DE2100457A1 - Method and device for coupling and / or separating signals on subscriber lines - Google Patents

Description

PATENT ANWAL ₁ Tf
DR. MOLLER-BORg. DR Manitz - DR. DEUFBL ^ ^{7 'M 1S 1?}

DiPL-ING-FINSTERWALD-DIPL-ING-GRAMKOW 7 1 Λ /. Q

β MÖNCHEN 22, ROBERT-KOCH-STR. 1 * - I U 7 O

TELEPHONE 225110

ZELLVEGER AG Apparatus and machine works Uater Oh 8610 Tjßter / Switzerland

Method and device for decoupling and / or separating signals on subscriber lines /

The invention relates to a method and a device for decoupling and / or separating

Signals on subscriber lines. |

Different types of signals appear on subscriber lines of automatic telecommunications systems, sometimes simultaneously, partly one after the other. Such signals are used, for example, to determine the line status, that is to say Occupancy or hight occupancy, expressed. Other signals are used to select one to be called Participant and other signals are used to determine the call fee to be paid, etc.

Purely specific tasks, for example for periodic monitoring of the operation of a telecommunications system or the central equipment, or for the monitoring and, if necessary, registration of the Duration of the connections initiated by a participant, the conversations he has made and the associated taxis, or the calls made to him and conversations etc. it is often desirable at least

^{10 βΜ /}

_ 2 -

individual of said signals to be decoupled from a subscriber line in this way and / or to one another separate that -thereby the proper puncture of the Telephone system is not adversely affected. From this G-round the coupling becomes advantageous in relation to the line impedance made high impedance and / or also made as symmetrical as possible.

In terms of frequency, some of the signals mentioned do not differ at all, or at least only slightly, from one another and they also have low frequencies, for example 50 Hz and below. It is disadvantageous Therefore, the separation of such signals due to their frequency difference by means of resonance circles only with considerable effort and in the case of their frequency equality is therefore not feasible at all.

The invention is based on the object of avoiding this disadvantage and a method and a device to create an economic solution to the problem of decoupling and / or separation of signals Subscriber lines.

109833/1304

The invention relates to a method for decoupling and / or separating signals on a subscriber line, characterized in that a different output signal is obtained when the loop is open or closed by comparing the potential on at least one wire of a subscriber line or a potential derived therefrom with a reference potential is, from which the one hand by a frequency selection state of the availability or non-availability of a subscriber line corresponding output signal is formed and / or the other hand, a Vfahlimpulsen corresponding to the subscriber line output signal is generated.

109833/130 «

The invention also relates to a device for implementation of the method according to claim I, characterized by one with at least one wire of the subscriber line Potential comparison device whose output ^ is galvanically connected via a low-pass filter on the one hand is connected to an output terminal via a frequency-selective switching element, which is connected to a corresponding to the occupancy or light occupancy status Output signal is applied and its output on the other hand via a high-pass filter and / or via a from the output signal of the frequency-selective switching element if it is occupied, another switching element that is controlled to be permeable is connected to another output terminal which is applied with a signal corresponding to the dialing pulses on the subscriber line is.

109833/1304

, With reference to the accompanying drawings, the invention explained using an exemplary embodiment.

It shows

Pig »1 is a block diagram of a simple embodiment

Pig. 2 shows a block diagram of a further exemplary embodiment

Pig. 3 is a block diagram of an input part of a

Device ^

Fig. 4 is a detailed circuit diagram of an input section after Pig. 3.

109833/1304

- Before an embodiment of the invention in detail is described, some are intended to open to a calling subscriber or a called subscriber whose subscriber line occurring states, 'for example can be specified. In this context it should be pointed out that the currently used Telecommunication systems sometimes have different characters. The method or device described later however, a person skilled in the art can always use the system parameters present to execute it adjust.

A) Conditions at the calling subscriber Al ^ Hichtbelichtung: that means open loop, potential between the wires a and b of the subscriber line is equal to the emf of the battery.

A2) Handset picked up: that means loop closure = occupancy, potential between wires a and b of Subscriber line is reduced by a defined amount. Due to the line symmetry and the symmetrical infeed of the battery voltage via the feed bridge is the change in potential on each Cores of the same size and the changes in potential on both cores are directed in opposite directions.

A3) Lobster selection: loop breaks in rhythm of the set lobsters result in corresponding po-

109833/1304

potential jumps on the subscriber line between the state A1 and A2, these potential jumps occur for example with a frequency of about 8-12 Ha. They are called election impulses.

A4) Call control signal: The tone of the control center becomes the calling one Participant audio frequency impulses with a frequency of 400 Hz in the rhythm of the called Subscriber outgoing call signals routed.

A5) Called subscriber lifts the handset: This causes the control center to give the first tax impulse to the calling party Participant to send out. This tax pulse can be an alternating current pulse with 50 Hz, which earth is given simultaneously on the subscriber line. But it can also be, for example, 12 kHz or 16 kHz pulse, which is given balanced to ground on the subscriber line. The duration of a such a taxi pulse is, for example, 200 milliseconds.

A6) Conversation: The conversation signals are tone-frequent and directed in opposite directions on the two wires a and b.

A7) "* End of call: This is indicated by hanging up of the handset by the calling party. This causes the loop to open, i.e. the

109833/1304

- 8 state of sewing, Al, a.

B) Conditions at the called subscriber Bl) Non-occupancy: V / ie at Al

B2) Incoming call: AC voltage signal 25 or. 50 Hz between wires a and b. Depending on the system, the signal can either be on wire a or b or be present on both wires.

B3) Called subscriber picks up the receiver: This means that his subscriber line goes into the seizure state over, see A2.

B4) Conversation: see A6

B5) End of conversation: It is marked with the called subscriber by hanging up his handset, whereby the state of non-occupancy, see Bl, is restored on his line.

109833/1304

Fig. I shows a block diagram of a simple out- management example in which only a display of the occupancy and / or Hichtbeligung, as well as the dialing pulses is provided. The wire is via lines la or Ib a and b of a subscriber line 1 with the inputs

ein__freauenzselektiven _ι switching element 2 .bzw. 2. ' ^

2a or 2SL ¹ YJe "of a ^ Tielfpassfil ^ ri" * 2 ^{'or 2 1} ' connected.

The cut-off frequency of the low-pass filter 2 or 2 'is expediently chosen only so high that except the long-lasting occupancy or non-occupancy ™ Only the dialing impulses resulting from the periodic loop opening during the election are allowed to pass are, for example, equal to about 10 Hz. Those corresponding to the open or closed loop Potentials on wires a and b are fed through the aforementioned low-pass filters 2, 2 'to inputs 5a and 5b is supplied to a potential comparison device 5. Advantageously, between each low-pass filter

2 or 2 ¹ and the input 5a or 5 "b of the potential comparison device 5 each have a threshold device

3 can be switched. The threshold value of this threshold value device is advantageously selected to be so high that only the potential jumps occurring when the loop is opened or closed can influence the potential comparison device.

As a result of the mentioned potential jump changes an output 5c of the potential comparison device 5

109833/1304

- ίο -

the output signal U ₁ appearing there - between two defined values, for example the logical signal 1 and 0. The output signal U ₁ - thus brings the state of the open or closed loop or respectively. the non-occupancy and the occupancy for the expression as well as the dialing impulses. These signals representing certain states on the subscriber line 1 are thus decoupled from the subscriber line 1, but not yet separated from one another.

The separation of the occupancy or non-occupancy signals

The signal can for example be carried out by means of a further frequency-selective signal element, for example a _y ^ low-pass filter 22, the cut-off frequency of which is, for example, 1 Hz and thus does not allow the rapid dialing pulses to pass. The output signal TJp. is fed from the output 5c of the potential comparison device via a line 20 to an input 21 of this further low-pass filter 22. At an output terminal 23 only logical signals 1 or 0 appear, which correspond, for example, to the status of the occupancy or the non-occupancy.

Since dialing pulses can only occur when the subscriber line is busy, the separation of the output signals U ₁ -

<£ b!
of the occupancy signals through a corresponding logic circuit.

109833/1304

For example, the output signal U ₅ can be fed from the output 5c via a line 31 to an input 32 of an ITAND gate 33. Another input 34 of the ITAITD gate 33 is connected to the output glue 23 via a line 35, whereby the input signal U 1 is fed to it. As a result, the NAITD gate 33 is only switched to be conductive in the occupied state and thus the dialing pulses that may occur in this state are allowed to pass through the ITAND gate 33. These logic signals U_ corresponding to the dialing pulses are available to a further output terminal 36.

Fig. 2 shows a block diagram of a further embodiment the invention. The device is intended for this, except for the occupancy condition on the line indicating signals U, and the signals U corresponding to the dialing pulses also call

to decouple impulses on the subscriber line. For this purpose the same Ver earlier to state B2 sawn. The " ringing signal is an alternating voltage, the frequency of which is above the cutoff frequency of the low-pass filter mentioned in FIG. 1 and is thus blocked by those low-pass filters Capacitor 40 connected to wire b, decoupled from subscriber line 1.

109833/1304

The ringing signal occurs on the subscriber line of the called party Participant only during the state of non-occupancy on. prefer a line 41 is therefore the call signal an input 42 depending on the Output signal U, of the low-pass filter 22 controlled switching element 43 is supplied. The switching element 43 is to this via a line 44 from the output terminal 23 of the Low-pass filter 22 whose output signal U is fed to a control input 45. In addition, the switching element 43 is chosen so that it is connected to the output terminal 23 lying signal U. is switched permeable only in the state of the unoccupied subscriber line. A NAND gate, for example, is suitable for this. At the Output 46 of switching element 43 then only appears a signal corresponding to the call signals.

In an analogous manner , further AC voltage signals on the subscriber line, for example tax pulses, can be decoupled from the subscriber line by alternating voltage couplings, for example resonance circuits, which are connected to one or both wires of the subscriber line 1 and, if necessary, via others depending on the occupancy status on the subscriber line, i.e. depending on the subscriber line of the output signal U. of the low-pass filter 22, controlled switching elements on separate output terminals, are performed.

109833/1304

The duration of a standstill on the subscriber line can vary within wide limits. In practice, the minimum occupancy time T that has yet to be recorded is. at about 1 second, which results in a highest occupancy frequency f of about 1 Hz. The cutoff frequency of the mentioned further frequency-selective switching element 22, for example a low-pass filter _} is therefore expediently assumed to be approximately 1 Hz.

From the obtained by the potential comparison output U ₁ - can be a polling pulses corresponding output signal U ₁ are also obtained in that at the output of the potential comparing device 5c 5 resulting from passage signal U, - filter through high pass either through the controlled switching element 33 or is fed directly to the output terminal 34. Here, a value between the frequency of the dialing pulses and the highest occupancy frequency f is expediently to be selected for the cutoff frequency of the high-pass filter. 3 shows a block diagram of an input part of the device. This input part includes the coupling to the subscriber line 1 by means of the two lines la and Ib and the connected low-pass filters 2 and 2 ', the threshold value devices 3 and 3 ¹ »and the potential comparison device 5. The output signal U _{5 of} the potential comparison device 5 is at a terminal 5c available. One as IJull potential

109833/1304

'Busbar serving line 7 is at a +20 volt Tapping of the supply battery connected.

As a result of the usual symmetrical feeding of the battery voltage into a subscriber line the transition of the subscriber line from the unoccupied one State to occupied and vice versa from the occupied state to the unoccupied state through on the two Cores a and b oppositely directed potential jumps noticeable. The polarity of the wires a and b with respect to The feeding of the subscriber line is known not to be carried out uniformly in different telecommunications networks. Like from Pig. 3 can be seen, it is a symmetrical circuit arrangement, the one Part of the circuit arrangement via line la to wire a and the other part of the circuit via line Ib is connected to wire b.

Each of the two threshold value devices 3 and 3 'has a defined threshold value which ^{must be effective at its input 3a or 3a 1} so that the output potential U. or Ui changes abruptly at its output 4 or 4'. A certain required voltage _{value U 2} or UA for the response of the downstream threshold value devices corresponds to this threshold value mentioned at the input 2a or 2a ^{1 of} the low-pass filter 2 or 2 ^f. If in a certain application the when changing the occupancy status

109833/1304

every potential jump occurring in wires a and b is at least 11 volts, for example, it is advantageous to select the threshold value of the threshold value devices 3 or 3 so that the voltage value U ₂ or UI required for the threshold device to respond is also 11 volts The level of the threshold value at the input of the threshold value devices 3 or 3 ″ is then lower by the voltage drop in the low-pass filter 2 or 2 *. λ

As Schwellvertvorrichtung 3 and 3 * for example, a direct-coupled amplifier can be used, which is dimensioned in known manner such that its switching state is changed when reaching the threshold value at its input * In a device according to Fig. 3 is one of the two wires a or b when changing the occupancy state on the subscriber line occurring potential jumps the output potential U _A or

Ui change by leaps and bounds.

Whether this sudden change occurs at output 4 of threshold device 3 or at output 4 ¹ of Schwellwertvorrichtuttg 3 ^f , depends on the type of polarity selected in the telecommunications network of wires a and b with respect to the supply of the subscriber line. However, when the state of the subscriber line changes from non-occupancy to occupancy or from occupancy to occupancy, there will always be a change in potential on

109833/1304

Output of one of the two threshold value devices, while the other threshold value device the output potential does not change. This behavior of the device results from the fact that depending on the type of polarity of the wires a and b each one of the two threshold value devices continuously, independently remains in a defined switching position from the state of the occupancy.

The potential at the output of the one threshold device, which changes with the change in the unoccupied state of the subscriber line, is thus always offset by a constant signaling potential that is independent of the occupancy. The task of the potential comparison device 5 is to express this change in potential, which is a clear indication of the occupancy status on the subscriber line. A relay or a bistable electronic circuit connected ^{between the output connections 4 and 4 1 of} the threshold value devices 3 and 3 ¹ , for example, can be provided as the potential comparison device.

In order to achieve that the signal to be obtained, which is dependent on the status of the occupancy or the non-occupancy, is itself in the event of a susceptible interruption of the supply at least ens for one of the two states does not change

109833/130/4

It is expedient to assign the state for which it is not supposed to change to the idle state of the relay, i.e. to deliver the signal U ^ to the output U via a normally closed contact of the relay, for example.

Pig. 4 shows a detailed circuit diagram of an exemplary embodiment according to FIG. 3. In FIG. 4, the points of view and circuit elements corresponding to FIG. 5 are provided with the same numerals. Since further signals, for example alternating voltage signals, usually also occur on a subscriber line, the potential comparison device 5 can be ^{made immune to the action of alternating voltages by connecting a diode 8 or 8 1} upstream of each of the inputs 2a and 2a. About the mentioned diodes and a resistor 9 or 9 ^f present at each input 2a or 2a ', rectification of any V / echselvoltages that are present takes place, which are converted into direct voltages acting in the same sense. The potential comparison device is immune to these direct voltages, which act in the same sense. In order to protect them against possible overvoltages on the wires of the subscriber line iiu, an overvoltage arrester 10 or 10 'can advantageously be arranged at each low-pass filter 2 or 2'. In the exemplary embodiment according to Pig. 4, the threshold value devices 3 and 3 'are designed as directly coupled switching amplifiers of known Ai * t.

109833/1304

forms. As a potential comparison device 5 is in Embodiment according to FIG. 4, a relay is used with its working contact to an Äusgangskleuaae 5c There is a potential difference at the outputs 4 and 4 ' positive voltage U, - is applied.

189833/1304

Claims (1)

Claims '' A method for decoupling and / or separating signals on a subscriber line, characterized in that by comparing the potential (U ₂ ; Up) that is present on at least one wire (a; b) of a subscriber line (1) or a potential derived therefrom ( U ^; UJp with a reference potential (U ^; U ^) a different output signal (Uc) is obtained when the loop is open or closed, from which, on the one hand, by frequency selection, an output signal corresponding to the state of the occupancy or the current occupancy of the subscriber line Cl) (U] ₉ ) and / or, on the other hand, an output signal (U _w ) corresponding to the dialing pulses on the subscriber line (1) is generated. 2. Procedure according to Anepru ^ l. 1, characterized in that that when the loop is open or closed potentials prevailing on the subscriber line before the Carrying out the mentioned comparison of at least one threshold value device (3, 3 ') are fed. 3. Method according to claim 1, characterized in that from the output signal (Uc) obtained by comparison, on the one hand, by means of its passage through a further low-pass filter (22), an output signal (U _b ) indicating the occupancy status on the subscriber line (1) and, on the other hand, by means of it Passing through a high-pass filter an output signal (U _w ) indicating the dialing pulses on the subscriber line is obtained. 109833/1304 _{· Method according to one of the preceding claims, characterized in that an output signal (U 13} ) indicating the occupancy status on the subscriber line (1) is obtained from the output signal (Uc) obtained by comparison, on the one hand by means of its passage through a further low-pass filter (22) and on the other hand, after the output signal (Uf) obtained by comparison has been passed through a switching element (33) that is permeable to the occupancy state indicating the output signal (U ^) in the occupied state and displays the dialing pulses. of the output signal (U _y ) is formed 5 · Method according to one of the preceding claims, characterized in that an alternating voltage Signal occurring on at least one of the wires (a, b) of the subscriber line via an alternating voltage coupling (40) and / or via frequency-selective means from the relevant wire (a; b) decoupled and via a dependent of the output signal (U ^) which indicates the occupancy status on the subscriber line (1) (43) is delivered. 6. Device for carrying out the method according to one or several of the preceding claims, characterized by one with at least one wire (a, b) of the subscriber line (l) via a low-pass filter (2 $ 2 ') galvanically connected totentialver ^ rental device (5), the output (5c) of which is connected on the one hand via a frequency-selective switching element (22) to an output terminal (23) to which an output signal (U ^) corresponding to the occupancy or non-occupancy state is applied and whose Output (5c) on the other hand via a high-pass filter and / or via a Tom Auegangssignal (U ^) of the frequency-selective ^ Switching element (22) when occupied, permeable controlled 109833 / 130A Another switching element (33) is connected to a further output terminal (36) which is connected to one of the dialing pulses corresponding signal on the subscriber line (U) is applied. 7. Device according to claim 6, characterized by at least one series circuit of a low-pass filter (2 or 2 ') and a threshold value device (3 or 3') which series circuit is connected on the input side to a wire (a or b) of the subscriber line (1). _} den (1a, 1b) and which on the output side is connected to an input (5a or 5b) of the potential comparison device (5). 8. The device according to claim 6 or 7 »characterized by an AC voltage coupling (40) connected to at least one wire (a, b) and / or frequency-selective means for decoupling AC voltage signals (hoof, taxe, hoof control) from this wire (a, d is performed b) and a series-connected to controllable switching element (4-3) _t at its control input (4-5) at least a signal derived from the output voltage (Uc) of the potential comparison means (5) output signal (Û). 109833/1304