GB2305329A - Telecommunication system - Google Patents

Abstract

A telephone (1) is provided with a component (2) arranged to detect the Calling Line Identification (CLI) signal in an incoming call. The CLI signal is fed to a comparator (3) which compares the CLI signal with a list stored in a memory (4). If the comparator (3) finds a match with the list in the memory (4), an audible indicator (5) is operated by a sound signal generator (6) to provide an audible indication associated with the matched listed number. If no match is detected, the sound signal generator (6) is arranged to operate the audible indicator (5) with a default ringing cadence which conveniently can be the native cadence supplied by the telephone network. The invention enables information about an incoming call to be stored, such as the number of the intended Answerer, the reason why the call has been diverted to the present number and, when available, the telephone number of the Caller. This information is then transmitted in audible form to the eventual Answerer when the appropriate telephone is answered, whilst at the same time giving the Caller a ringing tone, the Caller/Answerer connection only being made either when the audible information is complete and/or the Recipient is ready to accept the call.

Description

Telecommunications Systems This invention relates to telecommunications systems, and concems in particular enhanced services provided to people receiving telephone calls.

When a telephone rings, little information is generally provided about the call, and much is left to be established from the conversation with the Caller. However, in a world in which the impression created in responding to a telephone call is increasingly commercially important, prior information may allow the person called to respond in a different way - or indeed they may choose not to respond at all. This invention concerns ways of forwarding additional, prior information.

Recently, telephones have appeared with a liquid crystal display, that can give certain additional information about an incoming call. Typically this information may be the number of the telephone at which the call originated. This information is often made available by public networks - British Telecom, for example - though transmission may be suppressed by the Caller.

This information is known as Calling Line Identification (CLI), and is sent as a burst of digital data immediately prior to the ringing signal.

In a similar fashion, in cases where the telephone is capable of ringing in response to several dialled telephone numbers - for example an operator position -, the display may show the number that was dialled to cause the telephone to ring. This type of information is typically provided on digital lines as addressing information within the signalling packet. For example, ISDN Basic Rate Access provides for eight different dialled numbers to cause the line to ring.

This is known as Multiple Subscriber Numbering (MSN); it is often used to determine which of a number of telephone instruments connected to the ISDN line will ring.

On private lines connected to a local private branch exchange (PBX) switch, additional information which may be useful is generated by the switch and sent to the telephone. This information is typically provided as special signals down a second pair of wires from the private switch.

Now, whereas a display on a telephone providing this additional prior information is useful if you happen to be sitting in front of it, it is less satisfactory if you are some distance away, and unable to read the display. In this case, an audible indication would be more satisfactory; this invention relates to the provision of such an audible indication.

More specifically, the invention provides two ways in which additional information about the telephone call may be given audibly, before the Caller and the person being called are put in direct communication. One of these methods applies before the telephone handset is picked up. The other applies afterwards, but before the personal speech path is established.

The first of these methods is now described.

Before being answered, a telephone may be programmed to provide an audible indication of information available to it concerninglfie arriving call. This is most readily achieved by modifying the ringing indication. (This may, for example, be used to differentiate an incoming personal call from a business one.) In public and most private telephone networks, the arriving ringing indication comprises a 25Hz alternating signal, interrupted with a characteristic cadence. In modem telephones, this is used to power and interrupt an integrated circuit that generates a modulated high pitch signal, and this in turn drives an electromechanical sounder (loudspeaker or piezoelectric element), to give the ringing noise.

The invention proposes that the telephone be modified to allow the manner in which this 25Hz signal is applied to be changed, so generating a different ringing noise, depending upon the originating number disclosed in the CLI signal. In one aspect, therefore, the invention provides a telephone containing: A memory that can store one or more numbers representing a likely calling number, CLI receiving means and a means of comparing this with the stored CLI numbers, outputting a distinctive signal or software message, dependent on whether a match is made, and with which of the stored numbers the match is made, and Ringing noise generating means that is controllable in response to the CLI recognition and comparison means output to create a ringing noise representative of the calling number.

The variations which may be applied to this indication to convey different types of call include variations in pitch or harmonic content, and additional interruptions in the ringing cadence. If it is desired to ignore certain telephone calls, the indication may be suppressed completely.

For example, the sounder may be driven by the output of one or more cyclic digital counters.

The reload values of these counters may be set according to the result of the comparison process, thus altering the pitch, harmonic content and/or interruption rate of the noise.

If a continuous source of power is available to the means of generating the sound, or the arriving ringing current is rectified and stored briefly in a capacitor or battery, completely different cadences may be generated. If it is necessary to differentiate a very large number of possible audible indications, a coding system similar to Morse Code or a selection of synthesised voice messages may be used.

An embodiment of this aspect of the invention is shown in the accompanying drawing. A telephone 1 includes a component 2 which is capable of detecting the Calling Line Identification (CLI) signal arriving with an incoming call. The CLI is fed to a comparator 3 which compares the CLI with a list stored in memory 4. If any match is found, the ringing indication associated with the list element is selected in the sound signal generator 6 and fed to the audible indicator 5. If no match is found, or no CLI was supplied, a default ringing cadence (perhaps the native one supplied by the telephone network) is connected to the audible indicator.

The programming of the memory 4 is achieved by pressing a special key or combination of keys on the telephone during or after a telephone call received from the required source. If the call is received from a telephone which for some reason does not send a CLI, an error indication is given, and no programming occurs. Less attractively, the CLI may be entered using the numeric keys on the telephone, but this requires the CLI to be known, and therefore probably also requires a display to display it.

The same approach but using a different form of incoming signal detector may be applied to a digital telephone to recognise the digital packet containing the CLI or the dialled destination number.

The second method is that of providing information after the handset has been picked up, but before a personal speech path has been established. It is now described in more detail: As telephone systems become increasingly sophisticated, the routing of calls can become very complicated. For example, it is now common practice for a telephone switching system -and particularly a private system (PBX) to be programmed so that if a particular telephone is not answered within a certain number of rings, or is busy, the call may be transferred to someone else. A user may also programme his telephone to divert all his calls to another telephone, which may in principle be anywhere in the world. Accidental diversion to a wrong number can leave a person completely incommunicado.

Where these practices become widespread, it is not uncommon for a person answering a call which has suffered more than one diversion to be quite unable to respond to the needs of the Caller. Indeed, in a large organisation, they may not even know the person who was originally called.

Clearly, it is desirable for a person who responds to a diverted call to be aware that it is a diverted call, and be aware of the circumstances that have caused the diversion. For example, their response should probably be different if the diversion was caused by the called person already being on the telephone, than if they have left their telephone permanently diverted.

Whilst some PBX telephone systems are now using the second pair of wires that connect to featurephones to provide information of this kind on a display on the telephone, this requires special telephones and four-wire connections. However, the method is quite unsuitable to diversions out to ordinary telephones on the public network. The invention proposes a different solution, being one in which the telephone system, typically a PBX, conveys this type of call source information.

In another aspect, therefore, the invention provides a telephone system that can store information about the call, such as the number of the intended Answerer, the reason the call has been diverted to this telephone, and optionally, if available, the telephone number of the Caller, and can transmit that information in audible form to the eventual Answerer when the appropriate telephone is answered, whilst at the same time giving the Caller a ringing tone, only making the actual Caller-Answerer connection when the audible information is complete and/or the Recipient signals a willingness to accept the call.

As the Caller will generally be hearing ringing tone during the diversion and message-giving, it is obviously desirable that the messages are concise.

Some possible messages are given by way of example.

Caller dialled 2345, but it is busy" Outside Caller dialled 2345, but that has diverted all calls to you" -This call was to 2345, diverted on no reply to 3456, which was busy" aCaller dialled 234567 The messages are assembled as needed from pre-recorded fragments. Optionally, peoples' names may be associated with extension numbers in a database in the telephone switch, and the messages may replace the number with the person's name. As text-to-speech conversion of proper names is unreliable (and sometimes comical), this will usually require the spoken names to be individually recorded.The first and last of the above examples might then become: Caller rang John Smith, but the line is busy" aCall for XYZ Engineering An altemative embodiment uses conventional data transmission technology (either modem modulation or d.t.m.f. dialling tones) to send this information in digital form from the telephone switch to the telephone instrument via the speech path (so-called -in-band signalling") in the few seconds immediately after the telephone is answered, with the demodulated data displayed on a display on the telephone. (In the event of uncertainty about the exact moment of answering the call, the information may be transmitted continuously, with a unique marker to indicate the start.) On receipt, the information may be displayed in written form, exactly as in the examples above, or a graphical representation of the routing of the call may be preferred.

Whilst this has the disadvantage of requiring a special telephone instrument in addition to a special telephone switch, the information can generally be conveyed to the Answerer more rapidly than a spoken message. It also potentially allows more comprehensive information to be given. For example, for a small telephone system with a small number of extensions or trunks, the status of all of the extensions or trunks could be included in the encoded information, rendering a remote keyphone system possible.

Claims (8)

Claims

1. A telephone instrument which is internally programmed to provide different audible indications, based on information provided by the equipment to which the telephone is connected concerning the telephone number that is the source of the arriving telephone call.

2. A telephone instrument which is intemally programmed to provide different audible indications, based on information provided by the equipment to which the telephone is connected concerning which of a predefined set of telephone numbers has been dialled.

3. A telephone switch which provides audible information conceming the origin of the call to the Answerer, prior to Answerer and Caller being connected together.

4. A telephone switch as in Claim 3, in which, before the incoming call is answered, the Answerer is given options for defining what now happens to the call.

5. A telephone switch as in Claim 3 or 4 in which the audible information is in the form of stored speech.

6. A telephone system comprising a telephone switch as in Claim 3 or 4 that is capable of transmitting as soon as the call is answered within the speech band in digitally encoded form the information concerning the origin of the call and optionally other status information, and a matching telephone instrument that is capable of decoding the data and providing the Answerer with a legible or graphic display of the information.

7. A telephone system as in Claim 6, in which the telephone instrument is capable of displaying the status of several or all of the other extensions or trunks on the system.

8. A telephone instrument, telephone switch or telephone system, substantially as described herein.