Blocking system for expensive outgoing telephone calls

A. BACKGROUND OF THE INVENTION

The invention relates to a method for deactivating a subscriber line, such as a telephone line, and a method for activating a deactivated subscriber line. The invention further relates to a communication system, such as a telephone system, in which such a method is applied.

There is a growing need for protection against telephone line abuse. Parents want to prevent their children from choosing expensive numbers (such as 06 numbers) and thereby increase the telephone bill. There is also a wish among companies that employees do not choose entertainment numbers or call abroad unnecessarily. Many solutions have already been proposed to make dialing certain numbers more difficult.

For example, Canadian patent 1,301,973 discloses a device for blocking calls to prohibited telephone numbers. This device must be placed between the telephone and the telephone connection. This makes it possible to circumvent this known device relatively simply.

It is more effective to create a list of prohibited numbers. In the Netherlands, for example, it is possible to block 06 numbers in the exchange. However, this does not prevent third parties from misusing someone's telephone connection by, for example, setting up a so-called calling house during their holiday in their home, where international calls can be made at competitive rates.

B. SUMMARY OF THE INVENTION

The object of the invention is to eliminate the above and other disadvantages of the prior art and to provide a method which makes it possible for a subscriber to block all outgoing calls in a simple manner. In addition, the invention aims to provide a method which makes it possible to (re) activate a subscriber line thus deactivated quickly and easily.

According to the invention, a method for deactivating a subscriber line comprises issuing a deactivation command and an access code to a central linked to the subscriber line, checking the access code by the exchange, and blocking outgoing calls from the subscriber line by the exchange. The deactivation command can be similar to existing network services, such as forwarding (* 21), and include, for example, the command * 98. In order to prevent accidental or unauthorized deactivation of the subscriber's line, an access code is advantageously added to the deactivation command, although it will be clear that a command without an access code is in principle sufficient. In the exchange, the access code is checked, after which the subscriber's line is blocked for outgoing calls if the result is positive. This can be done by placing the relevant subscriber number, or another number related to the subscriber line in question, in the exchange in a table, the table always being consulted when making calls.

Incoming calls can also be blocked, but this is not necessary to prevent misuse.

When a subscriber's line is deactivated, a non-standard dial tone may be issued to the subscriber's line to remind the subscriber that the subscriber's line is deactivated. Likewise, when a subscriber's line is deactivated, an alert signal can also be given to a party calling the subscriber's line.

According to the invention, a method for activating a deactivated subscriber line comprises issuing an activation command and an access code coupled to the subscriber line, checking the access code by the exchange, and releasing calls outgoing from the subscriber line by the exchange . The access codes associated with the deactivation command and the activation command can be identical.

Another object of the invention is to indicate a system in which the method is applied.

C.

REFERENCES [1] [2]

CA 1,301,973

EP 0,607,767

D.

IMPLEMENTATION EXAMPLES

The invention will be explained below with reference to the following

4

<img file="NL1002004C2_D0001.tif" />

drawing will be explained in more detail.

Figure 1 schematically shows a telephone system in which the invention is applied.

The system 1 shown in figure 1 comprises a telephone network 2 with coupled exchanges 3 and 4. A subscriber line is coupled to the exchange 4, to which a telephone 6 is connected. Furthermore, several subscriber lines, not shown in more detail, can be coupled to the exchanges 3 and 4.

If the holder of the subscriber's line 5 wishes to prevent the device 6, and furthermore all devices that can be connected to the subscriber's line, from not generating outgoing calls, he can (temporarily) deactivate the subscriber's line 5 in a simple and quick manner. To do this, he picks up the telephone receiver, dials the deactivation command (for example * 98), then enters his access code (for example 5432), possibly followed by a closing character (for example #), and hangs up. The total command then has the following form: * 98 5432 #. It will be clear that the identification of the holder can also take place in another manner, for instance by inserting an identification card, such as a smart card or chip card, into a telephone set up for this purpose.

In the exchange 4, after the identity of the holder has been checked, measures are taken to prevent outgoing calls from subscriber line 5. This can be done in a similar way as with the existing blocking of purchase numbers (06 numbers). For example, a table with subscriber lines, which may not make outgoing calls, can be present in exchange 4. In that case, deactivating a subscriber line means that the subscriber line is added to the relevant table.

It will moreover be clear that further exchanges may be connected between the displayed exchange 4 and the subscriber line 5, such as district exchanges. Thus, the actual deactivation of a subscriber's line does not have to take place in an exchange directly coupled to the subscriber's line.

The deactivation command is issued from the subscriber line 5. In most cases this will be done by means of a telephone 6 connected to subscriber line 5, but can also take place via another device (not shown) connected to subscriber line 5.

The deactivation, as indicated above, has the result that calls from the subscriber's line 5 do reach the exchange 4, but are not forwarded from there. An exception can be made for emergency services, such as 06-11. Calls that reach the exchange 4 (for example via the exchange 3) and are intended for the subscriber line 5 can be forwarded.

If the subscriber, ie the holder of the subscriber's line 5, wishes to (re) activate the line, he picks up the telephone handset, dials the activation command (for example * 99), then enters his access code (for example 5432), possibly followed by a closing sign (for example #), and hang up. The total command then has the following form: * 99 5432 #. Subscriber line 5 is then activated in exchange 4, for example by removing the respective subscriber line from the table with deactivated subscriber lines.

It will be apparent to those skilled in the art that the invention is not limited to the embodiments shown and that many modifications and additions are possible without departing from the scope of the invention.

υ 0 2 0 0 4