METHOD OF RESTRICTING THE
DURATION OF TELEPHONE CALLS AND
TELEPHONE IMPLEMENTING SUCH A
METHOD
BACKGROUND OF THE INVENTION
The present invention relates to a telephone comprising control means for controlling the cost of telephone calls, and a method of controlling the cost of telephone calls.
The invention has highly significant applications because it permits a subscriber to a telephone network to control the cost of calls made with his telephone. The invention is particularly advantageous when it is applied to mobile telephones which, by nature, admit of being handed down to ^ various persons.
British patent application No. 2 227 905, filed in the United Kingdom on 21.01.1989 describes a device intended to be connected in series with a telephone by the telephone line. This device makes it possible to set a maximum total 20 amount that must not be exceeded for all the calls. It displays the current amount and when the preset maximum amount has been reached, the telephone will be cut off for outward calls. The value of the current amount may be reinitialized by means of a key. 25
The described mechanism has various drawbacks. First of all, it needs the use of a complementary device and is only applicable to conventional corded or cordless telephones. Moreover, it provides a rough control of the telephone cost and the restriction is imposed on the basis of the amount of 30 the calls, which is relatively complex to manage given the variety of rates depending on the operators, hour ranges, . .
It is an object of the invention to propose a telephone which integrates cost control means which can be adapted to the need of the user, are simpler to implement and easier to use by the telephone user. 40
Therefore, a telephone according to the invention and as described in the opening paragraph is characterized in that it comprises:
means permitting of laying down at least one duration restriction criterion which is independently applicable 45 to each call,
means for assigning a maximum authorized duration to
each call that forms the object of such a restriction, means for permitting of interrupting a call when the
maximum duration assigned thereto has elapsed. Similarly, a method according to the invention of controlling the cost of the calls is characterized in that it comprises:
laying down at least one duration restriction criterion 55
which is independently applicable to each call, assigning a maximum authorized duration to each call that
forms the object of such a restriction, and permitting of interrupting a call when the maximum
duration assigned thereto has elapsed. 60 According to the invention, the control of cost is thus made by laying down call duration restrictions, which is much simpler to manage. These restrictions admit of being applied on a call-by-call basis, which allows of obtaining a more efficient control. 65
In a particularly advantageous embodiment, a telephone according to the invention comprises means for laying down
one duration restriction criterion for each category, the fact that a call belongs to one category being determined by the called party's telephone number.
The invention thus permits of restricting only certain categories of calls, or restricting the various categories differently, for example, local calls, international calls, . . .
In another advantageous embodiment of the invention, the telephone has a telephone directory containing records and it comprises means for laying down at least one duration restriction criterion for one or various records of said directory.
Advantageously, the telephone according to the invention comprises:
at least one counter, called call counter,
means for initializing said call counter for each call that
forms the object of a duration restriction, with the
maximum authorized duration, means for decrementing said call counter for as long as
the call lasts,
display means for displaying the value of said call counter.
The user of the telephone thus at any time knows the duration that is left before the call is cut off, which largely improves the ease of use of the telephone.
Finally, in another advantageous embodiment, the telephone according to the invention comprises
means for setting at least one time period,
means for summing the durations of the calls per category in said period,
means for setting a maximum authorized duration for said period,
means for permitting of interrupting a call that belongs to said category when the maximum duration assigned to this category has elapsed for said period, means permitting of cutting off the calls that belong to said category when the maximum duration assigned to this category has elapsed for said period. The summing of the duration of the calls per category and per period provides a very large flexibility of the use of the telephone. It is particularly interesting notably in a professional environment.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:
FIG. 1 represents an example of a telephone according to the invention,
FIGS. 2 and 3 represent the contents of a table in which are stored the various parameters relating to the restrictions that have been laid down, and
FIG. 4 represents an embodiment of a method according to the invention in the form of a flow chart.
DETAILED DESCRIPTION OF THE
PREFERRED EMBODIMENT
In FIG. 1 is shown by way of example a telephone 1 according to the invention. This telephone is a mobile telephone comprising an earphone 2, a display 3, a keyboard 4, a microphone 5, an antenna 6, and a microprocessor 7 which ensures its operation and which notably permits of implementing a method according to the invention for
