JP2009033363A - Radio communication system, radio terminal, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system capable of limiting communication in accordance with a speech communication state between slave units. <P>SOLUTION: A master unit 100 includes a plurality of master unit side receiving parts for respectively receiving voice signals modulated in a plurality of frequencies, and a master side transmitting part for modulating voice signals received by the plurality of master side receiving parts in a single frequency and sending the modulated signal. The optional number of slave units 200 includes a slave unit side receiving part for receiving a voice signal transmitted from the master unit 100, a frequency control part for setting a transmission frequency from a plurality of frequencies, and a slave unit side transmitting part for modulating a voice signal to be transmitted to the master unit 100 in the frequency set by the frequency control part and transmitting the voice signal. The master unit 100 detects information about a free frequency among a plurality of frequencies from a using state of the master unit side receiving parts, and always generates a tone signal corresponding to the information. The slave unit 200 limits communication on the basis of the tone signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a wireless communication system, such as an MCA (Multi Channel Access) wireless system, which includes a single parent device and a plurality of child devices, and enables simultaneous calls between the child devices via the parent device, Regarding the program.

  A master unit employed in this type of wireless communication system includes a plurality of receiving circuits and one transmitting circuit, and the plurality of receiving circuits receive signals of different frequencies. On the other hand, each slave unit includes one reception circuit and a transmission circuit capable of transmitting at a plurality of frequencies.

The frequency that can be demodulated by the reception circuit of each slave unit is the transmission frequency of the transmission circuit of the master unit. The frequency that can be transmitted by the transmission circuit of the slave unit is a frequency that can be received by each reception circuit of the master unit.
A plurality of slave units transmit audio signals at different frequencies to the master unit, and the master unit that receives the audio signals from the plurality of slave units mixes the plurality of audio signals and transmits at a single transmission frequency. . Since the master unit always relays and transmits the audio signals from the plurality of slave units, and the plurality of slave units always receive the audio signal transmitted by the master unit, simultaneous communication between the plurality of slave units is possible.

  In order to perform a simultaneous call without any hindrance in this type of wireless communication system, it is necessary to prevent the transmission frequencies used by each slave unit from overlapping. In order to solve this problem, there has been proposed a wireless communication system that transmits the usage status of each receiving unit of the parent device as empty channel information from the parent device to the child device (Patent Document 1).

On the other hand, when a predetermined signal is included in the received signal, a wireless communication system that performs alarm control or transmission stop control for the slave unit to stop signal transmission has been proposed (Patent Document 2). .
JP-A-9-84098 JP-A-11-88224

When the technique described in Patent Document 2 is applied to the wireless communication system described in Patent Document 1, the slave unit that has transmitted the predetermined signal can perform communication preferentially.
However, since the communication of the slave unit cannot be restricted depending on the usage status of each receiving unit of the master unit, it is very inefficient in operating the system.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wireless communication system, a wireless terminal, and a program for restricting transmission of a child device according to the situation of the parent device.

In order to achieve the above object, a wireless communication system according to a first aspect of the present invention includes:
Each of the modulated signals modulated at different n-channel frequencies is received and demodulated, and the n parent device side receiving units that respectively generate the demodulated signals, and the demodulation generated by the n parent device side receiving units. A master unit including a mixing unit that mixes signals, a master unit side transmission unit that modulates and transmits a demodulated signal mixed by the mixing unit at a single frequency, and
Receives and demodulates the modulated signal transmitted from the master unit, generates a demodulated signal, a slave unit side receiver, an output unit that outputs the demodulated signal generated by the slave unit side receiver, and the frequency of the n channel A wireless communication system comprising: a frequency control unit that sets a transmission frequency from the mobile station; and an arbitrary number of slave units including a slave unit side transmission unit that transmits a modulated signal modulated at a frequency set by the frequency control unit to the master unit Because
The base unit is
Information detecting means for detecting information indicating a vacant frequency among the frequencies of the n channels from the usage status of the base-side receiving unit;
Tone signal generating means for constantly generating a tone signal corresponding to information relating to an empty frequency among the frequencies of the n channels detected by the information detecting means,
The slave is
Table storage means for storing a table associating the tone signal with whether or not the modulated signal can be transmitted;
Tone signal receiving means for receiving the tone signal generated by the tone signal generating means;
Control means for controlling whether or not to transmit the modulated signal to the slave unit side transmission unit based on the tone signal received by the tone signal receiving means and the table stored in the table storage means;
It is characterized by providing.

For example, the control means includes
When the tone signal received by the tone signal receiving means indicates that all frequencies of the n channel frequencies are in use, control is performed so as not to transmit the modulated signal by the slave unit side transmission unit. May be.

For example, the control means includes
Control is performed so that the slave unit transmitting unit does not transmit the modulated signal when the tone signal received by the tone signal receiving means indicates that a predetermined number of frequencies of the n channel frequencies are in use. May be.

A wireless terminal according to a second aspect of the present invention is:
Each of the modulated signals modulated at different n-channel frequencies is received and demodulated, and the n parent device side receiving units that respectively generate the demodulated signals, and the demodulation generated by the n parent device side receiving units. Receiving a modulated signal transmitted from a master unit having a mixing unit for mixing signals, and a master-side transmitting unit for transmitting a modulated signal by modulating a demodulated signal mixed by the mixing unit at a single frequency A modulated signal receiving unit that generates a demodulated signal, an output unit that outputs a demodulated signal generated by the modulated signal receiving unit, a frequency control unit that sets a transmission frequency from the n-channel frequency, and the frequency A wireless terminal including a modulated signal transmitting unit that transmits a modulated signal modulated at a frequency set by a control unit to the master unit,
Tone signal receiving means for receiving a tone signal corresponding to information indicating an idle frequency among the frequencies of the n channels from the base unit;
Table storage means for storing a table associating the tone signal with whether or not the modulated signal can be transmitted;
Control means for controlling whether or not to send the modulated signal to the modulated signal transmitter based on the tone signal received by the tone signal receiving means and the table stored in the table storage means;
It is characterized by providing.

The program according to the third aspect of the present invention is:
Receiving and demodulating modulated signals modulated with different n-channel frequencies, respectively, n master unit receiving units for generating demodulated signals, and demodulated signals generated by the n master unit receiving units Receiving a modulated signal transmitted from a base unit having a base unit side transmission unit that modulates a demodulated signal mixed by the mixing unit with a single frequency and transmits the modulated signal. A modulated signal receiving unit that demodulates and generates a demodulated signal, an output unit that outputs a demodulated signal generated by the modulated signal receiving unit, a frequency control unit that sets a transmission frequency from the frequency of the n channel, and the frequency control A computer including a modulated signal transmitting unit that transmits a modulated signal modulated at a frequency set by the unit to the master unit;
A table storage means for storing a table in which a tone signal corresponding to information indicating an empty frequency among the frequencies of the n channels of the base-side receiving unit is associated with whether or not a modulated signal can be transmitted;
Based on the tone signal received from the base unit by the modulated signal receiving unit and the table stored in the table storage unit, the modulated signal transmitting unit controls whether or not to transmit the modulated signal. Control means,
It is made to function as.

  ADVANTAGE OF THE INVENTION According to this invention, transmission of a subunit | mobile_unit can be restrict | limited according to the condition of a main | base station in the radio | wireless communications system comprised from a subunit | mobile_unit and a main | base station.

  Hereinafter, a wireless communication system 1000 according to an embodiment of the present invention will be described. The wireless communication system 1000 enables a call between a plurality of slave units via the master unit.

  As shown in FIG. 1, the wireless communication system 1000 includes a single parent device 100 and a plurality of child devices 200.

  As shown in FIG. 2, the base unit 100 includes a receiving antenna 101 and, for example, four first receiving units 111, a second receiving unit 112, which are the base unit side receiving units connected to the receiving antenna 101, Third receiving unit 113 and fourth receiving unit 114, audio mixing unit 115, control unit 116, tone signal generating unit 117, squelch circuit 118, speaker 119, and PTT (Push to Talk) switch ( PTT) 120, a microphone 121, a transmitter 122 that is a transmitter side transmitter, a transmission antenna 123, and a memory 124.

  The receiving units 111 to 114 are connected to the receiving antenna 101 and, in an active state, demodulate modulated signals of different frequencies F1, F2, F3, and F4, respectively, and extract audio signals. These frequencies F1, F2, F3, and F4 correspond to the transmission frequency of handset 200, as will be described later, and “1”, “2”, “3”, and “4” attached to each frequency F1, F2, F3, and F4. The number “4” indicates the priority when selecting / designating the frequency.

  The audio mixing unit 115 is connected to the receiving units 111 to 114 and mixes audio signals given from the receiving units 111 to 114. The output side of the audio mixing unit 115 is connected to the transmission unit 122 and is also connected to the speaker 119 via the squelch circuit 118. Opening and closing of the squelch circuit 118 is controlled by the control unit 116. The speaker 119 outputs the audio signal given from the audio mixing unit 115 as audio.

  The control unit 116 is composed of, for example, a CPU (Central Processing Unit) and the like, and controls the entire parent device 100.

When the control unit 116 detects that the PTT switch 120 is pressed, the control unit 116 outputs the audio signal input from the microphone 121 to the transmission unit 122.
When the control unit 116 detects that a plurality of reception units are in an empty state, the control unit 116 selects a frequency given to the reception unit having a higher priority.
The control unit 116 identifies which of the six states described below the state of the parent device 100 belongs from the usage status of each of the reception units 111 to 114 and the transmission state from the parent device 100 itself to the child device 200. A tone signal corresponding to the state is always generated from the tone signal generator 117.

A memory 124 is connected to the control unit 116, and a table 300 indicating correspondence between the types of tone signals and the transmission frequencies specified by the tone signals, as shown in FIG.
Master device 100 can perform voice communication with slave device 200.

  The transmission unit 122 modulates the audio signal and the tone signal with a single frequency F 1 and transmits the modulated signal from the transmission antenna 123.

  As shown in FIG. 3, each slave unit 200 includes an antenna 201, a receiver 211 that is a slave unit side receiver connected to the antenna 201, a tone detector 212, a controller 213, a memory 214, A transmission unit 215 that is a slave side transmission unit, a transmission frequency setting unit 216, a microphone 217, a squelch circuit 218, a speaker 219, and a PTT switch (PTT) 220 are provided.

  Receiving section 211 receives and demodulates the signal transmitted by base unit 100 at frequency F 1, and provides it to tone detecting section 212.

  The tone detection unit 212 searches for the tone signal from the signal given from the reception unit 211, detects the type of the tone signal, and gives the result to the control unit 213. The memory 214 connected to the control unit 213 indicates whether the tone signal type, the transmission frequency specified by each tone signal, the opening / closing of the squelch, and the PTT operation are invalid as shown in FIG. A table 400 indicating correspondence is described.

The control unit 213 is configured by, for example, a CPU (Central Processing Unit) and the like, and controls the entire child device 200.
The control unit 213 determines a transmission frequency based on the table 400 in the memory 214 and causes the transmission frequency setting unit 216 to generate the determined transmission frequency.
The output side of the microphone 217 is connected to the transmission unit 215 and outputs an audio signal to the transmission unit 215.

  The control unit 213 is connected to the PTT switch 220. The control unit 213 controls validity / invalidity of the PTT switch 220. The control unit 213 determines whether or not the PTT switch 220 has been pressed and notifies the transmission unit 215 of it. The transmission unit 215 modulates the audio signal supplied from the microphone 217 with the transmission frequency generated by the transmission frequency setting unit 216 when the PTT switch 220 is pressed and the PTT switch 220 is valid. And transmitted from the antenna 201.

  The output side of the reception unit 211 is connected to the speaker 219 via the squelch circuit 218. Opening and closing of the squelch circuit 218 is controlled by the control unit 213. The speaker 219 outputs the audio signal given from the receiving unit 211 as audio.

  Hereinafter, a method for controlling transmission of the slave unit 200 while the master unit 100 and the slave unit 200 cooperate with each other will be described.

  First, the processing of base unit 100 will be described with reference to the flowchart shown in FIG. This process is performed periodically.

  The control unit 116 of the base unit 100 checks whether or not the receiving unit currently designated by the base unit 100 among the receiving units 111 to 114 is not in use (step S1). The currently designated receiving unit is a receiving unit designated by the tone signal currently transmitted by the parent device 100.

When the current designated receiving unit is not used (step S1: YES), the control unit 116 ends the process of the parent device.
When the current designated receiving unit is in use (step S1: NO), the control unit 116 determines whether the receiving unit 111 is not in use (step S2).

  When the receiving unit 111 is not in use (step S2: YES), the control unit 116 determines whether all the receiving units 111 to 114 are not in use (step S3). When all the reception units 111 to 114 are not in use (step S3: YES), the control unit 116 determines whether or not the PTT switch 120 is turned off (step S4). Master device 100 transmits the audio signal acquired by microphone 121 as a modulated signal when PTT switch 120 is on, and does not transmit the modulated signal when PTT switch 120 is off.

  When the PTT switch 120 is off (step S4: YES), the control unit 116 determines that all of the events shown in FIG. It is determined that the receiving units 111 to 114 are free (first state), and the tone signal generating unit 117 generates the tone signal fca (step S5).

  When one or more of the reception units 111 to 114 are in use (step S3: NO) and when the PTT switch 120 is turned on in step S4 (step S4: NO) , The control unit 116 is a state in which the PTT switch 120 is turned on or an external audio signal is input and all the reception units 111 to 114 are free, the reception unit 112 and the reception unit among the events illustrated in FIG. 114 is in use, the reception unit 113 and the reception unit 114 are in use, or the reception unit 112 and the reception unit 113 are in use (second state). The tone signal generator 117 generates the tone signal fc1 (step S6).

  When the determination result of step S2 is that the receiving unit 111 is in use (step S2: NO), the control unit 116 determines whether or not the receiving unit 112 is in use (step S7).

  When the reception unit 112 is not in use (step S7: YES), the control unit 116 is in a state where only the reception unit 111 is in use, or the reception unit 111, the reception unit 113, and the reception unit among the events illustrated in FIG. 114 is determined to be in any one of the used states (third state), and the tone signal generator 117 generates the tone signal fc2 (step S8).

  If the determination result in step S7 is that the receiving unit 112 is in use (step S7: NO), the control unit 116 determines whether or not the receiving unit 113 is in use (step S9). When the reception unit 113 is not in use (step S9: YES), the control unit 116 is in a state in which the reception unit 111 and the reception unit 112 are in use or the reception unit 111 and reception among the events illustrated in FIG. It is determined that the unit 112 and the receiving unit 114 are in any one of the used states (fourth state), and the tone signal generating unit 117 generates the tone signal fc3 (step S10).

  If the determination result in step S9 is that the reception unit 113 is in use (step S9: NO), the control unit 116 determines whether or not the reception unit 114 is in use (step S11). When the receiving unit 114 is not in use (step S11: YES), the control unit 116 is in a state in which the receiving unit 111, the receiving unit 112, and the receiving unit 113 are in use (fifth) among the events shown in FIG. The tone signal generator 117 generates the tone signal fc4 (step S12).

  When the determination result of step S11 is that the reception unit 114 is in use (step S11: NO), the control unit 116 receives the reception unit 111, the reception unit 112, the reception unit 113, and the reception among the events illustrated in FIG. It is determined that the unit 114 is in use (sixth state), and the tone signal generation unit 117 generates the tone signal fcb (step S13).

With the above processing, the control unit 116 classifies the state into six states, determines which state is present, and generates a corresponding tone signal.
Specifically, a state in which the PTT switch 120 is off, there is no audio input from the microphone 121, and all the reception units 111 to 114 are not used is determined as the first state, and the tone signal fca is generated. ing.

A state in which only the receiving unit 111 is not used or a state in which a plurality of receiving units including the receiving unit 111 are not used and the receiving unit 111 has the highest priority is determined as the second state. The tone signal fc1 is generated.
A state in which only the receiving unit 112 is not used, or a state in which a plurality of receiving units including the receiving unit 112 are not used and the receiving unit 112 has the highest priority is determined as the third state. The tone signal fc2 is generated.
A state in which only the receiving unit 113 is not used or a state in which a plurality of receiving units including the receiving unit 113 are not used and the receiving unit 113 has the highest priority is determined as the fourth state. The tone signal fc3 is generated.
The state where only the receiving unit 114 is not used is determined as the fifth state, and the tone signal fc4 is generated.
Further, the state where all the receiving units 111 to 114 are used is determined as the sixth state, and the tone signal fcb is generated.

  When an audio signal is input, the transmission unit 122 mixes the audio signal and the tone signal, modulates the signal with a single frequency F1, and transmits it. When no audio signal is input, the tone signal is modulated at a single frequency F1 and transmitted. Therefore, the tone signal is constantly transmitted.

  In this way, base unit 100 can always generate tone signals according to the usage status of the four receiving units.

  Next, the process of the subunit | mobile_unit 200 is demonstrated. When detecting the tone signal fcb, the slave unit 200 invalidates the pressing of the PTT switch 220 and prohibits the transmission of the modulated signal. Hereinafter, the processing of the slave 200 will be described with reference to the flowchart shown in FIG. This process is performed periodically.

  The control unit 213 of the child device 200 determines whether or not the currently set transmission frequency is in a call (step S31), and when not in a call (step S31: NO), the currently set transmission frequency. Is determined to correspond to the received tone signal (step S32).

  When a call is in progress (step S31: YES), and when the transmission frequency corresponds to the tone signal (step S32: YES), the control unit 213 ends the process so that the setting of the transmission frequency does not change. .

  When the determination result in step S32 indicates that the currently set transmission frequency does not correspond to the tone signal (step S32: NO), the control unit 213 detects the tone signal using the tone detection unit 212. (Step S33), it is determined whether or not the detected tone signal is fca (Step S34). When the detected tone signal is not fca (step S34: NO), the control unit 213 determines whether or not the detected tone signal is fc1 (step S35). When the detected tone signal is fc1 (step S35: YES), the control unit 213 opens the squelch circuit 218 (step S36), validates the operation of the PTT switch 220, and transmits it with reference to the table 400 of the memory 214. The transmission frequency F1 corresponding to the tone signal is generated from the frequency setting unit 216, and the transmission frequency of the child device 200 is set to F1 (step S37). When the PTT switch 220 is pressed, the slave unit 200 transmits the set transmission frequency to the master unit 100, and the tone signal transmitted by the master unit 100 is transmitted within a predetermined period (for example, 1 second) after the transmission. Confirming that there is a change, the connection at the transmission frequency F1 is completed. This confirmation process is performed to confirm that communication with the parent device 100 is normal.

  If the detected tone signal is fca (step S34: YES), the control unit 213 closes the squelch circuit 218 (step S38), enables the operation of the PTT switch 220, and sets the transmission frequency. The transmission frequency F1 (see FIG. 7) corresponding to the fca tone signal is specified from the unit 216 and generated, and the transmission frequency of the slave unit 200 is set to F1 (step S37). When the PTT switch 220 is pressed, the slave unit 200 transmits the set transmission frequency to the master unit 100, and the tone signal transmitted by the master unit 100 is transmitted within a predetermined period (for example, 1 second) after the transmission. Confirming that there is a change, the connection at the transmission frequency F1 is completed.

  If the result of determination in step S35 is that the detected tone signal is not fc1 (step S35: NO), the control unit 213 determines whether or not the tone signal is fc2 (step S39). When the tone signal is fc2 (step S39: YES), the control unit 213 opens the squelch circuit 218 (step S40), enables the operation of the PTT switch 220, and responds to the tone signal of fc2 from the transmission frequency setting unit 216. The transmission frequency F2 to be generated is generated, and the transmission frequency of the slave unit 200 is set to F2 (step S41). When the PTT switch 220 is pressed, the slave unit 200 transmits the set transmission frequency to the master unit 100, and the tone signal transmitted by the master unit 100 is transmitted within a predetermined period (for example, 1 second) after the transmission. Confirming that there is a change, the connection at the transmission frequency F2 is completed.

  If the result of determination in step S39 is that the detected tone signal is not fc2 (step S39: NO), the control unit 213 determines whether or not the tone signal is fc3 (step S42). When the tone signal is fc3 (step S42: YES), the control unit 213 opens the squelch circuit 218 (step S43), enables the operation of the PTT switch 220, and responds to the tone signal of the fc3 from the transmission frequency setting unit 216. The transmission frequency F3 to be generated is generated, and the transmission frequency of the slave unit 200 is set to F3 (step S44). When the PTT switch 220 is pressed, the slave unit 200 transmits the set transmission frequency to the master unit 100, and the tone signal transmitted by the master unit 100 is transmitted within a predetermined period (for example, 1 second) after the transmission. Confirming that there is a change, the connection at the transmission frequency F3 is completed.

  If the result of determination in step S42 is that the detected tone signal is not fc3 (step S42: NO), the control unit 213 determines whether or not the tone signal is fc4 (step S45). When the tone signal is fc4 (step S45: YES), the control unit 213 opens the squelch circuit 218 (step S46), enables the operation of the PTT switch 220, and responds to the tone signal of the fc4 from the transmission frequency setting unit 216. The transmission frequency F4 to be generated is generated, and the transmission frequency of the slave unit 200 is set to F4 (step S47). When the PTT switch 220 is pressed, the slave unit 200 transmits the set transmission frequency to the master unit 100, and the tone signal transmitted by the master unit 100 is transmitted within a predetermined period (for example, 1 second) after the transmission. Confirming that there is a change, the connection at the transmission frequency F4 is completed.

  If the determination result in step S45 is that the detected tone signal is not fc4 (step S45: NO), the control unit 213 determines whether or not the tone signal is fcb (step S48). When the tone signal is fcb (step S48: YES), the control unit 213 opens the squelch circuit 218 (step S49), invalidates the operation of the PTT switch 220, and invalidates the transmission frequency from the transmission frequency setting unit 216. (Step S50).

  If the detected tone signal is not fcb (step S48: NO), the control unit 213 closes the squelch circuit 218 (step S51) and ends the process.

  In this way, the slave unit 200 can determine the usage status of the four master unit side receiving units based on the tone signal received from the master unit 100, and can limit communication according to the determination result.

  As described above, in this embodiment, the empty states of the transmission frequencies F1 to F4 are detected from the usage status of the reception units 111 to 114, and the tone signals fc1 to fc4, fca, and fcb as corresponding information are detected by the slave unit 200. Sent to the side. The subunit | mobile_unit 200 can set the kind of transmission frequency F1-F4 according to the kind of tone signal fc1-fc4, fca, fcb. Therefore, even if the encoding circuit and the decoder are not provided in the parent device 100 or the child device 200, simultaneous calls can be performed without any trouble. Further, the number of receiving units 111 to 114 of the parent device 100 and the number of child devices 200 do not have to match, and the number of child devices 200 under the parent device 100 can be increased. In addition, the slave unit 200 can limit communication according to the types of tone signals fc1 to fc4, fca, and fcb.

In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible.
For example, the number of receiving units 111 to 114 is not limited to four, and may be further increased.

  In the above embodiment, when all the reception units of base unit 100 are in use, slave unit 200 does not transmit a modulated signal. However, the number of reception units in base unit 100 is in use. When the number reaches a predetermined number, handset 200 may not transmit the modulated signal.

  Further, specific details of the structure and the like can be changed as appropriate.

It is a block diagram of the radio | wireless communications system which concerns on embodiment of this invention. It is a block diagram which shows the main | base station in FIG. It is a block diagram which shows the subunit | mobile_unit in FIG. It is a table which shows the tone signal corresponding to the use condition of the receiving part which a main | base station stores in memory. It is a table | surface which shows the relationship between the tone signal which a subunit | mobile_unit stores in a memory, the transmission frequency to set, opening / closing of a squelch, and invalidity | validity / validity of a PTT switch. It is a flowchart which shows the process of a main | base station. It is a flowchart which shows the process of a subunit | mobile_unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Base unit 111-114 Reception part 115 Audio | voice mixing part 116 Control part 117 Tone signal generation part 120 PTT switch 121 Microphone 122 Transmission part 200 Slave apparatus 211 Reception part 212 Tone detection part 213 Control part 214 Memory 215 Transmission part 216 Transmission frequency setting Part 217 Microphone 220 PTT switch 300 Table 400 Table

Claims (5)

Each of the modulated signals modulated at different n-channel frequencies is received and demodulated, and the n parent device side receiving units that respectively generate the demodulated signals, and the demodulation generated by the n parent device side receiving units. A master unit including a mixing unit that mixes signals, a master unit side transmission unit that modulates and transmits a demodulated signal mixed by the mixing unit at a single frequency, and
Receives and demodulates the modulated signal transmitted from the master unit, generates a demodulated signal, a slave unit side receiver, an output unit that outputs the demodulated signal generated by the slave unit side receiver, and the frequency of the n channel A wireless communication system comprising: a frequency control unit that sets a transmission frequency from the mobile station; and an arbitrary number of slave units including a slave unit side transmission unit that transmits a modulated signal modulated at a frequency set by the frequency control unit to the master unit Because
The base unit is
Information detecting means for detecting information indicating a vacant frequency among the frequencies of the n channels from the usage status of the base-side receiving unit;
Tone signal generating means for constantly generating a tone signal corresponding to information relating to an empty frequency among the frequencies of the n channels detected by the information detecting means,
The slave is
Table storage means for storing a table associating the tone signal with whether or not the modulated signal can be transmitted;
Tone signal receiving means for receiving the tone signal generated by the tone signal generating means;
Control means for controlling whether or not to transmit the modulated signal to the handset side transmission unit based on the tone signal received by the tone signal receiving means and the table stored in the table storage means. ,
A wireless communication system. The control means includes
When the tone signal received by the tone signal receiving means indicates that all the frequencies of the n-channel frequencies are in use, control is performed so as not to transmit the modulated signal by the slave side transmitter. ,
The wireless communication system according to claim 1. The control means includes
Control is performed so that the slave unit transmitting unit does not transmit the modulated signal when the tone signal received by the tone signal receiving means indicates that a predetermined number of frequencies of the n channel frequencies are in use. To
The wireless communication system according to claim 1. Each of the modulated signals modulated at different n-channel frequencies is received and demodulated, and the n parent device side receiving units that respectively generate the demodulated signals, and the demodulation generated by the n parent device side receiving units. Receiving a modulated signal transmitted from a master unit having a mixing unit for mixing signals, and a master-side transmitting unit for transmitting a modulated signal by modulating a demodulated signal mixed by the mixing unit at a single frequency A modulated signal receiving unit that generates a demodulated signal, an output unit that outputs a demodulated signal generated by the modulated signal receiving unit, a frequency control unit that sets a transmission frequency from the n-channel frequency, and the frequency A wireless terminal including a modulated signal transmitting unit that transmits a modulated signal modulated at a frequency set by a control unit to the master unit,
Tone signal receiving means for receiving a tone signal corresponding to information indicating an idle frequency among the frequencies of the n channels from the base unit;
Table storage means for storing a table associating the tone signal with whether or not the modulated signal can be transmitted;
Control means for controlling whether or not to send the modulated signal to the modulated signal transmission section based on the tone signal received by the tone signal receiving means and the table stored in the table storage means. ,
A wireless terminal characterized by that. Receiving and demodulating modulated signals modulated with different n-channel frequencies, respectively, n master unit receiving units for generating demodulated signals, and demodulated signals generated by the n master unit receiving units Receiving a modulated signal transmitted from a base unit having a base unit side transmission unit that modulates a demodulated signal mixed by the mixing unit with a single frequency and transmits the modulated signal. A modulated signal receiving unit that demodulates and generates a demodulated signal, an output unit that outputs a demodulated signal generated by the modulated signal receiving unit, a frequency control unit that sets a transmission frequency from the frequency of the n channel, and the frequency control A computer including a modulated signal transmitting unit that transmits a modulated signal modulated at a frequency set by the unit to the master unit;
A table storage means for storing a table in which a tone signal corresponding to information indicating an empty frequency among the frequencies of the n channels of the base-side receiving unit is associated with whether or not a modulated signal can be transmitted;
Based on the tone signal received from the base unit by the modulated signal receiving unit and the table stored in the table storage unit, the modulated signal transmitting unit controls whether or not to transmit the modulated signal. Control means,
A program characterized by functioning as

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