JP2024134630A - Public telephones and methods for preventing fraudulent use - Google Patents

Abstract

[Problem] To prevent unauthorized use of one-ring calls using public telephones, while allowing free calling services in emergencies to be used without hindrance. [Solution] An automatic answering machine is provided that automatically answers an incoming call. The public telephone is equipped with a memory unit that stores the telephone number of the automatic answering machine, a billing availability detection means that detects whether or not billing for the call is possible, and a means that, if the billing availability detection means detects that billing is not possible, makes a call using the telephone number of the automatic answering machine stored in the memory unit before making a call using the accepted destination telephone number. [Selected Figure] Figure 1

Description

This invention relates to a method for preventing fraudulent use of public telephones, known as one-ring calls, in which a call is made without inserting a coin or card and then the call is disconnected when the called party answers, and to a public telephone used in this method.

When using a public telephone to talk to someone, you lift the handset and go off-hook, then insert coins or a card and dial the other party's phone number. A dial signal for the other party's phone number is then sent to the line, and the other party is called. When the other party answers, the public telephone collects the call fee from the inserted coins or card at each charge. If the inserted coins or card run out of money, the public telephone forcibly disconnects the line and ends the call.

As described above, public telephones allow users to make calls on the premise that they are charged for the service, but there has been some fraudulent use of the service, whereby a user can make a free call by grounding one end of the handset connection cord while calling the other party and dialing a toll-free number. In order to prevent this fraudulent use, Patent Document 1 (JP Patent Publication No. 11-146097) has been proposed.

Although this is not an illegal use of free calls, there is also the illegal use of public phones where a call is made without inserting coins or a card, and when the other party answers, a call is forcibly disconnected by receiving a response reception signal from the switchboard, resulting in the so-called one-ring call. Because one-ring calls are free of charge, they are often used illegally for the purpose of harassment, by making multiple one-ring calls to the other party, and this has become a problem.

The sequence for a one-ring call using this public telephone is explained using Figure 6.

When the handset is lifted and off-hooked, the public telephone closes a DC loop on the line between it and the exchange. Next, when the public telephone receives a push button press (dial input) of the other party's telephone number, it sends a PB (push button) signal to the exchange as a dial signal for the pressed number. Note that in the example of Figure 6, it is assumed that the user of the public telephone is entering the other party's telephone number without inserting any coins or a card.

The public telephone sends a PB signal for the number to the exchange each time the push button for the other party's telephone number is pressed. The public telephone continues this operation until the push button for the last number of the other party's telephone number is pressed (final dial input).

When the exchange receives a PB signal for the final number based on the final dial input of the destination telephone number from a public telephone, it receives the call by transferring the line to the telephone of that telephone number and sends a ringing signal. In response to the ringing signal, the telephone rings to notify the user of the incoming call. When the user of the telephone goes off-hook in response to the ringing, for example by lifting the handset, a DC loop is closed on the line between the telephone and the exchange.

When the exchange confirms that the DC loop between the other party's telephone and the exchange is closed, it sends a response receipt signal to the public telephone. This response receipt signal is a response signal that conveys the other party's response to the public telephone, and is also a billing signal that instructs the billing process, i.e., to collect the inserted coins or to collect the telephone charge from the card.

When the public telephone receives the answer reception signal from the exchange, if coins or a card are inserted, it carries out the billing process, but if no coins or card are inserted, it performs a forced disconnection operation and opens the closed DC loop of the line between the public telephone and the exchange. The exchange then disconnects the call and sends out a disconnection signal and a busy tone. As a result, the line is disconnected even though the other telephone has answered by going off-hook, resulting in what is known as a one-ring call.

As is clear from the sequence in Figure 6, with conventional public telephones, even if no coins or cards are inserted, a call can be received at the other party's telephone, and when the other party answers, the call is forcibly disconnected because no coins or cards are inserted, making it possible to make the so-called one-ring call free of charge.

Japanese Patent Application Publication No. 11-146097

Conventionally, there have been technologies such as those described in Patent Document 1 that have been used to prevent free calls made through special fraudulent operations as described above, but no means have been provided to solve the problem of preventing the above-mentioned one-ring calls.

As a countermeasure against the one-ring calls mentioned above, one possible method is for the calling public phone to check that coins or a card are inserted at the latest before the final dialing operation for the recipient's telephone number is performed, and if it is not possible to confirm that coins or a card are inserted, it will forcibly disconnect the call. The sequence for this method is shown in Figure 7.

In Figure 7, up until the first dialing of the other party's telephone number, the sequence is exactly the same as the example sequence in Figure 6. In this example public telephone, as shown in the sequence in Figure 7, from the first dialing of the other party's telephone number until the final dialing of the other party's telephone number, a process is performed to confirm the number of digits dialed and whether or not coins or a card have been inserted.

If the public telephone does not confirm that coins or a card have been inserted, when it receives the final dial input, it will not send a PB signal for the final telephone number to the exchange, but will perform a forced disconnection and open the DC loop of the line between the public telephone and the exchange that was closed.

With a public telephone that performs the sequence shown in Figure 7, if no coins or cards are inserted, the call will not be received by the other party's telephone number, preventing the fraudulent use of the free one-ring calls mentioned above. However, with a public telephone that performs the sequence shown in Figure 7, there is a problem in that in the event of a major earthquake, for example, the free emergency call service provided by the telephone company cannot be received.

In other words, if a disaster occurs on a scale that applies to the Disaster Relief Act, such as a major earthquake, and a widespread power outage occurs, and the telephone company determines that it is necessary to ensure that disaster victims can make calls, calls from public phones can be made free of charge for a specified period of time during the emergency. This is because, during the specified period of time during the emergency, if a call is made from a public phone to the other party's phone number and the other party answers, the exchange does not send the response acceptance signal in the sequence of Figure 6 to the public phone, making it possible to talk to the other party even if no coins or cards are inserted.

However, if a public telephone is configured to perform the sequence shown in Figure 7, the call will be forcibly disconnected without making a call using the other party's telephone number, resulting in the problem that the free call service cannot be used even during the emergency period when the above-mentioned free call service is available.

The purpose of this invention is to provide a public telephone that can solve the above problems.

In order to solve the above problem, the invention of claim 1 comprises:
A storage unit for storing a telephone number of an automatic answering machine that automatically answers an incoming call;
a billing availability detection means for detecting whether or not billing for a call is possible;
means for making a call using the telephone number of the automatic answering machine stored in the storage unit before making a call using the accepted telephone number of the other party when the billing possibility detection means detects that the billing is not possible;
The present invention provides a public telephone comprising:

In the public telephone according to the invention of claim 1 with the above configuration, when it is detected that billing by coin or card is not possible, a call is made using the telephone number of the automatic answering machine stored in the memory unit before making a call using the accepted telephone number of the other party.

When a switchboard receives a call using the telephone number of this automatic answering machine, it allows the automatic answering machine to receive the call. The automatic answering machine then automatically answers the call, and the switchboard receives the automatic answer and sends a response acceptance signal to the public telephone. The public telephone receives this response acceptance signal and performs billing based on the inserted coins or card. If no coins or card are inserted and billing cannot be performed, the call is forcibly disconnected as explained in Figure 6. Therefore, if no coins or card are inserted and billing cannot be performed, no call is made using the accepted recipient's telephone number. This makes it possible to prevent one-ring calls.

In addition, if a disaster occurs on a scale that applies to the Disaster Relief Act, and public telephones are in an emergency period during which they can provide free telephone service, the exchange will not send a response accommodation signal based on an automatic response from an automatic answering machine. Therefore, public telephones can provide free telephone service without hindrance by making a call from the accepted telephone number of the other party after making a call to the automatic answering machine.

The public telephone of this invention can prevent unauthorized use of one-ring calls and can provide free telephone service in the event of a disaster of such scale that the Disaster Relief Act applies.

1 is a block diagram showing an example of the configuration of an embodiment of a public telephone according to the present invention; FIG. 2 is a diagram showing a part of a flowchart for explaining the flow of operations when making a call in an embodiment of a public telephone according to the present invention. FIG. 2 is a diagram showing a part of a flowchart for explaining the flow of operations when making a call in an embodiment of a public telephone according to the present invention. FIG. 13 is a diagram showing an example of a sequence for preventing unauthorized use of a one-ring call using an embodiment of a public telephone according to the present invention. FIG. 11 is a diagram showing an example of a sequence for receiving a free call service in an emergency using a public telephone according to an embodiment of the present invention. FIG. 1 is a diagram showing an example of a sequence in which a one-ring call is fraudulently used using a conventional public telephone; FIG. 11 is a diagram showing an example of a sequence for explaining an example of a method for preventing unauthorized use of one-ring calls on a public telephone.

Below, an embodiment of the method for preventing unauthorized use and a public telephone according to the present invention will be described with reference to the drawings.

<Overview of the embodiment of the fraud prevention method according to the present invention>
In an embodiment of the fraud prevention method according to the present invention, an automatic answering machine that automatically answers incoming calls is installed, and a specific telephone number is assigned to the automatic answering machine in advance. In this example, the telephone number assigned to the automatic answering machine is a telephone number for confirming whether or not it is an emergency period during which emergency free call services can be received. Note that the automatic answering machine does not need to have a telephone function for sending and receiving calls, and may be any type of device or equipment, as long as it has a function for automatically answering incoming calls. The telephone number assigned to the automatic answering machine may be a subscriber telephone number or a specifically specified telephone number.

In an embodiment of the fraud prevention method according to the present invention, the public telephone has a dial input storage function that accepts the input of the other party's telephone number after going off-hook and temporarily stores the accepted telephone number, and a billing availability detection function that detects whether or not the telephone call can be charged based on whether or not coins or a card are inserted while the input of the other party's telephone number is being accepted. If the billing availability detection function of the public telephone detects that no coins or a card have been inserted and that the telephone call cannot be charged, the public telephone dials the telephone number of the automatic answering machine before dialing the other party's telephone number.

The auto-answering machine then automatically answers the call from the public phone. When the switching system receives the auto-answering machine's response, it determines whether or not it is an emergency period during which free emergency call services are available, and if it is not an emergency period, it sends a response accommodation signal to the public phone. The public phone receives this response accommodation signal and attempts to start charging, but since no coins or cards have been inserted and charging is not possible, it forcibly disconnects the line and releases it. This prevents the other party from dialing out, preventing one-ring calls.

On the other hand, if it is an emergency period during which free emergency call services are available, the switchboard will not send a response accommodation signal in response to the automatic answering machine's automatic response. For this reason, in the public telephone of this embodiment of the invention, even if the call is in a non-billing state, the call will not be forcibly disconnected, but will be dialed to the telephone number of the other party that has been accepted. This makes it possible to accommodate free emergency call services.

<Embodiments of public telephones according to the present invention>
1 is a block diagram showing an example of the configuration of a public telephone 1 according to an embodiment. In the public telephone 1 of this embodiment, a telephone transmitting/receiving circuit 11 is connected to lines L1 and L2, and a handset 12 is connected to the telephone transmitting/receiving circuit 11. The telephone transmitting/receiving circuit 11 is also connected to a control circuit 10, which controls the entire public telephone 1 and is formed of, for example, a computer.

The control circuit 10 is connected to a hook switch 13, an operation unit 14, a display unit 15, a dial circuit 16, a billing processing unit 17, an automatic answering machine telephone number storage unit 18, and an announcement voice storage unit 19.

The hook switch 13 goes off-hook when the handset 12 is lifted, and goes back to on-hook when the handset 12 is replaced. The control circuit 10 constantly monitors the state of the hook switch 13.

In this example, the operation unit 14 is equipped with a group of push buttons as a means for inputting a telephone number. The control circuit 10 has the function of detecting which of the push buttons of the operation unit 14 has been pressed, and detecting the dialing of a telephone number.

The display unit 15 displays the entered telephone number and other displays based on display control from the control circuit 10.

The dial circuit 16 generates a PB signal for the telephone number received through the operation unit 14 based on control from the control circuit 10, and sends it to lines L1 and L2.

The billing processor 17 has a mechanism for receiving coins and cards, and performs billing for telephone charges under the control of the control circuit 10. In this example, the billing processor 17 has a function for transmitting a notification to the control circuit 10 when it has confirmed that coins have been inserted or that a card has been inserted.

In this embodiment, the control circuit 10 has a billing feasibility detection function that detects whether or not the call charge can be billed before all digits of the telephone number are input through the operation unit 14 by monitoring the confirmation notification of the insertion of coins or a card from the billing processing unit 17.

The auto-responder telephone number storage unit 18 stores the telephone numbers assigned to the auto-responders described above. When the control circuit 10 detects, by the billing possibility detection function, that the call charge is not billable, it reads out the telephone number of the auto-responder stored in the auto-responder telephone number storage unit 18 before dialing the other party's telephone number, and dials the telephone number.

The announcement voice storage unit 19 stores an announcement voice message that alerts the user of the public telephone to the delay time caused by dialing an automatic answering machine when the billing possibility detection function of the control circuit 10 does not allow billing of the call fee. When dialing an automatic answering machine, the control circuit 10 reads out the announcement voice message from the announcement voice storage unit 19 and allows the user of the public telephone to hear it. In this example, this announcement voice message is something like "We are checking the emergency period. Please wait a moment," and is intended for users of emergency free calls during large-scale disasters when free calling services are available.

<Example of operation when calling from public telephone 1>
An example of the operation of the public telephone 1 of the embodiment configured as above when making a call will be described with reference to Fig. 2 and the subsequent flow chart of Fig. 3. In the following description, the process of each step of the flow chart of Fig. 2 and Fig. 3 will be described as being executed by the control circuit 10 configured as a computer by a software program.

The control circuit 10 monitors whether the handset 12 of the public telephone 1 has been lifted and taken off-hook (step S101). If it is determined in step S101 that the handset has been taken off-hook, the control circuit 10 closes the DC loops of the lines L1 and L2 (step S102), accepts dial input (telephone number input) by the user of the public telephone 1 via the operation unit 14, and accumulates the input in the buffer memory sequentially for temporary storage (step S103).

Then, the control circuit 10 determines whether or not the final dial input (the input of the last phone number) has been temporarily stored (step S104), and if it determines that the temporary storage of the final dial input has not been completed, it returns to step S103 and accumulates the received dial inputs in sequence and temporarily stores them in the buffer memory.

When it is determined in step S104 that the final dial input has been temporarily stored, the control circuit 10 determines whether or not coins or a card have been inserted based on a notification from the billing processing unit 17, and determines whether or not billing is possible (step S105).

If it is determined in step S105 that coins or a card have been inserted and that billing is possible, the control circuit 10 dials the other party's telephone number that was stored in the buffer memory in step S103 (step S106). The control circuit 10 then performs the normal routine that follows dialing the other party's telephone number, and creates a call path if the other party answers.

If it is determined in step S105 that no coins or cards have been inserted and that the telephone is not in a state where billing is possible, the control circuit 10 reads the telephone number of the auto-responder from the auto-responder telephone number storage unit 18 and performs an automatic dialing call (step S107). At this time, the control circuit 10 mutes the dial tone (PB tone) during this automatic dialing call so that the user of the public telephone does not hear the dummy dialing tone.

Then, the control circuit 10 reads out from the announcement voice storage unit 19 a voice message to alert the user of the public telephone to wait for the delay time caused by the dummy call to the automatic answering machine, and in this example, plays the message through the handset of the handset 12 (step S108).

Next, the control circuit 10 waits to receive a signal from the exchange (step S109), and when it confirms that a signal has been received from the exchange, it performs a dummy disconnection in response to the dummy call made in step S107 (step S111 in FIG. 3). Then, the control circuit 10 determines whether or not a response collection signal has been received as a signal from the exchange (step S112).

If it is determined in step S112 that a response hang-up signal has been received from the exchange, the control circuit 10 performs a forced disconnect (step S113), opens the DC loop, and transmits a busy tone through the handset 12. The control circuit 10 then determines whether the handset 12 has been replaced and is now on-hook (step S116). If it is not on-hook, the control circuit 10 returns to step S115 and continues transmitting the busy tone; if it is determined that it is on-hook, the control circuit 10 stops the busy tone (step S117) and ends this processing routine.

As described above, when it is determined in step S105 that no coins or cards have been inserted and billing is not possible, and when it is determined in step S112 that a response receipt signal has been received from the exchange, the call is forcibly disconnected without dialing the stored telephone number of the other party, thereby preventing unauthorized use of one-ring calls.

In addition, during an emergency period when a free call service is provided, the switchboard does not send a response collection signal. In this case, the control circuit 10 determines in step S112 that a response collection signal has not been received, performs a dummy disconnection with the automatic answering machine that automatically responded to the dummy call, and opens the DC loops for lines L1 and L2 between the switchboard and the switchboard (step S118). The control circuit 10 then recloses the DC loops on lines L1 and L2 (step S119) and dials the other party's telephone number that was stored in the buffer memory (step S120). The control circuit 10 then performs the normal routine after dialing the other party's telephone number to create a communication path between the other party and the switchboard.

As described above, if it is determined in step S105 that no coins or cards have been inserted and billing is not possible, and if it is determined in step S112 that there is no response receipt signal from the exchange (if an emergency period is occurring), the stored telephone number of the other party is dialed, a call path is created, a call can be made, and the free call service can be received.

<Example of a sequence for fraudulent use with the intent of one-ring calls>
FIG. 4 shows an example of a sequence for preventing unauthorized use of the public telephone 1 described above with the intention of making a one-ring call.

In this case, the user lifts the handset 12 to go off-hook, and enters the other party's telephone number without inserting coins or a card. The public telephone 1 detects the off-hook and closes a DC loop on the line to the exchange. Next, each time the push button for the other party's telephone number is pressed (dial input), the public telephone 1 stores the pressed number in the buffer memory. While storing this dial input, the public telephone 1 detects whether coins or a card have been inserted.

When the push button for the final number of the other party's telephone number is pressed (final dial input) and the number is stored, in this example, public telephone 1 detects that no coins or card have been inserted and that the call is not billable. Based on this detection that billing is not possible, public telephone 1 dials the automatic answering machine (a dummy call). The dialing sound during this dummy call is muted, and in this example, a voice message is announced encouraging the caller to wait to confirm whether or not the call is in an emergency period.

When the exchange receives a PB signal from a public telephone to dial an automatic answering machine, it transfers the line and sends a ringing signal to the automatic answering machine to receive the call. The automatic answering machine automatically answers the call, and the response is sent to the exchange.

When the switchboard confirms a response from the automated answering machine, if it is not an emergency period, it sends a response receipt signal to public telephone 1.

When public telephone 1 receives the answer reception signal from the exchange, it performs a forced disconnection operation because no coins or cards have been inserted, and opens the closed DC loop of the line between the public telephone and the exchange. Public telephone 1 then emits a busy tone through the handset of handset 12.

As a result, the call is forcibly disconnected without dialing the other party's telephone number accepted by public telephone 1, preventing one-ring calls.

<Example of sequence for emergency free call>
Next, an example of a sequence when the above-described public telephone 1 is used for an emergency free call is shown in FIG.

In the example of Figure 5, the user also lifts the handset 12 to go off-hook, and enters the other party's telephone number without inserting a coin or a card. In the sequence example of Figure 5, the sequence from when the public telephone 1 detects the off-hook, to when the automatic answering machine automatically responds to the dummy dialing and sends the response to the exchange, is exactly the same as the sequence example of Figure 4.

In the sequence example of Figure 5, the exchange recognizes that it is in an emergency period, so in response to the response from the automatic answering machine, it responds to the public telephone 1 without including a response reception signal. For this reason, the public telephone 1 performs a dummy disconnection between itself and the automatic answering machine that automatically responded to the dummy call, and opens the DC loops for lines L1 and L2 between itself and the exchange. It then recloses the DC loops on lines L1 and L2, and dials the other party's telephone number that was stored in the buffer memory.

As shown in the sequence in Figure 5 above, the public telephone of the embodiment allows users to receive free call services in emergencies.

As described above, the method for preventing fraudulent use according to the present invention allows an automatic answering machine to be installed without making any changes to the exchange, and by configuring a public telephone set so that when it is in a state where billing is not possible, it dials the automatic answering machine before dialing the accepted telephone number of the other party, it is possible to prevent one-ring fraudulent use and also to accommodate free calling services in emergencies.

Reference Signs List 1: Public telephone, 10: Control circuit, 11: Telephone transmission/reception circuit, 12: Handset, 13: Hook switch, 14: Operation unit, 15: Display unit, 16: Dial circuit, 17: Accounting processing unit, 18: Automatic answering machine telephone number storage unit, 19: Announcement voice storage unit

Claims (6)

A storage unit for storing a telephone number of an automatic answering machine that automatically answers an incoming call;
a billing availability detection means for detecting whether or not billing for a call is possible;
means for making a call using the telephone number of the automatic answering machine stored in the storage unit before making a call using the accepted telephone number of the other party when the billing possibility detection means detects that the billing is not possible;
A public telephone comprising: 2. The public telephone according to claim 1, characterized in that, when a response receipt signal is detected from an exchange after a call is made using the telephone number of the automatic answering machine stored in the memory unit, the call is forcibly disconnected without making a call using the accepted destination telephone number. 2. The public telephone according to claim 1, characterized in that if a response receipt signal from a switching system is not detected after a call is made using the telephone number of the automatic answering machine stored in the memory unit, a call is made using the accepted destination telephone number. 2. The public telephone according to claim 1, wherein a dial tone is muted when a call is made using the telephone number of the automatic answering machine stored in the memory unit. 2. The public telephone according to claim 1, wherein after the call is made using the telephone number of the automatic answering machine stored in the memory unit, a voice message is sent out to alert the caller to wait. Install an automatic answering machine that automatically answers incoming calls.
A method for preventing fraudulent use, comprising the steps of: when a public telephone is not in a state in which billing for a call is possible, making a call using the telephone number of the automatic answering machine before making a call using the accepted destination telephone number.

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