DE20108562U1 - Subscriber-side service completion module of an ISDN communication system with extended features - Google Patents

Description

Subscriber-side line termination module of an ISDN communication system with extended performance features.

The invention provides a subscriber-side line termination module (NT module) in an ISDN communication network which, in addition to the conventional tasks of the NT module, offers additional communication components, such as the possibility for a caller to connect himself to a subscriber of the NT module or to a subscriber in the public telephone network after prior identification.

Description Page 1

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The present invention relates generally to integrated service digital communication systems, so-called ISDN systems, and in particular to improvements in their subscriber-side line termination module, the so-called NT module or network termination module. ISDN communication systems are systems that use a digital network for the simultaneous transmission of voice and data. They have become increasingly widespread in recent years. On the subscriber side, the line running from the exchange to the subscriber is terminated with a subscriber-side line termination module, a so-called NT module. Digital and analogue terminals, which can consist of a telephone, answering machine, fax or modem, can now be connected to this NT module.

With an ISDN connection, it is usual for the user to have at least three phone numbers available on the NT termination module, two of which can be used simultaneously. This is used by many NT module manufacturers, among other things, to provide programmable call forwarding. It is also known that this call forwarding is remotely programmable. This means that the authorized user can enter a phone number in the public or mobile network when calling his NT module, to which an incoming call to the said NT module is forwarded. This method is to be expanded in the present invention by an additional component.

With the mobile phones that are very common today, it is sometimes not possible to make calls abroad because special activations are required for this. It is also known that various options are offered that allow mobile phone users to make calls at particularly low cost. For example, choosing a fixed number or the city option. The present invention aims to improve these disadvantages (no calls abroad) and advantages (low-cost call options) by linking two phone calls into one. For example, a call with a mobile phone to the caller's ISDN home connection and then an additional connection set up by the mobile phone caller over the second line of the ISDN connection to the actual desired caller.

In order to better understand the function of this invention, a short example of use is given here.

Description Page2

The caller is defined as a special user by the NT module (1) to be called by previously storing his telephone number in the special telephone number memory (6) of the NT module and, when a call is made to the said NT module (1), is recognized as a special caller by the caller ID (5) based on the transmission protocol of his telephone number and the call is automatically accepted.

Variant 1. Call without special use: A voice call is made, the TN module (1) identifies the caller as a special user and answers the call without a ring tone being heard on the called telephone. After the call is automatically accepted, an adjustable waiting time of around three seconds begins. During this waiting time, a terminal adapter (8) registers whether the caller is transmitting any further DTMF (multi-frequency dialing) dialing signals. If this is not the case, the main control device (4) initiates the ringing alarm and the called subscriber can answer the call.

Variant 2. Call with special use: A voice call is made as described in variant 1, but after the call has been set up, the caller transmits a telephone number in the form of DTMF pulses within the adjustable waiting time until the tone alarm is triggered. This is recognized by the terminal adapter (8), made known to the main control unit (4), and the telephone number is stored in the ringer buffer (7) after the terminal adapter (8) converts the DTMF pulses into a digital dialing signal. A tone alarm is not triggered on the called telephone with this type of call. After the main control unit (4) has registered that a telephone number has been transmitted to it, it switches the second exchange line to the "off-hook state" and, after the dial tone has been heard, transmits the previously buffered ringer to the digital signaling channel of the ISDN. After the telephone number has been transmitted, the main control device (4) connects both lines together so that the waiting special call user now hears the ringing tone of the connected line and can have a normal telephone conversation with the called party after accepting the call. Using this method, almost all services of the public telephone network can also be used with a mobile phone.

It is also possible to set up the NT module (1) in such a way that specified special users have the option of forwarding themselves to an internal telephone system after answering a call by transmitting a flash signal or a DTMF identification.

Variant 3. Call with special use: A voice call is made to the number belonging to the NT module (1) that is used exclusively by special callers. This means to a number that does not have its own terminal such as a fax, telephone or answering machine. In this case, a call to this number is only accepted if the caller's number is defined as a special user and if a free line is available with which a further connection can be established or an internal forwarding connection can be set up. The free line can

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Description Page3

When a special caller calls, the call is immediately switched to the "off-hook" state so that the DTMF identification is converted in the terminal adapter (8) and can be forwarded without intermediate storage.

The NT module described can contain the well-known features such as saving call data, restricting calls to specific numbers, restricting calls to specific times of day or creating a speed dial memory.

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Reference list

1 Intelligent N T module

2 U interface

3 S interface

4 Main control device

5 NumberfnidsWizer

6 special foot number memories

7 Phone number buffer

8 Terminal adapters

9 A/D converter

10 Analogue connection

Claims (7)

1. Subscriber-side line termination module (NT module) ( 1 ) for the integrated services digital network (ISDN) with a main control device ( 4 ), a U interface ( 2 ), an S interface ( 3 ), a terminal adapter ( 8 ), a special call number memory ( 6 ), a call number buffer ( 7 ), a call number identifier ( 5 ) and optionally an A/D converter ( 9 ) and an analog connection part ( 10 ), characterized in that an automatic call acceptance takes place for callers stored in the special call number memory ( 6 ), and these have the option of setting up a further connection. 2. Line termination module according to claim 1, characterized in that it has external display and control elements or a PC interface, or has the possibility of entering or defining telephone numbers in the special call number memory ( 6 ) using a telephone, which then have the status of the special caller. 3. Line termination module according to one of the preceding claims, characterized in that the recognition of the special callers is carried out on the basis of the ISDN transmission protocol (transmitted telephone number of the caller) and/or on the basis of a code to be transmitted by the caller and transmitted by the DTMF (multi-frequency dialing method). 4. Line termination module according to one of the preceding claims, characterized in that when a special caller calls, an adjustable time elapses during which it is checked whether the special caller wishes to be connected to the dialed number or whether he wishes to establish another connection via a free line, during which time no call signaling takes place to the dialed terminal. 5. Line termination module according to one of the preceding claims, characterized in that the request of a special caller for a forwarding is made by transmitting the additional desired telephone number in the form of DTMF, this is recognized by the main control device ( 4 ), the telephone number is converted by the terminal adapter ( 8 ) into digital dialing signals for the ISDN, the telephone number is stored in the telephone number buffer ( 7 ), at the same time the main control device ( 4 ) sets the second line to the "off-hook" state, then the additional desired telephone number stored in the telephone number buffer ( 7 ) is output to the free line, and then both lines are connected together. 6. Line termination module according to one of the preceding claims, characterized in that the telephone number desired by the special caller can be an internal or an external (exchange) telephone number. 7. Line termination module according to one of the preceding claims, characterized in that the function of the telephone number identifier ( 5 ) is in the form of a program which is processed by the main control device ( 4 ).