GB2062410A

GB2062410A - Call barring arrangement

Info

Publication number: GB2062410A
Application number: GB7937037A
Authority: GB
Original assignee: Standard Telephone and Cables PLC
Current assignee: STC PLC
Priority date: 1979-10-25
Filing date: 1979-10-25
Publication date: 1981-05-20
Also published as: BR8006799A

Abstract

A selective call barring arrangement, for barring incoming calls in a telecommunication network, has at the premises of a subscriber with the facility a special terminal. When the subscriber wishes to bar incoming calls except from authorised callers, he sets a switch (SFS) from its normal N condition to its B condition in which call barring is in force. When an incoming call arrives, the caller receives a signal advising him to send his special signal. At the terminal this is detected by a decoder and the call indicated to the subscriber. The special signal can be sent from a hand-held coder (1, 2, 3), acoustically coupled for use to the caller's subset, or sent by dialling therefrom. The system is described as used with a conventional telephone answering machine.

Description

SPECIFICATION Call barring arrangement This invention relates to a selective call barring arrangement for use in a telephone network, especially (but not exclusively) in a public telephone network.

Some telephone subscribers feel a need for privacy in that they would prefer not to receive incoming calls, or to recieve them only from selected callers. This need may be continuous or may only be felt at certain times when the subscriber does not wish to be disturbed. Hence an object of the invention is to provide a selective call barring arrangement.

According to the present invention, there is provided a selective call barring arrangement for an automatic telecommunications system, in which each subscriber with the call barring facility is provided with a special terminal to which the line from the exchange is connected when the facility is in use, in which a said terminal includes means responsive to the reception of an incoming call indication when that terminal is idle to send to the caller a signal or a recorded announcement to indicate that call barring is in use, in which in response to such a signal or announcement the caller sends an authorisation signal allotted to him by the subscriber for whom the facility is in use, and in which in response tothe reception of a said authorisation signal the called subscriber's terminal responds to indicate to the called subscriber that there is an incoming call from an authorised subscriber.

Such an arrangement can be used in conjunction with a telephone answering machine, and it is in fact so used in the embodiment of the invention to be described herein. The arrangement permits the subscriber with the call barring facility to ensure that his telephone does not respond to calls except from authorised person. As an extension to this, provision can be made for the caller's identity to be announced to the protected subscriber, who then decides whether or not to accept the call.

An embodiment of the invention will now be described with reference to the accompanying drawing, which is a-simplified block diagram of a system in which the arrangement of the invention is used. This drawing is also, in effect, a flow diagram explanatory of the system's operation.

The method used is based on a simple remote control system operable over speech circuits of any length. Each authorised caller has a pocketsized coder and signals from which can be coupled, acoustically in the present case, into the telephone system at any instrument, and provides a few codes recognizable only by complementary apparatus at the protected subscriber's premises.

Such a pocket coder can, by the use of contemporary integrated circuit technology, be small and inexpensive.

When the subscriber with the call barring facility wishes to be protected, he operates a switch to divert his line from the normal subset to a special terminal. An incoming call is, after a short interval, automatically accepted by the special terminal and an intimation is given to the caller that the line is barred, but that it is prepared to accept a call from an authorised caller. This intimation is in the present case a recorded announcement, but a coded tone is a possible alternative. On reception of such an intimation, an authorised user, who possesses the necessary coder and the correct code signal couples his coder to the system and sends the code using a keyboard on the coder. This code on reception at the called line unlocks the access to the subset so that the telephone is rung.This code can, if desired, be individual to the caller, in which case his identity is announced to the called party's via his line. Another possibility here is for the caller to follow the initial code (indicating that he is an authorised user) by a second code, individual to himself, which causes the caller's identity to be indicated to the called party, who then decides whether or not to accept the call.

A possible simplification of the system is that, in response to the "line barred" indication the caller sends the code or codes referred to above by direct dialling or keying from the telephone instrument. This is possible in systems where a register recall faulty or its equivalent is provided.

When a conversation involving a protected subscriber has ended, the terminal automatically reverts to its "protected on hook" state, as it would after a pre-set time if the subscriber decides not to answer, or if the terminal does not receive an "authorised" code. In emergency the system can be over-ridden by the telephone operator sending the correct access code.

A variant of the above is useful to disabled people who are temporarily left alone and found it difficult or impossible to get to or lift a conventional handset. Incoming calls from authorised users would after acceptance, which sounds an alert signal, be transferred to a loudspeaking or cordless telephone.

In the accompanying drawing, we see the remote instrument in the upper part, plus the portable coder, which includes a keyboard 1 connected via a coder to an acoustic coupler 3, which is in effect a small loudspeaker. To send a code the user places this coupler adjacent the microphone of the telephone subset. In view of the nature of the drawing, i.e. as it is in effect a combination of a block diagram and a flow diagram, only a fairly brief description is needed.

When the called subscriber does not wish to be disturbed he sets his function switch SFS from its N state in which it is connected to the normal subset 4 to its B position, which is the call barred condition. Note that if he does not wish to receive any calls, or if he leaves the premises, he sets the switch to its A position, which then provides conventional answering machine operation.

A caller dials in the usual way, and after a few rings he hears a recorded announcement which says: "This is the Bloggs residence: when you hear the tone please dictate your message or transmit your key signal".

The caller then hears a short burst of tone, and if he is not an authorised user (i.e. does not have a coder or does not know the access code) he merely leaves a recorded message. The called subscriber does not know that he has been called until he plays the tape back.

If the caller is an authorised user, he attaches the acoustic coupler of his coder and keys in a code peculiar to the subscriber, whereafter he listens to the earpiece. If the code is valid, the caller subscriber hears an alarm signal, which is also sent to the caller as a "ringing" signal. If the called subscriber wishes to accept the call he resets his switch SFS to its N condition and offhooks in the usual way.

If the called subscriber does not wish to accept the call, he merely ignores the call and after, say, 30 seconds it stops and either the call is terminated, or the caller hears another recorded announcement: "Mr. Bloggs is not available: when you hear the tone, please dictate a message".

Thus in the latter case the system reverts to normal answering machine operation.

In a system in which each potential caller has a personal code individual to him, this could be sent as mentioned above after the first "authorised user" code, which could bring up the caller's identity on a visual display device. The decoder in the special terminal can also be made to sound the alarm only if the caller is acceptable so that the called subscriber can decide which of the normally authorised callers he is prepared to accept.

Note that the incoming call can be answered by a coded tone and not by a recorded announcement if the answering machine facility is not needed. Also as mentioned above, the codes to be sent by callers could be sent by the dial or keypad of the telephone instrument he is using.

This would follow techniques used for such functions as "register recall" and would avoid the need for a special device for each authorised user.

Claims

1. A selective call barring arrangement for an automatic telecommunication system, in which each subscriber with the call barring facility is provided with a special terminal to which the line from the exchange is connected when the facility is in use, in which a said terminal includes means responsive to the reception of an incoming call indication when that terminal is idle to send to the caller a signal or a recorded announcement to indicate that call barring is in use, in which in response to such a signal or announcement the caller sends an authorisation signal allotted to him by the subscriber for whom the facility is in use: and in which in response to the reception of a said authorisaiton signal the called subscriber's terminal responds to indicate to the called subscriber that there is an incoming call from an authorised subscriber.

2. An arrangement as claimed in claim 1, and in which the authorisation signal is sent by the caller from a hand-held coder which is acoustically coupled to the user's telephone.

3. An arrangement as claimed in claim 1 or 2, in which the terminal can respond to a code additional to the authorisation signal which identifies the caller, and in which said identity is displayed visually at the receiving premises.

4. An arrangement as claimed in claim 1 or 2, in which each authorisation signal also identifies the caller, and in which in response to such a signal the caller's identity is displayed visually at the receiving position.

5. An arrangement as claimed in claim 1, 2, 3 or 4, and in which the special terminal also includes a telephone answering machine.

6. A selective call barring arrangement for use in a telephone switching network, substantially as described with reference to the accompanying drawing.