CH646828A5 - Telephone exchange system with a coupling network containing multiple coupling elements - Google Patents

Description

The invention relates to a telecommunication switching system 20 with a switching network and Vdelfach switching elements arranged therein for the optional establishment of connections forming connections between connections, with distributed processors for control functions.

In modern telephone switching systems, it is necessary that data relating to the state of subscriber lines and long-distance connections are stored in the switching network together with the necessary state-dependent processes.

Such data can relate to the connection setup 30 in the switching network, the type of subscriber lines, the type of long-distance connections, call conversions, etc.

From US Pat. No. 3,974,343 and from US Pat. No. 3,860,761 it is known to decentralize the control of a switching system. In both of these known devices with decentralized control functions, central devices are also provided which control the data exchange between the decentralized devices. If, for example, the switching system is to be expanded, this can only be done to the extent permitted by the size of the central facility. This has the disadvantage that the central facilities of these known telephone switching systems must also be appropriately designed in small systems in order to be able to "expand the system later, if necessary.

The aim of the invention is to design a telephone exchange so that changes or extensions are possible at any time without particular difficulty. so

The invention has for its object to provide a telecommunications switching system, the control devices are largely decentralized.

The solution to this problem is obtained by the features specified in claim 1. When using a coupling network, as characterized in more detail in claim 10, a particularly advantageous embodiment of the invention results. The multiple coupling elements characterized in claim 60 are particularly suitable as coupling elements for use in the coupling network of the telecommunication switching system according to the invention.

The invention is described below using the drawings as an example. Show it:

1 is a block diagram of a decentralized 65 telecommunication switching system according to the invention,

2 shows the possibility of modular expansion of the coupling network belonging to the system,

3 shows a simplified block diagram of an associated multiple coupling element,

Fig. 4 shows a level of. Coupling network,

5A, 5B, 5C and 5D, the expansion of the coupling network,

6 is a block diagram of a connection subunit for subscriber lines,

7 is a block diagram of a connection subunit for connecting lines,

8 shows a simplified illustration of the time multiple bus line of a multiple coupling element,

9 is a block diagram of the logic of an input / output device of a multiple coupling element,

10 (a), 10 (b), 10 (c), 10 (d) and 10 (e) examples of the channel word structure used,

1 l (a), 1 l (b), 1 l (c) and 1 l (d) further possibilities of the channel word structure,

12 shows a typical connection between connection units by means of the coupling network,

13 (a), 13 (b), 13 (c), 13 (d), 13 (e), 13 (0.13 (g) and 13 (h) timing diagrams relating to the operation of the coupling elements,

14 (a), 14 (b), 14 (c), 14 (d), 14 (e) time diagrams in more detail, which relate to the operation of the coupling elements, and

15 shows the line assignment of the time multiple line of a coupling element.

1 shows a block diagram of a decentralized, digital switching system which contains a switching network 10 via which a multiplicity of connections between connection units can be switched through in order to provide transmission paths for the data exchange between connection devices which are operated by the connection units. A multi-level switching network is referred to below as a group switch. * "

A connection unit is used as a subsystem for operating a group of connections that end in a first coupling stage in each level of the group switch. Each connection unit contains 8 access switches, via which data coming from the connections are transmitted to and from the group switch 10.

A connection subunit is a subsystem of a connection unit that serves a group of connection units that end in a pair of access switches provided for security reasons.

For safety reasons, each connection unit contains four pairs of access switches. With each connection unit, the PCM data are derived, for example, from telephone line devices.

The connection units 12, 14 and 16 are shown as representative; however, up to 128 connection units or even more are switched by the group switch 10.

Each connection unit has the ability, for example, to connect 1920 subscriber devices or 480 long-distance lines by means of 4 connection sub-units each (by means of the sub-units 18, 20, 22 and 24 which are shown for the connection unit 12).

Digital PCM multiplex lines with 32 channels carry 30 bidirectional subscriber lines and are connected to the connection units.

Every connection unit, e.g. the connection unit 12 is connected to a group switch 10 by a multiplicity of multiplex transmission connections, each of the transmission connections containing two directional transmission paths. Each sub-unit 18, 20, 22 and 24 of the connection unit 12 is connected to each level of the group switch 10 by two such transmission connections, which is why the transmission connections for the sub-unit 18

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gen 26 and 28 are shown, which connect the subunit 18 to level 0 of the group switch 10. The connections 30 and 32 couple the subunit 18 to the level 3 of the group switch 10.

The subunit 18 is connected in a similar manner to the levels 5 and 2 of the group switch 10. The sub-units 20, 22 and 24 are also connected to each level of the group switch, as is the case with the sub-unit 18.

Each connection 26, 28, 30 and 32, which are shown for the subunit 18, is designed to be bidirectional and for this purpose contains a pair of directional transmission paths, each path being intended for a direction of the data flow. Each directional transmission path carries 32 channels of digital information, which is transmitted in time division multiplex (TDM) serially in binary code. Each frame of the time division multiplex format consists of 32 channels, each channel carrying 16 bits of information. The bit rate is 4096 Mb / s. This transmission rate is the same in the exchange, so that the system can be referred to as bit rate-synchronous 20.

As will be described later, the system is phase-asynchronous so that there is no particular phase relationship to the data bits in a frame that are received by different coupling elements or by different inputs / outputs in a single coupling element. This bit rate-synchronous and phase-synchronous system is inserted into the group switch and into the access switch by a multitude of multiple coupling elements. If digital voice samples are transmitted anywhere within the system to 30 or from a single terminal, these samples must be time-division multiplexed into the correct channels on the transmission link between switches. The coupling elements are used for the connection of the terminal devices. An exchange of the 35 time slots is provided for each coupling element, since the channels for the connection between the connection units can vary.

The exchange of the time slots, i.e. the transfer of data from one channel to another is known. As will be described below, a unitary multiple coupling mechanism is provided which contains a coupling element with 16 inputs / outputs, which functions as a 32-channel time switch and as a room switch with 16 inputs / outputs, in particular for all inputs in less than one unique frame time.

The digital voice samples can contain up to 14 bits from a 16-bit channel word, with the remaining two bits used as protocol bits (to identify the type of data in the other 14 bits of the channel word). Thus, the coupling element with 16 inputs / outputs can be used, for example, for the following encodings: 14-bit linear PCM samples, 13-bit linear PCM samples; 8-bit compressed PCM samples; 8-bit data bytes, etc. The inputs / outputs can also be called gates. 55

Two groups of processors are included in each port subunit, such as subunit 18. The first group of processors is shown as processors Ao, Ai, ... An, which are each assigned to a separate group of line units, which are referred to as line bundles, 60 and which carry out a special group of processor functions, as well as the establishment of a transmission path via the group switch 10 and the provision of a connection interface for the connection units within the connection bundle. Bundles with a high traffic load, such as 65 long-distance telephone lines, can include up to 30 line units, whereas bundles with a low volume of traffic, such as telephone subscriber lines, can include up to 60

Connection units can contain. Each connection unit can be connected to up to 4 bundles of heavy traffic; consequently, this sub-unit contains 4 type 4 processors, while a low-traffic sub-unit can be connected to 8 bundles of low traffic load and consequently contains 8 type A processors. Each A processor can, for example, be a type 8085 microprocessor from Intel Corp. included as connection interface and assigned RAM and ROM memory. Thus, for example, each connection unit may contain up to 1920 connections with little traffic (for subscriber lines) or 480 connections for long-distance lines with high traffic volume. Each connection bundle, such as the connection bundle 36 in the subunit 18, contains an A processor and its associated connection interface.

This connection interface provided for the connection bundle is coupled to each of the two access switches 42 and 44 within the subunit 18 by a pair of non-directional connections 38 and 40. The access switches 42 and 44 of the subunit 18 are of the same coupling element construction as the coupling elements of the group switch 10. The access switches 42 and 44 enable for. subunit 18 provides access to one of a pair of a second group of processors, such as processors Bo and Bi in subunit 18. Other pairs of type B processors are included in port subunits 20, 22 and 24, but for that The description shows only the B processor of subunit 18. This second group of processors, the B processors, is intended for a second group of processor functions, such as call control (processing of call data, analysis of signaling, conversions, etc.) for the line units that are connected in the subunit 18. A commercial microprocessor can also be used for this purpose. For security, a pair of processors have been provided by combining identical processor functions in the B processors 46 and 48. Access switches 42 and 44 for subunit 18 thus allow each port bundle, such as the Ao bundle, to select one of the paired processors, i.e. either the B processor 46 via the access switch 42 or the B processor 48 via the access switch 44. If an error occurs in one of the two processors provided for security reasons, an alternative route is therefore available.

The group switch 10 shown as a matrix in FIG. 2, which was generally referred to in FIG. 1 as a coupling network and which can also be referred to as a group switch matrix, has four independent levels of switching options: the first level is 100, the second level is 102 , the third level is labeled 104 and the fourth level is labeled 106.

A multitude of levels is provided in order to fully meet the traffic and service requirements for the individual applications of the system. In a preferred manner, 2, 3 or 4 switching levels are provided which serve 120,000 or more connection units, i.e. Subscriber lines that end in the subscriber circuits mentioned above.

Each switching level can contain up to 3 levels of coupling elements, which is considered the preferred version. The access circuit, which selects a single level for a connection, is arranged within the individual connection unit 12. For example, the access switch 42 in the subunit 18 can select: the first level 100 via the connection 26 or the fourth level 106 via the connection 30.

The group switch 10 is either by increasing the

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Modularly expandable number of levels to carry out the processing of higher traffic, or by increasing the number of stages of the coupling elements or the number of coupling elements per stage in order to increase the number of connection units operated by the group switch. The number of stages per level of the group switch 10 is modularly expanded for typical applications as follows:

Connection

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3 shows a basic multiple coupling element 300 according to the invention, from which all switching stages are formed, and which is shown as a multi-directional switch with 16 inputs / outputs (gates with an undefined direction of traffic). The number of inputs / outputs can also be greater or less than 16. A multidirectional switch can be defined as a coupling element which has a large number of inputs / outputs for bidirectional transmission, in which data received at each input / output can be switched and transmitted to any input / output (either the same or a different one) Input / output of the coupling element). In operation, the entire data transfer from one input / output to another input / output within the switch 300 is performed by a time-division multiplex bus 302 with parallel bit transfer. This enables spatial switching, which can be described as providing a transmission path between any two inputs / outputs within the coupling element.

Each input / output 0 to 15 of the multidirectional switch 300 contains its own reception logic Rx 304 and its own transmission logic Tx 306, which are shown as an example at input / output 7. Data is transmitted to and from each input / output (e.g. input / output 7) of the coupling element 300 by coupling elements with a similar structure, to which the coupling element 300 is connected via a reception control line 308 and a transmission control line 310, which transmit bits in series, and with the system clock of 4096 Mb / s, whereby 512 serially transmitted bits form a frame which is divided into 32 channels of 16 bits each.

The data transmitted serially from the 16 inputs / outputs are synchronized in speed and phase, i.e. the transmission logic 306 and the corresponding transmission logic for the other 15 inputs / outputs of the coupling element 300 transmit at the same speed of 4096 Mb / s and transmit the same bit position of a frame at all times. On the other hand, the reception of serial data bits at the receive logic 304 of the input / output 7 and at all other inputs / outputs of the coupling element 300 is only synchronous with regard to the speed, i.e. there is no need for a fixed time relationship to receive bits in two inputs / outputs. The reception is therefore phase-asynchronous. The receive logic 304 and transmit logic 306 each include a control logic portion and a random access memory, which are described in FIG. 9.

4 shows a level of a group switch 10 (first level 100). As described in FIG. 3, the coupling elements 108, 110, 112, from which the group

is set up at the switch level, multi-directional switch 300 with 16 inputs / outputs. The function as input or output is only defined by definition depending on the position in the coupling network.

In the three-stage group switch level shown, the inputs / outputs 0 to 7 of the coupling elements 108 and 110 in stages 1 and 2 are determined as inputs and the inputs / outputs 8 to 15 are determined as outputs.

Thus, these multiple coupling elements can be referred to as two-sided, whereas in stage 3 all coupling elements, such as coupling element 112, are designed on one side, i.e. all gates serve as entrances in terms of traffic.

If any group switch stage is considered and if the network is to be expanded on a modular basis, then such a stage is initially switched as a two-sided stage, with outputs reserved for the expansion. However, if the switching network allows one stage to connect more than half of the maximum required connections to a multiple coupling element of this stage, then this stage is designed on one side. This allows continuous modular expansion up to the maximum required network without having to change the connections between the levels.

The modular extension of the multiple coupling element 300 to a switching level 100 is shown in FIGS. 5A to 5D. 5 A shows the size of the group switch level with a multiple coupling element which is required for connecting a connection unit with 1000 subscriber lines. The input / output point 0 can thus be connected to the line 26 of the subunit 18, while the input / output points 1 to 7 are connected to other access switches in the connection unit 12. Input / output positions 8 to 15 are reserved for network expansion.

5B shows an example of the next expansion stage of group switch level 100, namely for two connection units 12 and 14. Thus, two coupling elements per level of the group switch are provided for the first stage, with each level in the second stage coupling elements such as e.g. 0,1,2 and 3 has to connect the two coupling elements of the first stage with each other. The outputs at the second stage are reserved for later network expansion, whereby this network (one level of which is shown) serves over 2000 subscriber lines.

5C shows an example of an expansion of the switching level 100 in order to operate 8 connection units. The coupling elements of levels 1 and 2 are completely interconnected and only the outputs of level 2 can be used for further expansion, so that in order to connect additional groups of up to 8 connection units, a third coupling level per level must be added, as this is shown in Fig. 5 D, which shows 16 connection units which are coupled to the extended group switch level. The network shown in FIG. 5C can serve approximately 10,000 subscriber lines and the network shown in FIG. 5D can serve approximately 20,000 subscriber lines. The non-interconnected input / output points shown in Fig. 5B, 5C and 5D are available for expansion and each level of the network - e.g. FIG. 5 D - is expanded by the connection of these input / output points, for example, to form a network, as shown in FIG. 4, which has a capacity of more than 100,000 subscriber lines.

6 shows a subunit 18 of a line connection unit which contains up to 8 connection bundles 36, each of these bundles including 60 subscriber lines, an interface for a connection unit and a type A microprocessor. Three of these connection bundles are labeled 36, 37 and 39. The access switches 180

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and 181 of subunit 18 serve 8 connection bundles, of which only three are shown for the sake of simplicity. Each interface for a connection unit, such as interface 190, is assigned, for example, 60 subscriber lines and 60 subscriber circuits. An A processor 198 is also connected to the interface 190, which has certain processing tasks, e.g. Establishing a connection through the coupling network or controlling the connection unit. Each interface 190 has a bidirectional transmission line 199 which is connected to an input / output point of the access switches 180 and 181. Each access switch, which contains a coupling element with 16 input / output points (FIG. 3), allows the levels of the group switch 10, e.g. via outputs of the input / output points 8, 10, 12, 14, or a B processor 183 via an output, such as the output of the input / output point 9, this B processor carrying out tasks other than call control. Unused outputs 11, 13 and

15 of the access switch are free and are available for the equipment of other elements such as alarm devices, monitoring circuits, diagnostic controls, etc.

FIG. 7 shows a connection subunit which is functionally identical to the subunit of the line connection unit which was described in FIG. 6; however, it serves a smaller number of entrances with heavy traffic. In order to take into account an increased traffic load on the transmission line groups compared to the line connection units, the subunit of the transmission line connection unit contains up to 4 connection unit interfaces, each of which is assigned, for example, 30 transmission line connection units. Thus, inputs 4 through 7 on each output switch 180 and 181 are unused in this arrangement. The trunk groups 60 and 61 of the total of 4 trunk groups are shown in FIG. 7, each of which contains a connection interface 62 and 63 and an A processor and a memory 64 and 65, respectively.

The B processor 66 and the associated memory 67 are coupled to the output switch 180 and the B processor and the associated memory 69 are coupled to the access switch 181. These access switches have the same structure as described in Fig. 6 and can include a commercial microprocessor.

Coupling element 300 already described in FIG. 3 with

16 gates will now be further described in FIG. 8. Every gate, e.g. Gate 15 of the coupling element 300 consists of a reception logic 304, a transmission logic 306, the inputs and outputs of directional transmission paths 308 and 310 and a parallel time-division multiplex bus 302 can be accessed within the coupling element 300.

In a preferred exemplary embodiment of the invention, the connections are made by the coupling element 300 on the basis of directed (simple) paths. A simple connection between an input channel of a gate (one of 32 channels) and an output channel of any gate (of 512 channels) is made by a channel input command corresponding to a selection command. This selection command is contained in a single 16-bit word in the input channel that requests a connection. A coupling element enables a number of different types of connections, which are distinguished by the information in the selection command. Typical selection commands are: «Gate channel»; this is a command which is received by the gate's receive logic and which establishes a connection to any free channel of any gate. «Gate N-channel»; this is another selection command that selects a connection to any free channel of a particular port N, i.e. for example gate 8. «Gate channel M»; This is a selection command that causes a connection to a special channel M (e.g. channel 5) of a specific gate N (e.g. gate 8). Other special selection commands such as "connect to any odd-numbered (or even-numbered) gate" and special commands relating to channel 16 and stop commands in channel 0 are within the range of the performance of the switching module (part of which is comprised by a module), which is more fully related is explained with Fig. 9.

The receive logic 304 synchronizes the data arriving from other switching elements for each gate. The channel number (0 to 31) of the incoming channel is used to get the desired gate and the channel addresses from the corresponding memories - I / O RAM, channel RAM. During multiple module access to bus 302, receive control logic 308 in the channel sends the received channel word along with the destination gate and channel addresses to time-multiple bus 302 of switching element 300. In each bus cycle (time interval in which data is transmitted from receive control logic 308 to transmit control logic 306 ), each transmit logic at each gate searches for its gate address on the time line 302. If the gate number on the line 302 matches the individual address of a particular gate, then the data (channel words) of the line 302 is stored in the data store of the matcher Tores registered, namely at the address that was read out of the channel memory for the reception control logic of the gate. This means the data transmission of a word from the reception control logic via the time multiple bus 302 of the reception control logic via the time multiple bus 302 to the transmission control logic of a gate.

The transmission and reception control logic of a gate can e.g. Operate as follows: The data from line 308 is input at 4096 Mb / s to input synchronization circuit 400 which inputs bit and word synchronization circuit 400 which provides bit and word synchronization of the information on line 308. The output signal of the input synchronization circuit 400 is a 16-bit channel word and its channel number (which indicates the channel within the frame) is written into a buffer register 402, which operates on the principle of "first input equals first output" and that is on line 403 incoming data is synchronized with the timing on the multiple line 302. This is necessary because the data on line 308 is asynchronous to the time scale on multi-line 302. The output of buffer register 402 is a 16 bit channel word and its 5 bit channel number. The information contained in the 16-bit channel word indicates the type of information contained in the word. This information is contained in the so-called protocol bit of the channel word and, together with information in the reception control memory 404, identifies the actions to be carried out by the reception control circuit 406 for this channel in this frame.

The following 5 types of actions are provided in the example: LANGUAGE, CHOICE, QUESTION, INFORM and FREE. If the protocol bits indicate LANGUAGE (voice and data words), the channel word is transferred unchanged to bus 302 and the channel address and destination gate are fetched from channel memory 408 and gate memory 410 and open during the channel access time associated with that gate the manifold 302 given. If a SELECT command allows any gate and channel, then the first free gate selection circuit 412 selects transmit logic with a free channel to perform a free selection. During the access time for

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The reception logic of the time multiple bus line 302 is carried out a free selection in the selected transmission logic at the selected gate, which returns a free channel number from its first free selection circuit 414. A blocking receiver 416 checks the content of the channel 16 for signs of unsuccessful 5 path searches from subsequent stages of the switching network, which are given by the transmission logic 306 of this module. The lock search logic 418 checks the reception control memory 404 for channels that are locked and causes the channel numbers of the locked channels in the transmission logic 306 10 in channel 16 to be deleted.

The transmit logic 306 checks the state of the gate address lines of the multiple line 302 with the module identification code in the gate decoding logic. If the correct gate address is decoded at the decoder 420 and the dialing line of the multiple line 302 is inactive, then the contents of the LANGUAGE lines of the multiple lines 302 are written into the data memory 422, the address from that specified on the address lines of the multiple line 302 Address is derived. 20th

If the SELECT line of the multiple line 302 is activated and a free selection is desired by a reception controller 406 (selection of any free channel),

then no write-in operation occurs in the data memory 422, but the free selection circuit 414 sends a free 25 channel number back to the requesting reception logic.

The data memory 422 is a time channel converter, which is read sequentially with the aid of a counter contained in the transmission clock 428. The words read out from the data memory 422 20 are input into a parallel / serial conversion register 430, which outputs the serial bit sequence at 4096 Mb / s onto the transmission line 310. The word entered in output register 430 can be changed to channel 0 or 16. In channel 0, alarms of line 432 35 are inserted (for troubleshooting) and the information about blocked channels is, if necessary, inserted into channel 16 by logic 434. The transmit control memory 426 contains the state for each outgoing channel. The transmit control logic 424 coordinates the reads and writes for 40 the data memory 422, the transmit control memory 426, the free selection circuit 414 and for loading the output register 430.

The following is now the establishment of connections between the connections via the coupling network 45

described.

As already mentioned, the coupling elements with 16 gates enable both a time and a space switching function for all transmission paths. The information arriving on the incoming route at any gate in any channel can be transmitted by the coupling element with 16 gates to the outgoing route of each gate, which corresponds to a space switching function, and to any channel of this outgoing route, which corresponds to a time switching function. All voice and data (LANGUAGE) transmissions over the network are the result of individual gates of the multi-port coupling elements and include a transformation from the input channel (one of 512 channels) to the output channel (one of 512 channels) is determined in route searches. There are 32 60 channel words in a frame on each existing transmission path. Figure 10 illustrates an example of a channel word structure that can be used with channels 1 through 15 and 17 through 31, all of which are LANGUAGE channels. The channel word structure for channels 0 (operational and synchronization channel) and 16 (channel for special control processes, locking processes, etc.) is illustrated in FIG. 11.

The LANGUAGE channels can be used for digital

Voice transmission as well as for information exchange between the control computers can be used. When speech is transmitted, 14 bits per channel word are available for a PCM-encoded sample and two bits for network protocol selection. If the channel is used to control the connection setup, 13 bits per channel word are available for signal information and 3 bits for protocol selection. The channel word structure allows switching through the entire switching network, this includes a connection via several such switching elements with 16 ports. These connections have only one direction. Two such one-way connections are required for two-way connections.

10 (a) to 10 (e) show the data structure for the processes: CHOICE, QUESTION, INFORM, LANGUAGE or FREE. 11 (a) to 11 (d) illustrate the channel word structure for the processes: SELECT, INFORM, HALT and FREE for channel 16. For channel 0 there is a special channel word structure for the process ALARM, and the channel words in channel 0 also contain the frame synchronization bit pattern (6 bits) for the synchronization between adjacent coupling elements with 16 gates.

The CHOICE command establishes a connection via a coupling element.

The QUESTION command is used after establishing the connection to determine which gate was selected for this connection within the coupling element.

After a connection has been established, the INFORM command is used to transmit signal information between two trunk groups and to distinguish them from the transmission of digitized speech information.

The LANGUAGE structure is used to transmit voice or data information between two connections.

The channel word structure FREE indicates a free channel.

11, the CHOICES, INFORM and FREE commands are similar to the commands explained in connection with FIG. 10, but there is no LANGUAGE command, the QUESTION command is not required, and since channel 16 contains the blocking channel, there are a small number of CHOICE commands. The HALT command maintains a connection in channel 16 after it has been established by CHOICE commands. Channel 0 is reserved for service tasks and troubleshooting in the network.

FIG. 12 shows, among other things, a connection subunit 18, which shares in an access coupling device, namely the access switches 42 and 44 shown in FIG. 1.

includes. 12 also shows the group switch 10, which comprises three coupling stages. To simplify the illustration, the individual levels in the group switch and the individual coupling elements in each coupling stage of the group switch are not shown.

A connection over the switching network is made from a connection circuit 690 to another connection circuit 190 or from a B processor 183 to another processor, e.g. the A processor 198 connected to the connection circuit 190. In doing so, a series of SELECT commands in the channel assigned to this connection are inserted in successive frames in the PCM bit sequence between the source connection circuit (or processor) and the access coupling device. A SELECT command is required for each path section and each coupling stage.

A connection via the switching network is established from a series of connections via individual switching stages. The connection is established progressively from switching stages of lower order number to switching stages of higher order number as a connection between one

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Input and an output via a coupling element until a certain reflection coupling stage is reached.

A connection between two input gates of the same coupling element is referred to as reflection; this makes it possible to establish connections via the coupling network without occupying an unnecessarily large number of coupling stages. Details of such reflections are not the subject of this application.

In the reflection coupling stage, an “input to input” connection is thus established via the coupling element, then a progressive connection is established from a coupling stage with a higher order number to coupling stages with a lower order number by establishing “output to input” connections via the corresponding coupling elements.

The reflection coupling stage is determined on the basis of the specific network address of the desired connection circuit 190. The corresponding rule can generally be referred to as follows:

If the final connection circuit is in the same connection subunit, then the reflection takes place in the access coupling stage.

If the final connection circuit is in the same connection unit, then the reflection takes place in coupling stage 1 of the group switch. If the final connection circuit is in the same group of connection units, then the reflection takes place in coupling stage 2 of the group switch.

In all other cases, the reflection takes place in coupling stage 3 of the group switch.

1 and 4, which show individual features of the network configuration. Afterwards, a connection unit 12 has eight bidirectional transmission lines to each level of the group switch, e.g. to the level 0 shown in FIG. 4, these transmission lines end with a coupling element in each level. The coupling element has a unique address when viewed from the third coupling stage. With reference to FIG. 4, it can thus be said that, for example, the coupling element 108 is reached from the perspective of any coupling element in the third coupling stage via the input 0 of the third coupling stage and subsequently the input 0 of the second coupling stage. This forms the address of the connection unit, which is referred to below with the expression TU (0, 0). In addition, a connection sub-unit within a connection unit is designated once with regard to the inputs to the second coupling stage, with reference to FIG. 1, e.g. the connection sub-unit 18 is referred to as the TSU (0) of the connection unit TU (0, 0), since it is addressed once via the inputs 0 and 4 of the first coupling stage (0, 0). Similarly, each connection circuit in each connection bundle is identified by its input address at the access switch. Therefore e.g. the address of the connection circuit 190 of Fig. 12 viewed from any other connection circuit, e.g. the connection circuit 690 in the connection unit 16, regardless of which coupling element is used as the reflection point in the third coupling stage.

This allows the A processor 698, which controls the connection establishment, to send the sequence of dialing instructions given below to the network in order to establish a connection to the connection circuit 190, the network address of which has the form (a, b, c, d), for example. Has.

Frame 1. CHOICE, EVEN GATE, ANY CHANNEL: This establishes a voice connection via the access switch to a level of the group switch.

Frame 2nd CHOICE, ANY GATE, ANY CHANNEL: This establishes a connection via coupling stage 1

the selected level.

Frame 3. CHOICE, ANY GATE, ANY CHANNEL: This establishes a connection via coupling level 2 of the selected level.

Frame 4. CHOICE, GATE (a), ANY CHANNEL: This reflects the connection via coupling stage 3 to coupling stage 2.

Frame 5. CHOICE, GATE (b), ANY CHANNEL: This establishes a connection back via coupling stage 2.

Frame 6. CHOICE, GATE (c), ANY CHANNEL: This establishes a connection back via coupling stage 1.

Frame 7. CHOICE, GATE (d), ANY CHANNEL: This establishes a connection back via the access switch to connection circuit (a, b, c, d).

The coupling network allows a connection to be made forward to the reflection point in the previously determined reflection coupling stage and back via the network with a fixed address which is independent of the reflection coupling element in the reflection coupling stage.

This sequence of SELECT commands can be used by any connection unit to establish a connection to the connection unit TU (a, b, c, d), and the selection mechanism described above for the first free channel in each case ensures the establishment of a connection with as little as possible Transmission delay on the chosen route. If, based on the rule explained above, it is found that earlier reflection is possible in the low-order switching stage, then a subset of the above command sequence is used. For example, the B processor 183, which is located in the same connection subunit 18 as the connection circuit 190, only issue the following partial command from the above command sequence:

Frame 1st CHOICE, GATE (d), ANY CHANNEL.

The functions carried out by the A and B processors depend on the computer programs used in each case, but some exemplary functions can be specified: connection control, this gives the characteristics for each service class of the subscriber or transmission lines; Signaling control, this generates characters for microphone units based on the work of the connection control and decodes and interprets sequences of characters and signals, which are communicated to the connection control computer for processing as telephone events; Coupling control, this function establishes connections, maintains them and breaks them down again in the coupling network, as determined by the functions of the connection control and the signaling control; Basic data control, this function carries out all operations at the data level and allows all other processes to take place independently of a particular organization of the data level; and hardware control, this function combines processes for the control of the hardware, which ultimately forms the interface to subscriber lines and transmission lines, and processes for the connection units and coupling elements. An example of the distribution of these processing functions is the assignment of the hardware control for up to 60 subscriber lines or 30 connecting lines for each A processor and the assignment of the remaining functions for the B processor, possibly for a different number of connections. However, the coupling element control could alternatively also be assigned to the A processor.

13 shows time diagrams for the mode of operation of a coupling element 300. Fig. 13 (a) shows for the line 302 the consecutive time element numbers and channel numbers, with 16 time elements forming a channel;

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The time element numbers are given in hexadecimal notation and only channels 0, 1 and eight time elements of channel 2 are shown.

Fig. 13 (b) shows the 4096 Mb / s multi-line clock.

Figure 13 (c) shows the frame synchronization, which is a gate synchronization command that occurs on the multiple line 302 in channel 31, time element E.

13 (d) to 13 (h) shows the time intervals of the transmission actions of these gates on the multiple line 302 for the gates 0, 1, 2, 14 and 15 of the coupling element 300. This is not shown for the gates 3 to 13, however they functionally match. Each of the bus transmission intervals 501, 502, 503, 504 and 505 of gates 0, 1, 2, 14 and 15, respectively, overlaps with the other time intervals. Each of these time intervals comprises 4 time elements P, D, W, R, wherein certain actions occur on certain lines of the multiple line 302 during certain time intervals, so that only one port can transmit information on any line of the multiple line 302 at a given moment. The exact time for the start of a transmission interval is determined by the individual gate address code word.

14 (a) shows the clock frequency according to FIG. 13 (b) again. 14 (b) to 14 (e) show the time elements P, D, W and R of the bus transmission intervals 501, 502, 503, 504 and 505 with an extended time axis.

The bus line 302 consists of 36 single-directioned wires to enable information to be transmitted between all 16 gates of a coupling element, as shown in FIG. 15. The signals given by the module's receive logic 304 to the bus 302 consist of the following: DATA (16 bits each on a separate line) TARGET-GATE ADDRESS (4 bits each on a separate line), TARGET CHANNEL ADDRESS (5 bits each on a separate line), CORRECT DATA (1 bit), CHOICE (1 bit) and MODULE (1 bit). The signals received by the multiple line 302 are: SELECTED CHANNEL (5 bits each on a separate line), CONFIRMATION (1 bit) and MODULE BUSY (1 bit). Depending on the data word of the buffer memory 402 and the content of the reception control memory 404, which is controlled by the channel number output of the buffer memory 402, various signals are sent to and accepted by the multiple line 302, and in addition different words are inserted into the gate in the case of the controlled gate , Channel and receive control memory of receive logic 304 is written. The WRITE-COMMAND line of the multi-line 302 is a special function line that can be used to enforce the performance of a particular function.

In the time element P, shown in FIG. 14 (b) with the value (1), the reception logic 304 which has just been activated transmits the destination port number to the multiple line 302 and, at the same time, the corresponding characters to the DATA CORRECT SELECTION, MODE and MODULE lines BUSY. With the rising edge of the clock pulse marked with the number (2) in FIG. 14 (1), all transmission logic switches

646 828

lines 306 of all 16 ports, the states on the aforementioned bus lines in registers associated with decoder port number circuit 420 and transmit controller 424. During the time element D identified by the number (3) in FIG. 14 (c), the reception logic of the controlled gate transmits information to the DATA lines and to the TARGET CHANNEL ADDRESS SEN lines. On the next rising edge of the clock, indicated by (4) in FIG. 14 (a), this information is transferred to buffer registers which are assigned to the data memory 422. During the time element W denoted by (5) in FIG. 14 (d), a process occurs in the gate transmission logic when the gate number identified by the 4 bits on the DESTINATION GATE ADDRESS line occurs during the time element P. , corresponds to the gate identifier code word of a specific gate, this code word being different for each gate. Said process can be a write process to the data memory 422 of this port, or a response to a SELECT command. Likewise, during time element W, a suitable value for a selected channel number is transmitted from free selection circuit 414 to the lines for the selected channel number, and a value (either 1 or 0) for an acknowledgment signal is developed. The non-confirmation consists of the absence of a confirmation signal.

In the time element R denoted by (6) in FIG. 14 (e), the destination gate transmission logic gives a response to the lines for the selected channel number and the confirmation. The activated receive logic transfers the state of these lines at the next rising edge of the clock, designated by (7) in FIG. 14 (a), into a register belonging to the receive controller 406, and brings in the subsequent, in FIG. 14 (e) with ( 8) marked time interval to update their own gate channel and receive control memories 510, 408 and 406.

The blocked channel numbers received by a blocking receiver 416 in the reception logic of a specific gate cause a rejection bit to be written in the transmission logic of the same gate at the address identified by the blocked channel number, e.g. a lock sign in channel 16 can be decoded as "lock channel 7". The next time the receiving logic that builds a path in channel 7 tries to write into channel 7, it receives no confirmation character and will designate the channel with the path in channel 7 as blocked. The lock character search circuit 418 will then output in channel 6 the number of the locked channel from its transmit logic.

The delay through the switching network is automatically reduced to a minimum by using the free selection circuit for a first free channel. The first free channel free selection circuit 414 constantly searches the occupancy bit of the transmit control memory 424 for free channels with the lowest channel number, which is higher than the pending output channel number, which supplies the serial data on the PCM line 310.

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11 sheets of drawings

Claims (17)

646 828 2nd PATENT CLAIMS 1. Telecommunication switching system with a switching network and multiple switching elements arranged therein for the optional establishment of connections between connections forming message paths, with distributed processors 5 for control functions, characterized in that - That the telecommunication switching system contains a number of connection units (12, 14, 16, ...), each of which is intended for a fixed number of lines or bundles of lines (36), and with a coupling network (10) menwork, which coupling network can be modularly expanded depending on the number of connected units (12, 14, 16, ...) as well as on the traffic to be processed (Fig. 2), - That the processors (Ao, Bo) are separated from the coupling network (10) 15 and are permanently assigned to the connection units (12), - That the processors can be connected 20 to the message paths (38) of the connection units (12) assigned to them - That the message paths (38) in addition to their function of message transmission between the connections also those of the message transmission between the processors (Ao, Bo), and - That the processors (Ao, Bo) of each connection unit 25 (12) can be connected via the communication paths (38) to all switching devices (42, 108) within the connection units (12) and in the switching network (10) and control them. 2. System according to claim 1, characterized in that the connections are combined in groups to form connection bundles (36) 30, that each connection bundle is assigned a first processor (Ao) from a first group (A) of processors, which connection-specific for these connection bundles, carries out the monitoring of connection request functions and a first part of control functions for connections containing the route search 35, that one or more connection bundles is assigned a second processor (Bo) from a second group (B) of processors, which carries out the rest of the 40 control functions for connections, which include the establishment, maintenance and triggering, that the connection between the processors of these two groups (A, B) for the establishment of a certain message connection each only exist briefly for the transmission of control information 45 containing the result of the route search, and that the processors in the two groups (A, B) are otherwise independent of one another. 3. System according to claim 1 or 2, characterized in that the message paths consist of time multiple lines on which both the messages and the 50 control information are digitized in time channels. 4. Installation according to claim 3, characterized in that the communication paths represent bidirectional connections. 55 5. Plant according to one of claims 1 to 4, characterized in that control signals are transmitted bit-asynchronously. 6. Installation according to one of claims 3 to 5, characterized in that the data to be transmitted are transmitted on PCM-coded 60 message paths. 7. Installation according to one of claims 2 to 6, characterized in that the processors of the second group (B) are also available for functions which relate to and complement those of the first group (A) of processors. 65 8. System according to one of claims 2 to 7, characterized in that said processors of the second group (B) each consist of a pair of processors for security reasons, which can be selected by the message path related selection control signals, so that when an error occurs one of processors replaced the other. 9. System according to one of claims 2 to 8, characterized in that the second group (B) of processors can be used as a call converter for the respectively assigned group of connection units. 10. System according to claim 1, with a plurality of switching stages of multiple coupling elements (300) in the switching network, from which elements all switching stages of the switching network (10) are formed and which act as multi-directional switches, and via which connections between connection units are established which are connected to the switching network are connected in dependence on selection control signals supplied to the switching elements and wherein a control device, which is assigned to the switching elements, sets up the communication paths through the switching network in order to establish desired connections and to receive data from connection units connected to these communication paths, characterized in that the data of the line units (12, 14, 16) contain control signals of existing or existing communication links, and the selection control signals which control the establishment of connections are transmitted together on the same message paths in time division multiplex that each of the coupling elements at each stage of the coupling network (10) is assigned an arrangement that transmits the data to the coupling elements bit-asynchronously via the message paths mentioned, and that this transmission takes place in such a way that the data in each of the coupling elements to which they are transmitted , are synchronized again and that each of the connection units (12, 14, 16) mentioned can be connected to any other connection unit (12, 14, 16) via communication paths. 11. Plant according to claim 1, characterized in that it contains a number of levels with several levels of coupling elements (300), at least some of these levels (100, 106) being connected via multiplex transmission paths to access switches (42, 44) in the connection units (12). 12. Installation according to one of claims 10 or 11, characterized in that means are provided which bring about a reflection of the transmission signals by the coupling network in the last stage of the switching network, only a single constant data address being required for such a reflected transmitted signal. 13. System according to one of claims 10 to 12, characterized in that means are provided on each of the coupling elements (300) which can receive and evaluate the digital data commands transmitted via the message channels which relate to the establishment of the connection. 14. System according to claim 10, characterized in that each multiple coupling element (300) has a plurality of gates (304, 306) and a bus line (302) which is designed as a time-division multiplex transmission path containing a plurality of channels, and in that connections are established by means of digital command signals for asynchronous data can be switched from one gate as an input to another gate as an output via the bus. 15. System according to claim 14, characterized in that means are provided at each gate for a synchronous transmission of the data from an entrance gate to the bus and means for receiving command signals, which can selectively remove data from the bus, based on these commands data be transmitted from the bus to an exit gate. 16. Plant according to one of claims 14 or 15, 3rd 646 828 characterized in that, depending on the command signals supplied to it, the multiple coupling element either selectively reflects the data traffic arriving via an entrance gate, the reflection occurring at an exit gate, or the entrance gate at which the connection signal 5 arrives is also represented as an exit gate, the Data traffic is then coupled in phase synchronization from the entrance gate to the exit gate. 17. Installation according to one of claims 14 to 16, characterized in that the multiple coupling element for 10 contains the input or readout into or out of a gate, which contain a reception control logic (308) for the bit and word synchronization, and that transmit control logic (306) is included for the bit-synchronous transmission of data from the bus serially through the port. 15