GB2287607A

GB2287607A - Circuitry for use in a telephone system

Info

Publication number: GB2287607A
Application number: GB9404554A
Authority: GB
Inventors: Robert Suggett
Original assignee: TELEPHONE MANAGEMENT SYSTEMS L
Current assignee: TELEPHONE MANAGEMENT SYSTEMS L
Priority date: 1994-03-09
Filing date: 1994-03-09
Publication date: 1995-09-20
Also published as: GB9404554D0

Abstract

Circuitry for use in a telephone system, comprises means (8, 9, 10, 11, 12, 13) adapted to process data indicative of the duration of and the destination of a call to generate meter pulses characteristic of the call, for use in deriving a cost of the call, and to confirm that a called party has answered. <IMAGE>

Description

CIRCUITRY FOR USE IN A TELEPHONE SYSTEM The present invention relates to circuitry for use in a telephone system.

It is known in telephone systems to generate so-called meter pulses in response to answering a call, for the purpose of costing such a call. Typically, each such pulse is a 50Hz signal burst, the time between pulses for a particular call being inversely proportional to the cost of the call having regard to the number being called and the time of day, the cost of the call being computed by counting meter pulses for the duration of the call.

Meter pulses are used, not only by telephone authorities themselves for charging subscribers, but also in socalled "call-logging systems", for example in hotels and offices. A typical arrangement in a hotel, for example, is shown in Figure 1. Reference numeral 1 designates a private automatic branch exchange (PABX) and reference numeral 2 designates a costing system for deriving the costs of individual calls from different extensions of the particular installation. Between the PABX 1 and the system 2 is circuitry 3, which derives from the PBAX 1 the meter pulses for each call made and data indicative of the dialled digits of the call, the extension from which the call was made, the time and date of the call and the duration of the call. Circuitry 3 passes to system 2 the meter pulses and the data and system 2 uses the meter pulses to compute the cost of each call for billing purposes.

If a particular telephone authority decides to cease sending meter pulses, then any such costing system 2 only using meter pulses will no longer be usable. Although costing systems are known which derive the cost of a call using an algorithm if the provision of meter pulses fails, using the time and date of the call, its duration and the destination of the call on the basis of the dialled digits, there are, nevertheless, many systems in existence which do not have this facility and only operate with meter pulses.

Also, since a meter pulse is evidence that a called party answers, a telephone authority which decides no longer to send meter pulses for costing purposes might still send just one for each call. However, any costing system using such an algorithm for costing purposes only in the event of failure of meter pulses will then only ever produce a cost according to one pulse, regardless of what the cost should actually be.

Thus there exists a need for means which enables a costing system using meter pulses as the only basis for costing calls (or one which uses an algorithm for costing in the absence of meter pulses) to operate satisfactorily in the event that meter pulses are no longer sent by a telephone authority (or just one is sent per call as evidence that the call is answered).

According to the present invention, there is provided circuitry for use in a telephone system, comprising means adapted to process data indicative of the duration of and the destination of a call to generate meter pulses characteristic of the call, for use in deriving a cost of the call, and to confirm that a called party has answered.

Preferably, the circuitry is separate from a telephone exchange. In this case, the circuitry may have an input for connection to a PABX and an output for connection to a costing system or a printer, the generated meter pulses being provided to said output.

Preferably, the circuitry comprises processor means and memory means holding data for controlling the processor means to generate said meter pulses using said data indicative of the duration of and the destination of a call.

The present invention will now be described, by way of example, with reference to Figure 2 of the accompanying drawing which is a block schematic diagram of one example of circuitry accorded to the present invention.

Referring to Figure 2, the circuitry comprises processor circuitry 4, a power supply unit 5, a display 6 and a key pad 7. The processor circuitry 4 comprises a central processing unit 8, a timer 9, input/output circuitry 10 and three electrically programable read only memories (EPROMs) 11, 12 and 13. The input/output circuitry 10 has an input 14 for connection to a PABX and an output 15 for connection to a costing system, so that the circuitry shown in Figure 2 can replace circuitry 3 in an installation as shown in Figure 1 for example.

Alternatively, the output 15 may be connected to a printer for printing data for use in costing calls from a print-out of the printer. EPROM 11 provides interfaces for the PABX and the costing system; EPROM 12 holds a program for controlling the central processing unit 8; and EPROM 13 holds an algorithm for use in generating meter pulses on the basis of tariff data tables. The circuitry could have provision to connect to a 12 volt battery for use in the event of failure of the mains supply to the power supply unit 5.

Using data from the PABX indicative of the dialled digits of each call made, the extension from which the call was made, the time and date of the call and the duration of the call, the central processing unit 8, on the basis of the program held in EPROM 12 and the algorithm in EPROM 13, generates meter pulses, the number of which and the time between successive ones of which are characteristic of the cost of the call. That is, in the absence of such meter pulses in data from the PABX, those meter pulses are generated which would have been included in the data from the PABX if the telephone authority had provided them. The generated meter pulses, together with the data from the PABX, into which data the meter pulses are inserted, are sent from the circuitry 4 to the costing system via output 15.Also, the circuitry 4 is adapted to use the data from the PABX to produce an indication confirming that the called party has answered.

The display 6 displays, for example, 8 characters on each of two lines and normally displays the current date and time. Not all PABXs provide this information and so it cannot necessarily be learnt from the PABX data. To overcome this, the key pad 7 enables this and other data items to be inputted. The display may also be capable of displaying a number of alternatives to the current date and time. For instance, the display could display a running total of costed duration and meter pulses. The key pad 7 could be used to enter a command to clear this data. Another alternative would be to display this information on a call by call basis rather than a total.

In the light of the above, it will be appreciated that the circuitry shown in Figure 2 may be used to provide meter pulses for costing purposes to a costing system which only operates using meter pulses (or one which costs on the basis of an algorithm if meter pulses fail) if a telephone authority ceases sending meter pulses (or only sends one for the purposes of detecting that a call has been answered).

Claims

1. Circuitry for use in a telephone system, comprising means adapted to process data indicative of the duration of and the destination of a call to generate meter pulses characteristic of the call, for use in deriving a cost of the call, and to confirm that a called party has answered.

2. Circuitry according to claim 1, separate from a telephone exchange.

3. Circuitry according to claim 2 which has an input for connection to a PABX and an output for connection to a costing system or a printer, the generated meter pulses being provided to said output.

4. Circuitry according to any preceding claim, comprising processor means and memory means holding data for controlling the processor means to generate said meter pulses using said data indicative of the duration of and the destination of a call.

5. Circuitry for use in a telephone system, substantially as herein described with Figure 2 of the accompanying drawing.