JP5992939B2 - Wireless communication terminal, wireless communication system, and wireless communication method - Google Patents

Description

  The present invention relates to a wireless communication terminal, and more particularly to a wireless communication terminal that prevents congestion.

  In recent years, in wireless communication, there is a case where an unnecessarily high wireless output flies over because communication speed and stable communication are emphasized. The number and types of terminals that perform wireless communication are also increasing. In particular, in a region where terminals that perform wireless communication are dense, the possibility of congestion is increasing. When congestion occurs, wireless communication until recovery is interrupted, and the entire network may be affected.

  Therefore, techniques such as Patent Document 1 and Patent Document 2 are disclosed as techniques for improving transmission quality in wireless communication.

  Patent Document 1 uses information related to transmission quality to estimate a bottleneck portion, and divide the effective bandwidth and assign it to each terminal device, thereby providing network follow-up capability, responsiveness, etc. A technique capable of improving and improving transmission quality is disclosed.

  Patent Document 2 discloses a technique for preventing congestion that occurs in a network by controlling the data amount of a relay device by adjusting the balance between self-optimization and overall optimization.

International Publication No. 2009/028185 International Publication No. 2008/035600

  The technique described in Patent Document 1 uses routing information to automate efficient allocation of the transmission band of the entire wireless network. However, there is a problem that the relay device is used and cannot be controlled only by a terminal. there were.

  The technique described in Patent Document 2 has a problem that it cannot be applied when a cooperating relay device is not used.

  An object of the present invention is to solve the above-described problems and enable congestion to be prevented only by control by the terminals even in an area where terminals performing wireless communication are dense.

  In order to solve the above-described problem, the present invention provides a received electric field level management for comparing the received electric field level of a peripheral terminal in a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof. A change terminal determination unit that determines a terminal that lowers the wireless output level from among a plurality of peripheral terminals, and measures the number of hops from the peripheral terminals and investigates the peripheral terminals that are transmitting information redundantly A hop number management unit, and the changed terminal determination unit determines the radio output level from the received field level data of peripheral terminals obtained from the received field level management unit and the hop number data obtained from the hop number management unit. It is characterized by selecting terminals to be reduced.

  The present invention also provides a reception electric field level management unit for comparing received electric field levels of a peripheral terminal and a plurality of peripherals in a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof. A change terminal determination unit that determines a terminal that lowers the radio output level from among the terminals, and a transmission required time of information transmitted from the peripheral terminal is calculated from a transmission time and a reception time of the information transmitted from the peripheral terminal A transmission time management unit, and the changed terminal determination unit wirelessly outputs from the reception field level data of peripheral terminals obtained from the reception field level management unit and the number of transmission time data obtained from the transmission time management unit It is characterized by selecting terminals that lower the level.

  The present invention also provides a reception electric field level management unit for comparing received electric field levels of a peripheral terminal and a plurality of peripherals in a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof. An error rate management unit that obtains an error rate when information is directly transmitted from a peripheral terminal and an error rate when the information is transmitted via a terminal, and a change terminal determination unit that determines a terminal that lowers the wireless output level from among the terminals The changed terminal determination unit is a terminal that lowers the radio output level from the received field level data of peripheral terminals obtained from the received field level management unit and the error rate comparison result obtained from the error rate management unit It is characterized by determining.

  The present invention also provides a reception electric field level management unit for comparing received electric field levels of a peripheral terminal and a plurality of peripherals in a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof. A change terminal determination unit that determines a terminal that lowers the radio output level from among terminals, and a transmission that calculates a transmission required time of information transmitted from a peripheral terminal from a transmission time and a reception time of information transmitted from the peripheral terminal A time management unit, the transmission time management unit selects a peripheral terminal having a plurality of transmission time required for information to be transmitted, calculates each difference and compares it with a predetermined threshold, the change terminal determination unit, The terminal that lowers the radio output level is selected from the received field level data of the peripheral terminal obtained from the received field level management unit and the transmission time difference data obtained from the transmission time management unit. It is.

  Further, the present invention provides a reception electric field level management unit for comparing received electric field levels of peripheral terminals in a wireless communication system in which an arbitrary one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof, and a plurality of peripherals A change terminal determination unit that determines a terminal that lowers the wireless output level from among the terminals, and a hop number management unit that measures the number of hops from the peripheral terminal and investigates the peripheral terminal that is transmitting information redundantly The changed terminal determination unit selects a terminal that lowers the radio output level from the received field level data of the peripheral terminal obtained from the received field level management unit and the hop number data obtained from the hop number management unit. It is characterized by that.

  According to another aspect of the present invention, there is provided a wireless communication method in which an arbitrary one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof, the step of comparing received electric field levels of the peripheral terminals, A terminal for reducing a wireless output level, comprising: determining a terminal that lowers a wireless output level; and measuring a number of hops from a peripheral terminal and investigating a peripheral terminal that transmits information redundantly The step of determining the radio power level is reduced from the data of the received electric field level of the peripheral terminal obtained from the step of comparing the received electric field level of the peripheral terminal and the data of the number of hops obtained from the step of investigating the peripheral terminal. It is characterized by selecting terminals.

  According to the present invention, there is an effect that congestion can be prevented only by control by a terminal even in an area where terminals performing wireless communication are dense.

It is a block diagram which shows the structure of the radio | wireless communication terminal in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the periphery terminal management part which the radio | wireless communication terminal in the 1st Embodiment of this invention has. It is a figure which shows the example of the message format in the 1st Embodiment of this invention. It is a figure which shows the connection state of the peripheral terminal in the 1st Embodiment of this invention. It is a figure which shows the received electric field level and hop number of the periphery terminal in the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the radio | wireless communication terminal in the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the radio | wireless communication terminal in the 1st Embodiment of this invention. It is a figure which shows the reception electric field level and transmission required time of the periphery terminal in the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the radio | wireless communication terminal in the 2nd Embodiment of this invention. It is a figure which shows the received electric field level and error rate management of the periphery terminal in the 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the radio | wireless communication terminal in the 3rd Embodiment of this invention. It is a figure which shows the reception electric field level and transmission required time of the periphery terminal in the 4th Embodiment of this invention. It is a figure which shows the reception electric field level and transmission required time of the periphery terminal in the 5th Embodiment of this invention.

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

(First embodiment)
The configuration of the wireless communication terminal according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a configuration of a wireless communication terminal 101 according to the first embodiment of the present invention.

  The wireless communication terminal 101 includes a control unit 102, a wireless unit 103, a peripheral terminal management unit 104, a hop number calculation unit 105, a memory 106, and a communication quality message management unit 107.

  The control unit 102 controls message generation other than the communication quality management message and the wireless output level. The wireless unit 103 can perform not only communication via a base station or a repeater but also communication with a peripheral terminal without passing through a base station or a repeater, and transmits and receives messages. The peripheral terminal management unit 104 determines a terminal whose wireless output level should be lowered based on the peripheral terminal data stored in the memory 106. The hop number calculation unit 105 calculates the hop number to be added to the transmission message addressed to the peripheral terminal. The memory 106 stores the wireless output level of the wireless communication terminal 101, data of peripheral terminals, and the like. The communication quality message management unit 107 analyzes creation of communication quality management messages and received messages.

  FIG. 2 is a diagram showing details of the peripheral terminal management unit 104 shown in FIG.

  The peripheral terminal management unit 104 includes a reception electric field level management unit 201, a hop number management unit 202, a transmission time management unit 203, an error rate management unit 204, and a changed terminal determination unit 205.

  The received electric field level management unit 201 collects the received electric field level data of the peripheral terminals stored in the memory 106 and manages the received electric field level for each peripheral terminal. The number-of-hops management unit 202 aggregates the number of hops used by peripheral terminals when transmitting a message, and manages the number of hops for each route from the peripheral terminal to the own terminal (the transmission route described later). The transmission time management unit 203 calculates and manages the required transmission time for each peripheral terminal from the message transmission time and the reception time stored in the memory 106. The error rate management unit 204 aggregates error rate data stored in the memory 106 and manages the error rate for each peripheral terminal. The changed terminal determination unit 205 determines a terminal whose wireless output is to be changed from the management information of the received electric field level management unit 201, the hop number management unit 202, the transmission time management unit 203, and the error rate management unit 204.

  The transmission time management unit 203 and the error rate management unit 204 are not used in the first embodiment, but are used in the second embodiment and later.

  A communication quality management message transmitted and received between the terminal and the peripheral terminal in this embodiment will be described.

  FIG. 3 is a diagram illustrating an example of a message format. FIG. 3 shows an example of the communication quality management message. The communication quality management message includes a header, a message ID, a transmission channel, transmission timing, the number of hops, a transmission time, a message transmission time, an error rate, an FCS (Frame Check Sequence), and the like. The “header” is composed of a header of each layer such as a wireless protocol (for example, IEEE802.11b) or IP. “Message ID” indicates the type of message transmitted and received in the present embodiment. For example, “0” is set to “communication quality management message”, and “1” is set to “wireless output reduction message”. “Data” stores information such as transmission source terminal information and communication environment used in the present embodiment. “FCS” is data added to check whether there is an error in the received frame. For example, it is composed of CRC (Cyclic Redundancy Check) (cyclic redundancy code).

  Next, “data” in the message format will be described. The “transmission source terminal” stores information for specifying the transmission source terminal, such as a MAC (Media Access Control) address. It is assumed that this “transmission source terminal” cannot be rewritten for each via terminal. The “transmission terminal” stores information for specifying the transmission terminal, such as a MAC address. This “transmission terminal” is rewritten for each via terminal.

  “Sequence ID” is information for specifying a message to be transmitted. For example, a sequence number added every time transmission is performed is stored. This “sequence ID” is not rewritten for each via terminal.

  The “transmission channel” stores information such as a radio channel and a radio frequency used when the transmission source terminal transmits a message. This “transmission channel” is rewritten for each via terminal. “Transmission timing” stores information such as a transmission timing at which the transmission source terminal transmits a message, such as a time slot. This “transmission timing” is rewritten for each via terminal.

  The “hop count” stores information such as the number of terminals that pass through until reaching the target terminal. This “hop count” is rewritten for each via terminal. Every time it passes through the terminal, “1” is added to the number of hops “n” recorded in the received message and stored as “n + 1”.

  “Transmission time” stores the time when the transmission source terminal and the relay terminal transmit this message. This “transmission time” is rewritten by the relay terminal. “Message transmission time” stores the time at which the transmission source terminal transmits this message. This “message transmission time” is not rewritten by the relay terminal. When the transmission source terminal transmits a message, “transmission time” and “message transmission time” are the same information. Thereafter, when transmitting via, “transmission time” changes, but “message transmission time” does not change.

  FIG. 4 shows an arrangement example of the transmission source terminal, the relay terminal, and the reception terminal in the first embodiment.

  Considering “communication path from terminal C → terminal B → terminal A” in FIG. 4, terminal C is a transmission source terminal, terminal B is a transit terminal, terminal A is a reception terminal, and “transmission source terminal” is always terminal C. is there.

  Here, the terminal A is a terminal that manages information transmitted from other terminals and controls the other terminals. The terminal A is a terminal that determines a terminal whose wireless output is to be changed. In each embodiment of the present invention, all the wireless communication terminals 101 are provided with this function, and mutually control wireless output. The operation in which terminal A controls other terminals is described below.

  Information when a message of “sequence ID: 3” is transmitted from the terminal C is “transmission time 12:31:48” and “message transmission time = 12: 31: 48”. When this message is transmitted via the terminal B, it is rewritten to “transmission time = 12: 31: 51”, but “message transmission time = 12: 31: 48” is not rewritten. “Error rate” stores the communication quality and the like when the via terminal communicates with the preceding terminal. This “error rate” is rewritten for each via terminal.

  For example, considering the “communication path of terminal C → terminal B → terminal A” in FIG. 4, terminal C is a source terminal, terminal B is a transit terminal, terminal A is a receiving terminal, and terminal B is terminal C-terminal B. Stores the communication quality when communicating between each other. Note that terminal C stores “0” because it is a transmission source terminal and there is no preceding terminal. In the “error rate”, it is also possible to estimate and store the error rate of the entire communication path from the error rate measured when the transit terminal communicates with the preceding terminal and the “error rate” stored in this message. . As a method of estimating the error rate, when considering a series of communication paths p including a via terminal, the terminal having the highest error rate can be considered as the error rate of the communication path p.

  That is, the error rate of the peripheral terminal measured by the terminal (source terminal or transit terminal) is compared with the “error rate” in the communication quality management message, and the one with the higher value is set as the “error rate” in the communication quality management message. How to store.

  For example, in the case of the communication path of terminal H-terminal G-terminal D-terminal A in FIG. 4, the error rate of terminal G measured by terminal D is “0.1%”, and communication received by terminal D from terminal G If the “error rate” in the quality control message is “0.5%”, the terminal D estimates the latter as the error rate of a series of communication paths, and sets “0. 5% "is stored.

  In FIG. 3, the message ID of the communication quality management message is 0. The wireless communication terminal 101 stores the information of the terminal itself as described above and transmits it to the peripheral terminals. In addition, a communication quality management message from a peripheral terminal is received. When the communication quality management message from the peripheral terminal is transferred, the information of the own terminal is added to the communication quality management message.

  Further, the wireless output reduction message is obtained by setting “message ID” in the communication quality management message to “1”, and the data part is common. The terminal that is the destination of the wireless output reduction message reduces the transmission output by an arbitrary fixed value (for example, 0.5 dBm).

Also, by adding “Specify transmission output reduction level” to the data part and setting the value of the transmission output that the transmission source terminal wants to decrease, the transmission output of the transmission source is reduced by the specified transmission output. Is also possible. (For example, if the transmission output of terminal C is 15 dBm, setting “transmission output decrease level designation: 3” sets the transmission output of terminal C to 15-3 = 12 dBm.)
It is also possible to change to the designated transmission output by adding “transmission output level designation” to the data portion. (For example, if the transmission output of terminal C is 15 dBm, setting “transmission output level specification: 10” sets the transmission output of terminal C to 10 dBm.)
The operation of the radio communication terminal according to the first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, the wireless unit 103 measures the received electric field level of the peripheral terminal and stores the result in the memory 106.

  The communication quality message management unit 107 analyzes a message received from a peripheral terminal, and stores data necessary for wireless output level change determination in the memory 106. In the first embodiment, a case will be described in which a terminal whose wireless output level is to be changed is determined based on the number of hops of a received message and the received electric field level of a peripheral terminal.

  The wireless communication terminal 101 transmits and receives a communication quality management message from the peripheral terminal at the wireless unit 103. The communication quality management message records the transmission channel and transmission timing of the transmission source terminal, the number of hops at the time of message transmission, and the like. The number of hops is the number of terminals that pass through to reach the target terminal.

  The relationship with peripheral terminals will be described with reference to FIGS.

  In FIG. 4, a terminal that determines a terminal having a reduced wireless output level is referred to as terminal A. The peripheral terminals of terminal A are terminal B to terminal J. The terminal A analyzes the received communication quality management message and extracts information necessary for calculating the received electric field level of the peripheral terminals and the number of hops of each message.

  FIG. 5 is an example of extraction results of terminals whose wireless output level should be lowered. The reception electric field level management unit 201 refers to the reception electric field level of the peripheral terminal measured by the radio unit 103 and the transmission channel and transmission timing of the transmission source terminal attached to the message from the memory 106 and receives the electric field exceeding the threshold. A terminal having a level is determined as a terminal having a high received electric field level.

  In FIG. 5, when the threshold is set to 18 dBm, the received electric field level management unit 201 of the terminal A determines that the terminal C, the terminal D, and the terminal H are terminals having a high received electric field level. The determination result of the reception electric field level management unit 201 is stored in the memory 106.

  Terminals that transmit a message directly to terminal A, that is, terminals that transmit a message in one hop are terminal B, terminal C, terminal D, terminal E, and terminal F. Terminals that transmit messages via other terminals, that is, terminals that transmit messages in two hops are terminal C, terminal G, terminal H, terminal I, and terminal J. In this case, the hop count management unit 202 determines that the terminal transmitting the message redundantly is the terminal C. The hop number management unit 202 stores this determination result in the memory 106.

  The changed terminal determination unit 205 of the terminal A refers to the determination results of the received electric field level management unit 201 and the hop number management unit 202 from the memory 106, and receives a duplicate message with a high received electric field level. Determine which terminal is on.

  In the example of FIG. 5, terminal C is the corresponding terminal. If there are a plurality of hops, it can be determined that there are a plurality of communication paths because the transmission power of the transmission source terminal is large. Considering communication between the terminal C and the terminal A, when the transmission power of the terminal C is large, there are “communication path: terminal C-terminal A” and “communication path: terminal C-terminal B-terminal A”. Here, from the viewpoint of the terminal A and the terminal C, it is only necessary to be able to communicate with any one of the paths, so there is no problem even if “communication path: terminal C−terminal A” is not provided. Further, when viewed from “communication path: terminal C-terminal B-terminal A”, “communication path: terminal C-terminal A” is an interference wave, and in order to improve the communication environment, “communication path: terminal C”. It is preferable to delete “C-terminal A”. Therefore, it is determined that the transmission power of terminal C can be reduced.

  From this determination result, terminal A transmits a message for instructing terminal C to decrease the wireless output level. The terminal C that has received the message lowers the wireless output level at the control unit 102.

  The operation of the peripheral terminal management unit 104 will be described.

  The received electric field level management unit 201 refers to the received electric field level determination threshold value stored in the memory 106, the transmission channel and transmission timing of the transmission source terminal, and the received electric field level measurement result of the radio unit 103, and receives the received electric field level from the threshold value. A terminal having a high electric field level is determined. The reception electric field level management unit 201 stores this determination result in the memory 106. Further, the hop number management unit 202 refers to the number of hops of the received message for each peripheral terminal stored in the memory 106, and the terminal that transmits the message with one hop and the terminal that transmits the message with two or more hops. A terminal corresponding to both is determined, and the determination result is stored in the memory 106.

  Then, the changed terminal determination unit 205 refers to the results of the received electric field level management unit 201 and the hop number management unit 202 from the memory 106, and identifies a terminal corresponding to both results as a terminal whose wireless output level should be reduced. To do.

  The changed terminal determination unit 205 instructs the control unit 102 to create a wireless output reduction message. The control unit 102 creates a wireless output reduction message. The created message is transmitted from the wireless unit 103 to a terminal whose wireless output level should be lowered.

  In this embodiment, it is possible to configure only the transmission source terminal information and the transmission terminal information, the sequence ID, the transmission channel, the transmission timing, and the number of hops in the message format of FIG. The format of the wireless output reduction message is the same as the message format of FIG. The transmission time, message transmission time, and error rate in the data shown in FIG. 3 are used in the second and subsequent embodiments.

  The wireless output decrease message is a message transmitted to the corresponding terminal when the changed terminal determination unit 205 determines a terminal whose wireless output level should be decreased, and has a message ID unique to this message. In FIG. 3, the message ID of the wireless output reduction message is 1.

  The terminal that has received the message discriminates the message ID, and if it is the ID of the wireless output reduction message, the wireless output level is reduced. It is possible to lower a certain arbitrary value (for example, 0.5 dBm) every time a message is received, and it is also possible to record an arbitrary value in the message format and lower the recorded value.

  The operation when transmitting / receiving a communication quality management message will be described below.

  When the communication quality management message is transmitted, the communication quality message management unit 107 or the control unit 102 uses the data part information (excluding the hop number) described in the message format example of FIG. Is given to the communication quality message management unit 107. The hop count calculation unit 105 sets “1” to the hop count when generating a new message, and “1” to the hop count “n” recorded in the received message when transferring a message from another terminal. ”And added to the communication quality message management unit 107 as“ n + 1 ”.

  When the communication quality management message is received, the control unit 102 analyzes the received message and stores data related to the peripheral terminal in the memory 106. As soon as a certain amount of data, for example, 10 pieces of data are accumulated, or at regular intervals (for example, every 10 seconds), the peripheral terminal management unit 104 is started to determine a terminal whose wireless output is reduced.

  FIG. 6 is a flowchart showing an operation when a wireless output reduction message is transmitted.

  When wireless communication terminal 101 receives a communication quality management message at wireless section 103, wireless communication terminal 101 stores this message in memory 106 and notifies communication quality message management section 107. This process may be performed via the control unit 102 (S601).

  Upon receiving the notification from the wireless unit 103, the communication quality message management unit 107 analyzes the communication quality management message received in S601 and stores the data recorded in the message such as the transmission channel, the message transmission time, and the number of hops in the memory 106. To do. At this time, the communication quality message management unit 107 stores the reception time in the memory 106 for each message. The reception time may be stored by the wireless unit 103 in S601 (S602).

  The control unit 102 periodically checks the number of communication quality management messages stored in the memory 106. If a certain amount (for example, 10) of data is accumulated, the control unit 102 sends a communication quality management message to the peripheral terminal management unit 104. Instructs the start of analysis.

  Also, the wireless unit 103 is instructed to measure the received electric field level (Yes in S603). If the number of communication quality management messages has not reached a certain number, the process returns to S601 (No in S603). Note that it is possible to instruct the peripheral terminal management unit 104 to start analyzing the communication quality management message at a timing at which the memory 106 is periodically checked regardless of the number of communication quality management messages.

  Receiving the instruction from the control unit 102 from Yes in S603, the wireless unit 103 measures the received electric field level of the peripheral terminal and stores the measurement result in the memory 106 (S604). This process may be performed after the following S605.

  The peripheral terminal management unit 104 that has received an instruction from the control unit 102 from Yes in S603 instructs the reception electric field level management unit 201, which is an internal block, to determine a change candidate terminal.

  Since each terminal is individually assigned a transmission channel and transmission timing, it is possible to receive data transmitted by a specific terminal from information on the transmission channel and transmission timing in the communication quality management message. The received electric field level is measured at this timing, and the received electric field strength of the specific terminal is measured.

  In this way, the reception electric field level management unit 201 associates the transmission channel and transmission timing information in the communication quality management message with the reception electric field level measurement value measured in S604, and collects the electric field level statistics for each peripheral terminal, The statistical result is stored in the memory 106.

  Also, the received electric field level management unit 201 compares this statistical result with an arbitrary threshold value stored in the memory 106. If the received electric field level is greater than the threshold value, the received electric field level is determined as a change candidate terminal and stored in the memory 106. The determination unit 205 is notified (S605).

  The peripheral terminal management unit 104 that has received an instruction from the control unit 102 from Yes in step S <b> 603 instructs the hop number management unit 202 that is an internal block to determine a change candidate terminal. The hop count management unit 202 refers to the hop count of the received message for each peripheral terminal stored in the memory 106 and discriminates between a terminal transmitting a message with one hop and a terminal transmitting a message with two or more hops. Then, the determination / determination result is stored in the memory 106 as a change candidate terminal (message multiplexing terminal) as a terminal having two or more hops, and is notified to the change terminal determination unit 205 (S606).

  The change terminal determination unit 205 refers to the determination result by the reception electric field level management unit 201 in S605 and the determination result by the hop number management unit 202 in S606 from the memory 106, and selects a change candidate terminal corresponding to both results. Then, it is determined as a terminal (changed terminal) whose wireless output level should be lowered (S607). The peripheral terminal management unit 104 notifies the control unit 102 of the determination result of the changed terminal determination unit 205 that is an internal block.

  The control unit 102 that has received the determination result from the peripheral terminal management unit 104 creates a wireless output reduction message for each changed terminal, and notifies the wireless unit 103 (S608).

  The wireless unit 103 that has received the wireless output reduction message for each changed terminal from the control unit 102 transmits the wireless output reduced message to the changed terminal determined by the changed terminal determining unit 205 (S609).

  With reference to FIG. 7, the operation when receiving the wireless output reduction message will be described. FIG. 7 is a flowchart showing an operation when a wireless output reduction message is received.

  When the wireless communication terminal 101 (terminal C in the example of FIG. 5) receives the wireless output decrease message, the wireless unit 103 stores the message in the memory 106 and notifies the communication quality message management unit 107 (S701). This process may be performed via the control unit 102.

  Upon receiving the notification from the wireless unit 103, the communication quality message management unit 107 analyzes the wireless output decrease message received in (S701), and stores the data recorded in the message such as transmission output decrease level designation and transmission output level designation in the memory. It stores in 106. The communication quality message management unit 107 instructs the wireless unit 103 to decrease the wireless output level (S702). Similar to S <b> 701, this process may be performed via the control unit 102.

  The wireless unit 103 that receives the notification from the communication quality message management unit 107 or the control unit 102 reduces the wireless output level. The radio unit 103 decreases a certain arbitrary value (for example, 0.5 dBm) every time a message is received. If “transmission output reduction level designation” is stored in the message, the “transmission output level reduction designation” is referred to from the memory 106 to reduce the transmission output of the transmission source by the designated transmission output. Is possible.

  Alternatively, when “transmission output level designation” is stored in the message, it is possible to refer to “transmission output level designation” from the memory 106 and change the transmission output to the designated transmission output. The communication quality message management unit 107 or the control unit 102 can also set the transmission output level in the wireless unit 103 by referring to “transmission output level decrease designation” and “transmission output level designation” from the memory 106. (S703).

(Second Embodiment)
The operation of the second embodiment will be described with reference to FIGS. The second embodiment of the present invention is a method of making a determination using the received electric field level management unit 201 and the transmission time management unit 203 in the peripheral terminal management unit 104. In the first embodiment, the operation of the peripheral terminal management unit 104 is replaced with the following.

  As in the first embodiment, a terminal that determines a wireless output level lowered terminal in FIG. The peripheral terminals of terminal A are terminal B to terminal J.

  FIG. 8 is a diagram showing the received electric field level and the required transmission time of the peripheral terminal in the second embodiment of the present invention. FIG. 8 shows an example of extraction results of terminals whose wireless output level should be lowered in the second embodiment. FIG. 9 is a flowchart illustrating an operation when the wireless communication terminal 101 transmits a wireless output decrease message in the second embodiment.

  9, S901 to S905 and S907 to S909 are equivalent to S601 to S605 and S607 to S609 in FIG. 6. The operation of S606 in FIG. 6 is replaced with the following processing (S906).

  In step S903, the transmission time management unit 203, which is an internal block of the peripheral terminal management unit 104 that has received an instruction from the control unit 102, is instructed to determine a change candidate terminal. The transmission time management unit 203 refers to the message transmission time included in each message stored in the memory 106 and the reception time stored in the memory 106 in S902, and calculates the required transmission time. The statistics for each transmission source terminal are obtained from the calculation result, the determination result is stored in the memory 106 as a change candidate terminal for a terminal having a plurality of transmission time data, and notified to the change terminal determination unit 205 (S906).

  The operation of the peripheral terminal management unit 104 in the second embodiment will be described.

  The reception electric field level management unit 201 refers to the transmission channel and transmission timing of the transmission source terminal stored in the memory 106 and the reception electric field level measurement result, and determines a terminal having a high reception electric field level around the wireless communication terminal 101. The reception electric field level management unit 201 stores the determination result in the memory 106. The communication quality control message is given a message transmission time in addition to the transmission channel of the transmission source terminal.

  This message transmission time is not updated when the transit terminal retransmits. The communication quality message management unit 107 stores the reception time in the memory 106 when a message is received. The transmission time management unit 203 refers to the message transmission time and reception time of each message from the memory 106 and calculates the required transmission time. If there is a terminal that is classified for each transmission source terminal and a plurality of required transmission times are extracted with the same message, it can be determined that there are a plurality of communication paths because the transmission power of the transmission source terminal is large.

  For example, considering communication between the terminal C and the terminal A, when the transmission power of the terminal C is large, “communication path: terminal C-terminal A” and “communication path: terminal C-terminal B-terminal A” exist. . Here, from the viewpoint of the terminal A and the terminal C, it is only necessary to be able to communicate with any one of the paths, so there is no problem even if “communication path: terminal C−terminal A” is not provided. Further, when viewed from “communication path: terminal C-terminal B-terminal A”, “communication path: terminal C-terminal A” is an interference wave, and in order to improve the communication environment, “communication path: terminal C-terminal C”. It is preferable to delete “terminal A”.

  Therefore, it is determined that the transmission power of the terminal C can be reduced, and the terminal C is set as a change candidate terminal. The transmission time management unit 203 stores this determination result in the memory 106.

  The change terminal determination unit 205 of the terminal A refers to the determination results of the reception electric field level management unit 201 and the transmission time management unit 203 from the memory 106, and the reception electric field level is higher than the set threshold value and is duplicated. Determine the terminal sending the message.

  In the example of FIG. 8, when terminals C, D, and H have higher reception electric field levels than terminal A, and terminals B and C have a plurality of required transmission times, It is determined that the terminal whose level should be lowered is the terminal C. The terminal A transmits a message for instructing the terminal C to lower the wireless output level, and the terminal C that has received the message lowers the wireless output level by the control unit 102.

  In this embodiment, it is possible to configure only the transmission source terminal information, transmission terminal information, sequence ID, transmission channel, transmission timing, and message transmission time in the message format of FIG.

(Third embodiment)
The operation of the third embodiment of the present invention will be described with reference to FIGS. The third embodiment is a method of making a determination using the received electric field level management unit 201 and the error rate management unit 204 in the peripheral terminal management unit 104. In the first embodiment, the operation of the peripheral terminal management unit 104 is replaced with the following. As in the first embodiment, a terminal that determines a wireless output level lowered terminal in FIG. The peripheral terminals of terminal A are terminal B to terminal J.

  FIG. 10 is a diagram showing received electric field level and error rate management of peripheral terminals in the third embodiment of the present invention. FIG. 10 shows an example of extraction results of terminals whose wireless output level should be lowered in the second embodiment.

  FIG. 11 is a flowchart illustrating an operation when the wireless communication terminal 101 transmits a wireless output decrease message in the third embodiment. 11, S111 to S115 and S117 to S119 are equivalent to S601 to S605 and S607 to S609 in FIG. The operation in S606 in FIG. 6 is replaced with the following process S116.

  In step S113, the peripheral terminal management unit 104 that has received an instruction from the control unit 102 instructs the error rate management unit 204, which is an internal block, to determine a change candidate terminal. Here, a transmission source terminal having a via terminal has the following two communication paths. One is a path for communication without a transit terminal (hereinafter referred to as direct transmission), and the other is a path for communication via a transit terminal (hereinafter referred to as transit transmission).

  The error rate management unit 204 refers to the transmission terminal and transmission source terminal of each message stored in the memory 106, and identifies the transmission source terminal having direct transmission from the same message in the transmission terminal and transmission source terminal in the message. To do. Further, when the transmission terminal and the transmission source terminal in the message are different, it is specified as the transmission source terminal having the via transmission. From this result, the error rate management unit 204 extracts a transmission source terminal that has a direct transmission and a direct transmission.

  The error rate of the transit terminal used for transit transmission and the error rate of the sender terminal are referred to from the memory 106, and when the error rate of the transit terminal is lower than the error rate of the sender terminal, the sender terminal is set as the change candidate terminal. The determination result is stored in the memory 106 and notified to the changed terminal determination unit 205 (S116). Here, the error rate stored in the memory 106 in S114 is used.

  The operation of the peripheral terminal management unit 104 in the third embodiment will be described.

  The reception electric field level management unit 201 refers to the transmission channel and transmission timing of the transmission source terminal stored in the memory 106 and the reception electric field level measurement result, and determines a terminal having a high reception electric field level around the wireless communication terminal 101.

  The reception electric field level management unit 201 stores the determination result in the memory 106. The error rate management unit 204 refers to the error rate of each message from the memory 106 and compares it for each transmission source terminal. The communication quality is better on the route with the lower error rate. A path with low communication quality becomes an interference wave of a path with high communication quality. If the communication path (hereinafter referred to as direct transmission) with no via terminal is lower in communication quality, it is better to reduce the wireless output level of the transmission source to only the path (hereinafter referred to as via transmission) that communicates via the transit terminal. Better communication is possible. Therefore, among the terminals that are directly transmitted and transmitted via the direct transmission, the terminal having the higher error rate in the direct transmission is set as the change candidate terminal.

  In terminal C in the error rate management table of FIG. 10, the error rate is higher in direct transmission. On the other hand, terminal B has a higher error rate for via transmission. In this case, the change candidate terminal is determined as the terminal C. The error rate management unit 204 stores this determination result in the memory 106.

  The changed terminal determination unit 205 of the terminal A refers to the determination results of the received electric field level management unit 201 and the error rate management unit 204 from the memory 106, and has an error rate with a higher reception electric field level and higher direct transmission. The terminal is determined.

  In the example of FIG. 10, terminal C is a corresponding terminal. Terminal A transmits a message instructing terminal C to decrease the wireless output level. The terminal C that has received the message lowers the wireless output level at the control unit 102.

  In the present embodiment, the data portion in the message format of FIG. 3 can be configured only with transmission source terminal information, transmission terminal information, sequence ID, transmission channel, transmission timing, and error rate.

(Fourth embodiment)
The operation of the fourth embodiment of the present invention will be described with reference to FIGS. The fourth embodiment is a method of determining by increasing the parameters referred to by the transmission time management unit 203 in addition to the second embodiment. In the fourth embodiment, the transmission time management unit 203 adds a difference time between direct transmission and via transmission as a parameter. The operation of the transmission time management unit 203 in the peripheral terminal management unit 104 of the second embodiment is replaced with the following.

  As in the first embodiment, a terminal that determines a wireless output level lowered terminal in FIG. The peripheral terminals of terminal A are terminal B to terminal J.

  FIG. 12 is a diagram showing the received electric field level and the required transmission time of the peripheral terminal in the fourth embodiment of the present invention. FIG. 12 shows an example of the extraction result of the terminals whose wireless output level should be lowered in the fourth embodiment. The operation flow when the wireless communication terminal 101 transmits the wireless output reduction message in the fourth embodiment is the same as the operation flow in the second embodiment of FIG. In the fourth embodiment, the following processing is added to S906 in FIG.

  The transmission time management unit 203 refers to the message transmission time included in each message stored in the memory 106 and the reception time stored in the memory 106 in S902, and calculates the required transmission time. Statistics for each transmission source terminal are obtained from the calculation result, and a terminal having a plurality of required transmission times is specified. At that time, the plurality of required transmission times are arranged in order, and each difference is taken. The transmission time management unit 203 compares the calculated difference with an arbitrary threshold value stored in the memory 106. If the difference is equal to or smaller than the threshold value, the determination result is stored in the memory 106 as a change candidate terminal, and the change terminal determination unit 205 Notice.

  The transmission time management unit 203 refers to the message transmission time and reception time of each message from the memory 106 and calculates the required transmission time. They are classified for each transmission source terminal, arranged in order of required time, and each difference is taken. When this difference is smaller than a threshold value (for example, 500 mS), it can be estimated that the retransmission process due to an error or the like in the wireless section does not occur and the communication quality is good. In other words, it can be considered that any path can be deleted.

  Also, the existence of a plurality of communication paths means that, as described in the first embodiment, the communication paths are interference waves, and any one of the paths is deleted in order to improve the communication environment. Is preferable. Further, the presence of a plurality of communication paths is considered that a plurality of terminals are received and a plurality of communication paths are generated because the transmission power of the transmission source terminal is large. From this, it is determined that the transmission power of the transmission source terminal can be reduced.

  On the other hand, when the difference is greater than or equal to a threshold value (for example, 500 mS), retransmission processing due to errors or the like in the radio section occurs frequently, and it is estimated that the communication quality is poor. Therefore, since there is no merit by reducing the communication path, transmission power control for the transmission source terminal is not performed.

  In the table of required transmission times in FIG. 12, terminals B and C have a plurality of required transmission times at the same transmission source terminal. First, for terminal B, the difference between communication path 1 and communication path 2 is “900 mS”, which exceeds the threshold (500 mS). Next, the difference between the communication path 3 and the communication path 4 for the terminal C is “300 mS”, which is within the threshold (500 mS). Therefore, the changed terminal candidate in the transmission time management unit 203 is the terminal C. The transmission time management unit 203 stores this determination result in the memory 106.

For the threshold value, the terminal manager may use the difference time of the terminal having the desired communication quality as the threshold value.
For example, the desired difference time threshold value x is calculated as follows. When the retransmission time a is assumed to be 50 [mS] and the communication quality desired by the terminal manager is defined as “the number of retransmissions b = 10”,
Threshold x = retransmission time a × number of retransmissions b = 50 [mS] × 10 = 500 [mS].

  The changed terminal determination unit 205 refers to the results of the reception electric field level management unit 201 and the transmission time management unit 203 from the memory 106, and identifies a terminal corresponding to either result as a terminal whose wireless output should be reduced.

  In the fourth embodiment, it is possible to configure only the transmission source terminal information, transmission terminal information, transmission channel, transmission timing, sequence ID, and message transmission time in the message format of FIG.

(Fifth embodiment)
The operation of the fifth embodiment of the present invention will be described with reference to FIGS. The fifth embodiment of the present invention has a configuration in which a hop number management unit 202 is added to the fourth embodiment. In the fourth embodiment, a threshold value for the required transmission time, which was constant, is set for each transmission route. As a threshold used for determination by the transmission time management unit 203 in the fifth embodiment, “number of hops × processing time in relay terminal + α” is set in consideration of each transmission route.

The difference time between direct transmission and via transmission is the sum of the processing time in the via terminal and the extra time required for via transmission.
When “the number of hops × the processing time in the via terminal + α” is set as a threshold,
Here, if threshold value ≧ difference time, the extra time required for transmission is a negative value, that is, the communication quality of direct transmission and via transmission is comparable.

  Further, if threshold value <difference time, the extra time required for transmission is a positive value, that is, communication quality is worse in the case of via transmission than direct transmission. Α corresponds to “transmission delay time”.

  For example, in FIG. 13, it is assumed that the processing time in the via terminal is 300 mS and α = 10 mS. For the communication path 11, the threshold is 2 hops of terminal H → terminal G → terminal A, so the threshold is 2 × 300 (ms) +10 (ms) = 610 (ms). Therefore, for the communication path 11, the threshold value and the difference are the same.

  In FIG. 13, the time difference between the communication path 3 and the communication path 4 is 300 mS, which is equal to or less than the threshold value.

  In FIG. 13, the terminal C and the terminal H with a small difference can be selected from the table of required transmission times, and when the terminal C and the terminal H are selected from the terminals with the high reception electric field level in the table of the reception electric field levels of the peripheral terminals, You can choose.

  When the difference in FIG. 13 is equal to or smaller than the threshold value, it can be estimated that retransmission processing due to an error or the like in the wireless section does not occur and the communication quality is good. Therefore, it can be considered that any path can be deleted.

  Also, the existence of a plurality of communication paths means that, as described in the first embodiment, the communication paths are interference waves, and any one of the paths is deleted in order to improve the communication environment. Is preferable. Further, the presence of a plurality of communication paths is considered that a plurality of terminals are received and a plurality of communication paths are generated because the transmission power of the transmission source terminal is large. From this, it is determined that the transmission power of the transmission source terminal can be reduced.

The subsequent processing is the same as in the fourth embodiment.
In this embodiment, it is possible to configure only the transmission source terminal information, transmission terminal information, transmission channel, transmission timing, sequence ID, number of hops, and message transmission time in the message format of FIG.

  As described above, according to the present embodiment, congestion can be prevented only by control by the terminals, even in an area where the terminals performing wireless communication are dense.

  Further, according to the present embodiment, the terminals manage each other and automatically suppress unnecessary wireless output, so that it is possible to reduce the power consumption of the terminals. Moreover, it is possible to adjust a radio | wireless output for every terminal as the whole system.

  In the first to fourth embodiments, one terminal is selected, but a plurality of terminals may be selected.

  The present invention is not limited to the above-described embodiment, and can be implemented with various changes and modifications without departing from the gist of the present invention.

A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1)
In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
Measuring the number of hops from the peripheral terminal, hop number management unit to investigate the peripheral terminal that is transmitting information redundantly,
Have
The change terminal determination unit, the reception field level data of the peripheral terminal obtained from the reception field level management unit, the hop number data obtained from the hop number management unit,
A wireless communication terminal characterized in that a terminal that lowers the wireless output level is selected.
(Appendix 2)
The wireless communication terminal according to supplementary note 1, wherein peripheral terminals having a reception electric field level higher than a set threshold and a plurality of the hop counts are selected as terminals for lowering the wireless output level.
(Appendix 3)
The wireless communication terminal according to Supplementary Note 1 or 2, wherein the selection is performed when a predetermined amount of the received electric field level data and the hop count data is accumulated or at predetermined time intervals.
(Appendix 4)
In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
A transmission time management unit for calculating a transmission time of information transmitted from the peripheral terminal from a transmission time and a reception time of information transmitted from the peripheral terminal;
Have
The change terminal determination unit, the reception field level data of the peripheral terminal obtained from the reception field level management unit, the number of transmission time data obtained from the transmission time management unit,
A wireless communication terminal characterized in that a terminal that lowers the wireless output level is selected.
(Appendix 5)
The wireless communication terminal according to supplementary note 4, wherein peripheral terminals having a reception electric field level higher than a set threshold value and having a large number of data for the transmission time are selected as terminals for lowering the wireless output level.
(Appendix 6)
In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
An error rate management unit for obtaining an error rate when the information is directly transmitted from the peripheral terminal and an error rate when the information is transmitted via the peripheral terminal;
Have
The change terminal determination unit, the reception field level data of the peripheral terminal obtained from the reception field level management unit, the error rate comparison result obtained from the error rate management unit,
A wireless communication terminal, wherein a terminal that lowers a wireless output level is determined.
(Appendix 7)
In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
A transmission time management unit for calculating a transmission time of information transmitted from the peripheral terminal from a transmission time and a reception time of information transmitted from the peripheral terminal;
Have
The transmission time management unit selects the peripheral terminals having a plurality of transmission required times of the information to be transmitted, calculates each difference, and compares the difference with a predetermined threshold value.
The change terminal determination unit, the reception field level data of the peripheral terminal obtained from the reception field level management unit, the transmission time difference data obtained from the transmission time management unit,
A wireless communication terminal characterized in that a terminal that lowers the wireless output level is selected.
(Appendix 8)
The wireless communication terminal according to appendix 7, wherein a peripheral terminal whose transmission time difference data is equal to or less than the threshold is selected as a terminal for lowering a wireless output level.
(Appendix 9)
In a wireless communication system in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
Measuring the number of hops from the peripheral terminal, hop number management unit to investigate the peripheral terminal that is transmitting information redundantly,
Have
The change terminal determination unit, the reception field level data of the peripheral terminal obtained from the reception field level management unit, the hop number data obtained from the hop number management unit,
A wireless communication system, wherein a terminal that lowers a wireless output level is selected.
(Appendix 10)
In a wireless communication method in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
Comparing received electric field levels of the peripheral terminals;
Determining a terminal that lowers a wireless output level from among the plurality of peripheral terminals;
Measuring the number of hops from the peripheral terminal, investigating the peripheral terminal transmitting information redundantly;
Have
The step of determining a terminal that lowers the radio power level includes the received electric field level data of the peripheral terminal obtained from the step of comparing the received electric field level of the peripheral terminal and the hop obtained from investigating the peripheral terminal. Number data and
A wireless communication method characterized by selecting a terminal whose wireless output level is reduced from the above.
(Appendix 11)
In a wireless communication system in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
A transmission time management unit for calculating a transmission time of information transmitted from the peripheral terminal from a transmission time and a reception time of information transmitted from the peripheral terminal;
Have
The change terminal determination unit, the reception field level data of the peripheral terminal obtained from the reception field level management unit, the number of transmission time data obtained from the transmission time management unit,
A wireless communication system, wherein a terminal that lowers a wireless output level is selected.
(Appendix 12)
In a wireless communication system in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
An error rate management unit for obtaining an error rate when the information is directly transmitted from the peripheral terminal and an error rate when the information is transmitted via the peripheral terminal;
Have
The change terminal determination unit, the reception field level data of the peripheral terminal obtained from the reception field level management unit, the error rate comparison result obtained from the error rate management unit,
A wireless communication system, wherein a terminal that lowers a wireless output level is determined.
(Appendix 13)
In a wireless communication method in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
Comparing received electric field levels of the peripheral terminals;
Determining a terminal that lowers a wireless output level from among the plurality of peripheral terminals;
Obtaining an error rate when the information is directly transmitted from the peripheral terminal and an error rate when the information is transmitted via;
Have
The step of determining the terminal that lowers the radio power level includes a case where data of the received electric field level of the peripheral terminal obtained from the step of comparing the received electric field level of the peripheral terminal and information are directly transmitted from the peripheral terminal The error rate comparison result obtained from the step of obtaining the error rate and the error rate when sent via
A wireless communication method, comprising: determining a terminal that lowers a wireless output level from
(Appendix 14)
In a wireless communication method in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
Comparing received electric field levels of the peripheral terminals;
Determining a terminal that lowers a wireless output level from among the plurality of peripheral terminals;
Calculating a time required for transmission of information transmitted from the peripheral terminal from a transmission time and a reception time of information transmitted from the peripheral terminal;
Have
The step of determining a terminal that lowers the wireless output level selects the peripheral terminal having a plurality of transmission required times of the transmitted information, calculates each difference, and compares it with a predetermined threshold value.
The step of determining the terminal that lowers the radio power level includes the transmission field level data of the peripheral terminal obtained from the step of comparing the reception field level of the peripheral terminal and the transmission requirement of the information transmitted from the peripheral terminal Data of the difference in transmission time obtained from the step of calculating the time from the transmission time and the reception time of the information transmitted from the peripheral terminal;
A wireless communication method characterized by selecting a terminal whose wireless output level is reduced from the above.
(Appendix 15)
The predetermined threshold is:
Hop count data obtained from the hop count management section,
Processing time in the peripheral terminal via, and
15. The wireless communication method according to appendix 14, wherein the wireless communication method is a value obtained from the transmission delay time in the peripheral terminal via the route.

  The present invention is applicable to a wireless communication terminal that can be used in an area where terminals performing wireless communication are dense.

DESCRIPTION OF SYMBOLS 101 Wireless communication terminal 102 Control part 103 Wireless part 104 Peripheral terminal management part 105 Hop number calculation part 106 Memory 107 Communication quality message management part 201 Reception electric field level management part 202 Hop number management part 203 Transmission time management part 204 Error rate management part 205 Changed terminal determination unit

Claims (10)

In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
Said measuring the number of hops from the peripheral terminal, the peripheral terminal that the number of hops there are multiple hops number management unit for determining as said peripheral terminal which duplicate sending the information,
Have
The changed terminal determination unit selects the peripheral terminal having the reception electric field level higher than a set threshold value and transmitting the information redundantly as a terminal for reducing the radio output level. Wireless communication terminal. 2. The wireless communication terminal according to claim 1, wherein the selection is performed when a predetermined amount of the received electric field level data and the hop count data is accumulated or every predetermined time. In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
A transmission time management unit for calculating a transmission time required for said information transmitted from the peripheral terminal and a transmission time and reception time of the information transmitted from the peripheral terminal,
Have
The change terminal determination unit selects the peripheral terminal having a reception electric field level higher than a set threshold value and having a plurality of pieces of data of the required transmission time as a terminal for reducing the radio output level. Communication terminal. In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
An error rate managing unit to obtain an error rate when the information from the peripheral terminal is transmitted via the error rate when the transmitted directly,
Have
The changed terminal determination unit lowers the wireless output level of the peripheral terminal having a reception electric field level higher than a set threshold and an error rate when the direct transmission is performed is higher than an error rate when the transmission is performed via the transmission. wireless communication terminal and judging as the terminal to be. In a wireless communication terminal in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
A transmission time management unit for calculating a transmission time required for said information transmitted from the peripheral terminal and a transmission time and reception time of the information transmitted from the peripheral terminal,
Have
The transmission time management unit compares said transmitted by the transmission required time selects the plurality of the peripheral terminal calculates the respective differences between the predetermined second threshold value of the information,
The changed terminal determination unit selects the peripheral terminal having a reception electric field level higher than a set first threshold and a difference in the required transmission time equal to or less than the second threshold as a terminal for reducing the radio output level. A wireless communication terminal. In a wireless communication system in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
A received electric field level management unit for comparing received electric field levels of the peripheral terminals;
A change terminal determination unit that determines a terminal that lowers the wireless output level from among the plurality of peripheral terminals;
Said measuring the number of hops from the peripheral terminal, the peripheral terminal that the number of hops there are multiple hops number management unit for determining as said peripheral terminal which duplicate sending the information,
Have
The changed terminal determination unit selects the peripheral terminal having the reception electric field level higher than a set threshold value and transmitting the information redundantly as a terminal for reducing the radio output level. Wireless communication system. In a wireless communication method in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
Comparing received electric field levels of the peripheral terminals;
Determining a terminal that lowers a wireless output level from among the plurality of peripheral terminals;
A step wherein the measuring the number of hops from the peripheral terminal, to determine the peripheral terminal that the number of hops there are multiple, as the peripheral terminal that duplicate sending the information,
Have
It said step of determining the terminal to reduce the radio output level, the peripheral terminal that the reception electric field level is high and duplicate the above set threshold is transmitting the information, as a terminal to reduce the radio output level A wireless communication method characterized by screening.   In a wireless communication method in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
  Comparing received electric field levels of the peripheral terminals;
  Determining a terminal that lowers a wireless output level from among the plurality of peripheral terminals;
  Calculating a required transmission time of the information transmitted from the peripheral terminal from a transmission time and a reception time of the information transmitted from the peripheral terminal;
Have
  The step of determining a terminal that lowers the wireless output level selects the peripheral terminal that has a reception electric field level higher than a set threshold value and has a plurality of data for the required transmission time as a terminal that reduces the wireless output level. And a wireless communication method.   In a wireless communication method in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
  Comparing received electric field levels of the peripheral terminals;
  Determining a terminal that lowers a wireless output level from among the plurality of peripheral terminals;
  Obtaining an error rate when the information is directly transmitted from the peripheral terminal and an error rate when the information is transmitted via;
Have
  The step of determining a terminal that lowers the wireless output level includes determining the peripheral terminal that has a received electric field level higher than a set threshold and an error rate when directly transmitted is higher than an error rate when transmitted via the And determining as a terminal that lowers the wireless output level.   In a wireless communication method in which any one terminal receives information from a plurality of peripheral terminals located in the vicinity thereof,
  Comparing received electric field levels of the peripheral terminals;
  Determining a terminal that lowers a wireless output level from among the plurality of peripheral terminals;
  Calculating a required transmission time of the information transmitted from the peripheral terminal from a transmission time and a reception time of the information transmitted from the peripheral terminal;
Have
  The step of calculating the required transmission time selects the peripheral terminal having a plurality of the required transmission times of the information to be transmitted, calculates each difference, and compares it with a predetermined second threshold,
  The step of determining a terminal that lowers the wireless output level includes the step of determining the wireless terminal that has a reception electric field level higher than a set first threshold and whose difference in required transmission time is less than or equal to the second threshold. A wireless communication method characterized by selecting as a terminal for lowering a level.

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