JP2003259403A - Optical crossconnect and optical path network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control loss or deterioration of an optical signal incident to 3R processing and to utilize the port effectively. <P>SOLUTION: A 3R trunk is interposed between the output port and an output transmission line contained in the output port. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is used in optical communication.
In particular, it relates to a 3R (Reshaping; Retiming; Regenerating) processing technique.

[0002]

2. Description of the Related Art In an IP (Internet Protocol) network, IP
The header information of the packet is read, and routing is performed based on the IP address (hereinafter referred to as IP transfer). In the IP transfer in the optical path network, when a series of large amount of data (hereinafter referred to as burst data) is divided into a large number of IP packets and transferred, the header information of each IP packet is read in order to read the header information of each IP packet. It is necessary to convert the signal into an electrical signal once. In order to transfer burst data at high speed by omitting such conversion processing, there is a burst data transfer method in which a cut-through path is set between a source node and a destination node. That is, in the cut-through path, since it is not necessary to read the header information of a large number of IP packets forming the burst data, the optical signal can be transferred as it is, and the burst data transfer can be performed at high speed.

At this time, if the distance between the originating node and the terminating node is long, loss of optical signals or deterioration of signal quality occurs. Therefore, when setting a long-distance cut-through path, 3R processing is required on the way.

In this specification, a source node and a destination node are called a node that sends a request for path setting prior to data transfer, and a destination of this request. This node is called the destination node. At the time of data transfer after the path is set, either the source node or the destination node can be the data source or the data destination. Further, the set path may be a unidirectional path or a bidirectional path.

A conventional 3R processing configuration will be described with reference to FIG. Conventionally, when setting a cut-through path, a portion to be subjected to 3R processing on the cut-through path is calculated in consideration of various factors that cause loss or signal quality deterioration in the optical path network. At that point, as shown in FIG. 4, 3R processing is performed by the 3R trunk 20 provided at the output port of the wavelength conversion unit 10.

[0006]

In the conventional 3R processing configuration, two wavelength conversions are required to perform the 3R processing. That is, the wavelength of the input port to which the optical path requiring 3R processing is connected is converted to the wavelength of the output port connected to the 3R trunk, and after the 3R processing is performed by the 3R trunk, the wavelength is connected to the 3R trunk. The wavelength of the input port is converted into the wavelength of the predetermined output port.

As described above, since the wavelength conversion needs to be performed twice, there is a problem that an optical signal is lost or deteriorated. That is, it is a 3R process for compensating for the loss or deterioration of the optical signal, and it is desirable that the loss or deterioration of the optical signal due to the 3R process be suppressed as much as possible, but the conventional 3R processing configuration does not satisfy the requirement. Does not reach.

Furthermore, it is necessary for the 3R trunk to occupy a part of the input port and the output port of the optical cross connect, and there is a problem that the effective use of the port is hindered.

The present invention has been made in view of such a background, and an optical cross connect capable of suppressing loss or deterioration of an optical signal due to 3R processing and effectively utilizing a port. And to provide an optical path network.

[0010]

A first aspect of the present invention is an optical cross-connect, which is characterized by an input port for accommodating an input transmission path through which an optical signal arrives, and an input port for the input port. The wavelength conversion means for converting the wavelength of the optical signal input from the port into the wavelength corresponding to the destination, and the output port for accommodating the output transmission path for outputting the optical signal wavelength-converted by the wavelength conversion means are provided. A means for performing 3R processing is provided between at least a part of the output ports and the output transmission path accommodated in the output ports.

That is, according to the present invention, by inserting the 3R trunk between the output port and the output transmission line accommodated in this output port, the number of wavelength conversions associated with the 3R processing can be reduced, and The 3R trunk is directly connected to the output transmission line, and the provision of the 3R trunk can prevent the port from being occupied.
As a result, it is possible to suppress the loss or deterioration of the optical signal due to the 3R processing, and it is possible to effectively use the port.

A second aspect of the present invention is an optical path network comprising the optical cross connect of the present invention.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical cross connect according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the optical cross connect of this embodiment. FIG. 2 is a diagram for explaining the operation of the optical cross connect of this embodiment.

This embodiment is an optical cross connect, and the feature of this embodiment is that, as shown in FIG. 1, input ports I1 to I for accommodating an input transmission path through which an optical signal arrives are accommodated.
5, a wavelength converter 10 for converting the wavelengths of the optical signals input from the input ports I1 to I5 into a wavelength corresponding to the destination, and the optical signals wavelength-converted by the wavelength converter 10. Output port O accommodating the output transmission path
1 to O5, and 3R trunks 21 and 22 are interposed between some output ports O1 and O2 and the output transmission lines accommodated in the output ports O1 and O2. .

As shown in FIG. 2, the optical cross-connect of this embodiment has a wavelength λ1 at each of the input ports I1 to I5.
Optical signals of λ5 are input. These optical signals are wavelength-converted by the wavelength conversion unit 10 according to their destination routes, and the wavelengths λ1 to λ are output from the output ports O1 to O5, respectively.
5 is output as an optical signal.

In the example of FIG. 2, output ports O1 and O2
The 3R trunks 21 and 22 are connected to the 3R trunk, and the optical signal of the wavelength λ1 input from the input port I1 is not subjected to the wavelength conversion as it is, but is output from the output port O1 of the wavelength λ1 by the 3R trunk 21. 3R processing is performed. Further, the optical signal of wavelength λ3 input from the input port I3 is wavelength-converted to the wavelength λ2 by the wavelength conversion unit 10 and output from the output port O2 of the wavelength λ2 to output 3R.
3R processing is performed by the trunk 22.

That is, in the optical path network using the optical cross-connect according to the present embodiment shown in FIG. 2, when setting a cut-through path that requires a 3R process in the middle of a long distance, the wavelength λ1 or λ2 is the destination. Select the wavelength to be the route. As a result, the 3R processing is performed when the cut-through path passes through the optical cross connect of FIG. At this time, the number of wavelength conversions is only one wavelength conversion that is normally performed in the optical cross connect, and no special wavelength conversion for performing the 3R processing is required.

An actual operation method in the optical path network of the optical cross connect according to this embodiment will be described with reference to FIG. FIG. 3 is a diagram for explaining an operation method of the optical cross connect of this embodiment. In the example of FIG. 3, the originating node 31 is connected by an optical path of wavelength λ1.
At this time, when a cut-through path is set from the calling-side node 31 to the receiving-side node 41, the calculation result that the 3R process is required on the way due to the long distance is given. At 31, the destination node 41 is notified in advance that the cut-through path is set by the wavelength λ1 or λ2. Upon receipt of this notification, the node 41 notifies the node 31 of the acceptance of the cut-through path with the wavelength λ1 or λ2. At the node 31 receiving this notification, the wavelength λ
A cut-through path for the node 41 is set by 1 or λ2. As a result, a cut-through path for performing the 3R processing by the optical cross connect is set between the source-side node 31 and the destination-side node 41.

Further, when a cut-through path is set from the originating node 31 to the terminating node 42, if the calculation result is that 3R processing is not required on the way because of the short distance, the originating side node In node 31, node 4 on the receiving side
2, the wavelength other than the wavelength λ1 or λ2 (here, λ
Notify in advance that a cut-through path will be set according to 3). At the node 42 that received this communication, the wavelength λ3
If the acceptance of the cut-through path is approved by, the node 31 is notified of that fact. The node 31 receiving this notification sets a cut-through path for the node 42 with the wavelength λ3. As a result, a cut-through path that does not undergo the 3R processing by the optical cross connect is set between the source-side node 31 and the destination-side node 42.

[0020]

As described above, according to the present invention,
It is possible to suppress loss or deterioration of the optical signal due to the 3R processing, and it is possible to effectively use the port.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical cross connect according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the optical cross connect according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining the operation of the optical cross connect according to the embodiment of the present invention.

FIG. 4 is a diagram showing a conventional 3R processing configuration.

[Explanation of symbols]

10 Wavelength converter 20 to 22 3R trunk 31, 41, 42 nodes I1 to I5 input ports O1 to O5 output ports

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kohei Shiomoto             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation (72) Inventor Island Saki             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation (72) Inventor Ya Imajuku             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation (72) Inventor Satoshi Okamoto             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation F-term (reference) 5K069 AA01 BA09 CB01 DA05 DB33                       EA26 EA28                 5K102 AL07 NA02 NA04 NA07 RB11                       RC04

Claims (2)

[Claims] 1. An input port for accommodating an input transmission path to which an optical signal arrives, a wavelength conversion means for converting the wavelength of an optical signal input from this input port into a wavelength corresponding to its destination, and this wavelength conversion. An output port for accommodating an output transmission path for outputting the optical signal whose wavelength is converted by the means, and 3R is provided between at least a part of the output ports and the output transmission path accommodated in the output port. (Reshaping; R
An optical cross connect, characterized in that a means for processing (etiming; Regenerating) is inserted. 2. An optical path network comprising the optical cross connect according to claim 1.