DE1102827B - Method and arrangement for improving the crosstalk attenuation and the interfering distance in toroidal core evaluation fields in telecommunication systems, in particular telephone systems - Google Patents

Description

Method and arrangement for improving the crosstalk attenuation and the signal-to-noise ratio for toroidal evaluation fields in telecommunication systems, especially telephone systems It is known in telecommunications, in particular telephone systems for subscriber identification To use toroidal fields. In these core fields, the subscriber numbers Evaluation loops through one of the digits of the subscriber call number Number of cores out, these having the function of jumper rings and transformers take over. So z. B. in a field with three columns and ten rows with a total thirty toroidal cores a total of a thousand clearly distinguishable, three columns each inclusive core combinations are formed.

This technique assumes that there is only one loop of the field at a time is effectively switched through, otherwise more than three cores will be magnetized and therefore no clear assignment of the individual core combinations can be identified. In the known arrangements, therefore, simultaneous requests. one after the other processed by using a contact pyramid corresponding to the calling subscribers Loops individually one after the other to mark the associated core combination a generator to be closed.

On the other hand, it is possible to have one or both ends - depending on the type of Supply - the evaluation loops threaded through the core field via coupling elements to be firmly connected to the wires of the connecting line and through the individual office transmissions assigned identification contacts, which in this case simultaneously via the subscriber line and the associated evaluation loop running marking circuits over a to close all office transmissions common test generator individually one after the other.

The practical realization of this possibility has come up so far Difficulties: Due to the fixed connection of the evaluation loops to the subscriber connection lines namely exists over the subscriber circuit or over the feed bridge of the office transfer simultaneously a number of parallel AC circuits. The inductive coupling of the individual core loops is of considerable influence on the size of the Crosstalk attenuation and the signal-to-noise ratio. The size of the crosstalk coupling and the signal-to-noise ratio - distance between the useful signal at a marked Core and the interference voltage at any core of the evaluation field - is included essentially dependent on the voltage division between the effective inductive Coupling resistance of the cores common to the individual loops and the coupling resistance.

The present invention now relates to a method that it enables the influence of inductive couplings on the crosstalk attenuation and in particular to limit the interference voltage to a minimum or to avoid it entirely. This is achieved in that switching means assigned to each individual toroidal core in the idle state, the transforming properties of the cores, e.g. B. by pre-excitation or short-circuit of a core winding.

According to a further embodiment of the invention, the control takes place Coupling inductance of the cores in that the associated with each individual core Switching means through contacts that control the connection of a test receiver Switching means are influenced, e.g. B. effectively switched on a pre-excitation winding which is switched off for the duration of the test process.

It is advantageous to control the coupling inductance with savings the pre-excitation winding is carried out using the test winding that is already present for each core, by connecting the test winding to a contact that connects the Test receiver controlling switching means is shorted and the short circuit only is canceled for the duration of the test process.

In the case of pure series testing, the only test receiver will be one after the other only switched to the core to be tested, it is so only one core at a time for the duration of the test process for the transmitter. The remaining In contrast, according to the invention, nuclei of the field are magnetically ineffective and separate as disturbing coupling points. The crosstalk influence can therefore at most originate from a single coupling point. An interference voltage influence takes place does not take place. At a z. B. Thousands core field are here for full scanning thirty scan steps required.

The same result with regard to the influence of crosstalk and interference voltage one arrives with the so-called column parallel test, with the one with several test receivers at the same time all cores of a column or part of a column and one after the other the individual columns are checked with the same set of test receivers. at a thousand kernel field are here for complete scanning at one expense three scanning steps are required for ten test receivers.

In both cases the size of the evaluation core fields has no influence on the degree of improvement in the crosstalk attenuation and the signal-to-noise ratio: The Cross-talk is only influenced by a coupling point, an interference voltage influence does not take place.

With the parallel line test, with the one with several test receivers the cores of the entire line at the same time and the individual lines one after the other are checked, however, the number of crosstalk attenuation increases with each column (decade) reducing coupling points by one and the signal-to-noise ratio is reduced from column to column approximately by a factor of 10. The use of the parallel line test is therefore practically limited to a certain core field size, e.g. B. on a field of thousands with a total of three decades, each of which corresponds to a column.

According to a further embodiment of the invention, it is still possible, too when using the parallel line test, a larger number of participants in one To summarize the toroidal evaluation field without the test being carried out in the individual Kernels induced interference voltage is falsely influenced by namely in dependence several cores from the permissible signal-to-noise ratio from a certain decade upwards The individual nuclei deliver the same evaluation result over the next decade summarized in groups within these decades and the individual groups of Are checked decade to decade offset from one another line by line, in such a way that in all evaluation loops only one of the loops common to the individual loops Cores from the specific decade upwards are magnetically effective in every test step will.

By the measure that the one or more cores of a decade formed groups from decade to decade offset against each other so that in no identification loop more than one of the in a line lying cores of the higher decades becomes magnetically effective at the same time, becomes the largest possible interference voltage component that results from the direct coupling of two or more cores lying in a row over one or more of these cores running through Identification loops originates, suppressed.

There is a crosstalk influence at the remaining coupling points takes place only for the duration of the identification process, amounts to in large telephone systems the time of reduced crosstalk attenuation is only a fraction of the total occupancy time.

The method on which the invention is based is now based on the Fig. 1 to 6 explained in detail. 1 shows one of the possible circuit arrangements for subscriber identification with over the occupied subscriber lines closed evaluation loops, Fig. 2 and 3 each have an arrangement for controlling the Coupling inductance of the individual cores by direct current pre-excitation or by Short circuit of the test winding; 4 to 6, however, show exemplary embodiments for Reduction of the interference voltage influence with staggered line testing.

Fig. 1 shows in its upper part the subscriber stations to be identified, of which, for the sake of simplicity, only those of the participants Tlaa 111 and Tlsi222 with their connection wires connected through for exchange transmission AUel or AUe2 are, and in its lower part the toroidal evaluation field, consisting z. B. from thirty Cores arranged in three columns H, Z and E of ten cores each.

Of the thousand possible core loops, only four are shown, namely those through the coresH1, Z1 and E1; H1, Z1 and E2; H2. Z2 and E2, as well as HO, ZO and E0. One end of these core loops is permanently connected via a coupling element K 111, K112, K222 or K 000 to one subscriber wire a and the other end directly to the other wire b.

For example, if the subscriber speaks subscriber 111, there are all subscribers who are also conducting a call and whose identification loops run through one of the cores H 1 or Z 1 or E 1 or via other cores through the cores H 1 or Z 1 or E 1 running loops are coupled, crosstalk coupling circuits. So is z. B. the circuit 1. Tln 111 a, K 111, H 1, Z 1, E 1, Tln 111 b coupled with the circuit 2. Tfiz 112a, K112, H1, Z1, E2, Tln112b via the cores H 1 and Z. 1 and with the circuit 3. Tln 222 a, K 222, H 2, Z 2, E 2, Tln 222 b via the loop assigned to the subscriber Tlra112 and the cores H1 and Z1 as well as E2 etc.

If, for example, the subscriber T1n222 is to be identified, a generator G is connected to the speech wires in the assigned exchange transmission AUe2 via identification contacts 21 and 22, thus closing the following circuit: 4. G l, 21, GW, AS, K222, H2, Z2, E2, AS, GW, 22, G 2.

In this way, interference voltage is induced in each loop that runs through the cores H2 or Z2 or E2 or is coupled via other cores to loops that run through the cores H2 or Z2 or E2. B. in circuit 5. - (AUe1), SI, GW, AS, Tln111u, K111, H1, Z 1, E 1, Tln 111 b, AS, GW, S II, earth via the loop assigned to the subscriber 112 and the Cores E 2 as well as Z 1 and H 1 etc. The consequence of this can be that when the individual cores are scanned by the test receiver, the core H 1 is identified instead of the core H2, etc.

FIG. 2 shows a section from the evaluation field according to FIG. 1 with the arrangement according to the invention. A pre-excitation winding VW I to VW 0 is assigned to each core H1 to HO, which is connected to a direct current source B via a protective resistor R in the idle state by an assigned contact sk 1 to sk 0. Such a sufficient pre-excitation makes it possible to cancel the transforming properties of the individual cores, so that all cores are magnetically ineffective in the idle state.

Only when the participant is to be identified are simultaneous with the connection of a test receiver PTl via a search selector SW through a Control chain SK the individual pre-excitation windings through the associated contacts sk 1 to sk 0 are switched off individually or in groups, depending on the type of test, and the Cores magnetically and transformatively effective for the duration of the test process. the further testing is carried out in a known manner.

Finally, FIG. 3 shows a further exemplary embodiment. The pre-excitation winding for each core was dispensed with here. The elimination of the transformative property is achieved by short-circuiting a test winding PW 1 to PW 0 via a contact sk 1 to sk 0. The individual contacts sk 1 to sk 0 are opened one after the other, depending on the control chain SK controlling the connection of the test receiver PV, and the short-circuit of the test winding is thus briefly canceled.

The connection of the test receiver during testing can be done via a Contact pyramid of a relay chain as well as a simple search selector, to which a counting chain is assigned. In the latter case, the pre-excitation or contacts controlling short-circuit windings Contacts of the counting chain relays.

Runs z. B. in an arrangement with two thousand core loops according to FIG. B. the first line a false addressing of the test receiver, not shown, of column I is possible, since the core H1 involved in the core combination 2122 to be identified is also influenced by the core 1T1 which is not involved. Namely, in the identification loop 1111 led through the cores of a single row, the hundreds and thousands cores are magnetically effective at the same time. The same also applies to the loops 2222 or 1333 or 2444 etc. up to 2000 which are respectively passed through the cores of a single row. In the arrangement according to FIG , the thousand kernels 1 T 1 to 5 T 1 lying in their row can be falsely identified. The interference voltages induced in the cores Z 1 and E 1, on the other hand, are not critical, since they are smaller by a factor of 10 or 100 compared to the interference voltage induced in the core 1T1 over a maximum of one hundred loops. On the other hand, if, as in the arrangement shown in FIG. B. 1 T 1, by the hundred core lying in the same line, z. B. H 1. The same - would come about with the arrangement according to FIG. B. begins three steps offset, so with the core 2T1 instead of 1T1.

Fig. B shows a ring core evaluation field for a total of four thousand subscriber lines. The cores of column H are also as in the embodiment of Figure 5 in five groups of two cores, z. B. 1I1 and 172 to H9 and H0 . Likewise, each of these groups is assigned a number of thousand cores corresponding to the number of thousand units, in the present example thus four thousand cores each, e.g. B. 1 T 1, 1 T 2, 1 T 3 and 1 T4. Of this total of twenty thousand cores, five each deliver z. B. 1 T 1, 2T1, 3T1, 4T1 and 5T1, the same evaluation result, in this case the number 1.

In this embodiment, too, are based on the 5 shows the individual groups of hundreds and thousands assigned to one another in such a way that that in no loop are the hundreds and thousands cores in the same row, z. B. H 1 and 1 T 1 or 1T3, become magnetically effective at the same time, so in none Line a direct loop coupling between the respective hundreds and thousands core the same line. For example, the loops are the one in the first Row lying thousands cores 1 T 1 or 1 T 3 by those in the third or fourth Hundreds cores H3 or H4 lying in the row and not through H1 or H2. It In this way, only one thousand core supplies an evaluation result in each line, on the other hand, never both cores, e.g. B. 1 T 1 and 1 T3, at the same time, because the critical Coupling points on the hundred core H3 or H4 when checking line 1 are omitted.

Is z. If, for example, loop 2311 is active and line 1 is checked, the thousand cores 1 T 1 and 1 T 3 are as good as free from interference, as the maximum of twenty loops through cores 1T1 or 1T3, H3 and H4 as well as Z1 and E1 induced interference voltage of the active cores Z 1 and E 1 is negligibly small. For the same reason, the test receiver in column H cannot respond to core H 1 either. Only the cores Z 1 and EI are identified.

When checking the second line, the test receiver in column Ta responds to core 1T2, while those in the other columns have no effect. The interference voltage possibly induced in the cores Z1 and E2 via the loops through the cores 1 T 2, H 3 or H 4, Z 2, E 2 is again negligible, as is the interference voltage in the cores 1 T4 and H2, which is likewise via Loops through the cores Z2 and E2 can be coupled with loops through the core 1T2.

When checking the third line, the core H3 is identified. the The interference voltage influence of the cores Z3 and E3 is low, as is that of the cores 2 T 1 and 2 T 3 via the loops through the cores H 5 or H6 and Z3. So is the participant 2311 clearly identified.

Summarizing the kernels of a decade in groups and line by line staggered arrangement of these groups in the next decade repeated in several consecutive decades. It is crucial that depending on the permissible signal-to-noise ratio from a certain decade upwards in each identification loop only one of those in a row Cores becomes magnetically effective.

Claims (7)

PATENT CLAIMS: 1. Method for improving the crosstalk attenuation and the signal-to-noise ratio in toroidal core evaluation fields, in which the individual cores are arranged in rows and columns and continuously closed evaluation loops are passed through the subscriber line through a number of cores corresponding to the number of digits of the subscriber number and in which the to the core combinations belonging to the individual evaluation loops are excited one after the other, for telecommunications, in particular telephone systems, characterized in that each individual toroidal core associated switching means (PW 1 to PW 0 or VW to VW 0) in the idle state the transformer properties of the cores, z. B. by pre-excitation or short circuit of a core test winding, cancel. 2. The method according to claim 1, characterized in that the switching means assigned to the individual toroidal cores of the evaluation field are influenced by contacts (sk 1 to sk 0) of the switching means (SK) controlling the connection of a test receiver (PV). 3. Procedure according to claim 1 and 2, characterized in that to determine a marked Core (e.g. H2), all cores are individually tested one after the other (pure series testing). 4. The method according to claim 1 and 2, characterized in that to determine a marked core (e.g. H2) the cores of a column or a part of a column at the same time and the individual columns are checked one after the other (column parallel check). 5. The method according to claim 1 and 2, characterized in that to determine the Cores marked the cores of a line at the same time and the individual lines in time checked one after the other (parallel line check). 6. The method according to claim 5, characterized in that depending on the permissible signal-to-noise ratio of a certain decade (z. B. H) on upwards several cores (z. B. 1 T 1, 2 T 1, 3 T 1, 4 T 1, 5 T 1) of a following decade (e.g. T) deliver the same evaluation result (e.g. number 1), the individual cores (e.g. 1 T 1, 1 T 2 or H 1, H 2) within these decades are summarized in groups (e.g. 1 T 1, 1T2 or H1, H2) and the individual groups are offset from one another line by line from decade (e.g. H) to decade (e.g. T) are checked in such a way that in all evaluation loops only a single core (e.g. 1 T 2 or H 1) common to the individual loops (e.g. 2111) from the specific decade (e.g. H) onwards becomes magnetically effective at every test step. 7. An arrangement for carrying out the method according to claim 6, characterized in that each of the cores (e.g. 1 T 1, 2 T 1 to 5 T 1) delivering the same evaluation result (e.g. number 1) for a decade ( e.g. T) a group (e.g. H 3 and H 4 or H 5 and H 6 etc.) of the nuclei combined in groups (e.g. H1 to HO) of the one lower and / or higher Decade (z. B. H) is assigned and that the individual groups from decade (z. B. H) to decade (z. B. T) are arranged offset from one another in lines. B. Arrangement according to claim 7, characterized in that the groups are formed in the individual decades of one or more cores. 9. Arrangement according to claim 7, characterized in that the cores of a decade are arranged in one or more columns.