AU708663B2 - A telephone arrangement - Google Patents

Description

This invention relates to the provision of a single line telephone having many of the capabilities of a two-line telephone.

Two-line telephones have been available for many years and in many forms.

Their function is to be able to access and control call information on either of two lines. Both lines terminate in the same telephone. Switching is provided between the lines to put one line on hold and then either dial out or receive a call on the other line. Also a call transfer facility may be provided when two phones worked together where a user on one telephone could signal another phone to advise that the incoming call just answered was intended for the other party. All of this was achieved without intelligence in the network, using only mechanical switching in the 2-line telephone.

With the advent of key systems, these features were readily implementable.

S. The drawback was the high cost of centralised switching equipment and its intelligence, especially for low line capacities. The cost per extension telephone was high.

With the provision of SPC exchanges in the network came a service generally referred to as "Centrex" This puts the switching intelligence in the exchange and allowed access to higher level call-control procedures and services by coded signals from POT's (plain old telephones). The coded signals were strings of dtmf digits sent to the exchange.

In recent times the exchange technology has progressed so that now the phone number and/or name of the calling party (A-party) can be provided visually to the called party (B-party) before the B-party answers the phone.

Many small telephone systems abound, but still there is the need for a two-line telephone. Today many features can be implemented cheaply by utilising the Centrex facilities in the exchange and a relatively simple single line telephone with caller-ID display. The switching of the original product, (line hold, transfer etc.) is now located in the Centrex facilities in the exchange. One remaining problem is to make the user access to these features user-friendly without the need to remember codes. This can be done by pre-programmed/labelled keys where e.g. the single action of the button sends out the string of dtmf digits to access the Centrex facilities.

Disclosure of the invention This specification proposes an arrangement which takes advantage of Centrex features to provide 2 line functionality to single line phones.

Accordingly there is provided a communication arrangement in which a single line phone is provided with two-line phone functions, the arrangement including a first telephone subset including first processor means and first memory means storing a first set of instructions, wherein the subset includes one or more dedicated function keys and wherein in response to the operation of a function key the processor causes a corresponding code sequence to be transmitted in accordance with the first set of instructions to a telephone exchange having second processor means and second memory means storing a second set of instructions, the exchange including decoder means to convert the code sequence into input instructions for the second processor means and to activate one or more functions, said arrangement further including one or more additional telephone subsets associated with the first telephone subset each having processor means and memory means and dedicated function keys, and wherein the exchange includes interconnection means to enable interconnection of the communication paths of the associated subsets.

The advantages of using Centrex is that a low cost single line telephone can be used to access the centrex features and provide 2 -line functionality. This saves wiring.

(The overall cost-efficiency however is very much dependent of the tariff structure determined by the telecom operator for the Centrex service).

Brief Description of the Drawings Figure 1 shows a switching network having Centrex features to which a pair of subsets are connected; Figure 2 is a block diagram illustrating relevant exchange functions.

Best Mode of Carrying out the Invention The invention will be described with reference to Figures 1 and 2.

Figure 1 shows a telephone network 20 including Centrex exchange facilities 21 to which a pair of single-line telephones 24 and 25 at subscriber's premises 26 are connected by lines 22 and 23 respectively. Other subscribers such as 27 are connected to network The Centrex features are shown in Figure 2. The lines 22 and 23 connect to respective line interface circuits 31 and 32 and associated dual-tone-multi-frequency DTMF) receivers 33 and 34.

The line interface circuits 31 and 32 perform upstream analog-to-digital and downstream digital-to-analog concessions, and provide the 50V line supply and ring signalling and other functions.

The DTMF receivers 33 and 34 decode the dialling signals sent from the telephone subsets and convert them to appropriate inputs for a processor (not shown).

The processor controls a cross-connect switch 30 which is used to transfer the voice signals.

An implementation will now be described with reference to the drawings in which there is shown: a) a pair of single line telephones 24, 25 having specially labelled buttons programmed in a manner consistent with the Centrex service used, b) a domestic or small business setting 26 with the same telephone type at both sites. oo*o I. c) an exchange based Centrex package where at least some of the features in the Table 1 are available.

The implementation of the two-line features are described below.

Transfer *A calls B but the call is for C After answering the all, B presses the "Enquiry" key on the phone which sends out a recall signal such as on line 22 which is detected by the line interface circuit 31 at the Centrex exchange.

This alerts the exchange processor which causes interface circuit 31 to send dial tone on line 22 as a timed loop break).

When new dial tone is given, B dials C (this can be a short number) and DTMF receiver 33 notifies the processor which is programmed to send ring signal via Line Interface Circuit 32 to subscriber C in response thereto. When C answers, B presses "Transfer" key which dials out a code, e.g. recall 4, and the exchange connects A to C and removes B.

Music-on-hold.

This comes from the network whenever the "hold" key (which dials recall) is pressed. Dialling "hold" again terminates the hold.

Call Pickup.

This may be done in two ways.

1. The exchange can send distinctive ring to both B C to indicate the telephone for which the call from A is intended. If C does not answer, and B can hear the phone ring (if his phone is not in use), B can press the pick-up button, which e.g. dials *81 and the exchange will switch B to A. If B is on the phone and can hear C's phone ring, he can place the current call on hold and press pick-up.

2. C can forward all calls on no-answer to B using the exchange. Then B can answer C's calls. If caller ID is available this may also help B see for whom the call is intended. If B is on a call and a call comes in for C, then the exchange processor may be programmed to send call waiting tones to alert him of the other call intended for C.

1*3 Intercom.

This facility can be provided via the normal Centrex facilities user-to-user (PNP) signalling, dialled call waiting etc. If caller-ID is available this will help to identify B to C (and vice versa). Distinctive ring could also help here.

Distinctive ring.

*2 Already mentioned.

Phone Mail.

A button and/or menu is provided on the phone to give access to network based phone mail.

Caller Display.

Self evident.

Call Waiting/Forwarding.

Can be provided by dedicated buttons dialling out the appropriate signals associated with the particular service.

The claims defining the invention are as follows: 1. A communication arrangement in which a single line phone is provided with two-line phone functions, the arrangement including a first telephone subset including first processor means and first memory means storing a first set of instructions, wherein the subset includes one or more dedicated function keys and wherein in response to the operation of a function key the processor causes a corresponding code sequence to be transmitted in accordance with the first set of instructions to a telephone exchange having second processor means and second memory means storing a second set of instructions, the exchange including decoder means to convert the code sequence into input instructions for the second processor means and to activate one or more functions, said arrangement further including one or more additional telephone subsets associated with the first telephone subset each having processor means and memory means and dedicated function keys, and wherein the exchange includes interconnection means to enable interconnection of the communication paths of the associated subsets.

O 2. An arrangement as claimed in claim 1,wherein in response to the transmission of a transfer signal from a first associated subset from which a first subscriber wishes to transfer a call to a second subscriber at a second associated subset, the exchange processor removes the call from the line of the first associated subset and applies dial tone to that line, and, in response to a dialled number subsequently received from the first associated subset, indicating the address of the second associated subset, the exchange applies ring single to the line of the second associated subset and transfers the call to the second associated subset when it goes off-hook.

3. A communication arrangement substantially as herein described with reference to Figures 1 2 of the accompanying drawings.

4. A telephone subset for use in an arrangement as claimed in any one of claims 1 to 3.

DATED THIS FOURTH DAY OF JUNE 7999 ALCATEL AUSTRALIA LIMITED 000 005 363)