JP5903133B2 - Optical transmission / reception device control method, optical transmission / reception device, and optical communication system - Google Patents

Description

  The present invention relates to a control method for saving power in an optical transmission / reception device, an optical transmission / reception device, and an optical communication system including the same.

  As a typical network configuration of an optical access system, a single star configuration (Single star: SS) in which a subscriber side device (Optical network unit: ONU) and a station side device (Optical line terminal: OLT) are connected one-to-one. ) And a passive optical network (PON) configuration in which a plurality of ONUs are connected to one OLT.

  In the SS system, the ONU can occupy the OLT, so that high-speed communication is possible, but there is a disadvantage that the apparatus cost is high. On the other hand, in the PON system, the PON system is adopted in many optical access systems because a plurality of ONUs share one OLT and optical fiber equipment and are excellent in economic efficiency.

  PON downlink transmission is a continuous mode, and signals to each ONU are transmitted by time division multiplexing (TDM). The downstream signal is broadcast to all ONUs, and each ONU selectively receives only the signal addressed to itself. On the other hand, in uplink transmission, each ONU transmits a signal at a timing designated by the OLT in order to avoid a collision of signals by time division multiple access (TDMA). Since the transmission distance between the ONU and the OLT is different for each ONU, the upstream signal from each ONU has a feature that it is intermittent with different strength and phase, and the upstream signal is called a burst mode.

  Each of the ONU and the OLT has an optical transmission / reception device for transmitting / receiving an optical signal. In general, an optical transceiver includes an “optical receiver” that receives an input optical signal and an “optical transmitter” that outputs an optical signal. In general, an optical receiver includes a photodiode (PD), an equalizing amplifier (EQA), and a clock data regenerator (CDR). From the viewpoint of sharing of functions of a transmission apparatus, the optical receiver includes a CDR. May not be provided in the optical receiver, but may be provided in the logic circuit section in the subsequent stage of the optical receiver. The EQA includes an impedance conversion amplifier (TIA) and an amplitude limiting amplifier (LIA), and the CDR includes a clock recovery circuit (CRC) and an identification recovery circuit (Decision circuit).

  An input optical signal to the optical receiver is converted into a current signal by the PD and a voltage signal in the TIA. In the LIA, the amplitude is limited and amplified to a level that can be discriminated and reproduced by the subsequent CDR. In the CDR, the CRC extracts and reproduces the clock signal from the input signal, and the DEC discriminates and reproduces the input signal at the identification timing given by the reproduction clock, and is sent to the logic circuit section in the subsequent stage.

  The downstream signal is a continuous mode, and the optical signal intensity received by each ONU from the OLT is constant in principle, but is usually different for each user. For example, when a subscriber A and a subscriber B having different distances from the OLT are connected to the OLT in an arbitrary PON network, assuming that the optical signal strengths received from the OLT are P_down_A and P_down_B, respectively, P_down_A ≠ Although P_down_B, P_down_A and P_down_B do not change in principle. However, this may occur depending on changes in optical component performance over time. Since the ONU optical receiver may be provided to all subscribers whose transmission distance from the OLT, that is, transmission path loss, is greatly different, it is required to operate on optical signals having greatly different input light intensity. The

  Since the upstream optical signal is in burst mode, the TIA and LIA that constitute the OLT optical receiver amplify burst signals having significantly different intensities without distortion, and the CRC needs to extract a clock signal from burst signals having different phases. . In this case, each receiving circuit needs to be optimized for each burst signal, but each circuit requires a certain response time. From the viewpoint of providing an uplink communication service, it is necessary to support a large transmission line loss for wide-area accommodation, and therefore, an equalization amplifier is required to have a high sensitivity and a wide dynamic range reception performance.

  On the other hand, recent demands for power saving for communication devices are severe, and the same applies to optical access. In that case, it is effective to reduce the power consumption of the ONU, which is said to account for 60% of the power consumption in the optical communication network. A mechanism for achieving power saving by turning off the power of an optical transceiver constituting the ONU when there is no traffic to any ONU has been discussed (for example, see Non-Patent Document 1). What is discussed is “Dozing” that periodically shuts down only the optical transmitter, and “Cyclic sleep” that shuts down both the optical transmitter and the optical receiver.

“Study and Demonstration of Sleep and Adaptive Link Rate Control Mechanical for Energy Efficient 10G-EPON” IEEE / OSA Journal of Optical Opt. 2, no. 9, pp. 716-729, September 2010

  The problem in Dosing and Cyclic sleep in Non-Patent Document 1 is the response time required for the device to operate normally when the power is turned off and on. This is because the OLT-ONU communication cannot be performed during the response time of the element, so that the shared resource in the PON system cannot be effectively used, and the utilization efficiency is lowered. If the response time is too long, even the device cannot be shut down depending on the traffic interval input to the optical transceiver. That is, in realizing power saving in the PON, shortening the response time of components has been one of the major issues.

  In addition, the reception power of the optical receiver included in the ONU and the OLT changes according to the transmission distance between the OLT and the ONU. In an ONU having a short transmission distance from the OLT, it is possible to further reduce the power consumption of the optical transmitter by reducing the transmission optical power and reducing the LD drive current of the optical transmitter of the ONU. . This is because the optical receiver of the OLT has a wide input dynamic range in order to receive an optical signal from an ONU having a long transmission distance and a large transmission path loss without error.

  Accordingly, in order to solve the above-described problem, the present application relates to a method for controlling an optical transmission / reception device, an optical transmission / reception device, which can shorten a response time required for a normal operation of an element when a component power supply is turned off and on. The first object is to provide an optical communication system. In addition, a second object of the present application is to provide a method of controlling an optical transmission / reception device, an optical transmission / reception device, and an optical communication system that allow easy setting of light intensity according to a transmission distance.

  In order to achieve the first goal, the related invention relates to the reconfiguration of parts by storing the control voltage value used in the automatic gain control function of the equalizing amplifier of the optical receiver in a table having an information holding function. The control voltage resetting time at start-up was shortened.

Specifically, the control method of the optical transceiver according to the related invention includes: an optical transmitter that transmits an optical signal to an optical transmission line; and an optical signal from the optical transmission line is converted into an electric signal by a photodiode; An optical receiver comprising: an optical receiver that amplifies and receives an electrical signal output from the photodiode by an amplifier circuit;
The normal mode in which the optical signal can be transmitted and received and the power saving mode in which the optical signal cannot be transmitted and received are monitored, and the amplification condition of the optical receiver is stored in the optical receiver operating condition table in the normal mode, and the power saving is performed. When the mode is switched from the normal mode to the normal mode, activation control is performed to set the amplification condition stored in the optical receiver operation condition table in the optical receiver.

  An optical transmitter / receiver according to a related invention includes an optical transmitter that transmits an optical signal to an optical transmission line, and an optical signal from the optical transmission line is converted into an electric signal by a photodiode, and the photodiode outputs the electric signal. An optical receiver that amplifies and receives an electrical signal by an amplifier circuit, and a controller that performs the start-up control.

  The optical receiver has an equalizing amplifier, and stores control voltages of an automatic gain controller (AGC) and an automatic offset compensator (AOC) of the equalizing amplifier in a table. When returning from the power saving mode to the normal mode, the table values can be quickly reset in the equalization amplifier, so that the element start-up time can be shortened. Therefore, the power saving mode time of the optical receiver can be increased to save power. It becomes possible.

  Accordingly, the related invention is the first object, a method of controlling an optical transceiver capable of shortening the response time required until the element operates normally at the time of turning off and on the power supply of components, and the optical transceiver An apparatus can be provided.

  In the start-up control of the optical transceiver according to the related invention and the control method thereof, the amplification condition of the optical receiver after the response time of the amplifier circuit has elapsed from when the optical signal is input to the optical receiver is It is stored in an optical receiver operating condition table. Considering the time required for stabilization of the equalizing amplifier, accurate AGC and AOC control voltages can be stored in the table.

  In order to achieve the second goal, the present invention stores the operating conditions of the optical transmitter based on the power of the optical signal received by the optical receiver and the loss of the optical transmission path, so that the optical transmitter outputs We decided to optimize the power of the optical signal.

Specifically, the control method of the optical transceiver according to the present invention includes an optical transmitter that transmits an optical signal to an optical transmission line, an optical signal from the optical transmission line is converted into an electrical signal by a photodiode, An optical receiver comprising: an optical receiver that amplifies and receives an electrical signal output from a photodiode by an amplifier circuit;
The power of the optical signal input to the optical receiver, the transmission path loss of the optical transmission path, and the operating conditions of the optical transmitter with respect to the power and the transmission path loss are stored in advance in the optical transmitter operating condition table. Monitoring the power of the optical signal from the optical transmission line, and reading out the operating condition of the optical transmitter with respect to the power of the optical signal from the optical transmission line from the optical transmitter operating condition table and setting it in the optical transmitter Perform power saving control.

  An optical transmitter / receiver according to the present invention includes an optical transmitter that transmits an optical signal to an optical transmission line, an optical signal from the optical transmission line that is converted into an electric signal by a photodiode, and an electric signal that is output from the photodiode. An optical receiver that amplifies a signal by an amplifier circuit and receives the signal, and a controller that performs the power saving control.

  The optical transmitter has an automatic power controller. In addition, the optical receiver has a received signal strength indicator (RSSI). Furthermore, the optical transmission / reception apparatus also has a table for storing information on the LD driving conditions of the optical transmitter regarding the power of the received optical signal and the transmission path loss dependency. Information on transmission line loss can be easily obtained from RSSI. Thereby, since the LD transmission power (= drive current) of the ONU close to the OLT can be reduced, the power saving of the ONU can be achieved.

  Therefore, the present invention can provide a control method for an optical transmission / reception device and an optical transmission / reception device, which are the second object, and the light intensity can be easily set according to the transmission distance.

  The optical transmission / reception apparatus and the control method thereof according to the present invention can be controlled by combining the above-described start control and power saving control.

  In addition, if the optical communication system includes the optical transmission / reception apparatus and an optical transmission path that connects the optical transmission / reception apparatuses and enables bidirectional communication, a system capable of saving power can be obtained. .

The related invention provides an optical transmission / reception device control method, an optical transmission / reception device, and an optical communication system capable of shortening a response time required until a device operates normally when a component power supply is turned off and on. be able to.
In addition, the present invention can provide an optical transmission / reception device control method, an optical transmission / reception device, and an optical communication system, in which the setting of the light intensity according to the transmission distance is easy.

It is a figure explaining the structure of the optical transmitter-receiver which concerns on Embodiment 1. FIG. It is a figure explaining the structure of the optical transmitter-receiver which concerns on Embodiment 1. FIG. FIG. 6 is a diagram for explaining the operation of the optical receiver according to the first embodiment. It is a figure explaining the structure of the optical transmitter-receiver which concerns on Embodiment 2. FIG. FIG. 10 is a diagram for explaining the operation of the optical transmitter according to the second embodiment. It is a figure explaining the optical receiver input photocurrent of OLT using the optical transceiver which concerns on Embodiment 2. FIG.

  Embodiments of the present application will be described with reference to the accompanying drawings. The embodiments described below are examples of the present application, and the present application is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components. Moreover, when it demonstrates without attaching a branch number, it is description common to all the branch numbers of the said code | symbol.

(Embodiment 1)
In this embodiment, the response time required for the device to operate normally when the power of the component is turned off and on is applied to an optical transceiver that applies a power saving mechanism such as shutting down a component when traffic is low. Start control is shortened.

  FIG. 1 is a diagram illustrating an optical transmission / reception device 301 according to the first embodiment. The optical transmitter / receiver 301 converts the optical signal transmitted from the optical transmission line 100 to the optical transmission line 100 and the optical signal from the optical transmission line 100 by the photodiode 21, and outputs the electrical signal output from the photodiode 21. The optical receiver 20 which amplifies and receives by the amplifier circuit 22 and the controller 31 which performs starting control are provided.

  The start-up control performed by the controller 31 monitors the normal mode in which the optical signal can be transmitted / received for the optical receiver 20 and the power saving mode in which the optical signal cannot be transmitted / received, and the amplification condition of the optical receiver 20 is determined in the normal mode. The amplification condition stored in the optical receiver operating condition table 41 and stored in the optical receiver operating condition table 41 when switching from the power saving mode to the normal mode is set in the optical receiver 20. That is, the start control stores a control voltage value for operating the automatic gain control function of the amplifier circuit 22 included in the optical receiver, thereby shortening the control voltage resetting time when the component is restarted.

  As shown in FIG. 1, an ONU optical transceiver 301 includes an optical transmitter (Tx) 10, an optical receiver (Rx) 20, a WDM filter 50, an optical receiver operating condition table (Operation condition table). : Table_op) 41 and a controller (CTRL) 31. Tx10 transmits an upstream optical signal to the OLT, and Rx20 receives a downstream optical signal from the OLT.

  The Tx 10 includes a laser diode (LD) 11, an LD driver (LDD) 12, and an automatic power controller (APC) 13. The APC 13 has a function of controlling the output light intensity of the LD 11 to be constant. The LDD 12 has a function of driving the LD 11 in accordance with the uplink signal.

  The Rx 20 includes a photodiode (PD) 21 and an amplifier circuit 22. The amplifier circuit 22 is, for example, an equalizing amplifier (EQA). Hereinafter, the amplifier circuit 22 is referred to as EQA 22. The EQA 22 includes an impedance conversion amplifier (TIA) 23 and an amplitude limiting amplifier (LIM) 24.

  The optical receiver operation condition table 41 is a storage element such as a non-volatile memory, and is connected to the EQA 22 and stores information related to the operation conditions of the TIA and LIM constituting the EQA 22. Detailed operation of the optical receiver operating condition table 41 will be described separately.

  In FIG. 2, the block diagram of TIA23 and LIM24 of this embodiment is shown. The TIA 23 includes a TIA core 61, a gain controller (CTRL) 62, a single-balance converter (S / B) 63, and an automatic offset compensator (AOC) 64. The TIA core 61 has an automatic gain control (AGC) function, and realizes high sensitivity reception and wide input dynamic range by controlling the gain according to the strength of the current signal input to the TIA. Gain control is realized by changing a feedback resistance (Rf) 65 by a gain control unit 62. When the input optical signal intensity Pin to Rx20 is large, that is, when the input current amplitude Iin to the TIA 23 is large, the output voltage amplitude Vout_tia of the TIA core 61 becomes large, so that the gain control unit 62 makes the TIA core so that Vout_tia becomes small. 61 Rf65 is feedback controlled. When the input optical signal intensity Pin to the Rx 20 is small, that is, when the input current amplitude Iin to the TIA 23 is small, the output voltage amplitude Vout_tia of the TIA core 61 becomes small, so that the gain control unit 62 makes the TIA core so that Vout_tia becomes large. 61 Rf65 is feedback controlled.

  In order to improve the common-mode noise resistance, the signal interface is differentiated by the S / B 63. At this time, the DC offset voltage between the differential pairs is canceled by feedback control using the AOC 64. The LIM 24 has a squelch (SQH) 25 and has a function of detecting the presence or absence of an input signal to the LIM 24. In the configuration of FIG. 2, the SQH 25 detects whether an optical signal is input to the Rx 20 from the output of the LIM 24.

The gain control unit 62 and the AOC 64 are respectively connected to the optical receiver operation condition table 41, and V _CTRL which is an AGC control voltage and V _AOC which is an AOC control voltage are output to the optical receiver operation condition table 41, respectively. The SQH 25 is connected to the optical receiver operating condition table 41 after the time delay t _sqh via the delay line 26. The delay t _sqh considers the response time of AGC and AOC, and t _sqh > t _{response_AOC1} . Here, t _{response_AOC1} means the time required to stabilize the AOC of ONU1. That is, after the SQH 25 detects that an optical signal has entered Rx20, the delay line 26 provides a delay corresponding to the response time of the control system, and V _CTRL and V _AOC can be written to the optical receiver operating condition table 41. And

  Next, an operation when the optical transceiver 301 is applied to an arbitrary ONU constituting the PON system will be described. In this PON system, a power saving mechanism is implemented, and a “normal mode” in which the optical transceiver 301 is completely active and a part or all of the optical transceiver are shut down when there is little traffic in an arbitrary ONU. Power mode ". The return from the power saving mode to the normal mode may be triggered by the occurrence of input traffic to the ONU. If it is upstream, it is triggered by the input of upstream traffic from the user network interface (UNI) side. If it is downstream, downstream traffic from the service node interface (Service Node Interface: SNI) side that is higher than the OLT. The input may be used as a trigger. Further, the normal mode may be returned from the power saving mode according to an instruction / setting by the operator of the optical communication system.

FIG. 3 shows the temporal transition of the state at the node of each part constituting Rx20. First, RX20 at time t ₀ is the initial state is in the power saving mode, and in a state where the power supply voltage is not applied. It enters the normal mode at time _{t 1.} When the power supply voltage is applied to RX20, it becomes a time t ₂ reaches the power supply voltage Vcc necessary for operation. Thereafter, the gain of the TIA 23 converges to the optimum value Zt ₁ of the ONU ₁ at time t ₃ after the time t _{response_AGC 1} required for stabilization of AGC, and the AGC control voltage at that time is V _CTRL1 .

If AGC does not converge to a steady state, AOC will not converge. Taken from the time _{t 2} is the stabilization of AOC operation until time _{t 4} after time _{t Response_AOC1} lapse required for stabilization of the AOC, the AOC control voltage at that time is _{V AOC1.} However, t _{response_AGC1} <t _{response_AOC1} .

SQH25 outputs _{V Out_sqh} the output voltage amplitude of LIM24 exceeds the threshold _{V th.} The controller 31 reads V _{out_sqh,} and at t ₅ after the delay t _sqh , the optical receiver operating condition table 41 has a specific memory area inside, for example, if the value of field_sqh is “0”, “ 1 ″ is written, and the optical receiver operating condition table 41 holds the written information. On the other hand, if the value of field_sqh is already “1”, the controller 31 does nothing. The write certain memory areas _{V CTRL} and _{V AOC} also each _{V Out_sqh} having inside at the timing _{t 5,} for example field_AGC and field_AOC in the _{V CTRL1} and _{V AOC1} each respectively held.

Next, ONU _i enters the power saving mode again, the power is shut down at time t _6, the power supply voltage at time t ₇ is to converge to 0. Then reenters the normal mode at time _{t 8,} the power supply voltage reaches Vcc at time _{t 9.} At this time, since the optical receiver operation condition table 41 holds the optimal AGC control voltage V _CTRL1 and AOC control voltage V _AOC1 in the ONU _i , Rx20 can be instantaneously set to the optimal condition.

  In this embodiment, the S / B 63 is included in the TIA 23, but the LIM 24 may be included in the input stage thereof, or may be included in both the input stage and the output stage of the LIM 24. Although the ONU optical receiver constituting the optical access system has been described this time, this activation control is not limited to the ONU, but can be applied to an optical receiver that repeatedly turns the power on and off.

  In the optical transmission / reception apparatus 301 of this embodiment, when Tx10 and Rx20 transmit and receive optical signals having different wavelengths, each signal must be separated by the WDM filter 50 so as not to interfere with each other. It is not always necessary to have a WDM filter. For example, a WDM filter is not required in a bidirectional optical communication system using a directional multiplexing (Direction Duplex Multiplexing: DDM) system. In this embodiment, the application example to the ONU constituting the PON system has been described. However, the present invention is not limited to this, and it is also applicable to an optical transmission / reception apparatus constituting a point-to-point type optical communication network such as a single star. Is possible.

(Embodiment 2)
In this embodiment, power saving control is performed to reduce the bias and drive current of the optical transmitter by optimizing the output optical power of the optical transmitter.

  FIG. 4 is a diagram illustrating the optical transmission / reception device 302 according to the second embodiment. The optical transmission / reception device 302 converts Tx10 that transmits an optical signal to the optical transmission line 100, converts the optical signal from the optical transmission line 100 into an electrical signal by the photodiode 21, and amplifies the electrical signal output by the photodiode 21 by the EQA 22 Rx20 received and a controller 32 that performs power saving control.

  In the power saving control performed by the controller 32, the operating conditions of the optical transmitter with respect to the input optical power to the optical receiver and the transmission path loss are stored in the optical transmitter operating condition table 42 in advance, and the light from the optical transmission path 100 is stored. The power of the signal is monitored, and the operation condition of Tx10 with respect to the power of the optical signal from the optical transmission line 100 is read from the optical transmitter operation condition table 42 and set to Tx10. That is, the power saving control achieves power saving by referring to the optical transmitter operation condition table and outputting an optical signal having an appropriate power based on the optical signal received by the optical receiver.

  The operation when the power saving control of the present embodiment is applied to an arbitrary ONU optical transmission / reception apparatus constituting the PON system will be described. As shown in FIG. 4, the optical transceiver 302 includes Tx10, Rx20, a WDM filter 50, an optical transmitter operation condition table (Table_op) 42, and an LD drive condition controller (CONTROL: CTRL) 32. Each of Tx10 and Rx20 transmits an upstream optical signal to the OLT, and receives a downstream optical signal from the OLT. The Tx 10 includes a laser diode (LD) 11, an LD driver (LDD) 12, and an automatic power controller (APC) 13. The APC 13 has a function of controlling the output light intensity of the LD 11 to be constant. The LDD 12 has a function of driving the LD 11 in accordance with the uplink signal.

  The Rx 20 includes a photodiode (PD) 21, an equalizing amplifier (EQA) 22, and an input signal strength indicator (Received signal strength indicator: RSSI) 27. The RSSI 27 has a function of monitoring the intensity of photocurrent flowing through the PD 21.

  The optical transmitter operation condition table 42 is a storage element such as a non-volatile memory, for example, and stores information on the value of the photocurrent flowing through the PD 21 and the LD drive condition. The controller 32 is connected to the optical transmitter operating condition table 42, the APC 13, and the RSSI 27, and writes the photocurrent value of the PD 21 read from the RSSI 27 to the optical transmitter operating condition table 42. Also, the optical transmitter operating condition table The LD drive condition set in 42 is read, and the drive condition of the LD 11 is set for the APC 13.

Next, an operation when the optical transmission / reception apparatus 302 is applied to an arbitrary ONU constituting the PON system will be specifically described with reference to time charts shown in FIGS. Here, the operation of ONU ₁ and ONU _{2 having} different distances from the OLT will be described. Here, it is assumed that ONU ₁ has a longer transmission distance from OLT than ONU ₂ and has a larger transmission path loss.

It is assumed that time t ₀ is in an initial state, ONU ₁ and ONU ₂ are turned on at time t ₀ , and normal operation starts from time t ₁ . RSSI27 of ONU ₁ outputs the input light current value _{I IN_1} from time _{t 1} for the ONU _1, read out by the controller 32, and written to the optical transmitter operating condition table 42 by time _{t 2.} Controller 32 refers to the optical transmitter operating condition table 42, the optimum bias current _{I Bias_1} and the drive current _{i Drv_1} the LD 11, by time _{t 3} is set to LDD12 and APC13.

Operation of ONU ₂ also similar, RSSI27 having the ONU ₂ outputs the input light current value _{I IN_2} from time _{t 1} for the ONU _2, the controller 32 is read by an optical transmitter operating condition table by time _{t 2} 42 is written. Controller 32 refers to the optical transmitter operating condition table 42, the optimum bias current _{I Bias_2} and the drive current _{i Drv_2} the LD11 of ONU _2, by time _{t 3} is set to LDD12 and APC13.

It is assumed that ONU ₁ is permitted from the OLT to transmit an upstream signal from time t ₃ . Finished Tx10 the ONU ₁ is set up to time _{t 4,} and transmits the uplink data up to time _{t 5,} LD 11 of ONU ₁ until time _{t 6} ends the emission.

The operation of the ONU ₂ is almost the same. ONU ₂ is from the time _{t 7} is allowed to transmit an uplink signal from the OLT. Until time _{t 8} Tx10 of ONU ₁ has finished setup, and transmits the uplink data up to time _{t 9,} LD 11 of ONU ₁ until time _{t 10} ends the emission.

Next, the operation of the optical receiver included in the OLT optical transceiver when the technique of the present invention is applied to ONU ₁ and ONU ₂ will be described with reference to FIG. From the time _{t 12} upstream data ONU ₁ is inputted to the OLT optical receiver, after a certain response _time, between the _{t 13} to _{t 14,} receives a net data. From the time _{t 15} upstream data ONU ₂ is input to the OLT optical receiver, after a certain response _time, during the period from _{t 17} to _{t 18,} receives a net data. The input optical power in the OLT optical receiver, that is, the input photocurrent, is Ircv_1 for both the optical signal from the ONU 1 and the optical signal from the ONU 2, and the upstream optical signal from any ONU can be received without error.

  According to the present invention, it is possible to reduce the laser bias current and the drive current of the ONU having a short transmission distance from the OLT, so that not only the laser driver but also the entire optical access system can be saved.

  Although the WDM filter 50 is used in the optical transmission / reception apparatus 302, the WDM filter is not necessarily required depending on the optical communication system. For example, in the case of an optical communication system that applies a Direction Duplex Multiplexing (DDM) system. A WDM filter becomes unnecessary. Moreover, although the number of ONUs has been described as an example, three or more may be used.

(Other embodiments)
The activation control described in the first embodiment and the power saving control described in the second embodiment can be implemented in combination. That is, by connecting the RSSI 27, the controller 32, and the optical transmitter operation condition table 42 in FIG. 4 to the configuration of the optical transceiver 301 in FIG. 1, an optical transmission / reception device that can perform both startup control and power saving control is obtained. .

  By configuring an SS or PON optical communication network using such an optical transmission / reception apparatus, it is possible to save power in the entire optical communication system.

The following describes the components of the optical transceiver of FIGS.
(1)
An optical transmitter / receiver having an optical receiver and an optical transmitter, the optical receiver having a photodiode and an equalizing amplifier, the equalizing amplifier having an impedance conversion amplifier and an amplitude limiting amplifier,
A table for holding the automatic gain control voltage and the automatic offset compensation control voltage of the equalization amplifier not only when the power is turned on but also when the power is turned off;
A controller for writing an automatic gain control voltage value and an automatic offset compensation control voltage value of the equalization amplifier to the table and reading from the table;
The controller has a function of quickly reading out the two control voltage values from the table when the power is turned on again and resetting the equalizing amplifier.

(2)
An optical transceiver used in a point-to-multipoint optical communication network, wherein the optical transceiver includes an optical receiver and an optical transmitter, and the optical receiver includes a photodiode, an equalizing amplifier, and an input signal strength. The optical transmitter includes a laser diode, a laser diode driver, and an automatic power controller, the optical transmitter / receiver receives received optical power, a transmission line loss to which the optical receiver is connected, and those A table for holding the bias current and the drive current value of the laser diode driver according to
An optical transmission / reception apparatus comprising: a controller that reads out a bias current and a drive current value of the laser diode driver from the table based on operating conditions described in the table and sets the values for the automatic power controller.

(3)
The optical transceiver according to (2) above, wherein the optical receiver included in the optical transceiver includes a photodiode and an equalizing amplifier, and the equalizing amplifier includes an impedance conversion amplifier and an amplitude limiting amplifier.
A table for holding the automatic gain control voltage and the automatic offset compensation control voltage of the equalization amplifier not only when the power is turned on but also when the power is turned off;
A controller for writing an automatic gain control voltage value and an automatic offset compensation control voltage value of the equalization amplifier to the table and reading from the table;
The controller has a function of quickly reading out the two control voltage values from the table when the power is turned on again and resetting the equalizing amplifier.

(4)
A power saving method for an optical transmission / reception device, the optical transmission / reception device having an optical receiver and an optical transmitter, the optical receiver having a photodiode and an equalizing amplifier, and the equalizing amplifier converting impedance An amplifier, an amplitude limiting amplifier,
A table for holding the automatic gain control voltage and the automatic offset compensation control voltage of the equalization amplifier not only when the power is turned on but also when the power is turned off;
A controller for writing an automatic gain control voltage value and an automatic offset compensation control voltage value of the equalization amplifier to the table and reading from the table;
The controller reads the two control voltage values from the table promptly when power is turned on again and resets the equalization amplifier to save power in the optical transceiver. Method for saving power in the device.

(5)
A power saving method for an optical transceiver used in a point-to-multipoint optical communication network, the optical transceiver having an optical transmitter and an optical receiver, the optical receiver being a photodiode, etc. The optical transmitter includes a laser diode, a laser diode driver, and an automatic power controller, and the optical transmitter / receiver receives the received optical power, and the optical receiver is connected to the optical transmitter. A transmission line loss, and a table for holding the bias current and drive current value of the laser diode driver corresponding to them, a laser drive condition controller,
The laser driving condition controller reads out a bias current and a driving current value of the laser diode driver from the table based on the operating conditions described in the table, and sets the values for the automatic power controller, thereby transmitting and receiving the optical transceiver How to save power.

(6)
A method for saving power in the optical transmission / reception device according to (5), wherein the optical receiver included in the optical transmission / reception device includes a photodiode and an equalization amplifier, the equalization amplifier including an impedance conversion amplifier, an amplitude A limiting amplifier,
A table for holding the automatic gain control voltage and the automatic offset compensation control voltage of the equalization amplifier not only when the power is turned on but also when the power is turned off;
A controller for writing an automatic gain control voltage value and an automatic offset compensation control voltage value of the equalization amplifier to the table and reading from the table;
The controller reads out the two control voltage values from the table promptly when the power is turned on again and resets the equalization amplifier to save power in the optical transceiver.

(7)
An optical communication system that performs bidirectional communication using the optical transmission / reception device according to (1).
(8)
A star-type optical communication system, wherein bidirectional communication is performed using the optical transmission / reception device according to any one of (1) to (3) above.

10: Optical transmitter (Tx)
11: Laser diode (LD)
12: LD driver (LDD)
13: Automatic power controller (APC)
20: Optical receiver (Rx)
21: Photodiode (PD)
22: Amplifier circuit, equalizing amplifier (EQA)
23: Impedance conversion amplifier (TIA)
24: Amplitude limiting amplifier (LIM)
25: Squelch (SQH)
26: Delay line 27: Input signal strength indicator (RSSI)
31, 32: Controller 41: Optical receiver operating condition table 42: Optical transmitter operating condition table 50: WDM filter 61: TIA core 62: Gain controller 63: Single balance converter (S / B)
64: Automatic offset compensator (AOC)
65: Feedback resistance value (Rf)
100: Optical transmission path 301, 302: Optical transceiver

Claims (3)

An optical transmitter for transmitting an optical signal to the optical transmission line;
An optical receiver that converts an optical signal from the optical transmission path into an electrical signal with a photodiode, and amplifies and receives an electrical signal output from the photodiode with an amplifier circuit;
A method for controlling an optical transceiver comprising:
The operating conditions of the optical transmitter against the power and the power of the optical signal to be input to the optical receiver stored in advance in the optical transmitter operating condition table, may be held even when the power is turned off not only when the power is turned on, The power of the optical signal from the optical transmission line is monitored, and the operating condition of the optical transmitter with respect to the power of the optical signal from the optical transmission path is quickly read from the optical transmitter operating condition table when the power is turned on again. A method for controlling an optical transmitter / receiver that performs power saving control set in an optical transmitter. An optical transmitter for transmitting an optical signal to the optical transmission line;
An optical receiver that converts an optical signal from the optical transmission path into an electrical signal with a photodiode, and amplifies and receives an electrical signal output from the photodiode with an amplifier circuit;
A controller for performing power saving control according to claim 1;
An optical transceiver comprising: An optical transceiver according to claim 2;
An optical transmission line that connects the optical transceivers and enables bidirectional communication;
A point-to-multipoint optical communication system.

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