JP2010193032A - Power saving optical transceiver, method thereof and optical transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an optical transceiver capable of achieving power saving while securing the link connection properties of a network. <P>SOLUTION: When setting a sleep mode in the optical transceiver, power supply to an interface modulation part and a data processing part which may require much power consumption is turned off to achieve power saving. Further, a line connection state between nodes is monitored by using continuous light output by the power-off to secure the reliability of network. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power-saving optical transmission / reception device, method, and optical transmission system. More specifically, the present invention relates to an optical transmission / reception apparatus, a method thereof, and an optical transmission system including the optical transmission / reception apparatus in which power saving and link connectivity are highly reliable.

  In the current optical network, the interface is always used at full power regardless of the traffic volume. For example, in a 10 Gbps transponder, the actual data flows only about 1 Gbps, but the transponder operates at full power. Also, during daytime business hours during the day, there is a lot of traffic, and it is used at full power all day even though there is little traffic at midnight. Therefore, there is a problem that power is wasted in an interface with a small amount of traffic. As an attempt to solve this problem, in Non-Patent Document 1, studies are underway to reduce power consumption by optimizing port power according to the amount of traffic. However, since Non-Patent Document 1 is currently under consideration for standardization, no formal document has been released. In Non-Patent Document 2, a method of reducing power consumption by putting an interface to sleep according to the amount of traffic has been studied.

IEEE802.1az, "Energy Efficient Ethernet" M. Gupta and S. Singh, "Greening of the Internet," Proc. ACM SIGCOMM'03, August 2003.

  However, in Non-Patent Document 1, only studies relating to electrical signal communication are underway, and no studies relating to optical signals are made. Non-Patent Document 2 assumes application to the edge region of a network, for example, a small-scale network such as a campus network or a corporate network, and does not consider application to a core / metro network. .

  Even in the optical transmission system of the core / metro network, it is possible to suppress wasteful power consumption by turning off the interface power during the time when traffic does not flow by applying the method as described in Non-Patent Document 2. . However, in this case, since an optical signal is not transmitted from the optical transmitter, there is no means for confirming link connectivity with the opposite device, and the reliability of the network is lowered. For example, if a link failure with a link with the opposite device occurs while the interface is powered off, the link connectivity cannot be confirmed. When the interface is turned on assuming that the link is connected, communication is disconnected because the link connectivity is actually lost, and the service cannot be provided.

  Japanese Laid-Open Patent Publication No. 2006-196938 proposes a method for confirming the connectivity of unused links using monitoring light or ASE (Amplitude Spontaneous Noise). In this method, monitoring is performed using dummy light. Since it does not monitor the wavelengths and ports that are actually used, it cannot be said that ensuring network reliability is sufficient.

  Therefore, an object of the present invention is to realize an optical transmission / reception apparatus, method, and optical transmission system that can save power while ensuring link connectivity of a network.

  In order to achieve the above object, an optical transmission / reception apparatus according to the present invention comprises an optical transmission / reception apparatus having a transmitter and a receiver, wherein the output light of the transmitter is continuous light that is not modulated, and the receiver. Setting means for setting the alarm mask and monitoring means for monitoring the optical power of the input light of the receiver.

  Further, the output means is means for turning off the power of the modulator driver and the data processing section of the transmitter, and the monitoring means is turned off of the clock extraction section and the data processing section of the receiver, and the continuous light It is also preferable to be a means for determining the occurrence of a link failure based on the optical power of.

  Further, it is also preferable that the output means is executed when no traffic flows to the transmitter, and the setting means and the monitoring means are executed when the transmitter of the opposite device executes the output means. .

  In order to achieve the above object, a method for saving power in an optical transceiver according to the present invention is a method for saving power in an optical transceiver having a transmitter and a receiver, wherein the output light of the transmitter is modulated. An output step for making continuous light not performed, a setting step for setting an alarm mask of the receiver, and a monitoring step for monitoring the optical power of the input light of the receiver.

  In order to achieve the above object, an optical transmission system according to the present invention includes an optical transmission / reception apparatus having a transmitter and a receiver, and an optical transmission path connecting the apparatuses. Means for notifying the receiver of the sleep mode, output means for making the output light of the transmitter continuous light that is not modulated, setting means for setting an alarm mask of the receiver of the opposite device, A sleep mode setting means comprising: monitoring means for monitoring the optical power of the input light of the receiver of the opposite device; and means for receiving a setting completion notification from the receiver of the opposite device to the transmitter; Output means for converting the output light into modulated light, means for the transmitter to notify the receiver of the opposite device that the sleep mode is restored, and release the alarm mask of the receiver of the opposite device A sleep mode comprising: determining means; ending means for ending monitoring of the optical power of the input light of the receiver of the opposite apparatus; and means for the receiver of the opposite apparatus to notify the transmitter of setting completion Recovery means.

  According to the present invention, it is possible to monitor the link connectivity with the opposite device while realizing power saving of the optical transmission / reception device, thereby realizing a power saving and highly reliable network.

1 shows an outline of an optical transmission system including an optical transceiver according to the present invention. 1 shows a configuration of an optical transceiver according to the present invention. The sleep of a one-way interface and the recovery procedure from a sleep state are shown. The sleep of a bidirectional | two-way interface and the recovery procedure from a sleep state are shown.

  The best mode for carrying out the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an outline of an optical transmission system composed of an optical transceiver according to the present invention. FIG. 1a shows an optical transmission system in which monitoring light is used for communication of information between opposing devices. FIG. 1B shows an optical transmission system in which an optical transceiver is controlled by a network management system connected to a control / management network.

  The optical transmission system includes an optical transmission / reception device, an optical transmission line, and an optical amplifier, and further includes a control / management network and a network management system in the form of FIG. 1B. Communication between optical transceivers is performed using an optical transmission line, and an optical amplifier for amplifying light is provided in the optical transmission line. The network management system monitors links between optical transmission / reception apparatuses via a control / management network.

  The optical transmission / reception apparatus includes a plurality of optical transceivers and an optical multiplexing / demultiplexing unit, and further includes a part for transmitting and receiving monitoring light in the form of FIG. 1a. The monitoring light is used for communication between the optical transmitting and receiving apparatuses, and is used when a control / management network is not provided as shown in FIG. 1a. The optical transceiver modulates an electrical signal into light, and reversely restores the modulated light into an electrical signal. The optical multiplexing / demultiplexing unit multiplexes the light from the optical transceiver and sends it to the optical transmission line, and demultiplexes the light from the optical transmission line and sends it to the optical transceiver.

  FIG. 2 shows the configuration of an optical transceiver according to the present invention. 2a and 2b show a transmitter. FIG. 2 shows an example in which one modulator is used. FIG. 2b shows an example where a plurality of modulators are used. FIG. 2b performs phase modulation in addition to data modulation for long distance transmission and includes two modulators. FIG. 2c shows the receiver.

  The transmitter of the optical transceiver includes a light source 1, a data modulator 2, a modulator driver 3, a data processing unit 4, a bias power supply 5, and a client side transponder 6. Further, a phase modulator 7 and a modulator driver 3 for driving the phase modulator 7 can be further provided. The receiver of the optical transceiver includes an optical-electric conversion unit 8, a clock extraction unit 9, a data processing unit 4, and a client side transponder 6.

  The light source 1 is a signal light source, the data modulator 2 is a part that modulates an electrical data signal into an optical signal, and the modulator driver 3 is an electrical signal amplifier for driving the data modulator 2. The data processing unit 4 is a part that performs encapsulation processing and encapsulation removal processing on a client signal with a digital wrapper (for example, an OTN signal). The client-side transponder 6 is a part for converting a client signal into an electric signal. The phase modulator 7 is a modulator used for long distance transmission. The clock extraction unit 9 is a part that extracts a clock from the received optical signal. The OTN (Optical Transport Network) signal is an ITU-T recommendation G.264. 709 shows a signal standard based on "Interfaces for the Optical Transport Network".

  In the optical transmission / reception apparatus as described above, an interface (transmitter or receiver) through which no traffic flows is put to sleep. In this case, power saving is realized by turning off the power of the modulation unit and the data processing unit 4 of the interface with high power consumption. The modulation unit of the interface includes a modulator driver 3 and a bias power source 5 for the modulator. In the case of an optical transceiver including a plurality of modulators, all of the modulator drivers 3 and the modulation bias power supply 5 connected to the modulators are included. For example, the configuration of FIG. 2 b includes a data modulator 2, a modulator driver 3 connected to the phase modulator 7, and a bias power supply 5. Also, when the modulator driver 3 of the interface is turned off, the output from the optical transmitter becomes continuous light that is not modulated. By using the continuous light, the link connection state between the nodes is monitored. Ensuring network reliability. Therefore, the power source of the light source 1 necessary for transmitting / receiving continuous light is not turned off.

  FIG. 3 shows a one-way interface sleep and a recovery procedure from the sleep state. FIG. 3 shows a case in which monitoring light is used for command communication between a transmitter and a receiver, and a one-way interface is put to sleep as shown in FIG. When the control / management network is used for command communication as shown in FIG. 1b, the command is received by the network management system instead of the monitoring light, but the procedure itself is the same as in FIG. Become.

First, when the interface is set to the sleep mode, the following procedure is performed.
S1. The transmitter notifies the opposite device that the interface is set to the sleep mode.
S2. The receiver that has received the notification of the sleep mode sets an alarm mask so that an alarm is not transmitted even if the data signal (this data signal is a signal framed by the OTN signal) is interrupted. Thereafter, the data processing unit 4 and the clock extraction unit 9 are powered off. Furthermore, the received optical power is monitored.
S3. The receiver returns a notification of setting completion to the transmitter.
S4. The transmitter turns off the power to the modulator driver 3 and the data processing unit 4 after confirming the setting completion notification from the opposite device. Thereby, a transmitter will be in a continuous light transmission state.

Next, when the interface is released from the sleep mode, the following procedure is performed.
S5. The transmitter turns on the power of the modulator driver 3 and the data processing unit 4 when canceling the sleep mode.
S6. The transmitter notifies the opposite device of the recovery of the sleep mode.
S7. After receiving the notification in S6, the receiver turns on the data processing unit 4 and the clock extraction unit 9.
S8. The receiver cancels the alarm mask setting after confirming reception of the data signal.
S9. The receiver notifies the completion of setting. This setting completion notification is necessary in order to avoid silent failure.

  In the above procedure, the operation when a failure occurs is as follows. If the transmitter cannot confirm the notification of the completion of setting in S3 or the notification of completion of the setting in S9, it is determined as a failure and the setting of each device is returned to the state before the setting. In S3, the transmitter keeps the power of the modulator driver 3 and the data processing unit 4 turned on, and in S9, the transmitter turns off the power of the modulator driver 3 and the data processing unit 4.

  If S4 or S5 cannot be set, the transmitter notifies the receiver to that effect.

  Also, in the optical power monitoring at the receiver, an alarm is given as a link failure when the measured value falls below a set threshold value.

  FIG. 4 shows the sleep of the bidirectional interface and the recovery procedure from the sleep state. FIG. 4 also shows a case where supervisory light is used for command communication between the transmitter and the receiver, as in FIG. 1a. When the control / management network is used for command communication as shown in FIG. 1b, the command is received by the network management system instead of the monitoring light, but the procedure itself is the same as in FIG.

First, when the interface is set to the sleep mode, it is as follows.
S1. When the transmitter / receiver (A) enters the sleep mode, the alarm mask of the receiver is set, and then the clock extraction unit 9 and the data processing unit 4 of the receiver are turned off. In addition, the optical power of the receiver is monitored.
S2. The transceiver (A) notifies the opposite device that the interface is set to the sleep mode.
S3. The transceiver (B) that has received the notification of the sleep mode sets the alarm mask of the receiver so as not to send an alarm even if the data signal is interrupted. Thereafter, the clock extraction unit 9 of the receiver and the data processing unit 4 of the receiver are turned off. Furthermore, the received optical power of the receiver is monitored.
S4. The transceiver (B) turns off the power of the modulator driver 3 and the data processing unit 4 of the transmitter. Thereby, it will be in a continuous light transmission state.
S5. The transceiver (B) returns a notification of setting completion.
S6. The transmitter / receiver (A) turns off the modulator driver 3 and the data processing unit 4 of the transmitter after confirming the setting completion notification from the opposite device. Thereby, it will be in a continuous light transmission state.

Next, when releasing the interface from the sleep mode, the operation is as follows.
S7. The transmitter / receiver (A) turns on the modulator driver 3 and the data processing unit 4 of the transmitter when canceling the sleep mode.
S8. The transceiver (A) notifies the opposite device of the recovery of the sleep mode.
S9. After receiving the notification of S8, the receiver of the transceiver (B) turns on the clock extraction unit 9 and the data processing unit 4 of the receiver.
S10. The receiver of the transceiver (B) cancels the alarm mask setting after confirming reception of the data signal.
S11. The transmitter of the transceiver (B) turns on the modulator driver 3 and the data processing unit 4 of the transmitter.
S12. The transceiver (B) notifies the opposite device of the completion of setting.
S13. After receiving the notification of S12, the transceiver (A) turns on the clock extraction unit 9 and the data processing unit 4 of the receiver.
S14. The transceiver (A) cancels the alarm mask setting after confirming the reception of the data signal.

  In the above procedure, the operation when a failure occurs is as follows. When the transmitter / receiver (A) cannot confirm the notification of the completion of setting in S5 or the notification of completion of the setting in S12, it is determined as a failure and the setting of each device is returned to the state before the setting. In the case of S5, the transceiver (A) cancels the alarm mask of the receiver, and turns on the clock extraction unit 9 and the data processing unit 4 of the receiver. In the case of S12, the transceiver (A) turns off the power of the modulator driver 3 and the data processing unit 4 of the transmitter.

  When S6 or S7 cannot be set, the transceiver (A) notifies the transceiver (B) to that effect.

  Also, in the optical power monitoring at the receiver, an alarm is given as a link failure when the measured value falls below a set threshold value.

  In the above procedure, the sleep mode is canceled from the transceiver (A) in which the sleep mode is set. However, it is also possible to cancel the sleep mode from the transceiver (B). The process of S7 is performed from the transceiver (B).

  Moreover, all the embodiments described above are illustrative of the present invention and are not intended to limit the present invention, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Light source 2 Data modulator 3 Modulator driver 4 Data processing part 5 Bias power supply 6 Client side transponder 7 Phase modulator 8 Opto-electric conversion part 9 Clock extraction part

Claims (5)

In an optical transceiver having a transmitter and a receiver,
Output means for converting the output light of the transmitter into continuous light that is not modulated;
Setting means for setting an alarm mask of the receiver;
Monitoring means for monitoring the optical power of the input light of the receiver;
An optical transmission / reception apparatus comprising: The output means is means for turning off the power of the modulator driver and the data processing unit of the transmitter,
The monitoring unit is a unit that turns off the clock extraction unit and the data processing unit of the receiver and determines occurrence of a link failure based on the optical power of the continuous light.
The optical transmission / reception apparatus according to claim 1, wherein the optical transmission / reception apparatus is provided. The output means is executed when no traffic flows to the transmitter;
The optical transmission / reception apparatus according to claim 1, wherein the setting unit and the monitoring unit are executed when a transmitter of a counter device executes the output unit. A method for reducing the power consumption of an optical transceiver having a transmitter and a receiver,
An output step of making the output light of the transmitter a continuous light that is not modulated;
A setting step for setting an alarm mask of the receiver;
A monitoring step of monitoring the optical power of the input light of the receiver;
A power saving method characterized by comprising: In an optical transmission system comprising an optical transmission / reception device having a transmitter and a receiver, and an optical transmission line connecting the devices,
Means for the transmitter to notify the receiver of the opposite device of the sleep mode;
Output means for converting the output light of the transmitter into continuous light that is not modulated;
Setting means for setting an alarm mask of the receiver of the opposite device;
Monitoring means for monitoring the optical power of the input light of the receiver of the opposite device;
Means for the receiver of the opposing device to notify the transmitter of setting completion;
A sleep mode setting means comprising:
Output means for converting the output light of the transmitter into modulated light that has been modulated;
Means for the transmitter to notify the receiver of the opposite device of sleep mode recovery;
Setting means for releasing the alarm mask of the receiver of the opposite device;
Termination means for terminating the monitoring of the optical power of the input light of the receiver of the opposite device;
Means for the receiver of the opposing device to notify the transmitter of setting completion;
A sleep mode recovery means comprising:
An optical transmission system comprising:

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