JP7314674B2 - PON system and communication equipment - Google Patents

Description

The present invention relates to a PON system and communication device.

2. Description of the Related Art In recent years, in order to meet demands such as cost reduction and diversification of communication equipment, it has been studied to modularize the communication functions of communication equipment using software.
Specifically, instead of customizing the hardware parts of communication equipment, virtualization is being considered that leaves the minimum communication functions in the hardware parts and allows the application parts of other communication equipment to execute functions such as functions for specific business operators and functions that require frequent updates.

Patent Literatures 1 and 2 describe, as part of the above virtualization, a communication device that executes a DBA (Dynamic Bandwidth Allocation) function of an OLT (Optical Line Terminal) that configures a PON (Passive Optical Network) system by an application component that runs on an OS (Operating System).
Non-Patent Literatures 1 and 2 define requirements for the function or performance of an API (Application Programming Interface) when a DBA with strict time constraints is used as an application component.

JP 2018-074467 A WO2019/017427

BBF (Broadband Forum) TR-402 Functional Model for PON Abstraction Interface, Issue: 1.0, Issue Date: October 2018 BBF (Broadband Forum) TR-403 PON Abstraction Interface Specifications, Issue: 1.0, Issue Date: October 2018

As in Patent Documents 1 and 2, when part of the PON functions are migrated to application components, the more functions that are migrated, the more versatile and compact the hardware configuration of the OLT (such as the hardware 310 in FIG. 1 of Patent Document 2) can be compared to conventional products.
Therefore, by connecting OLTs having a plurality of hardware configurations and communication devices having application components to a concentrator, it is possible to configure an OLT aggregate type station-side terminal device in which a plurality of OLTs are integrated in the housing of the concentrator.

In this manner, in a configuration in which an OLT having a hardware configuration and another communication device having an application component are connected to a concentrator, it is necessary to implement an accelerator for transmitting/receiving a function frame (for example, a DBA control frame to be described later) containing function information required for the PON function to/from the communication device in the FPGA of the OLT or the like.
In this case, as the number of PON functions to be softwareized in other communication devices increases, the types of function frames handled by the OLT also increase. Therefore, depending on the size of the FPGA of the OLT, it may not be possible to add a new accelerator, and it may not be possible to follow the addition of functions in the future.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to address such conventional problems and to flexibly cope with the future addition of functions without changing the hardware configuration of the station-side terminating equipment.

(1) A system according to an aspect of the present invention is an optical communication system comprising one or more station-side terminating devices that terminate corresponding PON lines, and a concentrator to which the station-side terminating devices are directly or indirectly connected, wherein target devices directly or indirectly connected to the concentrator include the following first and second communication devices. 2 communication device: a communication device that executes predetermined software

(9) A device according to an aspect of the present embodiment is a communication device that is directly or indirectly connected to a concentrator to which one or more station-side terminating devices that terminate corresponding PON lines are directly or indirectly connected, and comprises: a housing; a transmitting/receiving unit that receives a grant control frame defined below from and transmits it to the station-side terminating device; a report processing unit that converts the received report into the batch report and inputs it to the transmitting/receiving unit; and a gate processing unit that converts the received batch gate into the grant control frame and inputs it to the transmitting/receiving unit.

Report: Control frame in which only one requested transmission amount of the subscriber-side terminating device is stored Batch report: Control frame in which the requested transmission amount of the subscriber-side terminating device is stored collectively Batch gate: Control frame in which grant information of the subscriber-side terminating device is collectively stored Grant control frame: Control frame in which only one grant information of the subscriber-side terminating device is stored

(10) A device according to another aspect of the present embodiment is a communication device that is directly or indirectly connected to a concentrator to which one or more station-side terminating devices that terminate corresponding PON lines are directly or indirectly connected, and comprises: a housing; from the other communication device and transmits a sleep control frame defined below to the station-side terminating device; a bandwidth notification processing unit that converts the received bandwidth notification into the collective bandwidth notification and inputs it to the transmission/reception unit; and a PS processing unit that converts the received collective PS notification into the sleep control frame and inputs it to the transmission/reception unit.

Bandwidth notification: A control frame that stores only one piece of bandwidth information for a subscriber-side terminating device Batch bandwidth notification: A control frame that collectively stores bandwidth information for a subscriber-side terminating device Batch PS notification: A control frame that collectively stores sleep information for a subscriber-side terminating device Sleep control frame: A control frame that stores only one piece of sleep information for a subscriber-side terminating device

The present invention can be realized not only as a system and apparatus having the above-described characteristic configuration, but also as a program for causing a computer to execute such a characteristic configuration.
Also, the present invention can be implemented as a semiconductor integrated circuit that implements part or all of the system and device.

According to the present invention, future addition of functions can be flexibly accommodated without changing the hardware configuration of the station-side terminal device.

1 is a block diagram showing an example of the overall configuration of an optical communication system; FIG. It is a block diagram which shows an example of an internal structure of a general-purpose server. 1 is a schematic diagram showing an example of a connection form (topology) of an optical communication system in which a plurality of small OLTs are connected to one concentrator; FIG. FIG. 10 is a block diagram showing an example (comparative example 1) of an optical communication system in which an application component migrated to a general-purpose server is a DBA application; FIG. 11 is a block diagram showing an example (comparative example 2) of an optical communication system in which application components migrated to a general-purpose server are a DBA application and a power saving application; 1 is a block diagram showing an implementation example (implementation example 1) of an optical communication system having a communication module for DBA; FIG. FIG. 7 is a block diagram showing an implementation example (implementation example 2) of an optical communication system in which a power saving communication module is added to the implementation example 1 of FIG. 6 ; FIG. 8 is a block diagram showing an implementation example (implementation example 3) of an optical communication system in which another communication module is added to the implementation example 2 of FIG. 7 ; 3 is a block diagram showing an example of transfer control in a concentrator; FIG. 2 is a block diagram showing an example of the internal configuration of a small OLT; FIG. 2 is a block diagram showing a circuit configuration example of an FPGA in an FPGA-type communication module (for DBA); FIG. 2 is a block diagram showing a circuit configuration example of an FPGA in an FPGA-type communication module (for power saving); FIG. 2 is a block diagram showing an example of the internal configuration of a CPU-type communication module; FIG. FIG. 4 is a sequence diagram showing the procedure of DBA processing in an optical communication system; FIG. 11 is a block diagram showing a modification of the optical communication system;

<Overview of Embodiments of the Present Invention>
Hereinafter, the outline of the embodiments of the present invention will be listed and described.

(1) The PON system of this embodiment is an optical communication system comprising one or more station-side terminating devices that terminate corresponding PON lines, and a line concentrator to which the station-side terminating devices are directly or indirectly connected.
First communication device: A communication device having a hardware-configured accelerator that communicates with a second communication device using a communication frame containing information necessary for executing predetermined software Second communication device: A communication device that executes predetermined software

According to the PON system of this embodiment, the station-side terminating device that terminates the corresponding PON line is connected to the concentrator, and the target devices directly or indirectly connected to the concentrator include the above-mentioned first communication device.
Therefore, it is possible to obtain an optical communication system that can flexibly cope with the addition of functions in the future without changing the hardware configuration of the station-side terminating equipment.

(2) In the PON system of this embodiment, it is preferable that the station-side terminal device and the first communication device are pluggable modules that are directly connected to the concentrator.
In this case, a communication frame (for example, a DBA report, a grant control frame, etc.) used for communication between the station-side terminal device and the first communication device is transmitted and received within the concentrator. Therefore, compared to the case where at least one of the station-side terminating device and the first communication device is indirectly connected to the concentrator, the execution speed of the software by the second communication device can be increased.

(3) In the PON system of the present embodiment, it is preferable that the first communication device and the second communication device are pluggable modules directly connected to the concentrator.
In this case, communication frames (for example, DBA control frames, power saving control frames, etc.) used for communication between the first communication device and the second communication device are transmitted and received within the concentrator. Therefore, compared to the case where at least one of the first terminating device and the second communication device is indirectly connected to the concentrator, the execution speed of software by the second communication device can be increased.

(4) In the PON system of the present embodiment, the software includes an application component for realizing a part of the PON function, and a common function unit connected to the application component via an internal API. Preferably, the accelerator is composed of an FPGA that communicates with the common function unit using a functional frame for transmitting function information required for the part of the function.

According to the PON system of the present embodiment, the accelerator of the first communication device is configured by the FPGA that communicates with the common function unit of the second communication device by means of functional frames for transmitting function information necessary for part of the PON functions.
Therefore, it is possible to obtain an optical communication system that can flexibly cope with the future addition of PON functions without changing the hardware configuration of the station-side terminal device.

(5) In the PON system of the present embodiment, the application component preferably includes a DBA application for realizing a DBA function for one or more subscriber-side terminating devices accommodated in the PON line.
In this case, since the second communication device executes the DBA application, the second communication device can substitute the DBA function for the station-side terminal device connected to the concentrator.

(6) In the PON system of the present embodiment, the application component preferably includes a power saving application for realizing a power saving function for one or more subscriber-side terminal devices accommodated in the PON line.
In this case, since the second communication device executes the power saving application, the second communication device can substitute the power saving function for the central terminal device connected to the concentrator.

(7) In the PON system of the present embodiment, it is preferable that the software includes an application component for realizing a predetermined service based on the user data transmitted by the subscriber-side terminal device accommodated in the PON line, and the accelerator is configured by an FPGA that executes determination processing required for the service using the user data and notifies the second communication device of the determination result.

According to the PON system of the present embodiment, the accelerator of the first communication device uses user data to perform determination processing necessary for the service, and is composed of an FPGA that notifies the second communication device of the determination result.
Therefore, edge computing that reduces the processing load of the second communication device can be easily realized without changing the hardware configuration of the station-side terminal device.

(8) In the PON system of the present embodiment, it is preferable that the user data is image data output by a monitoring camera connected to the subscriber-side terminal device, the application component includes a security application for notifying the user of monitoring results, and the determination process is a process of determining the state of a predetermined object included in the image data.
In this case, the accelerator of the first communication device executes processing for determining the state of the predetermined object included in the image data and notifies the second communication device of the determination result, so the second communication device does not need to execute the determination processing. Therefore, the processing load on the second communication device can be reduced.

(9) A communication device of the present embodiment is a communication device directly or indirectly connected to a concentrator to which one or a plurality of station-side terminating devices that terminate corresponding PON lines are directly or indirectly connected, and comprises a housing and a hardware-configured accelerator accommodated in the housing, wherein the accelerator receives a report defined below from the station-side terminating device, transmits a batch report defined below to another communication device, and receives a batch gate defined below from the other communication device. a transmission/reception unit for transmitting a grant control frame defined below to the station-side terminating device; a report processing unit for converting the received report into the batch report and inputting it to the transmission/reception unit; and a gate processing unit for converting the received batch gate into the grant control frame and inputting it to the transmission/reception unit.

Report: Control frame in which only one requested transmission amount of the subscriber-side terminating device is stored Batch report: Control frame in which the requested transmission amount of the subscriber-side terminating device is stored collectively Batch gate: Control frame in which grant information of the subscriber-side terminating device is collectively stored Grant control frame: Control frame in which only one grant information of the subscriber-side terminating device is stored

According to the communication device of this embodiment, the report processing unit converts the received report into a batch report and inputs it to the transmission/reception unit, and the gate processing unit converts the received batch gate into a grant control frame and inputs it into the transmission/reception unit. Therefore, it is not necessary to mount an accelerator for conversion processing of batch reports and batch gates in the station-side terminating equipment.
Therefore, the hardware configuration of the station-side terminating device can be simplified and fixed, and the generalization of the station-side terminating device can be promoted.

(10) A communication device according to the present embodiment is a communication device directly or indirectly connected to a concentrator to which one or a plurality of station-side terminating devices that terminate corresponding PON lines are directly or indirectly connected, and comprises: a housing; a transmission/reception unit that receives from a communication device and transmits a sleep control frame defined below to the station-side terminating device; a bandwidth notification processing unit that converts the received bandwidth notification into the collective bandwidth notification and inputs it to the transmission/reception unit;

Bandwidth notification: A control frame that stores only one piece of bandwidth information for a subscriber-side terminating device Batch bandwidth notification: A control frame that collectively stores bandwidth information for a subscriber-side terminating device Batch PS notification: A control frame that collectively stores sleep information for a subscriber-side terminating device Sleep control frame: A control frame that stores only one piece of sleep information for a subscriber-side terminating device

According to the communication device of this embodiment, the bandwidth notification processing unit converts the received bandwidth notification into a batch bandwidth notification and inputs it to the transmission/reception unit, and the PS processing unit converts the received batch PS notification into a sleep control frame and inputs it to the transmission/reception unit. Therefore, it is not necessary to mount an accelerator for conversion processing of batch band notification and batch PS notification in the station-side terminating device.
Therefore, the hardware configuration of the station-side terminating device can be simplified and fixed, and the generalization of the station-side terminating device can be promoted.

<Details of the embodiment of the present invention>
Hereinafter, details of embodiments of the present invention will be described with reference to the drawings. At least part of the embodiments described below may be combined arbitrarily.

[Overall Configuration of Optical Communication System]
FIG. 1 is a schematic diagram showing an example of the overall configuration of an optical communication system.
As shown in FIG. 1, the optical communication system of this embodiment is a PON system including a station-side terminal device 1, a subscriber-side terminal device 2, a concentrator 3, a general-purpose server 4, a host device 5, and the like.
The concentrator 3 may be connected to communication devices other than the station-side terminal device 1, the general-purpose server 4, and the host device 5 (for example, the communication modules 6A and 7A in FIG. 6).

In this embodiment, the PON is assumed to be a PON (eg, GE-PON or 10GE-PON) conforming to IEEE communication standards.
However, the PON may be a PON (eg, G-PON, XG-PON, XGS-PON, NG-PON2, etc.) complying with ITU-T communication standards.

The station-side terminating equipment 1 consists of an optical line terminating equipment on the upper side of the PON line. The subscriber side terminating equipment 2 consists of an optical line terminating equipment on the lower side of the PON line.
A station-side terminating device 1 is installed, for example, in a station building of a telecommunications carrier, together with a concentrator 3, a general-purpose server 4, and a host device 5. FIG. The subscriber-side terminating device 2 is installed in the home of the subscriber of the communication service. Note that the general-purpose server 4 may be communicably connected to the station-side terminal device 1 via an optical line or the like, and may be installed in a remote location outside the station building.

A PON line is a tree-structured optical line in which an optical fiber is branched by an optical coupler. The station-side terminating device 1 is connected to the trunk fiber of the PON line, and the subscriber-side terminating device 2 is connected to the branch fiber of the PON line.
Hereinafter, the station-side terminal device 1 of the PON line is referred to as "OLT1", and the subscriber-side terminal device 2 of the PON line is referred to as "ONU2".

The line concentrator 3 is composed of, for example, an L2 switch. The line concentrator 3 determines a physical port for transmitting the received communication frame according to the destination, source, type, and the like of the communication frame.
For example, in the case of the optical communication system of FIG. 1, the line concentrator 3 allows the physical port of the OLT 1 to communicate with the physical port of the host device 5 for communication frames of the main signal system such as user frames. The concentrator 3 communicates the physical port of the OLT 1 with the physical port of the general-purpose server 4 for control frames.

The general-purpose server 4 is composed of a personal computer (PC) on which an OS such as Linux (registered trademark) is installed. The general-purpose server 4 functions as a communication device for executing user management and service settings related to PON communication between the OLT 1 and ONU 2 by communicating with the OLT 1 via a predetermined communication line (for example, a LAN cable).
The host device 5 is a communication device connected to a host network (not shown). The host device 5 is composed of, for example, an edge router.

In the optical communication system of FIG. 1, part of the OLT functions are transferred to the general-purpose server 4 by replacing some of the PON functions executed by the conventional OLT hardware components with software components executed by the CPU (Central Processing Unit) of the general-purpose server 4.
The more functions related to PON communication transferred to the general-purpose server 4, the more general-purpose and miniaturized the OLT 1 can be compared with conventional products. For example, the OLT 1 of this embodiment is composed of an optical communication device downsized to an SFP (Small Form-factor Pluggable) module. Therefore, hereinafter, the OLT 1 is also referred to as "small OLT 1".

FIG. 1 illustrates a case where the functions (software components) transferred to the general-purpose server 4 are DBA (Dynamic Bandwidth Allocation) and OAM (Operation Administration and Maintenance).
Since DBA is a function for dynamically allocating an upstream band of a PON line, it influences the QoS (Quality of Service) of PON communication. Therefore, if the DBA is migrated to the general-purpose server 4, it becomes possible to flexibly change or add the contents of the DBA such as QoS simply by correcting or adding software components related to the DBA.

When migrating the DBA and OAM functions to the general-purpose server 4, the control frames sent and received between the OLT 1 and the general-purpose server 4 include parameter setting information for user management and service settings, as well as OAM messages and DBA band information with a common information format.
In addition, when the functions transferred to the general-purpose server 4 are DBA and OAM, other functions required for PON communication such as MPCP (Multi Point Control Protocol), encryption, and VLAN (Virtual LAN) remain as functions to be executed by hardware components such as FPGA (Field-Programmable Gate Array) of OLT 1.

The function related to PON communication transferred to the general-purpose server 4 may be at least one function executed by the conventional OLT hardware component, and is not limited to DBA and OAM. For example, the functions related to PON communication transferred to the general-purpose server 4 may include a power saving function for sleep control of the ONU 2, a registration and authentication function for the ONU 2, and the like.
It should be noted that the transfer destination of functions related to PON communication may be not only the general-purpose server 4 but also other communication devices (for example, the communication module 7A in FIG. 6) connected to the line concentrator 3 .

[Hardware configuration of general-purpose server]
FIG. 2 is a block diagram showing an example of the internal configuration of the general-purpose server 4. As shown in FIG.
As shown in FIG. 2 , the general-purpose server 4 of this embodiment includes a housing 40 , and a control unit 41 , a storage unit 42 and a communication unit 43 accommodated in the housing 40 . An operation unit 44 and a display unit 45 are connected to the housing 40 of the general-purpose server 4 .

The control unit 41 , the storage unit 42 and the communication unit 43 are attached to the back plane inside the housing 40 . The operation unit 44 and the display unit 45 are connected to predetermined connectors of the backplane, respectively. The control unit 41 controls operations of the hardware units 42 to 45 .
The control unit 41 is composed of an arithmetic processing unit including a CPU and a main memory composed of a RAM (Random Access Memory). The CPU of the control unit 41 reads a computer program (software) 46 installed in the storage unit 42 into the main memory, and performs various information processing according to the program 46 .

The storage unit 42 includes a recording medium made of at least one non-volatile memory of HDD (Hard Disk Drive) and SSD (Solid State Drive), and an auxiliary storage device including at least one of an external or built-in optical drive.
The communication unit 43 includes a communication card (for example, a LAN card) that performs Ethernet (registered trademark) communication with an external device. The communication unit 43 is connected to the line concentrator 3 through a predetermined communication cable such as a LAN cable.

The operation unit 44 includes input devices such as a keyboard and pointing device. The operator of the telecommunications carrier can send a predetermined command (for example, a control command to the OLT setting unit 52, the switch control unit 53, etc.) to the control unit 41 of the general-purpose server 4 by inputting a command or performing an operation such as clicking on the operation unit 44.
The display unit 45 is composed of a display device such as a liquid crystal monitor or an organic EL panel. The display unit 45 can display a GUI (Graphical User Interface) screen or the like for receiving an operation input to the operation unit 44 .

In the general-purpose server 4 of FIG. 2, the operation unit 44 and the display unit 45 used by the operator do not necessarily have to be directly connected to the housing 40 of the general-purpose server 4 itself.
For example, if the OS 47 or the middleware section 48 of the general-purpose server 4 has a remote control function, it is sufficient to log in to the general-purpose server 4 from another PC distant from the general-purpose server 4 and perform a predetermined operation input using the operation section 44 and display section 45 of the PC.

[Software configuration of general-purpose server]
As shown in FIG. 2, a computer program (software) 46 read from the storage unit 42 and executed by the CPU of the control unit 41 includes a middleware unit 48 that operates on the OS 47, one or more application components 49, an internal API 50, an external API 51, an OLT setting unit 52, and a switch control unit 53. The application component 49 is created based on the internal API 50 , and the middleware section 48 is created based on the internal API 50 and the external API 51 . The OLT setting unit 52 is created based on the external API 54 and the switch control unit 53 is created based on the external API 55 . In addition, in this embodiment, an "application" may be abbreviated as an "application."

The above computer program 46 can be distributed as a software product by storing it in a removable recording medium such as a USB memory in addition to the recording medium constituting the storage unit 42 of the general-purpose server 4 .
The computer program 46 can also be distributed as a software product through a public communication network such as the Internet. Note that when the computer program 46 is stored in the general-purpose server 4 via a USB memory or network, the general-purpose server 4 does not necessarily need to be provided with an optical drive.

In the following, a situation in which the operability of the application component 49 depends on at least one difference between the type (including version) of the communication standard to which the communication device such as the OLT 1 conforms and the manufacturing vendor is referred to as "device dependence."
Conversely, a situation in which the operability of the application component 49 does not depend on the type (including version) of the communication standard to which the communication equipment such as the OLT 1 conforms and the difference between the manufacturing vendors is referred to as "equipment independence."

The middleware unit 48 is software that absorbs differences in software and/or hardware below the application component 49 by providing the internal API 50 to the application component 49 .
The application component 49 is a generalized software component that can be replaced by the internal API 50 . A software component is a piece of software in which necessary functions are grouped in replaceable units.

In FIG. 2, as the application components 49, a DBA application 49A, a power saving application 49B, and an OAM application 49C are illustrated.
The DBA application 49A is an application component for realizing the DBA function of dynamically allocating the upstream band of the ONU2. The power saving application 49B is an application component for implementing a power saving function that controls the ONU 2 to sleep. The OAM application 49C is an application component for implementing OAM functions between OLT1/ONU2.

The internal API 50 is a device-independent input/output interface. The application components 49A-49C are connected to the middleware section 48 via internal APIs 50A-50C defined respectively for the application components 49A-49C.
Therefore, the middleware unit 48 inputs and outputs predetermined information to the application components 49A-40C using the internal APIs 50A-50C.

The external API 51 is a device-dependent input/output interface. The middleware unit 48 is connected to hardware components of an external communication device (for example, FPGA of OLT 1, etc.) via external APIs 51A to 51C defined respectively for application components 49A to 49C.
Therefore, the middleware section 48 inputs and outputs predetermined information to and from the hardware components of the external communication device by means of the external APIs 51A to 51C.

The information format of the external API 51 is standardized for each of the application components 49A-49C. The external API 51 includes control frames such as "function frames".
The function frame is a control frame for transmitting function information (requested transmission amount and grant information in the case of DBA) required to execute some functions of the PON function. Therefore, the external API 51A for the DBA application 49A includes "Bulk Report" and "Bulk Gate". Hereinafter, the collective report and collective gate are collectively referred to as "DBA control frame".

A collective report is a functional frame in which the upstream transmission request amount of at least one ONU 2 accommodated in one PON line is collectively stored.
The middleware unit 48 inputs the upstream transmission request amount of each ONU 2 described in the batch report received by the communication unit 43 from the OLT 1 to the DBA application 49A via the internal API 50A. The DBA application 49A executes a predetermined DBA algorithm using the input transmission request amount of each ONU 2 as a variable, and calculates grant information (transmission start time and transmission time length) to be assigned to each ONU 2 for each LLID (Logical Link ID).

A collective gate is a function frame in which grant information of at least one ONU 2 accommodated in one PON line is collectively stored.
The DBA application 49A outputs the calculated grant information for each LLID assigned to each ONU 2 to the middleware unit 48 via the internal API 50A. The middleware unit 48 generates a bulk gate addressed to the OLT 1 including the grant information for each input LLID, and causes the communication unit 43 to transmit the generated bulk gate.

The external API 51B for the power saving application 49B includes "batch band notification" and "batch PS (Power Save) notification". Hereinafter, collective band notification and collective PS notification are collectively referred to as "power saving control frame".

The collective bandwidth notification is a functional frame in which the user data transmission amount (bandwidth information) per unit time of at least one ONU 2 accommodated in one PON line is collectively stored.
The middleware unit 48 inputs the user data transmission amount described in the batch band notification received by the communication unit 43 from the OLT 1 to the power saving application 49B via the internal API 50B. The power saving application 49B executes a predetermined power saving algorithm using the input user data transmission amount of each ONU 2 as a variable, and calculates sleep information (sleep start time and sleep period) of each ONU 2 for each LLID.

A collective PS notification is a functional frame in which sleep information of at least one ONU 2 accommodated in one PON line is collectively stored.
The power saving application 49B outputs the calculated sleep information for each LLID of each ONU 2 to the middleware section 48 via the internal API 50B. The middleware unit 48 generates a collective PS notification addressed to the OLT 1 including the sleep information for each LLID input, and causes the communication unit 43 to transmit the generated collective PS notification.

The OLT setting unit 52 is a management software component for realizing various settings related to PON communication, such as parameter setting for the OLT 1 and acquisition of registration information of the ONUs 2 accommodated in the OLT 1 .
The external API 54 is at least one of device-dependent and device-independent input/output interfaces that connect the OLT setting unit 52 of the general-purpose server 4 and hardware components of the OLT 1 (for example, FPGA of the OLT 1).

As the OLT setting unit 52, for example, VOLTHA (Virtual OLT Hardware Abstraction) provided by ONF (Open Networking Foundation) or software conforming to a predetermined communication protocol such as Netconf/YANG can be adopted.
However, the OLT setting unit 52 of the present embodiment is software that conforms to VOLTHA, which has many device-independent external APIs 54 and is highly versatile.

The external API 54 includes control frames such as "configuration frames". The setting frame is a control frame for transmitting setting information necessary for setting the PON. Since the OLT setting unit 52 of the present embodiment is software conforming to VOLTHA, the setting frame is also referred to as "VOLTHA frame".
The setting information to be included in the VOLTHA frame includes, for example, the number of accommodated ONUs, the LLID value of registered ONUs, correspondence information between the LLID value and the value of the identifier (hereinafter referred to as "VID") written in the VLAN tag, and user information for each LLID.

The switch control unit 53 is a software component that communicates with the line concentrator 3 according to a predetermined communication protocol, and implements setting of transfer rules by the line concentrator 3 and the like.
The external API 55 is at least one of device-dependent and device-independent input/output interfaces that connect the switch control unit 53 of the general-purpose server 4 and the line concentrator 3 .

As the switch control unit 53, for example, OpenFlow (registered trademark) provided by ONF or software conforming to a predetermined communication protocol such as Netconf/YANG can be adopted.
However, the switch control unit 53 of the present embodiment is software that conforms to OpenFlow, which has many device-independent APIs and is highly versatile. Therefore, the switch control unit 53 functions as an OpenFlow controller, and the line concentrator 3 functions as an OpenFlow switch.

The switch control unit 53 sets a communication frame transfer rule applied to the line concentrator 3 based on an operation input to the operation unit 44 by an operator of the communication carrier.
The switch control unit 53 transmits the set transfer rule to the line concentrator 3 by communication via an external API (southbound API) 55 . The line concentrator 3 determines the physical port for sending the received frame according to the transfer rule acquired from the switch control unit 53 .

[OLT aggregation type optical communication system]
FIG. 3 is a schematic diagram showing an example of a connection form (topology) of an optical communication system in which a plurality of small OLTs 1 are connected to one concentrator 3. As shown in FIG.
As shown in FIG. 3, the OpenFlow-compatible concentrator 3 includes a plurality of physical ports Pi (i=1, 2, . . . n) and a plurality of physical ports Q1 to Q4.

Physical ports Pi (i=1, 2, . . . n) are physical ports for OLT1. The physical port Q1 is a physical port for the switch control unit 53 (for OpenFlow). The physical port Q2 is a physical port for the OLT setting unit 52 (for VOLTHA).
A physical port Q3 is a physical port for the middleware section 48 . The physical port Q4 is a physical port for main signals. In FIG. 3, it is assumed that the middleware unit 48 operates for the DBA application 49A, but it may be other applications 49B and 49C.
Since the OLT 1 of this embodiment is a small communication device made up of SFP modules, a plurality of small OLTs 1 can be directly connected to physical ports Pi (i=1, 2 .
Therefore, it is possible to configure an OLT aggregation type optical communication system in which a plurality of small OLTs 1 are integrated in the housing of the concentrator 3 . If the OLT 1 is not a direct connection type or is large, each OLT 1 may be indirectly connected to the physical port Pi by a LAN cable or the like.

In the present embodiment, "direct connection" means connecting the communication device directly to the physical port Pi of the concentrator 3 without a cable.
"Indirect connection" means connecting the communication device to the physical port Pi of the concentrator 3 via a cable, or connecting the communication device to the concentrator 3 via a network or a relay device.

When the small OLT 1 is connected to multiple physical ports Pi of the concentrator 3, if the OLT 1 is identified by device-specific identification information such as a MAC address, the OLT setting unit 52 can specify the destination and source of the setting frame regardless of which physical port Pi the OLT 1 is connected to.
In this embodiment, predetermined tag information (for example, a VID value) of a communication frame is used to logically associate communications between communication devices connected to the line concentrator 3 in a one-to-one relationship. The association of VID values is executed by the switch control section (OpenFlow) 53 .

For example, by setting the VID value of the setting frame communicated between the OLT setting unit 52 and the plurality of OLTs 1 to be different for each OLT 1, the OLT setting unit 52 and the plurality of OLTs 1 can be logically associated on a one-to-one basis.
By setting the VID value in the same way as described above for the functional frames used for communication between the middleware section 48 and the plurality of OLTs 1, the middleware section 48 and the plurality of OLTs 1 can be logically associated on a one-to-one basis.

However, the tag information that logically identifies the type of communication frame in the concentrator 3 is not limited to the VID value described in the VLAN tag.
That is, the tag information for specifying the communication path in the concentrator 3 may be a value described in an existing information area other than the VLAN included in the communication frame, or a value described in a predetermined information area uniquely defined in the communication frame.

In the optical communication system of FIG. 3, the middleware unit 48, the OLT setting unit 52, and the switch control unit 53 may be software components installed in different communication devices (such as general-purpose servers) connected to the line concentrator 3.
Also, two of the above three types of software components may be installed in the first communication device (first general-purpose server), and the remaining one may be installed in another second communication device (second general-purpose server).

In the optical communication system of FIG. 3, the general-purpose server 4 including at least one of the switch control unit 53 and the OLT setting unit 52 may be connected to the concentrator 3 via a network or a relay device instead of being connected to the concentrator 3 with a cable.
The physical ports Q2-Q4 of the concentrator 3 may be merged into one or two physical ports. When the physical ports Q2 to Q4 are integrated in this manner, the VID value may be exclusively assigned according to the type of communication frame.

[Problems in mounting an accelerator on a small OLT]
FIG. 4 is a block diagram showing an example of an optical communication system when the application component 49 migrated to the general-purpose server 4 is a DBA application (hereinafter referred to as "comparative example 1"). In FIG. 4, the host device 5 is omitted for simplification of illustration.
As shown in FIG. 4 , the general-purpose server 4 includes a DBA application 49 A, a middleware section 48 for DBA (hereinafter referred to as “DBA common function section 48 A”), an OLT setting section 52 and a switch control section 53 . The DBA common function unit 48A and the DBA application 49A are connected by an internal API 50A.

The small OLT 1 includes a housing 10 and an FPGA 11 housed in the housing 10 . The FPGA 11 is a hardware component that communicates with the DBA common function unit 48A.
A frame processing unit 12A is configured in the FPGA 11 . The frame processing unit 12A of the FPGA 11 is an accelerator that executes generation, transmission and reception of DBA control frames. Therefore, the frame processing unit 12A is also called "DBA accelerator 12A".

The DBA accelerator 12A stores uplink transmission request amounts (report information) included in the reports received from the ONUs 2 . The DBA accelerator 12A generates a batch report containing the accumulated transmission request amount of each ONU 2, and transmits the generated batch report to the DBA common function unit 48A.
The DBA accelerator 12A extracts grant information for each LLID from the batch gate received from the DBA common function unit 48A. The DBA accelerator 12A generates a gate including grant information for each LLID and transmits the generated gate to the ONU2.

FIG. 5 is a block diagram showing an example of an optical communication system (hereinafter referred to as “comparative example 2”) in which the application components 49 migrated to the general-purpose server 4 are a DBA application 49A and a power saving application 49B. Also in FIG. 5, the host device 5 is omitted for simplification of illustration.
As shown in FIG. 5, the general-purpose server 4 includes, in addition to DBA-related software components, a power saving application 49B and a power saving middleware section 48 (hereinafter referred to as "power saving common function section 48B"). The power saving common function part 48B and the power saving application 49B are connected by an internal API 50B.

The small OLT 1 includes a housing 10 and an FPGA 11 housed in the housing 10 . The FPGA 11 is a hardware component that communicates with the common function units 48A and 48B.
The FPGA 11 includes a frame processing section 12B in addition to the frame processing section 12A. The frame processing unit 12B is an accelerator that generates, transmits, and receives power saving control frames. Therefore, the frame processing unit 12B is also called "power saving accelerator 12B".

The power saving accelerator 12B accumulates the user data transmission amount (bandwidth information) of each ONU 2 per unit time. The power saving accelerator 12B generates a collective bandwidth notification including the accumulated user data transmission amount of each ONU 2, and transmits the generated collective bandwidth notification to the power saving common function unit 48B.
The power saving accelerator 12B extracts sleep information (sleep start time and sleep period) for each LLID from the collective PS notification received from the power saving common function unit 48B. The frame processing unit 12B generates a power saving message including sleep information for each LLID and transmits the generated power saving message to the ONU2.

As shown in FIGS. 4 and 5, the method of mounting accelerators (frame processing units) 12A and 12B for transmitting and receiving information necessary for executing application components 49A and 49B to and from other communication devices on the FPGA 11 of the small OLT 1 has the following problems.

Problem 1: Problems Concerning Addition of Functions It is preferable that the small OLT 1 have a simple hardware configuration with fixed functions as much as possible. However, if the accelerators 12A and 12B are mounted on the small OLT 1, there is a possibility that the FPGA 11 of a size that can be mounted on the small OLT 1 will not be able to keep up with the addition of functions in the future.
For example, in addition to the accelerators 12A and 12B in FIG. 4, if it is necessary to add an accelerator corresponding to another application component 49 (for example, the OAM application 49C) to the FPGA 11, there is a possibility that the capacity of the FPGA 11 will become a bottleneck and the function cannot be added.

Problem 2: Problem Concerning Power Limitation The advantage of the compact OLT 1 made up of SFP modules is that it can operate only with power supply from the line concentrator 3 . However, if the number of accelerators 12A and 12B configured in the FPGA 11 increases, there is a possibility that power supply from the line concentrator 3 will run short.
In this case, it is conceivable to operate the small OLT 1 with an external power supply, but in this case, the external power supply must be increased according to the number of connections of the small OLT 1, which complicates the handling of cables including power lines.

[Problem solutions and implementation examples]
In this embodiment, in order to solve the problems 1 and 2, FPGA type communication modules 6A and 6B are adopted as target devices to be connected to the concentrator 3 separately from the small OLT 1, and accelerators for relaying communication between the small OLT 1 and the common function units 48A and 48B are configured in the FPGAs of the communication modules 6A and 6B.
6 to 8 are implementation examples of optical communication systems according to the above solutions. Also in FIGS. 6 to 8, the host device 5 is omitted for simplification of illustration. Hereinafter, mounting examples 1 to 3 of the optical communication system according to the above solution will be described with reference to FIGS. 6 to 8. FIG.

(Example 1 of implementation of optical communication system)
FIG. 6 is a block diagram showing an implementation example (hereinafter referred to as "implementation example 1") of an optical communication system having communication modules 6A and 7A for DBA.
Of the two types of communication modules 6A and 7A shown in FIG. 6, the communication module 6A is an FPGA-type communication module having an internal FPGA. The communication module 7A is a CPU-type communication module that executes the DBA application 49A.

The communication modules 6A and 7A consist of SFP modules like the small OLT 1, and can be directly connected to the physical ports Pi (i=1, 2 . . . n) of the line concentrator 3. FIG.
The same applies to the communication modules 6B, 6C and the communication module 7B shown in FIGS. Therefore, hereinafter, the "communication module" is also referred to as a "pluggable module".

The FPGA type communication modules 6A to 6C are collectively referred to as "communication module 6", and the CPU type communication modules 7A to 7B are collectively referred to as "communication module 7".
Furthermore, integrated circuits such as FPGAs that perform hardware acceleration, such as the DBA accelerator 61A and power saving accelerator 61B, are collectively referred to as "accelerator 61" or "hardware accelerator 61".

In implementation example 1, the DBA function, which is part of the PON function, is transferred to the pluggable module 7A instead of the general-purpose server 4. FIG.
Further, in implementation example 1, the OLT setting unit 52 and the switch control unit 53 remain in the general-purpose server 4 . However, the OLT setting unit 52 and the switch control unit 53 may be software components installed in separate communication devices connected to the line concentrator 3 .

The CPU-type pluggable module 7A includes a DBA application 49A and a DBA common function section 48A, which is a middleware section 48 for DBA. The DBA common function unit 48A and the DBA application 49A are connected by an internal API 50A.

The FPGA-type pluggable module 6A includes a housing 60 and a DBA accelerator 61A configured in the FPGA within the housing 60 .
The DBA accelerator 61A is a hardware component that communicates with the small OLT 1 and the DBA common function unit 48A of the pluggable module 7A. The DBA accelerator 61A is an accelerator that executes communication with the small OLT 1 and generation, transmission and reception of DBA control frames.

In the implementation example 1 of FIG. 6, the small OLT 1 outputs the report from the ONU 2 connected to itself to the line concentrator 3 as it is. The concentrator 3 transfers the report input from the small OLT 1 to the DBA accelerator 61A.
The DBA accelerator 61A accumulates the upstream transmission request amount (report information) included in the report of each ONU 2 received from the small OLT 1 . The DBA accelerator 61A generates a batch report summarizing the accumulated transmission request amount, and transfers the generated batch report to the DBA common function unit 48A of the pluggable module 7A.

The DBA common function unit 48A inputs the transmission request amount of each ONU 2 described in the batch report to the DBA application 49A via the internal API 50A.
The DBA application 49A executes a predetermined DBA algorithm using the input transmission request amount of each ONU 2 as a variable, and calculates grant information (transmission start time and transmission time length) to be assigned to each ONU 2 for each LLID. The DBA application 49A inputs the calculated grant information to the DBA common function unit 48A via the internal API 50A.

The DBA common function unit 48A generates a batch gate including the grant information of each ONU 2 input from the DBA application 49A, and transfers the generated batch gate to the DBA accelerator 61A.
The DBA accelerator 61A extracts grant information for each LLID from the batch gate received from the DBA common function unit 48A. The DBA accelerator 61A generates a control frame containing the LLID and grant information (hereinafter referred to as "grant control frame") and transmits the generated control frame to the physical port Pi of the small OLT1.

In this case, the DBA accelerator 61A adjusts the transmission timing of the grant control frame according to the transmission start time included in the grant information. The small OLT 1 converts the received grant control frame into a gate and transfers it to the PON line.

In implementation example 1 of FIG. 6, communications in the concentrator 3 by the small OLT 1, the pluggable modules 6A and 7A, and the OLT setting unit 52 are logically associated one-to-one by the transfer rule set by the switch control unit (OpenFlow) 53.
Since the FPGA type pluggable module 6A is commonly used by a plurality of small OLTs 1, it is necessary to set the correspondence between the small OLT 1 and the LLID in the pluggable module 6A. Such setting is performed by the OLT setting unit (VOLTHA) 52 .

Specifically, the OLT setting unit (VOLTHA) 52 collects the LLID values of the registered ONUs 2 from the small OLT 1 using the VOLTHA frame, and notifies the pluggable modules 6A and 7A of setting information representing the correspondence between the collected LLID values and the small OLT 1.

(Mounting example 2 of optical communication system)
FIG. 7 is a block diagram showing an implementation example (hereinafter referred to as “implementation example 2”) of an optical communication system in which power-saving communication modules 6B and 7B are added to the implementation example 1 of FIG.
Of the two types of communication modules 6B and 7B added in FIG. 7, the communication module 6B is an FPGA-type communication module having an internal FPGA. The communication module 7B is a CPU-type communication module that executes the power saving application 49B.

The configuration and operation of the pluggable modules 6A and 7A for DBA, the OLT setting unit 52 and the switch control unit 53 are the same as in the implementation example 1 of FIG.
Therefore, the configuration and operation of the power saving pluggable modules 6B and 7B will be mainly described below.

In implementation example 2, the DBA function and power saving control, which are part of the PON function, are transferred to the respective pluggable modules 7A and 7B instead of the general-purpose server 4. FIG.
Also, in implementation example 2, the OLT setting unit 52 and the switch control unit 53 remain in the general-purpose server 4 . However, the OLT setting unit 52 and the switch control unit 53 may be software components installed in separate communication devices connected to the line concentrator 3 .

The CPU-type pluggable module 7B includes a power saving application 49B and a power saving common function section 48B which is a middleware section 48 for power saving. The power saving common function part 48B and the power saving application 49B are connected by an internal API 50B.

The FPGA type pluggable module 6B includes a housing 60 and a power saving accelerator 61B configured in the FPGA within the housing 60 .
The power saving accelerator 61B is a hardware component that communicates with the small OLT 1 and the power saving common function part 48B of the pluggable module 7B. The power saving accelerator 61B is an accelerator that executes communication with the small OLT 1 and generation, transmission and reception of power saving control frames.

In the implementation example 2 of FIG. 7, the small OLT 1 outputs the band notification including the user data transmission amount per unit time (bandwidth information) of the ONUs 2 connected to itself to the concentrator 3 as it is. The line concentrator 3 transfers the band notification input from the small OLT 1 to the power saving accelerator 61B.
The power saving accelerator 61B accumulates the user data transmission amount of each ONU 2 received from the small OLT 1 . The power saving accelerator 61B generates a collective bandwidth notification summarizing the amount of accumulated user data, and transfers the generated collective bandwidth notification to the power saving common function unit 48B of the pluggable module 7B.

The power saving common function unit 48B inputs the user data transmission amount of each ONU 2 described in the batch band notification to the power saving application 49B via the internal API 50B.
The power saving application 49B executes a predetermined power saving algorithm using the input user data transmission amount of each ONU 2 as a variable, and calculates sleep information (sleep start time and sleep period) of each ONU 2 for each LLID. The power saving application 49B inputs the calculated sleep information to the power saving common function unit 48B via the internal API 50B.

The power saving common function unit 48B generates a collective PS notification including the sleep information of each ONU 2 input from the power saving application 49B, and transfers the generated collective PS notification to the power saving accelerator 61B.
The power saving accelerator 61B extracts sleep information for each LLID from the collective PS notification received from the power saving common function unit 48B. The power saving accelerator 61B generates a control frame including the LLID and sleep information (hereinafter referred to as "sleep control frame"), and transmits the generated sleep control frame to the physical port Pi of the small OLT 1.

In this case, the power saving accelerator 61B adjusts the transmission timing of the sleep control frame according to the transmission start time included in the sleep information. The small OLT 1 converts the received sleep control frame into a PON message and transfers it to the PON line.

In implementation example 2 of FIG. 7, communications in the concentrator 3 by the small OLT 1, the pluggable modules 6A and 7A, the pluggable modules 6B and 7B, and the OLT setting unit 52 are logically associated one-to-one by the transfer rule set by the switch control unit (OpenFlow) 53.
Since the FPGA-type pluggable modules 6A and 6B are commonly used by a plurality of small OLTs 1, it is necessary to set the correspondence between the small OLT 1 and the LLID in the pluggable modules 6A and 6B. Such setting is performed by the OLT setting unit (VOLTHA) 52 .

Specifically, the OLT setting unit (VOLTHA) 52 collects the LLID values of the registered ONUs 2 from the small OLT 1 using the VOLTHA frame, and notifies the pluggable modules 6A and 7A and the pluggable modules 6B and 7B of setting information representing the correspondence between the collected LLID values and the small OLT 1.

(Mounting example 3 of optical communication system)
FIG. 8 is a block diagram showing an implementation example (hereinafter referred to as "implementation example 3") of an optical communication system in which another communication module 6C is added to the implementation example 2 of FIG.
The communication module 6C added in FIG. 8 is an FPGA-type communication module having an FPGA therein.

The configurations and operations of the DBA pluggable modules 6A and 7A and the power saving pluggable modules 6B and 7B, as well as the OLT setting unit 52 and the switch control unit 53, are the same as in the implementation example 2 of FIG.
Therefore, the configuration and operation of the newly added pluggable module 6C will be mainly described below.

The FPGA-type pluggable module 6C includes a housing 60 and a frame distribution section 61C configured in the FPGA within the housing 60. FIG.
The frame distribution unit 61C is a hardware component that communicates with the small OLT 1, the DBA accelerator 61A and the power saving accelerator 61B. Specifically, the frame distribution unit 61C is an accelerator that executes processing for distributing the transmission destinations of the grant control frame and the sleep control frame for each small OLT 1 .

In the implementation example 3 of FIG. 8, the small OLT 1 outputs the report and band notification of the ONU 2 connected to itself to the concentrator 3 as they are. The line concentrator 3 transfers the U-report and band notification input from the small OLT 1 to the pluggable module 6C.
The frame distribution unit 61C has a VLAN table and a MAC address list. The frame distribution unit 61C executes distribution processing for determining the destination of the received frame using the address information defined therein.

For example, when the received frame is a report from the small OLT 1, the frame distribution unit 61C transfers the received report to the DBA accelerator 61A.
Similarly, when the received frame is a bandwidth notification from the small OLT 1, the frame distribution unit 61C transfers the received bandwidth notification to the power saving accelerator 61B.

When the received frame is a grant information frame from the DBA accelerator 61A, the frame distribution unit 61C determines the destination small OLT 1 based on the VID value, and transfers the grant information frame to the determined destination small OLT 1.
Similarly, when the received frame is a sleep information frame from the power saving accelerator 61B, the frame distribution unit 61C determines the destination small OLT 1 based on the VID value, and transfers the sleep information frame to the determined destination small OLT 1.

[Effects of Implementation Examples 1 to 3 of Optical Communication System]
According to the implementation examples 1 to 3 of the optical communication system of the present embodiment, the communication module 6 having the hardware accelerator 61 that reduces the load on the CPU is connected to the concentrator 3 to which the small OLT 1 is connected.
Therefore, the hardware configuration of the small OLT 1 can be further simplified and fixed, and the generalization of the small OLT 1 can be promoted.

According to implementation examples 1 to 3 of the present embodiment, when adding a PON function to be softwareized, it can be handled by adding the communication modules 6 and 7 (see FIGS. 6 to 8), so it is possible to flexibly cope with the addition of functions.
Therefore, it is possible to obtain an optical communication system that can flexibly cope with addition of functions in the future without changing the hardware configuration of the small OLT 1 .

In addition, even if there is a need to add functions, there is no need to change the hardware configuration of the small OLT 1, so the small OLT 1 can be operated by power supply from the line concentrator 3 regardless of whether or not functions are added.
Therefore, there is no need to operate the small OLT 1 with an external power supply, and cable handling in the OLT aggregate type optical communication system can be simplified.

According to implementation examples 1 to 3 of the present embodiment, it is not necessary to mount an optical transceiver and accompanying physical layer parts on the FPGA type pluggable module 6 . Therefore, a large-scale FPGA can be mounted compared to the case where the FPGA 11 is mounted on the small OLT 1 .
Moreover, even if an external power supply is required, it is sufficient to plug a small number of pluggable modules 6 and 7 into the concentrator 3, so the flexibility of the system is not compromised. Furthermore, there is the advantage that addition/deletion of PON functions can be easily executed simply by increasing or decreasing the number of pluggable modules 6 and 7, and the system configuration can be flexibly changed as required.

According to implementation examples 1 to 3 of this embodiment, the small OLT 1 and the communication module 6 are pluggable modules that are directly connected to the concentrator 3, so control frames such as report and grant control frames are transmitted and received within the concentrator 3.
Therefore, the transmission delay of control frames is less than in the case where at least one of the small OLT 1 and the communication module 6 is connected to the concentrator 3 with a cable. Therefore, the execution speed of the application component 48 by the CPU (for example, DBA cycle) can be increased.

According to implementation examples 1 to 3 of the present embodiment, since the communication modules 6 and 7 are pluggable modules that are directly connected to the concentrator 3, control frames such as DBA control frames and power saving control frames are transmitted and received within the concentrator 3.
Therefore, compared with the case where at least one of the communication modules 6 and 7 is connected to the concentrator 3 with a cable or the case where the application component 48 is installed in the general-purpose server 4, the transmission delay of the control frame is small. Therefore, the execution speed of the application component 48 by the CPU (for example, DBA cycle) can be increased.

[Transfer Control in Concentrator]
FIG. 9 is a block diagram showing an example of transfer control in the line concentrator 3. As shown in FIG.
As shown in FIG. 9, the small OLT 1 has an LLID-VLAN conversion function that converts the LLID value of the user frame into the VID value for the user on a one-to-one basis.
A transfer rule is set in the concentrator 3 to determine which of the small OLT 1 and the host device 5 the user frame should be transferred to, based on the VID value included in the user frame. Therefore, user frames are transferred between the small OLT 1 and the host device 5 within the line concentrator 3 .

As shown in FIG. 9, the small OLT 1 assigns a predetermined VID value to the report received from the ONU 2 and inputs it to the line concentrator 3 . The small OLT 1 deletes a predetermined VID value from the grant control frame received from the pluggable module 6A, converts it into a gate, and sends it out to the PON line.
For control frames transmitted from the small OLT 1 and the pluggable modules 6A and 7A for DBA, a predetermined VID value is defined for each type of the control frame.

A transfer rule is set in the concentrator 3 to determine which of the small OLT 1 and the pluggable modules 6A and 7A the transfer destination of the control frame is to be, based on the VID value included in the control frame. Therefore, control frames are properly transferred between the small OLT 1 and the pluggable modules 6A and 7A within the concentrator 3. FIG.
Although not shown in FIG. 9, transfer control similar to the above is executed for control frames transmitted and received between the small OLT 1 and the power saving pluggable modules 6B and 7B.

[Internal configuration of small OLT]
FIG. 10 is a block diagram showing an example of the internal configuration of the small OLT 1. As shown in FIG.
As shown in FIG. 10, the small OLT 1 comprises a lower transmitting/receiving section 21, a frame processing section 22, and an upper transmitting/receiving section 23 in order from left to right in the figure.

The lower transmitting/receiving unit 21 is a signal transmitting/receiving device including an optical transceiver.
The lower transmitting/receiving unit 21 converts an upstream optical signal from the ONU 2 into an electrical signal. The lower transmitting/receiving section 21 outputs the upstream frame reproduced from the converted electrical signal to the upstream reception processing section 24 of the frame processing section 22 .
The lower transmitting/receiving section 21 converts the downstream frame input from the downstream transmission processing section 27 of the frame processing section 22 into a downstream optical signal of a predetermined wavelength band. The lower transmitting/receiving unit 21 transmits the converted downstream optical signal to the PON line.

The upper transmitting/receiving unit 23 is a transmitting/receiving device for Ethernet signals.
The upper transmitting/receiving unit 23 demodulates the Ethernet signal input from the line concentrator 3 and reproduces the downstream frame. The upper transmitting/receiving section 23 outputs the reproduced downstream frame to the downstream reception processing section 26 of the frame processing section 22 .
The upper transmitting/receiving section 23 modulates the upstream frame input from the upstream transmission processing section 25 of the frame processing section 22 into an Ethernet signal of a predetermined frequency. The upper transmitting/receiving unit 23 sends the modulated Ethernet signal to the line concentrator 3 .

The frame processing unit 22 is composed of an integrated circuit such as an FPGA, which has a MAC function. The frame processing unit 22 may include part of the functions of the PHY layer, or part or all of it may be composed of an integrated circuit such as an ASIC (Application Specific Integrated Circuit).

The frame processing section 22 includes an uplink reception processing section 24 , an uplink transmission processing section 25 , a downlink reception processing section 26 and a downlink transmission processing section 27 .
The frame processing unit 22 also includes an upstream buffer 29 , a downstream buffer 30 , a setting processing unit (VOLTHA processing unit) 31 , and an ID conversion table 32 .

When the upstream frames input from the lower transmitting/receiving unit 21 are user frames and reports, the upstream reception processing unit 24 outputs these frames to the upstream buffer 29 .
At this time, the upstream reception processing unit 24 refers to the ID conversion table 32 for the user frame, performs ID conversion from the LLID value to the VID value, and attaches a VLAN tag including the converted VID value to the user frame. The upstream reception processing unit 24 assigns a predetermined VID value to the report.

The upstream reception processing unit 24 calculates the user data transmission amount (bandwidth information) of each ONU 2 from the data amount included in the user frames received per unit time.
The upstream reception processing unit 24 generates a bandwidth notification including the calculated bandwidth information for each ONU 2 and outputs the generated bandwidth notification for each ONU 2 to the upstream buffer 29 . The upstream reception processing unit 24 also assigns a predetermined VID value to the band notification.

The upstream transmission processing unit 25 extracts the user frame, the report and the band notification from the upstream buffer 29 and outputs them to the upper transmitting/receiving unit 23 . The upper transmitting/receiving unit 23 converts the input user frame, report, and band notification into an Ethernet signal and transmits the Ethernet signal to the line concentrator 3 .
The types of upstream frames processed by the upstream transmission processing unit 25 include VOLTHA frames, user frames, and reports. The upstream transmission processing unit 25 preferably sets the transmission priority of these types to VOLTHA frame>report>bandwidth notification>user frame.

When the downstream frame input from the upper transmitting/receiving section 23 is a user frame, a grant control frame, or a sleep control frame, the downstream reception processing section 26 outputs these frames to the downstream buffer 30 .
At this time, the downstream reception processing unit 26 performs ID conversion from the VID value to the LLID value for the user frame by referring to the ID conversion table 32, and writes the converted LLID value in the header of the user frame. The downlink reception processing unit 26 also converts the grant control frame into a gate and the sleep control frame into a power saving message.

The downstream transmission processing unit 27 extracts the user frame, the gate and the power saving message from the downstream buffer 30 and outputs them to the lower transmitting/receiving unit 21 . The lower transmitting/receiving unit 21 converts the input user frame, gate, and power saving message into a downstream optical signal and transmits the downstream optical signal to the ONU 2 .
The types of downstream frames processed by the downstream transmission processing unit 27 include two types of user frames, gates, and power saving messages. The downstream transmission processing unit 27 preferably sets the transmission priority of these types as follows: gate>power saving message>user frame.

When the downstream frame input from the upper transmitting/receiving section 23 is a VOLTHA frame with a predetermined VID value, the downstream reception processing section 26 outputs the frame to the VOLTHA processing section 31 .
The VOLTHA processing unit 31 performs a predetermined setting process according to the command written in the VOLTHA frame. For example, when the command of the VOLTHA frame is a request for the LLID value, the VOLTHA processing unit 31 reads the LLID value of the registered ONU 2 from the ID conversion table 32 and includes the read LLID value in the response VOLTHA frame.

When a new ONU 2 is registered, the VOLTHA processing unit 31 transmits a VOLTHA frame including the LLID value of the new ONU 2 to the OLT setting unit 52 and requests the OLT setting unit 52 to allocate a VID value for user frames corresponding to the LLID value.
Alternatively, the OLT setting unit 52 may periodically poll the VOLTHA processing unit 31 with a VOLTHA frame requesting the ONU 2 registration status, and the VOLTHA processing unit 31 may respond with the new LLID value of the ONU 2 in response to the request for the registration status.

If the VOLTHA frame contains new ID correspondence information, the VOLTHA processing unit 31 updates the contents of the ID conversion table 32 according to the notified ID correspondence information.
The VOLTHA frame is a communication frame terminated by the OLT 1 and returned to the OLT setting unit 52 . Accordingly, when the VOLTHA frame is input from the downstream reception processing unit 26 , the VOLTHA processing unit 31 generates a communication frame (response VOLTHA frame) with a predetermined VID value and outputs it to the upstream transmission processing unit 25 .

[Internal configuration of FPGA type communication module]
FIG. 11 is a block diagram showing a circuit configuration example of the FPGA in the FPGA type communication module 6A. A communication module 6A in FIG. 11 is for a DBA.
As shown in FIG. 11, the communication module 6A includes a housing 60 and a DBA accelerator 61A configured in an FPGA within the housing 60. As shown in FIG.

The DBA accelerator 61A includes a DBA control unit 63, a gate processing unit 64, a report processing unit 65, a transmission processing unit 66, a reception processing unit 67, and a transmission/reception unit 68 in order from left to right in the drawing.

The transmitter/receiver 68 is a circuit portion that transmits and receives Ethernet signals.
The transmission/reception unit 68 demodulates the Ethernet signal input from the line concentrator 3 and reproduces the control frame. The transmission/reception unit 68 outputs the reproduced control frame to the reception processing unit 67 .
The transmission/reception unit 68 modulates the control frame input from the transmission processing unit 66 into an Ethernet signal. The transmitter/receiver 68 sends the modulated Ethernet signal to the line concentrator 3 .

The reception processing unit 67 classifies the control frames received from the concentrator 3 by type. The types classified by the reception processing unit 67 include the following types 1 to 3.
Type 1: A report from the small OLT 1 storing the transmission request amount of one ONU 2 Type 2: A batch gate from the pluggable module 7A collectively storing grant information for at least one ONU 2 Type 3: A setting frame for the DBA accelerator 61A from the OLT setting unit 52

The reception processing unit 67 outputs the type 1 report to the report processing unit 65 . The reception processing unit 67 outputs the batch gate of type 2 to the gate processing unit 64 . The reception processing unit 67 outputs the setting frame of type 3 to the DBA control unit 63 .
The report processing unit 65 has a buffer (not shown) for accumulating the transmission request amount for each LLID included in the type 1 report. The report processing unit 65 extracts the transmission request amount of each ONU 2 from a plurality of reports input within the DBA cycle and stores it in a buffer.

The report processing unit 65 generates a batch report for each DBA cycle, and includes the LLID and the corresponding transmission request amount in the generated batch report. The report processing unit 65 stores data in a buffer and generates a batch report for each OLT 1 .
The report processing unit 65 outputs to the transmission processing unit 66 a batch report including the requested transmission amount for each LLID. The transmission processing unit 66 outputs the input batch report to the transmission/reception unit 68 . The transmission/reception unit 68 outputs the input batch report to the line concentrator 3 . The concentrator 3 transfers the input batch report to the DBA pluggable module 7A.

The gate processing unit 64 extracts grant information (transmission start time and transmission time length) for each LLID assigned to each ONU 2 from the type 2 batch gate.
The gate processing unit 64 generates a grant control frame including grant information of one ONU 2 for each LLID and outputs the generated grant control frame to the transmission processing unit 66 . The transmission processing unit 66 outputs the input grant control frame to the transmission/reception unit 68 . The transmitting/receiving unit 68 outputs the input grant control frame to the concentrator 3 . The concentrator 3 transfers the input grant control frame to the corresponding small OLT 1 .

Based on the type 3 setting frame, the DBA control unit 63 executes a predetermined setting process for each of the processing units 64 to 67 of its own device.
For example, the setting frame from the OLT setting unit 52 includes setting information representing the correspondence between the LLID value and the small OLT 1 . Based on the acquired setting information, the DBA control unit 63 specifies the VID value of the small OLT 1 corresponding to the LLID value of the received frame, and instructs the transmission processing unit 66 and the reception processing unit 67 to transmit and receive control frames using the specified VID value.

According to the FPGA type communication module (communication device) 6A of the present embodiment, the report processing unit 65 converts the received report into a batch report and inputs it to the transmission/reception unit 68, and the gate processing unit 64 converts the received batch gate into a grant control frame and inputs it to the transmission/reception unit 68. Therefore, the small OLT 1 only needs to transmit and receive the report and the grant control frame. Therefore, it becomes unnecessary to mount an accelerator for conversion processing of batch reports and batch gates in the small OLT 1 .
Therefore, the hardware configuration of the small OLT 1 can be further simplified and fixed, and the generalization of the small OLT 1 can be promoted.

FIG. 12 is a block diagram showing a circuit configuration example of the FPGA in the FPGA type communication module 6B. The communication module 6B of FIG. 12 is for power saving.
As shown in FIG. 12, the communication module 6B includes a housing 60 and a power saving accelerator 61B configured in an FPGA within the housing 60. As shown in FIG.

The power saving accelerator 61B includes a power saving control unit 83, a PS processing unit 84, a band notification processing unit 85, a transmission processing unit 86, a reception processing unit 87, and a transmission/reception unit 88 in order from left to right in the figure.

The transmitter/receiver 88 is a circuit portion that transmits and receives Ethernet signals.
The transmission/reception unit 88 demodulates the Ethernet signal input from the line concentrator 3 and reproduces the control frame. The transmission/reception unit 88 outputs the reproduced control frame to the reception processing unit 87 .
The transmission/reception unit 88 modulates the control frame input from the transmission processing unit 86 into an Ethernet signal. The transmitter/receiver 88 sends the modulated Ethernet signal to the line concentrator 3 .

The reception processing unit 87 classifies the control frames received from the concentrator 3 by type. The types classified by the reception processing unit 87 include the following types 4 to 6.
Type 4: Bandwidth notification from small OLT 1 storing bandwidth information of one ONU 2 Type 5: Batch PS notification from pluggable module 7B storing sleep information of at least one ONU 2 Type 6: Power saving accelerator 61B setting frame from OLT setting unit 52

The reception processing unit 87 outputs the type 4 band notification to the band notification processing unit 85 . The reception processing unit 87 outputs the batch PS notification of type 5 to the PS processing unit 84 . The reception processing unit 87 outputs the setting frame of type 6 to the power saving control unit 83 .
The bandwidth notification processing unit 85 has a buffer (not shown) for accumulating the user data transmission amount (bandwidth information) for each LLID included in the type 1 bandwidth notification. The bandwidth notification processing unit 85 extracts the user data transmission amount of each ONU 2 from a plurality of bandwidth notifications input within a predetermined period and stores it in a buffer.

The bandwidth notification processing unit 85 generates a batch bandwidth notification for each predetermined period, and includes the LLID and the corresponding user data transmission amount in the generated batch bandwidth notification. The bandwidth notification processing unit 85 executes accumulation in the buffer and generation of collective bandwidth notification for each OLT 1 .
The bandwidth notification processing unit 85 outputs to the transmission processing unit 86 a collective bandwidth notification including the requested amount of user data for each LLID. The transmission processing unit 86 outputs the input collective band notification to the transmission/reception unit 88 . The transmitting/receiving unit 88 outputs the input batch band notification to the line concentrator 3 . The line concentrator 3 transfers the input collective band notification to the power saving pluggable module 7B.

The PS processing unit 84 extracts sleep information (sleep start time and sleep period) for each LLID assigned to the ONU 2 from the type 5 batch PS notification.
The PS processing unit 84 generates a sleep control frame including sleep information of one ONU 2 for each LLID, and outputs the generated sleep control frame to the transmission processing unit 86 . The transmission processing unit 86 outputs the input sleep control frame to the transmission/reception unit 88 . The transmission/reception unit 88 outputs the input sleep control frame to the line concentrator 3 . The concentrator 3 transfers the input sleep control frame to the corresponding small OLT 1 .

Based on the type 6 setting frame, the power saving control unit 83 executes a predetermined setting process for each of the processing units 84 to 87 of its own device.
For example, the setting frame from the OLT setting unit 52 includes setting information representing the correspondence between the LLID value and the small OLT 1 . Based on the acquired setting information, the power saving control unit 83 specifies the VID value of the small OLT 1 corresponding to the LLID value of the received frame, and instructs the transmission processing unit 86 and the reception processing unit 87 to transmit and receive control frames using the specified VID value.

According to the FPGA-type communication module (communication device) 6B of the present embodiment, the bandwidth notification processing unit 85 converts the received bandwidth notification into a batch bandwidth notification and inputs it to the transmission/reception unit 88, and the PS processing unit 84 converts the received batch PS notification into a sleep control frame and inputs it to the transmission/reception unit 88. Therefore, it is sufficient for the small OLT 1 to transmit and receive the bandwidth notification and the sleep control frame. Therefore, it becomes unnecessary to mount an accelerator for conversion processing of batch band notification and batch PS notification in the small OLT 1 .
Therefore, the hardware configuration of the small OLT 1 can be further simplified and fixed, and the generalization of the small OLT 1 can be promoted.

[Internal configuration of CPU type communication module]
FIG. 13 is a block diagram showing an example of the internal configuration of the CPU-type communication module 7. As shown in FIG.
As shown in FIG. 13 , the communication module 7 of this embodiment includes a housing 70 , and a control section 71 , a storage section 72 and a communication section 73 accommodated in the housing 70 .

The control unit 71 , storage unit 72 and communication unit 73 are attached to the back plane inside the housing 70 . The control unit 71 controls the operation of each hardware unit 72-73.
The control unit 71 is composed of an arithmetic processing unit including a CPU and a main memory composed of a RAM. The CPU of the control unit 71 reads a computer program (software) 76 installed in the storage unit 72 into the main memory, and performs various information processing according to the program 76 .

The storage unit 72 consists of a recording medium including at least one non-volatile memory such as ROM and SSD.
The communication unit 73 includes a communication interface that performs Ethernet (registered trademark) communication with an external device. Since the communication module 7 is a pluggable module, the communication section 73 has a connector for direct connection to the physical port Pi of the line concentrator 3 .

As shown in FIG. 13, a computer program 76 read from the storage unit 72 and executed by the CPU of the control unit 71 includes a middleware unit 48 that operates on the OS and one or more application components 49 . The application component 49 is created based on the internal API 50 , and the middleware section 48 is created based on the internal API 50 and the external API 51 .

The computer program 76 can be distributed as a software product by storing it in a removable recording medium such as a USB memory in addition to the recording medium that constitutes the storage unit 72 of the communication module 7 .
The computer program 76 can also be distributed as a software product through a public communication network such as the Internet.

As indicated by the solid line in FIG. 13, the application component 49 consists of a DBA application 49A. In this case, the communication module 7 is a DBA pluggable module 7A (see FIGS. 6 and 7).
As indicated by dashed lines in FIG. 13, the application component 49 may be a power saving application 49B or an OAM application 49C. When the application component 49 is a power saving application 49B, the communication module 7 is a power saving and CPU type pluggable module 7B (see FIG. 7).

The application components 49 included in the communication module 7 may be at least two of the DBA application 49A, power saving application 49B, and OAM application 49C, or other types of application components 49 may be included.
The internal API 50 is a device-independent input/output interface. The application components 49A-49C are connected to the middleware section 48 via internal APIs 50A-50C defined respectively for the application components 49A-49C.

The external API 51 is a device-dependent input/output interface. The middleware unit 48 is connected to hardware components of an external communication device (for example, accelerators 6A and 6B having a hardware configuration) via external APIs 51A to 51C defined respectively for application components 49A to 49C.
Therefore, the middleware section 48 inputs and outputs predetermined information to and from the hardware components of the external communication device by means of the external APIs 51A to 51C.

The information format of the external API 51 is standardized for each of the application components 49A-49C. The external API 51 includes control frames such as the "function frame" described above.
The functional frames include the above-mentioned "batch report", "batch gate", "batch bandwidth notification", and "batch PS notification".

[Procedure of DBA processing]
FIG. 14 is a sequence diagram showing the procedure of DBA processing in an optical communication system.
Specifically, FIG. 14 is a sequence diagram showing a procedure of DBA processing when two small OLTs 1X and 1Y and communication modules 6A and 7A for DBA are connected to the line concentrator 3. FIG.

In FIG. 14, the solid line arrows are communication frames related to the small OLT 1X, and the virtual line arrows are communication frames related to the small OLT 1Y. The number of connections of the small OLT 1 is not limited to two, and may be one or three or more.
As shown in FIG. 14, when the small OLTs 1X and 1Y receive reports from the ONUs 2 connected to the PON line connected to them, they transfer the received reports to the FPGA type communication module 6A.

Next, the communication module 6A extracts the requested transmission amount for each LLID from the received report, and generates a batch report including the extracted requested transmission amount for each ONU 2 . The communication module 6A transmits the generated batch report to the CPU type communication module 7A.
The FPGA-type communication module 6A executes the process of extracting the requested amount of transmission and the process of generating and transmitting the batch report in units of the small OLTs 1X and 1Y.

Next, the CPU-type communication module 7A applies a predetermined DBA algorithm to the transmission request amount of each LLID included in the batch report to calculate bandwidth allocation, and obtains grant information (transmission start time and transmission time length) for each LLID. The CPU-type communication module 7A also generates a batch gate including grant information for each LLID, and transmits the generated batch gate to the FPGA-type communication module 6A.
The CPU-type communication module 7A executes the above-described band allocation calculation, batch gate generation and transmission processing in units of the small OLTs 1X and 1Y.

Next, the FPGA type communication module 6A takes out the grant information of each LLID from the batch gate. The FPGA type communication module 6A generates a grant control frame including the extracted grant information for each LLID, and transmits the generated grant control frame for each LLID to the small OLT 1. FIG.
The FPGA-type communication module 6A executes the process of extracting the grant information and the process of generating and transmitting the grant control frame in units of the small OLTs 1X and 1Y.

Next, the small OLTs 1X and 1Y extract grant information from the received grant information frame of each LLID.
The small OLTs 1X and 1Y generate a gate including the extracted grant information for each LLID, and broadcast the generated gate for each LLID to the ONUs 2 under their control.

[Modified example of optical communication system]
FIG. 15 is a block diagram showing an implementation example of an optical communication system having a communication module 6D for image processing (hereinafter referred to as "modification").
A communication module 6D in FIG. 15 is an FPGA-type communication module having an FPGA therein. The communication module 6D is composed of an SFP module like the small OLT 1, and can be directly connected to the physical ports Pi (i=1, 2 . . . n) of the line concentrator 3. FIG.

In the implementation examples 1 to 3 (FIGS. 6 to 8) described above, the communication module 6 is a communication device that performs hardware acceleration of software components responsible for part of the PON functionality.
On the other hand, the communication module 6D of the modified example of FIG. In the modified example of FIG. 15, a security application 48D for notifying the user of the monitoring result is installed in the management device 8 as an application component for realizing a predetermined service.

As illustrated, the management device 8 is connected to the host device 5 via the host network, and the ONU 2 is connected to the user's surveillance camera 9 . Image data (for example, stream data) generated by the monitoring camera 9 is transmitted to the small OLT 1 as a main signal via the PON line.
The small OLT 1 converts the LLID value of the image data into a VID value, adds a VLAN tag to it, and sends the image data to the line concentrator 3 . The concentrator 3 transfers the image data to the FPGA type communication module 6D according to the VLAN tag.

The FPGA-type communication module 6D includes a housing 60 and an image processing accelerator 61D configured in the FPGA within the housing 60. FIG.
The image processing accelerator 61D executes predetermined image processing on the image data received from the line concentrator 3 . This image processing is, for example, based on the feature points detected from the image data, the state information of an object such as a specific person or vehicle (for example, an intrusion into the house by a person other than the family, or the presence in front of the entrance for a long time, etc.).

The image processing accelerator 61D generates a report frame containing state information of the recognized object. The image processing accelerator 61D adds a VLAN tag with a VID value different from that of the image data to the generated message frame, and outputs the message frame to the line concentrator 3 .
The concentrator 3 transfers the input notification frame to the host device 5 . The host device 5 transfers the notification frame received from the line concentrator 3 to the management device 8 having the security application 48D. The security application 49D of the management device 8 determines the degree of danger of the status information included in the received report frame, and if the degree of danger is equal to or greater than a predetermined value, notifies the mobile terminal of the user.

Since image processing for recognizing object state information from image data requires a relatively large amount of data processing, it is difficult to implement with the FPGA resources of the small OLT 1 .
In this regard, according to the modification of FIG. 15, the dedicated communication module 6D executes image processing, so there is no need to configure an image processing accelerator in the small OLT 1. FIG. Therefore, edge computing that reduces the processing load of the management device 8 can be easily realized without changing the hardware configuration of the small OLT 1 .

According to the modification of FIG. 15, there is no need to transmit the image data to the management device 8, so there is an advantage that the upstream communication band can be used effectively.
In the modified example of FIG. 15, when an accelerator for generating information necessary for executing an application component that provides a service other than a crime prevention service is required, an FPGA-type pluggable module equipped with the accelerator can be added to the line concentrator 3. Therefore, future addition of functions can be flexibly accommodated without changing the hardware configuration of the small OLT 1 .

[Other Modifications]
It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope of equivalence to the scope of claims.

For example, in the implementation examples 1 to 3 described above, the CPU-type communication modules 7A and 7B may be integrated with the general-purpose server 4. FIG. That is, software components such as the DBA application 49A and the power saving application 49B may be installed in the general-purpose server 4. FIG.
In this case, the accelerators 61A and 61B of the FPGA type communication modules 6A and 6B communicate with the common function units 48A and 48B mounted on the general-purpose server 4 via the line concentrator 3. FIG.

In the implementation examples 1 to 3 described above, the FPGA type communication modules 6A and 6B having Ethernet physical ports may be employed, and the corresponding CPU type communication modules 7A and 7B may be connected to the physical ports of the communication modules 6A and 6B.
In this case, the CPU type communication modules 7A and 7B are indirectly connected to the line concentrator 3 via the FPGA type communication modules 6A and 6B. Further, the accelerators 61A and 61B of the FPGA-type communication modules 6A and 6B communicate with the common function units 48A and 48B of the CPU-type communication modules 7A and 7B without passing through the line concentrator 3 .

In the mounting examples 1 to 3 described above, the components such as the control unit 71 of the CPU type communication modules 7A and 7B may be mounted on the circuit board housed in the housing 60 of the FPGA type communication modules 6A and 6B.
In this case, the accelerators 61A and 61B, which are components of the FPGA-type communication modules 6A and 6B, communicate with the common function units 48A and 48B of the control unit 71, which are components of the CPU-type communication modules 7A and 7B, via bus lines in the housing. Therefore, it can be said that the above integrated communication module also has a form in which the CPU type communication modules 7A and 7B are indirectly connected to the line concentrator 3 via the FPGA type communication modules 6A and 6B.

1 station side terminating equipment (OLT or small OLT)
1X Small OLT
1Y Small OLT
2 subscriber-side terminal unit (ONU)
3 Concentrator (L2SW)
4 general-purpose server (communication device)
5 Host device (communication device)
6 communication module 6A communication module (pluggable module, first communication device)
6B communication module (pluggable module, first communication device)
6C communication module (pluggable module)
6D communication module (pluggable module, first communication device) 7 communication module 7A communication module (pluggable module, second communication device)
7B communication module (pluggable module, second communication device)
8 Management device (second communication device)
9 surveillance camera 10 housing 11 FPGA
12A Frame processing unit (accelerator)
12B frame processor (accelerator)
21 lower-side transmitting/receiving unit 22 frame processing unit 23 upper-side transmitting/receiving unit 24 upstream reception processing unit 25 upstream transmission processing unit 26 downstream reception processing unit 27 downstream transmission processing unit 29 upstream buffer 30 downstream buffer 31 setting processing unit (VOLTHA processing unit)
32 ID conversion table 40 housing 41 control unit 42 storage unit 43 communication unit 44 operation unit 45 display unit 46 computer program (software)
47OS
48 middleware unit 48A DBA common function unit 48B power saving common function unit 49 application component (application component)
49A DBA application 49B Power saving application 49C OAM application 49D Security application 50 Internal API
50A-50C Internal API
51 external APIs
51A-51C External API
52 OLT setting unit 53 switch control unit 54 external API
55 external APIs
60 housing 61A DBA accelerator 61B power saving accelerator 61C frame sorting unit 61D image processing accelerator 63 DBA control unit 64 gate processing unit 65 report processing unit 66 transmission processing unit 67 reception processing unit 68 transmission/reception unit 70 housing 71 control unit 72 storage unit 73 communication unit 76 computer program (software)
83 power saving control unit 84 PS processing unit 85 band notification processing unit 86 transmission processing unit 87 reception processing unit 88 transmission/reception unit

Claims (10)

A PON system comprising one or more station-side terminating devices that terminate corresponding PON lines, and a concentrator to which the station-side terminating devices are directly or indirectly connected,
A PON system in which target devices directly or indirectly connected to the concentrator include the following first and second communication devices.
First communication device: A communication device having a hardware-configured accelerator that communicates with a second communication device by a communication frame containing information necessary for executing software that implements a part of the PON function Second communication device: A communication device that executes the software The station-side terminating device and the first communication device,
The PON system according to claim 1, comprising pluggable modules each directly connected to said concentrator. The first communication device and the second communication device are
3. The PON system according to claim 1 or 2, comprising pluggable modules directly connected to said concentrator respectively. Said software includes:
an application component for realizing the partial function, and a common function unit connected to the application component via an internal API,
The accelerator is
4. The PON system according to any one of claims 1 to 3, wherein the PON system comprises an FPGA that communicates with the common function unit using a function frame for transmitting function information required for the part of the functions. The application parts include:
5. The PON system according to claim 4, comprising a DBA application for realizing a DBA function for one or more subscriber-side terminal devices accommodated in said PON line. The application parts include:
6. The PON system according to claim 4 or 5, comprising a power saving application for implementing power saving functions for one or more subscriber-side terminal devices accommodated in said PON line. Said software includes:
an application component for realizing a predetermined service based on user data transmitted by a subscriber-side terminal device accommodated in the PON line;
The accelerator is
4. The PON system according to any one of claims 1 to 3, comprising an FPGA that executes determination processing required for said service using said user data and notifies said second communication device of a determination result. The user data is
image data output by a monitoring camera connected to the subscriber-side terminal device;
The application parts include:
Includes a security application to notify users of monitoring results,
The determination process is
8. The PON system according to claim 7, wherein the processing is to determine the state of a predetermined object included in said image data. A communication device directly or indirectly connected to a concentrator to which one or more station-side terminal devices that terminate corresponding PON lines are directly or indirectly connected,
A housing and a hardware-configured accelerator housed in the housing,
The accelerator is
a transmission/reception unit that receives a report defined below from the station-side terminating device, transmits a batch report defined below to another communication device, receives a batch gate defined below from the other communication device, and transmits a grant control frame defined below to the station-side terminating device;
a report processing unit that converts the received report into the batch report and inputs it to the transmission/reception unit;
and a gate processing unit that converts the received batch gate into the grant control frame and inputs the frame to the transmission/reception unit.
Report: Control frame in which only one requested transmission amount of the subscriber-side terminating device is stored Batch report: Control frame in which the requested transmission amount of the subscriber-side terminating device is stored collectively Batch gate: Control frame in which grant information of the subscriber-side terminating device is collectively stored Grant control frame: Control frame in which only one grant information of the subscriber-side terminating device is stored A communication device directly or indirectly connected to a concentrator to which one or more station-side terminal devices that terminate corresponding PON lines are directly or indirectly connected,
A housing and a hardware-configured accelerator housed in the housing,
The accelerator is
a transmission/reception unit that receives a bandwidth notification defined below from the station-side terminating device, transmits a collective bandwidth notification defined below to another communication device, receives a batch PS notification defined below from the other communication device, and transmits a sleep control frame defined below to the station-side terminating device;
a bandwidth notification processing unit that converts the received bandwidth notification into the batch bandwidth notification and inputs it to the transmission/reception unit;
a PS processing unit that converts the received collective PS notification into the sleep control frame and inputs the same to the transmission/reception unit.
Bandwidth notification: A control frame that stores only one piece of bandwidth information for a subscriber-side terminating device Batch bandwidth notification: A control frame that collectively stores bandwidth information for a subscriber-side terminating device Batch PS notification: A control frame that collectively stores sleep information for a subscriber-side terminating device Sleep control frame: A control frame that stores only one piece of sleep information for a subscriber-side terminating device

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