JP5811673B2 - COMMUNICATION DEVICE, COMMUNICATION SYSTEM, AND POWER CONTROL METHOD - Google Patents

Description

  The present invention relates to a communication device, a communication system, and a power control method for communicating data via a communication line, and more particularly, to a method for controlling power consumption of a subscriber device used in a PON (Passive Optical Network).

  Computer networks such as the Internet are spreading not only to companies and schools but also to general households. A user in a general household contracts with a computer network connection company called a provider and receives provision of network services. In other words, a user connects a subscriber device to a line that is branched from a main line of the network and extends to a home, and an information terminal using the network is connected to the subscriber device to use a computer network.

  In recent years, with the increase in the amount of communication information, a metal line is being replaced with an optical fiber having a large communication capacity as a communication line. As one of communication control technologies in a network using this optical fiber, there is FTTH (Fiber To The Home). PON (Passive Optical Network) is widely used as a service by this FTTH.

  A terminal device on the subscriber side installed in a home is called an ONU (Optical Network Unit). The plurality of ONUs are connected to an OLT (Optical Line Terminal), which is one station apparatus, via an optical splitter through an optical fiber. PON is a generic name for such a network configuration. In the PON, a plurality of ONUs share a transmission path between the optical splitter and the OLT. As a result, PON has an advantage over other network configurations in terms of economy, and is the basis for widespread use.

  More specifically, the ONU used in the PON converts a transmission frame generated by the MAC (Media Access Control) block that performs transmission frame generation, reception frame reception processing, and transmission timing control into an optical signal. An optical transmission interface (TxIF) block that transmits to the OLT, an optical reception interface (RxIF) block that converts an optical signal transmitted from the OLT into an electrical signal and supplies the electric signal to the MAC block, an IP (Internet Protocol) telephone, A plurality of user network interfaces (UNI) to which user terminals such as PCs (personal computers) are connected are included.

  In a PON having an optical power splitter at a branching portion of a transmission line, such as 10G-EPON (10 Gigabit Ethernet (registered trademark) PON), branching processing using time division multiplexing (TDM) by an optical splitter is performed. Is called. For this reason, transmission timing is controlled so that uplink signals from a plurality of ONUs do not collide. Specifically, a gate message is transmitted from the OLT to each ONU, and the transmission timing and transmission amount of the uplink signal are designated in each ONU. The transmission timing and the transmission amount are calculated in the MAC-LSI of the OLT based on the bandwidth allocation request amount included in the report signal from each ONU. Such ONU control is called dynamic bandwidth allocation (DBA). A broadcast method is used for the downlink signal. That is, the same downstream optical signal reaches all ONUs. Each ONU extracts only the information addressed to itself from the downlink signal arrived from the OLT, and performs reception processing of the received frame based on the information.

  In recent years, global warming has been taken up as an important issue on a daily basis, and the need to reduce greenhouse gas emissions is increasing. In addition, the reduction of power consumption meets the socially critical demand for saving fuel resources.

  Reducing the amount of power used by the network is one of the important issues in this field.

  Non-Patent Document 1 proposes three types of ONU power reduction methods from the viewpoint of ONU transmission / reception operations.

  1. The Dosing mode method is a method in which an ONU transmission block is operated in a power saving state when there is no upstream signal frame from the ONU to the OLT.

  2. In the Sleeping mode method, when there is neither an upstream signal nor a downstream signal between the ONU and the OLT, the transmission block and the reception block of the ONU are operated in a power saving state. This Sleeping mode is further divided into two types, Deep-Sleep and Cyclic-Sleep. The Deep-Sleep mode is a power reduction method that shuts down the power supply while leaving a minimum function. On the other hand, Cyclic-Sleep is a power reduction method that repeats a power saving state and a normal state at a predetermined cycle.

  3. In the Shedding mode method, UNIs that are not used among a plurality of UNIs, that is, UNIs that do not have a communication request are operated in a power saving state.

  In order to operate each block in the power saving state in the above three methods, generally, the power supply to each block is cut off or the voltage is lowered.

  Non-Patent Document 2 describes Energy-Efficient Ethernet (registered trademark), which is one of the power saving methods of the Ethernet interface. In the LPI (Low Power Idle) method in EEE, power consumption is reduced by stopping power supply to the MAC layer in a time zone not used for communication.

  Patent Document 1 describes a power saving method for controlling power supply to an internal buffer. That is, the optical subscriber line terminating device disclosed in Patent Document 1 has a frame buffer for storing a frame when a frame transmitted from the station side device is received in a situation where the supply of power to the internal circuit is stopped. A temporary buffer is provided for temporarily storing frames until it becomes available.

  Patent Document 2 describes a power saving method of an optical interface of an ONU in an IEEE 802 standard network. That is, the power supply to the receiver of the user device is also stopped based on the communication between the network device and the user device.

  Patent Document 3 describes a subscriber-side device that monitors a connection state with a station-side device and sets an ONU functional block to a low power consumption mode.

  In Patent Literature 4, a station-side device OLT having a buffer for storing user frames to be transmitted to the home-side device ONU has a time shorter than one round time from transmission to the home-side device ONU until transmission to the home-side device ONU again. The operation of transmitting a frame describing the power saving mode time is described.

  The above power saving methods are not only used alone, but a plurality of methods may be combined.

JP 2010-161566 A JP 2010-213259 A JP 2008-113193 A JP 2010-1114830 A

ITU-T Series G Supplement 45 “Transmission Systems and Media, Digital Systems and Networks”, GPON power conservation, May 2009 IEEE Std 802.3az-2010

  In the related art, ONU power saving technology is limited to the optical interface side and the UNI side, respectively. That is, the cooperation between the optical interface side and the UNI side has not been considered.

  In the related art, an operation of controlling the transition to the low power consumption state and suppressing the power consumption is described, but it is not described regarding the return from the low power consumption state to the normal communication operation state.

  FIG. 15 shows the operation of each part of the ONU in the ONU communication procedure according to the related technology.

  For example, when the Sheding operation is executed independently of the communication operation on the PON side, even if there is a communication request from the user terminal and a Gate signal is received from the OLT as shown in FIG. There is a delay in establishing communication between the user terminal and the user terminal. In related technology, this connection delay is an obstacle to ONU power saving, and ONU power saving technology including UNI has been required for efficient ONU power saving.

  That is, in a communication system in which a delay occurs in the connection, the communication speed of the entire system is suppressed, and the power consumed by each device during the delay is unnecessary.

  The present invention has been made in view of the above-described points. In a communication apparatus that communicates data via a communication line, the optical interface side and the UNI side are linked to reduce the delay in establishing communication between the OLT and the user terminal. It is an object of the present invention to provide a communication device, a communication system, and a power control method that control power consumption in consideration.

  It is another object of the present invention to provide an ONU having a power saving function based on a dynamic Shedding operation.

  In order to achieve the above object, a communication device of the present invention is a communication device installed between a network device and a terminal device, and communicates with a terminal connection means for communicating with the terminal device and the network device. Communication interface means to perform, access control means for controlling data relay between the communication interface means and the terminal connection means and communication with the network device and the terminal device, and a power supply for the terminal connection means connected to the access control means First power control means for controlling supply, the first power control means includes a plurality of states including an activation state capable of communicating with the terminal device and a low power drive state not communicating with the terminal device. The terminal connection means is set to one of the operation states, and the first power supply control means sets the terminal connection means in the low power drive state to the communication interface. And performing power control to shift to active state on the basis of the timing at which the scan means and the communication with the network device is performed.

  The communication system of the present invention is a communication system including a communication device installed between a network device and a terminal device, the communication device comprising: a terminal connection means for performing communication with the terminal device; and the network device. Communication interface means for performing communication, access control means for controlling data communication between the communication interface means and the terminal connection means and communication with the network device and the terminal device, and terminal connection means connected to the access control means First power control means for controlling power supply to the first power control means, wherein the first power control means includes an activation state capable of communicating with the terminal device and a low power drive state not communicating with the terminal device The terminal connection means is set to one of a plurality of operation states, and the first power supply control means passes through the terminal connection means in the low power drive state. Based on the timing at which the interface means communicates with the network device, the power supply control is performed so as to shift to the start state, and the access control means determines whether the terminal connection means is in the start state or the low power drive state. Provided with a notification means for notifying the network device, and when the network device transmits information addressed to the terminal connection means in the low power drive state among the terminal connection means, the power supply control so as to shift the terminal connection means to the activated state And the transmission of information is postponed until it is possible to transmit and receive information between the network device and the terminal device connected to the terminal connection means.

  Furthermore, the power control method of the present invention provides communication between a terminal connection unit that is installed between a network device and a terminal device, relays data to control communication, and communicates with the terminal device, and communication with the network device. A method for controlling power consumption of a communication device including an interface unit, wherein a plurality of operating states include a start state capable of communicating with a terminal device and a low power drive state not communicating with the terminal device Setting the terminal connection means to one of the operating states, and controlling the power supply so that the terminal connection means in the low power drive state shifts to the start state based on the timing at which communication between the communication interface means and the network device is performed. And performing.

  According to the present invention, it is possible to achieve power saving of the ONU by the Sheding operation.

Further, by matching the OLT and ONU communication timing with the UNI activation timing, communication from the OLT to the user terminal via the ONU is possible even when the ONU is in power saving operation. Further, the OLT or user terminal It is possible to detect one or both of the communication requests from and to take the UNI operation state according to the result.

  Further, not only UNI but also optical IF can be saved.

1 shows a configuration of a communication system and an ONU according to a first embodiment of the present invention. 1 shows a configuration of an LSI in an ONU according to a first embodiment of the present invention. 2 illustrates an example of a UNI power control operation according to the first embodiment of the present invention. FIG. 6 illustrates an ONU return operation from the OLT according to the first embodiment of the present invention. FIG. The operation of ONU return from the user terminal according to the first embodiment of the present invention will be described. The structure of the communication system and ONU by the 2nd Embodiment of this invention is shown. 4 shows a configuration of an LSI in an ONU according to a second embodiment of the present invention. 5 shows an example of power supply control operation of UNI and optical IF according to the second embodiment of the present invention. The operation of ONU return from the OLT according to the second embodiment of the present invention will be described. The operation of ONU return from the user terminal according to the second embodiment of the present invention will be described. An example of a UNI power control operation according to the third embodiment of the present invention will be described. 10 shows an example of power supply control operation of UNI and optical IF according to the third embodiment of the present invention. 6 illustrates operations of a UNI and an optical IF according to a third embodiment of the present invention. The structure of the communication system and ONU by the 5th Embodiment of this invention is shown. The connection delay by the operation | movement of the system in related technology is shown. An example of the correspondence between the Quiet operation time T_q defined by IEEE 802.3az and the Reference operation time T_r is shown. The content of UNI status notification to the OLT according to the fourth embodiment of the present invention is shown.

  An embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments shown below.

(First embodiment)
(Constitution)
An example of a network configuration and an example of an ONU configuration according to the first embodiment of the present invention are shown in FIGS.

  As shown in FIG. 1, an ONU 100 as a PON home-side device is connected to an OLT 200 as a station-side device via an optical fiber 300 and an optical splitter 500 in the network according to the present embodiment. A plurality of user terminals 400-1 to 400-3 are connected to the ONU 100. However, the number of user terminals is not limited to three.

  The ONU 100 according to the present embodiment includes an LSI 110, an optical interface (IF) 120, a coupler 130, a plurality of UNIs 140-1 to 140-3, and a UNI power supply control unit 150.

  As illustrated in FIG. 2, the LSI 110 includes a PON-PHY (Physical layer) 111, a PON-MAC 112, a UNI-MAC 113, a UNI-PHY 114, and a scheduling unit 115.

  The LSI 110 generates a transmission frame used for communication with the OLT 200 and processes the reception frame received from the OLT 200. Furthermore, the LSI 110 controls transmission timing in accordance with a control signal from the OLT 200, and also operates as data mediating means between the PON side network and the UNI side network. The LSI 100 also performs timing control of power control by the UNI power control unit 150 by the scheduling unit 115.

  The LSI 110 may be configured by a plurality of LSIs respectively corresponding to the functional blocks provided in the LSI 110, or all functions may be configured by one LSI.

  The optical IF 120 includes an optical transmitter (Tx) 121 and an optical receiver (Rx) 122. The optical transmitter (Tx) 121 converts the transmission frame generated by the LSI 110 into an optical signal and transmits it. The optical receiver (Rx) 122 converts the optical signal received from the OLT 200 into an electrical signal and supplies it to the LSI 110.

  The coupler 130 divides the path of the transmission signal and the reception signal.

  A plurality of user terminals 400-1 to 400-3 are connected to the plurality of UNIs 140-1 to 140-3, respectively, and perform communication between the user terminals 400-1 to 400-3 and the ONU 100.

  The UNI power control unit 150 controls the presence / absence of power supply to the plurality of UNIs 140-1 to 140-3 based on scheduling information from the LSI 110.

  Each of the UNIs 140 has two states, a start state in which communication with the user terminal 400 can be performed and a low power state in which communication is not performed under the control of the UNI power supply control unit 150.

  The UNI power supply control unit 150 acquires timing information determined between the ONU 100 and the OLT 200 via the LSI 110 and controls the power supplies of the UNIs 140-1 to 3 according to the timing information.

(Operation)
Next, the operation of the network and the ONU according to this embodiment will be described with reference to FIGS.

  When at least one of the plurality of user terminals 400-1 to 400-3 is communicating, the UNI and the optical IF 120 to which the communicating user terminal is connected do not enter a low power state. Therefore, only those in which the connected user terminal is not used among the plurality of UNIs 140-1 to 140-3 are set to the low power state.

  With this operation, the power saving of the ONU by the Sheding operation can be achieved.

  Normally, in the PON, in response to an uplink signal transmission timing instruction included in a Gate signal periodically transmitted from the OLT 200, an uplink signal including a declaration of a band requested by the ONU 100 and uplink traffic is transmitted.

  FIG. 3 shows the power control operation of the UNIs 140-1 to 3 in the ONU 100 according to this embodiment.

  As an initial state, there is no communication request from either the OLT 200 or the plurality of user terminals 400, and the plurality of UNIs 140-1 to 140-3 are in a low power state (step S101).

  The OLT 200 transmits a Gate signal for confirming whether there is a bandwidth request to the ONU 100, and the ONU 100 receives the Gate signal (step S102).

  The LSI 110 receives the Gate signal and issues an instruction to shift the UNIs 140-1 to 3 to the activated state via the UNI power control unit 150 (step S 103).

  The LSI 110 determines in which Gate terminal the OLT 200 requests communication with the plurality of user terminals 400 in the Gate signal from the OLT 200 (Step S104), and any of the UNIs 140-1 to 140-3 requests communication with the OLT 200. It is determined whether to do (step S105). If there is a communication request from either or both, the LSI 110 transmits a communication request signal to the OLT 200 and shifts to a normal PON operation (step S106).

  If there is no communication request from any of the OLT 200 and the plurality of user terminals 400-1 to 3 in the determinations of Step S104 and Step S105, a procedure for shifting to the low power state is performed with the OLT 200 (Step S107), and the UNI 140 is set to a low power state. The state is shifted (step S101).

  A communication request from either or both of the OLT 200 and the user terminal 400 is detected by the operation from step S104 to step S107, and the operation state of the UNI 140 shifts according to the detection result.

  At this time, some functions of the LSI 110 may be stopped.

  For signaling between the OLT 200 and the ONU 100 used in step S102 and step S107, IEEE P1904.1 (Service Interoperability in Ethernet Passive Optical Networks: SIEPON) Draft 1.0 or ITUAM TUES specified by ITU-T USE or ITU-T USE good.

  If the time from the report transmission to the OLT 200 in step S107 to the transition of the UNI 140 to the low power state in step S101 is set, the timing control of the operation from the OLT 200 to the UNI 140 via the ONU 100 is integrated into the OLT 200. Thereby, the timing control function of the ONU 200 is simplified. Further, when the communication timing between the OLT 200 and the ONU 100 and the startup timing of the UNI 140 are matched, communication from the OLT 200 to the user terminal 400 via the ONU 100 is possible even when the ONU 100 is in power saving operation.

  In the above operation, the UNI power control unit 150 obtains information on the presence / absence of a communication request, transmission / reception timing, and permission for transition to the low power state from the PON-MAC 112 and the UNI-MAC 113, and UNIs 140-1 to -3 in accordance with the information. Control the power supply.

  Next, an operation when a communication request is generated from the OLT 200 to the ONU 100 will be described with reference to FIG.

  The OLT 200 transmits a Gate signal including an activation instruction to the ONU 100 in a downstream signal in communication with the ONU 100 immediately after the communication request is generated.

  When the LSI 110 receives the Gate signal including the activation instruction, the LSI 110 issues an instruction to maintain the connection through the UNI power supply control unit 150 without shifting to the low power state after this point.

  The ONU 100 transmits a Report signal including a notification that the communication function is activated and the connection to the user terminal 400 is established to the OLT 200.

  When the OLT 200 confirms that the ONU 100 is in the activated state, the OLT 200 starts communication with the ONU 100 in the same manner as the normal PON operation, and the return of the ONU 100 is completed.

  Next, a case where a communication request from the user terminal side occurs will be described with reference to FIG.

  When the user terminal 400 makes a communication request, the user terminal 400 continues to send a signal including the communication request until the UNI 140 shifts to the activated state.

  When the UNI 140 is activated in response to the Gate signal from the OLT 200 immediately after the communication request is generated, the LSI 110 detects that there is a communication request from the user terminal 400.

  The LSI 110 transmits a report signal including a communication request with the OLT 200 to request bandwidth allocation, and at the same time, does not shift to the low power state via the UNI power supply control unit 150 and does not shift to the user terminals 400-1 to 400-3. Give instructions to stay connected.

  The OLT 200 allocates a band in accordance with a communication request from the ONU 100, and the return of the ONU 100 is completed.

  As described above, according to the first embodiment of the present invention, the UNI 140 is activated each time the ONU 100 communicates with the OLT 200, and the power saving method of the ONU in which the communication path from the OLT 200 to the user terminal 400 via the ONU 100 is established. Provided.

(Second Embodiment)
(Constitution)
A network configuration and ONU configuration according to the second embodiment of the present invention will be described with reference to FIG. 6 and FIG.

  The ONU 100 according to the present embodiment further includes an optical IF power supply control unit 160 in the ONU 100 according to the first embodiment. Since the other components are the same as those of the network configuration according to the first embodiment, the same reference numerals are assigned and description thereof is omitted.

  The optical IF power control unit 160 controls whether or not power is supplied to the optical IF 120 based on scheduling information from the LSI 110.

  The optical IF 120 takes two states, an activated state in which communication with the OLT 200 is possible and a low power state in which communication is not performed, under the control of the optical IF power supply control unit 160.

(Operation)
In the network according to the present embodiment, when there is no communication request between the OLT 200 and the ONU 100 for a certain period of time, that is, when there is no communication request from the OLT 200 and a plurality of user terminals for a certain period of time, the ONU 100 enters the sleep mode The power consumption of the ONU 100 is reduced. During the sleep mode, the optical IF 120 enters the low power state for a certain time (T_sleep) and then enters the start-up state again to check whether there is a communication request between the ONU 100 and the OLT 200. The optical IF 120 of the ONU 100 enters an activated state, and after transmitting and receiving a minimum signal (Gate, Report) to the OLT 200, if there is no communication request from both sides, it shifts to the low power state again for a predetermined time T_sleep. . Further, unused ones (no traffic) of the plurality of UNIs 140 are set to a low power state.

  Next, operations of the network and the ONU 100 according to the present embodiment will be described with reference to the drawings.

  FIG. 8 shows the power control operation of the UNIs 140-1 to 140-3 and the optical IF 120 in the ONU 100 according to this embodiment.

  In the initial state, there is no communication request from either the OLT 200 or the plurality of user terminals 400, and the plurality of UNIs 140-1 to 140-3 and the optical IF 120 are in a low power state (step S201).

  When the preset low power operation time T_sleep has elapsed (step S202), the LSI 110 activates the optical IF 120 and the plurality of UNIs 140-1 through 140 through the UNI power controller 150 and the optical IF power controller 160. An instruction to shift is issued (step S203).

  The OLT 200 transmits a Gate signal for confirming whether there is a bandwidth request to the ONU 100, and the ONU 100 receives the Gate signal (step S204).

  The LSI 110 determines in which Gate terminal the OLT 200 requests communication with the plurality of user terminals 400 in the Gate signal from the OLT 200 (Step S205), and any of the UNIs 140-1 to 140-3 requests communication with the OLT 200. It is determined whether or not to perform (step S206). If there is a communication request from either or both, the LSI 110 transmits a communication request signal to the OLT 200 and shifts to a normal PON operation (step S207).

  If there is no communication request from any of the OLT 200 and the plurality of user terminals 400-1 to 400 in the determinations in step S205 and step S205, the OLT 200 and a procedure for shifting to the low power state are performed (step S208), and the UNIs 140-1 to 140-3 are performed. Then, the optical IF 120 is shifted to the power saving state (step S201).

  At this time, some functions of the LSI 110 may be stopped.

  In the signaling message between the OLT 200 and the ONU 100 used in step S204 and step S208, IEEE P1904.1 (Service Interoperability in Ethernet Passive Optical Networks: SIEPON) is used even if it is specified in the Draft 1.0 or ITUAM TUUSE message specified in the Draft 1.0 or ITUAM. good.

  In the above operation, the UNI power control unit 150 and the optical IF power control unit 160 obtain from the PON-MAC 112 and the UNI-MAC 113 information on the presence / absence of a communication request, transmission / reception timing, and permission for transition to a low power state, and follow this information. Synchronously controls the power supply of the UNIs 140-1 to 140-3 and the optical IF 120.

  The time T_sleep during which the optical IF 120 is in the low power state may be a fixed value determined by the network in which the present invention is used, or a procedure for transition to the low power state with the OLT 200 each time the ONU 100 enters the low power state (step S208). It may be a variable value determined in

  When T_sleep is a fixed value, it is generally called a cyclic-sleep mode.

  Further, when the optical IF 120 is set in the low power state, both or only one of the optical transmitter Tx121 and the optical receiver Rx122 may be set in the low power state.

  According to this embodiment, in addition to the effects of the first embodiment, not only the UNI 140 but also the optical IF 120 can be saved, and the power consumption of the ONU 100 can be further reduced. Further, by setting T_sleep as a fixed value, it is possible to adapt to the cyclic-sleep mode discussed in ITU-T.

  Here, a case where a communication request is generated from the OLT 200 to the ONU 100 as in the case of an incoming IP phone call from another user will be described with reference to FIG.

  The OLT 200 transmits a Gate signal including an activation instruction to the ONU 100 in a downstream signal in communication with the ONU 100 immediately after the communication request is generated.

  When the LSI 110 receives the Gate signal including the activation instruction, the LSI 110 issues an instruction to maintain the connection without shifting to the low power state after this point via the optical IF power supply control unit 160 and the UNI power supply control unit 150.

  The ONU 100 transmits a Report signal including a notification that the communication function is in an activated state (Active) and the connection to the user terminal 400 is established to the OLT 200.

  When the OLT 200 confirms that the ONU 100 has been activated, the OLT 200 starts communication with the ONU 100 in the same manner as the normal PON operation, and the return of the ONU 100 is completed.

  Next, a case where a communication request from the user terminal side occurs will be described with reference to FIG.

  When the user terminal 400 makes a communication request, the user terminal 400 continues to send a signal including the communication request until the UNI 140 shifts to the activated state.

  When the optical IF 120 and the UNI 140 shift to the activated state in synchronization with the transmission timing of the Gate signal from the OLT 200 immediately after the communication request is generated, the LSI 110 detects that there is a communication request from the user terminal 400.

  The LSI 110 transmits a report signal including a communication request with the OLT 200, requests bandwidth allocation, and simultaneously connects via the optical IF power control unit 160 and the UNI power control unit 150 without shifting to the low power state. Give instructions to maintain.

  The OLT 200 allocates a band in accordance with a communication request from the ONU 100, and the return of the ONU 100 is completed.

  As described above, according to the second embodiment of the present invention, in addition to the effects of the first embodiment, it is possible to save the power of the optical IF and further reduce the power consumption of the entire ONU.

(Third embodiment)
In the first and second embodiments, the UNIs 140-1 to 3 are shifted to a low power state or an activated state at a timing determined by the ONU 100 and the OLT 200.

  When the OLT 200 transmits a downlink signal including data addressed to the user terminal 400 connected to the UNI 140 that is transitioning to the low power state while some or all of the UNIs 140-1 to 3 are in the low power state. The ONU 100 needs to buffer the frame. In that case, if it takes time to start up the UNIs 140-1 to 3, there arises a problem that the buffer is wasted or the frame of the downstream signal from the OLT 200 is discarded.

  Therefore, the present embodiment is characterized in that the communication timing between the ONU 100 and the OLT 200 is set in accordance with the timing at which the operation state of the UNIs 140-1 to 3 changes.

(Operation)
FIG. 11 shows the power control operations of the UNIs 140-1 to 140-3 and the optical IF 120 of the ONU 100 according to this embodiment.

  As an initial state, there is no communication request from either the OLT 200 or the plurality of user terminals 400, and all or some of the plurality of UNIs 140-1 to 140-3 are in a low power state (step S301).

  When the preset low power operation time T_shading has elapsed (step S302), the LSI 110 issues an instruction to shift the UNIs 140-1 to 140-3 to the activated state via the UNI power control unit 150 (step S303).

  The OLT 200 transmits a Gate signal for confirming whether there is a bandwidth request to the ONU 100, and the ONU 100 receives the Gate signal (step S304).

  The LSI 110 determines in which Gate terminal the OLT 200 requests communication with the plurality of user terminals 400 in the Gate signal from the OLT 200 (Step S305), and any of the UNIs 140-1 to 140-3 requests communication with the OLT 200. It is determined whether or not to perform (step S306). If there is a communication request from either or both, the LSI 110 transmits a communication request signal to the OLT 200 and shifts to a normal PON operation (step S307).

  If there is no communication request from either the OLT 200 or the plurality of user terminals 400-1 to 3 in the determinations in Step S305 and Step S306, the OLT 200 and a procedure for shifting to the low power state are performed (Step S308), and the UNI is set to the power saving state. Transition is performed (step S301).

  The ONU 100 notifies the OLT 200 of T_shading set between the ONU 100 and the plurality of user terminals 400 during the procedure for shifting to the low power state. The OLT 200 transmits a Gate signal after a time T_shading has elapsed since the UNIs 140-1 to 140-3 of the ONU 100 are in the power saving state.

  In the above operation, as shown in FIG. 12, the optical IF 120 may be set in the low power state only for a predetermined time T_shading after the procedure for shifting to the low power state with the OLT 200 (step S408).

  At that time, the value of T_shedding may be reported to the OLT 200 as T_sleep in the procedure for shifting to the low power state (step S408).

  Next, a method for determining T_shedding and T_sleep when the UNI 140 is an IEEE 802.3az-2010 Energy Effective Ethernet (EEE) standard interface will be described as a more specific example of the present embodiment.

  In EEE, a Low-Power Idle (LPI) mode is defined for power saving of the Ethernet port.

  In addition to the operations described in the first and second embodiments, the ONU 100 according to the present embodiment is an interface in which the UNIs 140-1 to -3 periodically repeat a low power state and a start-up state like an EEE standard interface. In this case, the time T_sleep when the optical IF 120 is in the low power state can be made to coincide with the period.

  As an example, the T_sleep determination method according to this embodiment will be described by taking the case where UNI is an EEE standard as an example.

  In the LPI mode, a Quiet operation (T_q) that does not transmit a signal and enters a low power state and a Refresh operation (T_r) that confirms connection are periodically performed. Each operation time is determined according to the interface standard as shown in FIG.

In the ONU 100 according to the present embodiment, the low power time T_sleep of the optical IF 120 is set as shown in FIG. 13 in order to synchronize the timings of the startup state and the low power state of the EIF standards UNI 140-1 to 140-3 and the optical IF 120.
T_sleep = T_shedding = T_q + (T_q + T_r) × N (Formula 1)
It is characterized by.

  However, N in (Formula 1) is a natural number.

  According to the present embodiment, even when the present invention is applied to an ONU having a UNI that periodically repeats a low power state and a start state, such as the IEEE 802.3az (EEE) standard UNI, the power consumption of the ONU is reduced. To do.

(Fourth embodiment)
The communication system according to the present embodiment is characterized in that the LSI 110 has a UNI monitoring function, adds a UNI state notification to the Report signal, and transmits it to the OLT 200.

  When a new user terminal 400 is connected to the UNI 140, the LSI 110 determines whether the user terminal shifts to the low power state and refers to the UNI number to determine the presence or absence of the low power state.

  When the ONU 100 receives a Gate signal transmitted from the OLT 200 and performs report transmission from the ONU 100 to the OLT 200, for example, as shown in FIG. 17, UNI operation state information associated with the UNI number is added and transmitted.

  When the OLT 200 sends a downlink signal to the ONU 100, if the downlink signal includes data addressed to the UNI in the low power state, the OLT 200 performs the procedures for returning the UNIs 140-1 to 140-3 and the optical IF 120 according to the procedure shown in the first or second embodiment. Data is transmitted after a communication path from the OLT 200 to the user terminal is secured. On the other hand, if the data addressed to the UNI whose downlink signal is active is included, the data transmission starts immediately without omitting the UNIs 140-1 to 140-3 and the optical IF 120 return procedure.

  As described above, according to the fourth embodiment of the present invention, an instruction to shift to an appropriate low power state according to the state of the user terminal 400 is performed, and the band between the ONU 100 and the OLT 200 based on the data addressed to the user terminal in the low power state or Buffer waste is reduced.

(Fifth embodiment)
The communication system according to the present embodiment is characterized in that the optical IF 120 includes a tunable optical transmitter Tx123 and a tunable optical receiver Rx124, as shown in FIG.

  With this configuration, the communication apparatus according to the present invention can be adapted to the wavelength division multiplexing technology.

  The present embodiment is an example in which the ONU according to the present invention is applied to a communication system in which the optical signal wavelength to be used changes according to the network conditions. Such a PON system is generally called a Wavelength Division Multiplex-PON (WDM-PON).

  In the WDM-PON, the OLT 200 includes a light source having a plurality of wavelengths and an optical receiver (Rx) having a plurality of wavelengths. WDM-PON is a communication system that can increase the bandwidth per ONU and the number of ONUs that can be accommodated by transmitting and receiving using wavelength division multiplexing technology.

  In addition, WDM-PON includes a method of assigning one wavelength to only one ONU and a method of assigning one wavelength to a plurality of ONUs by TDM technology.

  When the ONU according to the present invention is used in the latter type of WDM-PON, the operation shown in the first embodiment or the second embodiment can be applied.

  At that time, the wavelength setting after activation may be determined between the ONU 100 and the OLT 200 in the procedure for shifting to the low power state (steps S107 and S208).

  On the other hand, when the ONU according to the present invention is used for the WDM-PON of the former method, the ONU 100 is subjected to timing control from the OLT 200 because there is no collision of an upstream signal with another ONU connected to one OLT. The uplink signal can be transmitted without any problem.

  In that case, as shown in the third embodiment, the downlink signal transmission timing of the OLT 200 can be set in accordance with the Shedding operation.

  In addition to the above embodiments, the power saving of UNI and optical IF can be achieved in various types of next-generation optical access technologies by changing the transmission / reception system of optical IF.

  As mentioned above, although this invention was demonstrated with reference to five embodiment, this invention is not limited to said each embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. Further, the present invention includes a combination of some or all of the configurations of the above-described embodiments as appropriate. Moreover, although the number of user terminals and UNIs connected to the ONU 100 has been described as 3 for convenience, the scope of the present invention is not limited to this.

  Here, a part or all of the above embodiments can be described as in the following supplementary notes, but is not limited thereto.

  (Additional remark 1) It is a communication apparatus installed between a network apparatus and a terminal device, Comprising: The terminal connection means which communicates with the said terminal apparatus, The communication interface means which communicates with the said network apparatus, The said communication An access control means for controlling data communication between the interface means and the terminal connection means and communication with the network device and the terminal device, and a power supply to the terminal connection means connected to the access control means A plurality of first power control means for controlling, wherein the first power control means includes a start state capable of communicating with the terminal device and a low power drive state not communicating with the terminal device. The terminal connection means is set to one of the operation states of the terminal, and the first power supply control means is in the low power drive state. Communication apparatus and performs the power control to shift to active state on the basis of the timing at which the communication of the stage and said communication interface means and the network device is performed.

  (Supplementary Note 2) The access control means determines whether there is a communication request from at least one of the network device and the terminal device while the terminal connection means is in an activated state, and the first power control means When there is a communication request from at least one of the network device and the terminal device, power control is performed so as to maintain the activation state of the terminal connection unit, and when there is no communication request, the terminal connection unit is driven with low power The communication apparatus according to appendix 1, wherein power control is performed so as to shift to a state.

  (Additional remark 3) It is further provided with the 2nd power supply control means connected to the said access control means, and controls the power supply with respect to the said communication interface means, The said 2nd power supply control means can communicate with the said network apparatus The communication interface unit is set to one of a plurality of operation states including an activation state and a low power drive state in which communication with the network device is not performed, and the second power control unit is configured to Synchronizing with the operation of the power supply control means, the power supply control is performed so that the communication interface means in the low power drive state shifts to an activated state based on a timing at which communication between the communication interface means and the network device is performed. The communication apparatus according to Supplementary Note 1 or 2, wherein the communication apparatus is characterized.

  (Supplementary Note 4) The timing at which the first power control unit performs power control of the terminal connection unit and the timing at which the second power control unit performs power control of the communication interface unit are designated from the network device. The communication apparatus according to any one of supplementary notes 1 to 3, wherein the communication apparatus is determined based on scheduling information.

  (Additional remark 5) The communication timing of the said communication apparatus and the said network apparatus, and the timing which makes the said communication interface means a starting state or a low power drive state are determined based on the communication timing between the said terminal connection means and the said terminal device. The communication device according to any one of supplementary notes 1 to 4, wherein:

  (Supplementary note 6) The communication apparatus according to supplementary notes 1 to 5, wherein in at least one of the terminal connection unit and the communication interface unit, the startup state and the low power drive state are repeated at a predetermined cycle.

  (Supplementary note 7) A first time T1 during which the terminal connection means does not transmit a signal to the terminal device and a second time T2 during which the terminal connection means transmits a connection confirmation signal while the terminal connection means is in a low power drive state. 7. The communication apparatus according to any one of appendices 1 to 6, wherein: is repeated periodically.

(Supplementary note 8) The time T3 when the communication interface means is in the low power driving state is obtained from the first time T1, the second time T2, and an arbitrary natural number N,
T3 = T1 + (T1 + T2) × N
The communication apparatus according to appendix 7, wherein:

  (Supplementary note 9) The communication apparatus according to any one of supplementary notes 1 to 8, wherein the communication interface unit is a wavelength tunable transceiver capable of changing a wavelength of an optical signal used for transmission and reception.

  (Supplementary note 10) A communication system including the communication device according to supplementary notes 1 to 9, wherein the access control means determines whether the terminal connection means is in an activated state or a low power drive state. Power supply control so that when the network device transmits information addressed to the terminal connection means in the low power drive state of the terminal connection means, the terminal connection means is shifted to an activated state. And the transmission of the information is postponed until the transmission and reception of information between the network device and the terminal device connected to the terminal connection means becomes possible.

  (Supplementary note 11) The supplementary note 10, wherein the network device is a station building device, the network device and the communication device are connected by an optical transmission line, and the communication interface means is an optical transceiver. Communication system.

  (Supplementary Note 12) A terminal connection unit that is installed between a network device and a terminal device to control communication by relaying data and communicate with the terminal device, and a communication interface unit that communicates with the network device A method for controlling power consumption of a communication device including one of a plurality of operation states including an activation state in which communication with the terminal device can be performed and a low power drive state in which communication with the terminal device is not performed A step of setting the terminal connection means in one operation state, and a power supply for shifting the terminal connection means in the low power drive state to an activated state based on a timing at which communication between the communication interface means and the network device is performed And a step of performing control.

  (Additional remark 13) The step which determines the presence or absence of the communication request | requirement from at least one of the said network device and the said terminal device, while the said terminal connection means is an active state, From the said network device and the said terminal device from When there is a communication request, power control is performed to maintain the startup state of the terminal connection means, and when there is no communication request, power control is performed to shift the terminal connection means to a low power drive state. The power control method according to appendix 12, further comprising:

  (Supplementary Note 14) The communication interface unit is set to one of a plurality of operation states including a start state capable of communicating with the network device and a low power drive state not communicating with the network device. The communication interface means that is in a low power drive state in synchronization with the power control of the terminal connection means is shifted to an activated state based on the timing at which communication between the communication interface means and the network device is performed. The power control method according to appendix 12 or 13, further comprising the step of performing power supply control.

  (Supplementary note 15) The method further includes the step of determining the timing of performing power control of the terminal connection means and the timing of performing power control of the communication interface means based on scheduling information designated from the network device. The power control method according to appendices 12 to 14.

  (Supplementary note 16) The power control method according to any one of Supplementary notes 12 to 15, wherein in at least one of the terminal connection unit and the communication interface unit, the start state and the low power drive state are repeated at a predetermined cycle.

  (Supplementary Note 17) A first time T1 during which the terminal connection means transmits no signal to the terminal device and a second time T2 during which the terminal connection means transmits a connection confirmation signal while the terminal connection means is in a low power drive state. The power control method according to any one of appendices 12 to 16, further comprising a step of periodically repeating the steps.

(Supplementary Note 18) A time T3 when the communication interface means is in a low power drive state is obtained from the first time T1, the second time T2, and an arbitrary natural number N,
T3 = T1 + (T1 + T2) × N
The power control method according to appendix 17, wherein:

  (Supplementary note 19) The power control method according to supplementary notes 12 to 18, further comprising a step of changing a wavelength of an optical signal used for transmission and reception in the communication interface means.

  (Supplementary Note 20) Informing the network device whether the terminal connection means is in an activated state or a low power drive state; and the network device is in a low power drive state of the terminal connection means When transmitting information addressed to the terminal connection means, power control is performed so that the terminal connection means shifts to an activated state, and information can be transmitted and received between the network device and the terminal device connected to the terminal connection means. The power control method according to any one of appendices 12 to 19, further comprising the step of:

  (Supplementary note 21) The supplementary notes 12 to 20, wherein the network device is a station building device, the network device and the communication device are connected by an optical transmission line, and the communication interface means is an optical transceiver. Power control method.

  The present invention is not limited to the above-described embodiment, and can be suitably applied to power saving of an access network by a power saving compatible ONU.

100 ONU
110 LSI
111 PON-PHY
112 PON-MAC
113 UNI-MAC
114 UNI-PHY
115 Scheduling unit 120 Optical IF
121 Optical transmitter Tx
122 Optical receiver Rx
123 Tunable Optical Transmitter Tx
124 Tunable Optical Receiver Rx
130 coupler 140-1 UNI-1
140-2 UNI-2
140-3 UNI-3
150 UNI power supply control unit 160 Optical IF power supply control unit 200 OLT
300 Optical fiber 400 User terminal 500 Optical splitter

Claims (10)

A communication device installed between a network device and a terminal device,
Terminal connection means for communicating with the terminal device;
Communication interface means for communicating with the network device;
Relay of data between the communication interface means and the terminal connection means, and access control means for controlling communication with the network device and the terminal device;
A first power control means connected to the access control means for controlling power supply to the terminal connection means;
The first power supply control means is one of a plurality of operating states including an activated state capable of communicating with the terminal device and a low power drive state not communicating with the terminal device. To set the terminal connection means,
The first power control unit performs power control so that the terminal connection unit in a low power drive state shifts to an activated state based on a timing at which communication between the communication interface unit and the network device is performed. A communication device. The access control unit determines whether or not there is a communication request from at least one of the network device and the terminal device while the terminal connection unit is in an activated state,
When there is a communication request from at least one of the network device and the terminal device, the first power control unit performs power control so as to maintain an activated state of the terminal connection unit, and there is no communication request. 2. The communication apparatus according to claim 1, wherein power control is performed to shift the terminal connection unit to a low power driving state. A second power control means connected to the access control means for controlling power supply to the communication interface means;
The second power supply control means is one of a plurality of operating states including an activated state capable of communicating with the network device and a low power drive state not communicating with the network device. To set the communication interface means,
The second power supply control means is configured to synchronize the operation of the first power supply control means with the communication interface means in a low power drive state at a timing when communication between the communication interface means and the network device is performed. The communication apparatus according to claim 1, wherein the power supply control is performed so as to shift to an activated state based on the communication device. The timing at which the first power control unit performs power control of the terminal connection unit and the timing at which the second power control unit performs power control of the communication interface unit are respectively specified by the network device. The communication apparatus according to claim 3, wherein the communication apparatus is determined based on information.
In at least one of said terminal connection means and said communication interface means, and the activation state and a low power operating state, characterized by repeating a predetermined cycle, according to any one of claims 1 to 4 Communication device. While the terminal connection means is in the low power drive state, a first time T1 when the terminal connection means does not transmit a signal to the terminal device and a second time T2 when a connection confirmation signal is transmitted characterized in that it is repeated, the communication device according to any one of claims 1 to 5. The time T3 when the communication interface means is in the low power driving state is obtained from the first time T1, the second time T2, and an arbitrary natural number N,
T3 = T1 + (T1 + T2) × N
The communication apparatus according to claim 6, wherein: The communication apparatus according to any one of claims 1 to 7 , wherein the communication interface means is a wavelength tunable transceiver capable of changing a wavelength of an optical signal used for transmission and reception. A communication system including the communication device according to any one of claims 1 to 8,
The access control means includes a notification means for notifying the network device of whether the terminal connection means is in an activated state or a low power drive state.
When the network device transmits information addressed to the terminal connection means in the low power drive state among the terminal connection means, power control is performed so as to shift the terminal connection means to an activated state, and the network device And the terminal device connected to the terminal connection means, the transmission of the information is postponed until the transmission and reception of the information becomes possible. Communication including a terminal connection unit that is installed between a network device and a terminal device, controls data communication by relaying data, and communicates with the terminal device, and a communication interface unit that communicates with the network device A method for controlling the power consumption of an apparatus,
The terminal connection means is set to one of a plurality of operation states including a start state capable of communicating with the terminal device and a low power drive state not communicating with the terminal device. Steps,
And performing power control so that the terminal connection means in the low power drive state shifts to an activated state based on timing at which communication between the communication interface means and the network device is performed. , Power control method.

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