JP5084629B2 - Subscriber termination device and power supply control method - Google Patents

Description

  The present invention relates to an optical communication system, and more particularly to a subscriber termination device and a power supply control method for a PON (Passive Optical Network) system which is one of access optical communication systems.

  Conventionally, a point-to-multipoint access optical communication system called a PON system has been widely used as a system for realizing a public line network using optical fibers. The PON system is composed of one OLT (Optical Line Terminal) which is a station side device and ONU (Optical Network Unit) which is a plurality of subscriber terminal devices connected via an optical star coupler. In the PON system, the OLT and most of the optical fiber that is the transmission path can be shared with a plurality of ONUs, so that the operation cost can be reduced. In addition, since the optical star coupler which is a passive component does not require power supply, it is easy to install outdoors and has an advantage of high reliability. For these reasons, the PON system has been actively introduced in recent years as a trump card for realizing a broadband network.

  For example, in GE-PON (Gigabit Ethernet (registered trademark) -Passive Optical Network) standardized by IEEE (Institute of Electrical and Electronics Engineers, Inc.) 802.3ah and having a transmission rate of 1.25 Gbit / s, For downstream communication from the OLT to the ONU, a broadcast communication system using an optical wavelength band of 1.49 μm is employed. Each ONU extracts only the data addressed to its own station in the assigned time slot. On the other hand, the upstream communication from each ONU to the OLT employs a time division multiplexing communication system that uses the optical wavelength band of 1.31 μm and controls the transmission timing so that the data of each ONU does not collide.

  In the upstream communication of the PON system as described above, the optical transmission unit of each ONU generates an upstream optical data signal according to the transmission timing of transmission data, but does not generate an optical data signal. Even in the band, the optical transmission unit consumes the same power.

  In addition, when a communication device that employs a method other than the conventional optical communication is replaced with an optical communication device, the input / output unit includes an optical interface, so that power consumption is higher than that of the communication device before replacement. In order to suppress an increase in power consumption due to replacement, various methods for reducing the power of the entire communication apparatus have been proposed in recent years. For example, Patent Document 1 below proposes a technique for reducing power consumption by determining whether or not to transmit a packet to another station and stopping the power supply and optical output of the data processing unit based on the determination result. .

JP 2007-214731 A

  However, according to the technique described in Patent Document 1, power is always supplied to the optical transmission unit with the largest power consumption. Therefore, there is a problem that the effect of reducing power consumption is limited.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a subscriber termination device and a power supply control method that reduce the power consumption of the optical transmission unit and reduce the power consumption of the entire device. .

  In order to solve the above-described problems and achieve the object, the present invention provides a subscriber termination device comprising optical transmission means for converting transmission data generated as an electrical signal into an optical signal and transmitting the optical signal. The transmission timing information that is information for indicating the transmission timing of the packet included in the received packet is detected, the transmission time zone of the transmission data is determined based on the detected transmission timing information, and the determined transmission time Data processing means for outputting a band and transmission data to the optical transmission means, and determining a power supply time zone which is a time for supplying power to the optical transmission means based on the determined transmission time zone; Power supply means for supplying power to the optical transmission means based on a power supply time zone, wherein the optical transmission means transmits the optical signal based on the transmission time zone. To.

  According to the present invention, the transmission timing information of the uplink signal is detected from the transmitted transmission packet, the transmission timing of the packet is controlled based on the detected transmission timing information of the uplink signal, and the transmission time zone of the packet is determined. Since the power is supplied to the optical transmission unit during the determined transmission time zone and the power is not supplied to the optical transmission unit except during the transmission time, the power consumption of the optical transmission unit is reduced, and the power consumption of the entire device is also reduced. It is possible to reduce the effect.

  Embodiments of a subscriber termination device according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a functional configuration example of a first embodiment of a subscriber termination device according to the present invention. The subscriber termination device of this embodiment operates as an ONU of the PON system. As shown in FIG. 1, a subscriber termination device (hereinafter referred to as ONU) 1 according to the present embodiment receives a WDM (Wavelength Division Multiplexing) filter 2 that multiplexes and demultiplexes transmission / reception signals having different wavelengths, and an optical data signal. An optical receiver 3 that converts the data into an electrical data signal, an optical transmitter 4 that converts the electrical data signal into an optical data signal, and a PON that controls a PON system such as MAC (Media Access Control) and protocol management. -It is comprised with LSI (Large Scale Integration) 5 and the power supply part 6 which supplies a power supply to each functional block.

  Further, the PON-LSI 5 performs reception data processing on the received packet and outputs it to the UNI (User Network Interface), receives data transmitted from the UNI, performs predetermined transmission data processing, and outputs to the optical transmission unit 4 A unit 51 is provided. Furthermore, the data processing unit 51 includes an uplink transmission timing information detection unit 52 that detects uplink transmission timing information that is information for instructing the transmission timing of the uplink signal included in the received packet. In the present embodiment, when the OLT of the PON system to which the ONU 1 belongs transmits to each ONU, the packet is transmitted including the upstream transmission timing information for the destination ONU in the overhead area of the packet.

  FIG. 2 is a timing chart for explaining the packet sequence received by the ONU 1 and the power supply status to each functional block. The stage “(a) Received packet string” indicates a packet string received by the ONU 1, and the packet 100 addressed to the own station is indicated by a thick line, and the packet 200 addressed to another station is indicated by a thin line. Each packet is composed of an overhead area (OH) and a data area (DATA), and identification information indicating which ONU the packet is destined for is written in the overhead area.

  The stage of “(b) PON-LSI, optical receiver power supply” indicates the power supply status to the PON-LSI 5, optical receiver 3, and indicates that the hatched part is supplied with power. The stage of “(c) uplink transmission timing information detection” indicates the timing at which uplink transmission timing information is detected from the received packet. The stage of “(d) transmission packet sequence” indicates a packet sequence transmitted by the ONU 1. The stage “(e) Optical transmitter power supply” shows the power supply status to the optical transmitter / receiver 4.

  In the present embodiment, as shown in the “(e) optical transmitter power supply status” stage of FIG. 2, the optical transmitter is only present when there is a transmission packet shown in the “(d) transmission packet string” stage. When power is supplied to 4 (the power is turned on) and no packet is transmitted, no power is supplied to the optical transmitter 4.

  Next, the operation of this embodiment will be described with reference to FIGS. First, the data processing unit 51 shown in FIG. 1 detects the destination identification information written in the overhead area of each received packet, and receives only packets whose destination identification information indicates the own station (packets addressed to the own station). Perform data processing. As data processing, the data portion of the received packet is extracted, subjected to predetermined reception processing, and output to the UNI. The uplink transmission timing information detection unit 52 of the data processing unit 51 detects the uplink transmission timing information included in the packet, and determines the transmission timing of the packet transmitted by the own station based on the detected uplink transmission timing information. To do. The data processing unit 51 sends transmission data to the optical transmission unit 4 according to the transmission timing.

  Note that the OLT determines a transmission timing for transmitting an uplink signal to each ONU so that the data of each ONU does not collide, and information indicating the determined timing is transmitted as a transmission packet to the corresponding ONU. To be sent.

  Further, the uplink transmission timing information detection unit 52 determines the start time of the transmission data based on the determined transmission timing, determines the packet length of the data to be transmitted to the optical transmission unit 4, and determines the packet length The transmission end time is determined based on the start time. Then, for each packet to be transmitted, the optical transmission unit 4 is notified of the determined start time to end time (transmission time zone), and the transmission time zone is used as the power supply time to the optical transmission unit 4. 6 is instructed. The power supply unit 6 supplies power to the optical transmission unit 4 in the designated transmission time zone. Further, the power supply unit 6 does not supply power to the optical transmission unit 4 during times other than the instructed transmission time zone.

  That is, as shown in the example of FIG. 2, the uplink transmission timing information detection unit 52 extracts information written in the data area of the received packet addressed to the own station and sends it to the UNI, and transmits the transmission packet sequence. The power supply unit 6 is controlled such that the power supply of the optical transmission unit 4 is the same as the transmission time of the packet. By doing in this way, the power of the optical transmission part 4 other than the time of transmission of an uplink transmission packet can be cut.

  Thus, in this embodiment, the uplink transmission timing information detection unit 52 detects the uplink transmission timing information from the transmission packet from the OLT, and controls the packet transmission timing based on the detected uplink transmission timing information. The packet transmission time zone is determined, power is supplied to the optical transmission unit 4 during the determined transmission time zone, and power is not supplied to the optical transmission unit 4 except for the transmission time. Therefore, unnecessary power consumption can be suppressed, the power consumption of the optical transmitter 4 can be reduced, and the power consumption of the entire apparatus can be reduced.

Embodiment 2. FIG.
FIG. 3 is a diagram showing a functional configuration example of the second embodiment of the ONU 1a according to the present invention. The ONU 1a of the present embodiment is the same as the ONU 1 of the first embodiment except that the PON-LSI 5 of the ONU 1 of the first embodiment is replaced with a PON-LSI 5a. The PON-LSI 5a is the same as the PON-LSI 5 of the first embodiment except that the power supply timing control function unit 53 is added to the PON-LSI 5 of the first embodiment. Components having the same functions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. Hereinafter, a different part from Embodiment 1 is demonstrated.

  In the first embodiment, power is supplied to the optical transmission unit 4 during the packet transmission time period. However, the power source timing control function unit 53 of the present embodiment transmits the transmission packet based on the uplink transmission timing detection information. The power is turned on before a predetermined margin time (hereinafter referred to as a first margin time) before the time at which the optical transmission unit 4 reaches the optical transmitter 4, and a predetermined margin time (hereinafter referred to as a second margin time) after the transmission packet ends. The power supply time zone of the optical transmitter 4 is determined so that the power source is turned off after the elapse of time, and the power source is controlled based on the determined supply time zone. In this way, by setting the margin time, even when data cannot be transmitted at the rise time and the fall time, power is supplied to the optical transmitter 4 in consideration of the rise / fall characteristics. Can do.

  FIG. 4 is a timing chart for explaining the packet sequence received by the ONU 1a of the present embodiment and the power supply status to each functional block. The stages (a) to (d) are the same as those in FIG. 2 of the first embodiment. The stage of “(e) optical transmission unit power supply status” indicates power supply to the optical transmission unit 4, but unlike the first embodiment, the transmission timing is not the same as the transmission timing of “(d) transmission packet sequence”. The front and back are longer than the time zone. The stage of “(f) Transmission packet sequence power ON / OFF timing” includes a transmission time zone of “(d) transmission packet sequence”, a power supply time zone of “(e) optical transmitter power supply”, and The difference is shown.

  Operations other than those described above in the present embodiment are the same as those in the first embodiment. In this embodiment, the margin time is set before and after the transmission time zone, but only one of the front time and the rear time may be set.

  As described above, in this embodiment, the power is turned on from the time before the transmission packet reaches the optical transmission unit 4 by the first margin time, and the power is turned on after the second margin time has elapsed after the transmission packet is completed. I tried to fall. Therefore, it is possible to control the power supply in consideration of the power supply rise / fall characteristics of the optical transmission unit 4. For example, even when inexpensive hardware that cannot emit data immediately after the power is turned on is applied to the optical transmission unit 4, the optical transmission unit Therefore, unnecessary power consumption can be suppressed in accordance with the characteristics of 4, power consumption of the optical transmission unit 4 can be reduced, and power consumption of the entire apparatus can be reduced.

Embodiment 3 FIG.
FIG. 5 is a diagram illustrating a functional configuration example of the third embodiment of the ONU 1b according to the present invention. As shown in FIG. 5, the ONU 1b of the present embodiment adds a delay circuit 7 and an OR (logical sum circuit) 8 to the ONU 1 of the first embodiment, but otherwise the ONU 1 of the first embodiment is the same as the ONU 1 of the first embodiment. It is the same. Components having the same functions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. Hereinafter, a different part from Embodiment 1 is demonstrated.

  In this embodiment, by using the delay circuit 7 and the OR 8 shown in FIG. 5, the power supply to the optical transmitter 4 is started before the packet transmission time without changing the inside of the PON-LSI 5. be able to.

  FIG. 6 is a timing chart for explaining the packet sequence received by the ONU 1b of this embodiment and the power supply status to each functional block. The stages (a) to (c) are the same as those in FIG. 2 of the first embodiment. The stage of “(d) optical output control signal” is a signal for instructing optical output to the optical transmission unit 4 output from the data processing unit 51, and a hatched portion indicates a period in which optical output is instructed. It is. The stage “(e) Optical output control signal (after delay)” shows the optical output control signal after “(d) Optical output control signal” is delayed by the delay circuit 7.

  The stage “(f) Transmission packet sequence (after delay)” indicates a packet sequence output in accordance with an instruction of “(e) Optical output control signal (after delay)”. The stage of “(g) power supply to the optical transmitter” indicates the power supply status to the optical transmitter 4 of the present embodiment. The stage of “(h) Difference between transmission packet sequence and power ON / OFF timing” includes the transmission time zone of “(f) Transmission packet sequence (after delay)” and “(g) Optical transmitter power supply status” The difference from the power supply time zone is shown.

  The operation of this embodiment will be described with reference to FIGS. The uplink transmission timing information detection unit 52 detects uplink timing information from the received packet as in the first embodiment, and determines the transmission timing of the packet transmitted by the own station based on the detected uplink transmission timing information. Then, the data processing unit 51 sends transmission data and an optical output control signal to the delay circuit 7 according to the transmission timing. The optical output control signal at this time is shifted in consideration of a delay by a delay circuit 7 (described later) with respect to the determined transmission timing, and the optical output after the delay is generated if the optical control signal is generated. The control signal follows the instructed transmission timing. The delay circuit 7 delays the light output control signal output from the data processing unit 51 by a predetermined time.

  The OR 8 is an optical output control signal output from the data processing unit 51 (an optical output control signal before being delayed) and an optical output control signal output from the delay circuit 7 (an optical output control signal after being delayed). ) As a power control signal for the optical transmission unit 4 and output to the power supply unit 6. The power supply unit 6 supplies power to the optical transmission unit 4 in accordance with the output power control signal. Operations of the present embodiment other than those described above are the same as those of the first embodiment.

  As described above, in this embodiment, the delay circuit 7 delays the optical output control signal output from the data processing unit 51, and the OR 8 delays the optical output control signal output from the data processing unit 51. A logical sum with the signal is output to the power supply unit 6 as a power supply control signal. Therefore, the power supply to the optical transmission unit 4 can be started before the packet transmission time zone without changing the internal configuration of the PON-LSI 5, and the power consumption of the optical transmission unit 4 can be reduced easily. In addition, the power consumption of the entire apparatus can be reduced.

  As described above, the subscriber termination device and the power supply control method according to the present invention are useful for optical communication systems, and are particularly suitable for PON systems.

It is a figure which shows the function structural example of Embodiment 1 of the subscriber termination | terminus apparatus concerning this invention. It is a timing chart explaining the packet sequence which ONU receives, and the power supply condition to each functional block. It is a figure which shows the function structural example of Embodiment 2 of ONU concerning this invention. 10 is a timing chart for explaining a packet sequence received by the ONU according to the second embodiment and a power supply status to each functional block. It is a figure which shows the function structural example of Embodiment 3 of ONU concerning this invention. 10 is a timing chart for explaining a packet sequence received by an ONU of Embodiment 3 and a power supply status to each functional block.

Explanation of symbols

1 ONU
2 WDM filter 3 Optical receiver 4 Optical transmitter 5, 5a PON-LSI
6 Power supply section 7 Delay circuit 8 OR
51 Data Processing Unit 52 Upstream Transmission Timing Information Detection Unit 53 Power Supply Timing Control Function Unit

Claims (5)

A subscriber termination device comprising optical transmission means for converting transmission data generated as an electrical signal into an optical signal and transmitting the optical signal,
Detects transmission timing information, which is information for instructing the transmission timing of a packet included in the received packet, determines a transmission start time based on the detected transmission timing information, and transmits based on the packet length of transmission data and determining the end time, determines from the start time to the end time as the transmission time period, the determined transmission time band and the transmission data is output to the optical transmission means, based on the determined transmission time band Data processing means for determining a power supply time zone, which is a time for supplying power to the optical transmission means,
Power supply means for supplying power to the optical transmission means based on the power supply time period;
With
The subscriber terminal apparatus characterized in that the optical transmission means transmits the optical signal based on the transmission time zone.   The subscriber termination device according to claim 1, wherein the transmission time zone and the power supply time zone are the same time zone. The data processing means includes
The power supply start time is defined as a power supply start time that is earlier than the start time of the transmission time period by a predetermined start margin time, and the power supply end time is defined as a time that is later than the end time of the transmission time period by a predetermined end margin time. Power supply timing control means that uses the power supply time zone from the power supply end time to
The subscriber termination device according to claim 1, further comprising: A subscriber termination device comprising optical transmission means for converting transmission data generated as an electrical signal into an optical signal and transmitting the optical signal,
Transmission timing information that is information for instructing transmission timing is detected from the received packet, transmission start time is determined based on the detected transmission timing information, and transmission end time is determined based on the packet length of transmission data The transmission time zone is determined from the start time to the end time , transmission data is output to the optical transmission means based on the determined transmission time zone, and an optical signal is transmitted in the transmission time zone. Data processing means for outputting to the optical transmission means an optical output control signal that becomes a first value indicating the instruction of the optical signal and becomes a second value indicating an instruction to stop the optical signal in a time zone other than the transmission time zone;
Delay means for generating a delayed signal obtained by delaying the light output control signal by a predetermined time;
A logical sum of the optical output control signal and the delayed signal is generated, and a period in which the generated logical sum is a first value is a power supply time period in which power is supplied to the optical transmitter. Generating means;
Power supply means for supplying power to the optical transmission means based on the power supply time period;
With
The optical transmission means transmits the optical signal based on the delayed signal. A transmission power control method in a subscriber termination device comprising optical transmission means for converting transmission data generated as an electrical signal into an optical signal and transmitting the optical signal,
Detects transmission timing information, which is information for instructing the transmission timing of a packet included in the received packet, determines a transmission start time based on the detected transmission timing information, and transmits based on the packet length of transmission data and determining the end time, determines from the start time to the end time as the transmission time period, the determined transmission time band and the transmission data is output to the optical transmission means, based on the determined transmission time band A transmission timing information detecting step for determining a power supply time zone that is a time for supplying power to the optical transmission means;
A power supply step of supplying power to the optical transmission means based on the power supply time;
Including
The power control method, wherein the optical transmission means transmits the optical signal based on the transmission time zone.

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