JP2859230B2 - Communication monitoring and control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle communication monitoring and control device used in a single type mobile radio system in which a plurality of mobile radio stations share the same frequency.

[0002]

2. Description of the Related Art Conventionally, in a mobile radio system in which a plurality of mobile radio stations share the same frequency, a dedicated radio device (Japanese Patent Application Laid-Open No. 62-1) is used to prevent interference due to simultaneous transmission.
No. 07543).

[0003] The above wireless device monitors the communication state,
A communication monitoring control device that controls the transmission operation based on the monitoring result is built in. That is, when transmitting the data or the voice signal, the communication monitoring and control device monitors a carrier transmitted from another wireless device for a certain period of time, and performs a transmitting operation if the carrier is not detected. On the other hand, when the carrier is detected, the communication monitoring control device performs a transmission operation after the carrier is no longer detected.

[0004]

By the way, in the conventional mobile radio system, when a new system is constructed, a dedicated radio device having a new communication monitoring and control device is required. Therefore, in the conventional mobile radio system, there is a drawback that an existing radio device without a built-in communication monitoring and control device cannot be effectively used. The present invention has been made under such a background,
It is an object of the present invention to provide a communication monitoring and control device that can reduce the cost when introducing a new system and that can easily prevent interference with another wireless device using an existing device.

[0005]

According to a first aspect of the present invention, there is provided a communication monitoring and control device which is mounted on a vehicle and is removably inserted between an existing wireless device and an existing handset. Determining means for determining whether or not another wireless device is performing communication based on a demodulated signal output from the wireless device; and the other wireless device performing communication based on a determination result of the determining means. A location registration control unit that outputs location registration information relating to the location registration of the vehicle to the transmission unit of the wireless device when the location registration is not performed.

According to a second aspect of the present invention, in the communication monitoring and control apparatus according to the first aspect, the determining means determines that the level of the demodulated signal is equal to or less than a predetermined threshold value. The wireless device determines that the wireless device is not performing communication, while determining that the other wireless device is performing communication when the level of the demodulated signal is higher than the threshold value. And

According to a third aspect of the present invention, in the communication monitoring and controlling apparatus according to the second aspect, the transmitter / receiver is used only when the determining means determines that the other wireless device is not performing communication. The wireless communication device further comprises an audio communication control unit that outputs an audio signal output from the wireless device to a transmission unit of the wireless device and permits audio transmission in the wireless device.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a wireless device to which a communication monitoring control device according to an embodiment of the present invention is applied. The wireless device shown in this figure is mounted on a vehicle, for example, an AVM (Automatic Vehicle).
Monitoring: Automatic display of vehicle position) Used as a mobile terminal in a system. Here, the AVM system is a mobile radio system in which a plurality of mobile radio stations share the same frequency, and refers to a system that monitors the current position of a plurality of vehicles (for example, taxi).

In FIG. 1, reference numeral 1 denotes an existing wireless device having a receiving unit and a transmitting unit (not shown), which receives or transmits radio waves via an antenna 2 and wirelessly communicates with another wireless device (not shown). Perform communication. The receiving unit of the wireless device 1 includes:
The received signal received via the antenna 2 is demodulated and output as a demodulated signal Sd. The demodulated signal Sd includes an audio signal or an AVM signal. The voice signal is a voice signal of a communication partner in normal wireless communication. The AVM signal is a signal indicating position information transmitted from a base station (not shown) in the AVM system. This position information is a signal indicating the position where the vehicle on which the wireless device is mounted is present.

The transmitting unit of the wireless device 1 transmits the input audio signal Sa or MSK (Minimum Shift Keying) signal SMSK via the antenna 2. The audio signal S
a is a voice signal in normal wireless communication. The MSK signal SMSK is a signal representing position registration information obtained by adding vehicle number information unique to the vehicle to position information obtained from the above-described AVM signal.

Reference numeral 3 denotes a connector provided on the wireless device 1, to which one end of a cable 4 composed of four transmission lines is connected. Reference numeral 5 denotes a communication monitoring and control device which is detachably inserted between the wireless device 1 and the handset 6 via the cable 4 via a connector (not shown). Device. That is, the communication monitoring control device 5
Is a device used when the existing wireless device 1 and handset 6 are used in the AVM system.

The handset 6 has a receiver, a transmitter, and a transmission switch 6a (not shown). The receiver converts an input demodulated signal Sd into voice,
On the other hand, the transmitter converts the speaker's voice into a voice signal Sa. The transmission switch 6a is a switch that is pressed by a speaker during transmission, and the handset 6 outputs a transmission request signal Ss when the transmission switch 6a is pressed, while the transmission switch 6a is not pressed. At this time, the output of the transmission request signal Ss is stopped.

The communication monitoring and control device 5 has a function of monitoring the state of the demodulated signal Sd to be input, and controlling the transmission of the radio 1 based on the monitoring result, and a position registration function in the AVM system. Have. In the communication monitoring and control device 5, reference numeral 7 denotes a demodulation signal detection unit which compares the level of the input demodulation signal Sd with a preset threshold value so that the level of the demodulation signal Sd is higher than the threshold value. When the value is large, a transmission prohibition signal Sk indicating that the demodulation signal Sd has been detected is output. The transmission prohibition signal Sk is a signal for instructing prohibition of the transmission operation performed by the wireless device 1.

Reference numeral 8 denotes a switch interposed between the handset 6 and the wireless device 1, which is turned off while the transmission prohibition signal Sk is being input, while the transmission prohibition signal Sk is not being input. It is turned on for a while.

Reference numeral 9 denotes a control unit for performing various controls related to the AVM system. The control unit 9 analyzes the input demodulated signal Sd (AVM signal) to obtain position information, and then adds the vehicle number information unique to the vehicle to the position information. Is subjected to MSK modulation, and this is output as an MSK signal SMSK. 10
Is a two-input one-output type changeover switch, one input terminal of which is connected to the handset 6, the other input terminal of which is connected to the control unit 9, and the output terminal of which is connected to the wireless device 1 via the cable 4. Have been.

Next, the operation of the wireless device to which the communication monitoring and control device according to the above-described embodiment is applied will be described. First, the location registration operation in the AVM system will be described. When the changeover switch 10 shown in FIG. 1 is switched to the control unit 9 side and the vehicle is located in a transmission area of a base station (not shown), the base station transmits radio waves including position information of the transmission area. Is transmitted, the radio wave is transmitted to the wireless device 1 via the antenna 2.
Is received by the receiving unit.

As a result, the demodulated signal Sd (position information) is output from the receiving unit of the wireless device 1 to the demodulated signal detecting unit 7, the control unit 9, and the handset 6 via the cable 4. The demodulated signal detector 7 compares the level of the input demodulated signal Sd (position information) with a threshold.
Now, assuming that the level of the demodulated signal Sd is larger than the threshold, the demodulated signal detector 7 outputs a transmission prohibition signal Sk to the switch 8. As a result, even if the switch 8 is turned off and the transmission switch 6a of the handset 6 is pressed to output the transmission request signal Ss, the transmission request signal Ss is not input to the wireless device 1. That is, the wireless device 1 is in a transmission prohibited state.

When the demodulated signal Sd (position signal) is input to the control unit 9, the control unit 9 obtains position information by analyzing the demodulated signal Sd (position signal), and then obtains the position information. The location registration information to which the vehicle number of the vehicle is added is generated. Next, the control unit 9 outputs the result of performing MSK modulation on the position registration information as an MSK signal SMSK. Thus, the MSK signal SMSK is input to the transmission unit of the wireless device 1 via the changeover switch 10 and the cable 4 and then transmitted via the antenna 2;
Further, it is received by the base station. Thereby, the position of the vehicle is registered.

Also, during the above-described location registration operation,
Assuming that the transmission switch 6a of the handset 6 is pressed, the handset 6 outputs a transmission request signal Ss. However, since the switch 8 is turned off, the transmission request signal Ss is not input to the wireless device 1. Therefore, the radio 1 performs the receiving operation and the MSK signal S
In this state, only the MSK transmission operation is performed, and the audio signal Sa is not transmitted.

Next, the voice communication operation of the wireless device to which the communication monitoring and control device according to the embodiment is applied will be described. Now, in a state where the changeover switch 10 is switched to the handset 6 side and the radio 1 does not receive any signal, a zero demodulation signal Sd is demodulated from the radio 1 via the cable 4. The signals are output to the signal detection unit 7, the control unit 9, and the handset 6, respectively. In this case, since the level of the demodulated signal Sd is equal to or lower than the threshold,
The demodulation signal detector 7 does not output the transmission prohibition signal Sk. Therefore, the switch 8 is turned on, and the radio 1
Is in a state where the audio signal Sa can be transmitted. Also,
The control unit 9 does not perform any processing because the input demodulated signal Sd is not a position signal. Also, handset 6
When the demodulation signal Sd is input to the handset 6, no sound is output from the handset 6 because the level is zero.

When the speaker presses the transmission switch 6a of the handset 6 to transmit voice, the handset 6 outputs a transmission request signal Ss to the wireless device 1 via the switch 8 and the cable 4. You. Thereby, the wireless device 1 recognizes that the transmission of the audio signal Sa has been requested.

Next, when the speaker utters a voice to the transmitter of the handset 6, the voice is converted into a voice signal Sa by the transmitter. Then, the audio signal Sa is output to the transmission unit of the wireless device 1 via the changeover switch 10 and the cable 4. Thereby, the audio signal Sa
Is transmitted from the transmission unit via the antenna 2.

An audio signal transmitted from a wireless device (not shown) on the other side is transmitted to the wireless device 1 via the antenna 2.
As a result, the demodulated signal Sd (audio signal) is output from the receiving unit of the wireless device 1 to the demodulated signal detecting unit 7 via the cable 4. Now, assuming that the level of the demodulated signal Sd is higher than the threshold, the demodulated signal detector 7
, The transmission prohibition signal Sk is output to the switch 8.
As a result, the switch 8 is turned off, and the wireless device 1 is set to the transmission prohibited state.

Assuming that the transmission switch 6a of the handset 6 is pressed, the handset 6 outputs a transmission request signal Ss. However, since the switch 8 is turned off, the transmission request signal Ss is not input to the wireless device 1. Therefore, even if the audio signal Sa is input from the handset 6 to the wireless device 1 via the cable 4, The device 1 does not transmit the audio signal Sa.

As described above, according to the communication monitoring and control device 5 according to the above-described embodiment, the existing radio 1 and the handset 6 can be used for the AVM system. Therefore, according to the communication monitoring and controlling apparatus 5 according to the embodiment, it is possible to support the AVM system by effectively using the existing wireless device 1 and the handset 6 without using a dedicated wireless device compatible with the AVM system. Therefore, the effect that the cost at the time of introducing the system can be reduced is obtained. Further, according to the communication monitoring and control device 5 according to the above-described embodiment, the versatility of the existing wireless device 1 and the handset 6 can be improved.

Further, according to the communication monitoring and control device 5 according to the above-described embodiment, the communication state of the wireless device 1 is monitored,
While the audio signal or the AVM signal is being transmitted from the wireless device of the other party, control is performed so as not to transmit the signal itself.
Interference can be prevented.

[0027]

According to the first or second aspect of the present invention, the location registration system can be used by using the existing wireless device and the existing handset, so that the cost when introducing the system can be reduced. can do. According to the first or second aspect of the invention, the versatility of the existing wireless device and the existing handset can be improved. Further, according to the third aspect of the present invention, it is possible to easily prevent interference with another wireless device by using the existing wireless device and the existing handset.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a wireless device to which a communication monitoring control device according to an embodiment of the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radio 5 Communication monitoring and control apparatus 6 Handset 7 Demodulation signal detection part 8 Switch 9 Control part 10 Changeover switch

Claims (3)

(57) [Claims] 1. A communication monitoring and control device detachably inserted between an existing wireless device mounted on a vehicle and an existing handset, based on a demodulated signal output from the wireless device. Determining means for determining whether or not another wireless device is performing communication; and, based on the determination result of the determining means, when the other wireless device is not performing communication, location registration related to location registration of the vehicle. And a position registration control unit for outputting information to a transmission unit of the wireless device. 2. The method according to claim 1, wherein when the level of the demodulated signal is equal to or less than a predetermined threshold value, the determining unit determines that the other wireless device is not performing communication. 2. The communication monitoring control apparatus according to claim 1, wherein when the level is larger than the threshold value, it is determined that the other wireless device is communicating. 3. An audio signal output from the handset is output to a transmitter of the wireless device only when the determining means determines that the other wireless device is not performing communication. The communication monitoring control device according to claim 2, further comprising: a voice communication control unit that permits voice transmission in the wireless device.