JPS60172873A - Limit incoming system - Google Patents

Abstract

PURPOSE:To allow only an incoming call from a desired party by an incoming side subscriber by installing an adaptor corresponding to a subscriber of an incoming side subscriber line exchange and allowing the adaptor to receive and collate ciphered information inputted from an outgoing subscriber in the tentative respnse state at incoming call. CONSTITUTION:The ciphered information comprising dial signal (PB signal) of a pushphone transmitted from the outgoing telephone set 1 is transmitted to the adaptor (ADP) 6, received by a PB signal receiver 7 and its output is transferred to a CPU13. The ciphered information to select an opposite party allowing the incoming call registered in advance by the incoming subscriber is stored in a memory 14. The CPU13 compares the ciphered information transferred from the PB signal receiver 7 with the ciphered information stored in the memory 14 and when the both are coincident, it is regarded as an incoming call from the opposite party allowing the incoming call for the incoming subscriber, a relay A17 is activated, the contact (a) is driven downward, a call signal is transmitted to the incoming telephone set 24 from a call signal transmission circuit 15, then an output 20 of the CPU13 activates a call tone transmission circuit 10 so as to transmit the call tone to the outgoing side.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a limited incoming call system that allows incoming calls only from parties to whom the called subscriber has previously given encryption information.

Background of the Technology Currently, telephones are widely used as a convenient means of daily communication, but in conventional telephone services, the existing telephone network basically connects the call path to the number specified by the calling subscriber. Since the calling party cannot select the calling party, priority is given to the calling party.

Prior Art and Problems In conventional telephone services that give priority to the calling party, once the calling subscriber specifies the other party, the called party can pick up the phone at any time, except when the call is interrupted. However, there was an inconvenience in that it was impossible to confirm the identity of the person on the other end of the call unless the person on the other end of the line announced his or her name, and it was not possible to select the person on the other end of the call and not to ring or answer the call.

To solve this problem, it would be great if the calling party could know the identification information of the calling party when a call is received.

To do this, it is necessary to transfer the calling party identification information from the calling party to the receiving party before starting a call, but existing telephone networks do not have this function.

Purpose of the Invention The present invention installs an additional device corresponding to the subscriber terminal of the destination subscriber line exchange, and verifies the encrypted information input by the originating subscriber in a provisional response state at the time of receiving a call with the additional device. The purpose of this system is to provide a system that allows the receiving subscriber to receive calls only from the desired party.
The drawings will be explained in detail.

Embodiment of the Invention FIG. 1 shows an embodiment of the present invention, which is implemented by installing an additional device (hereinafter referred to as ADP) 6 corresponding to the destination subscriber terminal 4 of a subscriber line switch (hereinafter referred to as LS) 3. This shows the case where Note that in an actual telephone network, a trunk exchange may be inserted between the originating and terminating LS, but in the subscriber line, there is no change in the operational sequence, so here, the originating telephone 1 and the terminating telephone 24 are accommodated in the same LS. Let's explain the case where it is.

The originating subscriber line 2 and the terminating subscriber wj5 in Figure 1 are usually composed of two wires, and the DC voltage conditions of the two wires depending on the connection state are shown in Figures 2 (a) to (e). This is a guide to show. That is, in the normal state before a call is made in FIG. 2(a), Ll is at 100V and L2 is at 148V on both the originating and destination sides.

In Figures 2 (a) to (e), 1 indicates the connection of the telephone on the calling side, 24 indicates the connection of the telephone on the receiving side, the solid line connection between LX and L2 indicates that the handset is OFF, and the dotted line connection indicates that the handset is ON. Indicates the condition. In addition, Fig. 2 (b) shows the intention to make a call,
(C) shows the DC voltage conditions of the subscriber lines L1 and L2 in the respective states where a dial signal is being sent, (d) is in the middle of a call, and (e) is in the middle of a call.

In Figure 1, after off-hooking the originating telephone 1, when dialing the telephone number of the terminating telephone 24, the Ls3 sends a ring tone to the originating party, a ringing signal to the terminating party, and joins the terminating party. The polarity of the main line 5 is reversed, Ll is -48V,
L, 2 is tenchi ki naru (IPf-chu Figure 2 (d)).

Up to this point, there is no difference from the connection operation of a conventional telephone.

When the incoming call detection circuit 8 of the ADP 6 detects this inversion, the output 19 of the incoming call detection circuit 8 notifies the CPU 13 of the incoming call, and the provisional response circuit 9 creates a one-way loop in which current flows only in the direction from L2 to L1. A tentative response is made by forming . The inversion detection in the incoming call detection circuit 8 can be easily realized using, for example, a general-purpose comparator circuit, or a method may be adopted in which the call signal sent from the LS 3 is detected simultaneously with the inversion. The temporary response circuit 9 can be easily constructed by, for example, a diode that allows current to flow in the direction of L2→L1, a series resistor, and the like. Furthermore, by combining a phototransistor or the like with a diode and series resistor configuration that allows current to flow in the direction of L2→L1, it is also possible to realize both the functions of the temporary response circuit 9 and the incoming call detection circuit 8 at the same time. .

Provisional response is a technology implemented in the trunks for toll-free incoming calls in existing telephone networks, and the calling subscriber is not charged, thereby preventing losses on the calling side. This is an existing, well-known technique, and a detailed explanation will be omitted here, but in the state after the provisional response, the DC voltage condition of the subscriber line is as shown in Figure 2 (
In the same state as a) to (c), with the ring tone and ring signal stopped and billing not started, calling telephone 1 and AD
A communication path is formed with P6.

The outline of the tentative response operation has been explained above, but since the actual operation is executed almost instantaneously, the time it takes for the ringing tone and ringing signal to be sent from the LS3 to the calling telephone 1 and the receiving telephone 24, respectively, is very short. , is actually close to 0, so the calling telephone 1 can hardly hear the ringing tone sent from the LS3. In the above explanation, an example was explained in which the calling subscriber is not charged at the time of a provisional response, but if a two-way loop (the same loop as the conventional call response) is created in the provisional response circuit 9, charges are not incurred from the time of the provisional response. It is also possible to do so.

When the CPU 13 is notified of the incoming call by the output 19 of the incoming call detection circuit 8, the CPU 13 operates the guidance sending circuit 12 by the output 22 of the CPU 13, and sends a guidance requesting input of encrypted information from the ADP 6 to the calling telephone 1. Send out. The guidance sending circuit 12 includes, for example, a voice synthesis L
This can be easily realized using an SI or the like, or an IC or the like that creates a tone signal within the voice band may also be used.

The originating subscriber listens to the guidance and enters encrypted information. The specific means (signal) used to input the encrypted information may be anything as long as it can be transmitted within the voice communication band of the telephone, but for example, a telephone dial signal (
(hereinafter referred to as PB double signal), etc. may be used as is. The following will explain the case of a PB double signal as an example. As the encrypted information, for example, a four-digit number such as that used in automatic cash payment services of banks can be used. To input the PB double signal, if the calling telephone operator is a butshu phone, simply press the dial button, or if the phone is a dial pulse phone, press the portable acoustic double PB transmitter against the transmitter. May be used.

The encrypted information based on the PB double signal sent from the calling telephone 1 is transferred to the ADP 6 and received by the PB signal receiver 7.
The output of the PB signal receiver 7 is stored in the CPU 13 with cryptographic information for selecting a party to whom incoming calls are permitted. The CPU 13 compares the encrypted information transferred from the PB signal receiver 7 with the encrypted information stored in the memory 14, and if the two match, the receiving subscriber accepts the call from the other party. Regarded as incoming call, relay A
17 to drive the contact a downward to send a ringing signal from the ringing signal sending circuit 15 to the destination telephone 24, and at the same time, the output 20 of the CPU 13 operates the ringing sound sending circuit 10 to generate a ringing sound. Send it to the side.

The called telephone 24 receives the calling signal and rings the bell. When the called subscriber goes off-hook and responds, the subscriber response detection circuit 16 detects this, and the subscriber response detection circuit 16
The subscriber response is notified to the CPU 13 by the output 23 of the p CPU 13. In response to this, the CPU 13 deactivates relay A 17 Q, restores contact a, stops sending out the discharge signal, and creates a bidirectional loop (the same loop as the conventional incoming call response) in the destination subscriber line 5. At the same time, the output 20 of the CPU 13 stops the operation of the ring tone sending circuit IO.

When a loop is created in the terminating subscriber line 5, the polarity of the originating subscriber line 2 is reversed and Ll is 14 as shown in FIG. 2(e).
At 8v, L2 becomes 10-chi-ki and billing starts, and at the same time, a call becomes possible between the calling-side telephone 1 and the called-side telephone 24.

If the encrypted information transferred from the PB signal receiver 7 to the CPU 13 by the output 18 of the PB signal receiver 7 and the encrypted information stored in the memory 14 do not match, an incoming call is received from a party that the called party does not accept. Based on the output 21 of the CPU 13, the busy tone sending circuit 11 is operated to send a busy tone to the calling party, and no calling signal is sent to the receiving telephone 24. Note that the busy tone when incoming calls are not permitted may be a system in which the guidance sending circuit 12 sends a message such as ``You cannot connect to this subscriber'' (for example, by voice).

As explained in detail in the software invention, the series of control operations described above can be performed by installing additional devices corresponding to the subscriber terminals of subscribers who desire all the services of the existing telephone network. , it will now be possible to only accept incoming calls from the party the called party desires, so it will be possible to quickly and easily provide services in which the called party has the right to choose, instead of the telephone service that had previously given priority to the calling party. It can be provided without making large-scale modifications to the existing telephone network. Moreover, since the PB double signal is used for the encrypted information for selecting the called party, the calling subscriber can directly send the encrypted information from a normal push-button dial telephone, such as a push-button dial public telephone, even when away from home. It is possible to realize a system with good service performance for side subscribers as well. By implementing the present invention, a significant effect can be expected in preventing intimidation and harassing phone calls that abuse the telephone service that gives priority to the calling party. In addition, by applying it to telephones within a specific company, it is possible to create a kind of closed communication area using the public telephone network.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing the connection operation of a subscriber line exchange. 1... Calling side telephone, 2... Calling side subscriber line, 3...
Subscriber line switch (LS), 4... Destination subscriber terminal, 5
...Destination subscriber line, 6...Destination side additional device (ADP)
, 7... PB signal receiver, 8... Incoming call detection circuit, 9
...Temporary response circuit, 10...Ring tone sending circuit, 11.
...Busy tone sending circuit, LE...Guidance sending out path, 13...CPU, 14...Memory, 15...
Calling signal sending circuit, 16...Subscriber response detection circuit, 1
7... Relay A, 18... Output of PB signal receiver 7, 19... Output of incoming call detection circuit 8, 20-22...
Output of CPU 13, 23...Subscriber response detection circuit 16
Output, 24...Destination telephone. Patent applicant Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] In the automatic telephone switching system 1, means for registering and storing cryptographic information in advance for allowing the receiving subscriber to receive a call, means for detecting the received call, and means for detecting the received call, corresponding to the subscriber terminal of the receiving subscriber line exchange. The p-originating subscriber forms a loop with the output of the means and tentatively responds. provisional response means for setting up a communication path between the sender and the sender; and means for receiving encrypted information transferred from the originating side after the provisional response means sets up the communication path.
means for comparing said received encrypted information with said pre-registered and stored encrypted information; 1. A limited call termination system, characterized in that it comprises an additional device having means for connecting both subscribers on the destination side.