JP2010252176A - Communication system, communication method, and communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a communication system in which downloading by using a plurality of communication devices through a shared passive optical network can be performed in a short time; a communication method; and the communication device. <P>SOLUTION: A communication system 301 includes: a plurality of house-side devices 102; and a station-side device 101 which communicates with the plurality of house-side devices 102 through the shared passive optical network and broadcasts download data that should be downloaded by the plurality of house-side devices 102 themselves to the plurality of house-side devices 102. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a communication system, a communication method, and a communication apparatus, and in particular, in a PON (Passive Optical Network) which is a medium sharing type communication in which a plurality of home apparatuses share a medium and transmit data. The present invention relates to a communication system, a communication method, and a communication device that download common data.

  One form of realizing FTTH (Fiber To The Home) that provides a network access service to each home by optical fiber is PON (Passive Optical Network). The feature of PON is that it shares a part of the optical fiber that connects between the home side equipment (ONU (Optical Network Unit)) and the station side equipment (OLT (Optical Line Terminal)) installed in each home. By doing so, an optical access service can be provided at a low cost.

  Non-Patent Document 1 describes one method of PON. All information including user information passing through the PON and control information for managing and operating the PON is in the form of an Ethernet (registered trademark) frame. An EPON (Ethernet (registered trademark) PON) to be communicated, an EPON access control protocol (MPCP (Multi-Point Control Protocol)), and an OAM (Operations, Administration and Maintenance) protocol are defined. By exchanging MPCP frames between the station side device and the home side device, the home side device joins and leaves, and uplink access multiplexing control is performed.

  In PON, all ONUs can physically receive data transmitted from the OLT to the optical fiber. Therefore, in the PON, an ONU number to receive the frame is indicated by an identifier called LLID (Logical Link ID) embedded in the preamble portion of the frame, and the ONU refers to the LLID so that only the frame addressed to the own device is displayed. use. In other words, the ONU logically receives only the frames that match its own LLID among the physically received frames.

  As the LLID, a “unicast LLID” that the OLT individually assigns to the ONU when communicating with the ONU, and a “broadcast LLID” that is an identifier indicating a frame to be received by all the ONUs are defined.

  Next, remote download is described. In a network system including FTTH, a function for adding a new function and correcting a problem is often required. As a method for realizing such a function, there is a method of downloading a software program executed by a CPU in a device in the network system or a design data of an FPGA (Field Programmable Gate Array) in the device in the network system.

  As an example of such a communication system that performs remote download, for example, Patent Document 1 discloses the following configuration, that is, a central station that holds a program, the central station, and a communication line Is a wireless communication system comprising a plurality of base stations which are connected to each other and hold a program downloaded from the central station and perform processing based on the program, wherein the base station performs program version data at a predetermined time. The version check processing means for comparing the version data held in the central station with the version data held in the base station, and a program download request when the version data does not match. Download control processing means for sending to the central office.

JP-A-8-6770

IEEE Std 802.3ah (registered trademark) -2004

  However, in the configuration described in Patent Document 1, since downloading is performed individually for each base station to be downloaded, when the number of base stations to be downloaded is large, downloading of all base stations is completed. It takes a long time to complete.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a communication system, a communication method, and a communication apparatus that can download a plurality of communication apparatuses via a common passive optical network in a short time.

  In order to solve the above problems, a communication system according to an aspect of the present invention communicates with a plurality of home devices via a common passive optical network and a plurality of home devices. A station side device that broadcasts download data to be downloaded by the side device itself to the plurality of home side devices.

  A communication system according to another aspect of the present invention communicates with a plurality of home-side devices via a common passive optical network with a plurality of home-side devices, and is used by the plurality of home-side devices. Among the data, the common management data used in common by the plurality of home-side devices is broadcast to the plurality of home-side devices, and information indicating whether the home-side device has successfully received the common management data A station-side device that is acquired from the home-side device.

  Preferably, the station-side device selects the home-side device to be broadcast before performing the broadcasting to the plurality of home-side devices, transmits a selection notification to the selected home-side device, and The side apparatus receives the selection notification, receives broadcast data newly broadcast by the station side apparatus, and changes the operation content based on the received broadcast data.

  More preferably, the station-side device stores the selected home-side device, and after performing the broadcast, obtains information on whether or not the broadcast data has been normally received from the stored home-side device. If there is a home device that has not normally received the broadcast data, the broadcast data is retransmitted to the home device that has not normally received the broadcast data.

  Preferably, the station side device broadcasts information on the types of broadcast data to be broadcast to the plurality of home side devices before performing the broadcast to the plurality of home side devices, and the home side device Based on the information received from the station side device, it is determined whether or not the broadcast data should be used. When it is determined that the broadcast data should be used, the operation content is changed based on the broadcast data.

  More preferably, when the home device determines that the broadcast data should be used, the home device transmits a response to the station device, and the station device transmits the response to the home device that has transmitted the response. After storing and performing the broadcast, the information about whether or not the broadcast data has been normally received is acquired from the stored home device, and the home device that has not normally received the broadcast data is If it exists, the broadcast data is retransmitted to the home device that has not received the broadcast data normally.

  Preferably, the station-side device divides broadcast data to be broadcast to the plurality of home-side devices into a plurality of blocks and broadcasts the blocks to the plurality of home-side devices, respectively. Is received from the plurality of home-side devices, and when there is the home-side device that did not normally receive the block, the information is normally received from the plurality of blocks. The block that did not exist is retransmitted to the home device that did not receive the block normally.

  Preferably, the station-side device divides broadcast data to be broadcast to the plurality of home-side devices into a plurality of blocks and broadcasts the blocks to the plurality of home-side devices, respectively. Before the broadcast is selected, the home device is selected from the plurality of home devices to notify the station device whether or not the block has been normally received, and the selected home side is selected. The home-side device that has transmitted a response instruction to the device and has received the response instruction transmits information on whether or not the block has been normally received from the station-side device to the station-side device, and the station-side device When receiving the information that the block has been normally received, broadcasts an untransmitted block of the plurality of blocks to the plurality of home-side devices.

  In order to solve the above-described problem, a communication method according to an aspect of the present invention includes a plurality of home-side devices and a station-side device that communicates with the plurality of home-side devices via a common passive optical network. A communication method in a communication system provided, wherein the station side device broadcasts download data to be downloaded by the plurality of home side devices themselves to the plurality of home side devices, and the plurality of home side devices Receiving the download data.

  A communication method according to another aspect of the present invention is a communication in a communication system including a plurality of home-side devices and a station-side device that communicates with the plurality of home-side devices via a common passive optical network. A method in which the station side device broadcasts common management data commonly used by the plurality of home side devices among the management data used by the plurality of home side devices to the plurality of home side devices. And the station-side device acquires from the home-side device information about whether the home-side device has received the common management data normally.

  In order to solve the above problems, a communication device according to an aspect of the present invention is a communication device that communicates with a plurality of other devices via a common passive optical network, and the plurality of other devices themselves. A data generation unit that generates download data to be downloaded by the computer, and a transmission unit that broadcasts the download data generated by the data generation unit to the plurality of other devices.

  A communication device according to another aspect of the present invention is a communication device that communicates with a plurality of other devices via a common passive optical network, and includes management data used by the plurality of other devices. A transmitter that broadcasts common management data commonly used by the plurality of other devices to the plurality of other devices, and information indicating whether the other devices have received the common management data normally. And a control unit that is obtained from another device.

  A communication apparatus according to still another aspect of the present invention is a communication apparatus that communicates with another apparatus via a common passive optical network, and downloads the download data broadcast from the other apparatus. If it is determined that the download data should be downloaded based on the information obtained from the other device, the transition to the download state and the newly received download data is obtained. Change the operation contents, and then transition to the non-download state.

  According to the present invention, a plurality of communication devices can be downloaded in a short time via a common passive optical network.

It is a block diagram which shows schematic structure of the PON system which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of OLT which concerns on embodiment of this invention. It is a block diagram which shows schematic structure of ONU which concerns on embodiment of this invention. It is a sequence diagram which shows the operation | movement procedure of the download of the data in the PON system which concerns on embodiment of this invention. It is a sequence diagram which shows the procedure of the preparation operation before the broadcast start in the PON system which concerns on embodiment of this invention. It is a sequence diagram which shows the modification of the procedure of the preparation operation | movement before the broadcast start in the PON system which concerns on embodiment of this invention. It is the flowchart which defined the operation | movement procedure at the time of OLT broadcasting in the PON system which concerns on embodiment of this invention. It is the flowchart which defined the procedure of the modification of the operation | movement when OLT broadcasts in the PON system which concerns on embodiment of this invention. It is the flowchart which defined the operation | movement procedure at the time of ONU downloading data in the PON system which concerns on embodiment of this invention. (A)-(c) is a figure which shows the reception checklist which ONU which concerns on embodiment of this invention has. It is the flowchart which defined the operation | movement procedure at the time of OLT performing a download completion confirmation in the PON system concerning embodiment of this invention.

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

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

  Referring to FIG. 1, a PON system 301 includes an OLT 101 mainly installed in a telephone office, a plurality of ONUs 102-1 to 102-n mainly installed in each home, and an optical signal transmitted from the OLT 101. Are split and transmitted to the ONUs 102-1 to 102-n, the optical signals transmitted from the ONUs 102-1 to 102-n are converged and transmitted to the OLT 101, and the ONUs 102-1 to 102-n And a plurality of user terminals 111 to be connected. A plurality of user terminals may be connected to one ONU.

  The OLT 101 transmits the data received via the upper network 109 to the ONUs 102-1 to 102-n via the PON line 104 and the splitter 105, which are optical fibers. Further, the OLT 101 calculates the transmission start time and the transmission permission amount of the data stored in the buffer in the ONUs 102-1 to 102-n based on the reports transmitted from the ONUs 102-1 to 102-n, and instructs The grant in which the signal is inserted is transmitted to the ONUs 102-1 to 102-n via the PON line 104 and the splitter 105.

  For example, when the ONU 102-1 receives an uplink information frame from the user terminal 111 via the home network 110, the ONU 102-1 temporarily stores the uplink information frame in a buffer. When the ONU 102-1 receives a grant from the OLT 101, the ONU 102-1 notifies the OLT 101 of the length of data in its own buffer at a time designated by the grant.

  When the ONU 102-1 receives the grant in which the instruction signal is inserted from the OLT 101, based on the instruction signal, the ONU 102-1 transmits the data in its own buffer together with the report to the OLT 101.

FIG. 2 is a block diagram showing a schematic configuration of the OLT according to the embodiment of the present invention.
Referring to FIG. 2, the OLT 101 includes a reception unit 41, a transmission unit 42, a control frame processing unit (control unit and data generation unit) 43, a reception unit 44, a buffer memory 45, a transmission unit 46, Buffer memory 48.

  In the downlink direction, the reception unit 41 transfers the downlink data frame received from the upper network 109 to the buffer memory 48. The buffer memory 48 accumulates the downlink data frame received from the receiving unit 41.

  The control frame processing unit 43 generates a grant frame based on the report frame received from the receiving unit 44. The control frame processing unit 43 also generates other control frames and transfers them to the transmission unit 42. For example, the control frame processing unit 43 generates a control frame for download and outputs it to the transmission unit 42.

  Here, the control data for download includes management data used in the ONU. The management data includes common management data commonly used by each ONU and individual management data individually used by each ONU. The management data includes, for example, download data such as a program code executed by an ONU CPU (Central Processing Unit) and a configuration code used by an ONU FPGA (Field Programmable Gate Array). The management data includes, for example, operation instruction information for the ONU to perform various operations. The operation instruction information is, for example, a reset instruction from the OLT and configuration information of the storage area of the buffer memory.

  Further, the download data that is data to be downloaded by the ONU itself has a size of, for example, several hundred kilobytes to several megabytes. In EPON, it is necessary to transmit management data to a PON line in accordance with an Ethernet (registered trademark) frame format. For this reason, the OLT divides the management data into an appropriate size and broadcasts it to each ONU. That is, the OLT divides management data into a plurality of blocks and broadcasts them to each ONU. For example, when 50,100 bytes of management data are divided into 1,000-byte blocks for transmission, a total of 51 blocks are transmitted. Note that only the management data of 100 bytes is stored in the last block.

  The Ethernet (registered trademark) frame storing the block includes a sequence number indicating at least what number the block is in addition to the block. Also, check data for checking the validity of the data may be included.

  As described above, when the amount of management data is large, the control frame processing unit 43 divides the management data into a plurality of blocks, and generates a plurality of control frames each including the plurality of divided blocks.

  The transmission unit 42 transmits the downlink data frame stored in the buffer memory 48 and the control frame received from the control frame processing unit 43 to the ONU via the PON line 104.

  In the upstream direction, the receiving unit 44 receives an upstream frame from the ONU via the PON line 104. The receiving unit 44 determines whether it is a data frame or a control frame such as a report frame based on the header portion of the upstream frame. If the received frame is a data frame, the reception unit 44 transfers the data frame to the transmission unit 46 via the buffer memory 45. If the received frame is a control frame, the receiving unit 44 transfers the control frame to the control frame processing unit 43.

  The buffer memory 45 accumulates the data frame received by the receiving unit 44. The transmission unit 46 transmits the data frame stored in the buffer memory 45 to the upper network 109.

FIG. 3 is a block diagram showing a schematic configuration of the ONU according to the embodiment of the present invention.
Referring to FIG. 3, the ONU 102 includes a receiving unit 21, a transmitting unit 22, a control frame processing unit 23, a receiving unit 24, a buffer memory 25, a transmitting unit 26, an FPGA 27, a buffer memory 28, ROM 29.

  The control frame processing unit 23 includes a CPU 31, a ROM (Read Only Memory) 32 that is a nonvolatile memory, and a RAM (Random Access Memory) 33. In the ROM 32, a CPU program code, operation instruction information, and the like are written.

  When power is supplied by power-on, the CPU 31 boots up, that is, starts reading program code and operates. The RAM 33 is used as a work memory used when the CPU 31 is operating.

  The FPGA 27 is a general-purpose logic circuit whose circuit configuration can be changed by a configuration code written in the ROM 29. When power is supplied when the power is turned on, the FPGA 27 reads the configuration code from the ROM 29 to determine its own circuit configuration, and operates based on the determined circuit configuration. That is, in FIG. 3, the FPGA 27 is described separately from the other functional blocks, but what kind of processing is performed as the FPGA 27 is not predetermined. If the FPGA 27 and other blocks are electrically connected on the substrate, it is possible to perform functions such as “transmitting unit”, “receiving unit”, and “buffer memory” in the ONU shown in FIG.

  In the downstream direction, the receiving unit 21 receives an optical signal from the OLT and determines whether or not the frame is addressed to itself by reading the header portion of the frame. The receiving unit 21 captures the frame if the received frame is addressed to itself, and discards the frame if it is addressed to another ONU or a device connected to another ONU. More specifically, the receiving unit 21 identifies the LLID described in the frame received from the OLT via the PON line 104, and the unicast LLID or broadcast LLID set in the own apparatus is recorded. Only pass through.

  In addition, the receiving unit 21 determines whether it is a data frame or a control frame such as a grant frame based on the header portion of the captured frame. If the received frame is a data frame, the receiving unit 21 transfers the data frame to the transmitting unit 22 via the buffer memory 28. If the received frame is a control frame, the receiving unit 21 transfers the control frame to the control frame processing unit 23.

  The CPU 31 in the control frame processing unit 23 receives a control frame for download from the receiving unit 21 and downloads management data included in the control frame. Here, “download” in the present invention is data newly written from another device, which is data written in a storage unit such as a ROM in a certain device and determines the operation content of the CPU, FPGA, etc. Means to change. That is, the CPU 31 writes the program code and operation instruction information stored in the ROM 32 and the configuration code stored in the ROM 29 in the ROM 32 or a predetermined area in the ROM 29, so that it is based on newly received management data. It changes its own operation content and the operation content of the FPGA 27.

  When receiving a response instruction from the OLT, the CPU 31 generates a control frame including a response message and outputs the control frame to the transmission unit 26.

  When receiving the data frame from the receiving unit 21, the transmitting unit 22 transmits this data frame to the home-side network 110 to which a user terminal or the like is connected.

  When receiving the grant frame from the reception unit 21, the control frame processing unit 23 creates a report frame and transfers it to the transmission unit 26. The control frame processing unit 23 also executes control frame processing other than the grant frame from the OLT, generates a corresponding control frame as necessary, and transfers the control frame to the transmission unit 26.

  In the uplink direction, the reception unit 24 receives an uplink information frame, that is, a data frame from the user terminal, and transfers it to the buffer memory 25. The buffer memory 25 stores control frames and data frames transferred from the control frame processing unit 23 and the receiving unit 24, respectively.

  The control frame processing unit 23 transfers the frame accumulated in the buffer memory 25 to the transmission unit 26. The transmission unit 26 transmits the data frame received from the buffer memory 25 and the control frame received from the control frame processing unit 23 to the OLT. Here, the transmission unit 26 transmits the unicast LLID in the frame to be transmitted, regardless of whether the data frame is transmitted or the control frame is transmitted.

  FIG. 4 is a sequence diagram showing an operation procedure of data download in the PON system according to the embodiment of the present invention. Here, a case where the common management data is divided into N blocks will be described.

  Referring to FIG. 4, first, the OLT transmits a control frame for notifying "download start" to each ONU (SQ1).

  Next, each ONU receives a control frame indicating “download start” from the OLT, and transitions to a download state. Then, each ONU transmits a control frame indicating that it has transitioned to the download state to the OLT (SQ2).

  Next, the OLT receives a control frame indicating the transition from each ONU to the download state, puts block 1 out of the N blocks into a control frame that is an Ethernet (registered trademark) frame, and broadcast LLID. In the control frame and broadcast to each ONU (SQ3).

  Next, each ONU receives the control frame including the block 1 from the OLT, stores the block 1, and transmits Ack (Acknowledge) 1 indicating that the block 1 has been received normally to the OLT. (SQ4).

  Next, the OLT receives a control frame including Ack1 from each ONU, puts block 2 out of N blocks into a control frame which is an Ethernet (registered trademark) frame, and puts a broadcast LLID into the control frame. Broadcast to each ONU (SQ5).

  Next, each ONU receives a control frame including the block 2 from the OLT, saves the block 2, puts Ack2 indicating that the block 2 has been normally received, and transmits it to the OLT (SQ6). .

  Thereafter, the OLT and each ONU repeat transmission and reception of block 3 to block N-1. Then, the OLT broadcasts the block N (SQ7), and each ONU transmits an AckN in the control frame to the OLT (SQ8). Here, each of the ONUs updates the management data when all of the blocks 1 to N are successfully received.

  Next, the OLT receives a control frame including AckN from each ONU, and transmits a control frame indicating an inquiry as to whether or not the downloading of the blocks 1 to N is normally completed to each ONU (SQ9).

  Next, each ONU receives a control frame indicating an inquiry from the OLT, and transmits a control frame indicating whether or not the downloading of the blocks 1 to N is normally completed to the OLT (SQ10).

  Next, when the OLT receives a control frame indicating that the download of the blocks 1 to N is normally completed from each ONU, the OLT ends the download process. On the other hand, when the OLT receives a control frame indicating that the download of the blocks 1 to N has not been completed normally from at least one ONU (hereinafter referred to as an incomplete ONU), Block i (i = 1 to N) that could not be received normally is retransmitted to the incomplete ONU (SQ11).

  Next, the incomplete ONU receives the control frame including the block i from the OLT, saves the block i, puts Acki indicating that the block i has been normally received, and transmits it to the OLT (SQ12). ). The incomplete ONU updates the management data.

  Next, the OLT receives a control frame including Acchi from the incomplete ONU, and transmits a control frame indicating an inquiry as to whether or not the download of the blocks 1 to N is normally completed to the incomplete ONU (SQ13 ).

  Next, each ONU including the incomplete ONU receives a control frame indicating an inquiry from the OLT, and transmits a control frame indicating a state in which the download of the blocks 1 to N is normally completed to the OLT (SQ14).

  When the OLT receives a control frame indicating that the download of the blocks 1 to N is normally completed from each ONU, the OLT ends the download process.

  FIG. 5 is a sequence diagram showing the procedure of the preparation operation before the start of broadcasting in the PON system according to the embodiment of the present invention. FIG. 5 corresponds to the operations of sequences SQ1 and SQ2 shown in FIG. Here, a case where the OLT and the ONU-A and ONU-B are communicating will be described.

  Each ONU communicating with one OLT, that is, connected to one OLT, may have a mix of manufacturer, software version, and hardware version, and not all ONUs download the same management data Not necessarily the target.

  Therefore, before broadcasting the common management data to each ONU, the OLT grasps the ONU that should download the common management data, that is, the ONU to be downloaded. First, the OLT generates a control message that notifies “download start”, puts it in the control frame, and puts the broadcast LLID in the control frame and broadcasts it to the ONU-A and ONU-B (SQ21A and SQ21B).

  This control message includes the type of common management data in addition to the “download start” notification. The types of common management data include, for example, the manufacturer name, software version, and hardware version of the ONU to be downloaded. The type of common management data includes the type of device to be downloaded, that is, whether the common management data is a software program such as a CPU, FPGA data, or operation instruction information. The types of common management data include the version of the common management data itself, the size of the common management data, the size of the divided block of the common management data, and the date of the common management data.

  Next, the ONU-A and ONU-B confirm the control message included in the control frame received from the OLT, its own setting, version, and the like. That is, the ONU compares the type of the common management data indicated by the control message with its own setting and version, etc., and determines whether or not it satisfies the download conditions for the common management data (SQ22 and SQ24). .

  When the ONU-A determines that the download condition is satisfied, that is, the common management data should be downloaded (SQ23), the ONU-A transitions to the download state and transmits a control frame indicating the transition to the download state to the OLT. (SQ26).

  When the ONU-B determines that it does not satisfy the download condition (SQ25), it does not transition to the download state and transmits a control frame indicating that it has not transitioned to the download state to the OLT (SQ27). Even in the ONU-B that has not transitioned to the download state, the receiving unit 21 outputs a frame in which the broadcast LLID from the OLT is written to the CPU 31, but the CPU 31 discards this frame.

  Next, the OLT receives the control frame indicating that the ONU-A has transitioned to the download state and the control frame indicating that the ONU-B has not transitioned to the download state, and identifies the ONU-A that has entered the download state. A number, for example, a unicast LLID is stored, that is, ONU-A is added to the download target. This stored content is used in a download completion confirmation process described later (SQ28).

  FIG. 6 is a sequence diagram showing a modified example of the procedure of the preparation operation before the start of broadcasting in the PON system according to the embodiment of the present invention. FIG. 6 corresponds to the operations of sequences SQ1 and SQ2 shown in FIG.

  Referring to FIG. 6, before broadcasting the common management data to each ONU, the OLT selects an ONU to download the common management data, that is, an ONU to be downloaded. For example, the OLT stores information such as the setting and version of each ONU, and compares the type of common management data with the setting and version of each ONU and satisfies the download conditions for the common management data. Select ONU. Here, the OLT selects ONU-A as the ONU to be downloaded. Further, the OLT stores the identification number of the ONU-A selected as the download target, for example, the unicast LLID in order to perform a download completion confirmation process described later (SQ31).

  Next, the OLT generates a control message to notify “download start”, puts it in the control frame, and puts the ONU-A unicast LLID in the control frame and transmits it to the PON line (SQ32).

  Next, since the unicast LLID included in the control frame received from the OLT is its own unicast LLID, the ONU-A transitions to the download state (SQ33) and indicates that the transition to the download state has occurred. Is transmitted to the OLT (SQ34). In this download state, the ONU-A receives a newly broadcast control frame as data for determining its own operation content.

  FIG. 7 is a flowchart defining an operation procedure when the OLT performs broadcasting in the PON system according to the embodiment of the present invention. FIG. 7 corresponds to the operations of sequences SQ3, SQ5, and SQ7 shown in FIG. This flowchart shows a scheme in which the OLT transmits the next block in response to a response from the ONU to the transmission of the common management data block.

Referring to FIG. 7, first, the OLT sets a variable i = 1 (S1).
Next, the OLT calculates the total number of transmission blocks, that is, calculates the number of divided blocks of the common management data (S2).

Next, the OLT broadcasts the i-th block to each ONU (S3).
Next, when the OLT receives a response (Ack) from each ONU within a predetermined time after broadcasting the block (YES in S4), the OLT sets the variable i = i + 1 (S5).

  Next, when the variable i has not reached the total number of transmission blocks (NO in S6), the OLT broadcasts the i-th block to each ONU, that is, broadcasts the next block (S3).

  If the OLT does not receive a response from each ONU within a predetermined time from broadcasting the block (NO in S4), it retransmits the same block (S3).

  When the variable i reaches the total number of transmission blocks (YES in S6), the OLT ends the broadcast process.

  FIG. 8 is a flowchart defining a procedure of a modified example of the operation when the OLT broadcasts in the PON system according to the embodiment of the present invention. FIG. 8 corresponds to the operations of sequences SQ3, SQ5, and SQ7 shown in FIG. This flowchart shows a method of sequentially transmitting a block of common management data every time a predetermined time elapses.

Referring to FIG. 8, first, OLT sets variable i = 1 (S11).
Next, the OLT calculates the total number of transmission blocks, that is, calculates the number of divided blocks of the common management data (S12).

Next, the OLT broadcasts the i-th block to each ONU (S13).
Next, the OLT waits for a predetermined time until transmission of the next block (S14).

Next, the OLT sets the variable i = i + 1 (S15).
Next, when the variable i has not reached the total number of transmission blocks (NO in S16), the OLT broadcasts the i-th block to each ONU, that is, broadcasts the next block (S13).

  When the variable i reaches the total number of transmission blocks (YES in S16), the OLT ends the broadcast process.

  In the system shown in FIG. 7, unlike the system shown in FIG. 8, the next block is transmitted if a response from the ONU is returned without waiting for a predetermined time until the next block is transmitted. For this reason, there is an advantage that the time required to transfer all the blocks is shortened as compared with the method shown in FIG.

  On the other hand, when there are a plurality of ONUs to be downloaded and there is an ONU whose writing speed of common management data to the memory is slower than that of other ONUs, the OLT is executed before the ONU completes data writing. The next block may be sent. The method shown in FIG. 8 has an advantage that such a possibility can be eliminated by setting the waiting time until transmission of the next block to the maximum time required for the ONU to write the block to the memory.

  FIG. 9 is a flowchart defining an operation procedure when the ONU downloads data in the PON system according to the embodiment of the present invention. FIG. 9 corresponds to the operations of sequences SQ4, SQ6, and SQ8 shown in FIG. FIGS. 10A to 10C are diagrams showing reception checklists that the ONU according to the embodiment of the present invention has.

  Referring to FIGS. 9 and 10, the ONU has a “reception checklist” for recording success / failure of reception for each block. That is, the “reception checklist” indicates the progress of reception of the common management data.

  Here, the ONU recognizes the number N of blocks to be downloaded from the control frame received from the OLT in the sequence SQ1 shown in FIG. 4, and creates a reception checklist having N fields based on the number N of blocks. create.

  First, as shown in FIG. 10A, the ONU clears N fields in the reception check list to 0 (S21).

  Next, the ONU receives a control frame including the broadcast LLID from the OLT, and receives the i-th block included in the control frame (S22).

Next, the ONU writes the block in the ROM 32 or the like (S23).
Next, as shown in FIG. 10B, the ONU updates the i-th field of the reception check list to 1 indicating “Received” (S24).

  Next, when the ONU receives a response instruction from the OLT, that is, when the control frame received from the OLT in the sequence SQ1 includes an instruction to notify the block reception response (YES in S25), the OLT A response is transmitted to (S26). In this case, the ONU transmits, for example, a reception check list in a frame as a response.

  Next, when any of the N fields of the reception checklist is 0 (NO in S27), the ONU sets the variable i = i + 1 (S28) and receives the next block to be transmitted. (S22).

  On the other hand, as shown in FIG. 10C, the ONU updates the management data when all the N fields of the reception checklist are set to 1, that is, “received” (YES in S27). Perform (S29). More specifically, the CPU 31 and the FPGA 27 and the like in the ONU change various operation contents based on the new N blocks stored in the ROM 32 and the like. Then, the ONU shifts from the download state to the non-download state (S30).

  As described above, the operation data is updated after all the blocks are normally received, so that the management data before the update is maintained before all the blocks are normally received. For this reason, even when the power of the ONU is turned off during downloading, for example, the ONU can operate normally with the management data before update when the power is turned on next time.

  Further, after updating the reception check list (S24), if the ONU has not received a response instruction from the OLT (NO in S25), the ONU proceeds to step S27 as it is.

  FIG. 11 is a flowchart that defines an operation procedure when the OLT performs a download completion confirmation in the PON system according to the embodiment of the present invention. FIG. 11 corresponds to the operations of sequences SQ9 to SQ14 shown in FIG.

  Referring to FIG. 11, the OLT selects one of the ONUs to be downloaded recognized by the operation shown in FIG. 5 or 6 and selects the identification number of the selected ONU, for example, the unicast LLID as a variable onu. (S31).

  Next, the OLT inquires the selected ONU about the completion of download. In other words, the OLT puts the LLID of the variable onu in a control frame indicating an inquiry as to whether or not the download of the common management data has been completed normally and transmits it to the PON line (S32).

  Next, when the OLT receives a response indicating that the download is completed from the selected ONU (YES in S33), and when all the download completions of each ONU to be downloaded are confirmed (YES in S36), The download completion confirmation process ends.

  On the other hand, when the OLT receives a response indicating that the download has been completed from the selected ONU (YES in S33), there is an ONU for which download completion has not been confirmed among the ONUs to be downloaded. (NO in S36), an unconfirmed ONU is selected, and the identification number of the selected ONU, for example, a unicast LLID is substituted into the variable onu (S31).

  Further, when the OLT receives a response indicating that the download has not been completed from the selected ONU (NO in S33), based on the “reception checklist” acquired from the ONU, It is confirmed which block is not normally received, and an abnormally received block is transmitted to the OLT. That is, the OLT puts an abnormally received block in the control frame, puts the unicast LLID of the ONU in the control frame and transmits it to the PON line (S35), and performs the process of step S36.

  In this way, once the OLT has transmitted all the blocks, it checks whether or not each ONU has completed the download. If not, only the blocks that have not been normally received are individually retransmitted to the ONU. Send.

  With such a configuration, the ONU download can be completed even when a block is lost in the transmission path from the OLT to the ONU.

  By the way, in the configuration described in Patent Document 1, since downloading is individually performed for each base station to be downloaded, the download time and the bandwidth of the line for downloading are required for each base station.

  However, in the PON system according to the embodiment of the present invention, the OLT communicates with a plurality of ONUs via a common passive optical network, that is, the PON line 104, and a plurality of management data used by the plurality of ONUs. The common management data used in common by the ONUs is broadcast to a plurality of ONUs. With such a configuration, even when the number of ONUs in the PON is large, the download time can be reduced and the bandwidth of the PON line for downloading can be reduced.

  In the PON system according to the embodiment of the present invention, the OLT obtains information from the ONU whether or not the ONU has completed downloading of the common management data. With such a configuration, the OLT can grasp the download status of the common management data by the ONU and perform appropriate measures such as retransmission of the common management data.

  Further, as described in the sequence diagram of FIG. 6, in the PON system according to the embodiment of the present invention, the OLT selects an ONU to be broadcast before broadcasting to a plurality of ONUs, and selects the selected ONU. A selection notification, that is, a “download start” control message with a unicast LLID of the selected ONU is transmitted. The ONU receives the selection notification, receives the common management data newly broadcast by the OLT, and changes the operation content based on the received common management data. In this way, since the OLT mainly determines whether or not the ONU should download, there is no need to determine whether or not the common management data should be downloaded in the ONU. Can be reduced.

  Further, as described in the sequence diagram of FIG. 6 and the flowchart of FIG. 11, in the PON system according to the embodiment of the present invention, the OLT stores the ONU selected as the download target and broadcasts the common management data. After that, information on whether or not the download of the common management data is completed is acquired from the stored ONU. Then, when there is an ONU that has not completed downloading of the common management data, the OLT retransmits the common management data to the ONU. With such a configuration, in addition to being able to reduce the download time and download band, it is possible to reliably transmit common management data to each ONU.

  In addition, as described with reference to the sequence diagram of FIG. 5, in the PON system according to the embodiment of the present invention, before broadcasting to a plurality of ONUs, information on the type of common management data to be broadcast is set to a plurality of ONUs. Broadcast to. Then, the ONU determines whether or not the common management data should be used based on the information received from the OLT, and if it determines that it should be used, changes the operation content based on the common management data received from the OLT To do. As described above, the configuration in which the ONU decides whether to perform download or not by itself eliminates the need for the OLT to select the ONU from which the common management data is to be downloaded, thereby reducing the processing amount of the OLT.

  Further, as described in the sequence diagram of FIG. 5 and the flowchart of FIG. 11, in the PON system according to the embodiment of the present invention, when the ONU determines that the common management data should be downloaded, it responds to the OLT. Send. Then, the OLT stores the ONU that transmitted the response, broadcasts the common management data, and then obtains information from the stored ONU whether or not the download of the common management data has been completed. When there is an ONU that has not completed downloading of the common management data, the OLT retransmits the common management data to the ONU that has not completed downloading of the common management data. With such a configuration, in addition to being able to reduce the download time and download band, it is possible to reliably transmit common management data to each ONU.

  Further, as described in the flowcharts of FIGS. 7, 8 and 11, in the PON system according to the embodiment of the present invention, the OLT divides the common management data to be broadcast to a plurality of ONUs into a plurality of blocks. Broadcast to a plurality of ONUs. The OLT obtains information on whether or not the download of the common management data has been completed, that is, information on whether or not all the blocks have been normally received from each ONU. If it exists, the block that is not normally received among the plurality of blocks is retransmitted to the ONU. With such a configuration, the retransmission unit of the common management data can be reduced, so that the download time and the download band can be further reduced.

  In addition, as described with reference to the flowchart of FIG. 9, in the PON system according to the embodiment of the present invention, the ONU uses other information on whether or not to download download data broadcast from other devices. Obtain from the device. When the ONU determines that the download data should be downloaded based on this information, the ONU transitions to the download state, changes the operation content based on the newly received download data, and then enters the non-download state. Transition. By using such an ONU, it becomes possible to broadcast common management data to the ONU, and even when the number of ONUs in the PON is large, the download time is reduced and the bandwidth of the PON line for downloading Can be reduced.

  In the PON system according to the embodiment of the present invention, the OLT determines whether or not a response (Ack) is received from each ONU within a predetermined time from when the block is broadcast in step S4 shown in FIG. Although the configuration is to be confirmed, the configuration is not limited to this. The configuration may be such that an ONU that should send a response to the OLT is selected from each ONU to be downloaded, and the OLT confirms whether or not a response from the selected ONU has been received. That is, before broadcasting a plurality of blocks, the OLT selects an ONU that notifies the OLT of whether or not the block has been normally received from the plurality of ONUs, and sends the information to the selected ONU. Send response instructions. For example, in SQ21A and SQ21B shown in FIG. 5, the OLT responds to the selected ONU by including the identification number of the ONU that should transmit Ack to the OLT, for example, the unicast LLID, in the control message notifying "download start". Instruct. The ONU that has received the response instruction transmits information indicating whether or not the block has been normally received from the OLT to the OLT. When the OLT receives information that the block has been normally received, the OLT broadcasts an untransmitted block among the plurality of blocks to the plurality of ONUs.

  With such a configuration, Ack is transmitted only from a specific ONU, that is, it is possible to prevent Ack from being transmitted simultaneously from each ONU every time a block is transmitted. Can be prevented and the performance of the PON system can be improved.

  Further, in the PON system according to the embodiment of the present invention, the OLT is configured to acquire information about whether or not the download of the common management data has been normally completed from each ONU. However, the present invention is limited to this. is not. If the OLT is configured to acquire at least information about whether or not the common management data has been normally received from each ONU, even if the number of ONUs in the PON is large, the download time can be reduced and the download can be performed. The bandwidth of the PON line for performing can be reduced.

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

  21, 41 Receiving unit, 22, 42 Transmitting unit, 23 Control frame processing unit, 24, 44 Receiving unit, 25, 45 Buffer memory, 26, 46 Transmitting unit, 27 FPGA, 28, 48 Buffer memory, 29, 32 ROM, 31 CPU, 33 RAM, 43 Control frame processing unit (control unit and data generation unit), 101 OLT, 102, 102-1 to 102-n ONU, 105 splitter, 111 user terminal, 301 PON system.

Claims (13)

A plurality of home-side devices;
A station-side device that communicates with the plurality of home-side devices via a common passive optical network and broadcasts download data to be downloaded by the plurality of home-side devices to the plurality of home-side devices. Communications system. A plurality of home-side devices;
Communicating with the plurality of home side devices via a common passive optical network, out of the management data used by the plurality of home side devices, the common management data used in common by the plurality of home side devices A communication system comprising: a station-side device that broadcasts to a plurality of home-side devices and acquires from the home-side device information about whether the home-side device has normally received the common management data. The station-side device selects the home-side device to be broadcasted before performing the broadcast to the plurality of home-side devices, and transmits a selection notification to the selected home-side device,
3. The device according to claim 1, wherein the home side device receives the selection notification, receives broadcast data newly broadcast by the station side device, and changes an operation content based on the received broadcast data. Communications system.   The station-side device stores the selected home-side device, performs the broadcast, obtains information on whether or not the broadcast data has been normally received from the stored home-side device, and transmits the broadcast The communication system according to claim 3, wherein when there is the home device that has not normally received data, the broadcast data is retransmitted to the home device that has not normally received the broadcast data. The station side device broadcasts information on the types of broadcast data to be broadcast to the plurality of home side devices before performing the broadcast to the plurality of home side devices,
The home-side device determines whether or not to use the broadcast data based on the information received from the station-side device, and determines that the home-side device should use the operation content based on the broadcast data. The communication system according to claim 1 or 2 to be changed. If the home device determines that the broadcast data should be used, it sends a response to the station device,
The station-side device stores the home-side device that has transmitted the response, and after performing the broadcast, acquires information on whether or not the broadcast data has been normally received from the stored home-side device. ,
The communication system according to claim 5, wherein when there is the home device that has not normally received the broadcast data, the broadcast data is retransmitted to the home device that has not normally received the broadcast data. The station-side device divides broadcast data to be broadcast to the plurality of home-side devices into a plurality of blocks and broadcasts them to the plurality of home-side devices,
The station-side device acquires information on whether or not the plurality of blocks have been normally received from the plurality of home-side devices, and when there is the home-side device that has not normally received the block, The communication system according to claim 1 or 2, wherein the block that has not been normally received among a plurality of blocks is retransmitted to the home-side device that has not normally received the block. The station-side device divides broadcast data to be broadcast to the plurality of home-side devices into a plurality of blocks and broadcasts them to the plurality of home-side devices,
The station-side device notifies the station-side device of information on whether or not the block has been normally received from the plurality of home-side devices before broadcasting the plurality of blocks. Select a device, send a response instruction to the selected home device,
The home-side device that has received the response instruction transmits information on whether or not the block has been normally received from the station-side device to the station-side device,
3. The station side device, when receiving the information that the block is normally received, broadcasts an untransmitted block of the plurality of blocks to the plurality of home side devices. Communication system. A communication method in a communication system comprising a plurality of home-side devices and a station-side device that communicates with the plurality of home-side devices via a common passive optical network,
The station-side device broadcasting download data to be downloaded by the plurality of home-side devices to the plurality of home-side devices;
A plurality of home-side devices receiving the download data. A communication method in a communication system comprising a plurality of home-side devices and a station-side device that communicates with the plurality of home-side devices via a common passive optical network,
The station side device broadcasts common management data used in common by the plurality of home side devices among the management data used by the plurality of home side devices to the plurality of home side devices;
A communication method including a step in which the station-side device acquires, from the home-side device, information as to whether or not the home-side device has successfully received the common management data. A communication device for communicating with a plurality of other devices via a common passive optical network,
A data generator for generating download data to be downloaded by the other devices themselves;
A communication device comprising: a transmission unit that broadcasts the download data generated by the data generation unit to the plurality of other devices. A communication device for communicating with a plurality of other devices via a common passive optical network,
Among the management data used by the plurality of other devices, a transmitter that broadcasts common management data commonly used by the plurality of other devices to the plurality of other devices,
A communication device comprising: a control unit that obtains information from the other device as to whether or not the other device has received the common management data normally. A communication device that communicates with other devices via a common passive optical network,
When it is determined that the download data to be downloaded from the other device should be downloaded from the other device and it is determined that the download data should be downloaded based on the information, the download state A communication device that changes the operation content based on the newly received download data after transiting to, and then transits to a non-download state.

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