JP3468190B2 - WDM optical subscriber transmission system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength division multiplexing optical subscriber transmission system, and more particularly to an optical subscriber line terminating unit (ONU) in an optical subscriber transmission system using the wavelength division multiplexing system.
The present invention relates to a wavelength division multiplex optical subscriber transmission system characterized by efficiently transmitting packets by preliminarily allocating fixed optical wavelengths.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 3-44701, which is cited as a first prior art, modulates output lights of a plurality of light sources having different optical frequencies by respective information signals from a plurality of corresponding signal sources. Among the plurality of modulated light waves transmitted by the one optical fiber transmission line, a center-side device formed so as to photosynthesize the plurality of modulated light waves to be coupled to one optical fiber transmission line One of the two is formed by a tunable optical demultiplexer capable of adjusting the pass band, the selected modulated light wave is detected, and the corresponding information signal is taken out as an electric signal. A broadband optical information transmission system including a person-side device is disclosed.

A technique similar to that of the first conventional example is described in "Introduction to Optical Fiber Communication" (Yasuharu Suematsu, Kenichi Iga,
"Ohm Co., Ltd., January 30, 1997)", page 242.

As a second conventional example, Japanese Patent Laid-Open No. 8-
Japanese Patent No. 234250 discloses a pumping pulse light source that outputs a pumping light pulse having a wavelength λo, a pumping light pulse that has a predetermined length, dispersion slope, and dispersion in a wavelength range Δλ including the wavelength λo. Coherent white light source including a nonlinear optical medium that outputs ultra-wide band coherent white light, an arrayed waveguide optical multiplexer / demultiplexer having N input ports and N output ports, and N-1 outputs The optical pulse demultiplexed to the port is modulated and the modulated signal light of each wavelength is N-1.
N-1 optical modulators respectively input to the corresponding input ports, coherent white light is input to one input port of the arrayed waveguide optical multiplexer / demultiplexer, and wavelength multiplexing is performed from one output port. A wavelength-multiplexed signal light generation device that outputs signal light is disclosed. However, this second conventional example is merely an apparatus for collectively generating a plurality of ultrashort pulse signals in a wide wavelength range.

[0005]

However, since the packet processing according to the above prior art is performed only by electrical processing, such electrical processing has a limit in improving the packet processing capability. In addition, there is a problem in that, if an attempt is made to improve the packet processing capability, a high speed electric circuit is required and power consumption increases.

In view of the above-mentioned conventional circumstances, the present invention has been made to solve the above-mentioned drawbacks inherent in the prior art. Therefore, the object of the present invention is to provide an optical subscriber transmission system using a wavelength multiplexing system. , Optical subscriber line termination device (ON
It is to provide a novel wavelength division multiplexing optical subscriber transmission system capable of improving packet processing capability by fixedly assigning an optical wavelength to U).

[0007]

To achieve the above object, a wavelength division multiplexing optical subscriber transmission system according to the present invention comprises a packet analysis means for inputting a transmission packet and analyzing a destination address of the transmission packet, A control means to which the destination address analyzed by the analyzing means is supplied, a white noise light source whose optical output spectrum has a flat characteristic in the entire optical wavelength band, and the transmission packet which is inputted and the white noise is generated by the transmission packet. A light source driving means for driving the light source, an AWG supplied with the output of the light source driving means and generating a narrow band optical output spectrum at equal intervals, and the control means arranged corresponding to each output of the AWG. That "ON", "OF
Corresponding to a plurality of optical switches whose F "is controlled, an optical coupler for wavelength-multiplexing the outputs of the optical switches and sending them to an optical transmission line, and an optical coupler for receiving a transmission packet from the optical transmission line. And a plurality of optical subscriber line terminating devices provided as described above.

In each of the optical switches, only the optical switch corresponding to the optical wavelength indicated by the destination of the transmission packet is "ON".
To be

In each of the optical switches, only the optical switch connected to the wavelength corresponding to the destination address of the transmission packet is turned on by the control means, and the other optical switches are turned off. Controlled as.

The present invention is characterized in that an optical wavelength is fixedly assigned to the optical subscriber line terminating device, and the optical wavelength of the transmission packet is changed for each destination.

Each of the optical subscriber line terminal devices has its own optical wavelength optical filter and optical receiving means.

[0012]

In FIG. 1, as an example, consider an eight-wave multiplexing optical subscriber transmission system in which eight optical subscriber line termination units (ONUs) are connected, and wavelengths are fixedly assigned to each of ONU1 to ONU8 of ONU9. It is assumed that

The transmission packet 1 is input to the destination analysis unit 2, the destination address of the transmission packet 1 is analyzed, and the analyzed destination address is sent to the control unit 6.

On the other hand, the transmission packet 1 is input to the light source drive circuit 3, and the white noise light source 4 is driven by the transmission packet 1.
The optical output spectrum of the white noise light source 4 at that time is shown in FIG.
It has a flat characteristic in the entire optical wavelength band as shown in (a).

The output of the white noise light source 4 is changed to AWG (Aray).
Enter in Waveguide Grating 5).

Since the AWG 5 is an optical wavelength filter having an equal interval and a narrow band, the optical output spectrum of the AWG 5 is shown in FIG.
The characteristic is such that a spectrum as shown in (b) appears.

Each port output of the AWG 5 is input to the optical SW 7 connected to each port. Each light SW
The control unit 6 turns on only those connected to the wavelength corresponding to the destination address of the transmission packet 1 by the control unit 6,
Others are controlled to be "OFF".

The output of each optical SW 7 is the optical coupler 8
Is input to the optical fiber, is wavelength-division multiplexed, and is output to the optical transmission line.

By the above control, the transmission packet 1 is transmitted from the station device as an optical signal having an optical wavelength different depending on its destination. The ONU 9 can receive only a packet addressed to itself by previously mounting a dedicated optical filter.

Therefore, the electric filtering circuit in the ONU 9 is not required, and the optical signal is filtered as it is, so that the packet processing capability is improved.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Structure of Embodiment] In FIG. 1, a destination analysis unit 2 receives a transmission packet 1 and transmits the transmission packet 1.
The destination address is analyzed and the analyzed destination address is sent to the control unit 6. The light source drive circuit 3 drives the white noise light source 4 with the transmission packet 1. The output of the white noise light source 4 is AWG
Input to 5. Since the AWG 5 is an optical wavelength filter having an equal interval and a narrow band, the optical output spectrum of the AWG 5 has a characteristic that a spectrum as shown in FIG. 2B appears.

The output of the AWG 5 is input to the optical SW 7 connected to each port. Each light SW7
Is controlled by the control unit 6 so that only those connected to the wavelength corresponding to the address of the transmission packet 1 are turned “ON” and the others are turned “OFF”.

Each output of the optical SW 7 is an optical coupler 8
Is input to the optical transmission line 13 and the output of the optical coupler 8 is output to the optical transmission line 13.

In the ONU (optical subscriber line terminating device) 9, the optical signal from the optical coupler 8 is input to the built-in optical filter 10, and the output of the optical filter 10 is input to the optical receiving circuit 11.

[Operation of the Embodiment] Next, the operation of the embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, as an example, consider an 8-wave multiplexing optical subscriber transmission system in which eight optical subscriber line terminating units (ONUs) are connected, and it is assumed that wavelengths are fixedly assigned to each ONU. To do.

Referring to FIGS. 1 and 2, a transmission packet 1
To the destination analysis unit 2 to analyze the destination address of the transmission packet 1 and send the analyzed destination address to the control unit 6.

On the other hand, the transmission packet 1 is input to the light source drive circuit 3, and the white noise light source 4 is driven by the transmission packet 1.
The optical output spectrum of the white noise light source 4 at that time is shown in FIG.
It has a flat characteristic in the entire optical wavelength band as shown in (a).
The output of the white noise light source 4 is changed to AWG (Array Waveg).
input Grating 5).

Since the AWG 5 is an optical wavelength filter having an equal interval and a narrow band, the optical output spectrum of the AWG 5 has a characteristic that a spectrum as shown in FIG. 2B appears.

The respective port outputs λ1 to λ8 of the AWG 5 are input to the optical SW7 connected to the respective ports.

Each optical SW 7 is controlled by the control unit 6 so that only the one connected to the wavelength corresponding to the address of the transmission packet 1 is turned "ON", and the others are turned "OFF". The output of each light SW 7 is input to the optical coupler 8, wavelength-multiplexed with the light, and sent out to the optical transmission line 13.

By the above control, the transmission packet 1 becomes an optical signal whose optical wavelength differs depending on its destination, and the station device 12
Sent from.

The ONU 9 can receive only a packet addressed to itself by previously mounting a dedicated optical filter.

[0036]

As described above, according to the present invention,
In the optical subscriber transmission system using the wavelength division multiplexing method,
By permanently allocating the optical wavelength to the optical subscriber line terminating device (ONU), the electric filtering circuit in the ONU is not required, and the optical signal is filtered, so that the packet processing capability is improved. Is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment according to the present invention.

2A and 2B are diagrams for explaining the operation of the embodiment according to the present invention.

[Explanation of symbols]

1 ... Transmission packet 2 ... Destination analysis unit 3 ... Light source drive circuit 4 ... White noise light source 5 ... AWG 6 ... Control unit 7 ... Optical SW 8 ... Optical coupler 9 (ONU1 to 8) ... Optical subscriber line terminating device (ONU) 10 ... Optical filter 11 ... Optical receiver circuit 12 ... Station device 13 ... Optical transmission line

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04L 12/44 H04B 10/00-10/28 H04J 14/00-14/08 JISST file (JOIS)

Claims (5)

(57) [Claims] 1. A packet analysis means for inputting a transmission packet and analyzing a destination address of the transmission packet, a control means for supplying the destination address analyzed by the analysis means, and an optical output spectrum thereof having an all-optical wavelength. A white noise light source having a flat characteristic in a band, a light source driving unit for inputting the transmission packet and driving the white noise light source by the transmission packet, and an output of the light source driving unit are supplied, and a narrow band of equal width is provided. An AWG that generates an optical output spectrum and the A
A plurality of optical switches which are arranged corresponding to the respective outputs of the WG and whose "ON" and "OFF" are controlled by the control means, and the outputs of the optical switches are wavelength-division multiplexed and sent to the optical transmission line. Optical coupler transmission, and a plurality of optical subscriber line terminating devices provided corresponding to the optical coupler for receiving a transmission packet from the optical transmission line. method. 2. In each of the optical switches, only the optical switch corresponding to the optical wavelength indicated by the destination of the transmission packet is “O”.
The wavelength division multiplexing optical fiber subscriber transmission system according to claim 1, further characterized by being set to N ". 3. In each of the optical switches, only the optical switch connected to the wavelength corresponding to the destination address of the transmission packet is turned on by the control means, and the other optical switches are turned off. The WDM optical transmission system according to claim 1, further characterized by being controlled as follows. 4. The optical wavelength is fixedly assigned to the optical subscriber line terminating device, and the optical wavelength of the transmission packet is changed for each destination. WDM optical transmission system described. 5. The optical subscriber line terminating device according to claim 1, further comprising an optical filter for an optical wavelength unique to each of the optical subscriber line terminating devices and an optical receiving means. WDM optical transmission system described.