DE19541365A1 - Converter for analogue telephone device coupled to digital telephone network - Google Patents

Abstract

The converter includes a circuit (12-15) for converting the pulses provided from the function of a signal button (22) which is incorporated in the analogue telephone device. The pulses are converted into a signal corresponding to operation of a rest contact for short-term interruption of the loop current. The interruption lasts for a period of time which is greater than 170 ms and less than 900 ms. Preferably the converter is provided as an attachment for the analogue telephone device, connected between the line (21) and the telephone network interface.

Description

The invention relates to a converter for expansion the function of one or more analog telephone terminals on an analogue telephone connection on a digital one Switching center of the telephone network / ISDN, the analogs Telephone terminals have the function of a signal or earth have button, but no fork switch such. B. Telephone plants with the feature "sub-plant capability" or cordless phones.

It is known that analog telephone lines (AnTelAs) at digital exchanges in the telephone network / ISDN Features that can be used in previously similar Form could only be used from digital connections. These features are (among others) Block call forwarding, call waiting, inquiries / brokering and tripartite conference.

"Call waiting" is the phone call without one miss another important call. Here is a acoustic signal (the so-called call waiting tone) during a Conversation noted that another participant with want to speak to the phone user. The other participant hears no busy even though the line is already in use tone, but the dial tone.  

The feature "Queries / Brokering" is therefore actively another one besides an existing connection To establish a connection or to query a "waiting call", without disconnecting the existing connection. So that can not just alternating with two different conversation partners be called without having to hang up and redial each time need, but you can also have a second caller query even though you are already speaking.

The "three-party conference" feature enables two To make calls to the other party at the same time. This is it only required during a call using the Performance feature "Queries / Brokering" another connection to establish a second interlocutor. After that needs the corresponding command for the Three-way conference to be entered into the terminal.

To use the "Inquiries / Brokering" or "Three-way conference" is usually one with "hook flash" designated function key on the terminal equipment (telephone apparatus) is required. However, if the function key mentioned should not be available on the respective device but the hook flash signal can also be tapped briefly trigger the telephone fork.

To activate / deactivate these features and So there are certain procedures for their operation and selection required with which the subscriber to the telephone service the Telephone network / ISDN communicates its requirements via the connection. In addition to dialing digits, the DTMF dialing characters "*" and "#" and a loop break of a specified duration used. This loop interruption becomes the "fork switching signal" (English: hook flash) called. As described above, for the features "Queries / Brokering" and "Threesome conference "is required Telephone network / ISDN signals that the existing (call) Ver bond should be kept to a "waiting call" to accept in consultation, to establish a consultation connection  or to broker or to an existing second connection to hold a three-way conference.

The fork switching signal is therefore an interruption of the Loop current of the telephone line during a through switched connection for a short period of time (by preference as 170 ms <t <900 ms).

Conventional terminal equipment, primarily the one up to now Cordless phones and telephone systems available on the market the "subsystem capability" feature for the analogue Telephone connections are only partially able to switch the fork generate signal. For telephones with a hook switch can switch the fork switch signal by pressing the fork switch (Fork stroke) are generated for the specified duration. With end facilities in which the hook switch operates indirectly will, such as B. for cordless phones and small phones systems, the fork switching signal cannot be generated as a rule will. The use of the "Queries / Brokering "and" tripartite conference "not at all, the performance feature "call waiting" only possible without "queries" (i.e. a It is not possible to hold the currently existing connection).

Based on the described prior art, it is the Object of the invention, the features "waiting with Queries "," Queries / Brokering "and" Three-party conference " Analogue connections of digital switching centers of the telephone network / ISDN with the majority of the currently instal end devices to use comfortably.

According to the invention, the task with a converter solved at the outset by means of conversion of the generated by the function of the signal or earth button Impulse in a fork switching signal (= brief interruption the loop current during a through connection, preferably within 170 ms <t <900 ms).

Prerequisite for a practical implementation of the Erfin  So is only the presence of a signal or Earth button on the terminal (telephone) or the Performance feature "sub-system capability" for small tele communication systems.

The basic idea of the invention can be advantageously with two alternative solutions: On the one hand, it is possible to use the funds as an additional device the telephone terminals in their connecting line to the telephone switch on the switching device. Alternatively, you can the means but also as an additional device with the coding "N on a telephone interface device of the type teluni cation interface unit (TAE) must be connected.

In an advantageous development of the invention, it is proposed that a the connection line to the telephone terminals monitoring and impulses according to the impulses of the signal or earth button on the signaling wire "E" To provide switching electronics.

The telephone subscriber thus benefits from the above ge named special features at the analog connection digi taler exchanges of the telephone network / ISDN, without themselves to have to buy a new terminal for this.

The invention can also be meaningfully there by designing that the connecting line to the phone Switching electronics monitoring terminal devices a very brief interruption of the loop current of approx. 80 ms evaluates as an impulse of the signal button.

According to a particularly preferred embodiment of the invention the switching electronics according to the invention has an input circuit for detecting the impulse of the signal or earth button, a Schmitt trigger connected downstream of the input circuit, one monostable multivibrator downstream of the Schmitt trigger and a switching stage downstream of the monostable multivibrator to interrupt the loop current.  

To malfunctions of the switching electronics according to the invention To avoid from the outset, it is proposed that the one circuit of the switching electronics with the detection of short consecutive pulses corresponding to the pulses the signal or earth button for a short period of time is equipped.

After detection of a pulse the signal or earth button is pressed this detection for a certain, over the duration of the sub interruption of the wiper current blocked, to a double interruption of the loop current at long pressed, bouncing or too impatiently pressed Avoid signal or earth button.

In a further development of the invention, it is also advantageous during the period of interruption of the loop current through the monostable multivibrator feed to the terminal equipment to lay. Because it cannot be guaranteed that all terminal equipment in the event of an interruption in the supply for the stated period of time maintains the previous operating state hold.

Further embodiments of the invention are set out in claims 9 and 10 removable.

The invention is now based on a block circuit illustrated embodiment illustrated and explained below.

The converter according to the invention or the embodiment of the same, which is visible from the drawing, has a total of 10 be. Furthermore, 20 denotes an analog telephone device, for. B. a simple telephone with signal or earth key 22 , a cordless telephone with signal or earth key or a telephone system with the feature "subsystem capability". The terminal 20 is closed via a connecting line 21 to a telephone connection device 30 . Between the connecting line 21 and the telephone connection device 30 , the converter 10 is then looped in via circuit conductors 11 and 16 . This can e.g. B. done so that a plug of the type TAE 6F, which is attached to the connection line 21 of the telephone terminal 20, is pulled from a TAE 6F socket in the telephone connection device 30 and is inserted into a TAE 6F socket of the converter 10 , which is attached to the input of the converter 10 or to the connecting line 11 . The connecting line 16 of the converter 10 is accordingly equipped with a plug of the TAE 6F type, which is inserted into the TAE 6F socket in the telephone connection device 30 .

As the drawing also shows, the con verter 10 contains switching electronics 12 to 15 , which can be designed as an additional device. As an alternative to this, the switching electronics 12 to 15 can also be closed as an additional device with the coding "N" on the telecommunications interface unit (TAE).

Towards monitored to ground means 20, the switching electronics 12 to 15 the connection line 11 and evaluates pulses one at the end means 20 provided and numbered with 22 signal button on the signaling wire "E" from.

In particular, the switching electronics 12 to 15 consists of an input circuit 12 for signal detection, a Schmitt trigger 13 connected downstream thereof, which operates on a downstream monostable multivibrator 14 . Finally, the latter is followed by a switching stage 15 .

The hook switch signal ("hook flash") is activated via the already mentioned signal key 22 of the terminal device 20 . The actuation of the signal button 22 is recognized in the input circuit 12 of the switching electronics 12 to 15 as a pulse signal. The Schmitt trigger 13 has the function of causing a steeper rising edge of the signal level to trigger the monostable flip-flop 14 . The set switching threshold also hides interference levels that can be caused by GU operation or WaH key (speakerphone mode).

The duration of the monostable multivibrator 14 can be set in the range between 170 and 900 ms. The hook-up signal is generated via the downstream switching stage 14 , ie the loop current of the connection to the exchange is interrupted for the set period of time. Towards the terminal device 20 , supply is applied for this period of time, since it is not ensured that all the terminal devices maintain the previous operating state if the supply is interrupted for the stated period of time.

To a - e.g. B. with longer pressed signal key 22 possible - to avoid possible double hook flash, the input circuit 12 is designed so that after the detection of a pulse, the signal evaluation is temporarily blocked.

Claims (10)

1. Converter ( 10 ) for expanding the function of one or more analog telephone terminals ( 20 ) on an analog telephone connection at a digital exchange of the telephone network / ISDN, the analog telephone terminals ( 20 ) having the function of a signal or earth key, but no hook switch, such as telephone systems with the feature "under system capability" or cordless phones, characterized by means ( 12-15 ) for converting the pulse generated by the function of the signal or earth button ( 22 ) into a hook-up signal (= brief interruption of the loop current during a switched connection, preferably within 170 ms <t <900 ms). 2. Converter according to claim 1, characterized in that the means ( 12-15 ) as a set to the telephone terminals ( 20 ) in their connection line ( 21 ) to the telephone connection device ( 30 ) are switched on. 3. Converter according to claim 1, characterized in that the means ( 12-15 ) are connected as an additional device with the coding "N" to a telephone connection device of the type telecommunication connection unit (TAE). 4. Converter according to claim 1, 2 or 3, characterized in that a connecting line ( 11 ) to the telephone terminals ( 20 ) monitoring and pulses corresponding to the pulses of the signal or earth key ( 22 ) on the signaling wire "E" evaluating Switching electronics ( 12-15 ) is provided. 5. Converter according to one or more of claims 2-4, characterized in that the connecting line ( 11 ) to the telephone terminals ( 20 ) monitoring switching electronics ( 12-15 ) a very brief interruption of the loop current of about 80 ms as The pulse of the signal button ( 22 ) is evaluated. 6. Converter according to claim 4 and / or 5, characterized in that the switching electronics ( 12-15 ) an input circuit ( 12 ) for detecting the pulse of the signal or earth key ( 22 ), one of the input circuit ( 12 ) downstream Schmitt trigger ( 13 ), a Schmitt trigger ( 13 ) downstream monostable multivibrator ( 14 ) and one of the monostable multivibrator ( 14 ) downstream switching stage ( 15 ) for interrupting the loop current. 7. Converter according to claim 6, characterized in that the input circuit ( 12 ) of the switching electronics ( 12-15 ) is equipped with a short-term restraining the detection of short successive pulses corresponding to the pulses of the signal or earth button ( 22 ). 8. Converter according to claim 6 or 7, characterized in that during the period (t) of the interruption the loop current through the monostable multivibrator ( 14 ) supply is placed on the terminal device. 9. Converter according to claim 6, 7 or 8, characterized in that the energy supply to the switching electronics ( 12-15 ) is taken from an external voltage source. 10. Converter according to one or more of claims c-9, characterized in that the power supply to the switching electronics ( 12-15 ) is removed from the telephone connection line ( 16 ).