Optical transmission apparatus

• US 8,401,386 B2
• Filed: 03/30/2010
• Issued: 03/19/2013
• Est. Priority Date: 04/09/2009
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Izumi, Futoshi
• Primary Examiner(s): Vanderpuye, Kenneth N
• Assistant Examiner(s): SANDHU, AMRITBIR K
• Application Number:
  US12/749,610
• Publication Number:
  US 20100260499A1
• Time in Patent Office: 1,085 Days
• Field of Search: 398/48, 398/69, 398/33
• US Class Current: 398/48
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0307 Multiplexers; Demultiplexers
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring

Abstract

There is provided an optical transmission apparatus including: a plurality of wavelength selective switches including input ports, a transmission port, and monitor port used to output a light switched so that the light from the input port is monitored; a multiplexer to combine the lights output from the transmission ports of the plurality of wavelength selective switches; a monitor to monitor whether a same wavelength of the light output from the monitor port exists in wavelengths of the lights combined by the multiplexer; and a controller to control the wavelength selective switch so as to output, from the transmission port, the light switched to the monitor port in case that the same wavelength of the light output from the monitor port is absent in wavelengths of the lights combined by the multiplexer, based on a monitor result by the monitor.

Claims

1. An optical transmission apparatus comprising:

a plurality of wavelength selective switches, each including input ports, a transmission port used to output a wavelength multiplexed light containing input light from the input ports that is switched and multiplexed, and a monitor port used to output a monitored light switched from one of the input ports, so that the input light is monitored;

a multiplexer to combine wavelength multiplexed lights output from the transmission ports of the plurality of wavelength selective switches;

a monitor to monitor whether a same wavelength of the monitored light output from the monitor port exists in wavelengths of the wavelength multiplexed lights combined by the multiplexer; and

a controller to control each of the wavelength selective switches so as to output, from the transmission port, the monitored light switched to the monitor port only when the same wavelength of the monitored light is absent from the wavelengths of the wavelength multiplexed lights combined by the multiplexer prior to receipt of the monitored light, based on a monitor result output by the monitor, and when the monitored light replaces a same wavelength light input to another of the wavelength selective switches.

2. The optical transmission apparatus according to claim 1, further comprising:

a light detection unit to output a detection signal used to indicate a detection of a light input to the input port;

wherein the controller controls each of the wavelength selective switches so as to output the light input to the input port from the monitor port in case that the controller receives the detection signal.

3. The optical transmission apparatus according to claim 1, wherein the controller controls each of the wavelength selective switches so that the input port is connected to the monitor port at a constant cycle, the input port being unused for a wavelength addition.

5. The optical transmission apparatus according to claim 1,

wherein, in case that the monitor detects disconnection of the light of a wavelength in the light combined by the multiplexer, the controller controls the wavelength selective switch so as to disconnect a path which is established between the input port where the light of the disconnected wavelength was input and the transmission port, and

in case that the controller determines subtraction has been set for a wavelength of a light in lights combined by the multiplexer, the controller controls the wavelength selective switch so as to disconnect a path which is established between the input port input where the light of the subtracted wavelength was input and the transmission port.

6. The optical transmission apparatus according to claim 1,

wherein, in case that a path from the input port to the transmission port is established, the wavelength selective switch stepwise decreases an attenuation amount of the light, and

in case that the path from the input port to the transmission port is disconnected, the wavelength selective switch stepwise increases the attenuation amount of the light.

4. An optical transmission apparatus comprising:

a plurality of wavelength selective switches, each including input ports, a transmission port used to output a wavelength multiplexed light containing input light from the input ports that is switched and multiplexed, and a monitor port used to output a monitored light switched from one of the input ports, so that the input light is monitored;

a multiplexer to combine wavelength multiplexed lights output from the transmission ports of the plurality of wavelength selective switches;

a monitor to monitor whether a same wavelength of the monitored light output from the monitor port exists in wavelengths of the wavelength multiplexed lights combined by the multiplexer; and

a controller to control each of the wavelength selective switches so as to disconnect a first path which is established between a first input port and the transmission port, when currently transmitted light having the same wavelength as newly added light is being transmitted on the first path, in a case where the currently transmitted light being combined by the multiplexer is replaced with the newly added light to disconnect a second path which is established between a second input port and the monitor port, in a case where the currently transmitted light combined by the multiplexer is not replaced with the newly added light.

7. An optical transmission apparatus comprising:

a controller;

a plurality of wavelength selective switches, each including input ports, and a transmission port used to output a wavelength multiplexed light containing input light from the input ports that is switched and multiplexed;

a monitor switch including a plurality of input ports for monitor being respectively connected to the input ports, and a monitor port used to output a light switched so that the light from the input port is monitored, the monitor switch of each wavelength selective switch being arranged, the monitor switch outputting a light input from the input port and received via the input port for monitor from the monitor port based on control of the controller;

a multiplexer to combine wavelength multiplexed lights output from the transmission ports of the plurality of wavelength selective switches; and

a monitor to monitor whether a same wavelength of the monitored light output from the monitor port exists in wavelengths of the wavelength multiplexed lights combined by the multiplexer;

wherein the controller controls each of the wavelength selective switches so as to output, from the transmission port, the monitored light switched to the monitor port only when the same wavelength of the monitored light is absent from the wavelengths of the wavelength multiplexed lights combined by the multiplexer prior to receipt of the monitored light and when the monitored light replaces a same wavelength light input to another of the wavelength selective switches.

8. An optical transmission apparatus comprising:

a controller;

an optical cross connect switch including input ports, a transmission port used to output a wavelength multiplexed light containing input light from the input ports that is switched and multiplexed, and a monitor port used to output a monitored light switched from one of the input ports, so that the input light is monitored, the optical cross connect switch outputting a light input from the input port from the monitor port based on control of the controller;

a multiplexer to combine wavelength multiplexed lights output from the transmission ports of the optical cross connect switch; and

a monitor to monitor whether a same wavelength of the monitored light output from the monitor port exists in wavelengths of the wavelength multiplexed lights combined by the multiplexer;

wherein the controller controls the optical cross connect switch so as to output, from the transmission port, the light switched to the monitor port in case that the same wavelength of the light output from the monitor port is absent in wavelengths of the lights combined by the multiplexer,

wherein, in case that the monitor detects disconnection of the light of a wavelength in the light combined by the multiplexer, the controller controls the optical cross connect switch so as to disconnect a path which is established between the input port where the light of the disconnected wavelength was input and the transmission port, and

wherein, in case that the controller determines subtraction has been set for a wavelength of a light in lights combined by the multiplexer, the controller controls the optical cross connect switch so as to disconnect a path which is established between the input port input where the light of the subtracted wavelength was input and the transmission port.

9. The optical transmission apparatus according to claim 8,

when the monitor determines that the same wavelength of the light output from the monitor port exists in wavelengths of the lights combined by the multiplexer,

wherein the controller controls the optical cross connect switch so as to block a light of a wavelength disconnected, and the optical cross connect switch connects the input port in which the light of the wavelength disconnected is input with an output port unused.

10. The optical transmission apparatus according to claim 8, further comprising:

a light detection unit to output a detection signal used to indicate a detection of a light input to the input port;

wherein the controller controls the optical cross connect switch so as to output the light input to the input port from the monitor port in case that the controller receives the detection signal.

11. The optical transmission apparatus according to claim 8, wherein the controller controls the optical cross connect switch so that the input port is connected to the monitor port at a constant cycle, the input port being unused for a wavelength addition.