DE1228680B - Time division multiplex system - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

H04j

German KL: 21 a4 - 49

Number: 1228 680

File number: C 28787IX d / 21 a4

Filing date: December 28, 1962

Opening day: November 17, 1966

The invention relates to a time division multiplex system for the transmission of main and auxiliary information, in particular a time division multiplex telephone system, in which the pulse frame η comprises main channels and a synchronization channel of equal duration for auxiliary information which is transmitted at the rhythm of the sampling frequency F in the cycle given by the pulse frame will.

In the case of time division multiplex systems, e.g. for telephony, it is customary to use the call signal representing an auxiliary signal for a specific voice channel in the to transmit the same channel. There are often mutual disturbances between the message and the ringing signal. This type of transmission of the auxiliary signals within the main channels they face are assigned, requires their sampling with a sampling frequency that is equal to the sampling frequency of the Voice signals of the main channels is. This causes these signals to have an unnecessarily large redundancy because the information content of the auxiliary signals is usually considerably less than that of the main signals.

The invention is based on the object for a time division multiplex system of the type described in the introduction to specify a further solution that avoids the disadvantages described.

This object is achieved according to the invention in that the synchronization channel is provided for the transmission of both the synchronization signal for the η main channels (primary synchronization signal) and an auxiliary signal sequence representing a second time division multiplex system, which is intended for the transmission of a maximum of (p + 1) q - Auxiliary information representing auxiliary channels and an associated synchronization signal (secondary synchronization signal) is formed in that a cycle of the second time division multiplex system (p . + 1) comprises cycles of the first time division multiplex system formed by the η main channels and in the synchronization channel one of the (p + 1) Cycles of the first time division multiplex system the secondary synchronization signal and (q - 1) auxiliary information and in the remaining ρ main cycles of the first time pulse system q auxiliary information are transmitted with a sampling frequency F / (p + 1).

By using the synchronization channel according to the invention for the additional transmission of Auxiliary information in addition to the actual synchronization signal results in relatively simple relationships for the technical complexity of such a system, with optimal utilization of the for Available time band.

It is already known the individual voice time division multiplex system

Applicant:

Compagnie Generale de Telegraphie Sans FiI,
Paris

Representative:

Dipl.-Ing. M. Schlenk, patent attorney,

Munich 27, Beblostr. 5

Named as inventor:
Jacques Deregnaucourt, Paris

Claimed priority:
France of December 29, 1961 (883 415)

channels in a time division multiplex system for the transmission of telegraphy in several subchannels to subdivide again. However, contrary to the present invention, the subchannels become less economical here In spite of their low information content, in the rhythm of the sampling frequency of the voice channels queried. In addition, a sub-channel of each voice channel must be used for the transmission of a additional synchronization characters are kept free.

In a preferred embodiment according to the invention, the duration of an auxiliary channel as well as the duration of the channel provided for the transmission of the secondary synchronization signal is equal to the duration T = 1 / F · (n + 1 ) multiplied by the factor l / (q + 1) ) of a main channel selected.

The invention is described below with reference to the exemplary embodiments shown in the drawing will be explained in more detail. In the drawing means

F i g. 1 shows a sequence of diagrams explaining the principle of the invention,

F i g. 2 a transmitting device according to the invention,

F i g. 3 a receiving device according to the invention,

-F i g. 4 shows the mode of operation of the transmitter and the receiver according to FIGS. 2 and 3 explanatory Diagram.

The F i g. 1a shows a time diagram for η channels V of a time division multiplex system, for example for telephony, in which a time interval T is provided for each of the channels V numbered from 1 to η. Each sample of those sampled at frequency F.

609 727/165

3 4

Information of a channel can either apply in the same way to the auxiliary channels, i.e. U = T '/ q - T /

Amplitude, duration or phase modulated (q + 1), whereby a substantial difference

or as a simplification of the circles consisting of several impulses.

Code characters are transmitted. As an exemplary embodiment, a transmitter and a

multiplex system requires an additional channel S 5 receiver for a time division multiplex system according to the

for the transmission of a synchronization pulse train, the invention with η voice channels Vl, Vl ... Vn loading

identifying the various channels as well as being written. For the language

the in-phase control of the transmit and signals positive phase-modulated pulses and for

Channel switches on the receiving side are used. For technical reasons, the primary synchronization pulse train is negative

For reasons, the channel S is given the same duration as the io pulse used.

Main channels. The width of the synchronization pulses In this embodiment, the auxiliary

However, it is only chosen as large as that for the channels Al ... Ap for the transmission of the call signals

Synchronization is required. Usually, the sampling frequency is sufficient for the main channels Fl ... Vn

a time interval s of duration UF / (n + 1) is provided for the transmission, ie ρ - η, q = 1.

from, which is much smaller than the time interval T 15 The ringing signals in the channels Al ... Aη are

(for example U = T / 5) is selected. The remaining by the presence (call) or absence (no call)

Remaining time of this channel, that of the time interval A of positive pulses xl, xl ... xn with a distance

of duration T '= T - U , remains for the excess of T / 2 with regard to the primary synchronization

unused. impulses / in the synchronization channels Sl ₁ S2 ... Sn

In the system according to the invention, the ao are transmitted while the secondary synchronizing

Time intervals A for the transmission of auxiliary information pulses J assigned to the auxiliary channels in

functions, for example ringing signals, exploited with the shape of negative pulses with a spacing of

a much lower sampling frequency than the T / 2 in terms of the primary sync pulses

Main channels get by. be transmitted in the SO channel.

A first cycle, a signal cycle, is carried out before the interval between two pulses is and should be

seen that from the synchronization channel S and also in the following always the time interval

n channels V1, V2 ... Vn . that will stand from the beginning of these two

A second cycle (Fig. Ib), which is limited by ρ + 1 pulses. It should also apply that two

first cycles and in the for the synchronous pulses (same or different duration) with

ization provided channels occurs is with SO, 30 are synchronous with each other if they are none of each other

Sl ... Sp . ^G distance, ie if their front edges are timed

To make the further explanations more concrete coincide.

To be able to, is assumed, for example (Fig. Ic), In Fig. 4 the transmitted pulses are im that the information of the main channels are positive channel S for the case of a call for the channel V1 pulses and that the synchronizing pulses for 35 are reproduced. The pulses / and / are constantly the first cycle negative pulses / that are transmitted in the same way during
of the time interval of duration U are transmitted The F i g. 2 shows the transmitting device. It assigns and primary synchronization pulses are to be called a pulse generator 1 with a repetition frequency. Furthermore, in the sections ^ of the channel SO 2 {n - \ - l) F , the period of T / 2 with T is a sequence of negative synchronizing pulses / over 40 = IjF (n + 1) the duration of a main channel , which are called secondary synchronizing pulses. The generator 1 is to be output with a bi. The intervals connected in the synchronizing-stable flip-flop 2, whose out-channels SO, Sl, Sl ... Sp with the duration T (Fig. Ib) gears 23 and 24 square pulse trains of the period T are analogous to AO, Al, Al . .. called Ap . feed two equal circuits 25 and 26 out of phase »

The time intervals A 1, Al ... Ap can therefore each have a differentiator and an equal *

are occupied according to ρ auxiliary channels, whose Richter contains and acts in such a way that at the output of 25>

The synchronization channel is formed by the time interval AO that is connected to the control circuits, short pulses

and which occur for the transmission of auxiliary information with the frequency F (n + 1), the pulses

the sampling frequency F / (jp + 1) can be used. correspond to the odd order of generator 1,

In the same way, it is possible to set each time interval 50 and at the output of 26, which is associated with the call circles.

AO, Al ... Ap is bound in q equal sections of duration, pulses of the same duration and the

T '/ q subdivide that allow (p + 1) · q - 1 same frequency to occur, making the pulses straighter

Auxiliary information and the secondary synchronization order of generator 1 correspond,

signal to transmit, this in the first section The control circuits have a known technology

of the time interval AO of the synchronization channel SO un- 55 channel pulse distributor 4, whose input with the

is accommodated. Output of the circuit 25 is connected and its

This split is important if (n -f- 1) outputs 4-1, 4-2 ... 4-n and 4-s are fed according to a number of η relatively emphasized auxiliaries. The η first outputs 4-z information transmitted and in a simple manner (i = 1, 2 ... ") are channel outputs which is to be enter known (for example, by pre- 60 speaking modulators 5-i with positive pulses handensein or The absence of a positive repetition frequency F , of which every other pulse in the channel), without having to increase the modulation magnitude ρ significantly via an input 6-z and without what the consequence of this receives voltage of the voice channel Vi,
would be the sampling frequency F / (p + 1) of the auxiliary channels. In the figure, only the circuit parts i = 1 need to be unduly reduced. 65 and i = η . For the other parts of the circuit

In this case there is also an interest in the corresponding applies.

the transmission of the primary synchronization pulses, the pulses of frequency F at the output 4-j mar-

to equalize the sections s of the channels S. This marks the beginning of the synchronization channels. they are

5 6

a generator? at which each active impulse (present or not present)

The impulse to hit synchronously feeds a negative primary of the auxiliary call channels A i . This separation can

Synchronizing pulse triggers. can be carried out by conventional means. this

The circuit includes the pulse distributor 4, which is particularly the case when the synchronizing

Modulators 5- / and the generator 7 and works 5 pulses / and / negative and the remaining pulses

as in a conventional time division multiplex system. are positive. The polarity can then be used for the separation

Here, however, the output 4-j is still used with which the impulses are used as a criterion,

second input of a bistable flip-flop 8 with the output 32 is connected to the input of a one

two inputs and one output, the input and one output having mono-

First input connected to the output of the circuit 26 io stable flip-flop 34, which is in the

communicates. Working position has the duration T. Everyone at the entrance

Every pulse that occurs at the trigger circuit via output 4-s controls the trigger circuit in its

incoming impulse (these impulses are uneven working position around, provided they are previously in the rest position

Impulses that originate from circle 25) prepares the findings. Otherwise nothing happens. If the

Toggle circuit 8 in such a way that it tips over, 15 toggle circuit tips over in its working position, it can

if it comes from the exit of the circle 26 - only after the time T back to its rest position -

The even-order impulse follows. Tilt it so that a pulse / at the input is only effective

according to the flip-flop 8 so long can not be opened when the previous pulse

the sequence of even pulses until it again has a distance greater than T. The impulses / that

is unlocked. It therefore delivers a 20 via its output at a distance of T / 2 to the preceding one

Square-wave signal with frequency F that follows circle 9, impulses /, can therefore not have an effect

the one made up of a differentiator and an equal.

There is light, is used to the sequence. For this reason, the flip-flop 34 delivers a

straight pulses of frequency F, which are the toggle square wave signal with frequency F, its vertical

circuit 8 has operated to regain. The edges coincide with those of the impulses /. This

The pulses at the output of circuit 9 are fed to the signal is fed to a circuit 35, which has a differential

The output of Rufimpulsverteilers 10 supplied, the decorative element and contains a rectifier, with their

Has η + 1 outputs, of which the η first aid he made the original from this square-wave signal

Channel outputs 10- / and the synchronization output Pulses / restores.

10-0 successively with the pulse train of frequency 30 The output of circuit 35 is connected to the first input

F / (n + 1) are fed. The η first outputs gang of a locking gate 36 connected, at the two-

10- / feed the first inputs of the current gates H- /, tem input which are supplied by the isolating stage 31 via the output

whose second inputs are 12-z and modulators of the pulses / and J supplied to output 32 are present. At the end »

Auxiliary channels A i represent, which with regard to the ringing of circuit 36 thus only the pulses / occur.

signals for the voice channels Vi for transmission 35 The pulses / with the repetition frequency F at the output

to be needed. of the circle 35 are also used to synchronize the

A certain circle H- /, for example 11-2, is used pulse generator 37, the pulses of the sequence *

unlocked only when a frequency 2 (n + 1) F is generated at its input 12-2.

Voltage is applied, their presence or their The output of generator 37 is connected to the one-size gear, the presence of a call for the voice 40. 38 indicates a two outputs having bistable channel Vl. The circles H- / act like Modu- flip-flops 39 connected, which with each of the on lators, at the outputs of which appear at their first input to their input 38, from the generator 37 present impulses either unchanged touching pulses, in such a way that on their out or not occur at all. 41 and 42 square rectangles in phase opposition to each other *

The output for the synchronization 10-0 of the ver 45 signals of the frequency F (n + 1) occur. The distributor 10 is also supplied with the frequency F / (n +1) gears 41 and 42 are connected to two circuits 43 and 44 verden generator 13 for the secondary synchronizing, each of which has a differentiator and pulses, each at the input of the generator 13 has a rectifier. They are used for the pulse that occurs synchronously, a negative second of two sequences of short pulses of frequency F which triggers the synchronization pulse / which then occurs in 30 (n + 1), which occur at their outputs and occurs against · channel A 0. offset each other by T / 2 (period of generator 37)

Which are pushed at the outputs of the η modulators 5- /. The flip-flop 39 has a syn-

occurring modulated control signals from the chronizing input. To make sure that the

Generator 7 supplied primary synchronization signals /, phase position of the signals at the outputs 41 and 42,

the 55 routed through the gate circuits H- /, among other things, also the pulse train at the output of the

Call signals and the circuit 43 supplied by the generator 13 is correct, the synchronizing pulses /,

Synchronization signals / are in the mixer 14 in one which are supplied by the circuit 35 and already to the syn-

other nested and the transmission device of the generator 37 are used, too

services supplied. another input 40 of the flip-flop 39 is supplied.

The F i g. 3 shows schematically the transmission 60 This input 40 is the synchronization input.
device according to FIG. 2 associated reception At the exit of the circle 43 finally come to the device. The incoming impulses are in the impulses / synchronous impulses as well as in the usual manner with a classic receiver shear impulses which are received with respect to the impulses / and fed to a separating stage 31 which are offset by an integer times T. These two signals, the negative primary and 65 primary pulses, represent the reference pulses required for the demodulation of the secondary synchronization pulses / and J and their speech channels with voice channels Vi including the modulated positive an odd number times T / 2 against the impulses / ver

are set, which also include the synchronization pulses /.

The output of circuit 43 feeds a pulse distributor 45 with (n + 1) outputs, of which η outputs 45-z "are the channel outputs and output 45-5 is the synchronization output, to which the input-side pulses are fed one after the other Pulse distributor via its input 46 from the output of the circuit 35 pulses /, which synchronize it in such a way that the pulses synchronous to the pulses / pulses at the output of the circuit 43 at the synchronization output 45-s and the following pulses according to their order at the channel outputs 45-1, 45-2 ... 45-n occur.

Each output 45-z 'is connected to an associated demodulator 47-z, ie a demodulator for the voice channel Vi, which on the other hand receives the modulated control pulses and the ringing pulses via a second input connected to the output 33 of the isolating stage 31 and under the influence of the reference pulses supplied via the output 45-z 'of the distributor 45, it is controlled in such a way that it processes only the modulated control signals associated with its voice channel. These demodulators work in the usual way, their reference pulses not only eliminating the foreign voice signals, but also those of those call channels which must not result in any change in the circuits. The output signals of the demodulators 47-z are processed further in the usual way.

The pulses at the output of the circuit 44 represent, as already said, a pulse train with the repetition frequency F (n + 1) and contain, among other things, the synchronization pulses /, which have a distance T / 2 with respect to the preceding pulses /. These pulses are fed to the first input of a bistable flip-flop 48 with two inputs and one output, of which the second input receives the synchronization pulses / frequency F supplied by the synchronization output 45-s of the distributor 45.: The flip-flop 48 toggles at each of the output 45 -s supplied pulse, while only those of the pulses supplied by the circuit 44 trigger a tilting process which immediately follow a preceding pulse supplied by the output 45-i. In other words, the flip-flop 48 delivers a square-wave signal of frequency F, which is fed to a circuit 49 containing a differentiating element and a rectifier, which in turn derives pulses at the repetition frequency F which, with regard to the pulses /, have a distance T / 2 and to the pulses / represent synchronous impulses as well as synchronous, possible ringing impulses forming intermediate impulses. These pulses are fed to the input of the pulse distributor 50, which has (n -j- I) outputs, a synchronization output 50-0 and η channel outputs 50-z. The distributor 50 is synchronized by the pulses / supplied by the blocking gate 36 in such a way that at its output 50-0 the pulses synchronized with the pulses / of the repetition frequency FJ (n + 1) occur at the same time as the pulses supplied by the circuit 49, while the other outputs 50-z sequentially in the correct order of i =; 1 to i = η are fed with pulses of the same repetition frequency F / (n + 1).

The output 50-0 is not needed, while the η outputs 50-z 'feed associated first inputs of coincidence circuits 51-z, the second inputs of which receive the control and call signals from the output 33 of the isolating stage 31. Each coincidence circuit 51- / supplies via its output only the possibly occurring call signal associated with its voice channel Vi , to which the auxiliary channel A i is assigned.

These signals are processed further in the manner customary in time division multiplex systems.

As a numerical example, the case η = 7, F - 8 kHz can be considered, which leads to an extremely favorable sampling frequency for the ringing signals.

For a time division multiplex system with a large number of channels, as already indicated above, it is necessary to provide q auxiliary channels in the channels for the primary synchronization, each of which has a duration T / (q + 1).

Assuming that a secondary cycle comprises (p + 1) primary cycles, there are q (p + 1) -1 auxiliary channels, some of which may not be used. If the auxiliary information is call signals for the η voice channels, then it is sufficient if q (p + 1) -1 S> η . If q is given, then the smallest number for p that still fulfills this condition results from the relation q (p + 1) <^ η + q. With regard to the case q = 1, this means an increase in the sampling frequency. The adaptation of the circles described to the case in which ρ differs from η and q > 1 is to be carried out analogously. If the type of transmission device described above is assumed, a generator with the frequency (q + 1) (n + 1) F must be used in place of the generator 1 required on the transmission side.

Via a channel pulse distributor, which operates as described above, a pulse train {q + 1) and the groups of q other pulse trains, the repetition rate of which is F · {n + 1), passed through a device which allows only the To receive groups of pulses assigned to channels S , the group frequency of which is F. The device is in this case synchronized by the synchronization output of the channel pulse distributor which supplies pulses at the frequency F. These groups feed a call distributor, which this time has (p + 1) q outputs, of which one synchronization output feeds the generator for the secondary synchronization pulses, and the other outputs representing channel outputs feed (p + 1) 1 - 1 coincidence circuits accordingly that have the modulators for the auxiliary call channels. It can be seen from this that if (p + 1) q − 1 is greater than the number of auxiliary information items to be transmitted, some of these outputs can remain unused.

It is assumed that the synchronizing pulses / and / are separated from the control and ringing pulses as described. The pulses / and / are then separated from one another, as also described, by means of at least one device having a monostable multivibrator, the dwell time of which in the working position is determined by the intervals between the pulses / and /; it can therefore also be T.

The generator 37 on the receiving side is replaced by a generator with the frequency (q + 1) (n + 1) F , analogously to the generator 1 on the transmitting side. One of the pulses / synchronized device makes it possible to derive from this generator on the one hand a first pulse train of the repetition frequency F (n + 1) and on the other hand a second pulse train, of which the first pulse train with the impulses / synchronous pulses and intermediate pulses has the Demo-

dulators of the speech channels serve as reference pulses, and of which the second pulse train is formed by the groups of q pulses with the group frequency F (n + X) .

The first sequence is fed via a distributor with (n + X) outputs for pulse trains with the frequency F , of which η outputs, which form the channel outputs, feed the demodulators of the speech channels and of which the (n + l) -th output The synchronization output is only used to maintain the groups of q pulse trains in the second pulse train that are present in the S synchronization channels.

The pulse train transformed in this way is passed through the ringing pulse distributor, which in turn is synchronized by the pulses /. Each distributor feeds (p + 1) q - 1 coincidence circuits which have the demodulators for the auxiliary channels.

Finally, it should be noted that ρ can theoretically be made equal to zero, which means that the ao channel for the secondary synchronization is omitted and only a single piece of auxiliary information has to be transmitted. However, this case is generally of little importance.

Claims (8)

Patent claims: X. Time division multiplex system for the transmission of main and Hih ° s information, in particular time division multiplex telephone system, in which the pulse frame η comprises main channels and a synchronization channel of the same duration for auxiliary information, which are transmitted in the rhythm of the sampling frequency F in the cycle given by the pulse frame, thereby characterized in that the synchronization channel (S) is provided for the transmission of both the synchronization signal for the η main channels (primary synchronization signal) and an auxiliary signal sequence representing a second time division multiplex system, which is intended for the transmission of a maximum of (p + 1) q - 1 auxiliary information representing auxiliary channels and a synchronizing signal associated with them (secondary synchronizing signal) is formed in that a cycle of the second time division multiplex system (p + 1) comprises cycles of the first time division multiplex system formed by the η main channels and in the synchronizing channel (S) one of the (p +1) cycles of the first time multiple xsystems the secondary synchronization signal and (q - 1) auxiliary information and in the remaining ρ main cycles of the first time division multiplex system q auxiliary information is transmitted with a sampling frequency F / (p + X). 2. Time division multiplex system according to claim 1, characterized in that the duration of a hoof channel as well as the duration of the channel provided for the transmission of the secondary synchronization signal is equal to the duration T = XIF · (n + 1 ) multiplied by the factor l / (q + 1) ) of a main channel. 3. Time division multiplex system according to one of the preceding claims, characterized by a Multi-channel system for speech, the auxiliary information of which is ringing. 4. Time division multiplex system according to one of the preceding claims, characterized in that the transmitter has the following facilities: a) a pulse generator with the repetition frequency ( b) a device which derives from this basic pulse train a first pulse train with the repetition frequency (n + 1) F and a second pulse train with groups consisting of q pulses of the group frequency («. + 1) f; c) a first pulse distributor fed by the above-mentioned first pulse train, which in turn supplies the pulses one after the other (n + 1) outputs, of which the first m outputs with the sampling frequency f the modulators belonging to the main channels and the last output with the sampling frequency F den Feed signal generator for the primary synchronizing signal; d) a device fed by the second pulse train and synchronized via the mentioned last output of said first pulse distributor, which derives a third pulse train which is composed of groups of q pulses with a group frequency F and which are inserted in certain time segments within the synchronization channels; e) a second pulse distributor fed by the third pulse train mentioned, which has q (p + 1) outputs, at each of which there is a pulse train with the frequency F ₁ Kp + 1) and of which the q (p + 1) - 1 the first outputs feed the modulators of the auxiliary channels and the last output triggers the pulse generator for the secondary synchronization; f) a mixer that generates the output signals of the generators for the primary and the secondary Synchronization signal as well as the output signals of the modulators for the main and auxiliary channels. 5. Time division multiplex system according to one of the preceding claims, characterized in that the recipient has the facilities listed below: a) a detector stage, which is followed on the output side by a separation stage, which has a first Output for the primary and secondary synchronization signal and a second output for the modulated signals of the main and auxiliary channels; b) a device fed by the first output of the aforementioned separation stage, which alternately on the one hand the primary synchronization signal and on the other hand the secondary synchronization signal supplies; c) a pulse generator at frequency (q + 1) (n + 1) F, which is synchronized by the primary synchronizing signal; d) a device which is fed by said pulse generator and is synchronized by the primary synchronization signal and on the one hand supplies a first pulse train with the frequency (n + 1) F and on the other hand a second pulse train, the first pulse train the synchronization pulses of the primary synchronization signal and intermediate pulses and the second pulse train from the composed of q pulses 609 727/163 There are groups with the group frequency (n + 1) F , which contain those that are provided in the time intervals kept ready within the synchronization channels, as well as the groups of intermediate pulses; e) a first pulse distributor fed by said first pulse train and synchronized by said primary synchronization signal, which via its synchronization output supplies a first pulse train synchronous to the primary synchronization ίο nization and also feeds the other η outputs with pulses of the repetition frequency F , which in turn with the demodulators for the main channels, which are on the other hand connected in parallel to the second output of the isolating stage, in connection; f) a further device, which is fed by said second pulse train and synchronized via the synchronization output of said first pulse distributor, which supplies a third pulse train which is composed of the individual groups present within the time intervals of the synchronization channels and whose group frequency is consequently F ; g) finally a second pulse distributor, which is generated from said third pulse train feeds and is synchronized by the secondary synchronization signal and has q (p + 1) - 1 outputs at which pulse trains with the frequency F / (jp + 1) occur and those with the demodulators for the auxiliary channels, which are on the other hand parallel to the second output of the mentioned separation stage are switched on, are in connection. 6. Time division multiplex system according to one of the preceding claims, characterized in that the signals of the main channels and the signals of the auxiliary channels in the form of positive modulated pulses and transmit the primary and secondary sync signals in the form of negative pulses are. 7. Time division multiplex system according to claim 5 or 6, characterized in that the positive modulated Pulses of the auxiliary channels are modulated by their presence or absence. 8. Time division multiplex system according to one of the preceding claims, characterized in that the modulators for the auxiliary channels from the gate circuit and the associated demodulators Coincidence gates exist. Considered publications:
German Auslegeschriften No. 1 056 676.1 059 983. 1 sheet of drawings 609 727/165 11.66 © Bundesdruckerei Berlin