JP6191117B2 - Wireless communication apparatus, wireless communication system, wireless communication method, and program - Google Patents

Description

  The present invention relates to a wireless communication device, a wireless communication system, a wireless communication method, and a program.

  When data is transmitted via a communication network, if a plurality of data are transmitted at the same time, a collision may occur and data transmission may fail. In this case, data that failed to be transmitted is retransmitted, resulting in a data delay, a decrease in communication efficiency, and an increase in power consumption.

  On the other hand, Patent Literature 1 and Patent Literature 2 disclose techniques for reducing the influence of collision by adjusting the timing of transmitting data.

  Specifically, in Patent Document 1, the parent device divides a start signal for notifying the child device of the presence of the parent device, and sequentially transmits the plurality of divided start signals to the child device at intervals. A meter reading data collection system is disclosed.

  In Patent Document 2, each terminal that transmits meter reading data and general-purpose data other than meter reading data using multi-hop wireless communication limits the number of frames transmitted at one time when transmitting meter reading data. In addition, a meter reading data collection system is disclosed in which when the amount of meter reading data exceeds a predetermined number of frames, transmission is stopped for a certain period of time, and then the remaining meter reading data is transmitted.

  As described above, in the techniques disclosed in Patent Document 1 and Patent Document 2, since data transmitted by a specific device is distributed and transmitted, it is possible to reduce a delay time when a collision occurs. .

JP2012-015879A JP 2011-082672 A

  However, in the techniques described in Patent Literature 1 and Patent Literature 2, since the master unit and each terminal independently determine the transmission timing without considering the data transmission timing in other terminals, Collisions may occur due to overlapping of data transmission timings in the terminal. For this reason, there is a case where the possibility of occurrence of collision cannot be reduced.

  Specifically, in the technique described in Patent Document 1, the transmission interval between data transmitted by one terminal is adjusted, but the transmission interval between data transmitted by a plurality of terminals is not adjusted. In addition, since the technology described in Patent Document 2 is based on a system that transmits data by multi-hop wireless communication, it is considered that a collision occurs when a plurality of terminals transmit data to the same base station. It has not been.

  The objective of this invention is providing the radio | wireless communication apparatus, the radio | wireless communications system, the radio | wireless communication method, and program which can reduce possibility that a collision will generate | occur | produce.

  The wireless communication device according to the present invention includes a communication unit connected to a plurality of terminals, a detection unit that detects the terminal connected to the communication unit, and a number of the terminals detected by the detection unit. A timing determination unit that determines a transmission timing at which the terminal transmits data; and a timing instruction unit that transmits a transmission instruction to the terminals to transmit data at the transmission timing determined by the timing determination unit.

  A wireless communication system according to the present invention includes a plurality of terminals and a wireless communication device connected to the plurality of terminals. The wireless communication device includes a communication unit connected to the plurality of terminals, and the communication unit includes: The detection unit that detects the connected terminal, the timing determination unit that determines the transmission timing at which each terminal transmits data based on the number of the terminals detected by the detection unit, and the timing determination unit A timing instruction unit that transmits a transmission instruction to the terminals to transmit data at the transmission timing.

  A wireless communication method according to the present invention detects a plurality of terminals connected to a wireless communication device, determines a transmission timing at which each terminal transmits data based on the detected number of terminals, and determines the determined transmission timing A transmission instruction to transmit data is transmitted to each terminal.

  A program according to the present invention includes a procedure for detecting a plurality of terminals in a computer connected to a plurality of terminals, and a procedure for determining a transmission timing at which each terminal transmits data based on the number of detected terminals. And a procedure for transmitting to each terminal a transmission instruction for transmitting data at the determined transmission timing.

  According to the present invention, it is possible to reduce the possibility of collision.

It is a block diagram of the radio | wireless communications system concerning one Embodiment of this invention. It is explanatory drawing for demonstrating the event which may occur when each meter-reading terminal transmits meter-reading data at random in the radio | wireless communications system of the comparative example of this invention. It is a block diagram of the base station in the radio | wireless communications system of FIG. It is explanatory drawing which shows an example of the method of adjusting the transmission timing of each meter-reading terminal in the radio | wireless communications system of FIG. It is a block diagram of the meter-reading terminal of FIG. 4 is a flowchart for explaining an operation example of the base station of FIG. 3.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification and drawing, the description which overlaps may be abbreviate | omitted by attaching | subjecting the same code | symbol about the component which has the same function.

  FIG. 1 is a configuration diagram of a wireless communication system according to an embodiment of the present invention. A wireless communication system 10 illustrated in FIG. 1 includes a base station 100, a plurality of meter-reading terminals MR, and a plurality of general terminals MS. Hereinafter, the meter-reading terminal MR and the general terminal MS may be collectively referred to as terminals.

  Base station 100 is connected to meter-reading terminal MR and general terminal MS via a wireless communication network (not shown). The base station 100 receives meter reading data from the meter reading terminal MR. The base station 100 receives general-purpose data other than meter-reading data from the general terminal MS.

  The meter-reading terminal MR is an example of a first terminal that transmits meter-reading data to the base station 100 at a predetermined cycle. The meter-reading terminal MR has a measuring instrument, and generates meter-reading data by measuring the meter of the measuring instrument. The meter which the meter-reading terminal MR has measures the usage-amount of electricity, gas, or water, for example. Here, the value indicated by the meter of the measuring instrument is a cumulative value of the amount used. The meter reading data includes this cumulative value and the date and time when the meter is read. The meter-reading terminal MR has a clock for measuring time, generates meter-reading data at a predetermined cycle, and transmits it to the base station 100.

  The general terminal MS is an example of a second terminal that transmits and receives general-purpose data that is data other than meter-reading data to and from the base station 100. The general terminal MS is an information processing apparatus such as a PC (Personal Computer), a mobile phone, or a television receiver. The general terminal MS may be a refrigerator, a microwave oven, an air conditioner or the like equipped with a communication function in addition to the information processing apparatus exemplified above.

  In the wireless communication system 10, when a plurality of terminals access the base station 100 at the same time, a collision between data may occur.

  FIG. 2 is an explanatory diagram for explaining an event that can occur when each meter-reading terminal transmits meter-reading data at random in the wireless communication system of the comparative example of the present invention. FIG. 2 shows the timing at which each meter-reading terminal MR attempts to transmit meter-reading data, the ranging time that is the access timing to the wireless communication network, and the timing at which each meter-reading terminal MR actually transmits the meter-reading data. Yes.

  As shown in FIG. 2, when each meter reading terminal MR transmits meter reading data at random, the transmission timing of meter reading data may be concentrated between the meter reading terminals MR. When the transmission timings of meter reading data are concentrated, the possibility of collision between meter reading data increases, and the possibility of collision between general-purpose data and meter reading data transmitted by a general terminal MS (not shown) increases.

  At this time, the general-purpose data transmitted by the general terminal MS may include data having a high real-time requirement, such as voice data by a call function. When a delay occurs with respect to data having a high real-time requirement, the service quality is significantly lowered. On the other hand, meter reading data is data with low real-time requirements, and even if the data is somewhat delayed, there is often no problem in terms of service quality. Therefore, the base station 100 does not adjust the transmission timing of the general-purpose data transmitted from the general terminal MS, and transmits the transmission timing of the meter-reading data transmitted from the meter-reading terminal MR at intervals between the plurality of meter-reading terminals MR. Adjust to be.

  Next, FIG. 3 is a configuration diagram of the base station 100 according to the present embodiment. The base station 100 illustrated in FIG. 3 includes a wireless communication unit 101, a detection unit 103, a storage unit 102, a transmission timing determination unit 104, and a message generation unit 105.

  The wireless communication unit 101 is connected to a plurality of terminals via a wireless communication network, and transmits and receives data. The wireless communication unit 101 is a communication interface compliant with, for example, WiMAX (Worldwide Interoperability for Microwave Access), which is one of the standards of wireless communication technology. In a communication interface compliant with WiMAX, there is a limit on the number of terminals that can be accessed simultaneously. For this reason, when more than a limited number of terminals simultaneously access the wireless communication unit 101 that is a communication interface compliant with WiMAX, a collision occurs.

  The storage unit 102 stores meter reading terminal information. The meter reading terminal information includes identification information of the meter reading terminal MR connected to the wireless communication unit 101.

  The detection unit 103 detects a terminal to which the wireless communication unit 101 is connected. The detection unit 103 distinguishes whether the connected terminal is the meter reading terminal MR or the general terminal MS based on the identification information transmitted by the meter reading terminal MR and the general terminal MS, for example. The detection unit 103 generates meter reading terminal information including identification information of the meter reading terminal MR among the detected terminals, and stores the information in the storage unit 102. Moreover, the detection part 103 updates the meter-reading terminal information memorize | stored in the memory | storage part 102, whenever meter-reading terminal information is produced | generated.

  The transmission timing determining unit 104 obtains the number of meter reading terminals MR detected by the detecting unit 103 by counting the number of identification information included in the meter reading terminal information stored in the storage unit 102. The transmission timing determination unit 104 determines the timing at which each meter reading terminal MR transmits meter reading data within a predetermined transmission period based on the obtained number of meter reading terminals MR.

  Here, FIG. 4 is an explanatory diagram illustrating a specific example of a method in which the base station 100 of the wireless communication system 10 according to the present embodiment determines the transmission timing of each meter-reading terminal MR. In FIG. 4, it is assumed that meter-reading terminals MR1 to MR7 are connected to the base station 100 as meter-reading terminals MR.

  The transmission timing determination unit 104 determines each transmission timing based on a predetermined transmission period and the counted number of meter-reading terminals MR so that the transmission timings of the meter-reading terminals MR are dispersed within the transmission period.

  Specifically, the transmission timing determination unit 104 obtains a time T obtained by dividing the transmission period by the number of meter-reading terminals MR. During the transmission period, the transmission timing of each meter reading terminal MR is assigned so that each meter reading terminal MR sequentially transmits meter reading data every time T. For example, if the transmission period start time t1 is the transmission timing of the meter reading terminal MR1, the transmission timing determining unit 104 sets the transmission timing of the meter reading terminal MR2 to t1 + T and the transmission timing of the meter reading terminal MR3 to t1 + 2T. The transmission timing is similarly determined for the meter reading terminals MR4 to MR7.

  The transmission timing determination unit 104 determines the transmission timing of each meter reading terminal MR every time the meter reading terminal information stored in the storage unit 102 is updated. Since the meter reading terminal information is updated every time the meter reading terminal MR connected to the wireless communication unit 101 changes, the transmission timing determination unit 104 changes the meter reading terminal MR connected to the wireless communication unit 101. Every time, the transmission timing of each meter-reading terminal MR is determined.

  Returning to the description of FIG. The message generation unit 105 is an example of a timing instruction unit that transmits a transmission instruction for transmitting meter-reading data at the transmission timing determined by the transmission timing determination unit 104 to each terminal. Specifically, the message generation unit 105 generates a transmission instruction message indicating that meter reading data is transmitted at the transmission timing determined by the transmission timing determination unit 104, and transmits the generated transmission instruction message to each meter reading via the wireless communication unit 101. By transmitting to the terminal MR, the transmission timing is instructed to each meter reading terminal MR. Note that the message generation unit 105 may generate a transmission timing instruction message for all meter reading terminals MR, or generates a transmission timing instruction message only when the timing at which each meter reading terminal MR transmits meter reading data is changed. May be.

  Next, FIG. 5 is a configuration diagram of the meter reading terminal according to the present embodiment. The meter-reading terminal MR shown in FIG. 5 includes a measuring instrument 201, a meter-reading data generation unit 202, and a wireless communication unit 203.

  The measuring device 201 measures the accumulated value of usage such as electricity, gas, or water.

  The meter-reading data production | generation part 202 produces | generates the meter-reading data which show the usage-amount by measuring the meter 201. FIG. The meter-reading data generation unit 202 transmits the generated meter-reading data to the base station 100 via the wireless communication unit 203. The meter reading data generation unit 202 reads the meter 201 at a predetermined meter reading interval. Moreover, the meter-reading data production | generation part 202 normally transmits the produced meter-reading data toward the base station 100 regularly with a predetermined period. When the transmission timing instruction message is received from the base station 100, the meter reading data generation unit 202 adjusts the transmission timing according to the transmission timing instruction message and transmits the meter reading data at the transmission timing instructed from the base station 100.

  The wireless communication unit 203 is connected to the base station 100 via a wireless communication network. The wireless communication unit 203 transmits the meter reading data input from the meter reading data generation unit 202 to the base station 100. In addition, the wireless communication unit 203 receives a transmission timing instruction message from the base station 100 and inputs the received transmission timing instruction message to the meter reading data generation unit 202.

  Next, FIG. 6 is a flowchart for explaining an operation example of the base station according to the present embodiment.

  First, the detection unit 103 detects the meter-reading terminal MR connected to the base station 100 (step S100). Then, the detection unit 103 determines whether or not the detected meter reading terminal MR has changed from the previously detected meter reading terminal MR (step S105).

  When the meter-reading terminal MR connected to the base station 100 changes, the detecting unit 103 updates the meter-reading terminal information stored in the storage unit 102 based on the current detection result, and then the meter-reading terminal information is updated. The update completion information indicating that it has been sent is transmitted to the transmission timing determination unit 104 (step S110). On the other hand, when the meter-reading terminal MR connected with the base station 100 does not change, the process returns to step S100.

  Upon receiving the update end information, the transmission timing determination unit 104 counts the identification information of the meter reading terminal MR included in the meter reading terminal information, thereby obtaining the number of meter reading terminals MR connected to the base station 100 (Step S115). ). Then, the transmission timing determination unit 104 determines the transmission timing of each meter reading terminal MR based on the obtained number of meter reading terminals MR (step S120).

  Then, the message generation unit 105 instructs the transmission timing by transmitting a transmission instruction to the effect that the meter reading data is transmitted at the transmission timing determined by the transmission timing determination unit 104 (step S125).

  As described above, according to the present embodiment, the transmission timing at which each terminal transmits data is determined based on the number of terminals connected to the base station 100. As a result, it is possible to suppress overlapping timings at which data is transmitted between a plurality of terminals connected to the base station 100, and thus it is possible to reduce the possibility of collision.

  In addition, by reducing the possibility of collision, the wireless communication system 10 according to the present embodiment can maintain high communication efficiency and reduce power consumption of the meter-reading terminal MR and the general terminal MS. It becomes possible. When collision occurs and data transmission fails, the data that failed to be transmitted is retransmitted. For this reason, when collision occurs, the communication efficiency is reduced, and extra power is consumed when the meter-reading terminal MR and the general terminal MS retransmit data. On the other hand, since the possibility that collision will occur is reduced, the possibility that data is retransmitted is reduced, so that high communication efficiency can be maintained and power consumption can be reduced.

  In the present embodiment, the transmission timings are determined so that the transmission timings of the terminals are dispersed within the transmission period. Thereby, since the timing at which data is transmitted within the transmission period is dispersed, it is possible to more reliably reduce the possibility of collision.

  In the present embodiment, the terminals connected to the base station 100 include a meter-reading terminal MR that transmits meter-reading data generated by meter-reading a meter and a general terminal MS that transmits data other than meter-reading data. The transmission timing is determined based on the number of meter-reading terminals MR among the terminals connected to the base station 100, and the transmission timing is instructed to each meter-reading terminal MR. If the transmission timing of data with a high real-time requirement is adjusted, a delay may occur in the data with a high real-time requirement and the service quality may deteriorate. In this embodiment, the real-time requirement is low. The transmission timing is adjusted only for the meter reading data. Therefore, it is possible to reduce the possibility of collision while suppressing the possibility of lowering the service quality.

  In this embodiment, the transmission timing is determined every time the terminal to which the wireless communication unit 101 is connected changes. As a result, even if a change occurs in the system configuration, it is possible to reliably reduce the possibility of collision.

  While the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

  For example, in the above embodiment, the radio communication system in which the base station 100 is connected to the meter-reading terminal MR and the general terminal MS has been described, but the present invention is not limited to such an example. For example, the present technology can be applied to a wireless communication system that does not include the general terminal MS and includes the meter-reading terminal MR and the base station 100.

  In the above embodiment, the transmission timing of the meter reading terminal MR that transmits meter reading data is adjusted. However, the present invention is not limited to such an example. Similar to the meter reading data, it is possible to adjust the transmission timing by applying the present invention to all data with low real-time requirements.

  Moreover, in the said embodiment, whenever the detection part 103 updates the meter-reading terminal information memorize | stored in the memory | storage part 102, transmission timing determination part 104 transmits meter-reading terminal information by transmitting update completion information to the transmission timing determination part 104. However, the present invention is not limited to such an example. For example, the transmission timing determination unit 104 may periodically detect the meter reading terminal information stored in the storage unit 102 to detect the update of the meter reading terminal information.

  In the above embodiment, the meter reading value, which is the accumulated value of the usage amount, is transmitted as meter reading data, but the present invention is not limited to such an example. For example, the meter reading data may be a usage amount for a specific period obtained from the meter reading value. In this case, the meter-reading data generation unit 202 stores the acquired meter-reading value, and can obtain the usage amount by taking the difference between the previous meter-reading value and the current meter-reading value.

  Moreover, although the said embodiment demonstrated the radio | wireless communications system 10, the apparatus structure of the base station 100 contained in the radio | wireless communications system 10, and the meter-reading terminal MR, and the radio | wireless communication method in the base station 100, the base station 100 and meter-reading terminal were demonstrated. It is also possible to provide a program describing a procedure for realizing the functions of each MR and a recording medium storing the program.

100 Base station (wireless communication device)
101 wireless communication unit 102 storage unit 103 detection unit 104 transmission timing determination unit (timing determination unit)
105 Message generation unit (timing instruction unit)
MR meter reading terminal (first terminal)
201 Meter 202 Meter reading data generation unit 203 Wireless communication unit MS General terminal (second terminal)

Claims (6)

A communication unit connected to a plurality of terminals including a first terminal that transmits meter reading data generated by measuring a meter and a second terminal that transmits data other than the meter reading data;
A detection unit for detecting the terminal to which the communication unit is connected;
A timing determining unit that determines a transmission timing at which each terminal transmits data, based on the number of the terminals detected by the detecting unit;
A timing instruction unit that transmits to each terminal a transmission instruction to transmit data at the transmission timing determined by the timing determination unit,
The timing determination unit determines the transmission timing of each first terminal based on the number of the first terminals among the terminals,
The timing instruction unit transmits to each first terminal a transmission instruction to transmit data at the transmission timing of each first terminal determined by the timing determination unit based on the number of the first terminals. , Wireless communication device.   The wireless communication apparatus according to claim 1, wherein the timing determination unit determines each transmission timing such that transmission timings of the terminals are dispersed within a predetermined transmission period. The wireless communication apparatus according to claim 1, wherein the timing determination unit determines the transmission timing every time the number of terminals connected to the communication unit changes. A plurality of terminals including a first terminal for transmitting meter reading data generated by meter reading a meter and a second terminal for transmitting data other than the meter reading data;
A wireless communication device connected to the plurality of terminals,
The wireless communication device
A communication unit connected to the plurality of terminals;
A detection unit for detecting the terminal to which the communication unit is connected;
A timing determining unit that determines a transmission timing at which each terminal transmits data, based on the number of the terminals detected by the detecting unit;
A timing instruction unit that transmits to each terminal a transmission instruction to transmit data at the transmission timing determined by the timing determination unit;
The timing determination unit determines the transmission timing of each first terminal based on the number of the first terminals among the terminals,
The timing instruction unit transmits to each first terminal a transmission instruction to transmit data at the transmission timing of each first terminal determined by the timing determination unit based on the number of the first terminals. Wireless communication system. Detecting a plurality of terminals connected to a wireless communication device, including a first terminal that transmits meter reading data generated by meter reading a meter and a second terminal that transmits data other than the meter reading data. ,
Based on the number of detected terminals, each terminal determines the transmission timing for transmitting data,
A transmission instruction to transmit data at the determined transmission timing is transmitted to each terminal,
Determining the transmission timing of each first terminal based on the number of the first terminals of the terminals;
A wireless communication method for transmitting to each first terminal a transmission instruction for transmitting data at a transmission timing of each first terminal, determined based on the number of the first terminals. To a computer connected to a plurality of terminals including a first terminal that transmits meter reading data generated by meter reading a meter and a second terminal that transmits data other than the meter reading data,
Detecting the plurality of terminals;
A procedure for determining a transmission timing at which each terminal transmits data based on the number of detected terminals;
A procedure for transmitting to each terminal a transmission instruction to transmit data at the determined transmission timing;
Determining the transmission timing of each first terminal based on the number of the first terminals of the terminals;
A program for executing a procedure for transmitting to each first terminal a transmission instruction for transmitting data at the transmission timing of each first terminal, determined based on the number of the first terminals.

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