MXPA96005964A - Tres eta switching unit - Google Patents

Abstract

The present invention relates to a three-stage switch unit, comprising a number of incoming drivers related in groups, each group is connected to a first switching stage, formed as an input circuit, a number of outgoing drivers related in groups each group is connected to a second switching stage, formed as an output circuit, a third switching stage, related and which can be connected between the input and output switching stages, which operate as an input circuit and an output circuit, whereby the incoming conductors and the outgoing conductors are adapted to transfer electrical signals carrying information, and a control unit, which acts in conjunction with the switching stages, in order to connect one of the incoming conductors with a selected outgoing conductor, by means of a connection path, which indicates through and enters the third stage d and related switching, whereby each and all the outgoing conductors, belonging to the first switching stage, act in conjunction with an electro-optical converter, and the respective connection between the first switching stage and the third switching stage they consist of an optical conductor, whereby the third switching stage is adapted to transfer optical signals carrying information through the connection path, and the connections between the third switching stage and the second switching stage consist of optical conductors and conductors entrants, which belong to the second switching stage, are previously connected by the opto-electric converters characterized in that the first switching stage consists of a number of switching units, each and all adapted to present the same number or number of conductors Outgoing, the second stage of commutation consists of a number of switching units, each and all have the same number of incoming conductors, the third stage of commutation, consists of a number of commutation units, each and all have the same number of incoming conductors as outgoing conductors and because the The number of outgoing conductors of a switching unit, within the first switching stage, is selected to correspond to the number of switching units within the third switching stage.

Description

THREE-STAGE SWITCHING UNIT TECHNICAL FIELD The present invention relates to a switching unit or three-stage switching structure and, more particularly, to such a three-stage switching unit, comprising a number of related conductors of incoming groups, connected to a switching stage. of input or a first switching stage, a number of outgoing conductors, connected to an output switching stage, or a second switching stage, and an intermediate stage, between the related switching stages, or a third switching stage, which relates and can be connected between the first and second switching stages, such as an input circuit operation and an output circuit operation, The present invention is further based on such a three-stage switching unit, where the incoming conductors and outgoing conductors are adapted to transfer electrical signals that carry information and where the co ntrol acts in conjunction with the switching stages, in order to connect one of the input conductors with a selected output conductor, by means of a connection path, points through and between the related switching stages.

These input circuits are to present the output conductors, equipped with electro-optical converters, in order to be able to transmit optical pulses, which correspond to an electric current signal carrying information, to and between the related switching stage and the output circuits present the input conductors, equipped with opto-electric converters, in order to receive optical pulses from and between the related switching stage, which corresponds to the signal carrying information, which belongs to a current input circuit . Switching units or switching structures belong to this class, with the three switching stages also denoted as a first, second or third switching stage, in a consecutive order, and keeping in mind this it should be noted that the The second switching stage corresponds to the one denoted as the third switching stage and the third switching stage corresponds to the one denoted here as the second switching stage. It will be obvious to one skilled in the art that the switching units can be handled as a two-way communication, independently of the information flow, but in order to simplify the following description, only one selected address will be described independently of the Information flow.

DESCRIPTION OF THE PREVIOUS TECHNIQUE The multistage switching, which belongs to the class described above, is previously known in a number of various modes and the rules of the main construction and dimensions, which relate to a switching unit of Three stages, non-blocking, are shown and described in more detail in the publication "ISDN and Broadband ISDN", under section 2: 3"Space-Division Switching" and specifically on page 33, with reference to Figure 2.8. The main construction of a three-stage switching unit is described above and is dimensioned to be able to supply a non-blocking signal transmission in a passage of incoming connections. The structure using a first, second and third switching stages is not supplied in detail. However, it is known to form the switching stages so that they adapt to pass the digitalized electrical signals that carry information, whereby the electrical conductors are related to each other and structured in accordance with the pattern indicated by the publication. . Taking into consideration the significant characteristics of the present invention, it can also be mentioned that previously it is known to be able to receive electrical signals that carry information and, through the electro-optical converters., converting these optical pulses of light and transmitting them on an optical conductor to an opto-electric converter, which receives the optical pulses and transmits the corresponding electrical signals which are in-formation. Such optical information carrying systems have been used within various electrotechnical applications, such as large switching units, in order to transmit signals carrying information over longer distances, such as between different cubicles or the like. Taking the significant characteristics and thus the significant measures of the present invention under further considerations, it can be mentioned that the totally optical switching units are known and described previously through the publication "Technical Digest of Conference on Optical Fiber Communication", in the article "Feasibility demonstration of 2.5 Gbit / s 16x15 ATM photonic switching matrix", on pages 93 to 94, by the authors D. Chiaroni et al, and the publication "Proc. Topical Meeting on Optical Amplifiers and their Applications, postdeadline paper ", 1992, in the article" Monolithically integrated 4x4 InGaAsp / Inp laser amplifier gate switch arrays ". on pages 38 to 42, by the authors M. Gustafsson et al. In the mentioned publications, the use of controllable optical switching components, such as optical switching matrices, is described, whereby the optical light pulses, which appear in one of a number of optical input leads, related to available groups , can be selected and switched through a core to one of several selected, available optical output leads. In order to simplify the understanding of the features of the present invention, reference may be made to the publication "Proc. European Conference on Optical Communication", 1990, with the article "Characterization of a 1.5 m three-electrode DFB laser", on pages 279 to 282, by the authors RJS Pedersen et al, where a transmitter related to a tunable laser is described. A receiver in an application related to lasers, is described in the publication "Proc. European Conference on Optical Communication", 1991, with the article "Performance of DBR active filters in 2.5 Gb / s systems", on pages 445 to 448 , by the authors 0. Sahlen et al. The principles of the transmitter and receiver can be used within the present invention. What is shown and described in the following publication is also part of the related technique. "Wavelenght Laser Conversion Diodes Application to avelenght-Division Photonic Cross, Connect Node with Multistage Configuration", H. Rokugawa et al IEICE Trans. on Communication, Vol. 575-B, No. 4, April 1992, pages 267-274. A three-stage switching structure or unit is, through this publication, previously known with a construction principle that matches the basic conditions of the present invention. It has been indicated (according to Figure 1) the use of an opto-electric signal conversion stage (O / E), an attempted stage for the electrical signal processing (ESP), a stage of electro-signal conversion. optical (E / O), a switching stage, adapted for optical signals (OSP), a stage of conversion of opto-electric signals (O / E), an attempted stage to process electrical signals (ESP) and a stage of conversion of electro-optical signals (E / O). A connection arrangement for the switching stage (OSP) is described mainly with reference to Figure 2, which is specifically adapted to a wavelength separation, so that signals with different wavelengths can simultaneously pass to each other. Through a single optical fiber and the conditions to increase the flexibility and capacity of such optical communications network has already been created.

It can be specifically mentioned that the switching stages used here are dimensioned for one and the same capacity and that the optical switching stage (OSP) is dimensioned and adapted to the stages O / E and E / 0. The switching unit is dimensioned and thus adapted to a selected capacity and the possibilities to a gradual extension are not indicated or mentioned. It would be made clearer, through which it is described in Figure 2, that all the outputs are connected to all the inputs through the optical stage used. In addition to these described possibilities, to allow a selected wavelength from each selected source (1.1 - ln) to an incoming block, be mixed before with an optical signal, with several wavelengths (? >? -? 'N) being transmitted through an exit blog. A separation of wavelengths is thus realized with a number of possible receivers. A reguisito in a optical unit of commutation of this class is that the intensity selected of the light of the signals that take information, that appear in one of the entrances must be sufficiently high to be sufficient for all the exits. "Trend of Photonic Switching Systems" S. Suzuki et al. IEICE, Trans. on Communication, Vol. E75-B, No. 4, April 1992, pages 235-242.

A number of switching units are described here, which are intended to be able to transmit broadband signals. The switching structure, according to Figure 15, can be considered of some importance. We describe a switching equipment, adapted to ATM cells, where these ATM cells are tried to pass through them, and connect or a multi-channel unit (MUX S / P), which restructures the related ATM cells, Parallel, incoming, to an ATM cell structure connected in series, in a single conductor and these ATM cells connected in series, can be stored within a memory. Each ATM cell, regardless of the bandwidth required, will now pass through an OSM optical matrix connection, which requires a high speed, which means that a speed corresponding to the ATM technology is here required through the complete system of Connection. A control of the OSM stage is required, so, for each ATM cell, which passes through the OSM stage, a selected input connection can be connected to a selected output connection. COMPENDIUM OF THE INVENTION Taking into consideration the prior art, described above, it is considered as a technical problem the ability to create a three-stage switching unit, with a first, a second and a third stage, of the class previously described. , and where the input conductors and the output conductors are adapted to transfer electrical digitized signals that carry information with high speed, under the conditions between the related switching stages or the third switching stage, a glue space is regulated and simple, and thus carry out a solution in the respective switching stage of the structure in a number of switching units or switching components. In addition to this, it should be considered as a technical problem to be able to realize the importance of selecting a number of output connections of each switching unit, within the first switching stage, to correspond with the number of switching units within the third stage of commutation. It is thus a technical problem to be able to realize the importance of permitting, and the advantages obtained from, each switching unit, within the third switching stage, to be supplied with the same number of input connections as output connections. In addition to this, it is necessary, with respect to a technical problem, to be able to carry out the simplifications which are provided as the switching units from among the related switching stages., they can be allowed to be totally optical, with respect to the reception, direction and transmission of the digitalized signals that carry information, without the need for any signal to be conveyed in the transmission of electrically related information. There is a technical problem in the ability to make savings in the switching structure and that can be done by allowing each optical output conductor, which belongs to an optical switching unit, to be supplied with an optical signal distribution unit, a unit that divides an optical signal into two equivalent parts (optical division), where the output conductors of the unit, which transfer the same optical pulses, can thus be connected to an input connection or opto-electric converter in each switching unit , within the second switching stage. It can also be considered as a technical problem, with the three-stage switching unit, of the kind described above, being able to realize the importance of, and the conditions required to, allow each switching unit, within the related switching stage. , is arranged to be able to receive optical signals directly from each and all the number of groups related to the optical input drivers and to be able directly to connect the optical impulses that appear in an input conductor, by means of a signal from control generated by a control unit, to one of the various selected, available optical output conductors, and thus the control unit will generate control signals, adapted to use the switching units within the first and second switching stages. It should also be considered as a technical problem to be able to realize the advantages that are obtained, within the three-stage switching unit, that each optical pulse of each switching unit may be allowed, within the third switching stage, can pass as an optical impulse transmitted, without the need for, for these purposes, amplifier circuits for optical pulses. It should also be considered as a technical problem, to be able to realize the advantages that can be provided by a three-stage switching unit, as input and output conductors, intended for use in electrical signals, that transfer groups related to electrical signals They carry information, structured in data packets, specifically as ATM cells. There is a technical problem of being able to realize the advantages that are obtained as several data packets, for example two, given different directions, can be transferred in the same optical conductor and adapt a circuit that evaluates an address, belonging to a receiver, to decide which of the related management packages to take care of and which to discard and thus provide the use of an optical conductor to transfer two additional separate digitized signals, which carry information It should also be considered as a technical problem to be able to perform and how to read a unit Three-stage switching can provide a reliable safety function and adaptation, even when the switching units within the first switching stage, structured as an input circuit, adapt to a total maximum bit rate of more than 50 Gb / s, and specifically more than 80 Gb / s. It should also be considered as a technical problem to be able to realize the advantages obtained by using a control unit, which is arranged to activate a connection path, between a selected input circuit and a selected output circuit, through one of the switching units, within the third switching stage, which comply with the required bandwidth, depending on this bandwidth required of a connection currently needed by a caller and taking into consideration the selection of one or more lengths cool. It is also a technical problem, being able to realize the importance of the simplifications that can be expected, allowing the control unit to control a selected unit of wavelength, belonging to each electro-optical converter of each output conductor, from the switching units, within of the first switching stage, so that the control unit, through the circuit, can select to transmit optical pulses with a first frequency or wavelength or to adapt to transmit optical pulses of another frequency or wavelength , and at the same time be able to create the conditions that are required to activate the reception circuits, which belong to one or more incoming conductors of the output circuits in the switching units, through the control unit, and thus provide the use of an optical conductor for the transmission of two separate digitalized signals that carry information. SOLUTIONS With the intention of solving one or more of the technical problems mentioned above, the present invention is based on a three-stage switching unit, or switching structure, comprised of a number of related con-ductors of incoming groups, connected to a first switching stage, formed as an input circuit, a number of conductors related to outgoing groups, connected to second switching stages, formed as an output circuit, a switching stage, related and that can be connected between the con-mutation stages that operate an input circuit and an output circuit, whereby the incoming conductors, the outgoing conductors and the first and second switching stages, are adapted to transfer electrical digitized signals carrying information and the first and second switching stages, they adapt to allow an electrical signal carrying information, which ap If you find yourself in an incoming driver, pass an outgoing driver selected by a control unit and said control unit. The present invention uses a control unit arranged, in a known manner, to act in conjunction with, and control the connection paths within, the switching stages, in order to connect one of the incoming conductors, which belong to the first con-mutation stage, through this first switching stage, between the related switching stage and the second switching stage, with a selected outgoing conductor, which belongs to this second switching stage. The invention in principle is based on the fact that the first switching stage is divided into a number of switching units or switching components, which each and all the outgoing conductors, belonging to the respective switching unit, act in conjunction with the electro-optical converter, which belongs to, or supplied to, the driver, that the respective connection between the respective first switching stage and the third respective switching stage can thus consist of optical conductors, that the third switching stage is divided into a number of switching stages, each and all adapted to transfer the light pulses, which carry information, optically totally, than the connections between the respective switching units within the third switching stage and the respective switching units within the second switching stage, consist of optical conductors and that the incoming conductors, belonging to the second switching stage, are previously connected by opto-electric converters. As proposed modalities, which are within the scope of the invention, it is indicated that each output connection of a switching unit, within the first switching stage, is connected to each input connection, which belongs to a unit of switching within the third switching stage. The number of input connections and output connections of each switching unit, within the third switching stage, it is selected to be the same. It is further indicated that the switching units within the first switching stage, the second switching stage and / or the third switching stage, are structured as a switching matrix or alternatively that the switching units are structured as units Three-stage switching. It is further indicated that the respective protruding optical conductor, which belongs to the switching units, within the third switching stage, is equipped with a distribution unit, intended to separate optical signals, where the outgoing conductor of the switching unit. Distribution, which corresponds to the outgoing conductor of the switching unit, is connected to the incoming conductor of the respective opto-electric converter of the respective switching unit, within the second switching stage. It is specifically indicated that each and all the outgoing conductors belonging to the first switching stage act in conjunction with an electro-optical converter, and that the outgoing optical conductor, coordinated with the respective electro-optical converter, is connected to a connection input of one of the switching units, within the third switching stage. The number of outgoing optical conductors, from each switching unit, within the first switching stage, is selected to correspond to the number of switching units within the third switching stage and these optical conductors are arranged between the output connections of a selected switching unit and an input of each and all switching units within the third switching stage. With such a three-stage switching unit, adapted to receive and pass electrical signals that carry in- formation, it is indicated by the present invention that each switching unit within and between the third related switching stage, is arranged to be capable of directly receiving optical signals, which appear in each and all of a number of groups related to the incoming optical conductors, and to be able to directly pass optical pulses that appear in an incoming conductor, by means of a control signal generated by the control unit, to one of the several selected outgoing optical conductors, available. As proposed embodiments, within the scope of the invention, it is further indicated that each optical pulse, received by one of the switching units, within the third switching stage, is capable of passing as an optical transmission pulse, to through an output selected from and between the related switching unit. Likewise, it is indicated that the incoming and outgoing conductors transfer groups related to the electrical signals that carry information, structured in data packets, specifically as ATM cells.

The present invention furthermore states that the switching units within the first switching stage, structured as an input circuit, are adapted for a reception of a total maximum bit rate of at least greater than 50 Gb / s. Furthermore, it is indicated that, through the control unit, there is each electro-ottic converter, which belongs to an input circuit, adapted and controlled to transmit optical pulses with a first wavelength and another input circuit can be adapted for transmit optical impulses of another wavelength. ADVANTAGES The advantages that can primarily be considered as characteristics for a three-stage switching unit, with the switching stages formed by a number of switching units, according to the present invention, are, according to the present, that have been created conditions for supplying a three-stage switching unit, with a simplified mode, where the simplifications lie partly within the control unit and partially within the use of a fully optical stage, between the related switching stage, formed by a number of switching units, which provides the possibility of using a simple auxiliary equipment in comparison with the electrical switching stages, and which can also supply simplifications obtained from the wavelength multichannel and / or the multiple addresses of data packets by the use of a unit for each outgoing optical conductor, which distributes optical pulses to the two conductors.

The primary characteristics of a three-stage switching unit, according to the present invention, are indicated in the characterizing clause of the following Claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS A currently proposed mode of a three-stage switching unit, according to the present invention, will now be described in more detail with reference to the accompanying drawings, in which: Figure 1 shows a previously known construction, in principle, of a three-stage, non-blocking switching unit, whose principle is also used in this more detailed description of one embodiment of the invention; Figure 2 shows a blog diagram of a three-stage switching unit, which is significant in the present invention; Figure 3 shows a simplified diagram of the wiring of a switching unit, according to Figure 2, with the use of connections or optical conductors, where the light pulses of various wavelengths appear for the optical pulses carrying information; Figure 4 shows the beginning of a first switching stage with an electro-optical converter, supplied to the respective outgoing conductor; Figure 5 shows the principle of a third switching stage, in the form of a matrix, with a unit distributing optical signals to two conductors, supplied to the respective outgoing conductor; and Figure 6 shows, in principle, a blog diagram, of a control unit, for the control of a connection of a regulated connection path. DESCRIPTION OF CURRENTLY PREFERRED MODALITIES In general, a three-stage, non-blogging switching unit l is thus shown with reference to Figure 1. Such a three-stage switching unit, in principle, is obtained from three switching stages, a first switching stage 3, a second switching stage 5 and between them related or intermediate switching stages 6, with a number of switching units or switching components. The training of the individual switching stages will be obtained according to the publication, already mentioned at the beginning of the description, in order to obtain a non-blogging switching unit, which means that each arrival cell, accepted for the passage , is able to be connected through the switching unit without internal blogging functions. The modality, according to Figure 2, shows a three-stage switching unit, according to the invention, which comprises a number of incoming conductors 2, where some conductors 2a are in grouped relation and are connected to the inputs of one of several 3a switching units available, formed as input circuits. The illustrated embodiment shows that ten and six (16) identical switching units 3a-3m, can be used distributed over the number of incoming conductors 2a, each and all adapted to a maximum bit stream of 80 Gb / s. Some conductors 4a, of the total number of outgoing conductors 4, are in grouped relation and can be connected to the outputs of one of several available switching units 5a-5m, as part of the second switching stage 5 and are formed as output circuits. The outgoing conductors 4a of each second switching stage 5 can be adapted to a total maximum current of 80 Gb / s, distributed over the number of connected outgoing conductors 4a.

Also between the related switching units 6a-6n, forming the third switching stage 6, which can be connected between the switching stages 3 and 5 and their switching units 3a-3m and 5a-5m, respectively, operating as input circuits and output circuits. A more detailed description of the required and main construction of the switching stages 3, 5 and 6 is not necessary, since it is previously known. However, it will be mentioned that the switching units within the switching stages 3 and 5, are of a construction that provides the possibility of allowing the signals related to the electrical impulses, which carry electrical information, to pass, while the units of switching within the switching stage 6 are of a construction that will allow the passage of the totally optical light pulses, which carry optical information. The switching unit 1, according to Figure 2, is hereby structured so that each information appearing in one of the incoming conductors 2a, for example the conductor 2a ', can pass through a selected outgoing conductor. , one of several available 3a, for example the conductor 3a », by means of the structure of the first switching stage 3, the switching stage 3a, inside and through a received control signal, generated by a control unit 10 In the same way, other information appearing in the other of the incoming conductors, for example the conductor 2a ", may be passed to a selected outgoing conductor, one of the several available 3a, for example the conductor 3b ', by means of the structure of the first switching stage 3, the switching stage 3a within and through a received control signal, generated by a control unit 10. It is of certain importance that each outgoing conductor, such as the conductor 3a1, is connected to an electro-optical converter 41, supplied by the driver Each electro-optical converter of each outgoing conductor is coordinated with a unit 32. The conductor 3a 'is thus, through its electro-optical converter, which is connected to an optical conductor 3a ", in connection with an input connection of a switching unit 6a, within the third switching stage, an adjacent conductor 3b1 is, through its converter ctro-optical 42, which is connected to an optical conductor 3b ", in connection with an input connection of a switching unit 6b, within the third switching stage, and etc., in the" n "switching units. From this, it is clear that each switching unit 3a-3m, within the first switching stage 3, has a number of outgoing conductors and electro-optical converters, corresponding to the number of switching units, 6a-6n, within the third switching stages 6. The first protruding optical conductor 3a "is connected to a first input connection of the switching unit 6a, a second protruding optical conductor 3b", is connected to a first input connection of the switching unit 6b, etc., up to the n outgoing conductor, which is connected to the switching unit 6n. The first outgoing conductor 3m "of the last switching unit 3m is connected to the last input connection of the switching unit 6a, etc. The number of outgoing conductors of each switching unit, 3a-3m, within the first switching stage 3, corresponds to the number of switching units 6a-6n, within the third switching stage 6 and the number of input connections in each switching unit, within the third switching stage, corresponds to the number of units of switching, 3a-3m, within the first switching stage 3. The number of switching units, within the first switching stage 3, is ten and six and the number of switching units within the third stages of switching. commutation is thirty-two.

Each input connection 51a of the switching unit 6a, within the third switching stage 6, can be connected to one of the sixteen input connections, through the control unit 10, in order to establish a connection path through this switching unit 6a. The main construction of the switching unit within the third switching stage, such as the switching unit 6a, is illustrated in Figure 5. This switching unit 6a is a matrix related to four selector optical elements, 51, 52 , 53, 54, and each previously known. The switching unit 6a has two related group elements, 51 and 53, eguided with eight optical input conductors, one of which is denoted 51a, and which may correspond to the optical conductor 3a. "The switching unit 6a presents the elements, 52 and 54, related to each other, each having eight optical output conductors, one of which is designated 52a and which may correspond to the optical conductor 6a ". Each and all of these sixteen conductors act in conjunction with a light distributor, of which one has been denoted by 521, and which distributes incoming light pulses to two related light pulses, parallel, one appearing on the 6th conductor "and another in the conductor (6a") and thus thirty-two outgoing conductors are supplied, each and all connected to one of the thirty-two opto-electric converters, which belong to the sixteen switching units inside. of the second switching stage 5. The conductor 6a "can be connected to the switching unit 6a and the conductor (6a") can be connected to another switching unit, such as 5m. Figure 5 is intended to illustrate that each outgoing optical conductor is equipped with the light distributor, such as 521-528 and 541-548. Each and all sixteen switching units, 5a-5m, have sixty-four conductors, with an opto-electric converter each (not shown). The arrangement and advantages of using the optical light distributors, 521-528 and 541-548, will be described in more detail in the following. The switching units 5a-5m consist of, in the same manner as described with reference to Figure 4, a number of opto-electrical converters previously connected, within the circuit 70, with a converter for each optical conductor and connection of entry. The optical conductor 6a "can thus be connected to an opto-electric converter, oriented inside the circuit 70, whose electrical signals appear in the conductor 6a 'and then in the conductor 4a' .The invention is given a specifically suitable application if the incoming conductors 2 and the outgoing conductors 4 are adapted to transmit electrical signals carrying information, in the form of current or voltage pulses, coordinated in data packets, which, in the embodiment, are supported to consist of ATM cells. One embodiment is thus illustrated with reference to Figure 3, where selected connection paths, through optical conductors, such as 6a ", can be used for several signals, of" double "use through the selection of the length of wave used for light pulses. For these purposes, it is reguired that, according to Figure 3, the wavelength selector of the outgoing conductor, for example 3a ", is controlled through the control unit 10, so that the respective electro-optical converter is adapted to transmit the optical pulses with a first wavelength or the optical pulses with a second wavelength in the conductor If it is assumed that the first wavelength is used in the optical conductor 32 'and the second length of wave in the optical conductor 32", then the input connections of the switching unit 6a, which belongs to these conductors, are connected to each other, to form a single conductor in which the signals with multichannel wavelength appear and a The receiver, 37 or 38, selective wavelength, through the control unit 10, will be activated to select the selected wavelength to an input circuit of the switching stage 5. It will be seen that in one of the output drivers 6a "of the switching unit 6a, there will be light pulses with two separate wavelengths, which can be separated from each other, in a controlled manner, before the second switching unit.The receiver circuits, 37, 38, of the optical pulses, which belong to one or more output circuits, through the control unit 10, can be controlled to receive optical pulses carrying information, with a selected wavelength and to arrange the pulses with another wavelength This technology will not be described later, since the ATM technology is well known, where the data palets are structured as ATM cells with a part relative to the address, the "Header", and a part that carries information, the "Payload." However, it will be mentioned that switching stages 3, 5 and 6 are controlled by a control unit 10 in a manner which, by itself, is very complex.

The following description is intended only to describe the parts of the control unit 10 which are re-guided to understand the function of the present invention. The application of the invention with a paging data network and, more specifically, an ATM system, will now be described in more detail with further reference to Figure 2. A control unit 10 is illustrated schematically in Figure 2 and functions as is described in more detail in Figure 6. The control unit 10 acts in conjunction with the switching stages 3 and 5 in order to control the switching units within them and connect one of the incoming conductors 2a 'to a 4a * selected conductor, through one of the relational switching units, so that each data cell (ATM cell) appearing in series in conductor 2a "can pass through it. several of them, presents a part 21 related to the address and a part 22 related to the information.In a call, the calling party needs an activation of the switching unit, since an ATM erida presents, in its part 21 related to the address, a channel number, which indicates a call and through the part 22 carrying information, presents the bandwidth required for the desired connected connection.

The ATM cell then supplies the information in which part called the connection is going to be made. The control unit is arranged to be able to activate a connection path, between a selected input circuit 3 and a selected output circuit 5, which belongs to the related switching unit, which corresponds to the currently required bandwidth. (See Figure 6). The electrical impulses that carry information, which appear in the conductor 2a ', are detected and interpreted by means belonging to the control unit 10, an element 101 that is intended to indicate a call, an element 102 in order to establish the bandwidth desired and required and an element 103 to indicate the part currently called (caller B). A central unit 110 evaluates in a memory 104 whether the required bandwidth can be received by the caller B in question. All available connection paths, through the switching units 6a-6n, and the instantaneous coupling of each and all of them, are stored within the memory 104. It is evaluated simultaneously if the caller B can receive the selected connection. The caller B is coupled if the evaluation is negative, which is indicated to the party that calls, the caller A, through a circuit 106. If the evaluation is positive and since, according to the basic conditions of the structure of the switching unit, there can be some internal blogging, then caller B is available and caller A is notified, through circuit 107, that the call is accepted with the selected bandwidth. The possibilities of coupling the optical connection path, already connected, from the switching stage 3 to 5, through one of the switching units 6a -6n, within the third switching stage and with a regulated bandwidth, it is evaluated through the central unit 110 and a calculation circuit 111. The selected connection path is labeled as coupled within the memory 104 s there is a positive result of the calculation. A new calculation circuit 112 is activated if there is a negative result. This circuit 112 evaluates the possibilities of using any of the optical connection paths established in a "double" manner, such as between a first switching stage and a third switching stage, such as the conductor 3a ", or between a third switching stage and a second switching stage.

Such double use can be achieved through the use of optical distributors 521-528, 541-549. One and the same opto-electric converter receives the ATM cells with separate addresses and only the ATM cells with the selected address are allowed to pass while the rest is discarded. Another opto-electric converter receives the same ATM cell current, but only ATM cells with an address belonging to the converter are allowed to pass, while the rest is discarded. The selected connection path is labeled as coupled within the memory 104, if there is a positive result of the calculation. A new calculation circuit 113 is activated when there is a negative result. This circuit 113 evaluates the possibilities of using any of the established paths of optical connection in a "double" manner, such as between a first switching stage and a third switching stage, such as the conductor 3a ", or between a third stage of commutation and a second step of switching over multiple wavelengths, described in more detail with reference to Figure 3. The selected connection path is labeled as coupled within the memory 104 if there is a positive result of the calculation.

A new optical connection path is evaluated through the central unit 110 if there is a negative result and a new calculation unit 114 is activated to signal an available optical connection. The selected connection path is labeled as coupled as soon as the central unit 110 can establish a positive result from a calculation and the call (and the caller A) is, through a circuit 108, given with a new internal channel number , which corresponds to a selected connection path, so that all ATM cells with a designated channel number can pass through the established connection path and the required information is presented to the corresponding switching stages 3, 5 and 6, which include the activation of wavelength selection or the like. The established connection path is removed from the memory 104 through a calculation circuit 109 and other information relating to the established connection path is removed when the caller A indicates, with a new ATM cell, that the call is to be disconnected. . It should be noted that the selective receivers, 37 and 38, of wavelength are previously connected to a light distributor 40.

The selection of wavelengths within 32 'and 32"and within receivers 37 and 38, is made through the control unit 10. It can also be mentioned that the address evaluation units for the ATM cells they are previously known and included in the selected switching units within switching stages 3 and 5. It will be understood that the invention is not restricted to its illustrated exemplary embodiments and that modifications can be made within the scope of the invention, illustrated in the following claims.

Claims (7)

1. CLAIMS 1. A three-stage switching unit, comprising a number of incoming conductors related in groups, each group is connected to a first switching stage, formed as an input circuit, a number of outgoing drivers related in groups, each group is connected to a second switching stage, formed as an output circuit, a third switching stage, related and which can be connected between the input and output switching stages, which operate as an input circuit and a output circuit, whereby the incoming conductors and the outgoing conductors are adapted to transfer electrical signals carrying information, and a control unit, which acts in conjunction with the con-mutation stages, in order to connect one of the incoming conductors with a selected outgoing conductor, by means of a connection path, which indicates through and between the third stage of switching relaci onate, whereby each and all the outgoing conductors, belonging to the first switching stage, act in conjunction with an electro-optical converter, and the respective connection between the first switching stage and the third switching stage consist of an optical conductor, whereby the third switching stage is adapted to transfer optical signals carrying information through the connection path, and the connections between the third switching stage and the second switching stage consist of Optical conductors and incoming conductors, which belong to the second switching stage, are previously connected by the opto-electric converters characterized in that the first switching stage consists of a number of switching units, each and all adapted to present the same number or number of outgoing conductors, the second switching stage consists of a number of units of switching, each and all have the same number of incoming conductors, the third stage of commutation, consists of a number of commutation units, each and all have the same number of incoming conductors as outgoing conductors and porgue the number of conductors projections of a switching unit, within the first switching stage, is selected to correspond to the number of switching units within the third switching stage. The three-stage switching unit, according to claim 1, characterized in that each output connection of a first switching unit, within the first switching stage, is connected to each input connection of a switching unit. , within the third stage of commutation. 3. The three-stage switching unit, according to claims 1 or 2, characterized in that the number of input connections and the number of output connections of each switching unit, within the third switching stage, are selected to correspond to the number of switching units within the first and second switching stages. The three-stage switching unit, according to claim 1, characterized in that the switching units within the first switching stage, the second switching stage and / or the third switching stage are structured as a matrix of commutation. The three-stage switching unit, according to claim 1, characterized in that the switching units within the first stage, the second stage and / or the third stage of switching, are structured as three-stage switching units. . 6. The three-stage switching unit according to any of claims 1 to 5, characterized in that the protruding optical conductors, which belong to the third switching stage, are equipped with a unit intended to separate the optical signals., where the outgoing conductors of the unit, which correspond to the outgoing conductors of the third stage, are connected to an opto-electric converter, each one of which, in turn, is connected to each input connection. of the second switching stage. The three-stage switching unit, according to claim 1, characterized in that each switching unit, within and between the third related switching stage, is arranged to be able to directly receive optical signals, which appear in each one. and all of a number of incoming optical conductors related in group, and to be able to directly pass the optical pulses that appear in an incoming conductor, by means of a control signal, generated by the control unit, in order to indicate a trajectory connection, to one of the various outgoing optical conductors selected. 3. The three-stage switching unit, according to claim 1, characterized in that the first switching stage, structured as an input circuit, is adapted to a maximum total bit rate of more than 50 Gb / s. 9. The three-stage switching unit according to claim 1, characterized in that through the control unit is an electro-optical converter, adapted to transmit optical pulses with a first wavelength and an electro-optical converter , which belongs to another, or the same, input circuit, is adapted to transmit optical pulses of another wavelength.