JPH0923286A - Communication interface device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inform a data communication equipment for a wired line connecting to a mobile radio equipment that a level of a signal from a base station reaches a prescribed level or below. SOLUTION: A busy tone generator 12 has a 400Hz oscillator 12a. A state discrimination section 10 discriminates the communication enable state of a mobile radio equipment 7 based on the level of a signal on a control signal line CL and provides the output of the discrimination result to a control signal 11. The control section 11 applies on/off control to a relay 13 of a service tone generator 12 when the communication is disable based on the discrimination result to allow the generator 12 to generate a busy tone. The busy tone is fed to wired public line terminals L1, L2 of a facsimile equipment depending on a thrown position of a switch 2b. thus, the facsimile equipment 1 recognizes disable communication to avoid a useless call and the communication is interrupted by a regular procedure during the communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication interface device, and more particularly to an interface device between a car telephone and a data communication device connected to the car telephone by wire.

[0002]

2. Description of the Related Art A mobile station, that is, a mobile radio apparatus such as a car telephone detects the level of a control signal from a base station when the power is turned on. If the level of the control signal is equal to or higher than the specified value, the procedure shifts to the standby state and the procedure proceeds. However, if the mobile station is inside a tunnel, behind a building, or moving to a place other than the service area, the reception level may drop and may not reach the specified value. In this case, communication cannot be performed without shifting to the standby state. In a car telephone, a warning or a display is given when the control level is lowered and communication is impossible, so that the call is abandoned and waits until the level of the control signal exceeds a specified value.

Furthermore, in the case of a failure or construction of the base station,
The regulation information may be sent from the base station by a PDS / MBS signal. The car telephone is configured to analyze the PDS / MBS signal and stop the transition to the standby state or regulate the state.

In addition, a data communication device for a wired telephone line such as a facsimile device may be connected to a car telephone as a rear connection device. An example in which a facsimile device is connected to an automobile telephone is disclosed in Japanese Patent Laid-Open No. 64-73968. FIG. 7 is a block diagram showing an example of an interface device between a radio device of a car telephone and a facsimile device. In the figure, the wireless device and the handset (not shown) are directly connected by a control signal line CL, an off-hook control line OH, an incoming signal line OP5, and a ground line GND. The transmission line TX and the reception line RX of the wireless device are connected to a facsimile device (not shown) and a handset via transformers T1 and T2 and a switching unit 2.

The facsimile (FAX) operation detection off-hook control section 3 detects the operation of the facsimile apparatus by the potential on the switching section 2 side of the transformers T1 and T2, and connects the off-hook control line OH and the ground line GND to the wireless apparatus. Turn off the off-hook signal of. Line voltage generator 4
Is to apply a DC voltage between the switch 2 side of the transformer T2 and the off-hook control line OH / ground line GND during transmission. The incoming call detection unit 5 detects an incoming call and the detection signal is input to the ringing generation unit 6. The ringing generator 6 issues a ringing signal in response to the incoming call detection signal to notify the incoming call. The switching control unit 2a controls the switch 2b to the facsimile machine side in response to a ringing signal or a call request from the facsimile machine.

Normally, the switch 2b is switched to the handset side, and executes a scheduled call operation or call receiving operation in response to an incoming call detection signal or a call request, and is switched to the facsimile machine side. The FAX operation detection off-hook control unit 3 detects the switching of the switch 2b, connects the off-hook control line OH and the ground line GND, and turns on the off-hook signal. Upon detection of this, the wireless device turns off the incoming signal, resulting in the ringing signal stopping. With the above operation, the connection is completed, and the facsimile device 1 can communicate.

In the car telephone system having such a posterior connection device, there is no means for notifying the posterior connection device from the car telephone when the control signal level is equal to or lower than a specified value. It was For this,
There is a problem in that the succeeding connection device wastefully makes a call request even when the control signal level is low, or cannot proceed to the communication interruption procedure even when the wireless line is disconnected during communication.

On the other hand, in Japanese Patent Laid-Open No. 63-299414, the operation of facsimile transmission is prohibited when the reception level of the reference wave (corresponding to the control signal) output from the relay station is below a specified value. A wireless facsimile machine has been proposed.

[0009]

The above-mentioned conventional techniques have the following problems. That is, JP-A-63-299
The device described in Japanese Patent No. 414 is a wireless facsimile device in which a facsimile device and a wireless device are integrated. Therefore, when a facsimile device is retrofitted to a car phone, a special control line is required in addition to the standard connection line that has been conventionally required for connecting the car phone and the facsimile device. For this reason, it was difficult to transfer the technology of the wireless facsimile machine described in the above publication to a general-purpose facsimile machine.

An object of the present invention is to solve the above problems,
It is an object of the present invention to provide a communication interface device capable of notifying a succeeding connection device such as a general-purpose facsimile device connected to a car phone of whether or not connection with a wireless line is possible.

[0011]

DISCLOSURE OF THE INVENTION In order to solve the above problems and achieve the object, the present invention provides a communication for connecting a transmission line and a reception line of a mobile radio device to a wired public line terminal of a data communication device. In the interface device for service, a service tone generating means connected to a wired public line terminal of the data communication device, a state determining means for determining whether or not the mobile wireless device is in a standby state, and a standby state for the mobile wireless device. The first feature is that the apparatus further comprises control means for instructing the service tone generation means to output a service tone indicating that communication is impossible when it is determined that the service tone generation means is not in a state.

Further, the present invention further comprises hook detecting means of the data communication device, wherein the control means is judged to be in a standby state, and the hook detecting means detects an off-hook of the data communication device. A second feature is that the instruction is made to output a service tone indicating that communication is impossible.

Further, according to the present invention, the level detecting means for judging whether or not the carrier of the wireless channel being communicated is at a level equal to or higher than a specified value at which communication is possible, and the control means, A third feature is that the service tone generating means is instructed to output a service tone indicating that communication is impossible when it is determined that the value is not greater than or equal to a specified value.

According to the above-mentioned first feature, when the wireless communication is not possible, it is possible to notify the data communication device connected to the mobile wireless device that the communication is impossible by using the service tone. . The data communication device can recognize the service tone through the wired public line terminal. Further, according to the second feature, the service tone is transmitted to the data communication device only on the assumption that the data communication device is off-hook, that is, when the data communication device is actually trying to communicate or is communicating. Further, according to the third feature, when the wireless carrier is lowered during communication and communication cannot be continued, the data communication device is notified of communication failure.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. First, the configuration of a mobile telephone system including the interface device of the present invention will be described with reference to FIG.
In the figure, a handset 9 and a facsimile device 1 are connected to a wireless device 7 via an interface device 8. The interface device 8 has at least a means for determining which of the handset 9 and the facsimile device 1 is to be connected to the wireless device 7 and a switching means based on this determination, and also has a function peculiar to the present invention described later. I have it.

Next, the interface device 8 will be described in detail. FIG. 1 is a block diagram showing the configuration of the interface device, and the same reference numerals as those in FIG. 7 indicate the same or equivalent parts. In the figure, the reception line RX of the wireless device 7
And the transmission line TX is the transformer T2 and the switch 2
Wired public line terminal L of the facsimile device 1 via b
1 and L2. The control signal line CL between the wireless device 7 and the handset 9 is at a level equal to or higher than the specified value when the wireless device 7 is in the standby state, and is at a level equal to or lower than the specified value when the wireless device 7 is not in the standby state. This level is, for example, 10 dBμV. That is, in the communicable state, the level of the control signal line CL is 10 dBμV or higher.

The state discriminating section 10 is composed of a comparator, compares the signal level of the control signal line CL with the specified value, and if the signal level of the control signal line CL is not less than the specified value, outputs a high level "H" signal. If it is below the specified value, a low level "L" signal is output. The control unit 11 is composed of a microcomputer (CPU), analyzes the output signal of the state determination unit 10 and generates a busy tone BT when it is determined that it is not in the standby state, and dials when it is determined that it is in the standby state. A signal is output which controls the service tone generator 12 to generate the tone DT.

Service tone generator 12 is configured to generate various service tones. Specifically, the busy tone BT has a frequency of 400 Hz and a cadence of 500 m.
s on / 500ms off, output level is -10dBm repetitive signal, dial tone DT frequency 400
It is a continuous signal of Hz.

The service tone generator 12 is 400H
It is composed of an oscillator 12a for outputting a signal of z and a relay 13, and the relay 13 is turned on / off by a signal from the control section 11. For example, the relay 13 is continuously turned on to generate a dial tone DT having a frequency of 400 Hz. If the relay 13 is turned on / off intermittently, a busy tone BT is generated. That is, the control unit 11
A timer means for counting 0 ms to increase the time is provided.
When the busy tone BT occurs, an intermittent signal of 500 ms on / 500 ms off is generated at the timing of the time-up of the timer means to open / close the relay 13.

The service tone generator 12 is a relay 1
3 is connected to the switching unit 2 side of the transformer T2, and when the relay 13 is turned on by a signal from the control unit 11, a service tone is applied to the switching unit 2 side of the transformer T2. Rockwell R9 as the oscillator 12a
A dedicated IC chip such as 6DFX or a Wien bridge type oscillation circuit can be used.

The state discriminating section 10 uses the control signal line C
It is not limited to monitoring L. For example, the wireless device 7 is provided with a register or a memory, and the register or the memory is set to stand by so as to write the phases of outgoing call, incoming call, and call. Then, the state determination unit 10 may be configured to determine from this register or memory whether or not it is in the standby state and output a determination signal to the control unit 11.

The wireless device 7 has a function of constantly monitoring and displaying the reception level of the wireless channel during communication or communication. Therefore, the state determination unit 10 is provided with a function of detecting that the reception level has dropped below a specified value,
When the reception level becomes lower than the specified value, the control unit 11
Output a detection signal.

With the above configuration, when the power of the car telephone is turned on, the wireless device 7 communicates with the base station, and when the control signal level is above the specified value, the wireless device 7 shifts to the standby state and the control signal level is below the specified value. If it is, it does not shift to the standby state. When there is a call request from the facsimile device 1, the switching control unit 2a switches the switch 2b to the facsimile device 1 side. By switching the switch 2b, the facsimile apparatus 1 reads the states of the transmission line TX and the reception line RX. When the wireless device 7 is in the standby state,
The controller 11 continuously turns on the relay 13 to generate the dial tone DT, and when not in the standby state, intermittently turns on the relay 13 to generate the busy tone BT. The facsimile device 1 detects the dial tone DT and the busy tone BT and performs a predetermined operation.

Next, the operation of the control unit 11 will be described with reference to the flowchart. First, as the first embodiment, in step S1 of FIG. 3, the output signal of the state determination unit 10 is read. Here, it is assumed that either the standby state is determined based on the signal level taken in from the control signal line CL, or the standby state is determined from the state of the register or the memory of the wireless device 7. it can. Therefore, although the state determination unit 10 is configured in advance corresponding to either one of the cases, any of the cases can be processed according to this flowchart.

In step S2, it is determined based on the level of the output signal whether or not it is in the standby state. That is, if the output signal is “H”, the wireless device 7 is in the standby state, and if the output signal is “L”, the wireless device 7 is in the standby state.
Is not in standby mode, that is, communication is not possible. If it is not in the standby state, the process proceeds to step S3, and the process of generating the busy tone BT is executed. This process will be described later with reference to FIG.

After the busy tone BT is generated, the process returns to step S1. In the standby state, the determination in step S2 becomes affirmative, and the process proceeds to step S4 to generate a dial tone DT. That is, the relay 13 is turned on and 40
A 0 Hz signal is sent to the facsimile machine 1. In step S5, it is determined whether or not there is a call from the facsimile machine 1 or an incoming call from the outside. If there is a call or a call, the relay 13 is turned off and the process proceeds to step S6 to start control for communication following the call or the call. Step S5
If the determination is negative, the process returns to step S1.

Next, the details of the busy tone generation process will be described with reference to the flowchart of FIG. In the figure, a timer is initialized in step S30. The initial value of this timer is 500 ms corresponding to the on time of the cadence of the busy tone BT. In step S31, the timer is started. In step S32, relay 1
Turn on 3. If the switch 2b is switched to the facsimile machine 1 side by turning on the relay 13, a signal having a frequency of 400 Hz is supplied to the facsimile machine 1.

In step S33, it is determined whether the timer has expired. If the initial value of 500 ms elapses and the time is up, the process proceeds to step S34, and the timer is initialized to set the relay off time. The initial value of this timer is 50, which corresponds to the off time of the cadence of the busy tone BT.
0 ms. In step S35, the timer is started. In step S36, the relay 13 is turned off to stop the output of the signal having the frequency of 400 Hz. Step S3
At 7, it is determined whether the timer has expired. 500 m
When the initial value of s has passed and the time is up, the processing for generating the busy tone BT is finished.

Next, a second embodiment will be described with reference to the flowchart of FIG. In this example, the busy tone BT is generated when the facsimile apparatus 1 is in the off-hook state when not in the standby state. In FIG. 5, in step S10, the output signal of the state determination unit 10 is read. In step S11, it is determined based on the level of the output signal whether or not it is in the standby state. If it is determined that it is not in the standby state, the process proceeds to step S12, and it is determined whether or not the facsimile device 1 is off-hook. Whether it is off-hook or not can be determined by the detection result of the FAX operation detection off-hook controller 3. If it is determined to be off-hook, the process proceeds to step S13,
Generate a busy tone BT. The process of generating the busy tone BT has been described with reference to FIG.

In the case of the standby state, the determination in step S11 becomes affirmative, and the process proceeds to step S14 and step S14.
Similar to 12, it is determined whether the facsimile machine 1 is off-hook. If it is determined to be off-hook, step S
Proceed to 15 to connect to the line. If it is determined that it is not off-hook, the determinations in steps S12 and S14 are both negative, and the process proceeds to step S10.

Next, a third embodiment will be described with reference to the flowchart of FIG. In this example, the busy tone BT is generated when the reception level, that is, the carrier of the radio channel, becomes equal to or lower than a specified value during communication with the facsimile device 1. In FIG. 6, in step S20, it is determined whether or not the facsimile device 1 is in communication. If it is determined that communication is in progress, the process proceeds to step S21, and the reception level from the state determination unit 10 is a specified value (for example, 10 dBμV).
The data indicating whether or not the following is read. Here, the data read from the state determination unit 10 is the control channel (PC
This is different from the case of the above-described first embodiment in that it is not the signal level determination result of H) but the wireless channel signal level determination result.

In step S22, it is determined from the data read from the state determination section 10 whether the reception level is less than the specified value. If it is determined that the reception level is less than or equal to the specified value, the process proceeds to step S23, and it is determined whether or not the hook is off-hook. Since it is determined in step S20 that communication is in progress, the first determination should be affirmative.
If off-hook is detected, the process proceeds to step S24,
A busy tone BT is generated to notify the facsimile apparatus 1 that the reception level is low. Busy tone B
The process of generating T has been described with reference to FIG.

When it is determined that communication is not in progress, when it is determined that the reception level is equal to or higher than the specified value, and when the off-hook is not detected because the facsimile device 1 has stopped communication in response to the busy tone BT, the steps are respectively performed. The determinations in S20, S23, and S24 are negative, and in these cases, it is not necessary to generate the busy tone BT, so the processing of this flowchart ends.

As described above, in the present embodiment, communication availability is notified by the service tone that the facsimile device 1 can recognize based on the level of the control signal and the signal reception level during communication. In the present embodiment, the facsimile device is described as an example of the posterior connection device to be connected to the car telephone, but even when a personal computer or the like having a digital communication function is provided as the posterior connection device, the above-described implementation is performed. Of course, the present invention can be implemented by modifying the examples. Also, instead of the car telephone, for example, PH
The present invention can also be applied to mobile wireless devices such as S, amateur wireless devices, MCA, and ship / airplane telephones.

[0035]

As is apparent from the above description, according to the inventions of claims 1 to 3, when the mobile radio device is in a state in which communication is not possible, the posterior connection connected to the mobile radio device is established. The data communication device as a device can be notified that communication is not possible. Therefore, it is possible to prevent the succeeding connection device from making unnecessary call operation when the communication is impossible.

Since the data communication device can recognize the notification through the reception line and the transmission line, it is not necessary to provide a special signal line other than the reception line and the transmission line between the mobile radio device and the data communication device. Therefore, the data communication device connected to the mobile wireless device has no special limitation for connection. Further, claim 3
According to the invention, since the communication is not suddenly interrupted in a silent state, the data communication apparatus can execute the regular procedure at the time of communication interruption.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an interface device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a mobile telephone system according to an embodiment of the present invention.

FIG. 3 is a flowchart showing an operation in the first embodiment.

FIG. 4 is a flowchart showing a process of generating a busy tone.

FIG. 5 is a flowchart showing an operation in the second embodiment.

FIG. 6 is a flowchart showing an operation according to the third embodiment.

FIG. 7 is a block diagram showing a configuration of a conventional interface device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Facsimile device, 2 ... Switching part, 3 ... FAX operation detection off-hook control part, 7 ... Wireless device, 10 ... State determination part, 11 ... Control part, 12 ... Service tone generator, 13 ... Relay

Claims (3)

[Claims] 1. A communication interface device for connecting a transmission line and a reception line of a mobile radio device to a wired public line terminal of a data communication device, wherein a service tone is connected to the wired public line terminal of the data communication device. Means, a state determination means for determining whether or not the mobile wireless device is in a standby state, and a communication disabled state for the service tone generation means when it is determined that the mobile wireless device is not in the standby state A communication interface device, comprising: a control unit that gives an instruction to output a service tone. 2. The data communication device further comprises hook detection means, wherein the control means indicates that communication is disabled when the control means is judged to be in a standby state and the hook detection means detects an off-hook of the data communication device. 2. The configuration as instructed to output a service tone.
The communication interface device described. 3. A communication interface device for connecting a transmission line and a reception line of a mobile radio device to a wired public line terminal of a data communication device, wherein a service tone is connected to the wired public line terminal of the data communication device. Means, level detecting means for determining whether or not the carrier of the wireless channel in communication is at a level equal to or higher than a specified value at which communication is possible, and the service tone generating means when it is determined that the level is not equal to or higher than the specified value. And a control means for instructing to output a service tone indicating that communication is impossible.