GB1560210A - Subscriber number transmitter for a telecommunications system - Google Patents

Description

(54) A SUBSCRIBER NUMBER TRANSMITTER FOR A TELECOMMUNICATIONS SYSTEM (71) We, SIEMENS AKTIEN GESELLSCHAFT, a German Company of Berlin and Munich, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement::- This invention relates to a subscriber number transmitter for a telecommunications system, in particular a telephone system, wherein a subscriber number can be selected by a subscriber and an automatic repeated transmission of the subscriber number can be selectively effected and wherein the subscriber can input at least one additional code signal at arbitrary points between consecutive digit selections of the subscriber number and when the additional code signal is identified the transmission of the subsequently selected portion of the required subscriber number is delayed for a predetermined length of time.

It is known to be necessary to input an additional code signal, also referred to as a pause signal, by means of a pause key when a dialling tone must be awaited between the individual digit selections of a subscriber number. This is the case for example when selecting the number via a private PBX exchange when, following the selection of the external exchange code number (e.g.

"0" or "1 1"), it is necessary to wait for the dialling tone response from the exchange before continuing to select digits. The time it takes for the dialling tone to become audible can be as much as 3 secs., for example. If a subscriber number selected on a pusnbutton telephone having automatic repetition facilities, is repeated due to the depression of a push-button or key, then following the transmission of the external exchange code number an interval of, e.g.

approximately 3 secs, must be provided as comparison with the normal interdigit interval of 0.8 secs used in automatic repeated transmission.

If the subscriber to such a conventional telephone system wishes to have the option of automatic number repetition, then having selected the external exchange code number and upon hearing the dialling tone he must actuate a pause key before actually continuing to select digits. If he omits to operate the pause key, subsequent repeated number transmission will lead to a misconnection since the subscriber number transmitter transmits the digits with the shortest possible pauses between them and therefore some of the transmitted digits are lost.

The disadvantage of the known subscriber number transmitters consists in that having heard the dialling tone, the subscriber must always actuate a pause key before continuing to select digits. This is found to be extremely difficult to remember, at least initially, by any subscriber accustomed to normal subscriber apparatus and frequent misconnections can occur.

According to the present invention there is provided a subscriber number transmitter for a telecommunications system, and in which a subscriber number can be selected by a subscriber and an automatic repeated transmission of the subscriber number can be selectively effected, means being provided for enabling the subscriber to input at least one additional code signal at an arbitrary point between consecutive digit selections of the subscriber number, means being provided for identifying the additional code signal and delaying the transmission of the subsequently selected portion of the required subscriber number for a predetermined length of t'me during subsequent automatic repeated transmission of the number, the additional code signal being automatically input for use in subsequent automatic repeated transmission when the subscriber exceeds a predetermined delay time between the selection of two consecutive digits.

In one embodiment the overshooting of the predetermined delay between the selection of two consecutive digits only leads to an automatic input of the additional code signal for interdigit delays up to a predetermined digit position in the subscriber number. Also, for each selected subscriber number, the number of said additional code signals which can be input may be restricted to a predetermined maximum. The provision of either or both of these latter features avoids the need for unnecessary storage space should the subscriber carry out the dialling too slowly, and in the event of automatic repeated transmission avoids an unnecessarily slow transmission of the subscriber number.

In another embodiment the automatic input of the additional code signal takes place only when the overshooting of the predetermined delay is accompanied by a response characteristic signal being detected during the time interval which exceeds said predetermined delay.

In this embodiment a pause is automatically inserted when the length of time between the first and second digit selections in the case of a one-digit external exchange code number or between the second and third digit selections in the case of a two-digit external exchange code number exceeds a predetermined delay time, for example 2 secs, and a response characteristic signal has been received during the relevant interdigit time interval.

Therefore, this embodiment avoids the insertion of unnecessary pauses when the subscriber selects digits too slowly, so that in the case of an automatic repeated transmission the subscriber number is not transmitted with unnecessary pauses.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figs. 1 and 2 are block circuit diagrams of subscriber number transmitters respectively embodying this invention.

Fig. 1 illustrates only those parts of a subscriber number transmitter which serve to describe the embodiment of invention, namely a keyboard T, a store Sp, a converter U and a timer ZG. At the commencement of each key depression to select a digit the timer ZG is started. If the length of time between two consecutive key depressions exceeds a predetermined delay time, for example 2 secs., the output of the timer supplies a signal which leads to the input of a pause signal into the store Sp.

In the event of an automatic repeated transmission of the selected subscriber number, this pause signal is recognised as such by the converter U, which serves to convert the code signals stored in the store Sp into subscriber number pulses for transmission. As a result of the pause signal recognition the transmission of the subscriber number pulses is held up for a predetermined length of time, e.g. 3 secs.

In the subscriber number transmitter illustrated in Fig. 2, an audible tone receiver HTE and an AND-gate A are additionally provided to the transmitter shown in Fig. 1.

At the commencement of each key depression the timer ZG is started. If the length of time between two consecutive key depressions exceeds a predetermined delay time, for example 2 secs., the output of the timer supplies a signal to an input of the AND-gate.

At the start of each key depression, the audible tone receiver HTE is simultaneously enabled for operation. The audible tone receiver HTE can consist of a simple frequency detector which detects an audible tone frequency of e.g. 425 Hz occuring as a characteristic signal in response to the digits so far selected e.g. forming an external exchange code number. The audible tone receiver HTE is not required to differentiate between dialling tone and engaged tone since this is done by the subscriber himself during the initial number selection. If the audible tone frequency is received by the audible tone receiver HTE during the time interval which exceeds the Predetermined delay time, a signal is supplied from its output. This signal is supplied to the second input of the AND-gate.This ensures that the output signal from the timer is only forwarded to the store Sp when a response characteristic signal has been received during the relevant time interval exceeding the predetermined delay time and only in these circustances is an additional code signal, or pause- signal, input into the store Sp.

In the case of an automatic repeated transmission of the selected number, this additional code signal is recognised as a pause signal by the converter U and the transmission of the subscriber number pulses is held up for a predetermined length of time, e.g. 3 secs as with the embodiment shown in Fig. 1.

As mentioned above, embodiments can be provided in which the overshooting of the predetermined delay between the selection of two consecutive digits only leads to an automatic input of the additional code signal for interdigit delays up to a predetermined digit position in the subscriber number. Also, for each selected subscriber number, the number of said additional code signals which can be input may be restricted to a predetermined maximum.

Thus in the embodiments described above a pause is automatically inserted when the length of time between the first and second digit selections in the case of a one-digit external exchange code number, or between the second and third digit selections in the case of a two-digit external exchange code number, exceeds a given length of time, for example 2 secs. It is ensured that this time occurs automatically when the subscriber is waiting for the dialing tone. In the subscriber number transmitters described above, when the subscriber has received the dialling tone, he can immediately proceed to select further digits without operating a pause key. Due to the fact that the subscriber can select a subscriber number in the normal manner and nevertheless the necessary pause is inserted by the subscriber number transmitter during automatic repetition, misconnections are avoided.

WHAT WE CLAIM IS: 1. A subscriber number transmitter for a telecommunications system and in which a subscriber number can be selected by a subscriber and an automatic repeated transmission of the subscriber number can be selectively effected, means being provided for enabling the subscriber to input at least one additional code signal at an arbitrary point between consecutive digit selections of the subscriber number, means being provided for identifying the additional code signal and delaying the transmission of the subsequently selected portion of the required subscriber number for a predetermined length of time during subsequent automatic repeated transmission of the number, the additional code signal being automatically input for use in subsequent automatic repeated transmission when the subscriber exceeds a predetermined delay time between the selection of two consecutive digits.

2. A subscriber number transmitter as claimed in Claim 1 wherein said additional code signal is input automatically only for delays between digit selections occurring before a predetermined digit position in the subscriber number.

3. A subscriber number transmitter as claimed in Claim 1 or Claim 2 wherein for each selected subscriber number, the number of said additional code signals which can be input automatically is restricted to a predetermined maximum.

4. A subscriber number transmitter as claimed in any one of the preceding Claims wherein an automatic input of the additional code signal is only effected when the predetermined delay time is exceeded and a response characteristic signal has been received during the time interval between digit selections which exceed said predetermined delay.

5. A subscriber number transmitter as claimed in any one of the preceding Claims wherein a store is arranged to store said selected number for said automatic repeated transmission and the input of said additional code signal is into said store.

6. A subscriber number transmitter for a telecommunications system and substantially as described herein with reference to Fig. 1 or Fig. 2 of the accompanying drawings.

7. A telecommunications system including a subscriber number transmitter according to any one of the preceding

Claims (1)

1. Claims.