JP2012205277A - Data transmission device and program, data reception device and program, and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform transmission when a data transmission device performs data transmission to a plurality of data reception devices.SOLUTION: The invention relates a communication system comprising: a plurality of data reception devices; and a data transmission device transmitting transmission target data. The data transmission device transmits data, which is the transmission target data divided into a plurality of blocks, and a code related to error detection corresponding to each of the blocks to the data reception device. The data reception device confirms normality of the blocks received from the data transmission device by using the received codes, and constructs the transmission target data by using the blocks whose normality has been confirmed.

Description

  The present invention relates to a data transmission apparatus and program, a data reception apparatus and program, and a communication system, and can be applied to, for example, software distribution processing in an optical communication network system such as a PON (Passive Optical Network).

  As subscriber access systems in FTTH, systems using PON (Passive Optical Network) technology (Non-Patent Documents 1 to 5) are widely used. The PON system consists of an OLT (Optical Line Terminal) on the station side (telecom carrier side) and an ONU (Optical Line Unit) on the subscriber premises. The optical fiber connected to the OLT is branched by an optical splitter. Therefore, the connection configuration is one-to-many.

  If there is any problem with the ONU control software, it is not efficient to go to the place where it is installed and replace the ONU main unit or update the software. Download the ONU control software remotely from the OLT. If it does, efficiency is good.

  As a conventional technique for performing remote download in the PON system, there is a technique described in Patent Document 1. The technique described in Patent Document 1 reduces the influence on the user frame on the optical transmission path by dividing the download data into a predetermined size, and the download data on the ONU is temporarily stored because each download data becomes smaller. This can contribute to the saving of the memory area stored in the memory.

JP 2008-252245 A

Edited by Nippon Telegraph and Telephone Corporation, “GE-PON Technology, 1st PON”, NTT Technical Journal, August 2005, pp. 71-74 Edited by Nippon Telegraph and Telephone Corporation, “GE-PON Technology, 2nd IEEE 802.3ah Standard”, NTT Technical Journal, September 2005, pp. 91-94 Edited by Nippon Telegraph and Telephone Corporation, “GE-PON Technology, 3rd DBA Function”, NTT Technical Journal, October 2005, pp. 67-70 Edited by Nippon Telegraph and Telephone Corporation, “GE-PON Technology, 4th GE-PON System Technology”, NTT Technical Journal, November 2005, pp. 59-61 Edited by Nippon Telegraph and Telephone Corporation, "GE-PON Technology, 5th Future Standardization", NTT Technology Journal, December 2005, pp. 51-54

  In the PON system, data transmission from the OLT to the ONU (hereinafter referred to as “downlink transmission”) is because the transmission path for each user is only branched from the trunk fiber by an optical splitter, and therefore broadcast as physical layer data. (PON broadcast). However, since communication with individual ONUs cannot be identified with this, individual ONUs are identified using a field in a frame called LLID (Logical Link ID) to establish a logical link.

  In the technology described in Patent Document 1, consideration is given to reducing the influence of a user frame when downloading control software, but efficient downloading is not considered. That is, the OLT divides the software data into frames and transmits them. The ONU returns an acknowledgment (ACK) to the OLT every time it receives each frame, and the OLT transmits the next data frame by receiving the ACK. To do. However, if each ONU is delayed due to different installation distances from the OLT, etc., or there is some problem on the transmission path, the software data does not reach each ONU, or the software data reaches the ONU, but the ACK There may be cases where the OLT does not reach. In this case, the control software is downloaded for each logical link in order to prevent an influence on the progress of the mutual ONU download.

  That is, according to the technology described in Patent Document 1, the download data of the control software needs to be transmitted to each ONU. When the connection between the OLT and the ONU is 1: n, the OLT needs to transmit the download data n times. There was a problem that there was bad efficiency.

  Therefore, when transmitting data from a data transmission device (for example, OLT) to a plurality of data reception devices (for example, ONUs), a data transmission device and program that can be efficiently transmitted, and a data reception device And programs and communication systems are preferred.

  A first aspect of the present invention is a communication system including a plurality of data receiving devices and a data transmitting device that transmits transmission target data to the receiving communication device. (1) The data transmitting device is (1-1) Data holding means for holding data obtained by dividing the transmission target data into a plurality of blocks, and a code related to error detection corresponding to each block; (1-2) at least for each of the data receiving devices A notification means for transmitting notification information including the code corresponding to each block; (1-3) a block data frame in which a block held by the data holding means and a sequence number related to the block are inserted; A block data frame transmitter that generates and transmits the generated block data frame to the data receiving device by broadcast processing. (2) Each of the data receiving devices includes (2-1) notification receiving means for receiving notification information from the data transmitting device, and (2-2) a broadcast from the data transmitting device. Using block data frame receiving means for receiving block data frames transmitted by communication processing, and (2-3) codes corresponding to the respective blocks included in the notification information notified from the data transmitting apparatus A normality checking means for checking the normality of the block inserted in each block data frame received by the block data frame receiving means; and (2-4) a block whose normality has been confirmed by the normality checking means. And data reconstructing means for reconstructing the transmission target data.

  According to a second aspect of the present invention, in a data transmission apparatus that transmits transmission target data to a plurality of data reception apparatuses, (1) data obtained by dividing the transmission target data into a plurality of blocks and error detection corresponding to each block. Data holding means for holding the code; (2) notification means for transmitting notification information including at least the code corresponding to each block to each of the data receiving devices; and (3) the data Block data frame transmission means for generating a block data frame in which a block held by the holding means and a sequence number related to the block are inserted, and transmitting the generated block data frame to the data receiving apparatus by broadcast processing It is characterized by having.

  According to a third aspect of the present invention, in the data reception device that receives the transmission target data from the data transmission device, (1) notification information including a code related to error detection corresponding to each of the blocks divided from the transmission target data, A notification receiving means for receiving from the data transmitting device; and (2) a block divided from the transmission target data transmitted from the data transmitting device by broadcast processing and a sequence number related to the block are inserted. Block data frame receiving means for receiving the received block data frame, and (3) the block data frame receiving means using a code corresponding to each block included in the notification information notified from the data transmitting apparatus. A health checker that checks the health of the blocks inserted in each block data frame received by the When, and having a (4) using a block normality is confirmed by the health check unit, data reconstruction means for reconstructing the transmitted data.

  According to a fourth aspect of the present invention, there is provided a data transmission program in which (1) a computer installed in a data transmission apparatus that transmits transmission target data to a plurality of data reception apparatuses is divided into (2) a plurality of blocks. Data holding means for holding data and a code relating to error detection corresponding to each block; and (3) notification information including at least the code corresponding to each block to each of the data receiving devices. And (4) a block data frame in which a block held by the data holding unit and a sequence number related to the block are inserted are generated, and the generated block data frame is transmitted to the data receiving apparatus. It is made to function as a block data frame transmission means transmitted by the broadcast communication process.

  The data reception program of the fifth aspect of the present invention corresponds to (1) a computer installed in a data reception device that receives transmission target data from the data transmission device, and (2) each of the blocks divided from the transmission target data. Notification information including a code related to error detection to be received from the data transmission device; and (3) divided from the transmission target data transmitted from the data transmission device by broadcast processing. A block data frame receiving means for receiving a block data frame in which a block and a sequence number related to the block are inserted; and (4) corresponding to each block included in the notification information notified from the data transmitting apparatus. Is inserted into each block data frame received by the block data frame receiving means. And (5) a block whose normality has been confirmed by the normality checking means, and functioning as a data restructuring means for reconstructing the transmission target data. It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, when transmitting data with respect to several data receiving device from a data transmission device, it can transmit efficiently.

It is the sequence diagram shown about operation | movement of the optical communication network system (communication system) which concerns on embodiment. It is the block diagram shown about the whole structure of the optical communication network system (communication system) which concerns on embodiment. It is the block diagram shown about the functional structure of OLT (data transmission device) which concerns on embodiment. It is the block diagram shown about the functional structure of ONU (data receiver) which concerns on embodiment. It is explanatory drawing shown about the general structure of the flame | frame which flows between OLT and ONU which concerns on embodiment. It is explanatory drawing shown about the specific structure of the flame | frame which flows between OLT and ONU which concerns on embodiment.

(A) Main Embodiments Hereinafter, embodiments of a data transmission device and program, a data reception device and program, and a communication system according to the present invention will be described in detail with reference to the drawings. Note that the communication system of the embodiment is an optical communication network system. In addition, the data transmission device and the data reception device of the embodiment are an OLT and an ONU.

(A-1) Configuration of Embodiment FIG. 2 is a block diagram showing the overall configuration of the optical communication network system 1 of this embodiment.

  In the optical communication network system 1, an OLT 10 (master station communication device) and N ONUs 20 (20-1 to 20-N) (slave station communication devices) are arranged.

  The OLT 10 and each ONU 20 are connected by an optical fiber 40 branched by an optical splitter 30 (which may be a plurality of branches). That is, the OLT 10 and each ONU 20 form a PON (GE-PON).

  In FIG. 2, the OLT 10 is connected to an upper network (master station network) not shown. Note that the configuration in which the OLT 10 is connected to an upper network (not shown) is not limited.

  On the other hand, although not shown in FIG. 2, a user network (slave station side network) is connected to each of the ONUs 20. That is, each ONU 20 is connected to a network device such as a router or a switch device of a subordinate user network. Note that a router or a switch for configuring a user network may be mounted on the ONU 20 itself.

  Next, the internal configuration of the OLT 10 and the ONU 20 will be described.

  FIG. 3 is a block diagram illustrating an example of a functional configuration of the OLT 10. FIG. 4 is a block diagram showing an example of the functional configuration of the ONU 20.

  The general hardware configuration of the OLT 10 and the ONU 20 can be the same as the system adopting the existing PON. Therefore, in FIGS. 3 and 4, the OLT corresponding to the existing GE-PON is used. And based on the general hardware configuration of the ONU. The optical communication network system 1 has a feature in processing when the OLT 10 described in the operation description section described later transmits data to be transmitted (hereinafter referred to as “transmission target data”) to the ONU 20, and the other configuration. Is not limited to the configurations of FIGS. 3 and 4, and may be of other patterns. Further, in the optical communication network system 1, processing other than processing related to transmission of data to be transmitted from the OLT 10 described later to the ONU 20 (for example, specific communication control processing between the OLT 10 and the ONU 2), for example, Processing similar to that of existing GE-PON (for example, processing conforming to IEEE 802.3ah, IEEE 802.3av, etc.) can be applied.

  Next, the internal configuration of the OLT 10 will be described with reference to FIG.

  The OLT 10 includes a control unit 11, a PON side interface 12, a LAN side interface 13, a communication processing unit 14, a data transmission unit 15, and a transmission target data storage unit 16.

  Here, for example, the OLT 10 may be constructed using an information processing apparatus having a CPU, a ROM, a RAM, and the like for executing communication processing, data processing, and the like in addition to a hardware interface unit and the like. good. Then, the OLT 10 may be constructed by installing the data transmission program or the like of the embodiment of the information processing apparatus described above. Even in that case, the functional configuration of the OLT 10 can be shown as shown in FIG.

  The control unit 11 has a function of controlling the entire OLT 10. As the control process performed by the control unit 11, other than the control process related to transmission of transmission target data to be described later (that is, the control process related to the data transmission unit 15 and the transmission target data storage unit 16), for example, the existing GE- The same processing as that of the OLT corresponding to the PON can be applied.

  The PON side interface 12 is an interface for the OLT 10 to connect to the PON (optical fiber 40). As the PON side interface 12, for example, an interface similar to the OLT corresponding to the existing GE-PON can be applied.

  The LAN side interface 13 is an interface for the OLT 10 to connect to the above-described upper side network (not shown). As long as the LAN side interface 13 is an interface corresponding to a higher-level network (not shown), its specific specification is not limited. For example, an interface similar to an OLT corresponding to an existing GE-PON (for example, 100Base) -TX, 1000Base-T, etc.) can be applied.

  The communication processing unit 14 is disposed between the PON side interface 12 and the LAN side interface 13 and has a function of performing communication processing performed by the OLT 10. Examples of communication processing performed by the communication processing unit 14 include frame transfer between the PON (each ONU 20) side and the higher-level network, communication control processing for the PON (each ONU 20) (for example, communication control processing based on MPCP, etc.) )I do. The communication processing performed by the communication processing unit 14 is, for example, an existing GE other than the communication processing related to transmission of transmission target data described later (that is, the communication processing related to the data transmission unit 15 and the transmission target data storage unit 16) A process similar to the communication process in the OLT corresponding to the PON can be applied.

  The data transmission unit 15 and the transmission target data storage unit 16 are components for transmitting transmission target data to each ONU 20. The transmission target data storage unit 16 has a function of storing data obtained by converting the transmission target data into a format to be described later. The data transmission unit 15 has a function of transmitting the contents stored in the transmission target data storage unit 16 to each ONU 20. Details of the data transmission unit 15 and the transmission target data storage unit 16 will be described later.

  Next, the internal configuration of the ONU 20 will be described with reference to FIG.

  Here, in order to simplify the description, each ONU 20 will be described as having the same configuration.

  Each ONU 20 includes a control unit 21, a PON side interface 22, a LAN side interface 23, a communication processing unit 24, and a reception data holding unit 25.

  Here, for example, the ONU 20 may be constructed using an information processing apparatus having a CPU, a ROM, a RAM, and the like for executing communication processing, data processing, and the like in addition to a hardware interface unit. good. Then, the ONU 20 may be constructed by installing the data receiving program or the like of the embodiment in the information processing apparatus described above. Even in this case, the functional configuration of the ONU 20 can be shown as shown in FIG.

  The control unit 21 has a function of controlling the entire ONU 20. The control process performed by the control unit 21 is the same as, for example, an ONU corresponding to an existing GE-PON, except for a control process related to reception of transmission target data to be described later (that is, a control process related to the data reception unit 25). Can be applied.

  The PON side interface 22 is an interface for the ONU 20 to connect to the PON (optical fiber 40). As the PON side interface 22, for example, an interface similar to an ONU corresponding to an existing GE-PON can be applied.

  The LAN side interface 23 is an interface for the ONU 20 to connect to the above-described user network (not shown). As long as the LAN side interface 23 is an interface corresponding to a user network (not shown), its specific specification is not limited. For example, an interface similar to an ONU corresponding to an existing GE-PON (for example, 1000Base-) T, 1000Base-SX, etc.) can be applied.

  The communication processing unit 24 is disposed between the PON side interface 22 and the LAN side interface 23 and has a function of performing communication processing performed by the ONU 20. Examples of the communication processing performed by the communication processing unit 24 include frame transfer between the PON (OLT 10) side and the accommodated user network, and communication control processing with the OLT 10 (for example, communication control processing related to MPCP). I do. The communication processing performed by the communication processing unit 24 is, for example, in an ONU corresponding to an existing GE-PON other than the communication processing related to reception of transmission target data described later (that is, the communication processing related to the data receiving unit 25). A process similar to the communication process can be applied.

  The data receiving unit 25 has a function of receiving transmission target data transmitted from the OLT 10. Details of the data receiving unit 25 will be described later.

  Next, the format of a frame (packet) that flows between the OLT 10 and the ONU 20 will be described.

  FIG. 5 shows a general format of a frame used in GE-PON (see Non-Patent Document 2). As for a frame flowing between the OLT 10 and the ONU 20, a frame having the same format as that shown in FIG. 5 may be applied as it is, or a frame obtained by changing a part of the format shown in FIG. May be.

  As shown in FIG. 5, the frame flowing on the GE-PON is divided into a preamble field including an LLID and an Ethernet (registered trademark) frame field. The Ethernet frame has fields of DA (destination Ethernet address), SA (source Ethernet address), type value, transmission data, and FCS (Frame Check Sequence, error detection code).

  For frames related to transmission processing of transmission target data flowing between the OLT 10 and the ONU 20 (including frames related to communication control signals), the main signal frame (the user network under the ONU 20 and the upper level connected to the OLT 10) The frame must be distinguishable from the other network). That is, the frame related to the transmission process of the transmission target data flowing between the OLT 10 and the ONU 20 needs to be in a format that can be identified as the frame related to the transmission process of the transmission target data.

  A specific method for transmitting and receiving a frame in a format in which a frame related to transmission processing of transmission target data and a frame of a main signal can be identified between the OLT 10 and the ONU 20 is not limited. Similar to the technique described in Patent Document 1, identification may be performed by applying a predetermined value to the type value field, or a dedicated LLID may be used.

  When the communication processing unit 24 of the ONU 20 recognizes the frame received from the OLT 10 as the frame related to the transmission processing of the transmission target data, the frame is supplied to the data receiving unit 25 and the frame of the main signal is received. Is transmitted from the LAN side interface 23 after performing a predetermined process. On the other hand, in the communication processing unit 14 of the OLT 10 as well, when the frame received from the ONU 20 can be recognized as the frame related to the transmission processing of the transmission target data, the frame is supplied to the data transmission unit 15, and The signal frame is transmitted from the LAN side interface 13 after performing predetermined processing. Note that the frames related to the transmission processing of the transmission target data need only be transmitted / received between the data transmitting unit 15 on the OLT 10 side and the data receiving unit 25 on the ONU 20 side, so the fields of DA and SA shown in FIG. May be omitted, or a dummy value may be set.

  In the following description, it is assumed that a communication path (communication channel) between the data transmission unit 15 of the OLT 10 and the data reception unit 25 of the ONU 20 is secured by the above configuration example.

  Next, in the optical communication network system 1, a configuration for transmitting transmission target data from the OLT 10 to the ONU 20 will be described.

  Here, data (hereinafter referred to as “software data”) of software (for example, software applied to processing of the communication processing unit 24 and the control unit 21) installed in each ONU 20 is transmitted from the OLT 10 to each ONU 20. It shall be transmitted as target data. However, the type of transmission target data transmitted from the OLT 10 to each ONU 20 is not limited to this.

  In addition, when software data is transmitted from the OLT 10 to the ONU 20, the software data is transmitted all at once to all the ONUs 20 by broadcast communication. In the existing GE-PON, there is a type of LLID called “broadcast LLID” (see Non-Patent Document 2), which is used when performing broadcast communication from the OLT to all ONUs on the PON. Also in the optical communication network system 1, transmission of software data from the OLT 10 to each ONU 20 is initially performed using this broadcast LLID.

  It is assumed that the transmission target data storage unit 16 of the OLT 10 stores in advance software data to be transmitted divided in units of block lengths to be transmitted (hereinafter referred to as “divided blocks”). Here, it is assumed that M divided blocks are formed as a result of dividing the software that is the transmission target data. Then, in the transmission target data storage unit 16, management numbers (hereinafter referred to as “sequence numbers”) are assigned to each divided block in ascending order from the first divided block, and each divided block is associated with a sequence number. It shall be managed. For example, the sequence number of the divided block from which the top portion of the software data is cut out is 1, and the sequence number of the divided block from which the last portion of the software data is cut out is M.

  The transmission target data storage unit 16 also stores data obtained by calculating a code related to error detection for confirming the normality when each divided block is received on the receiving side (ONU 20). To do. The form of the code related to error detection corresponding to each divided block is not limited, but here, CRC (Cyclic Redundancy Check) is used. That is, the transmission target data storage unit 16 also stores CRC value data based on each divided block.

  Next, a specific frame content flowing between the OLT 10 and the ONU 20 will be described.

  FIG. 6 is an explanatory diagram showing a specific configuration example of the frame flowing between the OLT 10 and the ONU 20.

  In each frame shown in FIG. 6, an LLID field is shown at the beginning, but in an actual frame, the LLID is a part included in the preamble as shown in FIG. Further, in each frame shown in FIG. 6, all the fields after the LLID indicate the contents of the “transmission data” in FIG. In each frame shown in FIG. 6, the DA, SA, type value, and FCS fields in FIG. 5 are omitted.

  FIG. 6A shows a frame (hereinafter referred to as “transmission start notification frame”) transmitted by the OLT 10 (data transmission unit 15) to each ONU 20 (data reception unit 25) prior to transmission of software data. Call).

  As shown in FIG. 6A, the transmission start notification frame is transmitted from the OLT 10 to each ONU 20 using the broadcast LLID.

  As shown in FIG. 6A, the transmission start notification frame includes a field indicating the number (M) of divided blocks of software data to be transmitted, and CRC values of all divided blocks (that is, M CRC values). ) Field is arranged. When the number of CRC values to be included in the transmission start notification frame is large and exceeds the maximum frame length, for example, only the CRC value field in the transmission start notification frame is divided into a plurality of frames and transmitted. You may make it do.

  As shown in FIG. 6A, it is assumed that the CRC value field in the transmission start notification frame is arranged in the order of sequence numbers of the corresponding divided blocks from the top. As a result, the ONU 20 (data receiving unit 25) that has received the transmission start notification frame can recognize which CRC value corresponds to which divided block.

  Each ONU 20 (data receiving unit 25) that has received the transmission start notification frame returns an ACK signal (acknowledgment response) frame to the OLT 10. Then, the OLT 10 that has received the ACK signal uses the broadcast LLID to sequentially and unilaterally transmit a frame in which software block data is inserted (hereinafter referred to as “divided block frame”) to all ONUs 20. .

  In this case, for the frame format of the ACK signal transmitted from the ONU 20 (data receiving unit 25) to the OLT 10 (data transmitting unit 15), for example, a frame having the same format as in FIG. 5 described above may be used. . Then, the ACK signal data indicating that the transmission start notification frame has been received may be set in the “transmission data” field constituting the ACK signal frame.

  FIG. 6B is an explanatory diagram showing a configuration example of a divided block frame.

  As shown in FIG. 6B, the divided block frame includes a data field of the divided block and a sequence number field of the divided block.

  FIG. 6B shows a configuration example of a divided block frame in which a divided block having a sequence number m is inserted. As described above, since the number of divided blocks of software data to be transmitted is M, the data transmitting unit 15 generates M number of divided block frames.

  Here, it is assumed that each divided block and each divided block frame have a fixed length. When dividing software data into divided blocks, the last divided block may have a shorter data length than other divided blocks. In this case, for the divided block frame in which the last divided block is inserted, for example, a portion that is shorter than other divided block frames may be supplemented with dummy data. Further, only the divided block frame in which the last divided block is inserted may be transmitted while being shorter than the other divided block frames.

  Each ONU 20 (communication processing unit 24) confirms the sequence number of the received divided block frame and calculates a CRC value based on the received divided block. Further, each ONU 20 (communication processing unit 24) collates the CRC value of each divided block received in advance with the CRC value based on the received divided block, and confirms the normality of the received divided block. Is called. Further, the ONU 20 (data receiving unit 25) reconfigures software data using the data of the divided blocks confirmed to have been received normally.

  The ONU 20 (the data receiving unit 25), when the normality confirmation by the CRC is completed up to the divided block frame of the last sequence number, the OLT 10 (the data transmitting unit) 15). In this case, for the frame format of the signal indicating the completion of download transmitted from the ONU 20 (data receiving unit 25) to the OLT 10 (data transmitting unit 15), for example, a frame having the same format as in FIG. 5 described above is used. May be. Then, data indicating that the download of the software data is completed may be set in the “transmission data” field constituting the frame of the signal.

  On the other hand, in the ONU 20 (data receiving unit 25), when there is a divided block in which an abnormality is detected during reception (error detection by CRC) or a divided block that cannot be received (hereinafter referred to as "abnormal divided block"). Records the sequence number associated with the abnormally divided block. It should be noted that the abnormal divided block may not be able to read the contents such as the sequence number or the divided block frame itself may not be received by the communication processing unit 24. Assuming such a case, for example, if the data receiving unit 25 records the sequence number of the divided block frame that has been successfully received, the sequence of the abnormal divided block is determined from the sequence number that has been skipped. The number can be grasped. Further, since the last sequence number M is clear from the transmission start notification frame, the ONU 20 (data receiving unit 25) can also detect that the last divided block frame has not been received normally.

  The processing method in which the ONU 20 (data receiving unit 25) reconstructs software data from the received divided blocks is not limited. For example, each time the ONU 20 (data receiving unit 25) receives one divided block and confirms normality, the ONU 20 sequentially develops it in a memory (not shown) for storing software data, as in the technique described in Patent Document 1. Thus, the working memory may be saved. When the ONU 20 (data receiving unit 25) detects an abnormal divided block, the ONU 20 (the data receiving unit 25) keeps an area in which the divided block is to be stored in the above-described memory, and continues memory development of the subsequent divided blocks. You may do it. Then, the ONU 20 (data receiving unit 25) may expand the data of the divided block acquired later by a retransmission request described later for the memory area that is made free by detecting the abnormal divided block. Further, the ONU 20 (data receiving unit 25), for example, merges and reconfigures all after confirming the normality of all the divided blocks, and then expands them in the above-mentioned memory (not shown). Also good.

  When the ONU 20 (data receiving unit 25) detects an abnormal divided block in the process of receiving the divided block frame, the ONU 20 (data receiving unit 25) requests a frame for requesting retransmission of the divided block having the sequence number corresponding to the abnormal divided block (hereinafter, referred to as an ONU 20). "Retransmission request frame") is transmitted to the OLT 10 (data transmission unit 15).

  FIG. 6C is an explanatory diagram showing a configuration example of a retransmission request frame.

  As shown in FIG. 6C, a list of sequence numbers (sequence numbers that the data receiving unit 25 needs to request retransmission) related to the abnormal division block is inserted in the retransmission request frame.

  Then, in the OLT 10 (data transmission unit 15) that has received the retransmission request frame, the transmission source ONU 20 is identified from the LLID of the retransmission request frame, and the divided block related to the retransmission request frame is inserted only for the identified ONU 20. Frame (hereinafter referred to as “retransmission divided block frame”) is transmitted using unicast LLID. That is, the LLID included in the retransmission divided block frame is not a broadcast LLID but an LLID related to the transmission destination ONU 20.

  FIG. 6D is an explanatory diagram showing a configuration example of a retransmission divided block frame.

  As shown in FIG. 6D, the retransmission divided block frame has the same configuration as the divided block frame except for the LLID to be used. The sequence number field of the divided block to be retransmitted and the data of the divided block data to be retransmitted are the same. Field. FIG. 6D shows a case where data of the mth divided block is retransmitted.

  Each time the ONU 20 (data receiving unit 25) receives the retransmission divided block frame, the ONU 20 checks the sequence number of the received retransmission divided block frame and calculates the CRC value, as in the case of the divided block frame. The normality is confirmed by collating with the CRC value of the corresponding divided block received in advance. When the normality of the divided block of the received retransmission divided block frame is confirmed, the ONU 20 (data receiving unit 25) transmits an ACK signal frame indicating that to the OLT 10 (data transmitting unit 15). .

  In this case, for the frame format of the ACK signal transmitted from the ONU 20 (data receiving unit 25) to the OLT 10 (data transmitting unit 15), for example, a frame having the same format as in FIG. 5 described above may be used. . Then, the ACK signal data (which may include the corresponding sequence number) indicating that the retransmission divided block frame has been received is set in the field of “transmission data” constituting the ACK signal frame. May be.

  On the other hand, when the retransmission divided block frame cannot be normally received (for example, when it cannot be received or when the result of error detection by CRC is abnormal), the ONU 20 (data receiving unit 25) Furthermore, a retransmission request frame for retransmitting the divided block may be transmitted to the OLT 10 (data transmission unit 15), or may be abnormally terminated as a download failure. Further, an upper limit of the number of times of retransmission request frame transmission may be set in the ONU 20 (data reception unit 25), and the retransmission request frame transmission may be repeated up to the upper limit number of times.

  When the OLT 10 (data transmission unit 15) receives the frame of the ACK signal corresponding to the transmitted retransmission divided block frame from the ONU 20 (data reception unit 25), the contents of the retransmission request frame received from the ONU 20 (data reception unit 25) ( Check the list of sequence numbers. Then, if there is a next sequence number in the list of sequence numbers included in the retransmission request frame, the OLT 10 (data transmission unit 15) selects the sequence number. Then, the OLT 10 (data transmission unit 15) transmits the retransmission divided block frame in which the divided block corresponding to the selected sequence number is inserted. In this way, the OLT 10 (data transmission unit 15) retransmits the divided blocks related to all sequence numbers requested in the retransmission request frame received from the ONU 20 (data reception unit 25).

  On the other hand, when the ONU 20 (data receiving unit 25) normally receives all the retransmission divided block frames requested by the retransmission request frame, the ONU 20 reconfigures the software data using the retransmitted divided blocks, and further, the software data A signal frame indicating the end of download (may be a frame having the same format as described above) is notified to the OLT 10.

(A-2) Operation | movement of embodiment Next, operation | movement of transmission object data (software data) transmission in the optical communication network system 1 of this embodiment which has the above structures is demonstrated.

  Here, it is assumed that data of divided blocks of software data to be transmitted and data of CRC values corresponding to the respective divided blocks are registered in advance in the transmission target data storage unit 16. Note that the process of generating the divided block and the CRC value from the software data may be performed by an external device, or may be performed by the data transmission unit 15 (timing is not limited).

  In addition, the transmission target data storage unit 16 registers divided blocks and CRC values corresponding to a plurality of software data, and those corresponding to the software data specified by the setting or operation by the user are stored in the OLT 10 (data transmission Part 15). Further, the trigger for transmitting the software data from the OLT 10 (data transmission unit 15) to each ONU 20 is not limited. For example, the software data may be started at a timing according to a user operation or setting.

  FIG. 1 is a sequence diagram showing an example of processing for transmitting software data from the OLT 10 to each ONU 20 in the optical communication network system 1.

  In FIG. 1, only the ONUs 20-1 and 20 -N out of the ONUs 20-1 to 20 -N are illustrated, and other operations of the ONU 20 are omitted for the sake of simplicity.

  When software data transmission processing is started in the OLT 10 (data transmission unit 15), a transmission start notification frame is transmitted from the OLT 10 (data transmission unit 15) to each ONU 20 using the broadcast LLID (S101).

  When receiving the transmission start notification frame, each ONU 20 transmits a frame of an ACK signal indicating that the transmission start notification frame has been received to the OLT 10 (data transmission unit 15) using the unicast LLID (S102). . Note that in the OLT 10 (data transmission unit 15), when there is an ONU 20 that has not responded with an ACK signal for a predetermined time or more, for example, a transmission start notification frame may be transmitted only for the ONU 20 or a broadcast LLID. The transmission start notification frame may be retransmitted using. The OLT 10 (data transmission unit 15) may transmit a transmission start notification frame from the beginning with a unicast LLID and accept a response of an ACK signal from the ONU 20 (data reception unit 25).

  Then, the OLT 10 (data transmission unit 15) transmits M divided block frames (sequence numbers: 1 to M) to each ONU 20 using the broadcast LLID. In each ONU 20 that has received the divided block frame, the sequence number of the received divided block frame is confirmed and the CRC value is calculated. Further, the ONU 20 is verified by checking with the CRC value of each divided block received in advance. Sexuality is also confirmed (S103).

  Here, as shown in FIG. 1, it is assumed that the ONU 20-1 has normally received all the divided block frames. On the other hand, in the ONU 20-N, only the divided block frame with the sequence number “4” is detected as an error as a result of error detection by CRC, and software data cannot be reconfigured. In this case, the data receiving unit 25 of the ONU 20-N records that the sequence number “4” was an abnormally divided block.

  Then, from the data receiving unit 25 of the ONU 20-1 that has been normally received for all the divided block frames, a signal frame indicating the end of downloading of the software data is transmitted to the OLT 10 to the OLT 10 (data transmitting unit 15). (S104). Further, the data receiving unit 25 of the ONU 20-1 performs software data reconfiguration processing based on the divided blocks inserted in the received divided block frame.

  On the other hand, the data receiving unit 25 of the ONU 20-N generates a retransmission request frame for requesting retransmission of the divided block detected as the abnormal divided block (the divided block corresponding to the sequence number “4”), and the OLT 10 (data The data is transmitted to the transmission unit 15) (S105).

  When the retransmission request frame is received from the ONU 20-N, the OLT 10 (data transmission unit 15) stores the divided block corresponding to the sequence number “4” based on the list of sequence numbers included in the retransmission request frame. Read from the unit 16. Then, the OLT 10 (data transmission unit 15) transmits the retransmitted divided block frame into which the read divided block is inserted, to the ONU 20-N using a unicast LLID (S106).

  When the retransmission division block frame is received, the data reception unit 25 of the ONU 20-N confirms the sequence number of the received retransmission division block frame, calculates the CRC value, and further receives each division received in advance. Normality is also checked by collating with the CRC value of the block (S107). In this example, it is assumed that the data reception unit 25 of the ONU 20-N has normally received the divided block inserted in the received retransmission divided block frame. As a result, the ONU 20-N has successfully received all the data of the divided blocks constituting the software data, so that the entire software data can be reconfigured.

  Then, a frame of a signal indicating the end of downloading of software data is transmitted from the data reception unit 25 of the ONU 20-N that has been normally received for all the divided block frames to the OLT 10 (data transmission unit 15) (S108). Also on the (data transmission unit 15) side, it is possible to grasp that the transmission of software data has been normally completed for all the ONUs 20.

  As described above, software data is transmitted from the OLT 10 to each ONU 20.

(A-3) Effects of Embodiment According to this embodiment, the following effects can be achieved.

  In this embodiment, the “transmission start notification frame” and the “divided block frame” are transmitted from the OLT 10 to each ONU 20 using the broadcast LLID. As a result, it is not necessary to individually transmit software data to each ONU 20, so that the PON bandwidth and the resources on the OLT 10 side can be used efficiently.

  In this embodiment, a transmission start notification frame (CRC value corresponding to each divided block) is transmitted from the OLT 10 to each ONU 20, and the ONU 20 side receives in advance the normality of the divided block received thereafter. Confirmed using CRC value. Furthermore, each ONU 20 requests the OLT 10 to retransmit an abnormal divided block that could not be normally received, and individually receives a retransmission from the OLT 10 by unicast. That is, in this embodiment, only the divided blocks that could not be normally received by each ONU 20 are retransmitted from the OLT 10 by unicast, so the optical communication network system 1 reliably uses resources efficiently. Software data can be transmitted.

  In particular, when the size of the software data to be transmitted is large, or when the load of the ONU 20 is already high when the software data is received, an error in the ONU 20 that has received the divided block frame (for example, the processing of the CPU is in time). In some cases, the received divided block frame may not be processed normally due to an error such as no data or data loss. Therefore, in such a case, the above-described retransmission request processing is effective.

(B) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(B-1) In the above embodiment, the OLT 10 and the ONU 20 have been described as supporting GE-PON. However, the OLT 10 and the ONU 20 have a configuration capable of performing broadcast communication from the OLT to each ONU using a broadcast LLID or the like. It can also be applied to other PON systems. The “LLID” in the above embodiment is an EPON (Ethernet Passive Optical Network) defined in IEEE 802.3ah (Ethernet (registered trademark) in the First Mile), but is used to identify a logical link. It may be replaced with one having a field and a mechanism for broadcasting on a logical link.

(B-2) In the above embodiment, in order to check the normality of the divided block on the receiving side (ONU 20), the CRC value is used as a code related to error detection. However, the divided block is used on the receiving side (ONU 20). The code related to error detection used for checking the normality of the code is not limited to the CRC value. For example, a code related to error detection other than CRC (for example, a method using a checksum or hash function) may be applied to the optical communication network system 1. Further, as a code related to error detection, a code that performs correction as well as error detection (for example, a Hamming code, FEC (Forward Error Correction) code, etc.) may be applied. In the optical communication network system 1, when an error correction code is applied as a code related to error detection, the reception side (ONU 20) may detect a division block that cannot be corrected as an abnormal division block. good.

(B-3) In the above embodiment, the example in which data is transmitted from the OLT (data transmission apparatus) to the ONU (data reception apparatus) in the GE-PON has been described. However, the present invention is applicable to the data transmission apparatus and the data reception apparatus of the present invention. The type of device to be used and the corresponding communication method are not limited. For example, a server device or a network device (for example, a network device (for example, a network configured by an L2 / L3 switch, a router, or the like) using a LAN interface (for example, 100Base-TX, 1000Base-T, or the like) as a data transmission device (for example, , A router constituting a network on the telecommunications carrier side, etc.) may be applied. In addition, as a data receiving device, a client terminal (for example, a personal computer) connected to the data transmitting device via a LAN or a lower-level network device (for example, a router on the subscriber side connected to a telecommunications carrier facility) is applied. You may make it do. In this case, for broadcast communication from the data transmission device to the data reception device, communication using a broadcast IP address, a broadcast MAC address, a multicast IP address, or the like may be applied instead of the broadcast LLID. .

  DESCRIPTION OF SYMBOLS 1 ... Optical communication network system (communication system), 10 ... OLT (data transmission device), 11 ... Control part, 12 ... PON side interface, 13 ... LAN side interface, 14 ... Communication processing part, 15 ... Data transmission part, 16 Transmission target data storage unit 20, 20-1 to 20-N ONU (data receiving device) 21 Control unit 22 PON side interface 23 LAN side interface 24 Communication processing unit 25 Data Receiving part, 30 ... optical splitter, 40 ... optical fiber.

Claims (7)

In a communication system comprising a plurality of data receiving devices and a data transmitting device that transmits data to be transmitted to the receiving communication device,
The data transmission device is
Data holding means for holding data obtained by dividing the transmission target data into a plurality of blocks and a code related to error detection corresponding to each block;
Notification means for transmitting notification information including at least the code corresponding to each block to each of the data receiving devices;
A block data frame for generating a block data frame in which a block held by the data holding means and a sequence number related to the block are inserted, and transmitting the generated block data frame to the data receiving apparatus by broadcast processing Transmission means,
Each of the above data receiving devices
Notification receiving means for receiving notification information from the data transmitting device;
Block data frame receiving means for receiving a block data frame transmitted from the data transmission device by broadcast communication processing;
Using the code corresponding to each block included in the notification information notified from the data transmitting device, the normality of the block inserted in each block data frame received by the block data frame receiving means is checked. Normality testing means;
A data reconfiguring unit that reconstructs the transmission target data using a block whose normality has been confirmed by the normality inspecting unit. Each of the above data receiving devices
For the block in which the abnormality is detected by the normality checking unit, the block further includes a retransmission request unit that requests retransmission to the data transmission device,
The data transmission device is
When there is a retransmission request from any of the above data receiving apparatuses, a block data frame in which a block related to the retransmission request and a sequence number related to the block are inserted is generated, and the data receiving apparatus that is a retransmission request source The communication system according to claim 1, further comprising block data retransmission means for transmitting. The notification information notified by the notification means includes information on the number of blocks constituting the transmission target data,
The retransmission request means uses the information on the number of blocks included in the notification information notified from the data transmitting apparatus and the contents received by the block data frame receiving means to determine the blocks constituting the transmission target data. 3. The communication system according to claim 2, wherein a block that has not been received by the block data frame receiving unit is detected, and the block that has not been received is also requested to be retransmitted to the data transmission device. In a data transmission device that transmits data to be transmitted to a plurality of data reception devices,
Data holding means for holding data obtained by dividing the transmission target data into a plurality of blocks and a code related to error detection corresponding to each block;
Notification means for transmitting notification information including at least the code corresponding to each block to each of the data receiving devices;
A block data frame for generating a block data frame in which a block held by the data holding means and a sequence number related to the block are inserted, and transmitting the generated block data frame to the data receiving apparatus by broadcast processing And a data transmission device. In the data receiving device that receives the transmission target data from the data transmitting device,
Notification receiving means for receiving, from the data transmitting apparatus, notification information including a code related to error detection corresponding to each of the blocks divided from the transmission target data;
Block data frame receiving means for receiving a block data frame transmitted from the data transmitting apparatus, which is transmitted by broadcast processing, and into which a block divided from the transmission target data and a sequence number related to the block are inserted;
Using the code corresponding to each block included in the notification information notified from the data transmitting device, the normality of the block inserted in each block data frame received by the block data frame receiving means is checked. Normality testing means;
A data receiving device comprising: data reconstructing means for reconstructing the transmission target data using a block whose normality has been confirmed by the normality examining means. A computer mounted on a data transmission device that transmits data to be transmitted to a plurality of data reception devices,
Data holding means for holding data obtained by dividing the transmission target data into a plurality of blocks and a code related to error detection corresponding to each block;
Notification means for transmitting notification information including at least the code corresponding to each block to each of the data receiving devices;
A block data frame for generating a block data frame in which a block held by the data holding means and a sequence number related to the block are inserted, and transmitting the generated block data frame to the data receiving apparatus by broadcast processing A data transmission program which functions as a transmission means. A computer mounted on a data receiving device that receives data to be transmitted from the data transmitting device,
Notification receiving means for receiving, from the data transmitting apparatus, notification information including a code related to error detection corresponding to each of the blocks divided from the transmission target data;
Block data frame receiving means for receiving a block data frame transmitted from the data transmitting apparatus, which is transmitted by broadcast processing, and into which a block divided from the transmission target data and a sequence number related to the block are inserted;
Using the code corresponding to each block included in the notification information notified from the data transmitting device, the normality of the block inserted in each block data frame received by the block data frame receiving means is checked. Normality testing means;
A data reception program that functions as data reconstruction means for reconstructing the transmission target data using a block whose normality has been confirmed by the normality inspection means.

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