BG43Y1 - System for message transmission - Google Patents

Abstract

The system ensures simultaneous connection of several subscribers to an automatic telephone exchange using one standard subscribers's telephone line. For every subscriber on the subscriber's side the following are designed, connected in series: two-way analogue-digital converter (2) and compressor/decompressor unit (3), and on the side of the automatic telephone exchange a two-way decompressor/compressor unit (3') and switchgear (1)) are designed, connected in series, across the digital-analogie converter (2), or across control circuits, respectively. All compressor/decompressor units (3, 3') are interconnected across the sole subscribers' telephone line (6) by means of a multiplexor/demultiplexor (4, 4'), designed on both sides. The latter are connected to a modem (5, 5') each for the modulation and demodulation of the simultaneously transmitted signals across the line (6).

Description

TECHNICAL NATURE OF THE USEFUL MODEL

This objective is achieved by a message system comprising a line for connecting subscribers to an automatic telephone exchange, at the two ends of which is connected a modem block for modulating and demodulating the data in accordance with the intended transmission.

Each modem block is connected to its respective multiplexer / demultiplexer. The subscribers are connected to bidirectional analog-to-digital converters connected to one multiplexer / demultiplexer, and the switchboard of the automatic telephone exchange is connected to control circuits connected to the other multiplexer / demultiplexer. The connection between bidirectional analog-to-digital converters and one multiplexer / demultiplexer, and between the control circuits and the other multiplexer / demultiplexer is made by a corresponding compressor / decompressor unit.

The objective is also achieved through a messaging system including a line for connecting subscribers to an automatic telephone exchange, at the two ends of which is connected a modem block for modulating and demodulating the data in accordance with the intended transmission. Each modem block is connected to its respective multiplexer / demultiplexer. The subscribers are connected to bidirectional analog-to-digital converters connected to one multiplexer / demultiplexer and the switchboard of the automatic telephone exchange is connected to control circuits connected to the other multiplexer / demultiplexer. The connection between the modem block and the multiplexer / demultiplexer is via a compressor / decompressor block.

These means make it possible to transmit a certain number of calls or to carry out other data transmissions simultaneously on the existing line between the subscribers and the control panel, depending on the quality of the line, respectively on the whole connection.

For example, in a line with a length of 5 to 8 km and a core diameter of 0.6 mm, for example, up to four voice signals can be transmitted simultaneously without degradation. In this case, each talk channel can be replaced by three parallel fax or equivalent 9600 baud channels. In this way it is possible to transmit, for example, in addition to two calls, as well as six fax messages, or three calls and three fax messages, at the same time.

Thanks to the utility model, conditions can be provided so that the normal lengths of the lines and the cross sections of the cores are sufficient to achieve a bit error rate of better than 10 ⁶ . The distances that can be covered without signal recovery range from 2 to 10 km, depending on the quality of the line, such as the cross-section of the core from the condition of the line and the presence of deviations or short sections and sections with different cross-sections. In this case, phantom power of the subscriber circuit is possible by the automatic telephone exchange by transmitting data on the line, which do not have direct current formatting, thus the operation is possible even in case of power failure.

The bi-directional modem blocks connected to the line can modulate and demodulate the data, for example according to the CC1TT standard. In principle, however, modulation and demodulation can be performed by other standards.

According to the utility model, it is possible to carry four calls simultaneously at the usual line lengths and core diameters.

According to a variant of the utility model to the multiplexer on the subscriber side, parallel to the telephones, other devices such as computers, faxes or telexes are connected as subscribers, via additional modems, respectively through other multiplexers / demultiplexers, and from the automatic telephone exchange side to its switch via control circuits interconnects the outputs of the multiplexer / demultiplexer with the intermediate inclusion of other multiplexers / demultiplexers.

In this way, it is possible to transmit data between computers, faxes or telexies simultaneously with telephones while making calls.

The digital data transmission provided also allows for channel partitioning. It is also envisaged that in the case of an appropriate extension of the system, for example, one talk channel should be replaced by three telex, fax or modem channels, each with 9600 stitches.

According to the utility model, ordinary telephones can be connected without any changes without any changes to the existing switchgear of the automatic telephone exchanges.

In addition, when the switching devices are analog, the control devices connected to the telephones may be bidirectional analog-to-digital converters and the control devices connected to the devices are modems.

These measures make it possible to adapt the system to the existing analogue telephone system.

In addition, it may be envisaged for digital switching devices that the control devices be constructed of line-free non-analog-to-digital converters, making it easy to connect ordinary fax machines, computers or telex devices to a digital telephone system. In principle, however, it is possible to use ordinary linear cards, although existing analog-to-digital converters will not be required.

According to another embodiment of the utility model, a transformer is connected in parallel to the modem block from the ATC and from the subscriber, where symmetrically formed secondary windings of each transformer are connected to each other - each by a capacitor, and to the electrodes of the ATC connected to the transformer by the ATC. a DC source is connected and a DC / DC converter is connected to the transformer capacitor by the subscriber, the two ends of the secondary windings of the two transformers being tied together by transmission lines.

With these measures, it is possible to supply the system from the telephone exchange to the subscriber's side without having to install a battery which would cause significant problems in terms of its maintenance.

DESCRIPTION OF THE FIGURES Attached

The utility model will be further explained by means of the attached figures, of which:

Figure 1 is a block diagram of a subscriber-side messaging system;

Figure 2 is a block diagram of the respective side of an automatic telephone exchange with analog posts;

Figure 3 is a block diagram of the respective side of an automatic telephone exchange with digital posts;

Figure 4 is a block diagram of a variant of a subscriber's messaging system;

Figure 5 is a block diagram of the side of the automatic telephone exchange with analog posts in Figure 4;

Figure 6 is a block diagram of the side of an automatic telephone exchange with digital posts corresponding to Figure 4;

Figures 7 to 12 - different options for executing the location of subscribers and;

Figure 13 is a diagram for power supply to subscribers.

EXAMPLES FOR THE IMPLEMENTATION OF THE INVENTION

According to FIG. 1, the subscribers' devices 1 are connected to bidirectional analog-to-digital converters 2, which convert, on the one hand, the analog signals received from the subscriber's devices, which typically have a frequency range from 300 Hz to 3400 Hz, into digital signals, and on the other on the other hand, the digital signals coming from the transducer connected 2 bidirectional compressor / decompressor units 3 are converted into analog signals which are transmitted to the subscriber apparatus 1.

In this case, the converters 2 transmit digital signals, which are transmitted to the respective compressor / decompressor unit 3 at a transmission rate of approximately 64 kilobits / sec.

These compressor / decompressor units 3 operate in a bidirectional fashion because they compress the signals from the analog-to-digital converters 2 and decompress the digital signals from the multiplexer / demultiplexer 4 and then transmit them to the converters 2.

In this case, the two-way compressor / decompressor units 3 compact the signals received from the converters at a speed of 64 kilobits / sec at 32, 24 or 16 kilobits / sec, depending on the compression algorithm or quality requirements. The decompression is done in reverse order.

The multiplexer / demultiplexer 4 also operates bidirectionally, processing on the one hand the multiplexing signals received from subscribers into one signal, and on the other hand, in the demultiplexing mode, distributing the incoming lines 6, respectively, from the connected modem. 5, signals on the individual interconnecting lines 7. On line 6, in addition to call and transmission data, additional and switching-technical information such as selective, charge, respectively transit, impulses are transmitted.

To the two-way multiplexer / demultiplexer 4, in addition to the subscriber apparatus 1, three computers 8 are connected through the two-way multiplexer / demultiplexer 15, as well as three fax machines 9. The output of each fax machine 9 is connected by a neutralizing modem 10, which neutralizes the operation of the telephony in the operation of the telephone. devices 9 output modem. Through the bidirectional multiplexer / demultiplexer 16, these three fax machines are connected to the main multiplexer / demultiplexer 4.

In FIG. 2 and 3, a modem block 5 'is connected to line 6 to the line 6, wherein the modem blocks 5.5' create the modulation and / or demodulation necessary to transmit the multiplied and processed signals. If the system operates on the CCITT standard, then the line 6 data format may meet the standard specified by this standard on the new Digital Integrated Services Network (ISDN) U _o bus.

The modem block 5 'is connected to a bidirectional multiplexer / demultiplexer 4' which is connected to part of its output lines 7 'by bidirectional compressor / decompressor blocks 3'.

In the case of a switch having analog signal control, the compressor / decompressor units 3'is connected to bidirectional digital-to-analog converters 2 ', which in turn are connected to the switch 11 by controlling it with analog signals.

Other output lines 7 are connected according to FIG. 2 with modem blocks 12 through another connected to the data lines of the computers 8 running a bi-directional multiplexer / demultiplexer 15 ', as well as through a connected to the data lines of the fax machines 9 and a bi-directional multiplexer / demultiplexer 16' such as these modem blocks 12 are switched on before the switch lie analog signal control and convert digital signals received from line 6 into analog.

In the digital signal control switch 11 'according to FIG. 3, the compressor / decompressor units 3' are connected to subscriber circuits 13, to which digital signals are outputs. These subscriber circuits refer to digital telephone exchanges and come in the form of circuit boards that have been modified so that they no longer contain an analog-to-digital converter.

The main multiplexer / demultiplexer 4 'connected to the computers 8 is also connected to a bi-directional auxiliary multiplexer / demultiplexer 15', connected to the fax machines 9 output line 7 to another additional bi-directional multiplexer / demultiplexer 16 '. The outputs of these additional multiplexers / demultiplexers 15 'and 16' are connected directly to the subscriber circuits 13, which allows the arriving digital signals to match the requirements of the switch 11 '.

The main multiplexer / demultiplexers 4,4' alternatively can be arranged such that connected to the apparatus 8, respectively 9, additional multiplexer / demultiplexers 15 and 15 ', respectively. 16 and 16 'may be dropped and their functions taken over by the main multiplexer / demultiplexers 4 and 4'.

The embodiment of the utility model shown in FIGS. 4 to 6 differs from that shown in FIGS. 1 to 3, in that the two-way compression / decompression is central.

For this purpose, the outputs of the bidirectional analog-to-digital converters 2 are connected directly to the main multiplexer / demultiplexer 4 in the same way as the digital data outputs of the computers 8 and the outputs of the modem blocks 10 connected to the fax machines 9.

A two-way group compressor / decompressor unit 17 is connected to the main multiplexer / demultiplex sor 4, at the output of which the input of the modem block 5 is connected, wherein line 6 is again connected to the output of the modem block 5, i. is an ISDN-U interface scheme according to CCITT.

Figure 5 shows the part on the side of the automatic telephone exchange of this utility model variant, in the case of a telephone exchange with analog signal control, and figure 6 shows an automatic telephone exchange with digital signal control. In both cases, i. 5 and 6, the end of line 6 on the PBX side is connected to the modem block 5 ', i.e. to its circuit representing an ISDN-U interface that is coupled to a group bidirectional compressor / decompressor unit 17 'and the latter to a master bidirectional multiplexer / demultiplexer 18'.

The subscriber outputs of the master multiplexer / demultiplexer 18 'according to Figure 5 are connected via data lines 7' directly to bidirectional analog-to-digital converters 2 ', and the corresponding apparatus 8 and 9 outputs of the master multiplexer / demultiplexer 18' through the lines 7 ' directly to modem blocks 12.

According to FIG. 6, the lines 7 'and 7 are output directly from the main multiplexer 18' to the subscriber circuits 13 with digital signal output.

The two alternative embodiments of the system according to the utility model are mutually consistent, which is expressed by the same conventions.

For a more precise definition of the two-way principle of operation, the following summary scheme of the operational character of the individual blocks characterized by their symbol is shown.

Table 1

The blocks work as

Transferring data from Analog-to-digital converter Compressor unit Decompressor unit Multiplexer Demultiplexer Digital to Analog Converter ATC subscriber 2 3.17 3 ', 17' 4,15, 16,18 4 ', 15', 16'18; 2 ', 12 ATC to the subscriber 2 ', 12 3 ', 17' 3.17 4 ', 15' 16 ', 18', 4,15, 16,18 2

In FIG. 7 to 11 show different companions of different subscribers' building blocks.

In the layout of FIG. 7, modem unit 5 is connected to the main multiplexer / demultiplexer 4, to which several compressor / decompressor units 3 are connected, each of which is connected to an analog-to-digital converter 2. These converters 2 are connected to their outputs by interface circuits 20 to the subscriber lines to which the circuits 20 are connected to the subscriber apparatus 1.

This structure is very simple, but it has the disadvantage that relatively complex and expensive items are required.

The scheme of FIG. 8 is different from that of FIG. 7 in that a group compressor / decompressor unit 3 is connected between the modem block 5 and the main multiplexer / demultiplexer 4, the analog-to-digital converters 2 being connected to the main multiplexer / demultiplexer 4.

In this embodiment, a very good solution is obtained because with a small number of elements optimal efficiency is achieved. It is also possible for the master multiplexer / demultiplexer 4 to be arranged together with the converters 2 and the interface circuits 20 as an integral element on the chip, as shown in FIG. 9.

In the embodiment of FIG. 10, which corresponds to that of FIG. 8, the main multiplexer20 demultiplexer 4 is integrated with the analog / digital converters 2.

In the embodiment of FIG. 11, the modem 5 is connected to the compressor / decompressor unit 2, which in turn is connected to the main multiplexer / demultiplexer 4. This multiplexer / demultiplexer 4 is integrated with the analog / digital converters 2 and is connected to the switch 11.

In the embodiment of FIG. 12, modem 5 is connected to two-channel multiplexers / demultiplexers 41, which is connected to two compressor / decompressor units 3. The latter are connected to other, additional multiplexer / demultiplexer 41, which are also dual-channel and to which analog / digital converters 2 are connected. related to the interface circuits 20 to which the subscriber apparatus is attached.

With this solution, compression and decompression are simplified since, from a mathematical point of view, two-channel compression can be made easier, while 4-channel compression is very difficult.

Figure 13 shows a circuit for power supply to the subscriber side. In this case, a transformer 28 'is connected to the modem circuit 5' from the automatic telephone exchange. It has a primary winding 26 'and two secondary windings 21' and 22 ', these two secondary windings being of the same configuration and connected to each other by a capacitor 23'.

In this case, the electrodes of the capacitor 23 'are connected to a direct current source 27.

The modem 5 on the subscriber side is also connected to transformer 28, which is the same device as transformer 28 '. However, a DC / DC converter is connected to the capacitor 23 of the transformer 28, to which the various consumers on the subscriber side are connected. In this case, the ends of the two secondary windings 21, 22, respectively 21 ', 22' are connected to each other by means of connecting lines 20. In this way it is possible to transmit the signals and the supply voltage necessary for the operation of the subscriber side. This eliminates the need to insert a battery at the subscriber to supply the power supply.

Claims (6)

Claims 1. A messaging system, in particular a telephone system, comprising a line (6) for connecting subscribers to an automatic telephone exchange, at each end of which is connected a modem block (5,5 ') for modulating and demodulating data. according to the intended transmission, which modem unit is connected to a respective multiplexer / demultiplexer, wherein the subscribers are connected to bidirectional analog-to-digital converters connected to one multiplexer / demultiplexer and the switch of the automatic telephone exchange is connected to control circuits connected to the other multiplexer / demultiplexer, characterized in that the connection between the two-way analog-to-digital converters (2) and one multiplexer / demultiplexer (4) and between the control circuits (2 ', 12, 13 ) and the other multiplexer / demultiplexer (4 ') is performed by a corresponding compressor / decompressor unit (3,3'). Message system according to claim 1, in particular a telephone system including a line (6) for connecting subscribers to an automatic telephone exchange, at the two ends of which is connected a modem unit (5,5 ') for modulation and demodulating the data according to the intended transmission, which modem block (5.5 ') is connected to a respective multiplexer / demultiplexer (18.18'), wherein the subscribers are connected to bidirectional analog-to-digital converters (2) connected to one the multiplexer / demultiplexer (18) and the switch (1 1) the automatic telephone exchange is connected to control circuits (2 ', 12,13) connected to the other multiplexer / demultiplexer (18'), characterized in that the connection between the modem block (5,5 ') and the multiplexer / the demultiplexer (18,18 ') is implemented by a compressor / decompressor unit (17,17'). System according to claim 1 or 2, characterized in that, from the subscriber side to the main multiplexer / demultiplexer (4), in parallel with the telephones (1), computers, fax machines or telex machines (8,9) are connected to the subscribers. ), this connection being made through additional modems (10) and through other additional bidirectional multiplexers / demultiplexers (15,16), and from the automatic telephone exchange these devices are connected via control circuits (12,13) to the switch (11,11) ') through the country-specific chapter a multiplexer / demultiplexer (4 ') and with an intermediate includes additional multiplexers / demultiplexers (15,16). System according to Claims 1,2 or 3, characterized in that, in the case of switches (11) with analog signal control, the control circuits (2 ') connected to the telephones (1) on the side of the automatic telephone exchange represent two-way digital- analog converters (2 '), and control circuits connected to the apparatus on the same side are corresponding modems (12). System according to claim 1,2 or 3, characterized in that the switches (1D) with digital signal control, the control circuits on the side of the automatic telephone exchange have digital output signals. System according to any one of claims 1 to 4, characterized in that one transformer (28,28 ') is connected in parallel to the modem block (5,5'), from the automatic telephone exchange and from the subscriber. which symmetrically formed secondary windings (21,22,2G, 22 ') for each transformer (28,28') are connected by a capacitor (23,23 ') to each other, as to the electrodes of the capacitor connected to the PBX (23 ') is connected to a constant voltage source (27), and to the capacitor (23) of transformer (28) from the subscriber - converter n and a DC current of 5 DC (24), with the two ends of the secondary windings (21,22,2G, 22 ') of the two transformers (28,28') connected to each other by transmission lines. Attachment: 13 figures Expert: E.Tabova Publication of the Patent Office of the Republic of Bulgaria 1113 Sofia, 52-B Dr. GM Dimitrov Blvd. Editor: N. Bozhinova Cf. 37608 Circulation: 40 CS