GB2255690A

GB2255690A - Telephone call logging apparatus and method

Info

Publication number: GB2255690A
Application number: GB9209995A
Authority: GB
Inventors: Ian Robert Casselden; Robert Caldebank
Original assignee: INTERFACE DEVICES Ltd
Current assignee: INTERFACE DEVICES Ltd
Priority date: 1991-05-08
Filing date: 1992-05-08
Publication date: 1992-11-11
Also published as: GB9209995D0; GB9109927D0

Abstract

An apparatus and method for logging calls on a telephone connected to a telephone network, comprising: determining a first point in time during the period of connection of a call at or near the commencement of the period of connection of the call, said first point in time having a predetermined relationship to the time of initial connection of the call; determining a second point in time coinciding with the end of the period of connection of the call; and calculating the time period of connection of the call from said first and second points in time. Determining the first point in time may be achieved in a variety of ways thus enabling the apparatus to be connected to different networks such as "British Telecom", "Mercury" or others. Examples of determining the first point in time are using pulse signals, or, when these are not available estimating the first point in time from the time taken to dial a call plus the average time for answering a call. <IMAGE>

Description

-IELEPHONE CALL~LOGGING APPAPAT S AND METHOD The present invention relates to telephone call logging apparatus and method. Telephone call logging apparatus is known and comprises apparatus which may carry out, for a telephone system, such as a private exchange (PABX), one or more of the following steps: a) detect each telephone call b) detect the duration of each telephone call c) provide an indication of the charge for each telephone call.

So far as telephone systems in the UK are concerned, when a call is placed via the British Telecom Telephone Network the telephone exchange starts monitoring the cost of the call from the moment of connection.

The local exchange detects a change in state at the received party handset. Each time a unit of cost is consumed, the local exchange provides a pulse which is counted by a counter which keeps a total count for billing purposes.

The subscriber may, at his option, request that the pulses (approximately 50 volts), be passed down the telephone line and thus be available for detection by the subscribers equipment. Existing call logging equipment uses these pulses to record telephone usage and provide reports on such telephone usage.

Modern equipment in continuation with the PABX systems include a meter pulse detection circuit and would provide a count of the units used together with the cost together with other information that can be provided, at an output to which may be attached to a montor. The output usually takes the form of a RS 232 port which can usually provide the following information: Date, Time, Duration of each call (i.e. hand set off hook time), Number Dialled, extension number (from which the call was made), trunk number (i.e. which exchange line was used), units of charge used (the number of meter pulses detected), status, external call indicators.

Other telephone network systems, for example the Mercury Network, oDerate in a different manner and do not provide the high voltage pulses to enable call charging and logging to be recorded in the manner discussed above with respect to the BT network. This can lead to inaccuracies when calls are to be routed via both B and another network, e.g. "Mercury" on the basis of economy. In the common arrangement either the PABX, or additional equipment, determines the route by use of the dialled digits of a call. It could also be determined by the user, e.g. by using "7" in place of the usual "9" for an outside line.

Within this specification reference to a "smart box" includes any apparatus, whether known or not, which may be connected for the purpose of route determination, which may be within the PABX itself, and which includes software, or combinations of apparatus and software.

Currently the call logging apparatus will only be enabled to provide information regarding the costs of calls via the British Telecom Network and will ignore calls via the other networks. It is an obJect of the invention to enable telephone call costing and logging for both BT and non BT networks, ny determination of connected duration for the purpose of call cost calculation.

The present invention accordingly provides a method for logging calls on a telephone connected to a telephone network, comprising: determining a first point in time during the period of connection of the call, said first point in time having a predetermined relationship to the time of initial connection of the call; determining a second point in time coinciding with the enq of the period of connection of the call; and calculating the time period of connection of the call from said first and second points in time.

In one aspect of the invention in such a method determining said first point in time comprises detecting a signal provided on the telephone network at a predetermined time interval after the connection of a call; determining said second point in time comprises measuring the call time interval from said signal to the end of the call; and calculating said time period of connection of the call includes adding said predetermined time interval to said call time interval.

In using the method of the invention with the Mercury telephone network, the signal detected comprises a short (165 Msec) tone at 1111 Hz which is specially provided and passed to the calling telephone, on all calls at a predetermined time interval of approximately two seconds after connection is detected by the network.

However, with other telephone networks, other signals may be used at different frequencies and at different timings. In some cases, it is not possible to provide such a signal, or it is not provided for other reasons.

In a further aspect, the invention provides such a method in which determining said first point in time comprises assessing the time taken to dial a call and adding to that assessed time a time interva; appropriate to an average time for the answering of a call, from the completion of dialling, to give an answer-time period; determining said second point in time comprises determining the time interval from the commencement of dialling of the call to said second point in time to give an off-hook period; and calculating said time period of connection of the call includes subtracting said answer period from said off-hook period to give the time period of connection of the call.

Such an arrangement can provide at least a good approximation to the required answer, although clearly there are limitations as to its accuracy.

The time taken to dial the call may be assessed by measuring the time taken during dialling.

Alternatively, the time taken to dial the call may be assessed by counting the number of digits dialled.

In a yet further aspect, the present invention provides apparatus for logging calls on a telephone connected to a telephone network, comprising: first means for determining a first point in time during the period of connection of a call at or near the commencement of the period of connection of the call, said first point in time having a predetermined relationship to the time of initial connection of the call; second means for determining a second point in time coinciding with the end of the period of connection of the call; and third means for calculating the time period of connection of the call from said first and second points in time.

Preferably in one arrangement said first means comprises means for detecting a signal provided on the telephone network at a predetermined time interval after the connection of a call; said second means comprises means for measuring the call time interval from said signal to the end of the call; and said third means is arranged to add said predetermined time interval to said call time interval to give the time period of connection of the call.

Preferably, in a further arrangement, said first means comprises means for assessing the time taken to dial a call and adding to that assessed time a time interval appropriate to an average time for the answering of a call, from the completion of dialling, to give an answer-time period; said second means is arranged to determine the time interval from the commencement of dialling of the call to said second point in time to give an off-hook period; and said third means is arranged to subtract said answer period from said off-hook period to give the time period of connection of the call.

In order to provide a fuller understanding of the above and other aspects of the invention, an embodiment will now be described, by way of example only, with reference to the accompanying drawing, which 5 a diagrammatic diagram of a telephone network, a PABX exchange, and call logging apparatus attached thereto.

Referring to the figure, the illustrated telephone system comprises a set of telephones (10A, 10B ...), each connected in a conventional way to a local exchange PABX exchange 11. The PABX exchange 11 is connected to, in this case, two telephone networks (13,14) via a telephone line 20 and a "smart box" (12) which routes outgoing calls to whichever of the networks (13,14) is cheaper for that particular call.

There may, of course, be further networks. Such an arrangement is conventional.

In alternative arrangements, the PABX may embody the "smart box" or provide its function integrally. As an output from the PABX (11), is a signal line (16) which is connected directly to the outgoing telephone line, the signal line (16) being connected to a signal detector (17). The signal detector is connected to a computer (18), which may form part of either the PABX or the "smart box". The function of the computer, which will be described below, provides an output signal as indicated at (19).

Although the "smart box" (12) is shown schematically in the drawing as having separate access to each of the networks (13,14); in practice, there is a single access line to an exchange where access to the different networks is achieved by the "smart box" transmitting different digits to the exchange.

In the embodiment shown, the signal detector (17), which also may form part of the PABX (11), includes the following items (not shown in the drawings).

1. Means for detecting British Telecom Network pulses on the line 20 from one of the networks, when that network is British Telecom; and passing a suitable first signal to the computer (18), on the receipt of each such pulse.

2. Means for detecting pulses on the line 20 from a second telephone network, such as a pulse from the Mercury Network comprising a 165Msec signal of 1111 Hz. (hereafter called the "Mercury Pulse"), when that second network is the Mercury network; and passing a suitable second signal to the computer (18).

In the embodiment shown, the computer (18) includes as hardware or 1. Means for passing information from the PABX (11) to the computer (18) including "off-hook" time, number dialled and the telephone extension from which the number was dialled.

2. Means for discriminating between a connection to British Telecom Network and other networks, such as Mercury Network, from the number dialled or otherwise.

3. Means for receiving such first signals from the signal detector (17) and thereby counting British Telecom pulses received on the line 20.

4. Call logging apparatus of generally conventional type per se arranged to operate in response to such received British Telecom pulses.

5. Means for receiving such second signals from the signal detector (17) indicative of pulses received from the Mercury Network.

6. Means for measuring the period of time elapsing from the receipt of a Mercury Pulse to the end of a call made.

7. Means for adding to that measured period of time a predetermined period of time (which is actually the known period of time between the connection of the telephone call and the arrival of the Mercury Pulse).

8. Means including an algorithm to calculate from the determined period of the telephone call, and from a number called, a measure of the charge for that telephone call.

9. Means for providing the PABX with control information for implementing such functions as selective call ? on the basis of the number dialled.

The signal detector (17) may also be embodied in the computer 18.

In use of the apparatus, when a telephone (10A, 10B ) is connected via the PABX (11) to an external telephone line, the "smart box"(12) calculates from the digits dialled, whichever is the cheaper network (13) or (14) to use for that call, and routes the call through the cheaper network. If the "smart box" (12) connects the call to the British Telecom Network, then after the call is connected, the normal British Telecom pulses are passed from the line 20 down the signal line (16), to the signal detector (17) which passes said first signals to the computer (18). The pulse counter and call logging apparatus per se operates in a generally conventional manner to provide a suitable output indicative of the cost of the call, on signal output (19), either immediately after the call, or at a later time after storage in a memory.

If, however, the "smart box" (12) connects the telephone to the Mercury Network, then the apparatus works in the following manner.

Operation of the apparatus is based on the fact that the Mercury telephone network has been extended to include the emission of a single short (165Msec) tone (1111 Hz), ie the Mercury pulse, which is routed on line 20, to the PABX, approximately 2 seconds after connection is detected by the Mercury Network. This Mercury pulse is a product of the Mercury Network's own billing mechanism and has been connected onto the line and may be considered as a "connected indicator".

Thus, when the smart box" (12) connects the telephone line to the Mercury Network, some 2 seconds after the telephone has been connected to the remote party, the Mercury pulse is passed down the signal line (16) to the signal detector (17). The signal detector (17) then passes the above mentioned second signal to the computer (18), indicating the detection of a Mercury pulse. The means within the computer (18) for measuring the period of time from the Mercury pulse to the end of the call is then set in operation and when the call is terminated, provides this period of elapsed time for the call. The 2 second period from the commencement of the call to the receipt of the Mercury pulse, is then added by the computer (18) to that measured period to provide a measure of the total period of time for the call. This period of time can then be passed to the means for calculating the charge, as an input to the algorithm, the calculating means having already received the telephone number of the called party is thus enabled to calculate the charge for the particular telephone call. This may be stored or may be passed direct to the signal output (19).

In this way, the apparatus described can provide at the signal output (19), a signal which provides telephone call logging information for telephone calls provided both by the British Telecom Network and by the Mercury Network.

The invention is not restricted to the details of the foregoing example.

The signal detector (17) for instance, may include: a means for detecting the "Mercury pulse" or other such signals from other networks, a means for detecting dialled digits, both tone and loop disconnect, a means for detecting BT style pulses a means for timing events a means for communication with other equipment a means for signal processing an optical interface an inductive interface to the exchange lines a means for injection tones to the network lines.

Any of the components 11, 12, 17 may be used to detect tones on the line and may be connected directly to the computer 18.11. We have referred to the Mercury Network as an alternative to British Telecom, but there are other networks, and providing a suitable pulse or signal is provided indicating connection of the call, then a similar arrangement may be utilised.

The signal line (16) may be connected to the installed telephone system in a number of ways.

The signal line (16) may be directly connected to the relevant telephone network lines either in series or in parallel, and the tone detected using suitable detection electronics.

Alternatively, the signal line (16) may be connected inductively to the exchange lines, for example, using ferrite beads and suitable detection circuits, including electronic filters and amplifiers. This saves interference with the telephone lines.

The signal line (16) may be connected optically to the "smart box" (12). Many varieties of "smart box" (12) include a light emitting device which is illuminated whilst the telephone call is in operation.

The signal line (16) may be directly connected to tone detectors within a PABX.

The signal line (16) may be directly connected to the "smart box" (12) by hard wired electronic circuits that form part of the "smart box" via a suitable interface such as an RS 232 interface. The interconnection between the smart switch and the signal detector (17) may range from a simple logical level change on a line per exchange line or full error corrected communications supplying details such as date, time, telephone number dialled, true duration, time or connected tone.

The computer (18) may be a general standard type of stand alone computer running suitable software. The signal output (19) may be connected to an output device such as a printer or to an accounting computer. Details of telephone calls may be accumulated by telephone extension or otherwise, and reports may be prepared indicating the savings and usage of the different telephone networks.

A run time log printout may be produced or individual reports. The system may support connection to a modem and thus enable external connection to the data enabling the data to be accessed remotely or periodically transmitted to another computer.

In the case where the telephone is connected to a network which does not provide either British Telecom type pulses, or Mercury type pulses, then the computer (18) may provide a nominal value for the chargeable period of a telephone call by measuring the "off-hook" period of time for the telephone call, and subtracting therefrom a first period of time required to complete the dialling process, which may be a measured period or may be estimated from the number of digits dialled, and a seconde period of time allowing for a typical answer time, which may be estimated from predetermined data.

The apparatus of the invention has a number of applications.

1. The apparatus is particularly applicable for use in hotels to produce call-logging information and billing information for each telephone extension in each room.

2. Time monitoring for solicitors and accountancy practices where there is a charge for a time. In this use, a dedicated number may be dialled to indicate both the member of staff and the client account, and this number would not be routed through the telephone network. The computer (18) may detect the relevant digits and may store and output to the signal output (19) an indication of the time utilised on a particular job for a particular client.

3. Access control to the public network. Access to an outside network might be controlled by requiring the use of a unique code (with check sum) for each individual who is entitled to use the outside telephone lines. This code could be entered in place of the usual "9" to gain access to the network. Each call could be monitored and allocated to an individual.

4. Private networking costing over any carrier. This includes the terminal equipment within both the PABX and local exchanges that use "connected" tones to indicate call answer.

5. Traffic analysis over networks that do not provide pulse indicating charge.

Claims

1. A method for logging calls on a telephone connected to a telephone network, comprising: determining a first point in time during the period of connection of a call at or near the commencement of the period of connection of the call, said first point in time having a pre-determined relationship to the time of initial connection of the call; determining a second point in time coinciding with the end of the period of connection of the call; and calculating the time period of connection of the call from said first and second points in time.

2. A method as claimed in Claim 1, in which determining said first point in time comprises detecting a signal provided on the telephone network at a predetermined time interval after the connection of a call; determining said second point in time comprises measuring the call time interval from said signal to the end of the call; and calculating said time period of connection of the call includes adding said predetermined time interval to said call time interval.

3. A method as claimed in Claim 1, in which determining said first point in time comprises assessing the time taken to dial a call and adding to that assessed time a time interval aPpropriate to an average time for the answering of a call, from the completion of dialling, to give an answer-time period; determining said second point in time comprises determining the time interval from the commencement of dialling of the call to said second point in time to give an off-hook period; and calculating said time period of connection of the call includes subtracting said answer time period from said off-hook period to give the time period of connection of the call.

4. A method as claimed in Claim 3, in which the time taken to dial the call is assessed by measuring the time taken during dialling.

5. A method as claimed in Claim 3, in which the time taken to dial the call is assessed by counting the number of digits dialled.

6. Apparatus for logging calls on a telephone connected to a telephone network, comprising: first means for determining a first point in time during the period of connection of a call at or near the initial commencement of the period of connection of the call, said first point in time having a predetermined relationship to the time of commencement of the call; second means for determining a second point in time coinciding with the end of the period of connection of the call; and third means for calculating the time period of connection of the call from said first and second points in time.

7. Apparatus as claimed in Claim 6 in which said first means comprises means for detecting a signal provided on the telephone network at a predetermined time interval after the connection of a call; said second means comprises means for measuring the call time interval from said signal to the end of the call; and said third means is arranged to add said predetermined time interval to said call time interval to give the time period of connection of the call.

8. Apparatus as claimed in Claim 6, in which said first means comprises means for assessing the time taken to dial a call and adding to that assessed time a time interval appropriate to an average time for the answering of a call, from the completion of dialling, to give an answer-time period; said second means is arranged to determine the time interval from the commencement of dialling of the call to said second point in time to give an off-hook period; and said third means is arranged to subtract said answer period from said off-hook period to give the time period of connection of the call.

9. Apparatus as claimed in ClaimS, in which said time taken to dial the call is assessed by measuring the time taken during dialling.

10. Apparatus as claimed in ClaimS, in which said time taken to dial the call is assessed by counting the number of digits dialled.

11. Apparatus as claimed in any one of Claims 6 to 10, in combination with a "smart box" as herein before defined.

12. Apparatus as claimed in any one of Claims 6 to 10, including: fourth means for detecting, during connection of the call, and counting regularly spaced pulse time signals provided on the telephone network; and said third means is optionally responsive to said first and second means or said fourth means to calculate the length of the period of connection of the call.

13. Apparatus as claimed in any one of Claims 6 to 10, in which said third means includes a computer.

14. Apparatus as claimed in Claim 13, in which said computer provides said first, second or fourth means.

15. A method for logging calls on a telephone connected to a telephone network substantially as herein described with reference to the accompanying drawing.

16. Apparatus for logging calls on a telephone connected to a telephone network substantially as herein described with reference to the accompanying drawing.