DE10338695A1 - Add-drop device for wavelength multiplex signals has branching device for feeding through signals to other add-drop devices, signal combiner for receiving through signals from other add-drop devices - Google Patents

Abstract

The device has a longitudinal branch (3-6) with wavelength selective element(s) (4,5), drop (9,11,12,14) and add (19,21,23-26) branches. A through path has a signal branching device (4) for feeding through signals to other add-drop devices and a signal combiner for receiving through signals from other add-drop devices. The drop branch has drop-routing elements (12,13) followed by adjustable filter elements (14,15). The add branch has add-routing elements (22,23). An independent claim is also included for the following: (a) a cross-connect device for optical signals.

Description

The The invention relates to an add-drop device for optical wavelength multiplexed signals and with several of these facilities built cross-connect facilities.

The transfer of optical signals is nowadays using wavelength division multiplexed (WDM) signals. The task of an add-drop facility is to provide individual signals (Channels) of the multiplex signal (drop) and in their place new Insert signals (Add).

Several These add-drop devices become a photonic (pure optically working) cross-connector, which allows individual signals (channels with one wavelength), here referred to as tributary signals, branch off a multiplex signal and to insert into another multiplexed signal without any prior conversion in electrical signals is required. In addition, the diverted tributary signals also converted into electrical signals and in the electrical level with lower granularity be (routed). As well after the opto-electrical conversion, the insert is also electric working 3R generators possible. Before pasting in one of the optical multiplex signals is then again an electro-optical Conversion and possibly also a wavelength conversion required, but not to be discussed here.

The known photonic add-drop devices and cross-connectors use optical splitters, optical combiners, switching matrices and wavelength-selective Elements. The problem especially with the use of splinters and 1: n switch lies in the reduction of the useful signal level. As is often even through a multiple increase in the Nutzsignalpegel required; the required optical amplifier but make the facilities consuming and expensive.

In "Journal of Lightwave Technologies", Vol. 14, No. 10, Oct. 1996, pages 2184 to 2196 various cross-connect architectures are described. 2 This article shows a schematic circuit diagram of an optical ring network whose network nodes contain both photonic cross-connectors and add-drop devices as well as combinations of photonic and digital (electrical) cross-connectors. The digital switching networks are provided for switching through signals of smaller granularity. The architectures shown in further figures include optical splitters, tunable filters, space switch arrays, and optical combiners, optionally supplemented by wavelength converters. The amplification of the signals is schematically represented by fiber amplifiers, which are upstream and downstream of the switching network.

In US Pat. No. 5,504,827 is an arrangement with a wavelength demultiplexer, programmable filters and a wavelength multiplexer, which works as an optical cross-connector. The arrangement contains discreet built-up wavelength selective Switches that enable the desired signals to be switched through.

in the US Pat. No. 6,268,952 already discloses wavelength-selective switches for a used simple optical cross-connector.

From "IEEE Photonics Technology Letters ", Vol. 15, No. 2, Feb. 2003, pages 332-334 an add-drop device is well known in the art Way over an optical coupler decouples a portion of a wavelength multiplexed signal and tunable Filter selected tributary signals. The branched signals be through an adjustable filter device in the through path suppressed.

The decoupled partial signal (and possibly also the signal carried out) will over an amplifier guided. The add branch is out of the box the obligatory amplifier provided a noise filter, which ensures that the signals carried not unnecessary through the amplifier noise impaired become.

In 1 the principle of a cross-connect device described above is shown in simplified form. The cross-connect device can be divided into different layers. One layer, the photonic cross-connector PXC interconnects only optical (photonic) signals. This layer receives and transmits wavelength division multiplexed signals and is capable of coupling or adding tributary signals (channels) of a specific wavelength via another layer, here referred to as Optical Tributary Connection OTC. These tributary signals λ _DX , λ _AX can be introduced in optical form directly via the optical tributary-Connenction to the photonic cross-connector PXC or output from this. However, the interface function Optical-Tributary-Connection between the photonic cross-connector PXC and an electrical cross-connector EXC is essential, which can output and receive the tributary signals in electrical form and divide each tributary signal into a plurality of sub-signals of smaller granularity and as can switch through digital signals. 1 thus represents a universally applicable cross-connect device.

task The invention is to provide an add-drop device that it allows, with moderate effort both optical signals on the photonic level can switch through, branch off and add. Besides that is a cross-connect facility indicate that both tributary signals photonic and digital switch through electrical signals with smaller granularity with reduced effort can.

A solving this problem Add-drop device is specified in claim 1; this add-drop facility used cross-connect devices are in the claims 9 and 10 described.

Of the key advantage of the add-drop facility is that the majority the tributary signals over the longitudinal path guided will and over in the drop-add path only those signals will be performed, the one experience special treatment, for example, disconnected or coupled be regenerated or wavelength converted.

The Add-drop facility added the optical switching devices to a drop-add path, via the a small part of the tributary signals is passed.

Advantageous is in particular also the preselection of drop signals, which are then alone in the drop branch reinforced Need to become. In recent add-drop facilities, however, the received Wavelength-multiplexed signal by optical splitter first split into many signals, which then all had to be amplified before one Selection of individual signals (individual wavelengths) took place.

A Extension of the add-drop facility is through in the longitudinal path (Through-Path) and optical splitter and combiner inserted in the add-drop path easily possible.

One built with these add-drop devices optical cross-connector allows the photonic interconnection of optical tributary signals. in this connection the number and power of the optical amplifiers is minimized. After the selection Tibutary signals either pass through them or the conversion into electrical signals with a smaller granularity over a switched electrical switching field or a 3R electrical regeneration supplied can be.

One The Add-Filter provided in the Add branch ensures sufficient Noise in the free channels of the add branch that matches the over transmitted the longitudinal path channels be merged into a new multiplex signal.

at the components available today, it is currently still advantageous not all drop channels via to select a single optical filter, but by a Series connection of power splitters and wavelength-selective elements and optical switches to implement appropriate routing elements.

from Effort is also advantageous, not all possible Provide through-connection variants, but, according to requirements, to use simpler structures. For example, some need Tributary signals of the drop branch and / or the add branch not be freely switchable.

The Invention is based on embodiments described in more detail.

It demonstrate:

2 a schematic diagram of an add-drop device,

3 an advantageous expansion possibility of the add-drop device,

4 a first embodiment of the add-drop path and

5 a simplified embodiment of the add-drop path.

2 shows one of several add-drop devices of an optical cross-connector.

A first wavelength division multiplex signal MS1 is received via a fiber F of a WEST-EAST connection and an input of the add-drop device 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8th . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . 20 . 21 . 22 . 23 . 24 . 25 . 26 fed. This contains an optical amplifier 1 , a first splitter 2 which splits the wavelength division multiplex signal MS1 into two sub-signals, a multiplex-through signal MS _T and multiplex-drop signal MS _D , which are respectively supplied to a longitudinal path and to an add-drop path.

The Through Path (Optical Express Layer) implements the optical cross-connector PXC. It contains a series connection of a second splitter 3 , a signal splitter 4 (preferred example of a power splitter), a signal combiner 5 (preferably a multi-input tunable filter element (WSS)) and a first combiner 6 , The longitudinal path and the add-drop path are from a second combiner 7 summarized, which is an optical amplifier 8th is downstream. The series-connected splitters and combiners can also be replaced by other configurations according to the desired function and the intended expandability.

About a first exit of the first splitter 2 the multiplex-through signal MS _{T is} fed to the longitudinal path and the tributary-drop signals λ _D1 , λ _D2 , ... (channels) to be branched are fed through the adjustable filter element 5 acting as a wavelength-selective switch (WSS) 5 or Wavelengthblocker can be realized, locked or only the desired tributary-through signals λ _T1 , λ _T2 , ... are turned on. The illustration shows only the longitudinal path of a single add-drop device. Several of these add-drop devices work in a conventional manner as an optical cross-connector. From the multiple splitter, the multiplex-through signal MS _{T is divided} into a plurality of signals, which are then each supplied to an input of a wavelength-selective switch (corresponding to 5). Corresponding multiplex signals MS _T2 become the further inputs of the wavelength-selective switch 5 fed to the illustrated add-drop device.

A part of the complete receiving multiplex signal MS1 is a multiplex drop signal MS _D at a second output 2 ₂ the first splitter 2 branched off for the drop branch. This and one add branch of each add drop device together form the drop add path. The multiplex drop signal MS _D is here via an upgrade splitter 9 a controllable frequency-selective drop amplifier 10 . 11 (For example, a series circuit of a programmable filter and an amplifier). This amplifies only the tributary drop signals λ _D1 , λ _D2 , ... (channels), which are dropped (dropped). The output signal of the amplifier 10 , designated as the first WDM drop signal W _D1 = λ _D1 , λD ₂ ,..., becomes a first splitter switching device 12 fed. Of these, several are in a cross-connect device, for example 24 , but none of them except the first one still has the twenty-fourth splitter switching device 13 is shown, which is supplied from another add-drop device or connection NW, N, NE, SE, S or SW another WDM drop signal W _DM .

In every splitter switching device 12 . 13 , ... WDM drop signals W _D1 , W _D2 , ..W _DM through multiple splitters 12 ₁ . 13 ₁ , ... branches to several outputs. The respective downstream optical switches 12 ₁ . 13 ₂ (a button) select in the illustrated example of the plurality of WDM drop signals, the WDM drop signals W _D1 , W _D2 , .. and lead them to the filters 14 . 15 , .. too. The splitter switching devices 12 . 13 thus work as drop-routing elements for the WDM drop signals. The filters 14 . 15 then each select individual tributary drop signal λ _D1 ..., λ _D24 . These can then each have an add-drop-continue module 16 . 17 be routed and switched or output (or an add-drop module to be supplied, if no switching is to take place). When switching through a selected tributary drop signal λ _D1 as a tributary add signal λ _A1 of another add-drop device 28 fed. The same is done with selected tributary drop signals λ _D24 from other add-drop devices 27 come and be (added) in a WDM add signal W _{A1 of} the illustrated add-drop device inserted.

The drop signals can be accessed via the Add-Drop-Continue modules 16 . 17 also amplifiers, 3R regenerators or after opto-electrical conversion to the digital cross-connector EXC be supplied.

The add branch is structured according to the drop part. First, the tributary drop signals λ _A1 ,..., Λ _A24 to be inserted, in particular after an electro-optical conversion, are amplified by optical amplifiers 18 . 19 , ... strengthened. The amplifier noise is caused by tunable filters 20 . 21 suppresses before the tributary add signals λ _A1 , ..., λ _A24 via combiner switching devices 22 . 23 be merged. The combiner switching devices, which correspond to the splitter switching devices 12 . 13 , ... are set up and work as add-routing elements, corresponding to the drop branch have optical switches 22 ₁ . 23 ₁ and multiple combiners 22 ₂ . 23 ₂ on.

The added to a WDM add signal W _A1 add signals λ _A24 , ... are via an upgrade combiner 24 , a frequency-selective add-amplifier 25 . 26 and a second combiner 7 and added to the loop-through signals λ _T5 , λ _T5 , ... added. All output tributary signals are in an optical amplifier 8th reinforced again.

The adjustable frequency-selective add-amplifier 25 . 26 or a controllable filter 26 , which passes only the add signals, serves in the add branch in particular for suppressing the amplifier noise and also prevents a collision of the inserted tributary add signals λ _A24 , ... with the looped tributary-through signals λ ₅ , λ ₆ , ... in case of malfunction.

As already described, further tributary drop signals are usually generated by additional add-drop devices (connections), not shown. 27 the other splitter switching devices 13 fed. Accordingly, in the add branch of the combiner switching devices 23 , ... further tributary add signals of further add-drop devices, not shown 28 fed. The associated connections are here designated with the directions NW, N, NE, SE, S, SW. A corresponding device represents a photonic cross-connector PXC.

To extend the add-drop device or the cross-connect device are the upgrade splitter 9 or the upgrade combiner 24 provided as well as the splitter 3 and the combiner 6 intended.

The connection with an electrical cross-connector EXC is made via the Add-Drop-Continue modules 16 . 17 , After an opto-electrical conversion of the tributary signals, for example SDH signals, the EXC electrical cross-connector can divide them into signals of arbitrary granularity and switch them through with this granularity. The combination of photonic and electrical cross-connector leads to a cross-connect device with a wide range of applications with little effort.

3 shows an expansion option of the add-drop device. In a first expansion stage, a wavelenght blocker (WB) is in the longitudinal branch 29 switched on, which blocks the signals to be dropped. If the add-drop device is to be extended, ie if more individual signals are to be branched off in order to be inserted into further multiplex signals, the branching takes place here via the splitter arranged in the longitudinal branch 3 , The tributary signals selected from the multiplex sub-signals MS _DN and MS _DS (the drop branch is in 3 not shown) should now be sent in the north and south direction. Corresponding WDM add signals W _AN , and WAS, for example, via a wavelength-selective switch 30 - or via other Wavelenghtblocker not shown - out and in the combiner 6 summarized with the guided over the longitudinal path tributary signals.

Additional enhancements to the add-drop facility, in particular the signal routed via the drop-add path, are also available through the upgrade splitter 9 and the upgrade combiner 24 possible. As a result, an add-drop device can be gradually expanded to become a powerful cross-connector.

However, a fixed preselection of the drop signals can already be done by an interleaver "I" as an element 9 respectively. Also, the arrangement of couplers 2 . 3 , Interleaver 9 and Wavelengthblocker 29 be replaced by a wavelength-selective switch.

4 shows a further concrete embodiment of the invention. In order to understand the function of the arrangement easier, abbreviations for components have been added in addition to the reference numerals. WSS wavelength selective switches, PS power splitters, PC power combiners, RF drop filters, and TF add filters. Shown are only two of several possible drop-add paths each from a second output 2 ₂ of the splitter 2 to the second entrance 7 ₂ of the combiner 7 or between corresponding terminals of the other add-drop devices. Other identically constructed drop-add paths are only indicated by dots. The first multiplex drop signal MS _D1 is first via a splitter 31 divided into several more equal multiplex sub-signals and then wavelength-selective switches 32 ₁ to 32 _N fed, each one or more tributary signals select, here the tributary drop signals λ _D1 , λ _D2,.

An output signal of the wavelength-selective switch 32 ₁ the WDM drop signal W _D1 is supplied to the upper drop branch; that through the wavelength-selective switch 32 _N Preselected WDM drop signal W _DM , on the other hand, is fed to the lowest drop branch. The other undesignated outputs of the wavelength-selective switches 32 ₁ to 32 _N serve the expansion of the panel or are supplied to the drop branches of other add-drop devices (for other connections). Thus, the upper drop branch will receive further WDM drop signals, for example from the wavelength-selective switch 37 supplied, this is shown for the WDM drop signal W _DM . The combination of splitters and wavelength-selective switches always serves to preselect the tributary drop signals.

The WDM drop signals W _D1 are in optical amplifiers 10 ₁ , ..., 10 _m amplified and then each over another splitter 12 ₁ , ..., 13 ₁ split again. This division into Sd sub-signals is carried out according to the switching capacity and the required signal level. The outputs of these splitters are each with one input of M: 1 switches 12 ₂ to 13 ₂ connected. Corresponding 2 only two of the (space) switches of the upper drop branch are shown. The arrangement again corresponds to a drop-routing element.

The outputs of the M: 1 switches 12 ₂ to 13 ₂ are each a tunable filter 14 downstream, so that the individual selection of a tributary drop signal is possible (an alternative to Combination of switches 12 ₂ and 13 ₂ and filters 14 , ... represent further wavelength-selective switches). This arrangement of the splitter and wavelength-selective switch and the filter thus again corresponds to the series connection of a wavelength routing element and a selection device.

As already briefly described, of further add-drop devices, here the lower one, if the corresponding switching flexibility is desired, in each case a WDM drop signal from the output of an associated wavelength-selective switch 37 via an amplifier 10 _m to the splinters 10 _m , ... of the drop branch just described. This arrangement thus corresponds functionally to the simpler embodiment according to 2 ,

About Add-Drop-Continue modules 16 For example, each selected tributary signal λ _D1 ,... can be optically amplified or fed to an add branch of another add-drop device after conversion into an electrical signal of a 3R regeneration. Likewise, the tributary signal can only be regenerated and reinserted. After conversion into electrical form by the optoelectronic transducer 42 it can be supplied to the electrical cross-connector EXC, so that the passage of signals of smaller granularity is possible.

The add branch is constructed largely according to the drop branch, with the position of the add filter being off 2 equivalent. First, optical tributary add signal λ _{A1 to be added} in an optical amplifier 18 amplifies and then the noise components outside the spectrum of the tributary add signal through a filter 20 reduced. In order to enable the insertion of this tributary add signal λ _A1 into different multiplex signals, it can be implemented by a 1: M space switch 22 ₁ be switched to different outputs, in turn, with different combiners 22 ₂ to 23 ₂ are connected. The outputs of the combiner 22 ₂ to 23 ₂ , where multiple tributary add signals are issued or a WDM add signal is delivered, are again with inputs from other combiners 34 , ... connected. Via an optical amplifier 35 Here are the one wavelength-selective switch 36 fed and combined with other WDM add sockets. The wavelength-selective switch 36 again serves to filter out unwanted noise spectra. Whether several single amplifier 35 , ... are necessary or after combining signals a common optical amplifier suffices, which only follows a wavelength-selective switch Wavelengthblocker, depends on the size of the photonic cross-connector PXC and its dimensions. The wavelength selective switch can be controlled by a controllable filter, a wavelength blocker 2 to be replaced.

ever according to existing components can also Splinters and wavelength-selective Combined switch and combiner and wavelength-selective switch become.

5 shows a partially simplified embodiment of the drop branches of an add-drop device. A splinter 40 with several outputs, to the Wavelengthblocker (WB) 38 and 39 is working here as a wavelength routing element, which allows to branch off some WDM drop signals through the amplifier 10 ₁ and the splinter 12 ₁ be guided. To the outputs of the splitter 12 ₁ In each case a filter is turned on, each of which allows the selection of a tributary drop signal. The tributary drop signals can in turn via the add-drop-continue module 16 be supplied to the electrical coupling field or a regenerator. The add branch can be symmetrical to the drop branch or as before. A following drop branch, by a splitter 2 ₂₂ receives a multiplex sub-signal MS _D2 , splits this into a splitter 41 in three sub-signals from which further WDM drop signals are selected by Wavelengthblocker. Two WDM drop signals are routed as described in the first add drop path, while the third WDM drop signal is routed as in 4 described, the drop branch of another add-drop device is supplied and can be routed together with the obtained from the WDM sub-signal MS _DM WDM drop signal WD _M. Any mixed forms are possible here.

1

optical amplifier

2

first splinter

3

second splinter

4

Multiple Splitter

5

controllable filter

6

first Assemblers

7

second Assemblers

8th

optical Add-amplifier

9

Upgrade Splitter

10

Drop amplifier

11

adjustable Drop filters

10.11

frequency selective amplifier

12.13

Splitter switching device / drop routing element

12 ₁ , 12 ₂ , 13 ₁ , 13 ₂

Drop routing element

12 ₁

Multiple Splitter

12 ₂

optical (M: 1) switch (switching device)

13 ₁

Multiple Splitter

13 ₂

(M: 1) switch

14.15

tunable filter

16.17

Add-drop-continue module

18.19

optical amplifier

20.21

tunable filter

22

Assemblers switching device

22 ₁

optical switch

22 ₂

Multi-Assemblers

23

Further Assemblers switching device

22.23

Add-routing element

22 ₁ , 22 ₂ , 23 ₁ , 23 ₂

Add-routing element

24

Upgrade Assemblers

25

Add-amplifier

26

adjustable Add filter

27

Further Add-drop device

28

Further Add-drop device

29

Wavelength blocker

30

wavelength selective Element / wellenlängenselek

tive switch

31

splinter

32 ₁

wavelength selective switch

32 _N

wavelength selective switch

33

splinter

34

Assemblers

35

optical amplifier

36

wavelength selective switch

37

wavelength selective switch

38

Wavelength blocker

39

Wavelength blocker

40

splinter

41

splinter

42

optoelectronic converter

MS1

Wavelength-multiplexed signal

MS _T

Multiplex-through signal

MS _D

Multiplex drop signal

W _D

WDM signal Dropp

W _A

WDM add signal

RF

receive filter

TF

transmission filter

SS

Space Switch

WSS

wavelength-dependent switch

PC

Power Combiner

λ _D1

Tributary drop signal

λ _A1

Tributary add signal

PS

power splinter

M

number the multiplexed signals

λ _A

Add-multiplexed signal

λ _AX

Add-multiplexed signal

λ _D

Drop multiplex signal

λ _DX

Drop multiplex signal

EXC

digital Cross Connector

PXC

photonic Cross Connector

OTC

Optical tributary Connection

Claims (12)

Add-drop device, to which a wavelength division multiplexed optical signal (MS1) is fed, with a longitudinal branch ( 3 . 4 . 5 . 6 ), which is the at least one wavelength-selective element ( 4 . 5 . 29 . 30 ), which passes only tributary-through signals (λ _T5 , λ _T6 , ...), with a drop branch ( 9 . 10 . 11 . 12 . 14 ), to which a coupled multiplex drop signal (MS _D ) is fed and which further wavelength-selective elements ( 10 . 11 ; 32 ₁ . 32 _N ) for selecting, and with an add branch ( 19 . 21 . 23 . 24 . 25 . 26 ) coupled via the tributary add signals (λ _A1 , λ _A2 , ...) and summarized with guided over the longitudinal branch tributary-through signals (λ _T5 , λ _T6 , ...) to a transmitted multiplex signal (MS2) characterized in that the through path is a signal distributor ( 4 ) via which through-signals (MS _T ) are supplied to other add-drop devices such that the through path is a signal combiner ( 5 ) through which through signals (MS _T2 ) are received by other add-drop devices that in the drop branch ( 9 . 10 . 11 . 12 . 14 ) Drop-routing elements ( 12 . 13 ; 12 ₁ . 12 ₂ . 13 ₁ . 13 ₂ ) are arranged, over which the tributary drop signals (λ _D1 , λ _D2 , ...) are guided, that the drop-routing elements ( 12 . 13 ; 12 ₁ . 12 ₂ . 13 ₁ . 13 ₂ ) adjustable filter elements ( 14 . 15 ), which perform an individual selection of the tributary drop signals (λ _D1 , λ _D2 ,...) and that in an add branch add routing elements (FIG. 22 . 23 ; 22 ₁ . 22 ₂ . 23 ₁ . 23 ₂ ) are arranged over the tributary add signals (λ _A1 , λ _A2 , ...) are guided. Add-drop device according to claim 1, characterized in that in the drop branch ( 9 . 10 . 11 . 12 . 14 ) wavelength-selective elements ( 10 . 11 ) for preselecting a WDM drop signal composed of tributary drop signals (λ _D1 , λ _D2 ...) (W _D = λD ₁ , λD ₂ , ...); that only the preselected WDM drop signal (W _D = λ _D1 , λ _D2 ,...) is a drop amplifier ( 10 ), that the preselected WDM drop signal (W _D = λ _D1 , λ _D2 ,...) is transmitted via the drop routing elements (FIG. 12 . 13 ; 12 ₁ . 12 ₂ . 13 ₁ . 13 ₂ ) to be led. Add-drop device according to claim 1, characterized in that in the add branches ( 18 . 20 . 22 , ...; 19 . 21 . 23 . 24 . 25 . 26 ) each have an adjustable filter element ( 20 . 21 ) is arranged with bandpass characteristics, over which a tributary-add signal (λ _A24 ) is guided, and that the outputs of these filter elements ( 20 . 21 ) with add-routing elements ( 22 . 23 ) which combine the tributary add signals (λ _A1 , ..., λ _A24 ) into a WDM add signal (W _A ). Add-drop device according to claim 2, characterized in that in the add branch ( 19 . 21 . 23 . 24 . 25 . 26 ) a wavelength-selective element ( 26 ), via which the WDM add signal (W _A ) is performed. Add-drop device according to claim 1 or 3, characterized in that in the drop branch and / or in the longitudinal branch upgrade splitter ( 9 . 3 ) are provided via which further multiplex drop signals (W _DN , W _DS ) are branched off, and that in the add branch and / or in the longitudinal branch an upgrade combiner ( 24 . 6 ) is provided, can be coupled via the other WDM add signals (W _AN , λ _AS ). Add-drop device according to claim 4, characterized in that one of the combiners ( 6 . 24 ) in an extension another wavelength-selective element ( 30 ), via which further WDM add signals (W _AN , W _AS ) are inserted. Add-drop device according to one of the preceding claims, characterized in that an add-drop-continue module ( 16 . 17 ) is provided, through which the tributary drop signals (λ _D1 , λ _D2 , ..) are switched through or branched off and the tributary add signals (λ _A1 , λ _A2 , ..) can be inserted or that an add -Drop module is provided, via which the tributary drop signals (λ _D1 , λ _D2 , ..) can be branched off and the tributary add signals (λ _A1 , λ _A2 , ..) are inserted. Add-drop device according to claim 7, characterized in that via the add-drop-continue module ( 16 . 17 ) or the add-drop module a regenerator or a wavelength converter is connected. Cross-connector for optical signals, characterized in that the cross-connector consists of several add-dropp devices ( 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8th . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . 20 . 21 . 22 . 23 . 24 . 25 . 26 ) is formed according to one or the preceding claims. Cross-connect device for switching through optical and electrical signals with a photonic cross-connector (PXC) and with an electrical cross-connector (EXC), characterized in that the photonic cross-connector (PXC) has several add-dropp devices ( 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8th . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . 20 . 21 . 22 . 23 . 24 . 25 . 26 ) according to one or claims 1 to 7. Cross-connector device according to claim 8, characterized in that in the drop branch ( 31 . 32 ₁ . 12 ₁ . 12 ₂ . 14 . 16 ) an add-drop device a first preselection element ( 31 . 32 ₁ , ..., 32 _N ), the input of which is supplied with a first multipex-drop signal (MS _D1 ) and with WDM drop signals (W _D1 , preselected tributary-drop signals (λ ₁ , λ ₂ ,. W _D2 ) are sent to the outputs of the preselection element ( 31 . 32 ₁ , ..., 32 _N ) an optical amplifier ( 10 ₁ . 13 ₁ ), that inputs of the drop-routing elements ( 12 ₁ . 12 ₂ , ..., 13 ₁ . 13 ₂ ) each via the amplifier ( 10 ₁ . 13 ₁ ) with an output of preselection elements ( 33 . 37 ) are connected to further add-drop devices, wherein a drop-routing element ( 12 ₁ . 12 ₂ , ..., 13 ₁ . 13 ₂ ) several 1: SD splitter ( 12 ₁ , ..., 13 ₁ ) and several optical M: 1 switches connected to their outputs ( 12 ₂ , ..., 13 ₂ ) and at least from another wavelength multiplex signal (MS _M ) another WDM drop signal (W _DM ) is supplied, that in each case an adjustable filter ( 14 ) to an output of the M: 1 optical switch ( 12 ₂ . 13 ₂ ) is turned on for selecting a respective tributary drop signal (λ _D1 , λ _D2 , ...), that a selected tributary drop signal (λ _D1 ) via an add-drop-continue modules ( 34 ) or fed to the electrical cross-connector (EXC), that in the add branch the tributary add signals (λ _A1 ) are switched to a 1: M switch ( 22 ₁ ) and that outputs of several 1: M switches ( 22 ₁ ) with inputs from combiners ( 22 ₂ . 23 ₂ . 34 ) which combine the tributary add signals (λ _A1 ) into a WDM add signal (W _A1 ). Cross-connector device according to claim 8, characterized in that in a drop branch a preselection element ( 37 . 38 . 39 ) is supplied to a first multiplex drop signal (MS _D1 ), the multiplex drop signal (MS _D1 ) in several different tributary drop signals (λ _D1 , λ _D2 , λ _3D , λ _D4 , ... ) WDM drop signals (WD1, WD2) divides that to the outputs of the preselection element ( 37 . 38 . 39 ) Amplifier ( 10 ₁ . 10 ₂ ) are connected to outputs of the amplifier ( 10 ₁ . 10 ₂ ) as RoutingElements each a splitter ( 12 ₂ ) is turned on and that to the outputs of the splitter ( 12 ₂ ) adjustable filters ( 14 ) are connected to the individual selection of tributary drop signals (λ _D1 ) whose outputs each with one of the add-drop-continue modules ( 16 ) are connected.