JP2020036160A - Radio communication device and radio communication system - Google Patents

Abstract

To provide a radio communication device and a radio communication system that can appropriately receive desired waves even a state where there is a lot of urban noise.SOLUTION: A radio communication device measures a reception electric field strength with a reception electric field strength measuring unit 34, switches between a reception state and a waiting state of a reception unit 32 according to the value of the reception electric field strength with a low power consumption mode setting unit 35, measures a reception electric field strength of urban noise after the measurement of the reception electric field strength when a desired wave is received, and updates a threshold value so as to set the threshold value for switching the reception state between the value of the reception electric field strength and the value of the reception electric field strength of urban noise when the desired wave is received.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wireless communication device that measures a received electric field strength, and more particularly to a wireless communication device and a wireless communication system that reliably start notification according to the level of city noise and determine an optimal installation location.

[Conventional technology]
In a conventional wireless communication device, there has been a device that measures a received electric field intensity, and when a received electric field intensity exceeds a specific threshold, changes a mode of a receiving unit from a low power consumption mode (standby mode) to a receiving mode and starts reporting.

[Wireless communication system: Fig. 5]
A general wireless communication system will be described with reference to FIG. FIG. 5 is a schematic diagram of a wireless communication system.
As shown in FIG. 5, the wireless communication system includes a base station 2, a console 1 connected to the base station 2 by wire, and a plurality of slave stations 3 a and 3 b (hereinafter, slave stations) performing wireless communication with the base station 2. 3 will be described).

Although two slave stations 3 are illustrated in FIG. 5, a plurality of slave stations 3 are installed in a service area where radio waves of the base station 2 reach.
Communication between the base station 2 and the slave station 3 is performed using the frequency a.
Here, a case is shown where the slave station 3 is in an environment affected by radiation noise (urban noise) b from an electronic device 4 installed nearby.

The operation in the wireless communication system of FIG. 5 will be described.
The base station 2 transmits only at the time of reporting, and wirelessly transmits the reporting signal input from the console 1 to the slave station 3.
The slave station 3 internally measures the reception electric field strength and starts the reception operation when the reception electric field strength exceeds a predetermined threshold. When the reception electric strength does not exceed the predetermined threshold, the slave station 3 enters a standby state to reduce power consumption. Thus, the operation time of the battery can be extended.
In other words, when the notification signal is transmitted from the base station 2, the received signal strength exceeds the threshold, and the slave station 3 starts the receiving operation, receives the notification signal, and performs the notification operation.

[Wireless communication device: FIG. 6]
Next, the configuration of the wireless communication device of the slave station 3 in FIG. 5 will be described with reference to FIG. FIG. 6 is a configuration block diagram of a conventional wireless communication device.
As shown in FIG. 6, the wireless communication device includes an antenna 31, a receiving unit 32 ', a control unit 33', a received electric field strength measuring unit 34, and a low power consumption mode setting unit 35 '.

The operation of the wireless communication apparatus is as follows. The antenna 31 receives the frequency a from the base station 2, measures the received field strength by the received field strength measurement unit 34, and sets the measured value of the received field strength to the low power consumption mode setting unit. 35 '.
The low power consumption mode setting unit 35 'determines whether or not the value of the received reception electric field strength exceeds a preset threshold value, and outputs the reception mode signal to the reception unit 32' if it exceeds the threshold value. .
The receiving unit 32 'to which the receiving mode signal has been input starts the receiving operation (receiving mode), performs frequency conversion and demodulation of the signal input from the antenna 31, and sends the received notification signal to the control unit 33'. Output.

The control unit 33 'outputs a notification signal to a speaker to be connected, and outputs a notification signal from the console 1 by voice.
When the notification ends, the control unit 33 'outputs a notification end signal to the low power consumption mode setting unit 35'.
The low-power-consumption mode setting unit 35 ', which has received the notification end signal, outputs a standby mode signal to the receiving unit 32' to put the receiving unit 32 'in a standby state (standby mode).

[Related technology]
As a related prior art, there is Japanese Patent Application Laid-Open No. 2006-197364 “Receiver of Wireless Communication System” (Patent Document 1).
Patent Document 1 discloses that in a receiver of a wireless communication system, a reception electric field strength measurement unit measures a reception electric field strength of a signal received by a reception antenna, and a low power consumption mode setting unit sets a reception start threshold measured as a reception start threshold. This indicates that the reception operation is performed when the received electric field intensity is equal to or greater than the threshold value.

JP 2006-197364 A

  However, in a wireless communication device (receiver) in a conventional wireless communication system, if the city noise exceeds a threshold value of the received electric field strength when installed in an environment with high city noise, the receiving unit remains in the reception mode. Therefore, there is a problem that the standby mode is not set, and the power consumption cannot be suppressed.

  Specifically, when the wireless communication device of the slave station 3 of FIG. 5 is installed in an environment with high city noise, the city noise may become higher than the threshold of the reception electric field strength at which the reception operation starts, and if so, the reception operation may be stopped. (Reception mode). Therefore, the wireless communication device (slave station) cannot repeat the receiving operation and switch to the standby state in which power consumption is suppressed.

  For example, assuming that the threshold of the reception electric field strength at the start of reception set in the slave station is -110 dBm, the reception electric field strength of the notification signal received from the base station 2 is -80 dBm, and the reception electric field strength of the city noise is -100 dBm Since the received electric field intensity of the city noise is higher than the received electric field intensity at the start of reception, the receiving operation including the signal processing with a high load is continued, and the power consumption is not reduced.

  There is also a method in which a worker individually sets the threshold value of the reception electric field strength at the start of reception in a place where a slave station is installed, according to the environment of the installation place, but the setting operation becomes complicated and it is difficult to realize. ing.

  Further, in an area of the wireless communication system, an environment where city noise is high is also assumed. If the level difference between the desired signal of the report signal from the base station and the city noise is not sufficiently wide, it is impossible to receive the signal properly, so set up a slave station in an environment where city noise is high and stable reception is possible. There is a need to.

In general, during the construction period for installing a slave station, a test broadcast from the base station is constantly reported, and the location of the slave station is determined using the reception electric field strength of a desired signal and a bit error rate (BER). Often decide.
However, even in an installation location where the received electric field strength of the desired wave from the base station is sufficiently high, the BER is not stable in an environment with high urban noise.

  Originally, it is necessary to measure the city noise while the base station is not reporting to determine the level difference from the received electric field strength of the desired wave.However, due to the efficiency of installing the slave station, the reporting from the base station is required. It is difficult to stop each time.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wireless communication device and a wireless communication system that can properly receive a desired wave even in a state with a lot of city noise.

  Another object of the present invention is to provide a wireless communication device and a wireless communication system that can easily and properly install a wireless communication device of a slave station even in an environment with a lot of city noise.

  The present invention for solving the problems of the above conventional example is a wireless communication device that performs an operation of measuring a reception electric field strength and switching between a reception state and a standby state according to the value of the reception electric field strength, and switching to a reception state. The threshold value is stored, the received electric field strength when the desired wave is received and the received electric field strength of the city noise are measured, and the value of the received electric field strength and the received electric field strength of the city noise when the desired wave is received are measured. It is characterized in that the threshold value is updated so as to be between the values.

  According to the present invention, in the wireless communication apparatus, the value of the received field strength of city noise is measured and stored for a specific period, and the average value of the received field strength of city noise and the desired wave are received during the specific period. It is characterized in that the threshold value is updated so as to be between the value of the received electric field strength in the case.

  The present invention is a wireless communication device that measures a reception electric field strength and performs an operation of switching between a reception state and a standby state according to the value of the reception electric field strength. Measure the received field strength of each city noise in the frequency band, average the measured values of the received field strength to obtain the value of the received field strength of the surrounding city noise, and receive the desired field strength when receiving the desired wave And a notification of a sound or a display is performed based on the difference between the value of the received signal and the value of the received electric field strength of the surrounding city noise.

  The present invention provides a wireless communication system, comprising: the wireless communication device; and a base station that transmits a report signal to the wireless communication device.

  According to the present invention, the reception electric field strength is measured, the operation of switching between the reception state and the standby state is performed according to the value of the reception electric field strength, the threshold for switching to the reception state is stored, and the desired wave is received. Radio that measures the received electric field strength of urban noise and the received electric field strength of city noise, and updates the threshold value so that it is between the value of the received electric field strength when receiving the desired wave and the value of the received electric field strength of city noise. Since the communication device is used, there is an effect that a desired wave can be properly received even in a state where there is much city noise.

  According to the present invention, the reception electric field strength is measured, and the operation of switching between the reception state and the standby state is performed according to the value of the reception electric field strength. Measure the received field strength of each city noise in the band, average the measured value of the received field strength to obtain the value of the received field strength of the surrounding city noise, and obtain the value of the received field strength when the desired wave is received. The wireless communication device performs sound or display notification based on the difference between the value and the value of the received electric field strength of the surrounding city noise, so that this device can be installed easily and properly even in an environment with a lot of city noise. There is.

FIG. 2 is a configuration block diagram of the wireless communication device. FIG. 3 is a configuration block diagram of a low power consumption mode setting unit. FIG. 14 is a flowchart of a reception field intensity threshold update process at the start of reception. It is a processing flow figure of this device installation. 1 is a schematic diagram of a wireless communication system. FIG. 10 is a configuration block diagram of a conventional wireless communication device.

An embodiment of the present invention will be described with reference to the drawings.
[Summary of Embodiment]
The wireless communication device (this device) according to the embodiment of the present invention measures the reception electric field strength, and performs an operation of switching between a reception state and a standby state according to the value of the reception electric field strength. Measure the received field strength of the city noise after the report, and measure the received field strength of the city noise between the value of the received field strength when the desired wave is received and the value of the received field strength of the city noise. Since the threshold is updated so as to set the threshold for switching to the reception state, the desired wave can be properly received even in a state where there is a lot of urban noise.

  Further, the present apparatus measures the received electric field strength, and performs an operation of switching between the reception state and the standby state according to the value of the received electric field strength. When the report is completed in the reception state, the frequency before and after the frequency of the desired wave is measured. Measure the received field strength of each city noise in the band, average the measured value of the received field strength to obtain the value of the received field strength of the surrounding city noise, and obtain the value of the received field strength when the desired wave is received. Since the sound or the display is notified based on the difference between the value and the value of the received electric field strength of the surrounding city noise, the present device can be easily and appropriately installed even in an environment with a lot of city noise. .

  The wireless communication system (the present system) includes the above wireless communication device and a base station that wirelessly transmits a report signal from the command console to the wireless communication device. It can be easily and properly installed, and can properly receive a desired wave even in a state with a lot of urban noise.

[This device: Fig. 1]
This device (this wireless communication device) will be described with reference to FIG. FIG. 1 is a configuration block diagram of the wireless communication device.
As shown in FIG. 1, the present device includes an antenna 31, a receiving unit 32, a control unit 33, a received electric field strength measuring unit 34, a low power consumption mode setting unit 35, a display unit 36, a speaker 37, Basically.
In comparison with FIG. 6, the receiving unit 32, the control unit 33, and the low power consumption mode setting unit 35 are different from the conventional configuration.

[Each part of this device]
Each part of the present apparatus will be specifically described.
The antenna 31 captures an incoming radio signal. The radio signal input to the antenna 31 includes a notification signal from a base station, and also receives urban noise from surroundings.
The receiving unit 32 enters a reception state (reception mode) with a reception mode signal from the low power consumption mode setting unit 35, and stands by (standby mode / low power consumption mode) with a standby mode signal from the low power consumption mode setting unit 35. The frequency of the signal input from the antenna 31 is converted, demodulated, and a notification signal is output to the control unit 33.
The receiving unit 32 is in the receiving state at the time of the notification operation, and returns to the standby state after the notification is completed, thereby realizing power saving.

The control unit 33 outputs the notification signal input from the receiving unit 32 to the connected speaker 37 as a sound.
Further, when the notification ends, the control unit 33 outputs a notification end signal to the low power consumption mode setting unit 35.
Further, as described later, when installing the present apparatus, the control unit 33 outputs the suitability of the installation location to the display unit 36 and / or the speaker 37. This operation will be described later.

The reception electric field strength measurement unit 34 measures the reception electric field intensity of the signal input from the antenna 31 and outputs the measured value to the low power consumption mode setting unit 35.
The measured received electric field strength is a desired signal and a city noise. The “reception electric field strength of a desired wave” described below is the reception electric field strength of a signal in which a desired wave and city noise are combined.

  When the measured value exceeds the reception electric field strength threshold at the start of reception, the low power consumption mode setting unit 35 outputs a reception mode signal to the reception unit 32, and receives a notification end signal from the control unit 33. , And outputs a standby mode signal to the receiving unit 32.

The low-power-consumption mode setting unit 35 stores the measured value of the received electric field intensity of the desired wave and the measured value of the received electric field intensity of the urban noise, and sets a threshold value of the received electric field intensity at the start of reception between the measured values. The threshold value is updated by adjusting the threshold value to be included.
The configuration of the low power consumption mode setting unit 35 and the process of updating the threshold will be described later.

The display unit 36 displays whether or not the location is appropriate in an environment of urban noise when installing the present apparatus described later.
In addition, the display unit 36 may perform a display indicating that a notification is being made.
The speaker 37 outputs an audio signal of the notification.
Further, the speaker 37 is used for notifying by sound whether or not the location is appropriate in an environment of urban noise when installing the present apparatus described later.

[Low power consumption mode setting section: Fig. 2]
Next, the low power consumption mode setting unit 35 will be specifically described with reference to FIG. FIG. 2 is a configuration block diagram of the low power consumption mode setting unit.
As shown in FIG. 2, the low power consumption mode setting unit 35 includes a reception electric field intensity storage / comparison unit 351, a reception electric field intensity threshold storage unit 352 for starting reception, a reception electric field intensity storage unit 353 for a desired wave, and a city. And a noise reception electric field strength storage unit 354.

  The reception electric field strength storage / comparison section 351 receives the value (measurement value) measured by the reception electric field strength measurement section 34 and receives a threshold value (the reception start reception amount) stored in advance in the reception electric field strength threshold storage section 352 of the reception start. If the measured value exceeds the threshold value (or the measured value is equal to or greater than the threshold value), a reception mode signal is output to the reception unit 32 and a notification end signal is input from the control unit 33. Then, a standby mode signal is output to the receiving unit 32, and subsequently, the value of the received electric field intensity of the city noise is input from the received electric field strength measuring unit 34, and the value of the received electric field intensity of the city noise is stored.

  When the measured value includes the desired wave (actually, the desired wave and the city noise are combined), the received electric field strength storage / comparing unit 351 stores the measured value in the received electric field strength storage unit 353 of the desired wave and stores the measured value. Is the city noise, the received field strength storage unit 354 for the city noise is stored. Note that the value of the reception electric field strength of the desired wave (actually, the reception electric field strength in which the desired wave and the city noise are combined) may be set to a fixed value so as not to be updated.

  Further, the reception electric field strength storage / comparison section 351 is provided, when the present apparatus is installed, when the difference between the value of the reception electric field strength of the desired wave and the value of the reception electric field strength of the city noise is equal to or more than a specific value, A notification signal indicating that the installation is appropriate. This installation process will be described later.

  The reception electric field intensity threshold storage unit 352 at the start of reception stores a threshold value of the reception electric field intensity at the start of reception, and the initial value at the time of shipment is preset from the outside. It is updated based on the relationship between the value of the received electric field strength and the value of the received electric field strength of the city noise.

  The reception electric field strength storage unit 353 of the desired wave stores the value of the reception electric field strength of the desired wave. When the value of the reception electric field strength of the desired wave fluctuates, the value may be updated every time the desired wave is received, or the value of the reception electric field strength of the desired wave may be stored for a specific period and updated with the average value. You may memorize it.

  The city noise reception field strength storage unit 354 stores a measurement value of the city noise reception field strength. In this device, the received electric field strength of the city noise is measured after the report is completed, and the measured value is updated and stored. Further, a plurality of values of the received electric field strength of the city noise measured over a specific period may be accumulated, and may be updated with an average value and stored.

[Threshold update processing: FIG. 3]
Next, a process of updating the threshold value of the reception electric field strength at the start of reception will be described with reference to FIG. FIG. 3 is a flowchart of a process for updating the threshold value of the reception electric field strength at the start of reception.
As shown in FIG. 3, the reception electric field intensity is measured by the reception electric field strength measurement unit 34, and when it is determined that the reception electric field intensity threshold value of the reception start is exceeded by the low power consumption mode setting unit 35, the reception mode is transmitted to the reception unit 32. A signal is output, and the receiving operation is started by the receiving unit 32 to start the notification (S1).
Then, the reception electric field intensity of the desired wave is measured by the reception electric field intensity measurement unit 34, and the measured value of the reception electric field intensity of the desired wave is output to the low power consumption mode setting unit 35 and stored (S2).

Then, when the reception end is received by the reception unit 32 and output to the control unit 33, the control unit 33 outputs a notification end signal to the low power consumption mode setting unit 35 (S3).
The low-power-consumption mode setting unit 35 that has received the notification end signal outputs a standby mode signal to the receiving unit 32 to put the receiving unit 32 in a standby state.
Subsequently, the received electric field intensity of the city noise (noise) is measured by the received electric field intensity measuring unit 34, and the measured value of the received electric field intensity of the city noise is output to the low power consumption mode setting unit 35 and stored (S4). .

  Then, the low power consumption mode setting unit 35 compares the measured value of the received electric field intensity of the desired wave with the value of the received electric field intensity of the city noise (S5), and the reception electric field intensity threshold at the start of reception is determined between the two. The threshold value is updated by adjusting the threshold value so as to be included (S6). Thereafter, reception start is determined using the updated threshold.

  The adjustment of the threshold value may be an intermediate value between the measured value of the received electric field intensity of the desired wave and the value of the received electric field intensity of the city noise, or from the intermediate value, for example, 20% closer to the value of the received electric field intensity of the desired wave. May be set as follows.

  If the value of the received electric field strength of the city noise does not affect the threshold, the threshold may not be updated. In addition, even when the value of the received electric field strength of the city noise affects the threshold, if the value is sudden, it may be excluded from updating.

  For example, assuming that the reception electric field strength threshold at the start of reception set in the low power consumption mode setting unit 35 of the slave station at the time of shipment is -110 dBm, the value of the reception electric field strength of the desired wave in the installed environment is -80 dBm. Yes, if the value of the received field strength of the city noise measured after the end of the report is -100 dBm, after receiving the report once, the threshold of the received field strength to determine the start of reception between the desired wave and the city noise, for example , Is updated to the intermediate value of -90 dBm.

  By updating the threshold for judging the start of reception in accordance with the environment in which this device is installed, based on the measured value of the received electric field intensity of the desired wave and the value of the received electric field intensity of the city noise, there is much urban noise. Since it can be determined that there is no report even under the environment, the receiving unit 32 does not perform a high-load signal processing, and the power consumption can be suppressed in the standby state.

[Installation process of this device: Fig. 4]
The installation process of the present apparatus will be described with reference to FIG. FIG. 4 is a processing flowchart of the installation of the present apparatus.
During the construction period for installing this apparatus, a test broadcast is constantly transmitted from the base station, and the installation location is searched using the received electric field strength value and the BER value.
When the operation of the installation mode in which the apparatus is installed is started (S11), the reception electric field intensity of the desired wave being test broadcast is measured by the reception electric field intensity measurement unit 34 of the apparatus, and the measured value is set to the low power consumption mode. It is stored in the unit 35 (S12).

Next, the channel (CH) is switched to a band different from the desired wave, for example, a band below (previous / low frequency side) the desired wave (S13). The intensity is measured, and the measured value is stored in the low power consumption mode setting unit 35 (S14).
Further, the channel is switched to another band, for example, a band on the upper side (after / high frequency side) of the desired wave (S15), and the reception electric field intensity of the noise is measured by the reception electric field intensity measuring section 34, and the measured value is used as the low power consumption. It is stored in the mode setting unit 35 (S16).

In the CH switching, the frequency channel setting is shifted by about several tens of kHz to several hundreds of kHz, and the value of the received electric field strength of the city noise of the frequency near the desired wave is measured.
Here, it is desirable to measure the received electric field strength of the noise in the frequency bands before and after the desired wave, and the received electric field strength of the noise may be measured by switching a plurality of CHs in a wider band.
Note that the reason why the reception electric field strength of the noise is not measured in the band of the desired wave is that the reception electric field strength of the noise cannot be measured because the desired wave is always broadcast.

  Then, the low power consumption mode setting unit 35 averages the noise level (the measured value of the received electric field strength of the noise) (S17), and compares the average value with the measured value of the received electric field strength of the desired wave (S18). , And calculates the difference (level difference) between them, and outputs the numerical value of the level difference to the control unit 33 as a notification signal.

Then, the control unit 33 displays the numerical value of the level difference on the display unit 36 or the speaker 37 based on the notification signal or notifies the speaker 37 by voice. A worker who installs this apparatus can search for an optimum installation place by a notice indicating that there is a sufficient level difference.
Here, the control unit 33 determines whether or not the numerical value of the level difference is equal to or more than a specific value (threshold). If the numerical value is equal to or more than the specific value, the control unit 33 blinks an LED on the display unit 36, sounds a sound from the speaker 37, and the like. May be performed.
The notification may indicate that the level difference is not sufficient. In this case, it indicates that the installation location where the notification is made is not appropriate.

Then, the threshold update process of FIG. 3 and the installation process of FIG. 4 may be performed by one wireless communication device.
Further, the installation mode in FIG. 4 may be set by a switch or the like of the present apparatus, and the installation process of FIG. 4 may be executed by turning on the switch during the installation work of the present apparatus.

[Effects of Embodiment]
According to the present apparatus and the present system, the reception electric field intensity is measured by the reception electric field intensity measurement unit 34, and the reception state and the standby state are set by the low power consumption mode setting unit 35 to the reception unit 32 according to the value of the reception electric field intensity. After performing the switching operation, measure the received field strength of the city noise after measuring the received field strength when the desired wave is received, the value of the received field strength when receiving the desired wave and the received field strength of the city noise. The threshold value is updated so that the threshold value for switching to the reception state is set between the intensity value and the reception value, and there is an effect that the desired wave can be properly received even in a state where there is much urban noise.

  Further, according to the present apparatus and the present system, the reception electric field strength is measured by the reception electric field strength measurement unit 34, and the reception state and the standby state are set to the reception unit 32 by the low electric power consumption mode setting unit 35 according to the value of the reception electric field intensity. When the notification is completed in the reception state, the reception electric field intensity measurement unit 34 measures the reception electric field intensity of each city noise in the frequency band before and after the frequency of the desired wave, and sets the low power consumption mode setting unit. The value of the received field strength measured by 35 is averaged to obtain the value of the received field strength of the surrounding city noise, and the value of the received field strength when the desired wave is received and the value of the received field strength of the surrounding city noise are received. The notification of the sound or the display is performed based on the difference from the above, so that the present apparatus can be easily and appropriately installed even in an environment with much urban noise.

  INDUSTRIAL APPLICABILITY The present invention is suitable for a wireless communication device and a wireless communication system that can properly receive a desired wave even in a state with a lot of city noise.

  DESCRIPTION OF SYMBOLS 1 ... Operation console, 2 ... Base station, 3 ... Child station (wireless communication apparatus), 4 ... Electronic equipment, 31 ... Antenna, 32, 32 '... Receiving part, 33, 33' ... Control part, 34 ... Received electric field strength Measurement unit, 35, 35 ': low power consumption mode setting unit, 36: display unit, 37: speaker, 351: reception electric field intensity storage / comparison unit, 352: reception electric field intensity threshold storage unit for starting reception, 353: desired wave 354: Received electric field strength storage unit for urban noise

Claims (5)

A wireless communication device that measures a reception field strength and performs an operation of switching between a reception state and a standby state according to the value of the reception field strength,
The threshold for switching to the reception state is stored, the reception electric field strength when a desired wave is received and the reception electric field strength of city noise are measured, and the value of the reception electric field strength when the desired wave is received and the A wireless communication apparatus, wherein the threshold value is updated so as to be between the value of the received field strength of city noise.   Measures and stores the value of the received field strength of the city noise for a specific period, and stores the value between the average value of the received field strength of the city noise and the value of the received field strength when a desired wave is received during the specified period. The wireless communication device according to claim 1, wherein the threshold value is updated so that A wireless communication device that measures a reception field strength and performs an operation of switching between a reception state and a standby state according to the value of the reception field strength,
When the report is completed in the reception state, the reception field strength of each city noise in the frequency band before and after the frequency of the desired wave is measured, and the measured reception field strength values are averaged to obtain the reception field strength of the surrounding city noise. A sound or display notification based on the difference between the value of the received electric field strength when the desired wave is received and the value of the received electric field strength of the surrounding urban noise. Communication device.   A wireless communication system, comprising: the wireless communication device according to claim 1; and a base station that transmits a notification signal to the wireless communication device.   A wireless communication system comprising: the wireless communication device according to claim 3; and a base station that transmits a notification signal to the wireless communication device.

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