KR20000020170A - Extensible nonblocking optical matrix switching device - Google Patents

Abstract

PURPOSE: An extensible nonblocking optical matrix switching device is provided to increase the number of input pot and output port by using a predetermined optical switch. CONSTITUTION: An extensible nonblocking optical matrix switching device comprises a first optical switching device, a multitude of optical matrix switching devices, and a second optical switching device. The first optical switching device performs a switching operation by dividing input signals through a multitude of input ports to a multitude of optical signals. The optical matrix switching device performs an optical matrix switching operation for the switched optical signals. The second optical switching device combines the optical signals received from the first optical switching device and outputs the combined signals to a multitude of output ports.

Description

Scalable Non-Blocking Optical Matrix Switching Device

The present invention relates to an expandable nonbloking optical matrix switching device utilized as a spatial switch of an optical crosslinking system used to perform node-to-node interconnection of an optical transmission network. An optical matrix switching device for switching to an output port by performing a matrix switching operation on an optical signal input to an input port having an output port.

Current commercial optical network uses optical fiber to send a large amount of multiplexed information over long distances from transmitting terminal to receiving terminal. It is expected that wavelength division multiplexing will be widely used to effectively utilize the wide transmission wavelength band of such optical fiber. do.

The optical crossover connector has the function of connecting any of the plurality of inputs to any of the plurality of outputs for reconstruction of the optical path and restoration of the network. As such, an essential component for selectively interconnecting nodes in a network is a large matrix or cross-connect switch.

The optical matrix switch proposed by H. Okuyama et al. Is connected in a tree structure as shown in FIG. 1 to receive optical input signals from 2 ^{i + 1} input ports (where i is a natural number). 1 x 2 branch, which divides them into 2 ^{i + 2} branch signals, is connected in series to the input branch to form a double tree structure, with each 2 ⁱ x 2 ⁱ optical switch having 2 ⁱ different input ports Four 2 ⁱ x 2 ⁱ optical switches that receive signals from the two, and a tree structure connected to receive the switch output signals from the 2 ⁱ x 2 ⁱ optical switches and provide optical output signals to 2 ^{i + 1} output ports It consists of a 2 x 1 coupling portion and the like. [Reference: US Patent No. 4852958, Aug. 1, 1989, Optical matrix switch having optimized crosstalk characteristics and uniform optical output intensity].

1 is a block diagram of a conventional optical matrix switching device, which is connected to 2 ^{i + 1} input ports IP1 to IP2 ^{i + 1} and 1 x 2 minutes respectively connected to the input ports IP1 to IP2 ^{i + 1} . Bases D1 to D2 ^{i + 1} , 2 ⁱ x 2 ⁱ optical switches 110 and 120 connected to the output terminals of the 1 x 2 branching portions D1 to D2 ⁱ , and the input terminals are 1 x 2 minutes. 2 ⁱ x 2 ⁱ optical switches 130 and 140 connected to the output terminals of the bases D (2 ⁱ +1) to D2 ^{i + 1} , and two input terminals are 2 ⁱ x 2 ⁱ optical switches 110 and 130. 2 x 1 coupling units C1 to C2 ⁱ connected to the output terminal of the field, and 2 x 1 coupling units C (2 ⁱ +1 connected to the output terminal of the 2 ⁱ x 2 ⁱ optical switches 120 and 140. ) To C2 ^{i + 1} ) and output ports OP1 to OP2 ^{i + 1} connected to the 2 × 1 coupling units C1 to C2 ^{i + 1} , respectively.

As described above, the output optical signal of the 1 x 2 branching parts D1 to D2 ⁱ or the output optical signal of the branching parts D (2 ⁱ +1) to D2 ^{i + 1} is a 2 ⁱ x 2 ⁱ optical switch ( 110, 120, or 2 ⁱ x 2 ⁱ optical switches 130, 140, or the like.

The switching operation of the conventional optical matrix switching device having the structure as described above is as follows.

When an optical signal input from the outside is transmitted to the branch parts D1 to D2 ^{i + 1} through the input ports IP1 to IP2 ^{i + 1} , the 1 × 2 branch parts D1 to D2 ⁱ are each input one. The optical signal is split into two optical signals and output to the 2 ⁱ x 2 ⁱ optical switches 110 and 120, and the 1 x 2 branching parts D (2 ⁱ +1) to D2 ^{i + 1} are respectively input. One optical signal is branched into two optical signals and output to the 2 ⁱ x 2 ⁱ optical switches 130 and 140.

Subsequently, the 2 ⁱ x 2 ⁱ optical switch 110 switches 2 ⁱ optical signals input from the 1 x 2 branching parts D1 to D2 ⁱ to 2 x 1 coupling parts C1 to C2 ⁱ , The 2 ⁱ x 2 ⁱ optical switch 120 receives 2 ⁱ optical signals inputted from the 1 x 2 branching parts D1 to D2 ⁱ and 2 x 1 coupling parts C (2 ⁱ +1) to C2 ^{i + 1.} ) switching and, 2 ⁱ x 2 ⁱ in the optical switch 130 is 1 x 2 branching portion (D (2 ⁱ +1) 2 x 1 2 ⁱ coupled to a single optical signal input from ^{i + 1} to D2) unit (C1 to C2 ⁱ⁾ and switching into, and 2 ⁱ x 2 ⁱ the optical switch 140 of the 2 ⁱ input from the 1 x 2 branching portion (D (2 ⁱ +1) to D2 ^{i + 1)} The optical signal is switched to 2 x 1 coupling units C (2 ⁱ +1) to C2 ^{i + 1} .

As such, when the optical signals are transferred to the 2 x 1 coupling units C1 to C2 ^{i + 1} through a matrix switching operation, the 2 x 1 coupling units C1 to C2 ^{i + 1} are respectively ¹ of 2 input optical signals. Outputs to the output ports OP1 to OP2 ^{i + 1} .

In addition, the conventional optical matrix switching device as described above can be expanded to the size of the 2 ^{i + 1} x 2 ^{i + 1} optical switch using a basic 2 x 2 optical switch. That is, in this structure, two ^{i + 1} input and output ports of the optical matrix switching device can be doubled. For example, when the number of first input / output ports is 8, according to the above structure, the number of input / output ports can be expanded to 16, 32, 64, and the like.

However, the structure of the conventional optical matrix switching device is difficult to modularize, and also difficult to continuously expand.

Accordingly, the present invention has been made to solve the above problems, by employing predetermined optical switches to extend the number of input ports and output ports by an integer multiple of M to MN (where M and N are natural numbers). Accordingly, an object of the present invention is to provide an optical matrix switching device capable of gradually increasing the switching capacity by allowing the number of first input and output ports to be expanded by integer multiples.

1 is a block diagram of a conventional optical matrix switching device.

2 is a block diagram of an exemplary embodiment of an expandable non-blocking optical matrix switching device according to the present invention.

Explanation of symbols on the main parts of the drawings

IP1 to IP (MN): input port

211 to 21 (MN): 1 x N Optical Switch

221 to 22N ² : M x M optical matrix switch

231 to 23 (MN): N x 1 optical switch

OP1 to OP (MN): output port

In order to achieve the above object, the present invention provides an optical matrix switching device that is used as a space switch of an optical cross connection system, wherein the optical signals input through a plurality of input ports are divided into a plurality of optical signals. A plurality of first optical switching means for switching; A plurality of optical matrix switching means for optical matrix switching a plurality of optical signals switched from the plurality of first optical switching means; And a plurality of second optical switching means for combining the plurality of optical signals transmitted from the plurality of optical matrix switching means to switch to the plurality of output ports.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a block diagram of an exemplary embodiment of an expandable non-blocking optical matrix switching device according to the present invention.

As shown in FIG. 2, the optical matrix switching device according to the present invention includes 1 x N optical switches 211 to MN input ports IP1 to IPMN and input terminals connected to the input ports IP1 to IPM. 21M, 1 x N optical switches 21 (MN-M + 1) to 21 (MN), whose inputs are connected to input ports IP (MN-M + 1) to IP (MN), M x M optical matrix switches 221 to 22 N connected to one output terminal among the N output terminals of the 1 x N optical switches 211 to 21M, respectively, and M input terminals to the 1 x N optical switch 21. M x M optical matrix switches 22 (N ² -N + 1) to 22N ² connected to one output terminal among the N output terminals of (MN-M + 1) to 21 (MN)), and N input terminals N x 1 optical switches 231 to 23M connected to one output terminal among M output terminals of M x M optical matrix switches 221, 22 (N + 1), ..., 22 (N ² -N + 1). And N input stages are M × M optical matrix switches 22N, 22 (2N), ·, 22N ²⁾ N x 1 optical switch (23 (MN-M + 1 ) to 23 (MN)) and, N x 1 optical switches (231 to 23 (MN) connected to the one output terminal in the M number of output stages of Output ports OP1 to OP (MN) connected to the output terminals of the terminals.

Here, 1 x N optical switches 21 (M + 1) to 21 (MN-M), which are omitted, and M x M optical matrix switches 22 (N + 1) to 22 (N ² -N) ) And N x 1 optical switches 23 (M + 1) to 23 (MN-M) are also connected and provided in the same manner.

And, MN of 1 x N optical switch so that a MN ² of the optical branch signal from (211 to 21 (MN)). In addition, M x M optical matrix switches 221 to 22N ² are connected to the 1 x N optical switches 211 to 21 (MN) to form a composite tree together with the 1 x N optical switches 211 to 21 (MN). To form.

Referring to the operation of the optical matrix switching device of the present invention having the structure as described above in detail as follows.

When optical signals input from the outside are transmitted to the 1 x N optical switches 211 to 21 (MN) through the input ports IP1 to IPMN, the 1 x N optical switches 211 to 21M are respectively input ports IP1. Through the optical signals transmitted through the IPMs to N optical signals to switch to the M x M optical matrix switches 221 to 22N, and likewise, the 1 x N optical switches 21 (MN-M + 1) to 21. (MN) also divides the optical signal transmitted through the input ports (IP (MN-M + 1) to IP (MN)) into N optical signals, respectively, to form an M x M optical matrix switch 22 (N ² −). N + 1) to 22N ² ).

Here, 1 x N optical switches 21 (M + 1) to 21 (MN-M), which are omitted, and M x M optical matrix switches 22 (N + 1) to 22 (N ² -N) ) Operate in the same way.

Then, MN ² optical branch signals are obtained by 1 × N optical switches 211 to 21 (MN).

Subsequently, the M x M optical matrix switches 221 to 22N receive one branched optical signal from the 1 x N optical switches 211 to 21M, respectively, and N x 1 connected M optical signals to a desired output port. Matrix switching with the optical switches 231-23MN, and the M x M optical matrix switches 22 (N ² -N + 1) to 22N ² also have 1 x N optical switches 21 (MN-M + 1), respectively. ) And 21 (MN)) to receive the branched optical signal one by one to M matrix signals are switched to the N x 1 optical switch 231 to 23 (MN)) connected to the desired output port.

Here, the drawn M x M photomatrix switches 22 (N + 1) to 22 (N ² -N) are also operated in the same manner.

As such, when the input optical signals are matrix switched and transferred to the N x 1 optical switches 231 to 23 (MN), the N x 1 optical switches 231 to 23 MN are respectively M x M optical matrix switches 221 to 22 N. ² ) switch to one of the N optical signals transmitted from the selection output ports OP1 to OP (MN).

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, the present invention can expand the number of input ports and output ports by an integer multiple of M to MN by adding M x M optical matrix switches, 1 x N optical switches, and N x 1 optical switches. As a result, the number of first input and output ports can be increased by an integer multiple of the number of input and output ports, which not only doubles the number of input ports and output ports, but also gradually increases the switching capacity. By modifying the configuration and modularization, the initial installation cost can be reduced.

Claims (4)

In an optical matrix switching device utilized as a space switch of an optical cross connection system, A plurality of first optical switching means for branching and switching the optical signals input through the plurality of input ports into a plurality of optical signals; A plurality of optical matrix switching means for optical matrix switching a plurality of optical signals switched from the plurality of first optical switching means; And A plurality of second optical switching means for combining a plurality of optical signals transmitted from the plurality of optical matrix switching means and switching to a plurality of output ports Scalable non-blocking optical matrix switching device comprising a. The method of claim 1, The plurality of first optical switching means, respectively, 1 x N optical switch for branching one optical signal input through the input port into N (where N is a natural number) optical signal and switching to the optical matrix switching means Scalable non-blocking optical matrix switching device comprising a. The method of claim 1, The plurality of optical matrix switching means, respectively M x M optical matrix switch for switching M optical signals to the plurality of second optical switching means by switching M optical signals inputted from the first optical switching means (where M is a natural number). Scalable non-blocking optical matrix switching device comprising a. The method of claim 1, The plurality of second optical switching means, respectively N x 1 optical switch which combines N optical signals transmitted from the plurality of optical matrix switching means (where N is a natural number) into one signal and switches to the output port Scalable non-blocking optical matrix switching device comprising a.