communication device 46 in the processing of S808, the minimum transmission power determination unit 43 connects the smallest transmission power value that has been successfully connected so far to the communication with the communication device 46. The transmission power value to be determined is set in the data transmission unit 26. At the same time, the minimum transmission power determination unit 43 updates the initial value of the transmission power stored in the initial transmission power storage unit 21 to the transmission power value determined as the transmission power value connected to the communication with the communication device 46. (S809).

  Here, if it is determined that the connection is successful in the process of S806 when Power = 55, and there is no response in the process of S808 when Power = 47, the transmission power value that has been successfully connected so far. Since Power = 70 and 55, the transmission power value connected to the communication with the communication device 46 is determined as Power = 55, and the initial value of the transmission power stored in the initial transmission power storage unit 21 is also Power = It will be updated to 55. Further, similarly, a transmission power value that can be connected within a range that is larger than Power = 40 and smaller than Power = 55 is obtained, and is determined as a transmission power value that is connected to communication with the communication device 46. Also good.

  Also, in the processing of S808, if there is no response when Power = 55, the transmission power value that has been successfully connected so far is only Power = 70, so the transmission power value that is connected to the communication with the communication device 46. Is determined to be Power = 70, and the initial value of the transmission power stored in the initial transmission power storage unit 21 is also updated to Power = 70. In a similar manner, a transmission power value that can be connected within a range larger than Power = 55 and smaller than Power = 70 is obtained, and is determined as a transmission power value that is connected to communication with the communication device 46. Also good.

  The process of S801 corresponds to an example of a connection start transmission step of the present invention. Further, the processing of S802 and S804 corresponds to an example of a transmission success / failure detection step of the present invention. Further, the processing of S803 corresponds to an example of the next transmission step of the present invention. Further, the process of S806 corresponds to an example of a transmission success / failure determination step of the present invention. Further, the processing of S807 and S808 corresponds to an example of the transmission power adjustment step of the present invention. Further, the processing of S809 corresponds to an example of a transmission power value determination step of the present invention.

  As described in the second embodiment, the transmission method of the present invention sets the previous transmission power value to the lower limit value when the communication device cannot be connected with the previous transmission power value when the communication apparatus is restarted. In addition, after the connection is established, the transmission power is adjusted up to the transmission power value at which the transmission power can be connected with the minimum transmission power between the upper limit value of the transmission power value and the set lower limit value.

  By adjusting the transmission power in this way, the transmission power can be reduced, and data communication with high transmission efficiency between communication devices can be realized. In addition to reducing power consumption, when there is another device sharing the transmission medium, the influence on the device can be reduced.

  In each embodiment, as an example of reconnection, the case where the power of the transmission source communication devices 11 and 45 is turned on has been described. However, the present invention can be applied to other reconnected states. For example, the present invention can also be applied to a case where a transmission source communication device is reset or a case where a link is connected again after a logical link between communication devices is temporarily disconnected.

  The program of the present invention is a program for causing a computer to execute all or some of the operations of the transmission success / failure detection step, the next transmission step, and the transmission power value determination step of the transmission method of the present invention described above. It is a program that operates in cooperation with a computer.

  In addition, the recording medium of the present invention is a program for causing a computer to execute all or some of the operations of the transmission success / failure detection step, the next transmission step, and the transmission power value determination step of the transmission method of the present invention described above. Is a recording medium that is readable by a computer and that is used in cooperation with the computer.

  The “partial steps” of the present invention mean one or several steps out of the plurality of steps.

  The program of the present invention is a program for causing a computer to execute the operation of both or one of the transmission rate notification step and the transmission success / failure determination step of the transmission success / failure determination method of the present invention described above. It is a program that operates in cooperation with.

  The recording medium of the present invention is a recording in which a program for causing a computer to execute the operation of both or one of the transmission rate notification step and the transmission success / failure determination step of the transmission success / failure determination method of the present invention described above is recorded. It is a recording medium that can be read by a computer and that can be used in cooperation with the computer.

  Further, one usage form of the program of the present invention may be an aspect in which the program is recorded on a computer-readable recording medium and operates in cooperation with the computer.

  Further, the recording medium includes a ROM and the like.

  The computer of the present invention described above is not limited to pure hardware such as a CPU, and may include firmware, an OS, and peripheral devices.

  As described above, the configuration of the present invention may be realized by software or hardware.

Transmission method according to the present invention, transmit device, and transmitting and receiving system, when the reconnection can not be connected in the previous transmission power value, without using unnecessary power, allows data communication with a receiving device It is useful as a transmission method, a transmission success / failure determination method, a transmission device, a transmission / reception system, and the like in which a data signal is bidirectionally transmitted between communication devices.

1 is a configuration diagram of a communication system for bidirectional transmission of data signals according to Embodiment 1 of the present invention. Configuration diagram of communication apparatus according to Embodiment 1 of the present invention The figure which shows the processing flow at the time of power ON of the communication apparatus of the connection source of Embodiment 1 of this invention The figure which shows an example of the transmission power value table of Embodiment 1 and Embodiment 2 of this invention The figure which shows an example of the transmission power value table after the update of Embodiment 1 of this invention. Configuration diagram of a communication system for bidirectional transmission of data signals according to the second embodiment of the present invention Configuration diagram of communication apparatus according to Embodiment 2 of the present invention The figure which shows the processing flow at the time of power ON of the communication apparatus of the connection origin of Embodiment 2 of this invention Configuration diagram of a communication system for bidirectional transmission of conventional data signals

Explanation of symbols

11, 12, 45, 46 Communication device 13 Transmission path 21, 76 Initial transmission power storage unit 22 Initial transmission instruction unit 23 Connection threshold setting unit 24 Transmission power table unit 25 Retransmission instruction unit 26 Data transmission unit 27 Data reception unit 28 Transmission Speed measurement unit 29 Transmission rate information generation unit 210 Transmission rate information extraction unit 211, 44 Connection determination unit 212 Reception power measurement unit 213 Reception power range storage unit 214 Reception power range information generation unit 215 Reception power range information extraction unit 216 Transmission power table Update unit 41 Transmission power range storage unit 42 Transmission power range update unit 43 Minimum transmission power determination unit 51 Master station 52 Child station 53 Down transmission channel 54 Up transmission channel 61 Up signal reception unit 62 Up transmission power detection unit 63 Up reference transmission power Indication unit 64 Uplink transmission power determination unit 65 Downlink signal transmission unit 71 Downlink signal reception unit 7 Transmission power storage unit 73 uplink transmission power instruction unit 74 uplink signal transmission unit 75 transmission power setting unit 76 the initial transmit power storing unit

Claims (16)

A transmission method between two-way communication devices,
A transmission success / failure detection step for detecting whether the transmission is successful or unsuccessful on the transmission side;
When transmission fails, refer to the transmission power value selection table in which a plurality of power values are grouped step by step for each predetermined width in order of magnitude, and from the group to which the failed transmission power value belongs. A next transmission step in which a minimum power value among power values belonging to a group of power values that are larger by one stage is set to the next transmission power value and transmitted;
When the transmission is successful, a transmission power value determination step for determining the successful transmission power value as a transmission power value for communicating with the receiving side ;
A reception power width notifying step of sending information related to a fluctuation range of received power from the reception side to the transmission side;
And a power value table width adjusting step for appropriately adjusting the predetermined width of the transmission power value selection table based on the information on the fluctuation range .   The transmission power value at the time of starting the connection with the reception side includes a connection start transmission step in which transmission is performed using the transmission power value that has been successfully transmitted immediately before or the transmission power initial value that is set in advance. The transmission method according to claim 1, further comprising: When the connection start transmission step transmits using the transmission power initial value,
The transmission method according to claim 2, wherein the transmission power value determination step updates the transmission power initial value with a transmission power value determined for communication with the receiving side.   The transmission power value determined in the transmission power value determination step is set as a temporary transmission power value, which is larger than the largest transmission power value among transmission failures after the start of connection with the receiving side, and the temporary transmission power In order to communicate with the receiving side the smallest transmission power value that has been successfully transmitted after the start of connection with the receiving side after setting and transmitting one or more transmission power values within the range of the value The transmission method according to claim 2, further comprising a transmission power adjustment step of re-determining the transmission power value of the transmission power. 2. The transmission method according to claim 1 , wherein the power value table width adjustment step adjusts the predetermined width to be an interval smaller than a difference between a minimum value and a maximum value of the reception power. The transmission success / failure detection step includes:
Information on the transmission rate measured on the reception side, a transmission rate notification step to send from the reception side to the transmission side,
2. The transmission method according to claim 1, further comprising: a transmission success / failure determination step of determining on the transmission side that the transmission has not been successful when the transmission rate is lower than a predetermined reference transmission rate . A transmitting device that performs bidirectional transmission with a receiving device,
A transmission success / failure detection means for detecting whether the transmission has succeeded or failed;
A transmission power value selection table in which a plurality of power values are grouped step by step for each predetermined width in order of magnitude;
When the transmission fails, the transmission power value selection table is referred to, and the minimum power value of the power values belonging to the power value group larger by one step than the group to which the failed transmission power value belongs is determined. A transmission power value setting means for determining a transmission power value for communication with the receiving device as it is, if the transmission is successful, if the transmission is successful.
Transmitting means for transmitting at the transmission power value set by the transmission power value setting means ;
A transmission apparatus comprising: a power value table width adjustment unit that appropriately adjusts the predetermined width of the transmission power value selection table based on information about a fluctuation range of reception power transmitted from the reception apparatus. . The transmission power value setting means sets a transmission power value at which transmission has been successful immediately before or a preset transmission power initial value as a transmission power value when starting connection with the receiving device. The transmission device according to claim 7 . When the transmission power value setting means sets the transmission power initial value to the transmission power value when starting connection with the receiving device,
The transmission apparatus according to claim 8 , wherein the transmission success / failure detection unit updates the transmission power initial value with a transmission power value determined to communicate with the reception apparatus. The transmission power value determined by the transmission power value setting means is used as a temporary transmission power value, which is larger than the largest transmission power value among transmission failures after the start of connection with the receiving apparatus, and the temporary transmission power. After setting one or more transmission power values within the range of the value and causing the transmission means to transmit, the smallest transmission power value that has been successfully transmitted after the start of connection with the receiving device is received. The transmission apparatus according to claim 8 , further comprising transmission power adjustment means for re-determining a transmission power value for communication with the apparatus. The transmission apparatus according to claim 7 , wherein the power value table width adjusting unit adjusts the predetermined width so as to be an interval smaller than a difference between a minimum value and a maximum value of the reception power. The transmission success / failure detection means includes:
From the information sent from the receiving device, receiving side transmission rate acquisition means for acquiring information on the transmission rate measured by the receiving device;
The transmission device according to claim 7 , further comprising: a transmission success / failure determination unit that determines that the transmission has not been successful when the transmission rate is lower than a predetermined reference transmission rate. A receiving device;
A transmission success / failure detection means for detecting whether the transmission has succeeded or failed;
A transmission power value selection table in which a plurality of power values are grouped step by step for each predetermined width in order of magnitude;
When the transmission fails, the transmission power value selection table is referred to, and the minimum power value of the power values belonging to the power value group larger by one step than the group to which the failed transmission power value belongs is determined. A transmission power value setting means for determining a transmission power value for communication with the receiving device as it is, if the transmission is successful, if the transmission is successful.
Transmitting means for transmitting at the transmission power value set by the transmission power value setting means;
A transmission apparatus comprising: a power value table width adjustment unit that appropriately adjusts the predetermined width of the transmission power value selection table based on information on a fluctuation range of reception power transmitted from the reception apparatus ;
A transmission / reception system comprising: a transmission path connected to the reception device and the transmission device for bidirectional communication. The receiving device is:
Transmission rate measuring means for measuring the transmission rate to be received, and transmission rate transmission means for transmitting information on the transmission rate ,
The transmission success / failure detection means of the transmission device comprises:
A receiving-side transmission rate acquisition means for acquiring information on a transmission rate measured by the receiving device from information sent from the receiving device, and the transmission rate is lower than a predetermined reference transmission rate the, that Yusuke transmission success determining means determines that the transmission was not successful, the transmission and reception system according to claim 13. The transmission method according to claim 1.
The transmission success / failure detection step of detecting whether the transmission is successful or unsuccessful at the transmission side,
When the transmission fails, the transmission power value selection table is referred to, and the minimum power value of the power values belonging to the power value group larger by one step than the group to which the failed transmission power value belongs is determined. , The next transmission step of setting and transmitting to the next transmission power value,
When the transmission is successful, the transmission power value determining step for determining the successful transmission power value as a transmission power value for communicating with the receiving side,
A reception power width notifying step of sending information on the fluctuation range of the received power from the reception side to the transmission side; and
A program for causing a computer to function in order to execute the power value table width adjustment step of appropriately adjusting the predetermined width of the transmission power value selection table based on the information on the fluctuation range . A recording medium on which the program according to claim 15 is recorded, the recording medium being usable by a computer.

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