SU1482540A3 - Device for exchange of information between telephone network subscribers - Google Patents

Abstract

The switching network (102), which contains switching matrices (104 - 110; 120, 122) arranged in several stages, is connected via common speech paths (204) with a group of interface devices (128), in which analog to digital and digital to analog conversion of the signals from and to the subscriber is carried out. Digital subscriber lines (130, 136, 138) are connected to the switching network 102 via a digital subscriber's apparatus (140). The translators which are present in the database (142) are used as usual to translate the digits keyed by the subscriber; however, they are also used for distributed control of the system, since they work with a single data connection path, which is only a speech path (204), between the interface device and the switching network. Since the interface units (128) control the establishment of connection paths to the switching network, the central processor which was previously required is omitted. This makes it possible to keep down the cost of testing when the program changes. <IMAGE>

Description

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The invention relates to multi-subscriber communication systems with digital switching, in particular to a distribution control system with a microprocessor in each line or branch, or on a support unit, the main element of which is a digital switching matrix.

The purpose of the invention is to increase the flexibility of service discipline.

FIG. 1 shows a block diagram of the proposed device; Fig. 2 shows the structure of a subscriber interface unit; in fig. 3 - the structure of the translator; in fig. 4 - interrelation of the common memory with other nodes of the device.

The device contains a switching matrix 1 of switching elements 2, a subscriber interface unit 3, a central interface unit 4, a group of translators 5, a shared memory 6, a service lines group /, two-way communication lines 8, subscriber inputs - outputs 9, individual digital subscriber lines 10, subscriber multi-channel system lines

11, digital trunk groups

12. The subscriber interface block contains interface nodes 13 and a multiplexer 14. FIG. 2 depicts the matching element 15, the analog-to-digital converter 16, the digital-analog converter 17, the speech conversion processor 18

in code, power supply unit 19, local memory 20, call control microprocessor 21 (e.g.

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microprocessor 8080), block 77. common memory interface, output switches 23 groups, input switches 24 groups. The translator (Fig. 3) contains a memory 25 of tables, a control processor 26, consisting of a control microprocessor 27 and a control memory 28, group connection points 29. FIG. 4 shows the translator 30, memory 31, interface nodes 13, links 32-35,

The device works as follows.

; Calls are managed | on the basis of the terminal interface 3f, which, at various points in time, processes the information to control both the source and the endpoint up-and-down; control by nor. ro /. p ojiv i o -g hh-jo

Frequency control (but 301 fn) of the power supply and call current, frequency response signal at frequencies: 300-3800 Hz and call processing. The speech processing is performed at the speech frequency by the processor 18 under the control of the microprocessor 21. Each two-wire subscriber line is connected to the high-voltage interface, the analog-to-digital converter 16 and the digital-to-analog converter 17, the digital output of the converter 16 is digitally filtered by the processor 18 and converted into a sequence digital converter for example, a 14-bit serial pulse modulation code, supplemented by additional bits for controlling the switching matrix 1 and for communication between different interface nodes and translational tori. As a result of digital filtering, a 2-wire signal is converted to a 4-wire signal and the loss characteristics of a given subscriber line or trunk are compensated for. The microprocessor 21 can be programmed to provide the equalization role, the loss and amplification of signals that change when switching lines. In addition, the output signals of the converter 16 with a frequency range of 300-3800 Hz are digitally filtered to drain the current. Processor 18 also produces digital signals and sends them to

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a transducer for receiving audio signals in the 300-3800 Hz band, corresponding to busy, ringing, and so on, on the reverse subscriber line.

The disc pulses and equivalent tone signals are received and processed by the microprocessor 21, which determines when further processing requires access to common databases and translators. A set of commands relating to the maintenance of trunk lines can be obtained from shared memory 6 through a memory access unit and via address information bus channels. This access is carried out by a separate supply unit or bus without using the switching matrix 1 to obtain this data. As a result, a distribution of software controls is achieved.

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master blocks can contain different combinations of software commands according to different types of lines / highways and their signs. Therefore, it is not necessary to store the entire set of software instructions on distributed media, which leads to memory savings. In addition, the interaction of software commands with one another by means of standard interface lines is prevented with the help of switching matrix 1. This facilitates the possibility of modifications, additions and removal of elements. A specific processor has access only to the initial or final half of the call, depending on the direction of the latter. A block synchronization channel, an address information bus, and request / enable lines are connected to block 22, which, together with the main clock signal, provide the specified inter-module communication.

The proposed distributed control system, in which call control is distributed in such a way as to allow exclusive use of one microprocessor in a KJAD call, eliminates the need for complex separation algorithms for sharing a single processor during simultaneous calls. Distributed control can be done using

One microprocessor is used for branching, a terminal device or a security unit. In accordance with the invention, each terminal device, i.e. line or trunk, supplied with a microprocessor, which may mean, for example, a microprocessor on each subscriber line. In all cases, the microprocessor is attached to the line for the time during which it is output.

FIG. Figure 4 shows a general program structure with 60 terminals, which can be considered as one supply unit. Each end-interface node 13 connecting the subscriber lines with a switching matrix, as mentioned, performs the conversion of a two-wire signal into a four-wire signal, converts the incoming analog signals into digital ones, performs digital filtering and other conversions on the voice frequency, and also controls calls. An individual memory microprocessor attached to such a circuit performing call control, translation, channel selection, signal generation and various diagnostic functions is connected to the common memory 31 via block 22 to node 13. In accordance with FIG. 4 shared memory 31 shared among themselves 60 end interface nodes 13. Each line, for example line 32; multiplexedly connected to the 32-channel group of lines 33, i.e. to the usual. data transmission paths carrying serial 14-bit pulse-coded information with a frequency of 8 kHz. Two of these channels can be used to communicate with modules of other systems in accordance with the clock signals from the common memory 31 and from the master oscillator of the system.

Each end processor typically has an individual 4 KB memory and the ability to access shared memory used by multiple microprocessors, which is typically 256 KB.

Both the program memory and the fixed data memory are shared, however the individual memory, which is also provided with some basic commands, between the microprocessors

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is not divided to minimize interaction between them. In any shared memory system, there are problems associated with simultaneous requests for memory, additional time spent accessing certain parts of the shared memory, and complicating the circuit and software devices that have to solve these problems.

The transmitter 30, the terminal interface nodes 13 (60 in accordance with FIG. 4) and the common memory 31 interact with the switching matrix.

FIG. 3 shows the translator 30, the latter is particularly convenient to use in a system with distributed control. It operates with a single data transmission channel between the modules of the supply unit and other subsystems participating in the exchange, which is performed in the switching matrix 1. Translator 30 may be duplicated as needed, arising as the network grows, for reliability and longer service life.

The translator 30 receives information about various types of services, payment data, statistical data, etc., while performing the usual translation functions, i.e. conversion of the telephone number (TH) into the equipment number (NO) by referring to the table in memory 25, reverse conversion of the HO / TH number of the equipment into a telephone number, translation of the area or station code into the trunk code, and the trunk code into the equipment number.

Each speech interface node 13 is connected to two terminal multiplex lines, each of which contains 32 channels and is connected to the outputs of the end switches,

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which, in turn, are connected to the inputs of the switching matrix. In particular, in a typical PBX structure, 960 end circuits, identical to node 13, are connected to a switching matrix. Each of the thirty end circuits connected to one end multiplex line has a second end device for connecting to the second end multiplexer so that the two end multiplexes are connected circuits common to thirty end lines are connected to

outputs with the same numbers from two consecutive levels of switches, 60 end circuits with common program memory are connected to four terminal multiplexers, so four sets of four terminal multiplexers are connected to each pair of switches of the new level. Thus, each interface channel 13 of the voice channel corresponds to two equipment numbers, and the TH / BUT transmitter function continuously controls the state, i.e. conditions of occupation and freeness, of each initial and each final call of the call from the voice terminal node. The response to the GNU translation command contains the number of free equipment and the data on the occupancy of the second number of equipment. If both windows are busy, this information is sent to the microprocessor 26, the control of the initial half of the call, and it chooses the path in the network leading to the end with the desired equipment number, and sends the call setup information. The microprocessor, which controls the terminal half of the call, sends a confirmation signal to the TH / HO translator or to another translator function, to confirm the occurrence of an end-of-operation condition and to identify the equipment from which the call came.

Translator memory 25 can be a memory on magnetic or solid-state elements, elements of any type, the size of which is not less than 90 Kbytes, 80 of which are allocated to the memory of the translator, and 10 kbytes - for the backup program of the translator and the byte length is, for example, 16, 24 or 32 bits depending on the data structure. Nodes 29 are electrically identical with speech nodes 13 connected to the switching matrix, and can be identified by equipment number in the same way as the termination circuits. The distribution of nodes 29 is carried out so that the failure of the switching module leads to the disconnection of no more than one node, and the failure of the first level switch leads to the disconnection of no more than half of such blocks. Equipment numbers assigned by nodes 29 are knocked out so that the algorithm containing

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In memory of program memory 28, any other equipment number can be determined by any given equipment number. Each connection node functionally contains means for reading a multiplex line carrying a pulse-encoded signal, a channel content, which is determined by the equipment number, means for identifying inter-microprocessor control messages on this channel, a buffer register for storing one or more such messages, the output buffer, the means for directing these messages, to the proper channel on the output end multiplex lines, and the means for outputting the messages, releasing the communication channel and while the translator microprocessor 27 is producing the output data.

The nodes 29, as mentioned, also contain input lines. The data is read from the memory 25 of the translator into (, the response to the signals arriving at the input blocks, and the recording and modification of data in the memory 25 occurs under the control of the microprocessor in accordance with the program contained in program memory 28. The processor 27 may be the same microprocessor that is used in the interface nodes 13 and is also shown at number 21. The translator memory contains the required translation tables.The accuracy of the broadcast time exceeds 4 ms , not exceeds one thousand, and the average broadcast time is less than 2 ms. Modifications of subscriber data and service data are performed by changing the program in memory 28 so that it takes into account changes in subscriber characteristics or an increase in the number of lines and trunks served station.

Claims (1)

Invention Formula A device for exchanging information between subscribers of the telephone network, comprising a switching matrix consisting of a group of switching elements connected in a hierarchical structure connected through a central interface to individual digital subscriber units. lines, subscriber multichannel system lines and digital trunk groups, a common memory, a group of translators and a group of service lines connected by two-way communications to the switching matrix, subscriber interface blocks connected by two-way communication switching matrix, and each JQ in addition, each interface node 15 20 subscriber interface unit contains a group of interface nodes, inputs - outputs of which are inputs - outputs of the device for connection to subscribers, and a multiplexer, each interface node contains a matching element, the first inputs and outputs of which are input - output of the block, and the second input and the output is connected respectively to the output of a digital-to-analog converter, the input of which is connected to the first The first input of which is connected to the input of a digital-to-analog converter, and the second information input and output are connected respectively to the information inputs of the group input switches and the information inputs of the group output switches, the information inputs of the group switches and information outputs the output switches of the group through the multiplexer are connected to the inputs and outputs respectively 30 35 contains a local memory, characterized in that, in order to increase the flexibility of the service discipline, a microprocessor for call control is inserted into each interface node of the subscriber interface unit and connected by two-way information and address control links to the local, input and output the interchangeable group and the unit of interchange with the price of memory, while the translator contains the memory of the tables, the control processor, the Toqii; nn processor from the control microprocessor connected to the control memory, and the group of connection nodes and, the first inputs - outputs coupled to data and control buses of the microprocessor control, informational, address and the control bus is coupled with similar memory tables tires, the inputs and outputs of nodes connected to the connecting group sostvetstvukshschmi switching elements the switching matrix. here nppcvvM tee yg x temenmen IOD com 1 iru tea, IKci, with memory lock, address information bus and resolution bus of which are connected to common memory buses of the same name, the sync input of which is connected to the synchronous input and output group switches , contains a local memory, characterized in that, in order to increase the flexibility of the service discipline, a microprocessor for call control is inserted into each interface node of the subscriber interface unit and connected by two-way information and address control links to the local, input and output the interchangeable group and the unit of interchange with the price of memory, while the translator contains the memory of the tables, the control processor, the Toqii; nn processor from the control microprocessor connected to the control memory, and the group of connection nodes and, the first inputs - outputs coupled to data and control buses of the microprocessor control, informational, address and the control bus is coupled with similar memory tables tires, the inputs and outputs of nodes connected to the connecting group sostvetstvukshschmi switching elements the switching matrix. I Phases. one