JP5494997B2 - Home-side apparatus, communication system, and power supply method - Google Patents

Description

  The present invention relates to a home-side device, an optical transceiver, a communication system, and a power supply method, and more particularly, to a home-side device, an optical transceiver, a communication system, and a power supply method for reducing power consumption.

  In recent years, the Internet has become widespread, and users can access various information on sites operated in various parts of the world and obtain the information. Along with this, devices capable of broadband access such as ADSL (Asymmetric Digital Subscriber Line) and FTTH (Fiber To The Home) are rapidly spreading.

  In IEEE Std 802.3ah (registered trademark) -2004 (non-patent document 1), a plurality of home side devices (ONU: Optical Network Unit) share an optical communication line, and a station side device (OLT: Optical Line Terminal). One method of a passive optical network (PON), which is a medium-sharing communication that performs data transmission with the network, is disclosed. That is, EPON (Ethernet (registered trademark) PON) in which all information is communicated in the form of an Ethernet (registered trademark) frame, including user information passing through the PON and control information for managing and operating the PON, and EPON An access control protocol (MPCP (Multi-Point Control Protocol)) and an OAM (Operations Administration and Maintenance) protocol are defined. By exchanging MPCP frames between the station side device and the home side device, the home side device joins and leaves, and uplink access multiplexing control is performed. Non-Patent Document 1 describes a registration method for a new home device, a report indicating a bandwidth allocation request, and a gate indicating a transmission instruction using an MPCP message.

  In addition, IEEE 802.3av (registered trademark) -2009 is standardized as the next generation technology of GE-PON (Giga Bit Ethernet (registered trademark) Passive Optical Network), which is an EPON realizing a communication speed of 1 gigabit / second. Even in the 10 G-EPON, that is, the EPON corresponding to a communication speed of 10 gigabits / second, the access control protocol is premised on MPCP.

  By the way, in order to save power in the PON system, various methods for causing the ONU to perform power saving operation during a period when it is not necessary to perform communication with the station side device have been studied.

  As an example of a method for achieving power saving in the PON system, for example, Japanese Patent Laying-Open No. 2010-213259 (Patent Document 1) discloses the following configuration. That is, in order to start power saving by a user apparatus and a network apparatus, power saving on a link, for example, an optical network is executed using information from the user apparatus and the network apparatus. Either the user device or the network device starts a sleep mode for the user device. By executing the sleep mode in the user device, the transmitter and the receiver of the user device can be turned off for a predetermined time (sleep time). During this sleep time, the transmitter and receiver do not consume power.

  Further, a laser driving circuit that is used in a transmitter for optical communication and saves power is disclosed in JP 2010-267924 A (Patent Document 2). That is, the laser drive circuit can obtain a modulation circuit for supplying a modulation current to the laser diode in accordance with the input burst data, a bias circuit for supplying a bias current to the laser diode, and a desired emission intensity and extinction ratio for the laser diode. And an APC circuit for controlling the modulation current and the bias current. When the transmission enable signal is on, burst driving is performed according to burst data input by the laser diode, and when the transmission enable signal is off, the laser diode is extinguished. The modulation circuit includes a modulation current cut-off circuit that cuts off the modulation current when the transmission enable signal is off, and the bias circuit includes a bias current cut-off circuit that cuts off the bias current when the transmission enable signal is off.

JP 2010-213259 A JP 2010-267924 A

  Generally, each electric circuit has a different rise time from the start of power supply to the electric circuit until the electric circuit starts operating. As in the laser driving circuit described in Patent Document 2, in a burst transmission unit for transmitting a burst signal, for example, data using AC coupling (capacitive coupling) in the first-stage gate circuit in the modulation circuit. Signal transmission takes place. For this reason, the rise time of the gate circuit becomes the longest due to the time constant of the AC coupling circuit.

  In the laser drive circuit described in Patent Document 2, current supply to each electric circuit is controlled by a common transmission enable signal. For this reason, for example, when the ONU includes this laser drive circuit, the rise time of the entire ONU is determined by the gate circuit having the slowest rise among the electric circuits in the laser drive circuit.

  That is, in the ONU, if the rise time of some of the electric circuits becomes long, the power saving operation cannot be performed depending on the length of the power saving period required from the station side device, or the normal state is changed from the power saving state. The return to the delay is delayed, and the throughput of the PON system is reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a home-side apparatus, an optical transceiver, a communication system, and a power supply method capable of saving power and improving throughput. Is to provide.

  In order to solve the above-described problem, a home-side apparatus according to an aspect of the present invention is a home-side apparatus for transmitting / receiving an optical signal to / from a station-side apparatus, and a plurality of units for transmitting or receiving the optical signal An electric circuit, a plurality of power supplies provided corresponding to the electric circuit, supplying electric power to the corresponding electric circuit, and controlling the start and stop of the electric power supply, and the home device saves power A power saving request receiving unit for receiving notification of a power saving period to be operated from the station side device, a response time of each electric circuit with respect to start and stop of power supply of the corresponding power source, and the power saving period And a power control unit for planning a power supply start and stop sequence for each of the power sources, and the power sources correspond to each other based on the sequence planned by the power control unit. Performing power supply to the electrical circuit.

  As a result, it is possible to select a circuit for stopping power supply and a circuit for continuing power supply according to the length of the power saving period required from the station side device. As a result, it is possible to achieve both power saving and improved throughput.

  The power supply control unit compares the response time of each electric circuit with the power saving period, and determines whether or not to stop power supply to each electric circuit during the power saving period based on a comparison result. To do.

  With such a configuration, it is possible to appropriately determine whether or not power supply to each electric circuit is stopped by simple processing.

  The home-side device further includes an optical transceiver that is detachable from the home-side device and includes at least any one of the electric circuits. The optical transceiver includes the at least one The response time of each electric circuit is stored, and the power control unit reads the response time stored in the optical transceiver.

  As described above, the response time of each electric circuit is stored in the optical transceiver that can be attached to and detached from the home-side device, and the response time of each electric circuit is different by the configuration in which the power supply control unit reads each response time. Even if replacement is performed, power saving operation can be performed appropriately.

  The power supply controller plans the sequence so that the electric circuits can operate before the timing at which the home device should resume transmission of the optical signal.

  With such a configuration, the timing of power saving processing of each home-side device in the communication system can be made common, so that control and management of each home-side device is facilitated in a host device, for example, a station-side device.

  The home device includes an electric circuit including a light emitting element and an electric circuit for supplying a modulation current to the light emitting element as the electric circuits.

  In this way, by making electric circuits with large power consumption and relatively large difference in response time the target of power saving processing, the effects of power saving and throughput improvement by appropriate power supply control are more prominent. Can be obtained.

  In order to solve the above-described problems, an optical transceiver according to an aspect of the present invention is an optical transceiver that can be attached to and detached from a home-side device for transmitting / receiving an optical signal to / from a station-side device, and transmits the optical signal. Or a plurality of electric circuits for receiving, a plurality of power supplies provided corresponding to the electric circuits, supplying power to the corresponding electric circuits, and capable of controlling the start and stop of power supply, A storage unit that stores a response time of each of the electric circuits with respect to start and stop of power supply of the corresponding power supply, and each response time is readable from the home side device, and each power source includes the home side Power is supplied to the corresponding electric circuit based on the start and stop sequence of the power supply of each power source planned by the apparatus.

  As described above, in the home side device, the configuration in which the rise time of each electric circuit written in the storage unit in the optical transceiver can be referred to from outside the optical transceiver, which part of the home side device is to be power-save. The autonomous power saving control to be selected can be performed.

  In order to solve the above-described problems, a communication system according to an aspect of the present invention is a communication system including one or more home-side devices and a station-side device for transmitting and receiving optical signals to and from each home-side device. Each of the home side devices is provided corresponding to the plurality of electric circuits for transmitting or receiving the optical signal, and supplies power to the corresponding electric circuit. A plurality of power sources capable of controlling start and stop, and the communication system includes a response time of each of the electric circuits with respect to start and stop of power supply of the corresponding power source, and power saving by the home-side device A power control unit for planning a start and stop sequence of power supply of each of the power sources based on a power saving period in which the operation is to be performed; each power source is planned by the power source control unit; Based on sequence for power supply to the corresponding of the electric circuit.

  As a result, it is possible to select a circuit for stopping power supply and a circuit for continuing power supply according to the length of the power saving period required from the station side device. As a result, it is possible to achieve both power saving and improved throughput.

  In order to solve the above-described problem, a power supply method according to an aspect of the present invention is provided with a plurality of electric circuits for transmitting or receiving optical signals with a station-side device, and corresponding to the electric circuits. A power supply method in a home device comprising a plurality of power supplies capable of supplying power to the electric circuit and controlling start and stop of power supply, wherein the home device performs a power saving operation Receiving the notification of the power saving period from the station side device, the response time of each electric circuit with respect to the start and stop of power supply of the corresponding power supply, and the power of each power supply based on the power saving period A step of planning a start and stop sequence of supply, and a step of supplying power from the power sources to the electric circuits based on the planned sequence.

  As a result, it is possible to select a circuit for stopping power supply and a circuit for continuing power supply according to the length of the power saving period required from the station side device. As a result, it is possible to achieve both power saving and improved throughput.

  According to the present invention, it is possible to save power and improve throughput.

It is a figure which shows the structure of the PON system which concerns on embodiment of this invention. It is a figure which shows the structure of the home side apparatus in the PON system which concerns on embodiment of this invention. It is a figure which shows the structure of the optical transceiver in the home side apparatus which concerns on embodiment of this invention. It is a figure which shows the data flow between the station-side apparatus and the home side apparatus in the PON system which concerns on embodiment of this invention, and the operation mode of a home side apparatus. It is the flowchart which defined the operation | movement procedure at the time of the house side apparatus in the PON system concerning embodiment of this invention performing a power saving process. It is a figure which shows the example of application of the power saving process by the home side apparatus which concerns on embodiment of this invention. It is a figure which shows the switching timing of each control signal in the optical output in the home side apparatus which concerns on embodiment of this invention, and a burst transmission part. It is a figure which shows the switching timing of each control signal in the optical output in the home side apparatus which concerns on embodiment of this invention, and a burst transmission part. It is the flowchart which defined the other example of the operation | movement procedure at the time of the house side apparatus in the PON system concerning embodiment of this invention performing a power saving process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a diagram showing a configuration of a PON system according to an embodiment of the present invention.

  Referring to FIG. 1, a PON system 301 is, for example, a 10G-EPON, and includes home-side devices 202A, 202B, 202C, and 202D, a station-side device 201, and splitters SP1 and SP2. Home-side devices 202A, 202B, 202C and station-side device 201 are connected via splitters SP1 and SP2 and optical fiber OPTF, and transmit / receive optical signals to / from each other. The home side apparatus 202D and the station side apparatus 201 are connected via the splitter SP2 and the optical fiber OPTF, and transmit / receive optical signals to / from each other.

  FIG. 2 is a diagram showing a configuration of a home device in the PON system according to the embodiment of the present invention.

  Referring to FIG. 2, home device 202 includes optical transceiver 21, PON reception processing unit 22, buffer memory 23, UN transmission processing unit 24, UNI (User Network Interface) port 25, and UN reception processing. Unit 26, buffer memory 27, PON transmission processing unit 28, and control unit (power saving request receiving unit and power supply control unit) 29.

  The optical transceiver 21 is detachable from the home device 202. The optical transceiver 21 receives the downstream optical signal transmitted from the station-side device 201, converts it into an electrical signal, and outputs it.

  The PON reception processing unit 22 reconstructs a frame from the electrical signal received from the optical transceiver 21 and distributes the frame to the control unit 29 or the UN transmission processing unit 24 according to the type of the frame. Specifically, the PON reception processing unit 22 outputs the data frame to the UN transmission processing unit 24 via the buffer memory 23 and outputs the control frame to the control unit 29.

  The control unit 29 generates a control frame including various control information and outputs the control frame to the UN transmission processing unit 24.

  The UN transmission processing unit 24 transmits the data frame received from the PON reception processing unit 22 and the control frame received from the control unit 29 to a user terminal such as a personal computer (not shown) via the UNI port 25.

  The UN reception processing unit 26 outputs the data frame received from the user terminal via the UNI port 25 to the PON transmission processing unit 28 via the buffer memory 27, and the control frame 29 receives the control frame received from the user terminal via the UNI port 25. Output to.

  The control unit 29 performs home-side processing related to control and management of the PON line between the station-side device 201 and the home-side device 202, such as MPCP and OAM. That is, various controls such as access control are performed by exchanging MPCP messages and OAM messages with the station-side apparatus 201 connected to the PON line. The control unit 29 generates a control frame including various control information and outputs it to the PON transmission processing unit 28. In addition, the control unit 29 performs various setting processes for each unit in the home device 202.

  The PON transmission processing unit 28 outputs the data frame received from the UN reception processing unit 26 and the control frame received from the control unit 29 to the optical transceiver 21.

  The optical transceiver 21 converts the data frame and control frame received from the PON transmission processing unit 28 into optical signals and transmits them to the station apparatus 201.

  FIG. 3 is a diagram showing the configuration of the optical transceiver in the home-side apparatus according to the embodiment of the present invention.

  Referring to FIG. 3, the optical transceiver 21 has a plurality of electric circuits for transmitting or receiving an optical signal.

  More specifically, the optical transceiver 21 includes a burst transmission unit 31, a burst reception unit 32, a master I / F (interface) 69, a CPU (Central Processing Unit) 70, a slave I / F 71, and a control register 72. Including. The burst transmission unit 31 includes a transmission modulation circuit 74 and a light emitting circuit 75 as an electric circuit for transmitting an optical signal. The burst transmission unit 31 includes power supplies 64 to 66, a timing circuit 67, and a bias circuit 68. The CPU 70 includes a storage unit 73 that is, for example, an EEPROM (Electrically Erasable Programmable Read Only Memory). Transmission modulation circuit 74 includes a pre-buffer circuit 61, an equalizer circuit 62, an output buffer circuit 63, and capacitors C1 and C2. Pre-buffer circuit 61 includes a resistor R. The light emitting circuit 75 includes a light emitting element LD and inductors L1 and L2.

  The burst receiving unit 32 is an electric circuit for receiving an optical signal, and includes a light receiving element PD, a TIA (transimpedance amplifier) 81, an LIA (limit amplifier) 82, a CDR (Clock and Data Recovery) 83, , Equalizer circuit 84, output buffer 85, and capacitors C3 to C6. The burst receiving unit 32 includes power supplies 86 to 90.

  In the burst transmission unit 31, the pre-buffer circuit 61 receives the transmission data which is the data frame from the UN reception processing unit 26 and the control frame from the control unit 29 via the capacitors C1 and C2, and amplifies the transmission data. Output. For example, the prebuffer circuit 61 receives the transmission data from the signal lines INP and INN as a balance signal.

  The equalizer circuit 62 performs waveform shaping of the transmission data received from the pre-buffer circuit 61, for example, corrects phase distortion and outputs the result.

  The output buffer circuit 63 supplies a modulation current to the light emitting circuit 75 based on the transmission data received from the equalizer circuit 62.

  The light emitting circuit 75 transmits the upstream optical signal to the station side device 201. In the light emitting circuit 75, the light emitting element LD is connected to a power supply node to which a power supply voltage Vdd1 is supplied via an inductor L1, and is connected to a bias circuit 68 via an inductor L2. The light emitting element LD emits light based on the bias current supplied from the bias circuit 68 and the modulation current supplied from the output buffer circuit 63, and changes the light emission intensity.

  The power supplies 64 to 66 can supply, for example, current as power to the pre-buffer circuit 61, the equalizer circuit 62, and the output buffer circuit 63, respectively, and control the start and stop of power supply. More specifically, the power supplies 64 to 66 each switch whether to supply current to the pre-buffer circuit 61, the equalizer circuit 62, and the output buffer circuit 63 based on the transmission disable signal received from the control unit 29.

  The bias circuit 68 supplies, for example, a bias current as power to the light emitting circuit 75. The bias circuit 68 switches whether to supply a bias current to the light emitting circuit 75 based on the transmission disable signal and the burst enable signal received from the control unit 29.

  Specifically, the power supplies 64 to 66 supply power to the pre-buffer circuit 61, the equalizer circuit 62, and the output buffer circuit 63, respectively, when the transmission disable signal is inactivated, and the transmission disable signal is When activated, the power supply is stopped.

  The bias circuit 68 supplies power to the light emitting circuit 75 when the transmission disable signal is deactivated and the burst enable signal is activated, and to the light emitting circuit 75 otherwise. Stop power supply.

  For example, the CPU 70 exchanges various data with the control unit 29 via an I2C bus including the signal line SCL and the signal line SDA.

  The master I / F 69 provides an interface function between the CPU 70 and the I2C bus.

  The slave I / F 71 provides an interface function between the CPU 70 and the control register 72.

  The CPU 70 writes various control data to the control register 72 via the slave I / F 71.

  In addition, the storage unit 73 in the CPU 70 stores response times of the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, and the light emitting circuit 75 with respect to the start and stop of power supply. For example, this response time is the rise time from when the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, and the light-emitting circuit 75 start operating after receiving power from the corresponding power supply or bias circuit, and This is the sum of the fall times from when the power supply is stopped until the operation is stopped.

  In the burst transmission unit 31, the response of the prebuffer circuit 61 is the slowest among the prebuffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, and the light emitting circuit 75, and the rise time of the prebuffer circuit 61 is for AC coupling. The time constant τ is determined by the capacitors C1 and C2 and the termination resistor R.

  The power supply 66 changes the amount of current supplied to the output buffer circuit 63 based on the control data APC1 written in the control register 72.

  The bias circuit 68 changes the amount of current supplied to the light emitting circuit 75 based on the control data APC2 written in the control register 72.

  Based on the burst enable signal received from the control unit 29, the timing circuit 67 preferentially stops the current supply of the power supply 66 over the current supply control of the power supply 66 by the transmission disable signal.

  In the burst receiving unit 32, the light receiving element PD converts the optical signal received from the station side device 201 into a current and outputs the current.

  The TIA 81 converts the current received from the light receiving element PD into a voltage and outputs the voltage to the LIA 82 via the capacitors C3 and C4.

  The LIA 82 binarizes the voltage level received from the TIA 81 and outputs it as received data.

  The CDR 83 reshapes the received data received from the LIA 82, extracts the timing from the received data, and performs the retiming of the received data based on the extracted timing, thereby establishing synchronization with the station side device 201. To do.

  The equalizer circuit 84 performs waveform shaping of received data received from the CDR 83, for example, corrects phase distortion and outputs the result.

  The output buffer 85 amplifies the reception data received from the equalizer circuit 84 and outputs the amplified data to the PON reception processing unit 22 via the capacitors C5 and C6. For example, the output buffer 85 outputs the received data from the signal lines OUTP and OUTN as a balance signal.

  The power supplies 86 to 90 supply, for example, current as electric power to the TIA 81, LIA 82, CDR 83, equalizer circuit 84, and output buffer 85, respectively. The power supplies 88 to 90 can control the start and stop of power supply. More specifically, the power supplies 88 to 90 switch whether to supply current to the CDR 83, the equalizer circuit 84, and the output buffer 85 based on the reception disable signal received from the control unit 29.

  Specifically, the power supplies 88 to 90 supply power to the CDR 83, the equalizer circuit 84, and the output buffer 85 when the reception disable signal is inactivated, and the reception disable signal is activated. If it is, the power supply is stopped.

  Hereinafter, each of the power supplies 64, 65, 66, the bias circuit 68, and the power supplies 88, 89, 90 may be simply referred to as “power supply”.

  The storage unit 73 in the CPU 70 stores response times of the CDR 83, the equalizer circuit 84, and the output buffer 85 with respect to the start and stop of power supply. For example, this response time is the rise time from when the CDR 83, the equalizer circuit 84, and the output buffer 85 start operating after receiving power supply from the corresponding power supply, and stops operating after the power supply is stopped. Is the sum of the fall times.

  In the burst receiving unit 32, the response of the CDR 83 is the slowest among the CDR 83, the equalizer circuit 84, and the output buffer 85, and the rising time of the CDR 83 becomes a lock time of a PLL (Phase Locked Loop) circuit in the CDR 83.

  Further, in the optical transceiver 21, power supply stop control from the power sources 86 and 87 to the TIA 81 and the LIA 82 is not performed in order to advance the lock time of the PLL circuit in the CDR 83. However, for example, when the CDR 83 is not provided in the optical transceiver 21, it is possible to control the start and stop of the power supply to the TIA 81 and the LIA 82 by outputting the reception disable signal to the power sources 86 and 87, respectively. .

[Operation]
Next, an operation when the PON system according to the embodiment of the present invention performs power saving control will be described with reference to the drawings. In the embodiment of the present invention, the power supply method according to the embodiment of the present invention is implemented by operating the home side apparatus 202. Therefore, the description of the power supply method according to the embodiment of the present invention is replaced with the following description of the operation of the home device 202. In the following description, FIGS. 1 to 3 are appropriately referred to.

  FIG. 4 is a diagram showing a data flow between the station side device and the home side device and an operation mode of the home side device in the PON system according to the embodiment of the present invention. In FIG. 4, processing between the station-side device and one home-side device will be described, but the same applies when a plurality of home-side devices are connected to the station-side device.

  Referring to FIG. 4, first, in a state where home-side apparatus 202 is operating in the normal mode, station-side apparatus 201 transmits a gate frame to home-side apparatus 202 (step S1), and power saving mode The setting frame is transmitted to the home apparatus 202. This power saving mode setting frame includes, for example, a power saving period TS and its start timing ta (step S2).

  Next, the home device 202 transitions to the power saving mode at the start timing ta of the power save period TS (step S3).

  Further, the home side device 202 transmits a power saving ACK frame corresponding to the power saving mode setting frame to the station side device 201 (step S4).

  The home device 202 continues to operate in the normal mode when it is determined that the transition to the power saving mode cannot be made from the relationship between the length of the power save period TS and the response time of each electric circuit in the optical transceiver 21 ( In step S3), a request error frame is transmitted to the station side device 201 (step S4).

  Next, the home device 202 transitions from the power saving mode to the normal mode at the end timing tb of the power saving period TS (step S5).

  Further, the station side device 201 transmits a gate frame to the home side device 202 regardless of whether the home side device 202 is operating in the normal mode or the power saving mode (step S6).

  Next, the power saving process in the home device 202 will be described in detail.

  The control unit 29 receives a notification of a power saving period (power save period) from which the home side device 202 should perform a power saving operation from the station side device 201.

  The control unit 29 starts the power supply of each power supply based on the response time of each electric circuit in the optical transceiver 21 with respect to the start and stop of the power supply of the corresponding power supply and the power saving period notified from the station side device 201. And plan outage sequences.

  For example, the control unit 29 compares the response time of each electric circuit with the power saving period, and determines whether or not to stop the power supply to each electric circuit during the power saving period based on the comparison result.

  Moreover, the control part 29 plans the sequence which can operate | move each electric circuit by the said timing on the basis of the timing which should return the transmission of an optical signal with the reference | standard at the time of completion | finish of the power saving period TS.

  That is, the timing at which power supply to each electrical circuit in the optical transceiver 21 is stopped is set to a timing at which each electrical circuit can resume operation before the end timing of the power save period TS. For this reason, when the power saving period TS is short, the power supply to the electric circuit having a long response time is not stopped.

  Each power source in the optical transceiver 21 supplies power to the corresponding electric circuit based on the sequence planned by the control unit 29.

  As an example of specific power saving processing, first, when the response time of each electric circuit in the optical transceiver 21 only needs to be within the power save period TS, that is, the response time of each electric circuit in the power save period TS is allowed to overlap. The case where it will be described.

  FIG. 5 is a flowchart defining an operation procedure when the home side apparatus in the PON system according to the embodiment of the present invention performs the power saving process.

  In FIG. 5, time T <b> 1 is the response time of the light emitting circuit 75. Time T2 is the response time of the transmission modulation circuit 74. This response time is the maximum response time among the response times of the pre-buffer circuit 61, the equalizer circuit 62, and the output buffer circuit 63. The time T3 is the maximum response time among the response times of the CDR 83, the equalizer circuit 84, and the output buffer 85.

  Here, for example, it is assumed that time T1 <time T2 <time T3. Further, the times T1 to T3 are stored in the storage unit 73 in the optical transceiver 21 as described above, and the control unit 29 can read the times T1 to T3 from the storage unit 73 via the I2C bus.

  Referring to FIG. 5, first, in the normal mode, control unit 29 receives a gate frame and a power saving mode setting frame from station-side apparatus 201. And the control part 29 acquires the power saving period TS contained in a power saving mode setting frame (step S11).

  Next, when the power saving period TS is equal to or longer than the time T3 (NO in step S12), the control unit 29 transmits a power saving ACK frame to the station-side apparatus 201 and shifts to the power saving mode. More specifically, the control unit 29 deactivates (turns off) the burst enable signal, activates (turns on) the transmission disable signal, and activates (turns on) the reception disable signal. That is, the control unit 29 performs control to stop power supply to the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, the light emitting circuit 75, the CDR 83, the equalizer circuit 84, and the output buffer 85 in the optical transceiver 21 ( Step S13).

  Then, according to the end timing of the power save period TS, the control unit 29 activates the burst enable signal, deactivates the transmission disable signal, and deactivates the reception disable signal (step S19).

  In addition, when the power saving period TS is less than the time T3 (YES in step S12) and is longer than the time T2 (NO in step S14), the control unit 29 transmits a power saving ACK frame to the station side device 201. Transmit and transition to power saving mode. More specifically, the control unit 29 deactivates the burst enable signal, activates the transmission disable signal, and deactivates the reception disable signal. That is, the control unit 29 performs control for stopping the power supply to the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, and the light emitting circuit 75 in the optical transceiver 21 (step S15).

  Then, the control unit 29 activates the burst enable signal and deactivates the transmission disable signal according to the end timing of the power save period TS (step S19).

  In addition, when the power saving period TS is less than the time T2 (YES in Step S14) and is longer than the time T1 (NO in Step S16), the control unit 29 transmits a request error frame to the station apparatus 201. The burst enable signal is deactivated, the transmission disable signal is deactivated, and the reception disable signal is deactivated. That is, the control unit 29 performs normal burst transmission control in which only the power supply to the light emitting circuit 75 is stopped in the optical transceiver 21 without transitioning to the power saving mode (step S17).

  Then, the control unit 29 activates the burst enable signal according to the end timing of the power save period TS (step S19).

  If the power saving period TS is less than the time T1 (YES in step S16), the control unit 29 transmits a request error frame to the station side device 201. That is, the control unit 29 does not transition to the power saving mode. Further, the control unit 29 cannot perform normal burst transmission control, and does not perform power supply stop control to the light emitting circuit 75 in the optical transceiver 21 (step S18).

  FIG. 6 is a diagram illustrating an application example of power saving processing by the home-side apparatus according to the embodiment of the present invention.

  Referring to FIG. 6, 500 μs from the transmission timing of report 1 to the transmission timing of report 2 in the upstream direction from home device 202 to station device 201 with respect to home device 202 from station device 201. Consider a case in which transmission of a plurality of burst data is requested during

  The interval TD1 between the report 1 and the data 1, the interval TD2 between the data 1 and the data 2, the interval TD3 between the data 2 and the data 3, and the interval TD4 between the data 3 and the report 2 are the power saving periods notified from the station side device 201, respectively. Corresponds to TS.

  For example, since the intervals TD1, TD3, and TD4 are longer than the response time T1 and shorter than the response time T2, the control unit 29 causes the optical transceiver 21 to stop only the power supply to the light emitting circuit 75. Transmission control is performed (step S17 in FIG. 5).

  In addition, since the interval TD2 is longer than the response time T2 and shorter than the response time T3, the control unit 29 moves to the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, and the light emitting circuit 75 in the optical transceiver 21. Control to stop the power supply is performed (step S15 in FIG. 5).

  Next, as another specific example of the power saving process, the burst enable signal and the transmission disable signal are set so that the response times of the transmission modulation circuit 74 and the light emitting circuit 75 in the optical transceiver 21 do not overlap in the power saving period TS. The case of switching between activation and deactivation of will be described.

  FIG. 7 is a diagram showing optical output in the home side apparatus according to the embodiment of the present invention and switching timing of each control signal in the burst transmission unit.

  Referring to FIG. 7, the burst enable signal is deactivated in accordance with the burst data transmission end timing (timing t1). Then, the bias current starts to decrease after the transmission delay time td of the burst enable signal elapses (timing t2), and the bias current becomes zero after the elapse of time Toff_ben (timing t3). Thereby, the current supply to the light emitting circuit 75 is stopped in the power saving period TS.

  Next, the transmission disable signal is activated after the time Ton_dis elapses from the timing t3 when the bias current becomes zero (timing t4). Thereby, the current supply to the transmission modulation circuit 74 is stopped in the power saving period TS.

  Next, after a time corresponding to the length of the power save period TS has elapsed from timing t4, the transmission disable signal is deactivated (timing t5). Then, after time Toff_dis elapses, the burst enable signal is activated (timing t6). The rise time of the transmission modulation circuit 74 is secured by this time Toff_dis.

  Then, the bias current starts to flow after elapse of the burst enable signal transmission delay time td from timing t6 (timing t7), and the bias current stabilizes slightly before timing t9 after elapse of (time Ton_ben1 + time Ton_ben2).

  Here, the length of (time Ton_ben1 + time Ton_ben2) is set so that the bias current is stabilized slightly before the timing t9 which is the end timing of the power saving period TS.

  The timing circuit 67 stops the current supply from the power supply 66 to the output buffer circuit 63 from the timing t5 to the timing t8, that is, the period from the timing t7 to the time when the time Ton_ben1 has elapsed. That is, the timing circuit 67 forcibly stops the supply of the modulation current from the output buffer circuit 63 to the light emitting circuit 75 until the level of the bias current is almost stabilized. As a result, it is possible to prevent the occurrence of overshoot or the like caused by the modulation current flowing in a state where the level of the bias current is unstable, so that the circuit operation can be stabilized.

  Then, invalid data starts to be transmitted at timing t8 when supply of the modulation current is started, and transmission of valid data is started at timing t9, which is the end timing of the power saving period TS.

  In FIG. 7, the time BENoff from timing t1 to timing t3 corresponds to the falling time of the light emitting circuit 75, the time BENon from timing t6 to timing t9 corresponds to the rising time of the light emitting circuit 75, and (time BENoff + time BEOn ) Corresponds to the response time T1 of the light emitting circuit 75.

  Further, the time Ton_dis from the timing t3 to the timing t4 corresponds to the falling time of the transmission modulation circuit 74, the time Toff_dis from the timing t5 to the timing t6 corresponds to the rising time of the transmission modulation circuit 74, and (time Ton_dis + time Toff_dis ) Corresponds to the response time T2 of the transmission modulation circuit 74.

  FIG. 7 shows a case where the power saving period TS is equal to or longer than (time T1 + time T2). In this case, as described above, the current supply to the light emitting circuit 75 and the current supply to the transmission modulation circuit 74 are stopped in the power save period TS.

  FIG. 8 is a diagram illustrating optical output in the home-side apparatus according to the embodiment of the present invention and switching timing of each control signal in the burst transmission unit.

  FIG. 8 shows a case where the power save period TS is less than (time T1 + time T2) and longer than time T1. In this case, since the response time T2 of the transmission modulation circuit 74 cannot be secured in the power save period TS, the current supply to the transmission modulation circuit 74 is not stopped.

  Referring to FIG. 8, the operation at timings t1 to t3 is the same as that in FIG.

  Next, after the time corresponding to the length of the power save period TS has elapsed from the timing t3 when the bias current becomes zero, the burst enable signal is activated (timing t6).

  Here, after the timing t3 when the bias current becomes zero, the transmission disable signal is not activated. Thereby, the current supply to the transmission modulation circuit 74 is continued in the power saving period TS.

  The operation at timings t7 to t9 is the same as that in FIG.

  FIG. 9 is a flowchart defining another example of an operation procedure when the home side apparatus in the PON system according to the embodiment of the present invention performs the power saving process. As in the case of FIG. 5, it is assumed that time T1 <time T2 <time T3.

  Referring to FIG. 9, first, in the normal mode, control unit 29 receives a gate frame and a power saving mode setting frame from station-side apparatus 201. And the control part 29 acquires the power saving period TS contained in a power saving mode setting frame (step S21).

  Next, when the power saving period TS is less than the time T1 (NO in step S22), the control unit 29 sends a request error frame to the station side device 201. That is, the control unit 29 does not transition to the power saving mode. Further, the control unit 29 cannot perform normal burst transmission control, and does not perform power supply stop control to the light emitting circuit 75 in the optical transceiver 21 (step S23).

  On the other hand, in the control unit 29, the power saving period TS is not less than time T1 (YES in step S22), (time T1 + time T2) is not more than time T3 (YES in step S24), and (time T1 + time T2) is If the power save period TS is less than the power save period TS (YES in step S25) and the power save period TS is greater than or equal to time T3 (YES in step S26), a power saving ACK frame is transmitted to the station side apparatus 201, and the power saving mode is set. Transition to. More specifically, the control unit 29 deactivates the burst enable signal, activates the transmission disable signal, and activates the reception disable signal. That is, the control unit 29 performs control to stop power supply to the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, the light emitting circuit 75, the CDR 83, the equalizer circuit 84, and the output buffer 85 in the optical transceiver 21 ( Step S27).

  Then, according to the end timing of the power save period TS, the control unit 29 activates the burst enable signal, deactivates the transmission disable signal, and deactivates the reception disable signal (step S33).

  Further, the control unit 29 determines that the power saving period TS is not less than the time T1 (YES in step S22), (time T1 + time T2) is not more than time T3 (YES in step S24), and (time T1 + time T2) is If the power save period TS is less than or equal to the power save period TS (YES in step S25) and the power save period TS is less than the time T3 (NO in step S26), a power saving ACK frame is transmitted to the station side apparatus 201, and the power saving mode is set. Transition to. More specifically, the control unit 29 deactivates the burst enable signal, activates the transmission disable signal, and deactivates the reception disable signal. That is, the control unit 29 performs control to stop power supply to the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, and the light emitting circuit 75 in the optical transceiver 21 (step S28).

  Then, the control unit 29 activates the burst enable signal and deactivates the transmission disable signal according to the end timing of the power save period TS (step S33).

  Further, the control unit 29 determines that the power saving period TS is not less than the time T1 (YES in step S22), (time T1 + time T2) is not more than time T3 (YES in step S24), and (time T1 + time T2) is If it is less than the power save period TS (NO in step S25), the request error frame is transmitted to the station side device 201, the burst enable signal is deactivated, the transmission disable signal is deactivated, and the reception disable signal is transmitted. Is deactivated. That is, the control unit 29 performs normal burst transmission control in which only the power supply to the light emitting circuit 75 is stopped in the optical transceiver 21 without transitioning to the power saving mode (step S30).

  Then, the control unit 29 activates the burst enable signal according to the end timing of the power save period TS (step S33).

  Further, the control unit 29 determines that the power save period TS is not less than the time T1 (YES in step S22), (time T1 + time T2) is greater than the time T3 (NO in step S24), and T3 is not more than the power save period TS. Yes (YES in step S29), and when (time T1 + time T2) is equal to or less than time TS (YES in step S31), a power saving ACK frame is transmitted to the station-side apparatus 201, and a transition is made to the power saving mode. More specifically, the control unit 29 deactivates the burst enable signal, activates the transmission disable signal, and activates the reception disable signal. That is, the control unit 29 performs control to stop power supply to the pre-buffer circuit 61, the equalizer circuit 62, the output buffer circuit 63, the light emitting circuit 75, the CDR 83, the equalizer circuit 84, and the output buffer 85 in the optical transceiver 21 ( Step S27).

  Then, according to the end timing of the power save period TS, the control unit 29 activates the burst enable signal, deactivates the transmission disable signal, and deactivates the reception disable signal (step S33).

  Further, the control unit 29 determines that the power save period TS is not less than the time T1 (YES in step S22), (time T1 + time T2) is greater than the time T3 (NO in step S24), and T3 is not more than the power save period TS. Yes (YES in step S29), and if (time T1 + time T2) is greater than time TS (NO in step S31), a power saving ACK frame is transmitted to the station-side apparatus 201, and the mode is changed to the power saving mode. More specifically, the control unit 29 deactivates the burst enable signal, deactivates the transmission disable signal, and activates the reception disable signal. That is, the control unit 29 performs control to stop the power supply to the light emitting circuit 75, the CDR 83, the equalizer circuit 84, and the output buffer 85 in the optical transceiver 21 (step S32).

  Then, the control unit 29 activates the burst enable signal and deactivates the reception disable signal in accordance with the end timing of the power save period TS (step S33).

  In addition, the control unit 29 determines that the power save period TS is equal to or longer than the time T1 (YES in step S22), (time T1 + time T2) is greater than time T3 (NO in step S24), and T3 is greater than the power save period TS. In such a case (NO in step S29), the request error frame is transmitted to the station apparatus 201, the burst enable signal is deactivated, the transmission disable signal is deactivated, and the reception disable signal is deactivated. That is, the control unit 29 performs normal burst transmission control in which only the power supply to the light emitting circuit 75 is stopped in the optical transceiver 21 without transitioning to the power saving mode (step S30).

  Then, the control unit 29 activates the burst enable signal according to the end timing of the power save period TS (step S33).

  By the way, in the home side device, if the rise time of some electric circuits becomes long, depending on the length of the power saving period required from the station side device, it becomes impossible to perform the power saving operation, or from the power saving state. The return to the normal state is delayed, and the throughput of the PON system is reduced.

  On the other hand, in the home side apparatus according to the embodiment of the present invention, control unit 29 receives notification of the power saving period in which home side apparatus 202 should perform the power saving operation from station side apparatus 201. The control unit 29 starts the power supply of each power supply based on the response time of each electric circuit in the optical transceiver 21 with respect to the start and stop of the power supply of the corresponding power supply and the power saving period notified from the station side device 201. And plan outage sequences. Each power source in the optical transceiver 21 supplies power to the corresponding electric circuit based on the sequence planned by the control unit 29.

  That is, the control for the bias circuit 68 that supplies the bias current to the light emitting circuit 75 and the control for the power sources 64 to 66 that supply the current to the transmission modulation circuit 74 can be executed separately.

  As a result, a circuit for stopping power supply and a circuit for continuing power supply can be selected according to the length of the power saving period requested from the station-side apparatus 201. Therefore, it is possible to achieve both power saving and throughput improvement.

  Moreover, in the home side apparatus which concerns on embodiment of this invention, the control part 29 compares the response time of each electric circuit in the optical transceiver 21, and a power saving period, and accompanies a power saving period based on a comparison result. Determine whether or not to stop power supply to each electric circuit.

  With such a configuration, it is possible to appropriately determine whether or not power supply to each electric circuit is stopped by simple processing.

  In the home side apparatus according to the embodiment of the present invention, the optical transceiver 21 has a plurality of electric circuits for transmitting or receiving optical signals, and is detachable from the home side apparatus 202. The optical transceiver 21 stores the response time of each electric circuit. And the control part 29 reads each response time which the optical transceiver 21 memorize | stores.

  As described above, the response time of each electric circuit is stored in the optical transceiver 21 that can be attached to and detached from the home-side device 202, and the response time of each electric circuit is different due to the configuration in which the control unit 29 reads out each response time. Even if the optical transceiver is replaced, the power saving operation can be appropriately performed.

  Moreover, in the home side apparatus which concerns on embodiment of this invention, the control part 29 plans the sequence which can operate each electric circuit by the timing which the home side apparatus 202 should restart transmission of an optical signal.

  With such a configuration, the power saving processing timing of each home-side device in the PON system can be made common, so that control and management of each home-side device in the host device, for example, the station-side device 201 is facilitated.

  Further, the home-side apparatus according to the embodiment of the present invention includes a light-emitting circuit 75 including a light-emitting element LD and a transmission modulation circuit 74 that supplies a modulation current to the light-emitting element LD as electric circuits to be subjected to power saving processing. With.

  In this way, by making electric circuits with large power consumption and relatively large difference in response time the target of power saving processing, the effects of power saving and throughput improvement by appropriate power supply control are more prominent. Can be obtained.

  For example, when an optical transceiver used in a home device is manufactured by a plurality of manufacturers, there is a possibility that the response time of each electric circuit in the optical transceiver differs depending on the manufacturer of the optical transceiver.

  Since power saving control and its efficiency depend on the response time of the home device, every time the optical transceiver in the home device is replaced, the power saving sequence may need to be changed in the host device such as the station device. There is.

  On the other hand, the optical transceiver 21 according to the embodiment of the present invention is provided with a plurality of electric circuits for transmitting or receiving optical signals and corresponding to the electric circuits, and supplies power to the corresponding electric circuits. A plurality of power supplies capable of supplying and controlling the start and stop of power supply, and the response time of each electric circuit with respect to the start and stop of power supply of the corresponding power supply, and each response time is stored in the home device 202 And a storage unit 73 that can be read from. Then, each power source in the optical transceiver 21 supplies power to the corresponding electric circuit based on the start and stop sequence of power supply of each power source planned by the home-side device 202.

  As described above, in the home side apparatus 202, the configuration in which the rise time of each electric circuit written in the storage unit 73 in the optical transceiver 21 can be referred to from the outside of the optical transceiver 21, which part in the home side apparatus 202 is determined. It becomes possible to perform autonomous power saving control for selecting whether to save power.

  In the PON system according to the embodiment of the present invention, the power saving mode setting frame transmitted from the station-side apparatus 201 includes the power save period TS and its start timing. However, the present invention is limited to this. is not. When the home side apparatus 202 can recognize the start timing of the power save period TS, such as when the start timing of the power save period TS corresponds to the end timing of the burst signal as in the example illustrated in FIGS. The power saving mode setting frame may not include the start timing of the power saving period TS.

  Further, in the PON system according to the embodiment of the present invention, in the example shown in FIGS. 6 to 8, the time interval between a certain burst signal and the next burst signal in the upstream direction is the home device 202 as the power save period TS. However, the present invention is not limited to this. For example, when the home device 202 can recognize the start timing of each burst signal and the length of the burst signal, the time when the power saving operation is actually performed in the home device 202, specifically, from the timing t4 in FIG. A configuration in which the period up to the timing t5 or the period from the timing t3 to the timing t6 in FIG.

  Moreover, in the home side apparatus which concerns on embodiment of this invention, although the electric circuit in the optical transceiver 21 was made into an object for power saving, it is not limited to this, The electric circuit outside the optical transceiver 21 is made into an object for power saving. The structure which makes it the power saving object may be sufficient as the electric circuit in the optical transceiver 21, and the electric circuit outside the optical transceiver 21 may be sufficient.

  Further, in the PON system according to the embodiment of the present invention, the station side device 201 notifies the home side device 201 of the power saving period TS, and the control unit 29 in the home side device 201 causes each of the electric circuits in the optical transceiver 21 to Although the configuration is such that the sequence of starting and stopping the power supply of each power source in the optical transceiver 21 is planned based on the response time and the power save period TS, the present invention is not limited to this. In a device (not shown) other than the home side device 202 and the station side device 201 in the PON system 301, at least one of the notification of the power save period and the plan of the power supply sequence may be executed.

  Further, in the PON system according to the embodiment of the present invention, the response time stored in the storage unit 73 is the operation after each electric circuit in the optical transceiver 21 receives power supply from the corresponding power supply or bias circuit. The sum of the rise time until the power supply and the fall time until the operation is stopped after the power supply is stopped is not limited to this. The response time stored in the storage unit 73 may be one of the rise time and the fall time.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

21 Optical Transceiver 22 PON Reception Processing Unit 23 Buffer Memory 24 UN Transmission Processing Unit 25 UNI Port 26 UN Reception Processing Unit 27 Buffer Memory 28 PON Transmission Processing Unit 29 Control Unit (Power Saving Request Reception Unit and Power Supply Control Unit)
31 burst transmission unit 32 burst reception unit 61 pre-buffer circuit 62 equalizer circuit 63 output buffer circuit 64 to 66, 86 to 90 power supply 67 timing circuit 68 bias circuit 69 master I / F
70 CPU
71 Slave I / F
72 Control Register 73 Storage Unit 74 Transmission Modulation Circuit 75 Light Emitting Circuit 81 TIA
82 LIA
83 CDR
84 Equalizer circuit 85 Output buffer 201 Station side device 202A, 202B, 202C, 202D Home side device 301 PON system C1-C6 Capacitor R Resistance LD Light emitting element PD Light receiving element L1, L2 Inductor INP, INN, SCL, SDA Signal line SP1, SP2 splitter OPTF optical fiber

Claims (5)

A home-side device for transmitting and receiving optical signals to and from the station-side device,
A plurality of electrical circuits for transmitting or receiving the optical signal;
A plurality of power supplies that are provided corresponding to the electrical circuits, supply power to the corresponding electrical circuits, and can control start and stop of power supply;
A power saving request receiving unit for receiving from the station side device a notification of a power saving period in which the home side device should perform a power saving operation;
A power control unit for planning a power supply start and stop sequence of each power source based on a response time of each electric circuit to start and stop of power supply of the corresponding power source and the power saving period; and With
Each power supply supplies power to the corresponding electric circuit based on the sequence planned by the power supply control unit,
The power supply control unit compares the response time of each electric circuit with the power saving period, and determines whether or not to stop power supply to each electric circuit during the power saving period based on a comparison result And
The power control unit performs a comparison with the power saving period in order from the largest response time, and when the power saving period is equal to or longer than the response time to be compared, a response time equal to or shorter than the response time to be compared is set. A home-side apparatus that selects the electric circuit that has the electric circuit as a power supply stop target.   2. The home-side apparatus according to claim 1, wherein the power supply control unit plans the sequence so that each of the electric circuits can operate before the timing at which the home-side apparatus should resume transmission of the optical signal.   The home device according to claim 1 or 2, wherein the home device includes an electric circuit including a light emitting element and an electric circuit for supplying a modulation current to the light emitting element as each of the electric circuits. . A communication system comprising one or more home-side devices and a station-side device for transmitting and receiving optical signals to and from each home-side device,
Each of the home side devices
A plurality of electrical circuits for transmitting or receiving the optical signal;
A plurality of power supplies that are provided corresponding to the electrical circuits, supply power to the corresponding electrical circuits, and can control the start and stop of power supply,
The communication system is:
Based on the response time of each electric circuit to the start and stop of the power supply of the corresponding power supply and the power saving period in which the home side device should perform the power saving operation, the start and stop of the power supply of each power supply It has a power control unit for planning the sequence,
Each power supply supplies power to the corresponding electric circuit based on the sequence planned by the power supply control unit,
The power supply control unit compares the response time of each electric circuit with the power saving period, and determines whether or not to stop power supply to each electric circuit during the power saving period based on a comparison result And
The power control unit performs a comparison with the power saving period in order from the largest response time, and when the power saving period is equal to or longer than the response time to be compared, a response time equal to or shorter than the response time to be compared is set. A communication system for selecting the electric circuit as a power supply stop target. A plurality of electrical circuits for transmitting or receiving optical signals to and from the station side device, and provided corresponding to the electrical circuits, supplying power to the corresponding electrical circuits, and controlling the start and stop of power supply A power supply method in a home device comprising a plurality of power sources capable of
Receiving from the station side device a notification of a power saving period in which the home side device should perform a power saving operation;
Planning the sequence of starting and stopping power supply of each power source based on the response time of each electrical circuit to the start and stop of power supply of the corresponding power source and the power saving period; and
Supplying power from each power source to each electric circuit based on the planned sequence,
In the step of planning the sequence, the response time of each electric circuit is compared with the power saving period, and the stop of power supply to each electric circuit during the power saving period based on the comparison result The presence / absence is determined and compared with the power saving period in order from the largest response time. When the power saving period is equal to or longer than the response time to be compared, the response time is equal to or shorter than the response time to be compared. A power supply method for selecting the electric circuit as a power supply stop target.

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