WO2019026281A1 - Optical communication system - Google Patents

Optical communication system Download PDF

Info

Publication number
WO2019026281A1
WO2019026281A1 PCT/JP2017/028414 JP2017028414W WO2019026281A1 WO 2019026281 A1 WO2019026281 A1 WO 2019026281A1 JP 2017028414 W JP2017028414 W JP 2017028414W WO 2019026281 A1 WO2019026281 A1 WO 2019026281A1
Authority
WO
WIPO (PCT)
Prior art keywords
time
unit
reception
extraction unit
radio
Prior art date
Application number
PCT/JP2017/028414
Other languages
French (fr)
Japanese (ja)
Inventor
隆志 西谷
平野 幸男
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2019533864A priority Critical patent/JP6599063B2/en
Priority to PCT/JP2017/028414 priority patent/WO2019026281A1/en
Publication of WO2019026281A1 publication Critical patent/WO2019026281A1/en

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B10/00Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/27Arrangements for networking
    • H04B10/272Star-type networks or tree-type networks
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00Data switching networks
    • H04L12/28Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/44Star or tree networks

Definitions

  • the present invention relates to an optical communication system, and more particularly to an optical communication system for performing optical uplink scheduling for reducing delay time.
  • a terminal performs wireless communication with a base station. Since one base station normally communicates with a plurality of terminals, the base station dynamically allocates a finite communication capacity (hereinafter referred to as a resource) to each terminal so that signals between the terminals do not interfere with each other. Do. For example, when uplink communication in LTE is taken as an example, when a terminal (hereinafter referred to as UE) transmits uplink data to a base station, it first makes a bandwidth request to the base station.
  • a finite communication capacity hereinafter referred to as a resource
  • the base station When the base station receives the bandwidth request, the base station allocates resources for sending such information to the UE in order to obtain information necessary for uplink data scheduling, such as buffer size and channel state, from the UE, to the UE The resource is notified as a response.
  • the UE transmits information necessary for uplink data scheduling to the base station on the allocated resources.
  • the base station performs scheduling using the information, and allocates resources for sending uplink data to the UE with a scheduling grant. Through these exchanges, the UE can send uplink data to the base station for the first time.
  • a wireless system in which a C-RAN configuration has been introduced, in which a base station is separated into a master station apparatus having a wireless modulation / demodulation function and a slave station apparatus having a wireless transmission / reception function.
  • the base station is divided into a master station apparatus and a slave station apparatus, and the master station apparatuses are integrated into one station, whereby cooperation control between slave stations is efficiently realized.
  • the connection between the master station apparatus and the slave station apparatus may be in the form of one-to-many connection using a PON (Passive Optical Network) system.
  • PON Passive Optical Network
  • the master station apparatus and the slave station apparatus are connected by an optical fiber and an optical splitter. According to this configuration, the number of master station devices and the number of optical fibers can be reduced with respect to the number of a plurality of slave station devices, which improves the economic efficiency.
  • one OLT (Optical Line Terminal) communicates with a plurality of ONUs (Optical Network Units). Therefore, the OLT performs scheduling to dynamically allocate communication capacity to each ONU.
  • the ONU first sets the information of the data amount stored in its own transmission buffer (hereinafter referred to as REPORT information) at the timing specified by the transmission permission signal sent from the OLT. , To the OLT.
  • REPORT information the information of the data amount stored in its own transmission buffer
  • the OLT performs scheduling based on REPORT information, allocates a resource for transmitting uplink data to each ONU, and notifies the allocated resource to each ONU. Through these exchanges, each ONU can transmit uplink data to the OLT for the first time.
  • each ONU notifies the OLT of the REPORT information stored in each ONU, a resource is allocated, and uplink data is transmitted. Delay occurs.
  • Patent Document 2 when using the PON system to connect the upper apparatus as a master station and the base station as a slave station, the base station under the ONU transmits uplink to the mobile terminal.
  • the base station under the ONU transmits uplink to the mobile terminal.
  • This invention was made in order to solve such a subject, and the light by which the delay time was reduced by grasping
  • the object is to obtain an optical communication system that enables uplink scheduling.
  • the present invention connects a station-side device connected to a master station device, a terminal-side device connected to a slave station device performing wireless communication with a terminal, the station-side device, and the terminal-side device.
  • An optical transmission path the terminal device receiving wireless data transmission timing information indicating the transmission timing at which the terminal transmits wireless data from the slave station device, and receiving the wireless data transmission timing information
  • a reception time detection unit for detecting a time, and a transmission unit for transmitting a notification frame for notifying the station apparatus of the reception time, the station apparatus performing radio uplink scheduling information managed by the master station apparatus
  • the wireless information extraction unit to be extracted, a time extraction unit to extract the reception time from the notification frame transmitted by the transmission unit, and the wireless based on the reception time extracted by the time extraction unit
  • the terminal side apparatus calculates an estimated reception time for the terminal device to receive data corresponding to the reception scheduling information from the slave station apparatus, and the terminal side based on the estimated reception time and the radio uplink scheduling information.
  • An optical communication system comprising:
  • the terminal device receives the wireless data transmission timing information and notifies the station device of the reception time of the information.
  • the station device By accurately grasping the reception time of data from the station apparatus, it is possible to accurately match the wireless uplink scheduling information managed by the master station apparatus with the optical uplink scheduling information, and as a result, the delay time is reduced. Enables optical uplink scheduling.
  • FIG. 1 is a configuration diagram showing a configuration of an optical communication system according to Embodiment 1 of the present invention.
  • a base station cooperative optical communication system will be described as an example of an optical communication system.
  • the PON system is applied as a connection between the master station apparatus and the slave station apparatus.
  • FIG. 1 shows an example in which a radio frame number and a subframe number of radio data are stored in radio uplink scheduling information included in downlink data from a master station apparatus.
  • the wireless data is composed of a wireless frame consisting of a sequence of subframes.
  • the time length of one subframe is 1 ms
  • the time length of one radio frame is 10 ms. That is, in the case of LTE, one radio frame is configured from ten subframes.
  • FIG. 2 is a figure which shows an example of a structure of the radio
  • a master station device 1 having a wireless modulation / demodulation function and a slave station device 2 having a wireless transmission / reception function are provided.
  • the master station device 1 and the slave station device 2 constitute a base station.
  • An optical subscriber termination device (hereinafter referred to as an OLT) 4 is connected to the master station device 1.
  • the mobile station device 2 performs wireless communication with the wireless terminal (UE) 3.
  • An optical network unit (hereinafter referred to as an ONU) 5 is connected to the slave station device 2.
  • the OLT 4 and the ONU 5 are connected by an optical transmission path 6.
  • the light transmission path 6 is made of, for example, an optical fiber.
  • those ONUs 5 are connected to one OLT 4 via an optical splitter (not shown).
  • the OLT 4 needs to perform scheduling to dynamically allocate the capacity to each ONU, particularly when there are a plurality of ONUs 5.
  • the OLT 4 is referred to as a station-side device because it is disposed on the master station device 1 side.
  • the ONU 5 is disposed on the UE 3 side, it is called a terminal device.
  • the parent station apparatus 1 outputs downlink data including radio uplink scheduling information to the OLT 4.
  • the uplink radio scheduling information includes allocation resource information for instructing each UE 3 the resource allocated by the master station device 1 to each UE 3.
  • the allocation resource is information for instructing each UE 3 in which time zone a subframe is to be transmitted in which time zone.
  • each UE 3 transmits uplink data on the resource instructed by the allocation resource information.
  • the radio uplink scheduling information further includes the radio frame number and the subframe number of the radio data for each mobile station apparatus 2 and for each UE 3.
  • the configuration of the OLT 4 will be described below.
  • the OLT 4 includes a wireless information extraction unit 11, a resource conversion unit 12, a number extraction unit 13, a GPS extraction unit 14, a time extraction unit 15, a time estimation unit 16, an MPCP unit 17, and a time conversion unit 18. , PON scheduler 19, multiplexer (hereinafter referred to as MUX) 20, and optical transmitter / receiver 21.
  • MUX multiplexer
  • the radio information extraction unit 11 extracts radio uplink scheduling information from the downlink data from the master station device 1.
  • the uplink radio scheduling information includes allocation resource information, a radio frame number, and a subframe number.
  • the resource conversion unit 12 searches the amount of uplink data for each UE 3 from the allocation resource information included in the uplink radio scheduling information extracted by the radio information extraction unit 11, and accumulates the data for each ONU 5 that receives uplink data of the UE 3 The amount is calculated and notified to the PON scheduler 19 as light resource information.
  • the number extraction unit 13 extracts the radio frame number and the subframe number from the radio uplink scheduling information extracted by the radio information extraction unit 11 and outputs the radio frame number and the subframe number to the time estimation unit 16.
  • the GPS extraction unit 14 manages an absolute time based on 1 PPS and ToD from the GPS receiver 7 provided outside.
  • the time extraction unit 15 extracts, from the upstream data from the ONU 5, the subframe top notification frame multiplexed into the upstream data.
  • the subframe start notification frame includes a radio frame number, a subframe number, and a subframe start time.
  • the subframe start time means that the ONU 5 receives SUBFRAME. Indicates the reception time at which the indication frame was received. SUBFRAME.
  • the indication frame includes information indicating transmission timing information for the UE 3 to transmit a subframe.
  • the time estimation unit 16 estimates the reception time at which the wireless data indicated by the wireless frame number and the subframe number extracted by the number extraction unit 13 is received by the ONU 5 as an absolute time, and outputs it as the ONU reception time. Specifically, the time estimation unit 16 receives, from the time extraction unit 15, the radio frame number, the subframe number, and the subframe start time included in the subframe start notification frame from the ONU 5. Further, in the time estimation unit 16, a time length of one subframe, which is a system setting value, is stored in advance. Further, the radio frame number and the subframe number extracted by the number extraction unit 13 are input to the time estimation unit 16.
  • the time estimation unit 16 collates the radio frame number and the subframe number extracted by the number extraction unit 13 with the radio frame number and the subframe number included in the top notification frame to obtain the sub From the frame start time, the subframe start time corresponding to the wireless frame number and the subframe number extracted by the number extraction unit 13 is retrieved and obtained, and is output as the ONU reception time.
  • the number extracting unit 13, the time extracting unit 15, and the time estimating unit 16 select the data corresponding to the wireless uplink scheduling information based on the reception time extracted by the time extracting unit 15 as the ONU 5 serving as the terminal device.
  • the estimated time calculation unit configured to calculate the estimated reception time received from the station device 2 is configured.
  • the number extraction unit 13 constitutes a first number extraction unit that extracts a radio frame number and a subframe number from the radio uplink scheduling information.
  • the time extraction unit 15 configures a second number extraction unit that extracts a radio frame number and a subframe number from a subframe top notification frame as a notification frame.
  • the time estimation unit 16 includes the radio frame number and subframe number extracted by the number extraction unit 13 which is a first number extraction unit, the radio frame number extracted by the time extraction unit 15 which is a second number extraction unit, The wireless frame number extracted by the number extraction unit 13 which is the first number extraction unit from among the reception times included in the subframe top notification frame extracted by the time extraction unit 15 by collating with the subframe number And the time estimation part which searches the reception time corresponding to a sub-frame number, and outputs the reception time obtained by the search as ONU reception time which is estimated reception time is comprised.
  • the MPCP unit 17 manages Local Time, which is a system management time of the PON system configured by the OLT 4 and the ONU 5. Also, the MPCP unit 17 generates a control frame (hereinafter referred to as a Gate frame) for notifying resource allocation information to the ONU 5 and transmission permission timing based on optical uplink scheduling information from the PON scheduler 19 described later. .
  • a control frame hereinafter referred to as a Gate frame
  • the time conversion unit 18 sets the ONU reception time represented by the absolute time from the time estimation unit 16 to the Local Time based on the current Local Time managed by the MPCP unit 17 and the absolute time from the GPS extraction unit 14. It converts and outputs as ONU data reception timing. That is, the ONU data reception timing is the ONU reception time represented by Local Time.
  • the ONU reception time output from the time estimation unit 16 is expressed as an absolute time, and therefore can not be used by the PON scheduler 19 as it is.
  • the data that can be used by the PON scheduler 19 needs to be expressed in Local Time, which is the system management time of the PON system, so the time conversion unit 18 converts ONU reception time from absolute time to Local Time time. Processing is in progress.
  • the PON scheduler 19 schedules a resource to be allocated to each ONU 5 from the optical resource information from the resource conversion unit 12 and the ONU data reception timing from the time conversion unit 18 and outputs it as optical uplink scheduling information.
  • the PON scheduler 19 generates optical uplink scheduling information for transmitting data from the terminal device 5 ONU 5 to the station device 2 based on the ONU data reception timing indicating the estimated reception time and the wireless uplink scheduling information. Configuring a scheduling unit.
  • the MUX 20 multiplexes the Gate frame generated by the MPCP unit 17 into downlink data.
  • the optical transmission / reception unit 21 receives uplink data from the ONU 5 and outputs the data to the time extraction unit 15 and the master station device 1. Also, the optical transmission / reception unit 21 outputs the downstream data and the Gate frame multiplexed by the MUX 20 to the ONU 5.
  • the MPCP unit 17, the MUX 20, and the optical transmission / reception unit 21 constitute a notification unit that notifies the ONU 5 which is the terminal side apparatus of the optical uplink scheduling information.
  • the ONU 5 includes a number extraction unit 22, a GPS extraction unit 23, a time detection unit 24, a frame generation unit 25, an MPCP unit 26, a transmission control unit 27, an optical transmission / reception unit 28, and a multiplexing unit (hereinafter, MUX And 29).
  • the number extraction unit 22 uses SUBRAM. Indication frame is extracted, SUBFRAME. The radio frame number and the subframe number included in the indication frame are acquired. The acquired radio frame number and subframe number are output to the frame generation unit 25. In addition, the number extraction unit 22 sets the SUBFRAME. Generate a frame reception trigger indicating reception of an indication frame. The generated frame reception trigger is output to the time detection unit 24.
  • the GPS extraction unit 23 manages an absolute time based on 1 PPS and ToD from the GPS receiver 7 provided outside.
  • the time detection unit 24 uses the frame reception trigger from the number extraction unit 22 and the absolute time from the GPS extraction unit 23 to determine that the ONU 5 is a SUBFRAME.
  • the reception time at which the indication frame is received is detected as an absolute time, and is output as the subframe start time.
  • the number extraction unit 22 and the time detection unit 24 receive the wireless data transmission timing information indicating the transmission timing at which the terminal UE 3 transmits wireless data from the slave station apparatus 2 and receiving the wireless data transmission timing information
  • a reception time detection unit that detects a time is configured.
  • the frame generation unit 25 generates a subframe top notification frame including the radio frame number and subframe number obtained by the number extraction unit 22 and the subframe start time detected by the time detection unit 24.
  • the MPCP unit 26 extracts and processes a Gate frame from the downlink data received from the OLT 4 by the light transmitting / receiving unit 28, and outputs a transmission permission signal indicating transmission permission timing included in the Gate frame.
  • the transmission control unit 27 controls transmission of uplink data and a subframe top notification frame in accordance with the transmission permission timing of the transmission permission signal from the MPCP unit 26.
  • the optical transmission / reception unit 28 transmits the upstream data and the subframe top notification frame to the OLT 4 under the control of the transmission control unit 27.
  • the optical transmission / reception unit 28 also receives downlink data from the OLT 4 and outputs the downlink data to the MPCP unit 26 and the slave station device 2.
  • the frame generation unit 25, the transmission control unit 27, and the optical transmission / reception unit 28 constitute a transmission unit for transmitting a subframe top notification frame as a notification frame for notifying the OLT 4 as the station apparatus of the reception time of the ONU 5 doing.
  • the MUX 29 multiplexes the subframe top notification frame generated by the frame generation unit 25 with uplink data, and outputs the uplink data to the transmission control unit 27.
  • FIG. 5 shows an example of the flow of processing for grasping the subframe start time.
  • step S1 will be described with reference to FIG.
  • the ONU 5 receives uplink data from the slave station device 2.
  • Upstream data includes main signal data and SUBFRAME. and an indication frame.
  • the SUB FRAME Receive indication frame. Therefore, SUBFRAME.
  • the reception time of the indication frame indicates the time when the beginning of the subframe is received. Therefore, here, the time is referred to as a subframe start time.
  • Uplink data received by the ONU 5 is transferred to the number extraction unit 22.
  • the number extraction unit 22 sets the ONU 5 to the SUBFRAME.
  • a frame reception trigger is generated to indicate that an indication frame has been received.
  • the frame reception trigger is output to the time detection unit 24.
  • step S2 The ONU 5 receives a GPS signal (1 PPS, ToD) from an external device such as the GPS receiver 7 or a host device, and the GPS extraction unit 23 grasps an absolute time using the GPS signal. The absolute time is notified to the time detection unit 24.
  • the time detection unit 24 uses the frame reception trigger from the number extraction unit 22 and the absolute time from the GPS extraction unit 23 to set the SUBFRAME. The reception time of the indication frame is detected and notified to the frame generation unit 25 as the subframe start time.
  • step S3 the number extraction unit 22 extracts the radio frame number and the subframe number from the uplink data.
  • the extracted radio frame number and subframe number are notified to the frame generation unit 25.
  • step S4 the frame generation unit 25 uses the radio frame number and subframe number extracted by the number extraction unit 22 and the subframe start time detected by the time detection unit 24 to generate a subframe start notification frame.
  • the subframe start notification frame includes the radio frame number, the subframe number, and the subframe start time.
  • step S5 in the MUX 29, the subframe top notification frame is multiplexed with the uplink data, and transmitted to the transmission control unit 27.
  • the MPCP unit 26 extracts transmission permission timing from the transmission permission signal included in the Gate frame transmitted from the OLT 4.
  • the transmission control unit 27 transmits the multiplexed uplink data and the subframe top notification frame to the OLT 4 in accordance with the transmission permission timing.
  • FIG. 6 shows an example of the flow of processing for grasping the subframe start time.
  • step S11 the OLT 4 receives, from the ONU 5, a subframe top notification frame multiplexed into upstream data.
  • the subframe top notification frame is input to the time extraction unit 15.
  • the time extraction unit 15 extracts a subframe top notification frame.
  • step S12 the time extraction unit 15 extracts the radio frame number, the subframe number, and the subframe start time stored in the subframe start notification frame, and notifies the time estimation unit 16 of them.
  • the time estimation unit 16 obtains the subframe start time corresponding to the radio frame number and the subframe number of the OLT 4 and updates the ONU reception time. Specifically, the time estimation unit 16 collates the radio frame number and the subframe number extracted by the number extraction unit 13 with the radio frame number and the subframe number extracted by the time extraction unit 15 to obtain a time extraction unit. The subframe start time corresponding to the radio frame number and subframe number extracted by the number extraction unit 13 is searched from among the subframe start times extracted at 15. The time estimation unit 16 outputs the subframe start time obtained by the search as an estimated value of the reception time in the ONU 5.
  • the estimated value is referred to as ONU reception time.
  • steps S11 to S13 are performed for each ONU 5 connected to the OLT 4.
  • the OLT 4 it becomes possible for the OLT 4 to accurately grasp, for each ONU 5, the subframe start time that arrives at the ONU 5 from the slave station device 2.
  • This sub-frame start time is a value obtained by the frame reception trigger in the ONU 5 and thus is an actually measured reception time. Therefore, the processing delay of the slave station 2, the processing delay of the ONU 5, and the deviation due to the transmission delay between the slave station 2 and the ONU 5 are included.
  • the accurate reception time can be acquired by obtaining the reception time including the deviation by the frame reception trigger. By notifying the OLT 4 of the accurate reception time thus obtained, the OLT 4 can also grasp the accurate reception time.
  • FIG. 7 shows an example of the flow of the optical uplink scheduling process for the ONU 5 using the subframe start time.
  • downlink data including radio uplink scheduling information is transmitted from the master station device 1 to the OLT 4.
  • the downlink data received by the OLT 4 is input to the wireless information extraction unit 11.
  • the radio information extraction unit 11 extracts a radio main signal and radio uplink scheduling information from the downlink data.
  • the radio uplink scheduling information stores radio frame numbers and subframe numbers as slave station reception timing information for each slave station apparatus 2 and for each UE 3 as shown in FIG. 2, and RIV, MCS as allocation resource information. Is stored.
  • RIV is described as RBA
  • MCS is described as M # 1 and M # 2.
  • the extracted radio uplink scheduling information is transferred to the resource conversion unit 12 and the number extraction unit 13 respectively.
  • the number extraction unit 13 extracts the radio frame number and the subframe number for each mobile station apparatus 2 and for each UE 3 from the radio uplink scheduling information.
  • the extracted radio frame number and subframe number are transferred to the time estimation unit 16.
  • step S22 the resource conversion unit 12 extracts allocation resource information for each UE 3 from the uplink radio scheduling information, and calculates an uplink data amount from the extracted allocation resource information for each UE 3. The calculated amount of uplink data is notified to the PON scheduler 19.
  • step S23 the time estimation unit 16 uses the radio frame number, the subframe number, the subframe start time, and the time length of one subframe which is a system setting value, included in the subframe start notification frame from the ONU 5.
  • the subframe start time corresponding to the radio frame number and the subframe number extracted by the number extraction unit 13 is determined from the subframe start times included in the subframe start notification frame, and the subframe start time is determined as the time. It rearranges in order, and outputs it to the time conversion part 18 as ONU reception time.
  • step S24 the time conversion unit 18 converts the ONU reception time from an absolute time expression to a local time expression using the current Local Time managed by the MPCP unit 17 and the absolute time from the GPS extraction unit 14. Thus, the ONU data reception timing is obtained. The ONU reception timing is output to the PON scheduler 19.
  • the PON scheduler 19 performs optical uplink scheduling for each ONU 5 from the ONU data reception timing for each slave station apparatus 2 and for each UE 3 and the amount of uplink data included in the optical resource information, It notifies the MPCP unit 17. At this time, since the ONU data reception timing does not include the deviation due to the round trip delay time between the OLT 4 and the ONU 5, the PON scheduler 19 performs the optical uplink scheduling in consideration of the round trip delay time between the OLT 4 and the ONU 5 as well. Is more desirable.
  • the MPCP unit 17 generates a Gate frame based on the optical uplink scheduling information, and notifies the ONU 5 of it.
  • the Gate frame includes a transmission permission signal indicating a transmission permission timing for permitting the ONU 5 to transmit uplink data to the OLT 4.
  • steps S25 to S29 will be described.
  • the processes of steps S25 to S29 are repeatedly performed for each preset allocation cycle.
  • step S25 the PON scheduler 19 stores all data from the UE 3 simultaneously received by the slave station device 2 according to the system setting value, obtains the number of frames to be transmitted to the ONU 5, and sets it as N [i].
  • step S26 the PON scheduler 19 obtains the frame length of N [i] frames from the system design value and the amount of data for each UE3.
  • step S27 the data reception time is converted to the frame transmission start time of N [i] frames of the slave station apparatus 2 according to the RTT of the ONU 5 and the external network apparatus configuration information.
  • the PON scheduler 19 executes the processing of steps S 25 to S 27 for each ONU 5 connected to the OLT 4. Then, when the process of steps S25 to S27 is completed for all ONUs 5, the process proceeds to step S28.
  • step S28 the PON scheduler 19 adds the overhead generated in the PON section based on the total number of transmission start times of N [i] and the frame length, and assigns the transmission permission of all ONUs 5.
  • step S29 the PON scheduler 19 allocates a surplus bandwidth to all ONUs 5 for uplink data generated independently of the optical uplink scheduling information.
  • FIG. 8 and FIG. 9 hardware configuration examples of the OLT 4 and the ONU 5 for realizing the first embodiment are shown in FIG. 8 and FIG. 9, respectively.
  • the functions of the respective units of the OLT 4 and the ONU 5 shown in FIG. 1 are realized by a processing circuit.
  • the processing circuit may be, for example, a single circuit, a complex circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.
  • FIG. 10 and FIG. 10 Another example of the hardware configuration of the OLT 4 and the ONU 5 for realizing the first embodiment is shown in FIG. 10 and FIG.
  • the processing circuit is a CPU
  • the functions of the respective units of the OLT 4 and the ONU 5 shown in FIG. 1 are realized by software, firmware, or a combination thereof.
  • Software and firmware are described as programs and stored in memory.
  • the processor that configures the processing circuit implements the functions of the above-described units by reading and executing the program stored in the memory.
  • the respective functions may be partially realized by dedicated hardware and partially realized by software or firmware. Further, the configurations of the OLT 4 and the ONU 5 may be combined with FIGS. In this way, the processing circuit can realize the above-described functions by hardware, software, firmware, or a combination thereof.
  • SUBFRAME The radio uplink scheduling information for each UE 3 and each slave station 2 managed by the master station device 1 by the reception of the indication frame and the notification of the reception time of the frame to the OLT 4 and the optical uplink scheduling information in the PON
  • the terminal side device ONU 5 is a wireless data transmission timing information indicating the transmission timing at which the UE 3 transmits wireless data. Indication frame is received from the slave station device 2, and the number extraction unit 22 and the time detection unit 24 that detect the reception time when the frame is received, and subframe start notification that notifies the OLT 4 that is the station side device And a transmitter (25, 27 and 28) for generating and transmitting a frame.
  • the OLT 4 which is a station-side device, transmits a radio information extraction unit 11 that extracts radio uplink scheduling information managed by the parent station device 1, and a subframe top notification frame that is transmitted by the transmission units (25, 27 and 28).
  • the estimated value of the reception time at which the ONU 5 receives the wireless data corresponding to the wireless uplink scheduling information from the slave station apparatus 2 PON for generating optical uplink scheduling information for data transmission from ONU 5 to OLT 4 based on the estimated time calculation unit (13, 15, and 16) to be calculated and the estimated value of reception time and wireless uplink scheduling information
  • ONU 5 receives SUBFRAME.
  • the OLT 4 can accurately grasp the reception time at the ONU 5 including the deviation between the station apparatus 1 and the OLT 4 due to the transmission delay.
  • resource allocation for reducing the wireless data storage time in the ONU 5 becomes possible, and the wireless uplink scheduling information for each UE 3 and each slave station 2 managed by the master station device 1 and the optical uplink scheduling information in the PON It can be matched exactly.
  • the optical uplink scheduling in which the delay time of transmission of uplink data is suppressed by the OLT 4 accurately grasping the reception time of data from the slave station device 2 in the ONU 5 in wireless communication. make it possible.
  • the radio uplink scheduling information includes the radio frame number and the subframe number of the radio data.
  • the estimated time calculation unit (13, 15, 16) extracts the radio frame number and the subframe number from the radio uplink scheduling information, the number extraction unit 13 and the subframe start notification frame, the radio frame The time extraction unit 15 as a second number extraction unit for extracting numbers and subframe numbers, the radio frame number and subframe number extracted by the number extraction unit 13, and the radio frame number and subframes extracted by the time extraction unit 15
  • the reception time at the ONU 5 of the wireless data corresponding to the wireless frame number and the subframe number extracted by the number extraction unit 13 is searched from the reception times extracted by the time extraction unit 15 by collating with the numbers.
  • the time estimation part 16 which calculates reception time as an estimated value of reception time.
  • the wireless uplink scheduling information includes the wireless frame number and the subframe number of the wireless data
  • the OLT 4 searches for the reception time at the ONU 5 based on those numbers. Since the ONU reception time can be estimated based on the reception time, the ONU reception time can be easily and accurately obtained by simple processing.
  • the wireless uplink scheduling information from the master station apparatus 1 includes the wireless frame number and the subframe number is shown, but in the second embodiment, the wireless uplink scheduling information is The case where the mobile station device 2 includes the information on the reception time when the wireless data is received from the UE 3 will be described.
  • FIG. 3 is a block diagram showing the configuration of the optical communication system according to the second embodiment.
  • the configuration of the ONU 5 is the same as the configuration of the ONU 5 of FIG.
  • the configuration of the OLT 4 is different from that of the OLT 4 of FIG. Specifically, in FIG. 3, a time extracting unit 30 and a time correcting unit 31 are provided instead of the number extracting unit 13 and the time estimating unit 16 in FIG. Further, in FIG. 3, a time conversion unit 18A is provided instead of the time conversion unit 18 in FIG. 1.
  • the other configuration of the OLT 4 is the same as that of FIG.
  • the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted here.
  • the time extraction unit 30 extracts, from the wireless uplink scheduling information extracted by the wireless information extraction unit 11, the reception time at which the mobile station device 2 receives the wireless data from the UE 3.
  • the reception time here is expressed in absolute time.
  • the reception time is referred to as a slave station reception absolute time.
  • the time correction unit 31 corrects the slave station reception absolute time based on the slave station reception absolute time extracted by the time extraction unit 30 and the subframe start time extracted by the time extraction unit 15, and the ONU reception time is corrected. Calculate the ONU reception time correction value to obtain.
  • the time converter 18A includes the slave station reception absolute time from the time extractor 30, the current Local Time managed by the OLT 4, the absolute time from the GPS extractor 14, and the time correction value from the time corrector 31. Is input.
  • the time conversion unit 18A corrects the slave station reception absolute time using the ONU reception time correction value to obtain an estimated value of the reception time when the ONU 5 receives the wireless data from the slave station apparatus 2 as the ONU reception time.
  • the time conversion unit 18A converts the ONU reception time represented by the absolute time into the Local Time, Output as ONU data reception timing.
  • the time extraction unit 30, the time correction unit 31, and the time conversion unit 18A determine the data corresponding to the radio uplink scheduling information on the terminal side.
  • the estimated time calculation unit is configured to calculate an ONU reception time that is an estimated reception time that the ONU 5 that is a device receives from the slave station apparatus 2.
  • the time extraction unit 30 configures a slave station time extraction unit that extracts a slave station reception time from the wireless uplink scheduling information.
  • the time correction unit 31 constitutes a time correction unit which obtains a difference time between the reception time extracted by the time extraction unit 15 and the slave station reception time, and outputs the difference as a time correction value.
  • the time conversion unit 18A configures a time calculation unit that calculates ONU data reception timing indicating the estimated reception time by correcting the slave station reception time based on the time correction value.
  • Downlink data including radio uplink scheduling information is transmitted from the master station device 1 to the OLT 4.
  • the received downlink data is input to the wireless information extraction unit 11.
  • the radio information extraction unit 11 extracts a radio main signal and radio uplink scheduling information from the downlink data.
  • the wireless uplink scheduling information as shown in FIG. 4, as the slave station reception timing for each slave station device 2 and for each UE 3, data reception absolute time at the slave station device 2 is stored, and as allocated resources, RIV and MCS are stored.
  • the wireless uplink scheduling information extracted by the wireless information extraction unit 11 is output to the resource conversion unit 12 and the time extraction unit 30.
  • the time extraction unit 30 extracts a slave station reception absolute time for each slave station device 2 and each UE 3 from the wireless uplink scheduling information.
  • the extracted slave station reception absolute time is output to the time correction unit 31.
  • the time correction unit 31 predicts the subframe start time several cycles ahead from the subframe start time notified from the ONU 5 and the time length of one subframe.
  • the time correction unit 31 compares the predicted subframe start time several cycles ahead with the mobile station reception absolute time from the time extraction unit 30, and the maximum subframe not exceeding the mobile station reception absolute time
  • the difference time between the start time and the slave station reception absolute time is calculated as the ONU reception time correction value.
  • the time length of one subframe is a system setting value, and is, for example, 1 ms in the case of LTE.
  • the ONU reception time correction value calculated by the time correction unit 31 is notified to the time conversion unit 18A.
  • the time conversion unit 18A first calculates the ONU reception time at which the ONU 5 receives data from the slave station apparatus 2 by adding the ONU reception time correction value and correcting the slave station reception absolute time. Next, the time conversion unit 18A converts the obtained ONU reception time into Local Time from the current Local Time managed by the OLT 4 and the absolute time from the GPS extraction unit 14, and outputs it as ONU data reception timing. The ONU data reception timing is notified to the PON scheduler 19. On the other hand, the resource conversion unit 12 calculates the amount of uplink data from the allocation resource included in the wireless uplink scheduling information, and notifies the PON scheduler 19 of the amount.
  • the PON scheduler 19 takes into consideration the ONU data reception timing and upstream data amount converted to Local Time for each slave station device 2 and for each UE 3, and also takes into consideration the round trip delay time between the OLT 4 and the ONU 5, to thereby perform the optical uplink
  • the scheduling is performed and notified to the MPCP unit 17. Since the process of the PON scheduler 19 is the same as the process described in the first embodiment, the detailed description is omitted here.
  • the MPCP unit 17 generates a Gate frame on the basis of the optical uplink scheduling information and notifies the ONU 5 of it.
  • the ONU 5 receives SUBFRAME.
  • the OLT 4 can accurately grasp the reception time at the ONU 5 including the deviation between the station apparatus 1 and the OLT 4 due to the transmission delay.
  • resource allocation for reducing the wireless data storage time in the ONU 5 becomes possible, and the wireless uplink scheduling information for each UE 3 and each slave station 2 managed by the master station device 1 and the optical uplink scheduling information in the PON It can be matched exactly.
  • the optical uplink scheduling in which the delay time of transmission of uplink data is suppressed by the OLT 4 accurately grasping the reception time of data from the slave station device 2 in the ONU 5 in wireless communication. make it possible.
  • the wireless uplink scheduling information is the slave station reception absolute time
  • the wireless uplink for each UE 3 and slave station 2 managed by the master station 1 is also possible.
  • the scheduling and the optical uplink scheduling information in PON can be compared with SUBFRAME.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computing Systems (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Small-Scale Networks (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Optical Communication System (AREA)

Abstract

In an optical communication system pertaining to the present invention, an ONU 5 receives a SUBFRAME.indication frame from a slave station device 2. A time detection unit 24 detects a subframe start time for the frame on the basis of a frame reception trigger indicating the reception of the frame. A frame generation unit 25 generates a notification frame for notifying an OLT 4 of the subframe start time. On the basis of the notification frame, the OLT 4 performs optical uplink scheduling by accurately matching, with optical uplink scheduling information in a PON, radio uplink scheduling information for each UE 3 and slave station device 2 managed by a master station device 1 and notifies the ONU 5.

Description

光通信システムOptical communication system
 この発明は、光通信システムに関し、特に、遅延時間の低減を図る光上りスケジューリングを行うための光通信システムに関する。 The present invention relates to an optical communication system, and more particularly to an optical communication system for performing optical uplink scheduling for reducing delay time.
 LTE(Long Term Evolution)などの無線通信システムにおいて、端末は基地局と無線通信を行う。通常1つの基地局は複数の端末と通信を行っているので、端末同士の信号が混信しないよう、基地局は有限の通信容量(以下、リソースとする)を各端末に動的に割り当てるスケジューリングを行う。例えばLTEの上り通信を例にとると、端末(以下、UEとする)は、上りデータを基地局に送る場合に、まず、基地局に対して帯域要求を行う。基地局は、当該帯域要求を受けると、バッファ量およびチャネル状態などの、上りデータのスケジューリングに必要な情報をUEから得るために、UEにこれらの情報を送るためのリソースを割り当て、UEに対して当該リソースをレスポンスとして通知する。UEは、割り当てられたリソースで、上りデータのスケジューリングに必要な情報を基地局に送信する。基地局は、当該情報を用いてスケジューリングを行い、上りデータを送るためのリソースをスケジューリンググラントによりUEに割り当てる。これらのやりとりを経て、UEは初めて上りデータを基地局に送ることができる。 In a wireless communication system such as LTE (Long Term Evolution), a terminal performs wireless communication with a base station. Since one base station normally communicates with a plurality of terminals, the base station dynamically allocates a finite communication capacity (hereinafter referred to as a resource) to each terminal so that signals between the terminals do not interfere with each other. Do. For example, when uplink communication in LTE is taken as an example, when a terminal (hereinafter referred to as UE) transmits uplink data to a base station, it first makes a bandwidth request to the base station. When the base station receives the bandwidth request, the base station allocates resources for sending such information to the UE in order to obtain information necessary for uplink data scheduling, such as buffer size and channel state, from the UE, to the UE The resource is notified as a response. The UE transmits information necessary for uplink data scheduling to the base station on the allocated resources. The base station performs scheduling using the information, and allocates resources for sending uplink data to the UE with a scheduling grant. Through these exchanges, the UE can send uplink data to the base station for the first time.
 一方で、基地局を、無線変復調機能を持った親局装置と無線送受信機能を持った子局装置とに分離した、C-RAN構成が導入された無線システムが提案されている。当該無線システムでは、基地局を親局装置と子局装置とに分離して、親局装置を1つの局に集約することで、子局間の連携制御を効率的に実現している。このような無線システムにおいて、親局装置と子局装置との間の接続形態としては、PON(Passive Optical Network)システムを利用した1対多接続の形態をとることもできる。この場合、親局装置と子局装置との間を光ファイバと光スプリッタとで接続する。この構成により、複数の子局装置の個数に対する親局装置の個数、および、光ファイバの本数を減らすことができ、経済性が向上する。 On the other hand, there has been proposed a wireless system in which a C-RAN configuration has been introduced, in which a base station is separated into a master station apparatus having a wireless modulation / demodulation function and a slave station apparatus having a wireless transmission / reception function. In the wireless system, the base station is divided into a master station apparatus and a slave station apparatus, and the master station apparatuses are integrated into one station, whereby cooperation control between slave stations is efficiently realized. In such a wireless system, the connection between the master station apparatus and the slave station apparatus may be in the form of one-to-many connection using a PON (Passive Optical Network) system. In this case, the master station apparatus and the slave station apparatus are connected by an optical fiber and an optical splitter. According to this configuration, the number of master station devices and the number of optical fibers can be reduced with respect to the number of a plurality of slave station devices, which improves the economic efficiency.
 PONシステムにおいても、1つのOLT(Optical Line Terminal)は、複数のONU(Optical Network Unit)と通信を行う。そのため、OLTは、通信容量を各ONUに動的に割り当てるスケジューリングを行っている。スケジューリングを行う際には、ONUは、最初に、自身の送信バッファに蓄積されているデータ量の情報(以下、REPORT情報とする)を、OLTから送られてくる送信許可信号が指定したタイミングで、OLTに送信する。OLTは、REPORT情報をもとに、スケジューリングを行い、上りデータを送信するためのリソースを各ONUに割り当てて、割り当てたリソースを、各ONUに通知する。これらのやりとりを経て、各ONUは、はじめて、上りデータをOLTに送信することができる。しかし、親局装置と子局装置との接続形態としてPONシステムを用いた場合、各ONUに蓄積されているREPORT情報を各ONUがOLTに通知して、リソースが割り当てられ、上りデータが送信されるまでの遅延が発生する。 Also in the PON system, one OLT (Optical Line Terminal) communicates with a plurality of ONUs (Optical Network Units). Therefore, the OLT performs scheduling to dynamically allocate communication capacity to each ONU. When performing scheduling, the ONU first sets the information of the data amount stored in its own transmission buffer (hereinafter referred to as REPORT information) at the timing specified by the transmission permission signal sent from the OLT. , To the OLT. The OLT performs scheduling based on REPORT information, allocates a resource for transmitting uplink data to each ONU, and notifies the allocated resource to each ONU. Through these exchanges, each ONU can transmit uplink data to the OLT for the first time. However, when the PON system is used as a connection form between the master station device and the slave station device, each ONU notifies the OLT of the REPORT information stored in each ONU, a resource is allocated, and uplink data is transmitted. Delay occurs.
 C-RAN実現には、親局装置と子局装置との間のデータ転送遅延を低減する必要がある。親局装置と子局装置との接続形態としてPONシステムを用いた場合の遅延を削減する手法として、例えば、特許文献1に記載の方法がある。FDD方式においては、無線スケジューラが、必ず、アンテナが受信する4msほど前に無線上りスケジューリング情報を送信するので、特許文献1では、そのことを利用して、光スケジューラが、帯域を割り当てている。 In C-RAN implementation, it is necessary to reduce the data transfer delay between the master station device and the slave station device. As a method of reducing the delay in the case of using a PON system as a connection form between a master station device and a slave station device, there is, for example, a method described in Patent Document 1. In the FDD scheme, since the wireless scheduler always transmits the wireless uplink scheduling information about 4 ms before the antenna receives, in Patent Document 1, the optical scheduler assigns a band using that.
 また、例えば特許文献2では、親局としての上位装置と子局としての基地局との接続にPONシステムを利用する場合に、ONUの配下にある基地局が、モバイル端末に対して、上り送信許可を与える際に、ONUにも同様の上り送信許可情報を与えることで、低遅延化を実現する手法が提案されている。 Also, for example, in Patent Document 2, when using the PON system to connect the upper apparatus as a master station and the base station as a slave station, the base station under the ONU transmits uplink to the mobile terminal. There is proposed a method for achieving low delay by giving the same upstream transmission permission information to the ONU when giving permission.
国際公開第2014/077168号International Publication No. 2014/077168 特許第5878991号公報Patent No. 5878991
 遅延を低下させた無線上りデータの転送には、光上りスケジューリングタイミングと無線上りスケジューリングタイミングとを同期させる必要がある。上記の特許文献1および特許文献2に記載の従来技術では、無線スケジューリング情報を受信したタイミングを基準として光リソースを割り当てている。しかしながら、当該従来技術では、無線スケジューリング情報の受信タイミングとサブフレーム先頭タイミングとの間には、親局内、子局内、ONU内、及び、OLT内での処理遅延に起因した、または、子局-ONU間、及び、親局-OLT間の伝送遅延に起因した、数十us~1msオーダーのずれが発生する可能性がある。その場合、光上りスケジューリングが正確に行えず、上り遅延時間が増大するという課題があった。 In order to transfer the wireless uplink data whose delay has been reduced, it is necessary to synchronize the optical uplink scheduling timing with the wireless uplink scheduling timing. In the prior art described in Patent Document 1 and Patent Document 2 described above, light resources are allocated based on the timing at which the wireless scheduling information is received. However, in the related art, between the reception timing of the wireless scheduling information and the subframe start timing, due to the processing delay in the master station, in the slave station, in the ONU, and in the OLT, or Deviations of several tens us to 1 ms may occur due to the transmission delay between the ONUs and between the master station and the OLT. In this case, there is a problem that the uplink uplink time can not be accurately performed and the uplink delay time is increased.
 この発明は、かかる課題を解決するためになされたものであり、局側装置において、端末側装置における子局装置からのデータの受信時刻を正確に把握することで、遅延時間を低減させた光上りスケジューリングを可能にする、光通信システムを得ることを目的としている。 This invention was made in order to solve such a subject, and the light by which the delay time was reduced by grasping | ascertaining correctly the reception time of the data from the slave station apparatus in the terminal side apparatus in the station side apparatus The object is to obtain an optical communication system that enables uplink scheduling.
 この発明は、親局装置に接続された局側装置と、端末との間で無線通信を行う子局装置に接続された端末側装置と、前記局側装置と前記端末側装置とを接続する光伝送路とを備え、前記端末側装置は、前記端末が無線データを送信する送信タイミングを示す無線データ送信タイミング情報を前記子局装置から受信して、前記無線データ送信タイミング情報を受信した受信時刻を検出する受信時刻検出部と、前記受信時刻を前記局側装置に通知する通知フレームを送信する送信部とを備え、前記局側装置は、前記親局装置が管理する無線上りスケジューリング情報を抽出する無線情報抽出部と、前記送信部が送信する前記通知フレームから前記受信時刻を抽出する時刻抽出部と、前記時刻抽出部が抽出した前記受信時刻に基づいて、前記無線上りスケジューリング情報に対応するデータを前記端末側装置が前記子局装置から受信する推定受信時刻を算出する推定時刻算出部と、前記推定受信時刻と前記無線上りスケジューリング情報とに基づいて、前記端末側装置から前記局側装置へデータ送信を行うための光上りスケジューリング情報を生成するスケジューリング部と、前記光上りスケジューリング情報を前記端末側装置に通知する通知部とを備えた、光通信システムである。 The present invention connects a station-side device connected to a master station device, a terminal-side device connected to a slave station device performing wireless communication with a terminal, the station-side device, and the terminal-side device. An optical transmission path, the terminal device receiving wireless data transmission timing information indicating the transmission timing at which the terminal transmits wireless data from the slave station device, and receiving the wireless data transmission timing information A reception time detection unit for detecting a time, and a transmission unit for transmitting a notification frame for notifying the station apparatus of the reception time, the station apparatus performing radio uplink scheduling information managed by the master station apparatus The wireless information extraction unit to be extracted, a time extraction unit to extract the reception time from the notification frame transmitted by the transmission unit, and the wireless based on the reception time extracted by the time extraction unit The terminal side apparatus calculates an estimated reception time for the terminal device to receive data corresponding to the reception scheduling information from the slave station apparatus, and the terminal side based on the estimated reception time and the radio uplink scheduling information. An optical communication system comprising: a scheduling unit configured to generate optical uplink scheduling information for transmitting data from an apparatus to the station-side device; and a notification unit configured to notify the terminal-side device of the optical uplink scheduling information.
 この発明に係る光通信システムによれば、端末側装置で無線データ送信タイミング情報を受信して、当該情報の受信時刻を局側装置に通知することで、局側装置において、端末側装置における子局装置からのデータの受信時刻を正確に把握することで、親局装置が管理する無線上りスケジューリング情報と光上りスケジューリング情報とを正確に合致させることができ、その結果、遅延時間を低減させた光上りスケジューリングを可能にする。 According to the optical communication system according to the present invention, the terminal device receives the wireless data transmission timing information and notifies the station device of the reception time of the information. By accurately grasping the reception time of data from the station apparatus, it is possible to accurately match the wireless uplink scheduling information managed by the master station apparatus with the optical uplink scheduling information, and as a result, the delay time is reduced. Enables optical uplink scheduling.
この発明の実施の形態1に係る光通信システムの構成を示す構成図である。It is a block diagram which shows the structure of the optical communication system which concerns on Embodiment 1 of this invention. この発明の実施の形態1に係る光通信システムにおける無線フレームの構成を示した図である。It is the figure which showed the structure of the radio | wireless frame in the optical communication system which concerns on Embodiment 1 of this invention. この発明の実施の形態2に係る光通信システムの構成を示す構成図である。It is a block diagram which shows the structure of the optical communication system which concerns on Embodiment 2 of this invention. この発明の実施の形態2に係る光通信システムにおける無線フレームの構成を示した図である。It is the figure which showed the structure of the radio | wireless frame in the optical communication system which concerns on Embodiment 2 of this invention. この発明の実施の形態1に係る光通信システムにおける処理の流れを示すフローチャートである。It is a flowchart which shows the flow of the process in the optical communication system which concerns on Embodiment 1 of this invention. この発明の実施の形態1に係る光通信システムにおける処理の流れを示すフローチャートである。It is a flowchart which shows the flow of the process in the optical communication system which concerns on Embodiment 1 of this invention. この発明の実施の形態1に係る光通信システムにおける処理の流れを示すフローチャートである。It is a flowchart which shows the flow of the process in the optical communication system which concerns on Embodiment 1 of this invention. この発明の実施の形態1に係る光通信システムにおけるOLTのハードウェア構成を示した構成図である。It is the block diagram which showed the hardware constitutions of OLT in the optical communication system concerning Embodiment 1 of this invention. この発明の実施の形態1に係る光通信システムにおけるONUのハードウェア構成を示した構成図である。It is the block diagram which showed the hardware constitutions of ONU in the optical communication system concerning Embodiment 1 of this invention. この発明の実施の形態1に係る光通信システムにおけるOLTのハードウェア構成を示した構成図である。It is the block diagram which showed the hardware constitutions of OLT in the optical communication system concerning Embodiment 1 of this invention. この発明の実施の形態1に係る光通信システムにおけるONUのハードウェア構成を示した構成図である。It is the block diagram which showed the hardware constitutions of ONU in the optical communication system concerning Embodiment 1 of this invention.
 実施の形態1.
 図1は、この発明の実施の形態1に係る光通信システムの構成を示した構成図である。実施の形態1においては、光通信システムとして、基地局連携光通信システムを例に挙げて説明する。実施の形態1では、親局装置と子局装置との間の接続形態として、PONシステムを適用させている。
Embodiment 1
FIG. 1 is a configuration diagram showing a configuration of an optical communication system according to Embodiment 1 of the present invention. In the first embodiment, a base station cooperative optical communication system will be described as an example of an optical communication system. In the first embodiment, the PON system is applied as a connection between the master station apparatus and the slave station apparatus.
 図1は、親局装置からの下りデータに含まれる無線上りスケジューリング情報に、無線データの無線フレーム番号及びサブフレーム番号を格納した場合の例を示す。無線データは、複数のサブフレームのシーケンスからなる無線フレームから構成されている。例えば、LTEの場合、1サブフレームの時間長は1msで、1無線フレームの時間長は10msである。すなわち、LTEの場合には、10個のサブフレームから1個の無線フレームが構成されている。また、図2は、親局装置が管理する無線上りスケジューリング情報の構成の一例を示す図である。 FIG. 1 shows an example in which a radio frame number and a subframe number of radio data are stored in radio uplink scheduling information included in downlink data from a master station apparatus. The wireless data is composed of a wireless frame consisting of a sequence of subframes. For example, in the case of LTE, the time length of one subframe is 1 ms, and the time length of one radio frame is 10 ms. That is, in the case of LTE, one radio frame is configured from ten subframes. Moreover, FIG. 2 is a figure which shows an example of a structure of the radio | wireless uplink scheduling information which a master station apparatus manages.
 図1において、無線変復調機能を有する親局装置1と、無線送受信機能を持った子局装置2とが設けられている。親局装置1と子局装置2とは、基地局を構成している。親局装置1には、光加入者終端装置(以下、OLTとする)4が接続されている。子局装置2は、無線端末(UE)3との間で、無線通信を行う。子局装置2には、光ネットワークユニット(以下、ONUとする)5が接続されている。OLT4とONU5とは、光伝送路6により接続されている。光伝送路6は、例えば、光ファイバから構成されている。なお、図1においては、1個のONU5のみが図示されているが、実際には、複数のONU5が設けられている。その場合には、それらのONU5は、光スプリッタ(図示せず)を介して、1つのOLT4に接続される。OLT4は、特に、ONU5が複数の場合に、容量を各ONUに動的に割り当てるスケジューリングを行う必要がある。OLT4は、親局装置1側に配置されているため、局側装置と呼ばれる。一方、ONU5は、UE3側に配置されているため、端末側装置と呼ばれる。 In FIG. 1, a master station device 1 having a wireless modulation / demodulation function and a slave station device 2 having a wireless transmission / reception function are provided. The master station device 1 and the slave station device 2 constitute a base station. An optical subscriber termination device (hereinafter referred to as an OLT) 4 is connected to the master station device 1. The mobile station device 2 performs wireless communication with the wireless terminal (UE) 3. An optical network unit (hereinafter referred to as an ONU) 5 is connected to the slave station device 2. The OLT 4 and the ONU 5 are connected by an optical transmission path 6. The light transmission path 6 is made of, for example, an optical fiber. Although only one ONU 5 is illustrated in FIG. 1, in actuality, a plurality of ONUs 5 are provided. In that case, those ONUs 5 are connected to one OLT 4 via an optical splitter (not shown). The OLT 4 needs to perform scheduling to dynamically allocate the capacity to each ONU, particularly when there are a plurality of ONUs 5. The OLT 4 is referred to as a station-side device because it is disposed on the master station device 1 side. On the other hand, since the ONU 5 is disposed on the UE 3 side, it is called a terminal device.
 親局装置1は、無線上りスケジューリング情報を含む下りデータをOLT4に対して出力する。無線上りスケジューリング情報には、親局装置1が各UE3に対して割り当てたリソースを各UE3に対して指示する割当リソース情報が含まれる。割当リソースは、各UE3に対してどの時間帯にどの周波数帯域でサブフレームを送信するかを指示する情報である。各UE3は、親局装置1に対して上りデータを送信する際には、割当リソース情報で指示されたリソースで上りデータを送信する。また、上述したように、無線上りスケジューリング情報には、さらに、子局装置2毎、UE3毎の、無線データの無線フレーム番号およびサブフレーム番号が含まれている。 The parent station apparatus 1 outputs downlink data including radio uplink scheduling information to the OLT 4. The uplink radio scheduling information includes allocation resource information for instructing each UE 3 the resource allocated by the master station device 1 to each UE 3. The allocation resource is information for instructing each UE 3 in which time zone a subframe is to be transmitted in which time zone. When transmitting uplink data to the master station device 1, each UE 3 transmits uplink data on the resource instructed by the allocation resource information. Further, as described above, the radio uplink scheduling information further includes the radio frame number and the subframe number of the radio data for each mobile station apparatus 2 and for each UE 3.
 以下、OLT4の構成を説明する。OLT4は、無線情報抽出部11と、リソース変換部12と、番号抽出部13と、GPS抽出部14と、時刻抽出部15と、時刻推定部16と、MPCP部17と、時刻変換部18と、PONスケジューラ19と、多重部(以下、MUXとする)20と、光送受信部21とで構成されている。以下、これらの構成要素について説明する。 The configuration of the OLT 4 will be described below. The OLT 4 includes a wireless information extraction unit 11, a resource conversion unit 12, a number extraction unit 13, a GPS extraction unit 14, a time extraction unit 15, a time estimation unit 16, an MPCP unit 17, and a time conversion unit 18. , PON scheduler 19, multiplexer (hereinafter referred to as MUX) 20, and optical transmitter / receiver 21. Hereinafter, these components will be described.
 無線情報抽出部11は、親局装置1からの下りデータから、無線上りスケジューリング情報を抽出する。無線上りスケジューリング情報には、割当リソース情報と、無線フレーム番号と、サブフレーム番号とが、含まれる。 The radio information extraction unit 11 extracts radio uplink scheduling information from the downlink data from the master station device 1. The uplink radio scheduling information includes allocation resource information, a radio frame number, and a subframe number.
 リソース変換部12は、無線情報抽出部11によって抽出された無線上りスケジューリング情報に含まれる割当リソース情報からUE3毎の無線上りデータ量を検索し、UE3の上りデータを受信するONU5毎に積算したデータ量を算出し、光リソース情報としてPONスケジューラ19に通知する。 The resource conversion unit 12 searches the amount of uplink data for each UE 3 from the allocation resource information included in the uplink radio scheduling information extracted by the radio information extraction unit 11, and accumulates the data for each ONU 5 that receives uplink data of the UE 3 The amount is calculated and notified to the PON scheduler 19 as light resource information.
 番号抽出部13は、無線情報抽出部11によって抽出された無線上りスケジューリング情報から、無線フレーム番号とサブフレーム番号とを抽出して、時刻推定部16に対して出力する。 The number extraction unit 13 extracts the radio frame number and the subframe number from the radio uplink scheduling information extracted by the radio information extraction unit 11 and outputs the radio frame number and the subframe number to the time estimation unit 16.
 GPS抽出部14は、外部に設けられたGPS受信器7からの1PPS,ToDに基づいて、絶対時刻を管理する。 The GPS extraction unit 14 manages an absolute time based on 1 PPS and ToD from the GPS receiver 7 provided outside.
 時刻抽出部15は、ONU5からの上りデータから、当該上りデータに多重されたサブフレーム先頭通知フレームを抽出する。サブフレーム先頭通知フレームには、無線フレーム番号、サブフレーム番号、サブフレーム先頭時刻が含まれる。ここで、サブフレーム先頭時刻とは、ONU5が、子局装置2から、上りデータに含まれるSUBFRAME.indicationフレームを受信した受信時刻を示す。SUBFRAME.indicationフレームとは、UE3がサブフレームを送信する送信タイミング情報を示す情報を含む。 The time extraction unit 15 extracts, from the upstream data from the ONU 5, the subframe top notification frame multiplexed into the upstream data. The subframe start notification frame includes a radio frame number, a subframe number, and a subframe start time. Here, the subframe start time means that the ONU 5 receives SUBFRAME. Indicates the reception time at which the indication frame was received. SUBFRAME. The indication frame includes information indicating transmission timing information for the UE 3 to transmit a subframe.
 時刻推定部16は、番号抽出部13によって抽出された無線フレーム番号及びサブフレーム番号が示す無線データがONU5で受信される受信時刻を絶対時刻で推定し、ONU受信時刻として出力する。具体的には、時刻推定部16には、時刻抽出部15から、ONU5からのサブフレーム先頭通知フレームに含まれる無線フレーム番号、サブフレーム番号、サブフレーム先頭時刻が入力される。また、時刻推定部16には、システム設定値である1サブフレームの時間長が予め記憶されている。さらに、時刻推定部16には、番号抽出部13によって抽出された無線フレーム番号及びサブフレーム番号が入力される。時刻推定部16は、番号抽出部13によって抽出された無線フレーム番号及びサブフレーム番号と、先頭通知フレームに含まれる無線フレーム番号及びサブフレーム番号とを照合することにより、先頭通知フレームに含まれるサブフレーム先頭時刻の中から、番号抽出部13によって抽出された無線フレーム番号及びサブフレーム番号に対応するサブフレーム先頭時刻を検索して求め、ONU受信時刻として出力する。 The time estimation unit 16 estimates the reception time at which the wireless data indicated by the wireless frame number and the subframe number extracted by the number extraction unit 13 is received by the ONU 5 as an absolute time, and outputs it as the ONU reception time. Specifically, the time estimation unit 16 receives, from the time extraction unit 15, the radio frame number, the subframe number, and the subframe start time included in the subframe start notification frame from the ONU 5. Further, in the time estimation unit 16, a time length of one subframe, which is a system setting value, is stored in advance. Further, the radio frame number and the subframe number extracted by the number extraction unit 13 are input to the time estimation unit 16. The time estimation unit 16 collates the radio frame number and the subframe number extracted by the number extraction unit 13 with the radio frame number and the subframe number included in the top notification frame to obtain the sub From the frame start time, the subframe start time corresponding to the wireless frame number and the subframe number extracted by the number extraction unit 13 is retrieved and obtained, and is output as the ONU reception time.
 なお、番号抽出部13、時刻抽出部15、および、時刻推定部16は、時刻抽出部15が抽出した受信時刻に基づいて、無線上りスケジューリング情報に対応するデータを端末側装置であるONU5が子局装置2から受信する推定受信時刻を算出する推定時刻算出部を構成している。
 また、番号抽出部13は、無線上りスケジューリング情報から、無線フレーム番号及びサブフレーム番号を抽出する第1の番号抽出部を構成している。
 また、時刻抽出部15は、通知フレームとしてのサブフレーム先頭通知フレームから、無線フレーム番号及びサブフレーム番号を抽出する第2の番号抽出部を構成している。
 また、時刻推定部16は、第1の番号抽出部である番号抽出部13で抽出した無線フレーム番号及びサブフレーム番号と第2の番号抽出部である時刻抽出部15で抽出した無線フレーム番号及びサブフレーム番号とを照合することによって、時刻抽出部15によって抽出されたサブフレーム先頭通知フレームに含まれる受信時刻の中から、第1の番号抽出部である番号抽出部13で抽出した無線フレーム番号及びサブフレーム番号に対応する受信時刻を検索し、検索により得られた受信時刻を推定受信時刻であるONU受信時刻として出力する時刻推定部を構成している。
The number extracting unit 13, the time extracting unit 15, and the time estimating unit 16 select the data corresponding to the wireless uplink scheduling information based on the reception time extracted by the time extracting unit 15 as the ONU 5 serving as the terminal device. The estimated time calculation unit configured to calculate the estimated reception time received from the station device 2 is configured.
Also, the number extraction unit 13 constitutes a first number extraction unit that extracts a radio frame number and a subframe number from the radio uplink scheduling information.
Further, the time extraction unit 15 configures a second number extraction unit that extracts a radio frame number and a subframe number from a subframe top notification frame as a notification frame.
In addition, the time estimation unit 16 includes the radio frame number and subframe number extracted by the number extraction unit 13 which is a first number extraction unit, the radio frame number extracted by the time extraction unit 15 which is a second number extraction unit, The wireless frame number extracted by the number extraction unit 13 which is the first number extraction unit from among the reception times included in the subframe top notification frame extracted by the time extraction unit 15 by collating with the subframe number And the time estimation part which searches the reception time corresponding to a sub-frame number, and outputs the reception time obtained by the search as ONU reception time which is estimated reception time is comprised.
 MPCP部17は、OLT4及びONU5が構成するPONシステムのシステム管理時刻であるLocal Timeを管理する。また、MPCP部17は、後述のPONスケジューラ19からの光上りスケジューリング情報に基づいて、ONU5へのリソース割当情報および送信許可タイミングを通知するための制御フレーム(以下、Gateフレームとする)を生成する。 The MPCP unit 17 manages Local Time, which is a system management time of the PON system configured by the OLT 4 and the ONU 5. Also, the MPCP unit 17 generates a control frame (hereinafter referred to as a Gate frame) for notifying resource allocation information to the ONU 5 and transmission permission timing based on optical uplink scheduling information from the PON scheduler 19 described later. .
 時刻変換部18は、MPCP部17が管理する現在のLocal TimeとGPS抽出部14からの絶対時刻とに基づいて、時刻推定部16からの絶対時刻で表現されたONU受信時刻を、Local Timeに変換して、ONUデータ受信タイミングとして出力する。すなわち、ONUデータ受信タイミングは、Local Timeで表現されたONU受信時刻である。時刻推定部16から出力されたONU受信時刻は、絶対時刻で表現されているため、そのままでは、PONスケジューラ19で使用することができない。PONスケジューラ19で使用できるデータは、PONシステムのシステム管理時刻であるLocal Timeで表現されている必要がある、そのため、時刻変換部18では、ONU受信時刻を、絶対時刻からLocal Time時刻へ変換する処理を行っている。 The time conversion unit 18 sets the ONU reception time represented by the absolute time from the time estimation unit 16 to the Local Time based on the current Local Time managed by the MPCP unit 17 and the absolute time from the GPS extraction unit 14. It converts and outputs as ONU data reception timing. That is, the ONU data reception timing is the ONU reception time represented by Local Time. The ONU reception time output from the time estimation unit 16 is expressed as an absolute time, and therefore can not be used by the PON scheduler 19 as it is. The data that can be used by the PON scheduler 19 needs to be expressed in Local Time, which is the system management time of the PON system, so the time conversion unit 18 converts ONU reception time from absolute time to Local Time time. Processing is in progress.
 PONスケジューラ19は、リソース変換部12からの光リソース情報と時刻変換部18からのONUデータ受信タイミングとから、各ONU5への割り当てるリソースをスケジューリングして、光上りスケジューリング情報として出力する。なお、PONスケジューラ19は、推定受信時刻を示すONUデータ受信タイミングと無線上りスケジューリング情報とに基づいて、端末側装置であるONU5から局側装置2へデータ送信を行うための光上りスケジューリング情報を生成するスケジューリング部を構成している。 The PON scheduler 19 schedules a resource to be allocated to each ONU 5 from the optical resource information from the resource conversion unit 12 and the ONU data reception timing from the time conversion unit 18 and outputs it as optical uplink scheduling information. The PON scheduler 19 generates optical uplink scheduling information for transmitting data from the terminal device 5 ONU 5 to the station device 2 based on the ONU data reception timing indicating the estimated reception time and the wireless uplink scheduling information. Configuring a scheduling unit.
 MUX20は、MPCP部17で生成されたGateフレームを、下りデータに多重する。 The MUX 20 multiplexes the Gate frame generated by the MPCP unit 17 into downlink data.
 光送受信部21は、ONU5からの上りデータを受信して、時刻抽出部15と親局装置1とに対して出力する。また、光送受信部21は、MUX20で多重された下りデータとGateフレームとを、ONU5に対して出力する。 The optical transmission / reception unit 21 receives uplink data from the ONU 5 and outputs the data to the time extraction unit 15 and the master station device 1. Also, the optical transmission / reception unit 21 outputs the downstream data and the Gate frame multiplexed by the MUX 20 to the ONU 5.
 なお、MPCP部17、MUX20、及び、光送受信部21は、光上りスケジューリング情報を端末側装置であるONU5に通知する通知部を構成している。 The MPCP unit 17, the MUX 20, and the optical transmission / reception unit 21 constitute a notification unit that notifies the ONU 5 which is the terminal side apparatus of the optical uplink scheduling information.
 次に、ONU5の構成を説明する。ONU5は、番号抽出部22と、GPS抽出部23と、時刻検出部24と、フレーム生成部25と、MPCP部26と、送信制御部27と、光送受信部28と、多重部(以下、MUX)29とで構成されている。 Next, the configuration of the ONU 5 will be described. The ONU 5 includes a number extraction unit 22, a GPS extraction unit 23, a time detection unit 24, a frame generation unit 25, an MPCP unit 26, a transmission control unit 27, an optical transmission / reception unit 28, and a multiplexing unit (hereinafter, MUX And 29).
 番号抽出部22は、子局装置2からの上りデータから、SUBFRAME.indicationフレームを抽出し、SUBFRAME.indicationフレームに含まれる無線フレーム番号およびサブフレーム番号を取得する。取得した無線フレーム番号およびサブフレーム番号は、フレーム生成部25に対して出力される。また、番号抽出部22は、SUBFRAME.indicationフレームの受信を示すフレーム受信トリガを生成する。生成されたフレーム受信トリガは、時刻検出部24に対して出力される。 The number extraction unit 22 uses SUBRAM. Indication frame is extracted, SUBFRAME. The radio frame number and the subframe number included in the indication frame are acquired. The acquired radio frame number and subframe number are output to the frame generation unit 25. In addition, the number extraction unit 22 sets the SUBFRAME. Generate a frame reception trigger indicating reception of an indication frame. The generated frame reception trigger is output to the time detection unit 24.
 GPS抽出部23は、外部に設けられたGPS受信器7からの1PPS,ToDに基づいて、絶対時刻を管理する。 The GPS extraction unit 23 manages an absolute time based on 1 PPS and ToD from the GPS receiver 7 provided outside.
 時刻検出部24は、番号抽出部22からのフレーム受信トリガとGPS抽出部23からの絶対時刻とから、ONU5がSUBFRAME.indicationフレームを受信した受信時刻を絶対時刻で検出して、サブフレーム先頭時刻として出力する。 The time detection unit 24 uses the frame reception trigger from the number extraction unit 22 and the absolute time from the GPS extraction unit 23 to determine that the ONU 5 is a SUBFRAME. The reception time at which the indication frame is received is detected as an absolute time, and is output as the subframe start time.
 番号抽出部22および時刻検出部24は、端末であるUE3が無線データを送信する送信タイミングを示す無線データ送信タイミング情報を、子局装置2から受信して、無線データ送信タイミング情報を受信した受信時刻を検出する受信時刻検出部を構成している。 The number extraction unit 22 and the time detection unit 24 receive the wireless data transmission timing information indicating the transmission timing at which the terminal UE 3 transmits wireless data from the slave station apparatus 2 and receiving the wireless data transmission timing information A reception time detection unit that detects a time is configured.
 フレーム生成部25は、番号抽出部22で取得された無線フレーム番号及びサブフレーム番号と、時刻検出部24で検出されたサブフレーム先頭時刻とを含む、サブフレーム先頭通知フレームを生成する。 The frame generation unit 25 generates a subframe top notification frame including the radio frame number and subframe number obtained by the number extraction unit 22 and the subframe start time detected by the time detection unit 24.
 MPCP部26は、光送受信部28がOLT4から受信した下りデータから、Gateフレームを抽出して処理し、Gateフレームに含まれる、送信許可タイミングを示す送信許可信号を出力する。 The MPCP unit 26 extracts and processes a Gate frame from the downlink data received from the OLT 4 by the light transmitting / receiving unit 28, and outputs a transmission permission signal indicating transmission permission timing included in the Gate frame.
 送信制御部27は、MPCP部26からの送信許可信号の送信許可タイミングに従って、上りデータ及びサブフレーム先頭通知フレームの送信の制御を行う。 The transmission control unit 27 controls transmission of uplink data and a subframe top notification frame in accordance with the transmission permission timing of the transmission permission signal from the MPCP unit 26.
 光送受信部28は、送信制御部27の制御により、上りデータ及びサブフレーム先頭通知フレームをOLT4に送信する。また、光送受信部28は、OLT4からの下りデータを受信して、MPCP部26および子局装置2に対して出力する。 The optical transmission / reception unit 28 transmits the upstream data and the subframe top notification frame to the OLT 4 under the control of the transmission control unit 27. The optical transmission / reception unit 28 also receives downlink data from the OLT 4 and outputs the downlink data to the MPCP unit 26 and the slave station device 2.
 なお、フレーム生成部25、送信制御部27、及び、光送受信部28は、ONU5の受信時刻を局側装置であるOLT4に通知する通知フレームとしてのサブフレーム先頭通知フレームを送信する送信部を構成している。 The frame generation unit 25, the transmission control unit 27, and the optical transmission / reception unit 28 constitute a transmission unit for transmitting a subframe top notification frame as a notification frame for notifying the OLT 4 as the station apparatus of the reception time of the ONU 5 doing.
 MUX29は、フレーム生成部25で生成されたサブフレーム先頭通知フレームを、上りデータに多重して、送信制御部27に出力する。 The MUX 29 multiplexes the subframe top notification frame generated by the frame generation unit 25 with uplink data, and outputs the uplink data to the transmission control unit 27.
 次に、動作について説明する。 Next, the operation will be described.
 初めに、ONU5における、子局装置2の無線フレーム番号及びサブフレーム番号とサブフレーム先頭時刻とを把握する処理について説明する。図5に、サブフレーム先頭時刻の把握処理のフローの例を示す。 First, a process of grasping the radio frame number and subframe number of the slave station device 2 and the subframe start time in the ONU 5 will be described. FIG. 5 shows an example of the flow of processing for grasping the subframe start time.
 図5において、まず、ステップS1について説明する。ONU5は、子局装置2から、上りデータを受信する。上りデータには、主信号データとSUBFRAME.indicationフレームとが含まれている。ONU5は、子局装置2から上りデータを受信する際に、サブフレームの先頭毎に、SUBFRAME.indicationフレームを受信する。従って、SUBFRAME.indicationフレームの受信時刻は、サブフレームの先頭を受信した時刻を示す。そのため、ここでは、当該時刻を、サブフレーム先頭時刻と呼ぶ。ONU5で受信された上りデータは、番号抽出部22に転送される。ステップS1では、番号抽出部22が、ONU5がSUBFRAME.indicationフレームを受信したことを示すフレーム受信トリガを生成する。フレーム受信トリガは、時刻検出部24に対して出力される。 First, step S1 will be described with reference to FIG. The ONU 5 receives uplink data from the slave station device 2. Upstream data includes main signal data and SUBFRAME. and an indication frame. When the ONU 5 receives uplink data from the slave station device 2, the SUB FRAME. Receive indication frame. Therefore, SUBFRAME. The reception time of the indication frame indicates the time when the beginning of the subframe is received. Therefore, here, the time is referred to as a subframe start time. Uplink data received by the ONU 5 is transferred to the number extraction unit 22. In step S1, the number extraction unit 22 sets the ONU 5 to the SUBFRAME. A frame reception trigger is generated to indicate that an indication frame has been received. The frame reception trigger is output to the time detection unit 24.
 次に、ステップS2について説明する。ONU5では、GPS受信器7などの外部装置もしくは上位装置から、GPS信号(1PPS,ToD)を受信しており、GPS抽出部23にて、GPS信号を用いて絶対時刻を把握している。この絶対時刻は、時刻検出部24に通知されている。ステップS2では、時刻検出部24が、番号抽出部22からのフレーム受信トリガと、GPS抽出部23からの絶対時刻とを用いて、SUBFRAME.indicationフレームの受信時刻を検出し、サブフレーム先頭時刻として、フレーム生成部25へと通知する。 Next, step S2 will be described. The ONU 5 receives a GPS signal (1 PPS, ToD) from an external device such as the GPS receiver 7 or a host device, and the GPS extraction unit 23 grasps an absolute time using the GPS signal. The absolute time is notified to the time detection unit 24. In step S2, the time detection unit 24 uses the frame reception trigger from the number extraction unit 22 and the absolute time from the GPS extraction unit 23 to set the SUBFRAME. The reception time of the indication frame is detected and notified to the frame generation unit 25 as the subframe start time.
 ステップS3では、番号抽出部22が、上りデータから、無線フレーム番号およびサブフレーム番号を抽出する。抽出された無線フレーム番号及びサブフレーム番号は、フレーム生成部25へと通知される。 In step S3, the number extraction unit 22 extracts the radio frame number and the subframe number from the uplink data. The extracted radio frame number and subframe number are notified to the frame generation unit 25.
 ステップS4では、フレーム生成部25が、番号抽出部22で抽出された無線フレーム番号及びサブフレーム番号と、時刻検出部24で検出されたサブフレーム先頭時刻とを用いて、サブフレーム先頭通知フレームを生成する。従って、サブフレーム先頭通知フレームには、無線フレーム番号、サブフレーム番号、及び、サブフレーム先頭時刻が含まれる。 In step S4, the frame generation unit 25 uses the radio frame number and subframe number extracted by the number extraction unit 22 and the subframe start time detected by the time detection unit 24 to generate a subframe start notification frame. Generate Therefore, the subframe start notification frame includes the radio frame number, the subframe number, and the subframe start time.
 ステップS5では、MUX29で、サブフレーム先頭通知フレームが上りデータに多重され、送信制御部27に送信される。一方、MPCP部26が、OLT4から送信されてきたGateフレームに含まれる送信許可信号から送信許可タイミングを抽出する。送信制御部27は、送信許可タイミングに従って、多重された上りデータ及びサブフレーム先頭通知フレームをOLT4に送信する。 In step S5, in the MUX 29, the subframe top notification frame is multiplexed with the uplink data, and transmitted to the transmission control unit 27. On the other hand, the MPCP unit 26 extracts transmission permission timing from the transmission permission signal included in the Gate frame transmitted from the OLT 4. The transmission control unit 27 transmits the multiplexed uplink data and the subframe top notification frame to the OLT 4 in accordance with the transmission permission timing.
 続いて、OLT4でのサブフレーム先頭通知フレームからサブフレーム先頭時刻を把握する処理について説明する。図6に、サブフレーム先頭時刻の把握処理のフローの例を示す。 Subsequently, a process of grasping the subframe top time from the subframe top notification frame in the OLT 4 will be described. FIG. 6 shows an example of the flow of processing for grasping the subframe start time.
 図6において、ステップS11では、OLT4において、ONU5から、上りデータに多重されたサブフレーム先頭通知フレームを受信する。サブフレーム先頭通知フレームは、時刻抽出部15に入力される。時刻抽出部15では、サブフレーム先頭通知フレームを抽出する。 In FIG. 6, in step S11, the OLT 4 receives, from the ONU 5, a subframe top notification frame multiplexed into upstream data. The subframe top notification frame is input to the time extraction unit 15. The time extraction unit 15 extracts a subframe top notification frame.
 ステップS12では、時刻抽出部15が、サブフレーム先頭通知フレームに格納された無線フレーム番号、サブフレーム番号、及び、サブフレーム先頭時刻を抽出して、時刻推定部16に通知する。 In step S12, the time extraction unit 15 extracts the radio frame number, the subframe number, and the subframe start time stored in the subframe start notification frame, and notifies the time estimation unit 16 of them.
 ステップS13では、時刻推定部16が、OLT4の無線フレーム番号及びサブフレーム番号に対応するサブフレーム先頭時刻を求め、ONU受信時刻を更新する。具体的には、時刻推定部16は、番号抽出部13で抽出した無線フレーム番号及びサブフレーム番号と時刻抽出部15で抽出した無線フレーム番号及びサブフレーム番号とを照合することによって、時刻抽出部15で抽出したサブフレーム先頭時刻の中から、番号抽出部13で抽出した無線フレーム番号及びサブフレーム番号に対応するサブフレーム先頭時刻を検索する。時刻推定部16は、当該検索で得られたサブフレーム先頭時刻を、ONU5における受信時刻の推定値として出力する。ここでは、当該推定値を、ONU受信時刻と呼ぶ。 In step S13, the time estimation unit 16 obtains the subframe start time corresponding to the radio frame number and the subframe number of the OLT 4 and updates the ONU reception time. Specifically, the time estimation unit 16 collates the radio frame number and the subframe number extracted by the number extraction unit 13 with the radio frame number and the subframe number extracted by the time extraction unit 15 to obtain a time extraction unit. The subframe start time corresponding to the radio frame number and subframe number extracted by the number extraction unit 13 is searched from among the subframe start times extracted at 15. The time estimation unit 16 outputs the subframe start time obtained by the search as an estimated value of the reception time in the ONU 5. Here, the estimated value is referred to as ONU reception time.
 ステップS11~S13の処理を、OLT4に接続された各ONU5ごとに実施する。 The processes in steps S11 to S13 are performed for each ONU 5 connected to the OLT 4.
 これにより、子局装置2からONU5に到着するサブフレーム先頭時刻を、ONU5毎に、OLT4にて正確に把握することが可能となる。このサブフレーム先頭時刻は、ONU5において、フレーム受信トリガによって得た値であるため、実測された受信時刻である。そのため、子局装置2の処理遅延、ONU5の処理遅延、子局装置2とONU5との間の伝送遅延に起因するずれが含まれている。当該ずれが含まれた受信時刻を、フレーム受信トリガによって得ることで、正確な受信時刻が取得できる。そうして得た正確な受信時刻をOLT4に通知することで、OLT4においても、正確な受信時刻を把握することができる。 As a result, it becomes possible for the OLT 4 to accurately grasp, for each ONU 5, the subframe start time that arrives at the ONU 5 from the slave station device 2. This sub-frame start time is a value obtained by the frame reception trigger in the ONU 5 and thus is an actually measured reception time. Therefore, the processing delay of the slave station 2, the processing delay of the ONU 5, and the deviation due to the transmission delay between the slave station 2 and the ONU 5 are included. The accurate reception time can be acquired by obtaining the reception time including the deviation by the frame reception trigger. By notifying the OLT 4 of the accurate reception time thus obtained, the OLT 4 can also grasp the accurate reception time.
 次に、上記の無線フレーム・サブフレーム先頭時刻を用いたONU5への光上りスケジューリングの処理の流れについて説明する。図7に、サブフレーム先頭時刻を用いたONU5への光上りスケジューリング処理のフローの例を示す。 Next, the flow of processing of optical uplink scheduling to the ONU 5 using the above-mentioned wireless frame / subframe start time will be described. FIG. 7 shows an example of the flow of the optical uplink scheduling process for the ONU 5 using the subframe start time.
 まず、親局装置1から、無線上りスケジューリング情報を含む下りデータがOLT4に送信される。 First, downlink data including radio uplink scheduling information is transmitted from the master station device 1 to the OLT 4.
 ステップS21では、OLT4で受信した下りデータは、無線情報抽出部11に入力される。無線情報抽出部11は、下りデータから、無線主信号と無線上りスケジューリング情報とを抽出する。無線上りスケジューリング情報には、図2に示すように、子局装置2毎、UE3毎の、子局受信タイミング情報として、無線フレーム番号とサブフレーム番号が格納され、割当リソース情報として、RIV、MCSが格納されている。なお、図2ではRIVはRBAと記載され、MCSはM#1,M#2と記載されている。抽出した無線上りスケジューリング情報は、リソース変換部12と番号抽出部13にそれぞれ転送される。番号抽出部13では、無線上りスケジューリング情報から、子局装置2毎、UE3毎の、無線フレーム番号およびサブフレーム番号を抽出する。抽出した無線フレーム番号およびサブフレーム番号は時刻推定部16に転送される。 In step S21, the downlink data received by the OLT 4 is input to the wireless information extraction unit 11. The radio information extraction unit 11 extracts a radio main signal and radio uplink scheduling information from the downlink data. The radio uplink scheduling information stores radio frame numbers and subframe numbers as slave station reception timing information for each slave station apparatus 2 and for each UE 3 as shown in FIG. 2, and RIV, MCS as allocation resource information. Is stored. In FIG. 2, RIV is described as RBA, and MCS is described as M # 1 and M # 2. The extracted radio uplink scheduling information is transferred to the resource conversion unit 12 and the number extraction unit 13 respectively. The number extraction unit 13 extracts the radio frame number and the subframe number for each mobile station apparatus 2 and for each UE 3 from the radio uplink scheduling information. The extracted radio frame number and subframe number are transferred to the time estimation unit 16.
 ステップS22では、リソース変換部12が、無線上りスケジューリング情報から、UE3毎の割当リソース情報を抽出し、抽出したUE3毎の割当リソース情報から上りデータ量を算出する。算出された上りデータ量は、PONスケジューラ19へと通知される。 In step S22, the resource conversion unit 12 extracts allocation resource information for each UE 3 from the uplink radio scheduling information, and calculates an uplink data amount from the extracted allocation resource information for each UE 3. The calculated amount of uplink data is notified to the PON scheduler 19.
 ステップS23では、時刻推定部16が、ONU5からのサブフレーム先頭通知フレームに含まれる、無線フレーム番号、サブフレーム番号、サブフレーム先頭時刻と、システム設定値である1サブフレームの時間長とを用いて、サブフレーム先頭通知フレームに含まれるサブフレーム先頭時刻の中から、番号抽出部13によって抽出された無線フレーム番号及びサブフレーム番号に対応するサブフレーム先頭時刻を求め、当該サブフレーム先頭時刻を時刻順に並び替え、ONU受信時刻として、時刻変換部18に対して出力する。 In step S23, the time estimation unit 16 uses the radio frame number, the subframe number, the subframe start time, and the time length of one subframe which is a system setting value, included in the subframe start notification frame from the ONU 5. The subframe start time corresponding to the radio frame number and the subframe number extracted by the number extraction unit 13 is determined from the subframe start times included in the subframe start notification frame, and the subframe start time is determined as the time. It rearranges in order, and outputs it to the time conversion part 18 as ONU reception time.
 ステップS24では、時刻変換部18が、MPCP部17が管理する現在のLocal Timeと、GPS抽出部14からの絶対時刻とを用いて、ONU受信時刻を絶対時間表現からLocal Time表現へと変換することで、ONUデータ受信タイミングを得る。ONU受信タイミングは、PONスケジューラ19に対して出力される。 In step S24, the time conversion unit 18 converts the ONU reception time from an absolute time expression to a local time expression using the current Local Time managed by the MPCP unit 17 and the absolute time from the GPS extraction unit 14. Thus, the ONU data reception timing is obtained. The ONU reception timing is output to the PON scheduler 19.
 次に、ステップS25~S29の処理を実行する。ステップS25~S29の処理において、PONスケジューラ19では、子局装置2毎、UE3毎の、ONUデータ受信タイミングと、光リソース情報に含まれる上りデータ量とから、ONU5毎の光上りスケジューリングを行い、MPCP部17へと通知する。このとき、ONUデータ受信タイミングには、OLT4-ONU5間の往復遅延時間によるずれが含まれていないため、PONスケジューラ19は、OLT4-ONU5間の往復遅延時間も加味して、光上りスケジューリングを行うことが、より望ましい。MPCP部17では、この光上りスケジューリング情報を基に、Gateフレームを生成し、ONU5へと通知する。Gateフレームには、ONU5がOLT4に対して上りデータを送信することを許可する送信許可タイミングを示す送信許可信号が含まれている。 Next, the processes of steps S25 to S29 are performed. In the processes of steps S25 to S29, the PON scheduler 19 performs optical uplink scheduling for each ONU 5 from the ONU data reception timing for each slave station apparatus 2 and for each UE 3 and the amount of uplink data included in the optical resource information, It notifies the MPCP unit 17. At this time, since the ONU data reception timing does not include the deviation due to the round trip delay time between the OLT 4 and the ONU 5, the PON scheduler 19 performs the optical uplink scheduling in consideration of the round trip delay time between the OLT 4 and the ONU 5 as well. Is more desirable. The MPCP unit 17 generates a Gate frame based on the optical uplink scheduling information, and notifies the ONU 5 of it. The Gate frame includes a transmission permission signal indicating a transmission permission timing for permitting the ONU 5 to transmit uplink data to the OLT 4.
 以下、ステップS25~S29について説明する。ステップS25~S29の処理は、予め設定された割当周期ごとに、繰り返し、実行される。 Hereinafter, steps S25 to S29 will be described. The processes of steps S25 to S29 are repeatedly performed for each preset allocation cycle.
 ステップS25では、PONスケジューラ19が、システム設定値に従い、子局装置2が同時に受信するUE3からの全データを格納して、ONU5に送信するフレーム数を求め、N[i]個とする。 In step S25, the PON scheduler 19 stores all data from the UE 3 simultaneously received by the slave station device 2 according to the system setting value, obtains the number of frames to be transmitted to the ONU 5, and sets it as N [i].
 ステップS26では、PONスケジューラ19が、システム設計値と、UE3毎のデータ量とから、N[i]個のフレームのフレーム長を求める。 In step S26, the PON scheduler 19 obtains the frame length of N [i] frames from the system design value and the amount of data for each UE3.
 ステップS27では、ONU5のRTTと外部ネットワーク装置構成情報に従い、データ受信時刻を、子局装置2のN[i]個のフレームのフレーム送信開始時刻に変換する。 In step S27, the data reception time is converted to the frame transmission start time of N [i] frames of the slave station apparatus 2 according to the RTT of the ONU 5 and the external network apparatus configuration information.
 PONスケジューラ19は、ステップS25~S27の処理を、OLT4に接続された各ONU5毎に実行する。そうして、すべてのONU5に対して、ステップS25~S27の処理が終了したら、ステップS28に進む。 The PON scheduler 19 executes the processing of steps S 25 to S 27 for each ONU 5 connected to the OLT 4. Then, when the process of steps S25 to S27 is completed for all ONUs 5, the process proceeds to step S28.
 ステップS28では、PONスケジューラ19が、N[i]個の総数の送信開始時刻とフレーム長とに基づき、PON区間で生じるオーバーヘッドも加算して、全てのONU5の送信許可を割り当てる。 In step S28, the PON scheduler 19 adds the overhead generated in the PON section based on the total number of transmission start times of N [i] and the frame length, and assigns the transmission permission of all ONUs 5.
 ステップS29では、PONスケジューラ19が、光上りスケジューリング情報とは独立に発生する上りデータのために、余剰帯域を全ONU5に割り当てる。 In step S29, the PON scheduler 19 allocates a surplus bandwidth to all ONUs 5 for uplink data generated independently of the optical uplink scheduling information.
 次に、実施の形態1を実現するOLT4及びONU5のハードウェア構成例を、図8及び図9にそれぞれ示す。図1に示すOLT4及びONU5の各部の機能は処理回路によって実現される。処理回路が専用のハードウェアである場合、処理回路は、例えば単一回路、複合回路、プログラム化したプロセッサ、並列プログラム化したプロセッサ、ASIC、FPGA、またはこれらを組み合わせたものが該当する。 Next, hardware configuration examples of the OLT 4 and the ONU 5 for realizing the first embodiment are shown in FIG. 8 and FIG. 9, respectively. The functions of the respective units of the OLT 4 and the ONU 5 shown in FIG. 1 are realized by a processing circuit. Where the processing circuit is dedicated hardware, the processing circuit may be, for example, a single circuit, a complex circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.
 また、実施の形態1を実現するOLT4及びONU5ハードウェア構成のもう一つの例を、図10及び図11に示す。処理回路がCPUの場合、図1に示すOLT4及びONU5の各部の機能は、ソフトウェア、ファームウェア、またはそれらの組み合わせにより実現される。ソフトウェアやファームウェアはプログラムとして記述され、メモリに格納される。処理回路を構成するプロセッサは、メモリに記録されたプログラムを読み出して実行することにより、前述の各部の機能を実現する。 Further, another example of the hardware configuration of the OLT 4 and the ONU 5 for realizing the first embodiment is shown in FIG. 10 and FIG. When the processing circuit is a CPU, the functions of the respective units of the OLT 4 and the ONU 5 shown in FIG. 1 are realized by software, firmware, or a combination thereof. Software and firmware are described as programs and stored in memory. The processor that configures the processing circuit implements the functions of the above-described units by reading and executing the program stored in the memory.
 なお、各機能について、一部を専用のハードウェアで実現し、一部をソフトウェアまたはファームウェアで実現するようにしてもよい。また、OLT4及びONU5の構成も図8~図11を組み合わせてもよい。このように、処理回路は、ハードウェア、ソフトウェア、ファームウェア、またはこれらの組み合わせによって、前述の各機能を実現することができる。 The respective functions may be partially realized by dedicated hardware and partially realized by software or firmware. Further, the configurations of the OLT 4 and the ONU 5 may be combined with FIGS. In this way, the processing circuit can realize the above-described functions by hardware, software, firmware, or a combination thereof.
 上述したように、実施の形態1においては、ONU5でのSUBFRAME.indicationフレームの受信、および、当該フレームの受信時刻のOLT4への通知により、親局装置1が管理する、UE3毎、子局装置2毎の、無線上りスケジューリング情報と、PONにおける光上りスケジューリング情報とを正確に合致させることで、ONU5での無線データ蓄積時間を減らしたリソース割当が実施可能となり、上り遅延時間が低減される。 As described above, in the first embodiment, SUBFRAME. The radio uplink scheduling information for each UE 3 and each slave station 2 managed by the master station device 1 by the reception of the indication frame and the notification of the reception time of the frame to the OLT 4 and the optical uplink scheduling information in the PON By accurately matching the above, resource allocation with reduced wireless data storage time at the ONU 5 can be implemented, and the upstream delay time is reduced.
 以上のように、実施の形態1に係る光通信システムにおいては、端末側装置であるONU5が、UE3が無線データを送信する送信タイミングを示す無線データ送信タイミング情報であるSUBFRAME.indicationフレームを子局装置2から受信して、当該フレームを受信した受信時刻を検出する番号抽出部22及び時刻検出部24と、当該受信時刻を局側装置であるOLT4に通知するサブフレーム先頭通知フレームを生成して送信する送信部(25,27,及び,28)とを備えている。 As described above, in the optical communication system according to the first embodiment, the terminal side device ONU 5 is a wireless data transmission timing information indicating the transmission timing at which the UE 3 transmits wireless data. Indication frame is received from the slave station device 2, and the number extraction unit 22 and the time detection unit 24 that detect the reception time when the frame is received, and subframe start notification that notifies the OLT 4 that is the station side device And a transmitter (25, 27 and 28) for generating and transmitting a frame.
 また、局側装置であるOLT4は、親局装置1が管理する無線上りスケジューリング情報を抽出する無線情報抽出部11と、送信部(25,27,及び,28)が送信するサブフレーム先頭通知フレームから受信時刻を抽出する時刻抽出部15と、時刻抽出部15が抽出した受信時刻に基づいて、無線上りスケジューリング情報に対応する無線データをONU5が子局装置2から受信する受信時刻の推定値を算出する推定時刻算出部(13,15,及び,16)と、受信時刻の推定値と無線上りスケジューリング情報とに基づいて、ONU5からOLT4へのデータ送信のための光上りスケジューリング情報を生成するPONスケジューラ19と、光上りスケジューリング情報をONU5に通知する通知部(17,20,及び,21)とを備えている。 Also, the OLT 4, which is a station-side device, transmits a radio information extraction unit 11 that extracts radio uplink scheduling information managed by the parent station device 1, and a subframe top notification frame that is transmitted by the transmission units (25, 27 and 28). Based on the reception time extracted by the reception time extracted by the time extraction unit 15, the estimated value of the reception time at which the ONU 5 receives the wireless data corresponding to the wireless uplink scheduling information from the slave station apparatus 2 PON for generating optical uplink scheduling information for data transmission from ONU 5 to OLT 4 based on the estimated time calculation unit (13, 15, and 16) to be calculated and the estimated value of reception time and wireless uplink scheduling information A scheduler 19 and a notification unit (17, 20, and 21) for notifying the ONU 5 of optical uplink scheduling information; Eteiru.
 こうして、実施の形態1では、ONU5でSUBFRAME.indicationフレームを受信すること、および、当該フレームの受信時刻をOLT4へ通知することにより、親局装置1、子局装置2、ONU5、OLT4における処理遅延、および、子局装置2-ONU5間、親局装置1-OLT4間の、伝送遅延に起因するずれを含む、ONU5での受信時刻を、OLT4が正確に把握することができる。それにより、ONU5での無線データ蓄積時間を減らすリソース割当が可能となり、親局装置1が管理する、UE3毎、子局装置2毎の、無線上りスケジューリング情報と、PONにおける光上りスケジューリング情報とを正確に合致させることができる。このように、実施の形態1では、無線通信において、ONU5における子局装置2からのデータの受信時刻を正確にOLT4が把握することで、上りデータの送信の遅延時間を抑えた、光上りスケジューリングを可能にする。 Thus, in the first embodiment, ONU 5 receives SUBFRAME. By receiving the indication frame and notifying the OLT 4 of the reception time of the frame, processing delay in the master station device 1, slave station device 2, ONU 5, OLT 4 and the slave station devices 2-ONU 5, parent The OLT 4 can accurately grasp the reception time at the ONU 5 including the deviation between the station apparatus 1 and the OLT 4 due to the transmission delay. As a result, resource allocation for reducing the wireless data storage time in the ONU 5 becomes possible, and the wireless uplink scheduling information for each UE 3 and each slave station 2 managed by the master station device 1 and the optical uplink scheduling information in the PON It can be matched exactly. As described above, in the first embodiment, the optical uplink scheduling in which the delay time of transmission of uplink data is suppressed by the OLT 4 accurately grasping the reception time of data from the slave station device 2 in the ONU 5 in wireless communication. Make it possible.
 また、実施の形態1では、無線上りスケジューリング情報が、無線データの無線フレーム番号及びサブフレーム番号を含んでいる。実施の形態1では、推定時刻算出部(13,15,16)が、無線上りスケジューリング情報から、無線フレーム番号及びサブフレーム番号を抽出する番号抽出部13と、サブフレーム先頭通知フレームから、無線フレーム番号及びサブフレーム番号を抽出する第2の番号抽出部としての時刻抽出部15と、番号抽出部13で抽出した無線フレーム番号及びサブフレーム番号と時刻抽出部15で抽出した無線フレーム番号及びサブフレーム番号とを照合することによって、番号抽出部13で抽出した無線フレーム番号及びサブフレーム番号に対応する無線データのONU5における受信時刻を、時刻抽出部15が抽出した受信時刻の中から検索し、当該受信時刻を受信時刻の推定値として算出する時刻推定部16とを有している。このように、実施の形態1では、無線上りスケジューリング情報が、無線データの無線フレーム番号及びサブフレーム番号を含んでいるため、OLT4が、それらの番号に基づいてONU5での受信時刻を検索して、当該受信時刻に基づいてONU受信時刻を推定することができるので、簡単な処理で、容易に且つ正確に、ONU受信時刻を取得することができる。 Also, in the first embodiment, the radio uplink scheduling information includes the radio frame number and the subframe number of the radio data. In the first embodiment, the estimated time calculation unit (13, 15, 16) extracts the radio frame number and the subframe number from the radio uplink scheduling information, the number extraction unit 13 and the subframe start notification frame, the radio frame The time extraction unit 15 as a second number extraction unit for extracting numbers and subframe numbers, the radio frame number and subframe number extracted by the number extraction unit 13, and the radio frame number and subframes extracted by the time extraction unit 15 The reception time at the ONU 5 of the wireless data corresponding to the wireless frame number and the subframe number extracted by the number extraction unit 13 is searched from the reception times extracted by the time extraction unit 15 by collating with the numbers. It has the time estimation part 16 which calculates reception time as an estimated value of reception time. As described above, in the first embodiment, since the wireless uplink scheduling information includes the wireless frame number and the subframe number of the wireless data, the OLT 4 searches for the reception time at the ONU 5 based on those numbers. Since the ONU reception time can be estimated based on the reception time, the ONU reception time can be easily and accurately obtained by simple processing.
 実施の形態2.
 上記の実施の形態1では、親局装置1からの無線上りスケジューリング情報が、無線フレーム番号およびサブフレーム番号を含む場合を示したものであるが、実施の形態2では、無線上りスケジューリング情報が、子局装置2がUE3から無線データを受信する受信時刻の情報を含む場合について説明する。
Second Embodiment
In the first embodiment described above, the case where the wireless uplink scheduling information from the master station apparatus 1 includes the wireless frame number and the subframe number is shown, but in the second embodiment, the wireless uplink scheduling information is The case where the mobile station device 2 includes the information on the reception time when the wireless data is received from the UE 3 will be described.
 図3は、実施の形態2に係る光通信システムの構成を示す構成図である。図3において、ONU5の構成は、図1のONU5の構成と同じであるため、ここでは説明を省略する。一方、OLT4の構成は、図1のOLT4と異なる。具体的に相違点を説明すると、図3においては、図1の番号抽出部13及び時刻推定部16の代わりに、時刻抽出部30及び時刻補正部31が設けられている点である。また、図1の時刻変換部18の代わりに、図3では、時刻変換部18Aが設けられている。図3において、OLT4の他の構成については、図1と同じである。図3において、図1と同じ構成については、同一符号を付して示し、ここでは、その説明を省略する。 FIG. 3 is a block diagram showing the configuration of the optical communication system according to the second embodiment. In FIG. 3, the configuration of the ONU 5 is the same as the configuration of the ONU 5 of FIG. On the other hand, the configuration of the OLT 4 is different from that of the OLT 4 of FIG. Specifically, in FIG. 3, a time extracting unit 30 and a time correcting unit 31 are provided instead of the number extracting unit 13 and the time estimating unit 16 in FIG. Further, in FIG. 3, a time conversion unit 18A is provided instead of the time conversion unit 18 in FIG. 1. In FIG. 3, the other configuration of the OLT 4 is the same as that of FIG. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted here.
 時刻抽出部30は、無線情報抽出部11で抽出された無線上りスケジューリング情報から、子局装置2がUE3から無線データを受信する受信時刻を抽出する。ここでの受信時刻は、絶対時刻で表現されている。以下では、当該受信時刻を、子局受信絶対時刻と呼ぶこととする。 The time extraction unit 30 extracts, from the wireless uplink scheduling information extracted by the wireless information extraction unit 11, the reception time at which the mobile station device 2 receives the wireless data from the UE 3. The reception time here is expressed in absolute time. Hereinafter, the reception time is referred to as a slave station reception absolute time.
 時刻補正部31は、時刻抽出部30で抽出された子局受信絶対時刻と、時刻抽出部15で抽出されたサブフレーム先頭時刻とに基づいて、子局受信絶対時刻を補正してONU受信時刻を得るためのONU受信時刻補正値を算出する。 The time correction unit 31 corrects the slave station reception absolute time based on the slave station reception absolute time extracted by the time extraction unit 30 and the subframe start time extracted by the time extraction unit 15, and the ONU reception time is corrected. Calculate the ONU reception time correction value to obtain.
 時刻変換部18Aには、時刻抽出部30からの子局受信絶対時刻と、OLT4が管理する現在のLocal Timeと、GPS抽出部14からの絶対時刻と、時刻補正部31からの時刻補正値とが入力される。時刻変換部18Aは、ONU受信時刻補正値を用いて子局受信絶対時刻を補正することで、ONU5が子局装置2から無線データを受信する受信時刻の推定値を、ONU受信時刻として求める。次に、時刻変換部18Aは、OLT4が管理する現在のLocal TimeとGPS抽出部14からの絶対時刻とに基づいて、絶対時刻で表現されているONU受信時刻を、Local Timeに変換して、ONUデータ受信タイミングとして出力する。 The time converter 18A includes the slave station reception absolute time from the time extractor 30, the current Local Time managed by the OLT 4, the absolute time from the GPS extractor 14, and the time correction value from the time corrector 31. Is input. The time conversion unit 18A corrects the slave station reception absolute time using the ONU reception time correction value to obtain an estimated value of the reception time when the ONU 5 receives the wireless data from the slave station apparatus 2 as the ONU reception time. Next, based on the current Local Time managed by the OLT 4 and the absolute time from the GPS extraction unit 14, the time conversion unit 18A converts the ONU reception time represented by the absolute time into the Local Time, Output as ONU data reception timing.
 なお、実施の形態2では、時刻抽出部30、時刻補正部31、および、時刻変換部18Aは、時刻抽出部15が抽出した受信時刻に基づいて、無線上りスケジューリング情報に対応するデータを端末側装置であるONU5が子局装置2から受信する推定受信時刻であるONU受信時刻を算出する推定時刻算出部を構成している。
 また、時刻抽出部30は、無線上りスケジューリング情報から子局受信時刻を抽出する子局時刻抽出部を構成している。
 また、時刻補正部31は、時刻抽出部15が抽出した受信時刻と子局受信時刻との差分時間を求め、当該差分時間を時刻補正値として出力する時刻補正部を構成している。
 また、時刻変換部18Aは、時刻補正値に基づいて子局受信時刻を補正することで推定受信時刻を示すONUデータ受信タイミングを算出する時刻算出部を構成している。
In the second embodiment, the time extraction unit 30, the time correction unit 31, and the time conversion unit 18A, based on the reception time extracted by the time extraction unit 15, determine the data corresponding to the radio uplink scheduling information on the terminal side. The estimated time calculation unit is configured to calculate an ONU reception time that is an estimated reception time that the ONU 5 that is a device receives from the slave station apparatus 2.
Further, the time extraction unit 30 configures a slave station time extraction unit that extracts a slave station reception time from the wireless uplink scheduling information.
Further, the time correction unit 31 constitutes a time correction unit which obtains a difference time between the reception time extracted by the time extraction unit 15 and the slave station reception time, and outputs the difference as a time correction value.
In addition, the time conversion unit 18A configures a time calculation unit that calculates ONU data reception timing indicating the estimated reception time by correcting the slave station reception time based on the time correction value.
 次に、動作について説明する。基本的な動作は、上記の実施の形態1と同じである。以下では、時刻抽出部30と時刻補正部31と時刻変換部18Aの動作についてのみ説明する。 Next, the operation will be described. The basic operation is the same as that of the first embodiment described above. Hereinafter, only the operations of the time extraction unit 30, the time correction unit 31, and the time conversion unit 18A will be described.
 次に、実施の形態2に係るONU5への光上りスケジューリング処理について説明する。 Next, the optical uplink scheduling process for the ONU 5 according to the second embodiment will be described.
 親局装置1から、無線上りスケジューリング情報を含む下りデータがOLT4に送信される。OLT4では、受信した下りデータは、無線情報抽出部11に入力される。無線情報抽出部11は、下りデータから、無線主信号と無線上りスケジューリング情報とを抽出する。無線上りスケジューリング情報には、図4に示すように、子局装置2毎、UE3毎の、子局受信タイミングとして、子局装置2でのデータ受信絶対時刻が格納され、また、割当リソースとして、RIV、MCSが格納されている。 Downlink data including radio uplink scheduling information is transmitted from the master station device 1 to the OLT 4. In the OLT 4, the received downlink data is input to the wireless information extraction unit 11. The radio information extraction unit 11 extracts a radio main signal and radio uplink scheduling information from the downlink data. In the wireless uplink scheduling information, as shown in FIG. 4, as the slave station reception timing for each slave station device 2 and for each UE 3, data reception absolute time at the slave station device 2 is stored, and as allocated resources, RIV and MCS are stored.
 無線情報抽出部11で抽出された無線上りスケジューリング情報は、リソース変換部12および時刻抽出部30に対して出力される。時刻抽出部30は、無線上りスケジューリング情報から、子局装置2毎、UE3毎の、子局受信絶対時刻を抽出する。抽出された子局受信絶対時刻は、時刻補正部31に対して出力される。時刻補正部31では、ONU5から通知されたサブフレーム先頭時刻と、1サブフレームの時間長とから、数周期先のサブフレーム先頭時刻を予測する。次に、時刻補正部31は、予測した当該数周期先のサブフレーム先頭時刻と、時刻抽出部30からの子局受信絶対時刻とを比較し、子局受信絶対時刻を超えない最大のサブフレーム先頭時刻と子局受信絶対時刻との差分時間をONU受信時刻補正値として算出する。なお、ここで、1サブフレームの時間長は、システム設定値であり、例えば、LTEの場合、1msである。また、ここでは、数周期先として説明したが、これは、処理における時間的な余裕を持たせるためで、1周期先でもよい。時刻補正部31で算出したONU受信時刻補正値は、時刻変換部18Aへと通知される。 The wireless uplink scheduling information extracted by the wireless information extraction unit 11 is output to the resource conversion unit 12 and the time extraction unit 30. The time extraction unit 30 extracts a slave station reception absolute time for each slave station device 2 and each UE 3 from the wireless uplink scheduling information. The extracted slave station reception absolute time is output to the time correction unit 31. The time correction unit 31 predicts the subframe start time several cycles ahead from the subframe start time notified from the ONU 5 and the time length of one subframe. Next, the time correction unit 31 compares the predicted subframe start time several cycles ahead with the mobile station reception absolute time from the time extraction unit 30, and the maximum subframe not exceeding the mobile station reception absolute time The difference time between the start time and the slave station reception absolute time is calculated as the ONU reception time correction value. Here, the time length of one subframe is a system setting value, and is, for example, 1 ms in the case of LTE. In addition, although the description has been made here as several cycles ahead, this may be one cycle ahead, in order to allow time for processing. The ONU reception time correction value calculated by the time correction unit 31 is notified to the time conversion unit 18A.
 時刻変換部18Aでは、まず、ONU受信時刻補正値を加算して子局受信絶対時刻を補正することで、ONU5が子局装置2からデータを受信するONU受信時刻を求める。次に、時刻変換部18Aでは、OLT4が管理する現在のLocal TimeとGPS抽出部14からの絶対時刻とから、求めたONU受信時刻をLocal Timeへ変換して、ONUデータ受信タイミングとして出力する。ONUデータ受信タイミングは、PONスケジューラ19へと通知される。一方、リソース変換部12では、無線上りスケジューリング情報に含まれる割当リソースから上りデータ量を算出し、PONスケジューラ19へと通知する。PONスケジューラ19では、子局装置2毎、UE3毎の、Local Timeへ変換されたONUデータ受信タイミングと上りデータ量とから、OLT4-ONU5間の往復遅延時間も加味して、ONU5毎の光上りスケジューリングを行い、MPCP部17へと通知する。PONスケジューラ19の処理は、実施の形態1で説明した処理と同じであるため、ここでは、詳しい説明は省略する。MPCP部17では、この光上りスケジューリング情報を基にGateフレームを生成し、ONU5へと通知する。 The time conversion unit 18A first calculates the ONU reception time at which the ONU 5 receives data from the slave station apparatus 2 by adding the ONU reception time correction value and correcting the slave station reception absolute time. Next, the time conversion unit 18A converts the obtained ONU reception time into Local Time from the current Local Time managed by the OLT 4 and the absolute time from the GPS extraction unit 14, and outputs it as ONU data reception timing. The ONU data reception timing is notified to the PON scheduler 19. On the other hand, the resource conversion unit 12 calculates the amount of uplink data from the allocation resource included in the wireless uplink scheduling information, and notifies the PON scheduler 19 of the amount. The PON scheduler 19 takes into consideration the ONU data reception timing and upstream data amount converted to Local Time for each slave station device 2 and for each UE 3, and also takes into consideration the round trip delay time between the OLT 4 and the ONU 5, to thereby perform the optical uplink The scheduling is performed and notified to the MPCP unit 17. Since the process of the PON scheduler 19 is the same as the process described in the first embodiment, the detailed description is omitted here. The MPCP unit 17 generates a Gate frame on the basis of the optical uplink scheduling information and notifies the ONU 5 of it.
 以上により、実施の形態2においても、上記の実施の形態1と同様に、ONU5でSUBFRAME.indicationフレームを受信すること、および、当該フレームの受信時刻をOLT4へ通知することにより、親局装置1、子局装置2、ONU5、OLT4における処理遅延、および、子局装置2-ONU5間、親局装置1-OLT4間の、伝送遅延に起因するずれを含む、ONU5での受信時刻を、OLT4が正確に把握することができる。それにより、ONU5での無線データ蓄積時間を減らすリソース割当が可能となり、親局装置1が管理する、UE3毎、子局装置2毎の、無線上りスケジューリング情報と、PONにおける光上りスケジューリング情報とを正確に合致させることができる。このように、実施の形態1では、無線通信において、ONU5における子局装置2からのデータの受信時刻を正確にOLT4が把握することで、上りデータの送信の遅延時間を抑えた、光上りスケジューリングを可能にする。 As described above, also in the second embodiment, as in the above-described first embodiment, the ONU 5 receives SUBFRAME. By receiving the indication frame and notifying the OLT 4 of the reception time of the frame, processing delay in the master station device 1, slave station device 2, ONU 5, OLT 4 and the slave station devices 2-ONU 5, parent The OLT 4 can accurately grasp the reception time at the ONU 5 including the deviation between the station apparatus 1 and the OLT 4 due to the transmission delay. As a result, resource allocation for reducing the wireless data storage time in the ONU 5 becomes possible, and the wireless uplink scheduling information for each UE 3 and each slave station 2 managed by the master station device 1 and the optical uplink scheduling information in the PON It can be matched exactly. As described above, in the first embodiment, the optical uplink scheduling in which the delay time of transmission of uplink data is suppressed by the OLT 4 accurately grasping the reception time of data from the slave station device 2 in the ONU 5 in wireless communication. Make it possible.
 さらに、実施の形態2においては、無線上りスケジューリング情報に含まれるタイミング情報が子局受信絶対時刻であった場合にも、親局装置1が管理するUE3毎、子局装置2毎の、無線上りスケジューリングとPONにおける光上りスケジューリング情報とを、ONU5でのSUBFRAME.indicationフレームの受信およびその情報のOLT4への通知により、正確に合致させることで、ONU5での無線データ蓄積時間を減らしたリソース割当を実施可能となり、上り遅延時間が低減される。 Furthermore, in the second embodiment, even when the timing information included in the wireless uplink scheduling information is the slave station reception absolute time, the wireless uplink for each UE 3 and slave station 2 managed by the master station 1 is also possible. The scheduling and the optical uplink scheduling information in PON can be compared with SUBFRAME. By accurately matching the reception of the indication frame and the notification to the OLT 4 of the information, resource allocation in which the wireless data storage time in the ONU 5 is reduced can be implemented, and the uplink delay time is reduced.
 1 親局装置、2 子局装置、3 無線端末(UE)、4 光加入者終端装置(OLT)、5 光ネットワークユニット(ONU)、6 光伝送路、7 GPS受信器、11 無線情報抽出部、12 リソース変換部、13 番号抽出部、14 GPS抽出部、15 時刻抽出部、16 時刻推定部、17 MPCP部、18 時刻変換部、19 PONスケジューラ、20 MUX、21 光送受信部、22 番号抽出部、23 GPS抽出部、24 時刻検出部、25 フレーム生成部、26 MPCP部、27 送信制御部、28 光送受信部、29 MUX。 1 master station apparatus, 2 slave station apparatus, 3 radio terminal (UE), 4 optical subscriber terminal (OLT), 5 optical network unit (ONU), 6 optical transmission line, 7 GPS receiver, 11 radio information extraction unit , 12 resource conversion unit, 13 number extraction unit, 14 GPS extraction unit, 15 time extraction unit, 16 time estimation unit, 17 MPCP unit, 18 time conversion unit, 19 PON scheduler, 20 MUX, 21 light transmitting / receiving unit, 22 number extraction Unit, 23 GPS extractor, 24 time detector, 25 frame generator, 26 MPCP unit, 27 transmission controller, 28 light transmitter and receiver, 29 MUX.

Claims (3)

  1.  親局装置に接続された局側装置と、
     端末との間で無線通信を行う子局装置に接続された端末側装置と、
     前記局側装置と前記端末側装置とを接続する光伝送路と
     を備え、
     前記端末側装置は、
     前記端末が無線データを送信する送信タイミングを示す無線データ送信タイミング情報を前記子局装置から受信して、前記無線データ送信タイミング情報を受信した受信時刻を検出する受信時刻検出部と、
     前記受信時刻を前記局側装置に通知する通知フレームを送信する送信部と
     を備え、
     前記局側装置は、
     前記親局装置が管理する無線上りスケジューリング情報を抽出する無線情報抽出部と、
     前記送信部が送信する前記通知フレームから前記受信時刻を抽出する時刻抽出部と、
     前記時刻抽出部が抽出した前記受信時刻に基づいて、前記無線上りスケジューリング情報に対応するデータを前記端末側装置が前記子局装置から受信する推定受信時刻を算出する推定時刻算出部と、
     前記推定受信時刻と前記無線上りスケジューリング情報とに基づいて、前記端末側装置から前記局側装置へデータ送信を行うための光上りスケジューリング情報を生成するスケジューリング部と、
     前記光上りスケジューリング情報を前記端末側装置に通知する通知部と
     を備えた、
     光通信システム。
    A station-side device connected to a master station device;
    A terminal-side device connected to a slave station device performing wireless communication with the terminal;
    An optical transmission line connecting the station apparatus and the terminal apparatus;
    The terminal device is
    A reception time detection unit that receives, from the slave station apparatus, wireless data transmission timing information indicating transmission timing at which the terminal transmits wireless data, and detects a reception time at which the wireless data transmission timing information is received;
    A transmitter configured to transmit a notification frame for notifying the reception device of the reception time.
    The station-side device
    A radio information extraction unit for extracting radio uplink scheduling information managed by the parent station apparatus;
    A time extraction unit that extracts the reception time from the notification frame transmitted by the transmission unit;
    An estimated time calculation unit that calculates an estimated reception time at which the terminal device receives data corresponding to the wireless uplink scheduling information from the slave station apparatus based on the reception time extracted by the time extraction unit;
    A scheduling unit configured to generate optical uplink scheduling information for transmitting data from the terminal device to the station device based on the estimated reception time and the wireless uplink scheduling information;
    And a notification unit for notifying the optical uplink scheduling information to the terminal device.
    Optical communication system.
  2.  前記無線上りスケジューリング情報が、前記無線データの無線フレーム番号及びサブフレーム番号を含み、
     前記通知フレームは、前記受信時刻と、前記受信時刻に対応する前記無線データの無線フレーム番号およびサブフレーム番号とを含み、
     前記推定時刻算出部は、
     前記無線上りスケジューリング情報から、前記無線フレーム番号及びサブフレーム番号を抽出する第1の番号抽出部と、
     前記通知フレームから、前記無線フレーム番号及びサブフレーム番号を抽出する第2の番号抽出部と、
     前記第1の番号抽出部で抽出した前記無線フレーム番号及び前記サブフレーム番号と前記第2の番号抽出部で抽出した前記無線フレーム番号及び前記サブフレーム番号とを照合することによって、前記時刻抽出部によって抽出された前記通知フレームの前記受信時刻の中から、前記第1の番号抽出部で抽出した前記無線フレーム番号及び前記サブフレーム番号に対応する受信時刻を検索し、検索により得られた前記受信時刻を前記推定受信時刻として出力する時刻推定部と
     を有する、
     請求項1に記載の光通信システム。
    The radio uplink scheduling information includes a radio frame number and a subframe number of the radio data,
    The notification frame includes the reception time, and a radio frame number and a subframe number of the radio data corresponding to the reception time.
    The estimated time calculation unit
    A first number extraction unit for extracting the radio frame number and the subframe number from the radio uplink scheduling information;
    A second number extraction unit for extracting the radio frame number and the subframe number from the notification frame;
    The time extraction unit is performed by collating the radio frame number and the subframe number extracted by the first number extraction unit with the radio frame number and the subframe number extracted by the second number extraction unit. The reception time corresponding to the radio frame number and the subframe number extracted by the first number extraction unit is searched from the reception times of the notification frame extracted by Outputting a time as the estimated reception time;
    The optical communication system according to claim 1.
  3.  前記無線上りスケジューリング情報が、前記子局装置が前記端末から前記無線上りスケジューリング情報に対応する無線データを受信する子局受信時刻の情報を含み、
     前記推定時刻算出部は、
     前記無線上りスケジューリング情報から前記子局受信時刻を抽出する子局時刻抽出部と、
     前記時刻抽出部が抽出した前記受信時刻と前記子局受信時刻との差分時間を求め、当該差分時間を時刻補正値として出力する時刻補正部と、
     前記時刻補正値に基づいて前記子局受信時刻を補正することで前記推定受信時刻を算出する時刻算出部と
     を有する、
     請求項1に記載の光通信システム。
    The radio uplink scheduling information includes information on a slave station reception time at which the slave station apparatus receives radio data corresponding to the radio uplink scheduling information from the terminal;
    The estimated time calculation unit
    A slave station time extraction unit that extracts the slave station reception time from the wireless uplink scheduling information;
    A time correction unit which obtains a difference time between the reception time extracted by the time extraction unit and the slave station reception time, and outputs the difference time as a time correction value;
    A time calculation unit that calculates the estimated reception time by correcting the slave station reception time based on the time correction value;
    The optical communication system according to claim 1.
PCT/JP2017/028414 2017-08-04 2017-08-04 Optical communication system WO2019026281A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2019533864A JP6599063B2 (en) 2017-08-04 2017-08-04 Optical communication system
PCT/JP2017/028414 WO2019026281A1 (en) 2017-08-04 2017-08-04 Optical communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2017/028414 WO2019026281A1 (en) 2017-08-04 2017-08-04 Optical communication system

Publications (1)

Publication Number Publication Date
WO2019026281A1 true WO2019026281A1 (en) 2019-02-07

Family

ID=65233369

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2017/028414 WO2019026281A1 (en) 2017-08-04 2017-08-04 Optical communication system

Country Status (2)

Country Link
JP (1) JP6599063B2 (en)
WO (1) WO2019026281A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009065443A (en) * 2007-09-06 2009-03-26 Hitachi Communication Technologies Ltd Communication system, and device thereof
WO2014077168A1 (en) * 2012-11-14 2014-05-22 日本電信電話株式会社 Optical communication system, optical communication method, higher-level device, and optical line terminal
JP2017085356A (en) * 2015-10-28 2017-05-18 日本電信電話株式会社 Terminal station device and band allocation method
JP2017092714A (en) * 2015-11-10 2017-05-25 Kddi株式会社 PON system and transmission method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009065443A (en) * 2007-09-06 2009-03-26 Hitachi Communication Technologies Ltd Communication system, and device thereof
WO2014077168A1 (en) * 2012-11-14 2014-05-22 日本電信電話株式会社 Optical communication system, optical communication method, higher-level device, and optical line terminal
JP2017085356A (en) * 2015-10-28 2017-05-18 日本電信電話株式会社 Terminal station device and band allocation method
JP2017092714A (en) * 2015-11-10 2017-05-25 Kddi株式会社 PON system and transmission method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TASHIRO, T ET AL.: "A Novel DBA Scheme for TDM- PON based Mobile Fronthaul", OPTICAL FIBER COMMUNICATION CONFERENCE, 2014, pages 1 - 3, XP055567941 *

Also Published As

Publication number Publication date
JPWO2019026281A1 (en) 2019-11-07
JP6599063B2 (en) 2019-10-30

Similar Documents

Publication Publication Date Title
JP6742512B2 (en) Integrated Mobile and TDM-PON Uplink MAC Scheduling for Mobile Fronthaul
US20150208347A1 (en) Optical wireless access system
EP2953297B1 (en) Optical-wireless access system
US20170250777A1 (en) Band control system, band control apparatus and communication apparatus
CN111602349B (en) Method, device and system for time synchronization
US10924373B2 (en) Optical line terminal of optical network and uplink scheduling method
CN113938393A (en) Bandwidth allocation device and bandwidth allocation method
JP5556921B1 (en) Subscriber side apparatus registration method and optical network system
CN113329487B (en) Method and device for sending and receiving scanned beams and computer readable storage medium
US20170294955A1 (en) Radio control device and radio relay device
JP2012049942A (en) Bandwidth allocation controller and bandwidth allocation control program
JP2006245800A (en) W-cdma base station
JP2018007171A (en) Communication device and radio resource allocation method
CN106664234B (en) WDM/TDM-PON system and transmission start time correction method thereof
WO2016070846A1 (en) Working channel adjustment method, device and system, onu, and olt
KR20170010006A (en) Optical packet sending method and device, processing method and optical switching device
JP6381392B2 (en) PON system, OLT, ONU, and transmission method
JP2018093362A (en) Communication control device, radio communication device, and delay adjustment method
US20210227559A1 (en) Scheduling in wireless communication networks
US10505657B2 (en) Terminal station device and bandwidth allocation method
JP6599063B2 (en) Optical communication system
JP6568642B2 (en) Terminal station apparatus and bandwidth allocation method
US20190182836A1 (en) Optical transmission device and bandwidth allocation method
JP6646605B2 (en) Terminal station apparatus and band allocation method
JP2016213665A (en) Communication system and communication device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17920337

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2019533864

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17920337

Country of ref document: EP

Kind code of ref document: A1