JP4584161B2 - Wireless terminals that make up a multi-hop network - Google Patents

Description

  The present invention relates to a wireless terminal constituting a multi-hop network that relays information by relaying a plurality of wireless terminals.

  In a conventional multi-hop network, when a relay route is constructed, the link quality between terminals participating in the relay is measured and a relay route is selected (for example, see Patent Document 1). In addition, a method for solving radio wave interference by measuring reception intensity and adjusting transmission power has been proposed (see, for example, Patent Document 2).

JP 2005-33557 A JP 2003-258697 A

  As described above, the conventional multi-hop network selects the relay route using the link quality of communication. This is based on the premise that a relay wireless terminal has already been installed and a relay route has been established. When constructing a new wireless system, design a line for wireless relay, and determine whether communication is possible between individual wireless terminals placed on the relay path, by transmitting radio waves from one of the wireless terminals, and the other wireless terminal Measures are taken such as measuring the received radio wave intensity in the vicinity of the mobile terminal or confirming the link quality using a function held in the wireless terminal by attempting communication between the wireless terminals. In the installation of a relay station by checking the link quality between individual wireless terminals manually as described above, there is a problem that the installation cost increases as the number of wireless terminals increases.

  The present invention has been made to solve the above-described problems, and provides a radio terminal constituting a multi-hop network that can easily obtain link quality between radio terminals constituting the multi-hop network. For the purpose.

  A wireless terminal constituting a multi-hop network according to the present invention is a wireless terminal constituting a multi-hop network that relays information by relaying a plurality of wireless terminals, and receives a radio wave and demodulates it to receive information A received radio wave intensity measuring unit that measures the intensity of the radio wave received by the receiving unit, a communication frame interpreting unit for decoding and analyzing the received communication frame, and a communication frame analyzed by the communication frame interpreting unit A communication frame generation unit that generates a communication frame to be transmitted according to information; and a transmission unit that modulates the communication frame generated by the communication frame generation unit and radiates the communication frame as a radio wave, the communication frame being processed by a wireless terminal A command field for storing, an issuer field for storing the number of the wireless terminal that instructed the received radio field strength measurement, The total number of stages for storing the destination field for storing the number of the wireless terminal to which the communication frame is sent, the source field for storing the number of the wireless terminal for transmitting the communication frame, and the number of communication stages required for measuring the received radio field strength Stores the field, the current stage number field for storing the number of communication stages where the received radio field strength measurement was performed, the communication route storage field for storing the number list of wireless terminals that measure the received radio field intensity, and the measurement result of the received radio field intensity The received radio field strength storage field, and the communication frame generator is configured to receive the received radio field when the command field of the received communication frame is interpreted as a received radio field intensity measurement command by the communication frame interpreter. The received radio field intensity measured by the intensity measuring unit is extracted and the radio field intensity storing unit field of the communication frame is extracted. Stored in the field specified by the current stage number in the field, add 1 to the current stage field value, store it in the current stage field, compare the current stage field value with the total stage field value, When the total number of stages in the field is greater than or equal to the current stage number in the current stage number field, the ID specified in the current stage number field in the communication route storage field is extracted and stored in the destination field, and the own ID is stored in the source field. The communication frame generated in step 1 is sent to the transmission unit, and when the command field of the received communication frame is interpreted as a received radio wave strength measurement reply command by the communication frame interpretation unit, the value of the current stage number field is decremented by 1. Is stored in the current stage number field, and it is determined whether or not the value of the current stage number field is greater than 0. The ID specified in the current stage number field in the communication route storage unit is extracted and stored in the destination field, and the communication frame generated by storing the own ID in the transmission source field is sent to the transmission unit, and the determination As a result, when the value of the current stage number field is 0, the value of the destination field is compared with the value of the issuer field, and if the value is not the same, the value of the issuer field is stored in the destination field and the own ID is stored in the source field The communication frame generated by storing in the transmission field is sent to the transmission unit, the value of the destination field is compared with the value of the issuer field, and if the same, the reception radio field strength measurement is completed and the result is displayed. .

  According to the present invention, since the communication route is specified and the received radio wave intensity between the wireless terminals is measured, stored, and transmitted, the received radio wave intensity between the individual radio terminals can be remotely measured. The link quality between the wireless terminals constituting the multi-hop network can be easily obtained.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an internal configuration of a radio terminal constituting the multihop network according to Embodiment 1 of the present invention. The wireless terminal shown in FIG. 1 is for receiving and demodulating a radio wave and receiving and demodulating the radio terminal to receive information and receiving the receiver 1 and measuring and storing the intensity of the radio wave received by the receiver 1. A reception radio wave intensity measurement unit 2, a communication frame interpretation unit 3 for decoding and analyzing the received communication frame, and a communication frame for generating a transmission frame according to the information of the communication frame analyzed by the communication frame interpretation unit 3 A communication frame generation unit 4, a transmission unit 5 having an antenna or the like for modulating the communication frame and emitting it as a radio wave, and a communication success monitoring unit 6 having a timer or the like for confirming that the issued command is received at the destination And.

  FIG. 2 is a diagram showing the structure of a communication frame used for measuring the received radio wave strength between the wireless terminals constituting the multi-hop network of the present invention. The communication frame shown in FIG. 2 includes a command field 20 that stores processing executed by the wireless terminal, an issuer field 21 that stores the number of the wireless terminal that has instructed measurement of received radio wave intensity, and a wireless terminal that is the destination of the communication frame. , A destination field 22 for storing the number of the wireless terminal that transmits the communication frame, a total field number field 24 for storing the number of communication stages required for measuring the received radio wave intensity, and the received radio wave The current stage number field 25 for storing the number of communication stages for which the intensity measurement has been performed, the communication route storage field 26 for storing the number list of wireless terminals for which the received radio field intensity is measured, and the received radio wave for storing the measurement result of the received radio field intensity And an intensity storage field 27.

  Next, as in the example shown in FIG. 3, an operation for measuring the received radio wave intensity along the route of wireless terminal A → wireless terminal B → wireless terminal C → wireless terminal D → wireless terminal E will be described. First, the startup process of the received radio wave intensity measurement performed by the wireless terminal A will be described. In order to measure the received radio wave intensity along the route of the radio terminal B → the radio terminal C → the radio terminal D → the radio terminal E, the radio terminal A uses the communication frame generation unit 4 in the command field 20 to “receive radio wave intensity measurement” “Command”, “A” in the issuer field 21, “B” in the destination field 22, “4” in the total stage number field 24, “1” in the current stage number field 25, and the communication route storage field 26. ID1 261 is “B”, ID2 262 is “C”, ID3 263 is “D”, ID4 264 is “E”, received signal strength storage field 27 strength 1 271 to strength 4 274 is an initial value (For example, “0”) is stored. The communication frame generation unit 4 sends the communication frame generated in this way to the transmission unit 5 to perform wireless communication.

  Next, the operation of measuring the received radio wave intensity will be described with reference to the flowchart shown in FIG. The receiving unit 1 of the wireless terminal B receives wireless communication from the wireless terminal A, and the received radio wave intensity measuring unit 2 measures and stores the received radio wave intensity of the received radio wave. At the same time, the communication frame interpretation unit 3 interprets the communication frame (step 1). Since the interpretation result is a received radio wave intensity measurement command, step 2 is “YES”.

  Next, the communication frame generation unit 4 starts processing of a received radio wave intensity measurement command. First, the communication frame generating unit 4 extracts the received radio wave intensity of the radio wave received from the received radio wave intensity measuring unit 2 and is designated by the current stage number field 25 (value is “1”) in the received radio wave intensity storage unit field 27. Store in the field of intensity 1 271 (step 3). Then, the value of the current stage number field 25 is incremented by 1 and stored in the current stage number field 25 (step 4).

  Next, the current stage number field 25 and the total stage number field 24 are compared (step 5). Since “2” is stored in the current stage number field 25 and “4” is stored in the total stage number field 24, the comparison result in step 5 is “YES”. Next, the communication destination “C” is stored from the field of ID2 262 designated by the current stage number field 25 (value is “2”) in the communication route storage section field 26 (step 6). Next, the own ID “B” is stored in the transmission source field 23 (step 7). Thereafter, the generated communication frame is sent to the transmission unit 5 to perform wireless communication (step 8). Next, the communication success monitoring unit 6 is started (for example, timer timing is started) (step 9). Since the communication to the wireless terminal C is successful, the comparison result in step 10 is “YES”, and the measurement processing of the received radio wave intensity at the wireless terminal B is completed. Successful communication from the wireless terminal B to the wireless terminal C can be performed by response communication to the command.

  In wireless terminal C and wireless terminal D, since the current stage number is “3” to “4” with respect to the total stage number “4”, the comparison result in step 5 is “YES”. Accordingly, processing similar to that performed by the wireless terminal B is performed. In the wireless terminal E, the same processing as that of the wireless terminal B is performed from step 1 to step 4. The comparison result of step 5 is “NO” because the current stage number is “5” with respect to the total stage number “4”, and the reply communication is started (step 12).

  Next, activation of reply communication performed by the communication frame generation unit 4 of the wireless terminal E will be described. First, the communication frame sent from the wireless terminal D for measuring the received radio wave intensity is set as the base of the communication frame. Next, a “reception radio wave intensity measurement reply command” is set in the command field 20. Next, the current stage number field 25 is subtracted by 2 and set in the current stage number field 25. At this time, the value of the current stage number field 25 is “3”. Next, the data (value is “D”) extracted from the field ID 3 specified in the current stage number field 25 in the communication route storage field 26 is in the destination field 22, and the own ID “E” is in the transmission source field 23. Store. Next, the generated communication frame is sent to the transmission unit 5 to perform wireless communication.

  Next, a reply communication propagation operation will be described with reference to the flowchart shown in FIG. The receiving unit 1 of the wireless terminal D receives wireless communication from the wireless terminal E, and then the communication frame interpreting unit 3 interprets the communication frame (step 21). Since the interpretation result is a received radio wave intensity measurement reply command, step 22 is “YES”. Next, the communication frame generation unit 4 processes the received radio wave intensity measurement response command. The value of the current stage number field 25 is decremented by 1 and stored in the current stage number field 25 (step 23). Next, the value of the current stage number field 25 is evaluated. Since the value in the current stage number field 25 is “2”, the comparison result in step 24 is “YES”. Next, the communication destination “C” is stored from the field of ID2 262 designated in the current stage number field 25 (value is “2”) in the communication route storage unit 26 (step 25). Next, the own ID “D” is stored in the transmission source field 23 (step 26). Then, the generated communication frame is sent to the transmission unit 5 to perform wireless communication (step 27).

  In the wireless terminal C, since the value of the current stage number field 25 in step 24 is “1”, the comparison result in step 4 is “YES”. Therefore, the operation is the same as that of the wireless terminal D. In the wireless terminal B, since the value of the current stage number field 25 in step 24 is “0”, the comparison result in step 24 is “NO”. Next, the destination field 22 and the issuer field 21 are compared (step 28). Since “B” is stored in the destination field 22 and “A” is stored in the issuer field 21, the comparison result in step 28 is “NO”. Next, the issuer field 21 is stored in the destination field 22 (step 29). Subsequent operations (step 26 and step 27) are performed in the same manner as the wireless terminal C and the wireless terminal D. Next, in the wireless terminal A, the comparison result in step 24 is “NO”, and the comparison result in step 28 is “YES”. Thus, the received radio field intensity measurement is completed and the result is displayed (step 30).

  Next, an operation when communication fails in the middle of the set communication route as in the example shown in FIG. 6 in which communication between the wireless terminal C and the wireless terminal D has failed will be described with reference to FIG. The processing of the wireless terminal A and the wireless terminal B is the same as the above operation. The operation of the wireless terminal C is the same as that described above until step 9. Since the communication from the wireless terminal C to the wireless terminal D fails, the comparison result in step 10 is “NO”. Next, the communication failure (for example, “F”) is stored in the field of strength 3273 designated by the current stage number field 25 (value is “3”) in the received radio wave strength storage field 27. Next, activation of reply communication (step 12) is executed.

  Next, activation of reply communication performed by the communication frame generation unit 4 of the wireless terminal C will be described. First, a communication frame generated by the wireless terminal C in order to perform reception radio wave intensity measurement is set as a base of the communication frame. Next, a “reception radio wave intensity measurement reply command” is set in the command field 20. Next, the current stage number field 25 is subtracted by 2 and set in the current stage number field 25. At this time, the value of the current stage number field 25 is “1”. Next, the data (value is “B”) extracted from the field of ID1 261 specified in the current stage number field 25 in the communication route storage field 26 is set in the destination field 22, and the own ID “C” is set in the source field. 23. Next, the generated communication frame is sent to the transmission unit 5 to perform wireless communication.

  As described above, according to the embodiment described above, the communication route is specified, and the received radio wave strength between the wireless terminals is measured, stored, and transmitted. Can be measured remotely. Further, by repeating the measurement operation, it is possible to perform brute force measurement of received radio wave strength among all wireless terminals. Furthermore, when the installation configuration of the wireless terminal is changed, measurement limited to the changed location can be performed.

  In addition, when the communication fails, the result of the received radio wave intensity measurement up to the middle is stored and transmitted, so it is possible to remotely measure which wireless terminal has failed the communication.

  Although the received signal strength is measured, stored, and transmitted, the communication status is measured. If link quality such as bit error rate, response time, and transmission speed is measured, stored, and transmitted, the link quality between each terminal is measured. Can be measured.

  In addition, although reply communication is performed using a communication route designated for measurement, communication may be performed by independently constructing a relay route.

It is a block diagram which shows the internal structure of the radio | wireless terminal which comprises the multihop network which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the communication frame used in order to measure the received field strength between the radio | wireless terminals which comprise the multihop network of this invention. It is explanatory drawing in the case of measuring a received radio wave intensity | strength in the path | route of wireless terminal A-> wireless terminal B-> wireless terminal C-> wireless terminal D-> wireless terminal E. It is a flowchart explaining the operation | movement of a received radio wave intensity | strength measurement. It is a flowchart explaining the propagation | transmission operation | movement of a reply communication. It is explanatory drawing when communication fails in the middle of the set communication route.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Reception part, 2 Received radio wave intensity measurement part, 3 Communication frame interpretation part, 4 Communication frame production | generation part, 5 Transmission part, 6 Communication success monitoring part, 20 Command field, 21 Issuer field, 22 Destination field, 23 Transmission field , 24 Total stage number field, 25 Current stage number field, 26 Communication route storage field, 27 Received radio wave intensity storage field.

Claims (2)

A wireless terminal that constitutes a multi-hop network that relays information by relaying a plurality of wireless terminals,
A receiver that receives and demodulates radio waves and captures information;
A received radio field intensity measuring unit that measures the intensity of radio waves received by the receiving unit;
A communication frame interpreter for decoding and analyzing the received communication frame;
A communication frame generation unit for generating a communication frame to be transmitted according to information of the communication frame analyzed by the communication frame interpretation unit;
A transmission unit that modulates the communication frame generated by the communication frame generation unit and radiates the communication frame as a radio wave,
The communication frame stores a command field that stores processing executed by the wireless terminal, an issuer field that stores the number of the wireless terminal that has instructed reception radio wave intensity measurement, and the number of the wireless terminal that is the destination of the communication frame. Destination field, transmission source field that stores the number of the wireless terminal that transmits the communication frame, total number of steps field that stores the number of communication steps required to measure the received signal strength, and the number of communication steps in which the received signal strength measurement is performed Is a current stage number field for storing, a communication route storage field for storing a list of numbers of wireless terminals that perform reception field strength measurement, and a reception field strength storage field for storing measurement results of reception field strength,
The communication frame generator is
When the command field of the received communication frame is interpreted as a received radio wave intensity measurement command by the communication frame interpreter, the received radio wave intensity measured by the received radio wave intensity measurer is extracted and the radio wave of the communication frame is extracted. Store in the field specified by the current stage number in the intensity storage field, add 1 to the current stage field value, store in the current stage field, compare the current stage field value with the total stage field value When the total number of steps in the total number of steps field is equal to or greater than the current number of steps in the current step number field, the ID specified in the current step number field in the communication route storage field is extracted and stored in the destination field, and the own ID is set in the source field. The communication frame generated by storing is sent to the transmission unit,
When the communication frame interpreter interprets that the command field of the received communication frame is a received radio field strength measurement reply command, the value of the current stage number field is decremented by 1 and stored in the current stage number field. If the determination result is large, the ID specified in the current stage number field in the communication route storage unit is extracted and stored in the destination field, and the own ID is transmitted from the sender. The communication frame generated by storing in the field is sent to the transmitter, and if the determination result shows that the value of the current stage number field is 0, the value of the destination field is not the same as the value of the issuer field In this case, the value generated in the source field is stored in the destination field and the self ID is stored in the source field. A wireless terminal constituting a multi-hop network, characterized in that a frame is sent to the transmitter, and the value of the destination field is compared with the value of the issuer field, and if the same, the received radio field strength measurement is completed and the result is displayed. . In the wireless terminal constituting the multi-hop network according to claim 1,
A communication success monitoring unit for confirming that the issued command is received at the destination;
The communication frame generation unit activates the communication success monitoring unit, and stores the communication failure in the field specified by the current stage number field in the received signal strength storage field when confirming the communication failure. A wireless terminal that forms a multi-hop network.

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