GB2381405A

GB2381405A - Interface which allows plural telephone sets connected to a shared line in a chained fashion to be individually accessed by different telephone numbers

Info

Publication number: GB2381405A
Application number: GB0122899A
Authority: GB
Inventors: James W H Churchman; Brian Gerard Docherty; Delme Thomas
Original assignee: SMALL PLANET TECHNOLOGY
Current assignee: SMALL PLANET TECHNOLOGY
Priority date: 2001-09-21
Filing date: 2001-09-21
Publication date: 2003-04-30
Also published as: GB0122899D0

Abstract

Telephone apparatus for enabling two or more ancillary telecommunications devices to be connected to a single telecommunications subscriber line which is accessible by means of at least two different telephone numbers. The telecommunications device is arranged to operate in one of at least two modes of operation, a first mode of operation causing the respective ancillary device to operate in response to the subscriber line being accessed by means of a first telephone number, and a second mode of operation causing the respective ancillary device to operate in response to the subscriber line being accessed by means of a second telephone number (different to the first). A slide switch is provided to enable the user to select the mode of operation of the device. The system allows telecommunications apparatus to be accessed individually when connected to the party line in a chained fashion, using distinctive ringing.

Description

TELECOMMUNICATIONS APPARATUS This invention relates to telecommunications apparatus and, more particularly, telecommunications apparatus including a control device for use in enabling the provision of plural telephone numbers on the same (i. e. a common) telephone line.

Telephone companies have, for many years, been providing a distinctive ringing service to their customers. Distinctive ringing is a feature or service which allows a single telephone line in, for example, a residence to be assigned more than one telephone number. In some prior art systems, this is accomplished in the central office of the telephone company, which utilises computer software to forward a specific ring cadence in response to a respective assigned telephone number. Thus, for example, a customer might request and be assigned a primary or"main"telephone number, a"teen line"telephone number and a"private line"telephone number, in which case, a different ring cadence is assigned to each number. If a caller dials the main telephone number, the customer's telephones will all ring as normal. If, however, the caller dials the teen line number, a different ring cadence is transmitted to the callers telephone causing it to ring with a different pattern, indicating that the teen line number has been dialled. Similarly, if the caller dials the private line number, yet another ring cadence is transmitted, causing the telephone to ring with yet another different pattern. By this method, the customer knows which telephone number has been dialled.

Obviously, such a system can be utilised in a business environment as well, whereby a number of departments or individuals are assigned a different telephone number, each with a different ring tone.

However, one of the main disadvantages ofthe above-described type of distinctive ring system is that every telephone on the line will ring, irrespective of which telephone number has been dialled. Thus, although the customer may know to whom a call is directed by the ring tone emitted by the telephones, it is still necessary to listen to the ringing of all telephones, irrespective of which number has been dialled, which is obviously inconvenient.

Another problem arises if selective use of a telephone answering device or facsimile machine is required with the telephone system. Conventional telephone answering machines and facsimile machines are usually activated by the ringing of the telephone, and many of these machines cannot discriminate between the various distinctive ring cadences which may occur on the line. Thus, such machines may answer or respond to the telephone, irrespective of which cadence is transmitted to the customer. However, it may desired to activate the answering machine or the facsimile machine in response to one respective telephone number, which is not possible using the above-described prior art system.

Thus, the present invention is primarily concerned with the conversion of the above-described type of distinctive ring telephone system to a selective ring telephone system which overcomes the above-mentioned problems.

US Patent No. 4,782, 518 describes converter apparatus for converting a distinctive ring telephone system to a selective ring telephone system. A single converter is provided at the customer's premises and is connected to the main telephone line. A plurality of sockets are provided to permit a plurality of ancillary telephone lines to be connected thereto. The converter includes a switching circuit which is operable to switch a ring signal to one or more of the ancillary telephone lines (while preventing the passage of that signal to the remaining ancillary lines), and the switching circuit is operated by a cadence-sensing logic circuit. The cadence logic circuit identifies an incoming ring cadence and causes the switching circuit to permit (or otherwise) the ring cadence to pass through to each of the ancillary telephone lines, causing the respective telephone to ring (or not), according to customer requirements.

In US Patent No. 5040209, a controller is once again provided between the main telephone line (or the PSTN) and the ancillary telephone lines required to be supported by the system. The controller is once again responsive to a number of distinctive ring cadences and includes a number of output ports, each of which is associated with a respective one of the ringinitiating signals and is arranged to have, for example, a telephone, answering machine, facsimile machine or some other type of telecommunications devices connected to it. The

controller, upon detecting a distinctive ring signal, prevents it from reaching all other connected devices and diverts it to just the device to which the ring signal is directed.

Other prior art arrangements prevent automatic response to a distinctive ring signal and require a selection action by the user. For example, US Patent No. 5086458 describes an arrangement whereby the caller dials a single telephone number for all ancillary telephone lines and is then required to press a key on their telephone touch tone keypad to select a specific extension. A remote unit then generates a ringing signal for the selected extension.

In yet another known system, such as that described in US Patent No. 4910764, an interface is provided which, when an incoming call is received, determines whether or not a tone characteristic of a facsimile transmission is present. If such a tone is determined to be present, the call is connected to a facsimile machine by a local ring action, If no such tone is detected, the call is connected to a telephone via a local ring action.

In all of the above-mentioned prior art systems, a control box for connecting the main telephone line to the ancillary telecommunications devices must be installed, to enable multiple devices connected to the single main telephone line to respond selectively to incoming calls. In general, control boxes of this type do not work with existing parallel plan telephone wiring systems usually found in homes and offices. Standard telephone sockets are generally connected in parallel around a premises, usually as a"daisy chain". The abovedescribed prior art devices rely on the fact the telephone pair coming in to the premises can be connected to the control box and all equipment which needs to be connected to it can be "star wired"back to the control box. Thus, unless all of the ancillary telecommunications devices (i. e. telephones, facsimiles, etc. ) are to be situated in the same room as the control box and plugged directly into it, which is not always convenient, the customer's existing telephone wiring system must be substantially adapted or even changed to receive the control box and any other additional apparatus, which adds both expense and complexity to the system.

We have now devised an arrangement which overcomes this problem and provides an improved telecommunications apparatus for converting a distinctive ring service to a selective ring function.

Thus, in accordance with a first aspect of the present invention, there is provided telephone apparatus for enabling two or more ancillary telecommunications devices to be connected to a single telecommunications subscriber line, the apparatus comprising a telecommunications device for connection to said subscriber line, said telecommunications device comprising at least one connection port for connecting an ancillary telecommunications device to said subscriber line, said subscriber line being accessible by means of at least two different telephone numbers, said telecommunications device being arranged to operate in one of at least two modes of operation, a first mode of operation causing the respective ancillary device to operate in response to the subscriber line being accessed by means of a first telephone number, and a second mode of operation causing the respective ancillary device to operate in response to the subscriber line being accessed by means of a second telephone number (different to the first).

The apparatus beneficially includes selection means (such as a switch or the like) for selecting the mode of operation of the telecommunications device. It will be appreciated that, in a preferred embodiment, the apparatus preferably comprises a first telecommunications device arranged to operate in the first mode of operation, and a second telecommunications device arranged to operate in the second mode.

In accordance with a second aspect of the present invention, there is provided telephone apparatus comprising a plurality of telecommunications devices, each connecting an ancillary telephone device to the same subscriber line, each of said telecommunications devices comprising privacy means for preventing access by the other telephone devices to said subscriber line when its own respective device in connected to said line.

Thus, the present invention utilises the distinctive ring service provided by many telecommunications companies around the world to permit the use of two or more telephone

numbers to access a single subscriber line. The present invention analyses the incoming ringing pattern and determines whether it should ring its associated ancillary telecommunications device based on the incoming ring pattern. In one exemplary embodiment of the present invention, switch means are provided for allowing the user to select whether the device responds (say) to a normal ringing pattern or a predetermined distinctive ring.

There are a number of circumstances in which the device of the present invention would be useful, as follows.

When a customer subscribes to a distinctive ring service, they are allocated at least one new telephone number (as well as retaining their existing telephone number).

In view of this, the customer could, for example, tell people that the new telephone number is his fax number. The customer would plug their fax machine into the device of the present invention. When the fax number is dialled, the telephone exchange generates the second distinctive ring pattern. This is detected by the device which will then ring the fax machine which will answer the fax call. When the regular number is dialled, the exchange will generate the normal ring pattern. The device will detect this and not ring the fax machine.

Virtually every business and home PC is sold with a fax capable modem which can be connected to a device of the invention for automatic, unattended answering of fax or data calls, without the risk of the PC attempting to answer voice calls.

An additional useful feature of the present invention is its"privacy"capability. If there is a call in progress, the device can"secure"the line. If an extension telephone is lifted the fax or data call will not be disturbed, and there will be no loss of data, or dropped lines.

It is possible to"give"the second phone number to a teenage daughter or son, as their private telephone number, to save the customer from answering their numerous phone calls.

If devices of the invention are plugged into the main telephone sockets around the home, these can be switched to respond to the normal ring. The device in the teenager's bedroom can be switched to respond to the distinctive ring.

Incoming calls for the teenager ring only in the teenage bedroom, incoming calls for other members of the family, dialled with the regular number, cause the other telephones to ring.

The device privacy feature keeps"teen talk"private and undisturbed.

Business people working from home can give out the distinctive ring number as their office number. By plugging the device into their telephone equipment in a way similar to that described above, they can ensure that the phone dedicated to the business is the only one which will ring when the business number is called.

This gives the opportunity to anser the telephone professionally with a suitable business associated greeting, and avoid giving the home telephone number to business contacts.

In bars, cafes, restaurants and other business establishments, a payphone will often share the subscriber line with the regular business line into the establishment. Unfortunately, this means that incoming calls for the payphone (which will usually be for the customers of the bar) cannot be distinguished from incoming calls to the bar phone (which will be for the owner or staff). Very often a second line is provided for the payphone, but this is relatively expensive.

Simply plugging the payphone and bar phone (s) into separate devices 100 connected to respective telephone extensions 102 as shown in Figure 3 will allow one number to be dialled for calls to the payphone, and a different number to be dialled for calls to the bar.

Electronic Point of Sale Equipment (credit card terminals etc) operate in various ways.

A significant number of terminals (particularly in sites like petrol stations) operate"off line". In this style of operation, credit card transactions are stored in the equipment throughout the

day. At the end of the day a central computer dials the EPOS terminal to"collect"the transaction records. The EPOS terminal automatically answers the call in response to the ringing on the line.

Because the EPOS terminal answers all incoming calls it usually sits on its own dedicated telephone line. An alternative would be to connect the EPOS terminal through device according to the invention to an existing telephone line. The polling computer service would dial the"distinctive ring"telephone number. The device would detect this distinctive incoming ringing and ring the EPOS terminal, causing it to answer automatically.

All other calls made to the line would use the regular telephone number. The device would ensure that the EPOS terminal was not"rung"for these calls, and therefore would not answer.

In the UK, sites like petrol stations are already obliged to have one telephone line (for Health and Safety reasons). The apparatus according to an exemplary embodiment of the present invention can save the cost of an additional telephone line.

The present invention provides an affordable device which can be plugged into existing telephone line sockets and telephones, wherever needed, without the need to rewire the premises. Thus, such devices can be obtained and used immediately.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure I is a perspective diagram of telecommunications apparatus according to an exemplary embodiment of the present invention; and Figure 2 is a circuit diagram of electronic circuitry which may be used in the telecommunications apparatus of Figure 1.

Referring to Figure I of the drawings, telecommunications apparatus according to an exemplary embodiment of the present invention comprises a housing 10 within which the device circuitry (not shown) is housed. The housing 10 has a connection socket 12 for receiving the connecting plug of an ancillary telecommunications device (not shown, such as a telephone extension, fax machine, or the like (not shown), and a connecting plug 14, connected to the housing 10 and the circuitry by means of a short line cord 16, for connecting the apparatus (and an ancillary telecommunications device) to a telecommunications subscriber line via a standard telephone socket or the like. A slide switch 18 is provided on the outer surface of the housing 10 to enable the user to select the mode of operation of the device.

Referring to Figure 2 of the drawings, there is shown a circuit diagram of the electronic circuitry used in this exemplary embodiment of the present invention. The device is connected to a telephone subscriber line via header J2 (which is connected via the short line cord (16) to the connecting plug (14) by means of which the device can be plugged into a standard telephone extension socket. A telephone pair A and B are connected to the header J2 at pins 2 and 4, and a derived ring wire is connected to the header J2 at pin 2.

A privacy circuit is provided by components Ql and Q2. When the device is in the idle state, there is a voltage of about 50 Volts across the line between pins 2 and 4. However, a telephone or similar telecommunications device connected between pins 2 and 5 of J 1 will fire the diac which triggers the triac. The triac then clamps to its holding current, in which case there will now be a voltage of about 10 Volts between pins 2 and 4 of the header J2 which is insufficient for the diac to conduct in other virtual line telecommunication devices according to the invention connected to other telephone extensions, such that they are prevented from connecting to the subscriber line and extension privacy is maintained.

The components around Rl, D2, Dl, C5 and C2, and Ul form a ring detect circuit. The ringing voltage between pins 3 and 4 of J2 is integrated and fed to an opto diode of an opto isolator. The envelope (cadence) of a ringing signal is detected at pin 5 of U2 (which is the

processor on the other side of the opto isolator. It is necessary to isolate the signal because the polarity of the incoming line at pins 2 and 4 may be either way around.

Diodes D3, D4, D5 and D6 form a bridge with a Darlington Pair switch across the rectified points of the bridge formed by Q3 and Q4. The switch is normally on.

Upon detection of a ringing signal on the subscriber line, the processor Ul turns off the switch and thus prevents ringing current from flowing to the associated telephone at Jl. A slide switch SW1 may be employed by a user to select the mode of operation of the device, i. e. whether the associated ancillary telecommunications device should ring in response to receipt of a predetermined distinctive ring or whether it should ring in response to a standard ring.

The processor determines (at GP2) whether the incoming ring signal is a standard ring signal or a special distinctive ring by analysing its cadence (for example, a standard UK ring may be for 0.4 seconds on, and off for 0.2 seconds, followed by 0.4 seconds on, 2 seconds off, whereas a distinctive ring may be on for I second and off for 2 seconds) and produces an output to turn on the switch formed by Q3 and Q4 at GPO or GP I if the detected ring signal corresponds to the ring signal required to operate the associated ancillary device according to the position of the slide switch SWI. Thus, the position of the slide switch SWI determines whether the associated ancillary device is ring by the normal ring or the distinctive ring (according to the telephone number dialled by the caller to access the subscriber line).

The load R4 and LED D8, and its protection diode D7, form a simple ring indicator with D8 illuminating in response to the ring voltage at pin 3 of J2. The crystal XI, C3 and C4 provide the oscillator frequency control components for the processor U2.

BT I and BT2 (1.5 V AA cells) provide power for the circuit. They ensure that no DC current is needed to be taken from the exchange line. Only limited current is available from the telephone line in the UK in the idle state of the device. This is a maximum of 120 microamps.

Although it would be possible to power a device according to the invention from this current, it would not be possible to power say three such devices (in different extensions on the same subscriber line), or two such devices with associated telephones requiring some line current

to maintain the telephone memories. Thus, battery power has been adopted in this exemplary embodiment of the invention so as to ensure that there is no limit imposed on the number of devices which may be employed on a single subscriber line. The device of the present invention has a very low power requirement, thereby enabling a single set of cells to provide many years of operation.

GP3 is used at power up to sense movement of the switch SW If SWI is moved back and forward a couple of times within the first, say, the first four seconds of powering up the device, then it is set in a'Mini Business System Mode'. In this mode of operation, the device will not pass standard ringing through if the switch is set to respond to distinctive ringing (and vice versa), unless such ringing persists for more than (say) 12 seconds, in which case it will pass the otherwise barred ringing through (assuming that the person at the required telephone extension is not available to answer their telephone), thereby providing a"Divert on No Answer"facility like an office switch board. For example, a customer may have a first device and associated telephone extension in their living room and a second device and associated telephone extension in their teenager's bedroom. The first device may be arranged to operate the associated telephone in response to standard ringing, whereas the second device may be arranged to operate the teenager's telephone in response to distinctive ringing. With the "Divert on No Answer"facility, if the teenager's telephone is not answered within (say) 12 seconds, the first device may operate the associated telephone in the living room so that the call can be answered on behalf of the teenager.

An embodiment of the invention has been described above by way of example only, and it will be apparent to persons skilled in the art that modifications and variations can be made to the described embodiment without departing from the scope of the present invention.

Claims

CLAIMS:

1. Telephone apparatus for enabling two or more ancillary telecommunications devices to be connected to a single telecommunications subscriber line, the apparatus comprising a telecommunications device for connection to said subscriber line, said telecommunications device comprising at least one connection port for connecting an ancillary telecommunications device to said subscriber line, said subscriber line being accessible by means of at least two different telephone numbers, said telecommunications device being arranged to operate in one of at least two modes of operation, a first mode of operation causing the respective ancillary device to operate in response to the subscriber line being accessed by means of a first telephone number, and a second mode of operation causing the respective ancillary device to operate in response to the subscriber line being accessed by means of a second telephone number (different to the first).

2. Apparatus according to claim 1, including selection means for selecting the mode of operation of the telecommunications device.

3. Apparatus according to claim 1 or claim 2, comprising a first telecommunications device arranged to operate in the first mode of operation, and a second telecommunications device arranged to operate in the second mode.

4. Telephone apparatus comprising a plurality of telecommunication devices, each connecting an ancillary telephone device to the same subscriber line, each of said telecommunications devices comprising privacy means for preventing access by the other telephone devices to said subscriber line when its own respective device is connected to said line.

5. Telephone apparatus substantially as herein described with reference to the accompanying drawings.