DE1916677A1 - Telephone exchange with time division multiple switching through pulse amplitude modulated voice information - Google Patents

Description

Dipl.Phys.Leo Thul λ n't conn

Patent attorney lid IOD //

7 Stuttgart-Feuerbach
Short Street 8. ■ ·

G.Gara-4

INTERNATIONAL STANDARD ELECTRIC CORPORATION, NEW YORK

Telephone switching system with time-division switching through pulse-amplitude-modulated voice information

The invention relates to a telephone exchange with time-division switching through of pulse-amplitude-modulated voice information.

The object of the invention is a method for signaling and / or for monitoring in the channels.

The telephone exchange according to the invention is characterized in that of the period for the Durchschaltmg one Channel is split off a period of time for monitoring the state of the multiple line, and that only the remaining active channel time for evaluating the transmitted voice information is used.

A special embodiment of the telephone exchange according to the invention is characterized in that a first electronic Switch is connected to the multiple line, which is only open during the period provided for monitoring is that this first electronic switch feeds a monitoring circuit so that the latter is free or occupied of a certain time channel, and that at least the speech path switch closest to the first electronic switch is blocked during the monitoring period of the channel.

A further development of the inventive concept is characterized in that that apart from the period for monitoring and apart from the period for evaluating the transmitted voice information

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a period of time is provided for signaling in which the first The switch is also open and the said speech path switch rl is also closed, and that the electronic switch has two outputs, one during the monitoring time and the other is open during signaling time.

An embodiment of the circuit arrangement according to the invention is explained below in connection with the drawing, which is the essential part of an understanding of the invention Time manifold shows.

A telephone exchange is required in which the subscribers are assigned fixed time slots in a multiple cycle. In such a system, a connection is established in which each of the participants involved is connected to a so-called audio line via several speech path switches. This listening line is used to convert the modulated impulses from the time slot of one participant into the time slot of the other participant.

The exchange works with a basic clock rate of 256 kHz, the duration of a channel time slot is therefore 3.9 / US. This period includes 3.1 / Us active channel time that is within the pulse time is embedded so that the period between two active Channel times is 0.8 / US, in which the multiple line discharges can be. This is to prevent crosstalk between adjacent channels. The impulses controlling the discharge have a duration of 0,4vus and are between ^ ieils two active channel times centered. Therefore, the beginning and end of the discharge pulses are separated by 0.2 / US from the active channel time. The discharge pulses are labeled BS 5. The spaces in between between consecutive active channel times are through

J) Q 0.8 / us long gap pulses BS 4 determined. A voice evaluation pulse BS 6 is 1.5 / US long, it begins 1.4 / US after the start of the active channel time and listens to 0.2 / US. the end of the active channel time. A pulse BS 7 is 0.4 / Us long and coincides with the first

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0.4 yus of the active channel time. A pulse BS 8 is also 0.4 yus long and begins 0.5 Ms after the start of the active channel time. The pulses BS 7, BS 8 and BS 6 appear in this order without mutual overlap in each channel period. - ·

The accompanying drawing shows parts of a time division line
with two speech path switches VT 1 and VT 3 · These are also called
Crosspoint switch denotes that each is located at an intersection between two multiple lines in a coordinate-shaped matrix of such multiple lines. These crosspoint switches are controlled by a crosspoint spearer, the
stores the time slots in which this crosspoint is used.

During the active channel time of a used time slot, the Cross-point spreader conducts the corresponding cross-point switch.

In the case of the speech path switch VT 1, this is effected by the gate circuit G3, the input XS of which is excited for this purpose. This gate circuit is activated in the gap pulse time by the pulses
BS 4 blocked. At the same time, the gate circuit G5 opens the switch VT 3. These two switches VT 1, VT 3 are capacitively coupled.

pelt, as it is in our registration, which is running at the same time

P (G.Gara, et al 3-2-2-1). The basistor circuit G5 of the switch VT 3 is during the duration of the impulses BS4, BS7 and BS8 blocked via gate circuit G6.

The discharge of the multiple line is effected via a further transistor VT 6, the base of which is controlled with the above-mentioned discharge pulses BS $. The audible tones and characters are fed to the multiple line at the appropriate times via the Beö.s of a transistor VT7. This is intended by the reference symbol TS
are indicated at the base of the transistor VT7.

Now consider signaling and monitoring. Of the Emitter of a transistor VT5 is connected to the multiple line and its collector output feeds two gate circuits Gl and G2, for which it represents an inverter. The other entrances to this-

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The pulses BS7 or BS8 are fed to gate circuits. To the At the time of the pulses BS7 and BS8, the crosspoint switch VT 3 is not open, so the transistor is activated at this time VT5 a current flow to the multiple line, whereby the transistor VT5 becomes saturated. The fact; that the collector potential of the transistor VT5 is then low, unlocks the gate circuits Eq and G2, so that both emit an output signal. These output signals indicate the presence of a current on the multiple line and represent the character output. Am At the end of the pulse BS8, the transistor VT ^ is opened, so that the transistor VT5 is blocked and the current spill over the transistor VTJ flows.

It should be noted that the gate circuit Gj5 only during the pulse BS4 is blocked. If a test were also necessary with regard to the transistor VTl, then this gate circuit would be in de'r controlled in the same way as the gate circuit G5 * which controls the switch VT3 controls.

The circuit of the transistors VT2 and VT4 is only hinted at they are allowed as fixed points for the base of the crosspoint transistors.

6 claims,
left zelchn., left fig.

9098U / 123-5

Claims (6)

G. Gara-4 ". Claims Telephone exchange with time-double switching of pulse-amplitude-modulated voice information, characterized in that a period for monitoring the state of the multiple line is split off from the period for switching a channel through, and that only the remaining active channel time is used to evaluate the transmitted voice information. 2. Telephone switching system according to claim 1, characterized in that a first electronic switch (VT5) is connected to the multiple line, which is only open during the period provided for monitoring, that this first electronic switch (VT5) has a monitoring circuit (Eq. G2) feeds so that the latter can recognize the free and occupied status of a certain time channel, and that at least the speech path switch (VT5) closest to the first electronic switch (VT5) is blocked during the monitoring period of the channel. j5. Telephone switching system according to Claim 2, characterized in that, in addition to the period for monitoring and apart from the period for evaluating the transmitted voice information, a period for signaling is provided in which the first switch (VT5) is also open and the said speech path switch (W5) is also closed , and that the electronic switch (VT5) has two outputs, one of which is open during the monitoring time and the other during the signaling time. 4. Telephone switching system according to claim 3, characterized in that the speech path switch consists of base-controlled transistors (VTl, VT3), the emitter-collector path of which is in the multiple line, V- 9Q98A4 / 1235 ta · ·> lilt II ι G.Gara-4 fr 1 916677 5. Telephone exchange according to claim 4, characterized in that the first electronic switch (VT5) is a tram-stor whose emitter is connected to the multiple line. 6. Pernsprechvermittlungsan] gge according to claim 2 or claim, characterized in that the monitoring period or the signaling period occur at the beginning or in the vicinity of the beginning of a channel time slot.