JP3732771B2 - Optical packet routing system and optical packet routing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical packet routing that performs path control (routing) without converting an optical packet signal into an electrical signal by using path control information set in an optical label signal transmitted at a wavelength different from that of the optical packet signal. The present invention relates to a system and an optical packet routing method.
[0002]
[Prior art]
Due to the spread of broadband services to homes, the rapid increase in corporate data communication traffic, and the speeding up of these communication speeds, the construction of a large-capacity communication network has become an urgent task. In order to meet such a demand for an increase in transmission capacity, development of a wavelength division multiplexing (WDM) transmission system that transmits a plurality of optical signals having different wavelengths on a single optical fiber transmission line is in progress. Recently, a WDM transmission system having a multiplexing number of several hundred channels or more and a transmission capacity exceeding 1 Tbps has been reported.
[0003]
By the way, the WDM communication technology can greatly increase the transmission capacity of a communication node between two points. However, when an optical communication network composed of a plurality of communication nodes is constructed, wavelength multiplexing is performed at each communication node. It is necessary to divide the optical signal for each wavelength and to route the data packet in each optical signal for each packet. However, with the increase in transmission speed and capacity, it is considered that the routing processing capacity of enormous data packets reaches the limit in electrical processing.
[0004]
Recently, as a means for solving this problem, a technique for performing routing processing in an optical state (optical layer) without converting an optical packet signal arriving at a communication node or a routing device into an electrical signal has attracted attention. In such an optical packet routing device that performs routing processing of an optical packet signal in the optical layer, it is necessary to obtain path control information of the optical packet signal. As one of them, an optical label signal having a wavelength different from that of the optical packet signal is used. There is a method (different wavelength optical label switching method).
[0005]
FIG. 5 shows a configuration example of a conventional optical packet routing system using a different wavelength optical label switching system. Although the communication node and the optical packet routing device are compatible with each other, only the configuration of the transmission side of the communication node and the configuration of the optical packet routing device corresponding thereto are shown here.
[0006]
In the figure, each communication node 50 includes an optical label signal transmitter 51, an optical packet signal transmitter 52, and an optical multiplexer 53. The optical label signal 41 transmitted from the optical label signal transmitter 51 and the optical packet signal 42 transmitted from the optical packet signal transmitter 52 are wavelength-multiplexed by the optical multiplexer 53 and transmitted to the optical transmission line 1.
[0007]
The optical packet routing device 60 includes an optical demultiplexer 61, an optical label signal receiver 62, an optical label signal transmitter 63, and an optical multiplexer 64 corresponding to each optical transmission path, and further includes a label signal processing unit 65, an optical path, The switch control unit 66 and the optical path switch unit 67 are configured. The optical label signal 41 and the optical packet signal 42 input from the optical transmission line 1 are wavelength-separated by the optical demultiplexer 61, the optical packet signal 42 is input to the optical path switch unit 67, and the optical label signal 41 is the optical label signal. The signal is converted into an electric signal by the receiver 62 and input to the label signal processing unit 65, and the path control information is read. The optical path switch control unit 66 switches the optical path switch unit 67 according to the path control information of each optical label signal, and outputs each optical packet signal to the corresponding output port. Each optical packet signal 42 subjected to routing processing is wavelength-multiplexed with the optical label signal 41 and transmitted to the optical transmission line 1.
[0008]
Since such an optical packet routing system is configured to electrically process only a low-speed optical label signal, it is possible to reduce the burden of routing processing by the electrical signal of the optical packet routing device.
[0009]
[Problems to be solved by the invention]
Incidentally, in the optical packet routing system of FIG. 5, an example in which one optical packet signal and an optical label signal are wavelength-division-multiplexed for each communication node has been shown, but each communication node normally has a plurality of optical packet signals and optical labels. The signal is wavelength-multiplexed and transmitted. For example, as in the communication node shown in FIG. 6, when the optical packet signal transmitters 52-1 to 52-3 transmit optical packet signals having wavelengths λ4 to λ6, respectively, the optical label signal transmitters 51-1 to 51-51. -3 transmits optical label signals of wavelengths λ1 to λ3 corresponding to the optical packet signals. The optical multiplexer 53 multiplexes these six wavelengths and sends them to the optical transmission line 1.
[0010]
Thus, in the conventional optical packet routing system, when optical packet signals of N wavelengths are routed, optical label signals of N wavelengths are required, and a total of 2N wavelengths are required. The utilization efficiency of the wavelength band was low.
[0011]
The present invention relates to an optical packet routing system and an optical packet routing system capable of reducing the number of wavelengths of optical label signals corresponding to a plurality of optical packet signals and increasing the utilization efficiency of the wavelength band of the network in the different wavelength optical label switching system. It aims to provide a method.
[0012]
[Means for Solving the Problems]
The invention according to claim 1 includes a plurality of communication nodes that transmit optical packet signals to a plurality of optical transmission paths, and an optical packet routing device that performs path control of optical packet signals input from the plurality of optical transmission paths. The optical packet routing apparatus propagates through one optical transmission line in an optical packet routing system configured to perform path control based on path control information set in an optical label signal having a wavelength different from that of the optical packet signal. respectively time-division multiplexing each routing information different optical packet signal wavelengths, and transmitted to the optical packet routing device to generate an optical label signal of one wavelength different from the plurality of optical packet signals, the optical packet routing device It is to time division demultiplexing and receiving optical label signal of one wavelength, each based on the routing information of a plurality of optical packet signals Characterized in that it is configured to perform routing control of the packet signal.
[0013]
Here, the one-wavelength optical label signal is configured by bit-multiplexing or frame-multiplexing path control information of a plurality of optical packet signals to be wavelength-multiplexed for each optical transmission line. Thereby, the number of wavelengths of the optical label signal, which conventionally required the number of multiplexed wavelengths of the optical packet signal, can be greatly reduced, and the utilization efficiency of the wavelength band of the network can be increased.
[0014]
The invention according to claim 3, based on the plurality of different optical packet signals with different routing information set in the optical label signal wavelength wavelengths propagating through the optical transmission path, the path control of a plurality of optical packet signals In this optical packet routing method, each path control information of a plurality of optical packet signals is time-division multiplexed, an optical label signal having one wavelength different from the plurality of optical packet signals is generated and transmitted, and an optical label signal having one wavelength is transmitted. Is received and time-division separated, and the path control of each optical packet signal is performed based on each path control information of a plurality of optical packet signals.
[0015]
Here, the one-wavelength optical label signal is configured by bit-multiplexing or frame-multiplexing path control information of an optical packet signal that is wavelength-multiplexed for each optical transmission line. The path control information forming the optical label signal is composed of an Ethernet frame (claim 5).
[0016]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment of optical packet routing system)
FIG. 1 shows an embodiment of an optical packet routing system of the present invention. Although the communication node and the optical packet routing device are compatible with each other, only the configuration of the transmission side of the communication node and the configuration of the optical packet routing device corresponding thereto are shown here as a part related to the present invention. Here, it is assumed that each communication node transmits four optical packet signals.
[0017]
In the figure, each communication node 10 includes packet signal storage units 11-1 to 11-4, optical packet signal transmitters 12-1 to 12-4, a label signal generation unit 13, an optical label signal transmitter 14, and an optical multiplexer. 15 The packet signals input from the packet signal storage units 11-1 to 11-4 to the optical packet signal transmitters 12-1 to 12-4 are transmitted as optical packet signals having wavelengths λ1 to λ4, respectively. The label signal having the path control information of each optical packet signal generated by the label signal generation unit 13 is time-division multiplexed, input to the optical label signal transmitter 14, and transmitted as an optical label signal of wavelength λ5. The optical multiplexer 15 wavelength-multiplexes the optical packet signal having the wavelengths λ1 to λ4 and the optical label signal having the wavelength λ5 and transmits the multiplexed signal to the optical transmission line 1.
[0018]
The optical packet routing device 20 includes an optical demultiplexer 21, an optical label signal receiver 22, an optical label signal transmitter 23, and an optical multiplexer 24 corresponding to each optical transmission path, and further includes a label signal processing unit 25, an optical path, A switch control unit 26 and an optical path switch unit 27 are provided. The optical packet signal having the wavelengths λ1 to λ4 and the optical label signal having the wavelength λ5 input from the optical transmission line 1 are wavelength-separated by the optical demultiplexer 21, and the optical packet signal is input to the optical path switch unit 27. Is converted into an electrical signal by the optical label signal receiver 22 and input to the label signal processing unit 25. The label signal input to the label signal processing unit 25 is time-division-separated , reconfigured into a label signal corresponding to each optical packet signal, and each path control information is read. The optical path switch control unit 26 switches the optical path switch unit 27 according to the path control information corresponding to each optical packet signal, and outputs each optical packet signal to the corresponding output port.
[0019]
On the other hand, the label signal processing unit 25 time-division-multiplexes the label signal having the path control information of the optical packet signal to be wavelength-multiplexed for each optical transmission path, and inputs it to the optical label signal transmitter 23 to convert it into an optical label signal. Is done. The optical label signal transmitted from the optical label signal transmitter 23 and the optical packet signal of each wavelength routed by the optical path switch unit 27 are wavelength multiplexed by the optical multiplexer 24 and transmitted to the optical transmission line 1. .
[0020]
As described above, in the optical packet routing system of the present invention, each path control information for a plurality of optical packet signals having different wavelengths is time-division multiplexed to be transmitted as an optical label signal having one wavelength different from the optical packet signal. be able to. As a result, in the example of FIG. 1, it becomes possible to cope with four optical packet signals with one optical label signal, and greatly reduces the number of wavelengths of the optical label signal required in the different wavelength optical label switching method. In addition, the utilization efficiency of the wavelength band of the network can be increased.
[0021]
The optical multiplexer 15 of the communication node 10, as an optical demultiplexer 21 and optical multiplexer 24 of the optical packet routing device 20 may use an array waveguide diffraction grating (AWG).
[0022]
(First configuration example of the label signal generation unit 13)
FIG. 2 shows a first configuration example of the label signal generation unit 13. The packet signal storage units 11-1 to 11-4, the optical packet signal transmitters 12-1 to 12-4, the optical label signal transmitter 14, and the optical multiplexer 15 are the same as the respective units shown in FIG. is there.
[0023]
In FIG. 2, the label signal generation unit 13 includes path control information output units 31-1 to 31-4 that output path control information 30-1 to 30-4 of each optical packet signal, and each path control information 30-1. ˜30-4 are configured by a time division multiplexing unit 32 that performs time division multiplexing. Here, each path control information 30-1 to 30-4 is expressed by 4 bits, and each bit is distinguished by being attached with a, b, c, d.
[0024]
The time division multiplexing unit 32 in this configuration example is configured to bit-multiplex the route control information 30-1 to 30-4, and outputs thereof are 30-1a, 30-2a, 30-3a, 30-4a, 30-. 1b,... If each bit width of the routing information 30-1 to 30-4 is T, each bit width of the bit-multiplexed routing control information 30-1a to 30-4d is T / 4. The path control information corresponding to each optical packet signal bit-multiplexed in this way is converted into an optical label signal of wavelength λ5 by the optical label signal transmitter 14 and transmitted.
[0025]
(Second configuration example of the label signal generation unit 13)
FIG. 3 shows a second configuration example of the label signal generation unit 13. The packet signal storage units 11-1 to 11-4, the optical packet signal transmitters 12-1 to 12-4, the optical label signal transmitter 14, and the optical multiplexer 15 are the same as the respective units shown in FIG. is there.
[0026]
In FIG. 3, the label signal generating unit 13 includes path control information output units 31-1 to 31-4 that output path control information 30-1 to 30-4 of each optical packet signal, and each path control information 30-1. ˜30-4 are configured by a time division multiplexing unit 32 that performs time division multiplexing. Here, each path control information 30-1 to 30-4 is assumed to be a frame signal composed of 4 bits.
[0027]
The time division multiplexing unit 32 in this configuration example is configured to frame-multiplex the path control information 30-1 to 30-4, and outputs thereof are 30-1, 30-2, 30-3, and 30-4. The path control information corresponding to each optical packet signal thus frame-multiplexed is converted into an optical label signal of wavelength λ5 by the optical label signal transmitter 14 and transmitted.
[0028]
(Third configuration example of the label signal generation unit 13)
FIG. 4 shows a third configuration example of the label signal generation unit 13.
In the figure, when the path control information output units 31-1 to 31-4 and the time division multiplexing unit 32 constituting the label signal generation unit 13 are connected via an optical interface, the path control information output unit 31-1 ˜31-4 electrical / optical converters (E / O) 33-1 to 33-4 and time division multiplexing unit 32 optical / electrical converters (O / E) 34-1 to 34-4 Are connected via optical transmission lines 35-1 to 35-4. Thereby, the path control information output from the path control information output units 31-1 to 31-4 is once converted into an optical signal, converted into an electric signal again, and input to the time division multiplexing unit 32. .
[0029]
Note that the protocol of the path control information output from the path control information output units 31-1 to 31-4 of the label signal generation unit 13 described above may be an Ethernet protocol, an ATM protocol, or other protocols.
[0030]
【The invention's effect】
As described above, the optical packet routing system and the optical packet routing method of the present invention use a single-wavelength optical label signal for each optical transmission line to obtain path control information for a plurality of wavelength-multiplexed optical packet signals. Division multiplexing (bit multiplexing, frame multiplexing) transmission can be performed. Thereby, the number of wavelengths of the optical label signal, which conventionally required the number of multiplexed wavelengths of the optical packet signal, can be greatly reduced, and the utilization efficiency of the wavelength band of the network can be increased.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of an optical packet routing system of the present invention.
FIG. 2 is a block diagram illustrating a first configuration example of a label signal generation unit 13;
FIG. 3 is a block diagram illustrating a second configuration example of the label signal generation unit 13;
FIG. 4 is a block diagram showing a third configuration example of the label signal generation unit 13;
FIG. 5 is a block diagram showing a configuration example of a conventional optical packet routing system using a different wavelength optical label switching system.
FIG. 6 is a block diagram showing a configuration example of a communication node in a conventional optical packet routing system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical transmission line 10 Communication node 11 Packet signal storage part 12 Optical packet signal transmitter 13 Label signal generation part 14 Optical label signal transmitter 15 Optical multiplexer 20 Optical packet routing apparatus 21 Optical demultiplexer 22 Optical label signal receiver 23 Optical label signal transmitter 24 Optical multiplexer 25 Label signal processing unit 26 Optical path switch control unit 27 Optical path switch unit 30 Path control information 31 Path control information output unit 32 Time division multiplexing unit 33 Electric / optical converter (E / O) )
34 Optical / electrical converter (O / E)
35 Optical transmission line

Claims (5)

A plurality of communication nodes that transmit optical packet signals to a plurality of optical transmission lines; and an optical packet routing device that performs path control of optical packet signals that are input from the plurality of optical transmission lines. In an optical packet routing system that is configured to perform path control based on path control information set in an optical label signal having a wavelength different from that of the optical packet signal,
One each routing information of a plurality of optical packet signals respectively different wavelengths propagating through the optical transmission path time division multiplexing, the optical packet to generate an optical label signal of one wavelength different from the plurality of optical packet signals To the routing device,
The optical packet routing device is configured to receive the optical label signal of one wavelength and perform time-division separation , and perform path control of each optical packet signal based on each path control information of the plurality of optical packet signals. An optical packet routing system characterized by The optical packet routing system according to claim 1,
The optical packet routing system according to claim 1, wherein the one-wavelength optical label signal is configured by bit-multiplexing or frame-multiplexing path control information of a plurality of optical packet signals that are wavelength-multiplexed for each optical transmission line. In an optical packet routing method for performing path control of the plurality of optical packet signals based on path control information set to a plurality of optical packet signals having different wavelengths and optical label signals having different wavelengths respectively propagating through an optical transmission line,
Each path control information of the plurality of optical packet signals is time-division multiplexed, and an optical label signal having one wavelength different from the plurality of optical packet signals is generated and transmitted.
An optical packet routing method, comprising : receiving the optical label signal of one wavelength, performing time division separation , and performing path control of each optical packet signal based on each path control information of the plurality of optical packet signals. The optical packet routing system according to claim 3.
The optical packet routing method according to claim 1, wherein the one-wavelength optical label signal is configured by bit-multiplexing or frame-multiplexing path control information of an optical packet signal that is wavelength-multiplexed for each optical transmission line. In the optical packet routing system according to claim 3 or 4,
The optical packet routing method, wherein the path control information forming the optical label signal is composed of an Ethernet (registered trademark) frame.

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