JP4932024B2 - Multipoint control processing circuit and method - Google Patents

Description

  In a point-multipoint communication system composed of a master station and a plurality of slave stations, the present invention assigns a unique identifier to each slave station, and between the master station and each slave station according to this identifier. The present invention relates to a multipoint control processing circuit and method for performing multipoint control processing of frames to be transmitted and received.

  For example, an OLT (Optical Line Terminal: optical subscriber line termination device) serving as a master station of a PON (Passive Optical Network) system and a plurality of ONUs (Optical Network Unit: optical subscriber line network devices) serving as slave stations In an MPCP (Multi-point Control Protocol) processing circuit that controls communication between the ONUs, this is applied to allocation control of a unique identifier (LLID: Logical Link IDentifier) for each ONU.

FIG. 1 shows a configuration example of a PON system (Non-Patent Documents 1 and 2).
In FIG. 1, a PON system includes an OLT 101 installed in a station, a plurality of m ONUs 102 installed in each user's house, an optical fiber 103 and an optical fiber that connect the OLT 101 and the plurality of m ONUs 102 to 1: m. And a splitter 104. An external network 105 is connected to the OLT 101.

  In the PON system, upstream signals transmitted from a plurality of ONUs 102 are bundled by the optical splitter 104 and reach the OLT 101. Therefore, IEEE 802.3 and IEEE 802.3av define MPCP for controlling the timing at which each ONU transmits an upstream signal so that the upstream signal does not collide with each other.

  In this MPCP rule, the OLT assigns a unique identifier LLID to each ONU, identifies each ONU using this LLID, and performs communication. For example, when the OLT transmits a downlink frame to a specific ONU, the LLID assigned to the ONU is assigned to the downlink frame, and the downlink frame is transmitted to all ONUs. The ONU determines whether or not it is a downlink frame transmitted to itself based on the LLID assigned to the received downlink frame, and determines whether or not to receive. Conversely, when an ONU transmits an uplink frame to the OLT, the ONU transmits an uplink frame with an LLID assigned to the ONU, and the OLT transmits the uplink frame with the LLID assigned to the received uplink frame. Determine ONU.

  The OLT periodically performs a discovery process based on MPCP, assigns an LLID to a new ONU, and establishes a connection. Here, an overview of the Discovery process will be described with reference to FIG. The following (1) to (7) correspond to the MPCP frames shown in FIG.

(1) The OLT transmits a Discovery Gate frame to all ONUs. In this Discovery Gate frame, the local time t1 of the OLT, the time T1 when the new ONU can start outputting the upstream frame, and an identifier (broadcast LLID) that clearly indicates that the frame is for all ONUs are described.

(2) When the ONU that has not established a link with the OLT receives the Discovery Gate frame, it sets t1 described in the Discovery Gate frame to its own local time and synchronizes the time with the OLT. Then, after a random time from the time T1 specified in the Discovery Gate frame, a Registration Request frame is transmitted to the OLT to request registration. At this time, since the LLID is not assigned to the ONU, the broadcast LLID is described as an identifier in the Register Request frame.

(3) The OLT assigns a unique LLID to the ONU that has transmitted the Register Request frame, and transmits the Register frame to notify the assigned LLID to the ONU.

(4) Subsequently, the OLT transmits a Gate frame describing the transmission start time T2 of the next frame to the ONU, and waits for the arrival of the Register ACK frame.

(5) When the ONU receives the Register frame and the Gate frame, the ONU transmits a Register ACK frame at the transmission start time T2 specified by the Gate frame. When the OLT receives a Register ACK frame from the ONU, a link between the OLT and the ONU is established. This is the Discovery process.

(6) The OLT that has established a link with the ONU transmits a Gate frame in which the transmission start time T3 of the upstream signal of the ONU is described.

(7) When the ONU receives the Gate frame, it waits for transmission until the transmission start time T3 specified in the ONU, calculates the amount of frames waiting for transmission during that time, and when it reaches the transmission start time T3, the Report frame To notify the OLT of the transmission frame amount.

  The OLT assembles the order of transmission start times for each ONU according to the transmission frame amount and bandwidth allocation algorithm (DBA: Dynamic Bandwidth Allocation) notified from each ONU in the Report frame, and sequentially transmits the Gate frame toward the ONU. . When the ONU receives the Gate frame, the ONU transmits an uplink frame during a period specified by the Gate frame, and also transmits a Report frame for receiving the next Gate frame. The OLT and the ONU repeat communication according to the above procedure. When the OLT cannot receive the frame described above from the ONU for a certain period, it determines a timeout and disconnects from the ONU.

FIG. 3 shows a configuration example of the OLT.
In FIG. 3, the OLT includes a PON side transmission / reception circuit 11, a reception processing circuit 12, an MPCP processing circuit 13, a bridge circuit 14, an external network side transmission / reception circuit 15, and a transmission processing circuit 16.

  The upstream frame from the ONU is input to the PON side transmission / reception circuit 11, converted from an optical signal to an electrical signal, and output to the reception processing circuit 12. The reception processing circuit 12 sorts the input frame into an MPCP frame and a user frame. Here, the MPCP frame is a general term for control frames for realizing MPCP in the PON system, and the user frame indicates a frame other than the MPCP frame. The user frame is output to the bridge circuit 14 and output from the external network side transmission / reception circuit 15 to the external network.

  On the other hand, the MPCP frame is input from the reception processing circuit 12 to the MPCP processing circuit 13. The MPCP processing circuit 13 monitors the connection with each ONU by LLID, and outputs an MPCP frame to be transmitted to each ONU to the transmission processing circuit 16 as necessary. The transmission processing circuit 16 time-division-multiplexes the user frame input from the external network and the MPCP frame input from the MPCP processing circuit 13 and outputs the result to the PON side transmission / reception circuit 11. The PON-side transmission / reception circuit 11 converts the input downstream frame from an electrical signal to an optical signal and transmits it to the ONU.

  By the way, the OLT assigns a 16-bit LLID to each ONU and performs communication. However, since the number of ONUs connected to the OLT is about several tens to several hundreds, each LLID is converted into a several-bit ID in the apparatus. Generally, each frame is processed based on this ID. For example, when the number of connected ONUs is m, numbers consecutive to 0, 1, 2,..., M−1 are IDs corresponding to each ONU, and m is an ID for broadcast LLID (hereinafter, broadcast ID). Called).

  In the OLT, the MPCP processing circuit 13 manages the association between the LLID and the ID and notifies each unit of the correspondence. For example, the MPCP processing circuit 13 notifies the reception processing circuit 12 of the LLID and ID of the next frame to be received. In the reception processing circuit 12, if the LLID of the input frame matches the LLID input from the MPCP processing circuit 13, the ID input at the same time is written in the received frame, and the bridge circuit 14 or the MPCP processing circuit 13 is written. Output to. Further, the MPCP processing circuit 13 notifies the bridge circuit 14 of the connected ONU's MAC address and ID as ONU registration information. The bridge circuit 14 identifies the destination ONU of the frame from the destination MAC address of the user frame input from the external network side transmission / reception circuit 15, assigns an ID for the corresponding ONU, and outputs it to the transmission processing circuit 16. The ID / LLID conversion information is input to the transmission processing circuit 16 from the MPCP processing circuit 13, the LLID is calculated from the ID of the input frame, the LLID is added to the frame, and is output to the PON side transmission / reception circuit 11. .

FIG. 4 shows a configuration example of a conventional MPCP processing circuit.
4, a conventional MPCP processing circuit 13b includes a reception memory control unit 131b, a reception frame storage memory 132b, a control unit 133b including an MPCP processing program, a time management unit 134, a bandwidth control unit 135, an ID / LLID register 136, a transmission The frame storage memory 137 and the transmission memory control unit 138 are configured.

  The MPCP frame from the reception processing circuit 12 is input to the reception memory control unit 131b. The reception memory control unit 131b calculates a write address to the reception frame storage memory 132b from the LLID described in the received MPCP frame, and writes the received MPCP frame to the address.

  FIG. 5 shows a configuration example of the reception frame storage memory 132b in the conventional MPCP processing circuit 13b. The received frame storage memory 132b is a unicast frame storage area (address is 0 to m-1) for storing MPCP frames from ONUs to which LLIDs are assigned, and broadcast for storing frames from ONUs to which LLIDs are not assigned. It consists of a frame storage area (address from m to 2m-1).

  The unicast frame storage area corresponds to the LLID whose address is assigned to each ONU. The MPCP frame from the ONU to which the LLID is assigned is written with the corresponding ID (0 to m−1) by the reception processing circuit 12 and input to the reception memory control unit 131b. When the ID assigned to the received MPCP frame is 0 to m−1, the reception memory control unit 131b writes the received frame at an address corresponding to the value.

  On the other hand, a Register Request frame from an ONU to which no LLID is assigned has a broadcast ID (m) described in the reception processing circuit 12 and is input to the reception memory control unit 131b. When the ID assigned to the received MPCP frame is m, the reception memory control unit 131b writes the received frame in the broadcast frame storage area of the reception frame storage memory 132b. Here, it is assumed that the reception memory control unit 131b writes the received broadcast frames in order from the address m. For example, when broadcast frames are continuously received from two ONUs, the received frames are written at addresses m and m + 1 as shown in FIG. Since the ONU that has transmitted the Register Request frame to which the broadcast ID is assigned is assigned the LLID and ID by the control unit 133b, the MPCP frame received from the ONU that is received next is stored in the unicast frame storage area. Will be written. When the writing to the reception frame storage memory 132b is completed, the reception memory control unit 131b notifies the control unit 133b that the frame has been written.

  The control unit 133b reads the MPCP frame in accordance with the MPCP processing program, performs MPCP control with the ONU, and assigns LLID and ID. The control unit 133b writes the correspondence relationship between the LLID and the ID in the ID / LLID register 136 and notifies the time management unit 134 of the connection state with the ONU as link information. The time management unit 134 manages the local time of the OLT, determines a timeout for connection with each ONU as necessary, and notifies the control unit of it. Further, the control unit 133b notifies the bandwidth control unit 135 of the connection state of the ONU and the transmission frame amount notified by the Report frame as link information. The bandwidth control unit 135 implements a bandwidth update algorithm (DBA), assembles the transmission start time of each ONU based on the link information from the control unit 133b, and issues a gate frame transmission instruction to the control unit 133b. The control unit 133b performs an MPCP frame transmission process based on the MPCP processing program and an instruction from the bandwidth control unit 135. In the MPCP frame transmission process, the MPCP frame transmitted by the control unit 133b is written in the transmission frame storage memory 137, and a message to that effect is output to the transmission memory control unit 138.

  FIG. 6 shows a configuration example of the transmission frame storage memory 137 in the conventional MPCP processing circuit 13b. The transmission frame storage memory 137 is composed of storage areas with addresses from 0 to m, and each address corresponds to an ID assigned to a frame to be transmitted. When notified that the MPCP frame has been written in the transmission frame storage memory 137, the transmission memory control unit 138 reads the MPCP frame and outputs it to the transmission processing circuit 16.

  In the MPCP processing circuit 13b, the control unit 133b, the band control unit 135, and the ID / LLID register 136 output information regarding the correspondence between the LLID and the ID to each unit of the OLT. First, the control unit 133b outputs to the bridge circuit 14 registration information of the ONU that has newly established a connection. This registration information includes an ID assigned to the ONU. The bandwidth control unit 135 stores the transmission start time transmitted to each ONU, and outputs the LLID and ID of the ONU that next receives the frame to the reception processing circuit 12. The ID / LLID register 136 outputs ID and LLID conversion information to the transmission processing circuit 16.

FIG. 7 shows an example of the processing procedure of the MPCP processing program.
In FIG. 7, when this program is started, an event generation wait state is entered (S0). In the MPCP processing circuit 13b, three types of events occur: reception, transmission, and timeout. When an event occurs, this program verifies whether or not the generated event is a reception event by a reception notification from the reception memory control unit 131b (S1). If it is a reception event, the process shifts to reception event processing (S2), and when the processing ends, the process returns to waiting for an event (S0). If it is not a reception event, it is verified whether the generated event is a transmission event according to a transmission instruction from the bandwidth control unit 135 (S3). If it is a transmission event, the process proceeds to a transmission event process (S4), and when the process is completed, the process waits for an event to occur (S0). If it is not a transmission event, the program determines that the event has occurred as a timeout event from the time management unit 134, and proceeds to timeout event processing (S5). When the timeout event processing ends, the process returns to waiting for an event to occur (S0).

FIG. 8 shows an example of the procedure of the conventional reception event processing S2 in the MPCP processing program.
In FIG. 8, when a reception event occurs, the received frame is read from the received frame storage memory 132b (S20), and it is verified whether or not the ID described in the frame is a broadcast ID (S21). In the case of a broadcast ID, an unused ID is searched (S22), one of the unused IDs is selected and an ID is assigned to the ONU (S23). When the ID assignment is completed, the process proceeds to a link state control process for realizing MPCP defined in IEEE 802.3 and IEEE 802.3av (S24). If the ID described in the read frame is other than the broadcast ID, the process immediately shifts to the link state control process (S24). In this link state control process, this program allocates / releases LLID, updates LLID and ID in association with LLID, outputs link information to bandwidth control unit 135, and outputs to bridge circuit 14 as necessary. The ONU registration information is output and the link information to the time management unit 134 is output.

  When the link state control process ends, it is verified whether there is a frame to be transmitted to the ONU based on the result of the link state control process (S25). If there is a frame to be transmitted, the frame to be transmitted is written in the transmission frame storage memory (S26), and a transmission preparation completion notification is output to the transmission memory control unit 138 (S27). When the frame transmission is completed or there is no frame to be transmitted, it is verified whether or not the connection with the ONU is disconnected based on the result of the link state control process (S28). When disconnecting, the ID / LLID register 136 is cleared, and disconnection processing for notifying the band control unit 135, the time management unit 134, and the bridge circuit 14 that the connection has been disconnected is performed (S29). When the above disconnection process ends or the connection is not disconnected, the process of the reception event ends.

FIG. 9 shows an example of the procedure of the conventional transmission event processing S4 in the MPCP processing program.
In FIG. 9, when a transmission event occurs, a frame to be transmitted is written to the transmission frame storage memory 137 (S40), and when the writing is completed, a transmission preparation completion notification is output to the transmission memory control unit 138 (S41).

FIG. 10 shows an example of the procedure of conventional timeout event processing S5 in the MPCP processing program.
In FIG. 10, when a timeout event occurs, the process proceeds to link state control processing (S50). When the link state control process ends, it is verified whether there is a frame to be transmitted to the ONU based on the result of the link state control process (S51). If there is a frame to be transmitted, the frame to be transmitted is written in the transmission frame storage memory 137 (S52), and a transmission preparation completion notification is output to the transmission memory control unit 138 (S53). If the frame transmission is completed or there is no frame to be transmitted, it is verified whether or not the connection with the ONU is disconnected based on the result of the link state control process (S54). When disconnecting, the ID / LLID register 136 is cleared, and disconnection processing for notifying the bandwidth control unit 135, the time management unit 134, and the bridge circuit 14 that the connection has been disconnected is performed (S55). When the above disconnection process ends or the connection is not disconnected, the timeout event process ends.

IEEE Std 802.3-2005: Part 3: Carrier sense multiple access with collision detection (CSMA / CD) access method and physical layer specifications IEEE Std 802.3avTM -2009: Part3: Carrier Sense Multiple Access with Collision Detection (CSMA / CD) Access Method and Physical Layer Specifications

  In the conventional configuration, areas for storing frames of broadcast IDs are prepared as many as the total number of ONUs that can be registered as the maximum value. That is, the capacity of the broadcast ID frame is required by the MPCP frame length × the total number of ONUs. For this reason, the total capacity of the received frame storage memory 132b needs to be twice the capacity (MPCP frame length × total number of ONUs) for storing unicast ID frames, which increases the circuit scale of the MPCP processing circuit 13b. It was. This is because an ID is not determined when the reception memory control unit 131b writes a broadcast ID frame in the reception frame storage memory 132b because the MPCP processing program performs ID allocation.

  According to the present invention, the receiving memory control unit assigns an unused ID to an ONU frame to which no ID is assigned, so that an area for storing a broadcast ID frame is not provided in the receiving frame storage memory, and the circuit scale is reduced. An object of the present invention is to provide a multipoint control processing circuit and method that can be reduced.

  In the first invention, a master station assigns a unique identifier to each slave station between a master station and a plurality of slave stations connected in a one-to-many manner, and the master station and each slave station are assigned according to this identifier. When performing multipoint control processing of frames transmitted / received between, the ID is assigned corresponding to the identifier of each slave station, and between the master station and each slave station based on an ID having a smaller number of bits than that identifier In a multipoint control processing circuit that performs multipoint control processing of frames to be transmitted and received, received frame storage means for storing a frame received from a slave station in a storage area corresponding to the ID, and an ID corresponding to the number of slave stations ID management means for managing information indicating whether it is completed or unused, and a frame received from the slave station to which the ID is assigned is stored in a storage area corresponding to the ID of the received frame storage means, and the ID is assigned. One of unused IDs managed by the ID management unit is selected and assigned to a frame received from a slave station that has not been stored, and stored in a storage area corresponding to the ID of the received frame storage unit, and ID management A reception memory control means for setting the ID as used for the means, a slave station to which an ID has already been assigned, and a frame received from a slave station to which an unused ID has been assigned by the reception memory control means. And multipoint control means for setting the ID management means to make the ID unused when the connection with the slave station is disconnected.

The reception frame storage means has a storage area corresponding to the number of slave stations as a storage area of a frame corresponding to the ID.
The ID management means is configured to manage whether the ID is used or unused with 1-bit information.

  According to a second aspect of the present invention, a master station assigns a unique identifier to each slave station between a master station and a plurality of slave stations connected in a one-to-many manner, and the master station and each slave station are assigned according to this identifier. When performing multipoint control processing of frames transmitted / received between, the ID is assigned corresponding to the identifier of each slave station, and between the master station and each slave station based on an ID having a smaller number of bits than that identifier In a multipoint control processing method for performing multipoint control processing of a frame to be transmitted / received, a received frame storage means of a master station stores a frame received from a slave station in a storage area corresponding to the ID, and ID management means of the master station Manages the information indicating whether the ID corresponding to the number of slave stations is used or not, and stores the frame in the received frame storage means. The reception memory control means stores the frame received from the slave station to which the ID is assigned. Receive fr Storing one of the unused IDs managed by the ID management unit for the frame received from the slave station to which the ID is not allocated, The multipoint control means for storing the ID in the storage area corresponding to the ID of the reception frame storage means, setting the ID to the ID management means as used, and performing the multipoint control processing is already assigned an ID. When a frame received from a slave station to which an unused ID is assigned by the slave station and the reception memory control means, multipoint control processing is performed based on the ID, and when the connection with the slave station is disconnected, ID management means Is set to make the ID unused.

The received frame storage means has a storage area corresponding to the number of slave stations as a storage area of the frame corresponding to the ID.
The ID management means manages whether the ID is used or not with 1-bit information.

  In the multipoint control processing circuit and method of the present invention, the received frame storage means only needs to have an area for storing frames received from all the slave stations (all ONUs) connectable to the master station (OLT), and can be assigned an ID. An area for storing a frame of a broadcast ID received from a slave station (ONU) that is not required becomes unnecessary, and the necessary capacity can be substantially halved compared to the conventional configuration. Also, ID assignment processing can be easily performed using the reception memory control means and ID management means, and the amount of software processing can be reduced. Thereby, the circuit scale, power consumption, and cost of the multipoint control processing circuit can be reduced.

It is a figure which shows the structural example of a PON system. It is a figure explaining the outline | summary of a Discovery process. It is a figure which shows the structural example of OLT. It is a figure which shows the structural example of the conventional MPCP processing circuit. It is a figure which shows the structural example of the receiving frame memory | storage memory 132b in the conventional MPCP processing circuit 13b. It is a figure which shows the structural example of the transmission frame memory | storage memory 137 in the conventional MPCP processing circuit 13b. It is a flowchart which shows an example of the process sequence of a MPCP process program. It is a flowchart which shows an example of the procedure of the conventional reception event process S2 in a MPCP process program. It is a flowchart which shows an example of the procedure of the conventional transmission event process S4 in a MPCP process program. It is a flowchart which shows an example of the procedure of the conventional timeout event process S5 in a MPCP process program. It is a figure which shows the Example structure of the multipoint control processing circuit of this invention. It is a figure which shows the structural example of the receiving frame memory | storage memory 132a and the ID register | resistor 139. It is a figure which shows the example of storage of the receiving frame memory 132a and ID register 139. It is a flowchart which shows an example of the procedure of the reception event process S2 of this invention in a MPCP process program. It is a flowchart which shows an example of the procedure of the timeout event process S5 of this invention in a MPCP process program.

  FIG. 11 shows an embodiment of the multipoint control processing circuit of the present invention. Here, the MPCP processing circuit provided in the OLT of the PON system will be described as an example of the multipoint control processing circuit.

  11, the MPCP processing circuit 13a of this embodiment includes a reception memory control unit 131a, a reception frame storage memory 132a, a control unit 133a including an MPCP processing program, a time management unit 134, a bandwidth control unit 135, and an ID / LLID register 136. , A transmission frame storage memory 137, a transmission memory control unit 138, and an ID register 139. 4 is different from the conventional MPCP processing circuit 13b shown in FIG. 4 in that the ID register 139 is added and the functions of the MPCP processing program installed in the reception memory control unit 131a, the reception frame storage memory 132a, and the control unit 133a are different.

  The received frame storage means corresponds to the received frame storage memory 132a, the ID management means corresponds to the ID register 139, the received memory control means corresponds to the reception memory control unit 131a, and the multipoint control means corresponds to the control unit 133a.

FIG. 12 shows a configuration example of the reception frame storage memory 132a and the ID register 139.
In FIG. 12, the reception frame storage memory 132a has a configuration in which the broadcast frame storage area is deleted from the conventional reception frame storage memory 132b shown in FIG. That is, the address is composed of storage areas from 0 to m-1, and each address corresponds to the ID of the received frame. The ID register 139 is composed of a storage device with addresses from 0 to m-1. Each address of the ID register 139 corresponds to an ID assigned to each ONU, and information on whether each ID is used or not is stored. The ID register 139 outputs an unused ID to the reception memory control unit 131a. Then, the reception memory control unit 131a sets a used ID, and the control unit 133a clears (unuses) the used ID according to the instruction of the MPCP processing program.

  In the present invention, the reception memory control unit 131a assigns an ID to an ONU to which no ID is assigned. When receiving a Register Request frame from an ONU to which no ID is assigned, the reception memory control unit 131a selects one unused ID output from the ID register 139 and sets it as an ID assigned to the ONU. Then, the reception memory control unit 131a writes the received Register Request frame to the address of the reception frame storage memory 132a corresponding to the allocated ID, and outputs an ID set signal indicating that the ID allocated to the ID register 139 is used. To do.

  For example, when the MPCP processing circuit 13a of the present invention continuously receives broadcast ID frames from two ONUs, unused IDs 0 and 1 are assigned as IDs as shown in FIG. The received frame is written to addresses 0 and 1 of 132a, and used information is set to addresses 0 and 1 of the ID register 139. The above example is an example in the case where the reception memory control unit 131a assigns an unused ID to an unused ID, and it goes without saying that any ID may be assigned from the unused ID.

  Note that the LLID is assigned to the frame assigned the ID from the reception memory control unit 131a by the MPCP processing program of the control unit 133a.

  The processing procedure of the MPCP processing program installed in the control unit 133a of the MPCP processing circuit 13a of the present invention is the same as that shown in FIG. However, the contents of the reception event process S2 are different from the contents of the timeout event process S5. The transmission event process S4 is the same as the prior art shown in FIG.

  FIG. 14 shows an example of the procedure of the reception event processing S2 of the present invention in the MPCP processing program. The conventional reception event processing procedure shown in FIG. 8 is that broadcast ID verification (S21), unused ID search (S22), ID allocation (S23) are deleted, and ID register clear (S30) is added.

  When a reception event occurs, the received frame is read from the reception frame storage memory 132a (S20), and the process immediately proceeds to link state control processing (S24). In this link state control process, this program allocates / releases LLID, updates LLID and ID in association with LLID, outputs link information to bandwidth control unit 135, and outputs to bridge circuit 14 as necessary. The ONU registration information is output and the link information to the time management unit 134 is output.

  When the link state control process ends, it is verified whether there is a frame to be transmitted to the ONU based on the result of the link state control process (S25). If there is a frame to be transmitted, the frame to be transmitted is written in the transmission frame storage memory 137 (S26), and a transmission preparation completion notification is output to the transmission memory control unit 138 (S27). When the frame transmission is completed or there is no frame to be transmitted, it is verified whether or not the connection with the ONU is disconnected based on the result of the link state control process (S28). When disconnecting, the ID / LLID register 136 is cleared, and disconnection processing for notifying the band control unit 135, the time management unit 134, and the bridge circuit 14 that the connection has been disconnected is performed (S29). Then, a clear signal of the ID is output to the ID register 139, and the ID of the ONU is made unused (S30). When the above disconnection process ends or the connection is not disconnected, the process of the reception event is ended.

  FIG. 15 shows an example of the procedure of the timeout event processing S5 of the present invention in the MPCP processing program. ID register clear (S56) is added after the disconnection process (S55) of the conventional timeout event process shown in FIG. The clearing of the ID register 139 is the same process as the clearing of the ID register (S30) in the reception processing event shown in FIG.

  In the reception frame storage memory 132a of the MPCP processing circuit 13a of this embodiment, the broadcast frame storage area required for the conventional reception frame storage memory 132b is not necessary, and the necessary capacity can be substantially halved. However, although the ID register 139 is newly required, the MPCP frame is stored in the broadcast frame storage area of the reception frame storage memory 132a, whereas each ID is used or unused in the ID register 139. Is stored, and the amount of memory can be greatly reduced. Thereby, the circuit scale, power consumption, and cost of the MPCP processing circuit can be reduced.

  Also in the control unit 133a of the MPCP processing circuit 13a, software processing such as verification of broadcast ID (S21), unused ID search (S22), and ID allocation (S23) in the reception event processing S2 shown in FIG. This can be handled by hardware using the ID register 139. This is because, in the conventional configuration, the hardware could not know whether or not the ID has been used, but in the present invention, information is notified to the hardware by the ID register 139. As a result, the amount of software processing can be reduced, and stable operation performance can be improved, power consumption can be reduced, and processor costs can be reduced.

  Note that the software processing that is no longer necessary according to the present invention, that is, processing corresponding to broadcast ID verification (S21), unused ID search (S22), and ID allocation (S23) in reception event processing S2 Since this is performed by the reception memory control unit 131a, the circuit scale of the reception memory control unit 131a is larger than the conventional one. However, since these processes can be realized by a simple combinational circuit, it is sufficiently smaller than the broadcast ID storage area that can be reduced by the present invention, and the circuit can be reduced in size compared to the conventional one.

  The present invention can be implemented even when the upstream speed of the connected ONU is 1 Gbps (IEEE802.3) or 10 Gbps (IEEE802.3av). However, the configuration is not limited to this, and any configuration that can store a frame in the same memory area as an ONU to which an ID has already been assigned when an MPCP frame in which a broadcast ID is described is received. For example, an ONU with an uplink speed of 1 Gbps and an ONU with 10 Gbps may be mixed.

  In this embodiment, the PON system has been described as an example. However, the configuration of the present invention is not limited to this, and the master station that controls communication is an identifier unique to the slave station connected to the master station. Can be applied to a point-multipoint communication system in which communication is performed by allocating.

DESCRIPTION OF SYMBOLS 11 PON side transmission / reception circuit 12 Reception processing circuit 13 MPCP processing circuit 14 Bridge circuit 15 External network side transmission / reception circuit 16 Transmission processing circuit 13a, 13b MPCP processing circuit 131a, 131b Reception memory control part 132a, 132b Reception frame storage memory 133a, 133b Control Section 134 Time management section 135 Band control section 136 ID / LLID register 137 Transmission frame storage memory 138 Transmission memory control section 139 ID register

Claims (6)

A frame in which the master station assigns a unique identifier to each slave station between the master station and the plurality of slave stations connected in a one-to-many relationship, and is transmitted and received between the master station and each slave station according to this identifier. When performing the multipoint control process, a frame that is allocated corresponding to the identifier of each slave station and is transmitted and received between the master station and each slave station based on an ID having a smaller number of bits than the identifier. In the multipoint control processing circuit that performs multipoint control processing of
Received frame storage means for storing the frame received from the slave station in a storage area corresponding to the ID;
ID management means for managing information indicating whether the ID corresponding to the number of slave stations is used or unused;
The frame received from the slave station to which the ID is assigned is stored in a storage area corresponding to the ID of the received frame storage means, and the frame received from the slave station to which the ID is not assigned is Select and assign one unused ID managed by the ID management means, store it in the storage area corresponding to the ID of the received frame storage means, and make the ID used for the ID management means A reception memory control means to be set;
For the slave station to which the ID is already assigned and the frame received from the slave station to which the unused ID is assigned by the reception memory control means, the multipoint control processing is performed based on the ID, and the slave station and A multipoint control processing circuit comprising: a multipoint control unit configured to set the ID management unit to make the ID unused when the connection is disconnected. The multipoint control processing circuit according to claim 1,
The multipoint control processing circuit, wherein the received frame storage means has a storage area corresponding to the number of slave stations as a storage area of the frame corresponding to the ID. The multipoint control processing circuit according to claim 1,
The multipoint control processing circuit, wherein the ID management means manages whether the ID is used or not by using 1-bit information. A frame in which the master station assigns a unique identifier to each slave station between the master station and the plurality of slave stations connected in a one-to-many relationship, and is transmitted and received between the master station and each slave station according to this identifier. When performing the multipoint control process, a frame that is allocated corresponding to the identifier of each slave station and is transmitted and received between the master station and each slave station based on an ID having a smaller number of bits than the identifier. In the multipoint control processing method of performing multipoint control processing of
The received frame storage means of the master station stores the frame received from the slave station in a storage area corresponding to the ID,
The ID management means of the master station manages information indicating whether the ID corresponding to the number of slave stations is used or unused,
Receiving a memory control means for storing the frame to the receiving frame memory means to store the frame received from the slave station to the ID is allocated to the storage area corresponding to the ID of the received frame storage means, said ID Is selected and assigned to one of the unused IDs managed by the ID management means for the frame received from the slave station to which no ID is assigned, and is stored in the storage area corresponding to the ID of the received frame storage means And store the ID to the ID management means as used,
The multipoint control means for performing the multipoint control processing is based on the ID of the slave station to which the ID is already assigned and the frame received from the slave station to which the unused ID is assigned by the reception memory control means. The multipoint control processing method is characterized in that the multipoint control processing is performed, and when the connection with the slave station is disconnected, the ID management means is set to make the ID unused. The multipoint control processing method according to claim 4, wherein
The received frame storage means has a storage area corresponding to the number of slave stations as a storage area of the frame corresponding to the ID. The multipoint control processing method according to claim 4, wherein
The multi-point control processing method, wherein the ID management means manages whether the ID is used or not with 1-bit information.

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