GB2222350A

GB2222350A - Selectively using alternative telephone networks with phonecard

Info

Publication number: GB2222350A
Application number: GB8919123A
Authority: GB
Inventors: Stephen Thomas Currah
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-08-23
Filing date: 1989-08-23
Publication date: 1990-02-28
Also published as: GB8819929D0; GB8919123D0

Abstract

An automatic telephone dialling system routes dialled number selectively through a first telephone network or a second telephone network, for example according to whether the first network can handle the call or if it cannot handle the call with cost saving. This can be for BT or Mercury networks and comprises a unit, between telephone and wall socket, with a microcomputer which receives a Mercury card with a PIN on it. In the absence of the right card, all calls go via BT. With the right card, appropriate calls are automatically directed via Mercury. <IMAGE>

Description

TELEPHONE DIALLING SYSTEM This invention relates to an automatic telephone dialling system.

In the United Kingdom there is now an alternative telephone network, the Mercury Communication network, to the British Telecom network. Subscribers to British Telecom network may choose whether to use the British Telecom network or the Mercury Communications network. If a subscriber wishes to use British Telecom, he dials the relevant area code (STD) number (if required) and then the desired phone number in the usual way. If the subscriber wishes to use the Mercury Communications network, he must dial a code to access the local Mercury node, followed by his own personal identity number (PIN - ten digits), before the area code and desire telephone number. The Mercury access code connects the subscriber into the Mercury Communications network and the users' PIN is used by the Mercury system to apply the charge for the call to an account which Mercury keep for that particular user.The Mercury Communications network enables cost saving to be made on a proportion, but not all calls. Hitherto it has been necessary for the user to determine which service, the Mercury Communications or the British Telecom, it is better for him to use.

I have now devised a telephone system which automatically determines whether to use the Mercury Communications network or the British Telecom network, and dials automatically into the appropriate service.

In accordance with this invention, there is provided an automatic telephone dialling system arranged to route dialled numbers selectively through a first telephone network or a second telephone network.

This system preferably has a memory on which is stored, the users' PIN relevant to the first telephone network, an access code for obtaining access to the first telephone network and a list of all area codes for which it is desirable to be routed via the first rather than the second telephone network.

The system preferably also has means responsive to the user dialling the required number (preceded by an area code if necessary), in order to compare this number with the excluded numbers and in the absence of an identity with any excluded number, automatically dialling the access number, followed by the PIN, followed by the dialled number in order to make the call over the first network, and in the event of an identity with an excluded number, automatically dialling the dialled number to make the call over the second network.

The excluded numbers include area codes and local numbers (eg. "999") which the first network (the Mercury Communications) cannot handle or cannot handle with cost saving.

A preferred embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which: FIGURE 1 is a block diagram of a system in accordance with the invention; and FIGURE 2 is a software flow diagram to show the functioning of the system.

In the preferred embodiment, the automatic dialling system comprises an electronic unit external to the telephone handset. The unit is situated between the telephone and the telephone wall socket and arranged to receive a users' card to enable it for the Mercury Communications network, the card carrying the memory referred to above. In use, the unit seizes the line when.the reeiver is lifted. The user dials the required phone number (preceded by an area code if necessary) in the usual way. Preferably the handset uses DTMF (dual tone multiple frequency) for speed but preferably the unit is also able to accept LD (loop dialling). The unit receives the dialled digits, but does not send them to the line until the first few digits have been screened.

The unit checks that the memory card has been inserted. If not, ie. the card is absent or its electrical contacts on its edge have not matched with electrical contacts of the unit, then the unit routes the dialled number directly to the line in order to make the call over the British Telecom network. But if the card is plugged in, the unit screens or compares the dialled digits with the excluded numbers held in the card memory. These excluded numbers comprise area codes, and local numbers which Mercury Communications can not handle, at least without cost saving. If the number which the user has dialled finds a match or identity with any of the excluded numbers held in the card memory, the dialled number is routed directly to the line so that the call is made over the British Telecom network in the usual way.However if the dialled number does not find a match or identity with any of the stored excluded numbers, then the unit routes the call to the local node of the Mercury Communications network, by dialling the Mercury access code (usually 131).

The unit is arranged to wait for and recognize the access tone produced by the Mercury Communications system, then sends the PIN from the memory card (plus account code if this option is selected). the unit then sends the dialled telephone number using DTMF dialling. It will be appreciated that the memory card is personalized to the particuiar card holder. The card may be used on different telephones but will always be applied by Mercury Communications to the accocunt of th card holder. As different areas may require different procedures for obtaining access to the local Mercury Communications node, and different areas may require different sets of excluded numbers, each card may be specifically applicable for a predetermined area. As the Mercury Communications network grows, then each user may be supplied with an updated card periodically.

Referring now to the accompanying drawings, the Figure 1 block diagram shows the users' telephone at one end and the exchange line at the other with the preferred embodiment (Smart Socket) situated between. When the users' phone is take "off hook" current sensing causes the microprocessor to wake up.

The microprocesor then disconnects the line from the telephone but maintains line current to hold the line. The telephone is separately powered from a low voltage source. As dialled digits are received (LD or DTMF) the microprocessor interrogates the Memory card, constantly monitors the users telephone via the signal detection circuits, and sends/receives signalling to/from the line through the line monitor circuits.

The software flow diagram of Figure 2 shows the functioning of the unit.

Start up is always from a "sleep" or "fully off" mode. Microprocessor "wake up" is initiated by the lifting of the handset (off hook) or by the detection of a ring current.

If the source of the "wake-up" was an incoming ring then the unit enters a low power sleep mode, until the end of the call, when it switches fully off.

If the microprocessor is woken by the users' phone being taken "off hook" then the unit readies itself te receive digits from the user and to place these into a buffer; at the same time deciding whether the signalling is pulse or tone dialling. When enough digits have been stored the microprocessor screens them for local or STD calls, and checks the memory -card for Mercury exceptions and routes the call accordingly.

If the call is routed direct then the digits are echoed onto the line. If the call is routed via Mercury then the access code is read from the memory card and relayed to the line, then the unit waits for the Mercury access tone and when this arrives it sends the users PIN from the card and then the dialled number from its internal buffer. When all digits have been dialled the unit connects the phone direct to the line until the user clears down which is when the microprocessor returns to sleep mode.

Claims

1) An automatic telephone dialling system arranged to route dialled numbers selectively through a first telephone network or a second telephone network.

2) A system as claimed in claim 1, having a memory storing a users' personal identity number (PIN) relevant to the first telephone network, an access code for obtaining access to the first telephone network, and a plurality of excluded numbers for which the second network should be used rather than the first network, cr a plurality of permitted numbers for which the first network should be used rather than the second.

3) A system as claimed in claim 2, comprising means responsive to a user dialling the required number (preceded by an area code if necessary) in order to compare this number with the excluded or permitted numbers, and in the absence of any identity with any excluded number, or in the case of an identity with any permitted number, automatically dialling the access number followed by the PI > ; number followed by the dialled number in order to make the call over the first network.

4) A system as claimed in claim 3, in which in the event of an identity with an excluded number, or absence of an identity with a permitted number, the system automatically dials the number to make the call over the second network.