WO2022137286A1

WO2022137286A1 - Communication system, communication device, communication method, and program

Info

Publication number: WO2022137286A1
Application number: PCT/JP2020/047697
Authority: WO
Inventors: 學吉野
Original assignee: 日本電信電話株式会社
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2022-06-30

Abstract

One embodiment of the present invention is a communication system comprising: a distribution information notification unit whereby distribution information indicating a route for distributing data is input to a device to which the data is to be transmitted before the device to which the data is to be transmitted distributes the data to routes in which the wavelength, polarization, mode, frequency, code, core, fiber, or at least part of a combination thereof differs; and a data communication unit that is provided to the device to which data is to be transmitted and distributes the data in accordance with the input distribution information.

Description

Communication systems, communication devices, communication methods and programs

The present invention relates to a communication system, a communication device, a communication method and a program.

In recent years, due to the increase in content capacity and the increase in real-time services, network capacity increase and ultra-low latency are required. Therefore, in order to meet such demand, a communication technique having a larger communication capacity, such as an all-optical all-photonics network, has been proposed (Non-Patent Document 1).

However, the technologies proposed so far have been the VLAN ID (Identifier) of the VLAN tag specified in IEEE 802.1Q such as the destination address, port number, and VLAN (Virtual Local Area Network) included in the header of the packet. In some cases, the delay cannot be reduced when packet processing for reading and transferring information related to a destination such as VLAN) occurs in a switch such as a photonic gateway. The packet processing is, for example, error detection for each packet, processing for adding or deleting user information or destination information (information indicating a communication partner) included in each packet, and processing for storage and exchange.

In view of the above circumstances, it is an object of the present invention to provide a technique for reducing the time required for reading the destination of the storage and exchange.

One aspect of the invention is before the device to which the data is transmitted distributes the data to a path where at least a portion of the wavelength, polarization, mode, frequency, code, core, fiber, or combination thereof is different. The data transmission destination device is provided with a distribution information notification unit for inputting distribution information indicating a route for distributing the data, and the transmission destination device provided with the data according to the input distribution information. It is a communication system including a data communication unit for distributing data.

One aspect of the invention is before the device to which the data is transmitted distributes the data to a path where at least a portion of the wavelength, polarization, mode, frequency, code, core, fiber, or combination thereof is different. It is a communication device provided with a distribution information notification unit for inputting distribution information indicating a route for distributing the data to the device to which the data is transmitted.

One aspect of the present invention is information input before the data is distributed to a path in which at least a part of wavelength, polarization, mode, frequency, code, core, fiber, or a combination thereof is different. It is a communication device including a data communication unit for distributing the data based on the distribution information which is the information indicating the route of the distribution destination.

One aspect of the invention is before the device to which the data is transmitted distributes the data to a path where at least a portion of the wavelength, polarization, mode, frequency, code, core, fiber, or combination thereof is different. The data is provided with a distribution information notification step for inputting distribution information indicating a route for distributing the data to the device of the transmission destination of the data, and the data according to the input of the distribution information provided by the device of the transmission destination. It is a communication method having a data communication step for distributing.

One aspect of the present invention is a program for operating a computer as the above-mentioned communication system.

According to the present invention, it is possible to reduce the delay in communication.

An explanatory diagram illustrating the configuration of the communication system 100 of the first embodiment. The first explanatory diagram explaining the relationship between the data packet and the notification packet in 1st Embodiment. A second explanatory diagram illustrating the relationship between the data packet and the notification packet in the first embodiment. An explanatory diagram illustrating a delay in the communication system 100 of the first embodiment. An explanatory diagram illustrating a difference between the distribution processing of the switch 4 in the communication system 100 of the first embodiment and the prior art. The figure which shows an example of the hardware composition of OLT1 in 1st Embodiment. The figure which shows an example of the functional structure provided with the control part 11 in 1st Embodiment. The figure which shows an example of the hardware composition of the switch 4 of 1st Embodiment. The figure which shows an example of the structure of the control part 41 of 1st Embodiment. An explanatory diagram illustrating an example of a processing flow executed by the communication system 100 when there is FEC processing in the first embodiment. The flowchart which shows an example of the flow of the process executed by the communication system 100 of 1st Embodiment. The first explanatory diagram explaining an example of the flow of the notification to the switch 4 of the distribution information in 1st Embodiment. A second explanatory diagram illustrating an example of the flow of notification of distribution information to the switch 4 in the first embodiment. The first explanatory diagram explaining an example of the flow of the notification to the switch 4 of the distribution information in the modification of the 1st Embodiment. A second explanatory diagram illustrating an example of the flow of notification of distribution information to the switch 4 in the modified example of the first embodiment. Explanatory drawing explaining the outline of the communication system 100a of 2nd Embodiment. An explanatory diagram illustrating an example of a processing flow in which distribution information is notified to the switch 4 in the communication system 100a of the second embodiment.

(First Embodiment)
FIG. 1 is an explanatory diagram illustrating an outline of the communication system 100 of the first embodiment. The communication system 100 includes an OLT (Optical Line Terminal) 1, one or more ONUs (Optical Network Units) 2, an optical splitter 3, and one or more switches 4. The OLT 1 and each ONU 2 are communicably connected to each other via an optical splitter 3.

OLT1 is a subscriber line end station device. The OLT 1 is a device that communicates with another communication device (for example, ONU2) by a signal passing through the ODN communication network. The OLT 1 is connected to, for example, an ODN (Optical Distribution Network) and constitutes a passive optical communication network such as a PON (Passive Optical Network). Hereinafter, the case where the system configured by using OLT1 is PON will be described as an example, but other data may be a system for designating or reserving the time to be transmitted or reached. The OLT 1 is installed, for example, in a station building connected to a communication network.

ONU2 is a subscriber line termination unit (ONU: Optical Network Unit). The ONU2 is a device that realizes communication with another communication device by a signal passing through a communication network. The communication network to which ONU2 is connected is a passive optical communication network such as PON. The ONU2 is installed, for example, in the home of a user who receives a communication service. ONU2 may be a part of a device such as FTTH (Fiber to the Home) or FTTB (Fiber to the Building).

Each ONU2 is communicably connected to one or more user devices 9. The user device 9 is a device operated by the user. The user device 9 is used, for example, in the home of a user who receives a communication service. The user device 9 is a communicable information processing device such as a personal computer, a smartphone, a mobile phone, a tablet computer, a wireless LAN (Local Area Network) router, or a television receiver.

The optical splitter 3 merges the uplink signals transmitted from ONU2 and propagates to OLT1. The optical splitter 3 branches the downlink signal transmitted from the OLT 1 and propagates to the ONU 2. In addition, "up" means the direction from ONU2 to OLT1, and "down" means the direction from OLT1 to ONU2.

The switch (SW: Switch) 4 distributes data such as data packets. That is, the switch 4 switches, for example, an outgoing path for outputting data such as a data packet. The route may be a path in which at least a part of wavelength, polarization, mode, frequency, sign, core, fiber, or a combination thereof is different. SW means a switch.

In the conventional storage and exchange, information such as destination MAC (MediaAccessControl) address, destination IP (InternetProtocol) address, VID, etc. contained in the header of the packet is read and distributed accordingly.

In the communication system 100 of the first embodiment, the data is distributed to different paths at least a part of wavelength, polarization, mode, frequency, code, core, fiber, or a combination thereof at the transmission destination. Distribution information indicating the route for distributing data is notified to the transmission destination.

The distribution information is information related to the distribution destination of data arriving in time division multiplexing, and is information that links the arrival time of the data of the relevant route with the distribution destination / destination. The distribution information is calculated based on, for example, information that specifies, allocates, or reserves a time for transmitting or arriving data. The distribution information is, for example, a report for a transmission permission request such as DBRu (Dynamic Bandwidth Report upstream) included in the physical layer overhead (PLOu) of ONU Burst that constitutes a report packet or an uplink GTC (G-PON transmission convergence) frame. It may be calculated based on. The transmission permission request is information indicating that the transmission permission of the data packet is requested. The distribution information includes, for example, a calculated transmission permission such as a bandwidth map (BWmap) for notifying the uplink bandwidth allocation included in the Gate packet to be permitted to be transmitted and the PCBd (Physical Control Block Downstream) which is the header of the downlink GTC frame. It may be calculated based on the reservation information. Further, the distribution information may be calculated from such information. Such information means information for designating, allocating, or reserving a time for transmitting or arriving data, a declaration for a transmission permission request, and calculated transmission permission or reservation information.

In the following description, for the sake of simplicity, a more specific description of the communication system 100 will be given by taking the case where the transmission destination is the switch 4 as an example. The switch 4 receives a notification such as a notification packet before receiving the data packet, and according to the distribution information included in the notification, at least a part of the wavelength, the polarization, the mode, the frequency, the code, the core, the fiber, or a combination thereof is used. Distribute to different routes. For the sake of simplicity, the case where the notification is a notification packet so that the same transmission path as the data packet can be transmitted is described as an example, but the notification is a packet exchange if it is a signal for transmitting distribution information. It may be in a form other than a packet. The form other than the packet to be exchanged is, for example, a signal by circuit switching or a signal via a common signal line.

DBA when OLT1 processes DBA (Dynamic Bandwidth Assignment) will be described.
ONU2 declares the amount of accumulated uplink data to OLT1. Based on the declaration, OLT1 grasps the amount of uplink data stored in ONU2. The OLT 1 calculates the uplink band allocated to the ONU 2, for example, the uplink transmission start time and the transmission continuation time of the ONU 2, based on the amount of uplink data of the ONU 2 and the band used. The OLT 1 may calculate, for example, the time when the data arrives at the OLT 1 and the time when the transmission continues. OLT1 notifies ONU2 of the calculated value. ONU2 transmits the uplink data at the specified time according to the permission of the received notification. At this time, ONU2 may notify the amount of uplink data accumulated in the buffer again for the next bandwidth allocation.

The operation of DBA may be executed by a device other than OLT1. For example, a device including a functional unit that calculates a DBA outside the OLT1 may perform a DBA calculation, and a device including a functional unit that performs a DBA calculation outside the OLT1 may transfer the permission to the OLT1.

By utilizing the waiting time in the route for transmitting data according to the transmission permission or reservation after the transmission permission request or reservation is made, the distribution information is notified to the switch 4 in advance before the data packet arrives. The switch 4 is a transmission destination device for distributing data.

In order to notify in advance, a part of the routes constituting the route for transmitting data may be a route for transmitting data according to the transmission permission or reservation after making a transmission permission request or reservation. Therefore, some of the routes constituting the route for transferring data may be, for example, a PON section in which packets are multiplexed by time division multiple access.

Therefore, the distribution information may be generated after the functional unit that receives or generates the transmission permission or reservation information or the functional unit adjacent to the function unit receives the transmission permission request or reservation information. The distribution information may be generated after the transfer destination of the transmission permission request or the reserved information receives the transmission permission request or the reserved information.

The distribution information may be generated by, for example, a functional unit itself that generates a transmission permission by designating a time for transmitting or arriving data in a transmission line connected to OLT 1 or a transmission line connected to OLT 1, or a device including the functional unit.

The distribution information may be generated by, for example, the functional unit of the DBA. The distribution information may be generated by a functional unit of the DBA or an adjacent functional unit arranged in the arithmetic unit of the switch of the output destination, the equipment on the transmission line, or other equipment, such as the upper concentrating DBA.

The distribution information may be generated by, for example, a control device or an operation system that controls a plurality of devices. When the functional unit of the DBA or the adjacent functional unit generates the distribution information, the notification of the transmission permission notified to the ONU2 by the functional unit of the DBA or the functional unit that generates the adjacent distribution information may be duplicated. .. When the functional part of the DBA or the functional part that generates the adjacent distribution information generates the distribution information, the transmission permission information itself may be utilized, or the same declaration and use as used in the functional part of the DBA may be used. The notification of the transmission permission notified by the functional unit of the DBA may be estimated by the functional unit that generates the distribution information by using the situation, the set value, or the algorithm.

From the viewpoint of prompt generation and use, it is desirable to generate distribution information with a device located near the OLT1 that permits transmission and the switch 4 that is the transmission destination device for distribution. The device located in the vicinity of the switch 4 is, for example, a communication device having an arithmetic function for connecting to the OLT directly or via another SW4 or the like. Specific examples of such a communication device include SW4 and other OLTs. Further, the device located in the vicinity of the switch 4 may be a device for management and control, a device such as an operation system or a server, or an edge cloud. From the viewpoint of integrated processing in a plurality of devices, it is desirable that the distribution information is generated by a control device that controls a plurality of devices. When the switch 4 aggregates and distributes traffic from a plurality of devices and generates distribution information on its own switch, the distribution information is generated and used inside the switch 4.

The distribution information may include the data arrival time itself to the switch 4. The arrival time is calculated in consideration of the transmission delay from the OLT 1 to the device for distributing the data packet (here, the switch 4). The arrival time may be calculated proportionally by one or more of the notification source, the notification destination, and the device in the middle of the notification of the notification packet. When calculating at the notification destination, for example, when the transmission delay from OLT1 to the sorting device is constant, the transmission permission notification or the information is notified to the sorting device as it is, and the sorting device calculates it. You may.

The notification destination is a device that transmits the data, and is the OLT1 of the transmission destination. The OLT1 at the transmission destination aggregates data from multiple, for example, different frequencies, polarizations, wavelengths, codes, modes, cores, and core wire inputs into a single output, or collects data from a single input, for example, differently. Frequency, polarization, wavelength, code, mode, core, core wire output, or multiple, for example, different frequencies, polarization, wavelength, code, mode, core, core wire input, data from multiple, for example, different frequencies. It is distributed to the output of the polarization, frequency, code, mode, core, and core wire.

The device in the middle of the notification is, for example, a communication device located in front of the transmission line, for example, a switch 4, for example, a device for management and control, an operation system, or a server. The device in the middle of the notification may transmit the acquired distribution information to the next-stage device, or may transmit it to all the devices in the next-stage and subsequent stages.

In order to acquire and notify the distribution destination before the transmission of the data packet, the OLT1 associates, for example, the declaration source or the declaration unit with the destination or the distribution destination. The linking is, for example, the declaration unit at the time of request for transmission permission or reservation, path information representing the sender, link information, LLID (Logical Link ID), ONU-ID, T-CONT (Transmission Container) ALLOC-ID ( Either Allocation Identifier) or GEM (GPON Encapsulation Method) Port ID may be used. The linking is explicit destination information at the time of transmission permission request or reservation, for example, any tag defined between ONU2 and OLT1, or destination MAC address, destination IP address, destination or source IP address and destination. Alternatively, it may be used as data by transmitting any of a combination of source port numbers, VID, priority, and the like. The association may be used by learning or snuffing the history of past distributions, the destination estimated from the frame length, and the control in the upper layer. The destination estimated from the frame length is a case where a jumbo frame is used only with a specific destination in file transfer or the like, or a case where a short packet is used as a destination used for a call or the like. The control in the upper layer is a video-on-demand, a channel request for video distribution, a response thereof, and the like. The information for acquiring these distribution destinations is collectively referred to as tag information below.

Therefore, the distribution information is any one of path information, link information, ONU-ID, LLID, or GEMPORT ID representing the transmission source at the time of transmission permission request or reservation in at least a part of the route through which the data packet passes. Any or all or any of the explicit destination information, destination MAC address, destination IP address, combination of IP address and Port information or VID, past distribution information at the time of transmission permission request or reservation. You may use the combination of.

Here, the ONU-ID is an 8-bit identifier assigned to the ONU2 by the OLT1 during the activation of the ONU2 via a PLOAM (Physical Layer Operation, Administration and Maintenance) message. The ONU-ID is unique throughout the PON and is retained until the power supply to the ONU2 is cut off or deactivated by OLT1.

The ALLOC-ID is a 12-bit number that is assigned to ONU2 by OLT1 and identifies an entity carrying traffic that is a receiver of the uplink allocation in the ONU2. The entity that carries the traffic is sometimes referred to as the T-CONT. Each ONU2 is assigned a default ALLOC-ID equal to that ONU2's ONU-ID. An additional ALLOC-ID may be assigned by OLT1. If a plurality of items are assigned to each destination or distribution destination, the ALLOC-ID is associated with each.

T-CONT is an ONU object that represents a group of logical connections that are displayed as a single entity for the purpose of upstream bandwidth allocation in the PON.

GEM Port is a virtual port for executing GEM encapsulation when sending and receiving frames between OLT1 and ONU / ONT (Optical Network Termination). Different GEM ports are assigned to different traffic classes (TC: Traffic Class) for each OUN2. Each T-CONT is composed of one or more GEM ports. If multiple destinations and distribution destinations are configured, they will be linked to each.

LLID is an identifier used by ONU2 to determine whether the received frame is addressed to itself and to select the received frame. The identifier is overwritten by part of the preamble byte. A plurality of LLIDs may be associated with one ONU2. If you assign multiple destinations to each destination or distribution destination, they will be linked to each.

As described above, in the communication system 100, the delay time in the switch 4 is shorter than that of the storage-and-forward switch that reads information about the distribution destination from the overhead of the data packet after the data packet arrives. The delay time in the first embodiment is the time from when the switch 4 receives the data packet to when the distribution information is transmitted to the distribution destination without reading the distribution information from the data packet.

Since the communication system 100 of the first embodiment configured in this way notifies the distribution information to the switch 4 before receiving the data packet, the time required for the subsequent packet processing after the switch 4 receives the data packet is set. Can be mitigated. More specifically, the communication system 100 can reduce the time required for reading the destination after receiving the packet for storage and exchange. Therefore, the communication system 100 can reduce the delay in communication.

In the communication system 100 of the first embodiment configured in this way, the destination information of the data packet is acquired at the time of the declaration for receiving the transmission permission of the transmission line. Since the distribution destination is known in advance in this way, in the communication system 100, when distributing packets having different destinations, a process of reading and identifying the packet header or the like is executed by the transiting device each time. There is no need to.

That is, since the communication system 100 transmits the distribution destination known to the OLT 1 before the data transmission to the switch 4 in advance, the delay of distribution can be concealed by using the delay of TDMA. As a result, the communication system 100 can reduce the delay related to the distribution of the packet by the switch even when the packet is transmitted. Note that concealing the delay means reducing the delay time at the time of distribution by utilizing the delay time that always occurs.

Note that the user device 9 or ONU2 declares a transmission permission request, or in addition to the declaration, also declares information about the distribution destination and the like. The information regarding the distribution destination added to the declaration is, for example, tag information or destination information. The declaration may be piggy-packed into a data packet that has already been permitted to be transmitted and transmitted, or may be transmitted as a single unit with permission to be transmitted. The same is true for tokens.

The notification packet and the data packet may be transmitted by the same route or may be transmitted by different routes. This will be described with reference to FIGS. 2 and 3.

FIG. 2 is a first explanatory diagram illustrating the relationship between the data packet and the notification packet in the first embodiment. More specifically, FIG. 2 is a diagram showing an example of the relationship between the data packet and the notification packet when the data packet and the notification packet are transmitted on the same transmission line. When transmitted on the same transmission line, the notification packet arrives before the arrival at the beginning of the data packet in the communication system 100.

FIG. 3 is a second explanatory diagram illustrating the relationship between the data packet and the notification packet in the first embodiment. More specifically, FIG. 3 is a diagram showing an example of the relationship between the data packet and the notification packet when the data packet and the notification packet are transmitted on different transmission lines.

When transmitted on different transmission lines, it is sufficient that the notification packet arrives before the arrival of the main part of the data packet, and the distribution information of the packet can be read and distributed. Therefore, the arrival of the non-main part such as the preamble added / deleted on the transmission path to the data packet and the distribution information of the data packet of the notification packet may overlap in time. In FIG. 3, the first transmission line is a transmission line for transmitting a notification packet, and the second transmission line is a transmission for transmitting a data packet. FIG. 3 shows an example in which the arrival of the distribution information (distribution information regarding the data packet) included in the notification packet coincides with the arrival of the data packet in time.

If the switch 4 that has received the notification packet takes time to acquire the distribution information indicated by the notification packet (hereinafter referred to as "reading"), the notification packet arrives at the switch 4 before the limit time. You need to be. The limit time is a time before the arrival time of the data packet by the time (reading time) required to read the distribution information and reflect it in the distribution. If it takes time to calculate the arrival time of the data packet included in the distribution information, or to convert tags related to the distribution destination into information used for actual distribution, that time, FEC (Forward Error Correction) : When decoding a code such as (forward error correction) or decrypting the code, that time is also included in the read time.

FIG. 4 is an explanatory diagram illustrating reduction of delay in ONU2, OLT1 or a plurality of switches 4 of the communication system 100 of the first embodiment. A partial configuration of the communication system 100 is described on the upper side of FIG. 4, and a graph showing the relationship between the distance and the delay is described on the lower side of FIG. Here, the OLT 1 includes a DBA execution unit 101 as a functional unit of the DBA. Further, the DBA execution unit 101 generates distribution information in addition to the DBA.

In the graph of FIG. 4, the alternate long and short dash line notifies the switch 4 of the delay of the prior art in which the switch 4 reads the distribution destination from the arrived data packet, and the two-dot chain line notifies the switch 4 of the distribution information before the arrival of the data packet. Represents the delay of the technique in the first embodiment of the communication system 100 to be executed.
For example, for delay addition other than propagation delay, when ONU2 waits for transmission in DBA for 1 millisecond, switch 4 reads 100 bytes, distribution, transmission line band is 10 Gbit / s, and switch 10 stages, 100 [B]. ] × 8 [bit / B] × 10 [stage] ÷ 10 ¹⁰ [bit / s] ≈ 1 millisecond, which is a total of 2 milliseconds.

As shown in FIG. 4, in the technique of the first embodiment (that is, the communication system 100), the delay in each switch 4 is reduced as compared with the conventional technique. This is because the distribution information is notified to the switch 4 before the arrival of the data packet.

In the technique of the first embodiment, the process of calculating the distribution information and the process of notifying the calculated distribution information to reach the switch 4 are executed in the packet transmission processing time. The distribution information is notified at each switch 4 so that the data packet arrives at each switch 4 at least the read time before the data packet arrives at the switch 4. The packet transmission processing time is that after ONU2 declares, ONU2 is given transmission permission, ONU2 transmits a data packet according to the transmission permission, the data packet arrives at OLT1, and the data packet from OLT1 is sent to switch 4. It means the time to arrive. Therefore, the packet transmission processing time will be different for each switch 4. Since the distribution information is notified before the arrival of the data packet, each switch 4 does not need time to read the destination information from the data packet. The distribution unit 400 in FIG. 4 is a communication interface for distributing data packets to the distribution destination route.

FIG. 5 is an explanatory diagram illustrating a difference between the distribution processing of the switch 4 and the conventional technique in the communication system 100 of the first embodiment. FIG. 5 shows the time series of processing in order from the top. In each case, the processing with "None" at the end of the processing is not included. That is, the prior art includes packet storage, header analysis after packet arrival, and distribution processing based on the analysis, and the technique of the embodiment includes distribution information reception and distribution processing after packet arrival.

In the prior art, the switch accumulates packets to wait for header analysis, then analyzes the header, and determines the distribution destination based on the result of the header analysis. In the header analysis, the information recorded in advance is read in the form of a table or the like, and the header is analyzed using the read result. The switch distributes the data packet to the distribution destination based on the analysis result. When header analysis is performed during packet reception, if the information used for distribution is ONU-ID, T-CONT, GEM-PORT, LLID, after receiving FCS, if VID, after receiving 802.1Q header. If it is the destination MAC address used in the cut-through ether switch or the like, the header is analyzed after receiving the destination MAC address until after it is received.

On the other hand, in the communication system 100, the switch 4 receives the notification of the distribution information. The switch 4 reads the information regarding the distribution destination of the data packet from the distribution information. When the data packet arrives, the switch 4 distributes the data packet to the distribution destination of the data packet. That is, there is no packet accumulation waiting for header analysis, header analysis after the packet arrives, and distribution based on header analysis. Instead, there is reception of distribution information and distribution based on distribution information.

Note that the communication system 100 may generate distribution information by using the transmission reservation information instead of using the transmission permission information by the DBA. The reservation information may be extracted from a token or the like that notifies the reservation information, or may be added to a place where the packet can be added, such as Reserve of a packet used for other purposes. However, if the distribution destination is unknown from the DBA declaration, reservation information, etc., or if the distribution destination cannot be estimated from the sender information, etc., the location that can be added in the information transmission packet, etc., such as the declaration, etc. Needs to be changed to specify the destination or distribution destination.

FIG. 6 is a diagram showing an example of the hardware configuration of the OLT 1 in the first embodiment.
The OLT 1 includes a control unit 11 including a processor 91 such as a CPU (Central Processing Unit) connected by a bus and a memory 92, and executes a program. The OLT 1 functions as a device including a control unit 11, an OLT communication unit 12, and a recording unit 13 by executing a program.

More specifically, the OLT 1 reads the program recorded in the recording unit 13 by the processor 91, and causes the memory 92 to record the read program. When the processor 91 executes the program recorded in the memory 92, the OLT 1 functions as a device including the control unit 11, the OLT communication unit 12, and the recording unit 13.

The control unit 11 controls the operation of each functional unit included in the OLT1. The OLT communication unit 12 includes a communication interface for connecting the OLT 1 to an external device. The OLT communication unit 12 communicates with an external device via wired or wireless. More specifically, the OLT communication unit 12 includes an OLT first communication unit 121, an OLT second communication unit 122, and an OLT third communication unit 123. The OLT 2nd communication unit 122 and the OLT 3rd communication unit 123 are connected to, for example, a transmission line for transmitting the notification packet and the data packet of FIG.

The OLT second communication unit 122 is connected to, for example, the first transmission in FIG. 3, and the OLT third communication unit 123 is connected to, for example, the second transmission line in FIG. The OLT 2nd communication unit 122 and the OLT 3rd communication unit 123 may transmit notifications other than packets and data according to their respective formats. The OLT 2nd communication unit 122 and the OLT 3rd communication unit 123 do not need to be mounted as different devices, and may be mounted as one device. For example, it is implemented as a different device when there is a time when the notification packet and the data packet arrive at the same time as shown in FIG. 3, or when the notification is in a form other than the packet. It is not necessary to implement it as a different device when the notification is transmitted as a notification packet on the same transmission line as the data packet as shown in FIG.

The OLT 1st communication unit 121 includes a communication interface for connecting to the optical splitter 3. The OLT first communication unit 121 communicates with the ONU 2 via the optical splitter 3. The OLT 1st communication unit 121 receives, for example, a declaration from ONU2, and notifies ONU2 of a signal permitting transmission of the declaration and data.

The OLT second communication unit 122 includes a communication interface for connecting to the switch 4. The OLT second communication unit 122 notifies the switch 4 by communicating with the switch 4. That is, the OLT second communication unit 122 notifies the switch 4 of the distribution information.

The OLT 3rd communication unit 123 includes a communication interface for connecting to the switch 4. The OLT third communication unit 123 communicates with the switch 4 via the transmission line. The OLT third communication unit 123 sends and receives data packets to and from the switch 4.

The recording unit 13 is configured by using a readable recording medium device such as a magnetic hard disk device or a semiconductor recording device. The recording unit 13 records various information about the OLT 1. The recording unit 13 records in advance, for example, a program for controlling the operation of each functional unit included in the OLT1. The recording unit 13 records, for example, the relationship between the distribution information and the distribution destination, for example, the relationship between the tag information such as the ID on the ONU2 side and the distribution information. The recording unit 13 records, for example, destination information. The recording unit 13 records various information used for generating distribution information based on destination information, such as information of each switch 4 included in the communication system 100.

FIG. 7 is a diagram showing an example of the functional configuration included in the control unit 11 in the first embodiment. The control unit 11 includes a transmission permission notification unit 110, a declaration reception unit 111, a scheduler 112, and a distribution information notification unit 113. Here, in the first embodiment, unlike the embodiment described later shown in FIGS. 12 and 15, the distribution information does not have to be notified to the distribution device located at the subsequent stage in the transmission line. The notification unit 113 does not necessarily have to be provided. Also in the embodiment described later shown in FIGS. 12 and 15, the last switch and the OLT1 do not necessarily have to be provided with the distribution information notification unit 113.

The transmission permission notification unit 110 transmits a transmission permission request and a signal permitting transmission of a data packet to ONU2 via the OLT first communication unit 121.

The declaration receiving unit 111 receives the declaration output by ONU2 via the OLT first communication unit 121.

The scheduler 112 includes a distribution information generation unit 102 and a transmission permission calculation unit 103. The distribution information generation unit 102 generates distribution information based on the tag information and transmission permission. The transmission permission calculation unit 103 calculates the time at which the ONU 2 is permitted to transmit the data packet and the time at which the transmission is continued. The scheduler 112 corresponds to, for example, the DBA execution unit 101.

The time may be included in the distribution information. When included, the time may be the time when the data is transmitted, the time when the data arrives at the OLT, or the time when the data is transmitted from the OLT. In this case, the device that receives the distribution information may add the time that is transmitted from that time to the device that receives the distribution information to the time included in the distribution information. Further, the data may be the time when the data arrives at each device of the transmission destination. That is, the time included in the distribution information indicates the time when the data permitted to be transmitted arrives at OLT1, the time when the time for transmission from OLT1 to each switch 4 is added, and the time after the transmission delay of the data packet. It may be information (hereinafter referred to as "arrival time information"). In this case, the device that receives the distribution information uses the time as it is. In the case of the embodiment described later shown in FIGS. 12 and 15, the OLT 1 transmits at the time when it arrives at the frontmost device on the transmission line, that is, the switch 4 connected to the OLT 1 via the transmission line, and each switch 4 transmits. , The time included in the received distribution information may be notified as the time obtained by adding the time for arriving at the switch 4 which is the next device after arriving at the device, or the time when the OLT 1 is issued. Then, the time of arrival at the own device may be read and used by each switch 4, including the time of arrival at each switch 4.

When the data packet arrives after a predetermined time, the distribution information notification unit 113 does not have to transmit the arrival time information. When arriving after a predetermined time, the distribution information notification unit 113 does not have to transmit the arrival time information. The distribution information notification unit 113 transmits, for example, so that the difference between the notification packet arrival time and the data packet arrival time is constant, and distributes the data packet as arrival after the fixed time. The propagation delay includes a delay time such as error correction processing that occurs in each device existing between the switch 4 and the like and the OLT 1 when another device is included between the switch 4 and the like. The notification packet arrival time is the time when the notification packet arrives. The data packet arrival time is the arrival time of the data packet.

In this way, the sorting device, for example, the switch 4, sorts and then transfers the arrived data packet without reading the information about the destination described in the header of the data packet.

The distribution information notification unit 113 acquires distribution information. The distribution information notification unit 113 acquires, for example, the distribution information generated by the scheduler 112. The distribution information notification unit 113 may acquire distribution information from the sender or another device by using, for example, reservation information or tokens exchanged between the devices, and is shown in FIGS. 12 and 15. It may be acquired from a device in the previous stage on the transmission path as in the embodiment, or from a server such as a management device or an operation system as shown in FIGS. 13, 16 and 17.

The distribution information notification unit 113 notifies the distribution destination device of the distribution information. The destination for the OLT 1 is at least one switch 4 of one or more switches 4.

FIG. 8 is a diagram showing an example of the hardware configuration of the switch 4 of the first embodiment. The switch 4 includes a control unit 41 including a processor 93 such as a CPU connected by a bus and a memory 94, and executes a program. The switch 4 functions as a device including a control unit 41, a switch communication unit 42, and a recording unit 43 by executing a program.

More specifically, the control unit 41 reads the program recorded in the recording unit 43 by the processor 93, and causes the memory 94 to record the read program. When the processor 93 executes the program recorded in the memory 94, the switch 4 functions as a device including the control unit 41, the switch communication unit 42, and the recording unit 43.

The control unit 41 controls the operation of each functional unit included in the switch 4. The switch communication unit 42 includes a communication interface for connecting the switch 4 including the distribution unit 400 and the like to an external device. The switch communication unit 42 communicates with an external device via wired or wireless. An example of the external device to be communicated by the switch communication unit 42 is another switch 4 or OLT1.

The recording unit 43 is configured by using a readable recording medium device such as a magnetic hard disk device or a semiconductor recording device. The recording unit 43 records various information about the switch 4. The recording unit 43 records in advance, for example, a program for controlling the operation of each functional unit included in the switch 4. The recording unit 43 records, for example, distribution information or information indicating the relationship between the distribution information and the distribution destination.

FIG. 9 is a diagram showing an example of the configuration of the control unit 41 of the first embodiment. The control unit 41 includes a distribution information receiving unit 411. Here, in the first embodiment, unlike the embodiment described later shown in FIGS. 12 and 15, the distribution information does not have to be notified to the distribution device located at the subsequent stage in the transmission line. The notification unit 414 does not have to be provided. Also in the embodiment described later shown in FIGS. 12 and 15, the last switch and the OLT may not be provided with the distribution information notification unit 414.

By the way, in the communication system 100, the distribution information may be transferred from the switch 4 to the next switch 4. In the communication system 100, the distribution information may be corrected when transferred from the switch 4 to the next-stage switch 4, and then transferred, or when transferred from the switch 4 to the next-stage switch 4. May be generated in. In this way, the distribution information may be transmitted from the switch 4 to the next-stage switch 4 by transfer between the switches in the communication system 100. When the distribution information is transferred from the switch 4 to the next-stage switch 4 in this way, the control unit 41 may further include a distribution information notification unit 414.

The distribution information receiving unit 411 may receive distribution information via the switch communication unit 42 shown in FIG. 8, or may receive distribution information, or may use another transmission line other than that for sending and receiving data packets, for example, the switch 4. May be received via a transmission line for controlling.

The switch communication unit 42 transmits the data packet to be transmitted to the distribution destination switch 4 indicated by the distribution information according to the control of the control unit 41. When the FEC encodes information in block units and the encoded data packet is decoded by a decoder (DEC: Decoder) in the block unit, the switch communication unit 42 is a part of the data packet in block units to be decoded. May be accumulated and decoded. Even in this case, the delay in reading the packet header is reduced as compared with the conventional technique of reconstructing the packet after decoding, reading the header of the packet, and distributing the read information. The delay is similarly reduced for the GTC BIP (Bit Interleaved Parity) operation. The notification may be specified as the time after the propagation delay on the notification side, or may be read and distributed on the receiving side after the propagation delay.

FIG. 10 is an explanatory diagram illustrating an example of a processing flow executed by the communication system 100 when there is FEC processing in the first embodiment. FEC-DEC is a decoder of FEC. FEC-DEC decodes each block of the FEC-encoded packet in block units and connects the blocks to each other. FEC-DEC returns the encoded data packet to the original packet by connecting the blocks to each other, and reconstructs the packet.
In this case, the packet transmission processing time does not change, but it takes time to decode the FEC and reconstruct the packet, so the distribution information can be distributed before the packet is reconstructed by the distribution device. When the notification arrives, it is effective for the prior art of reading the header after reconstructing the packet.

Even if there is FEC processing, since the switch 4 acquires the distribution information before receiving the data packet, it can be distributed without reading the packet header after reconstructing the data packet. Therefore, the switch 4 can reduce the delay by at least the time for reading the packet header.

FIG. 11 is a flowchart showing an example of the flow of processing executed by the communication system 100 of the first embodiment. In FIG. 11, for the sake of simplicity of explanation, there is a case where the distribution information or the destination information is known from the transmission permission request itself, or a case where the distribution information or the destination information whose distribution destination can be identified is also added to the transmission permission request. An example of the processing flow will be described by taking the case where the switch 4 is one as an example.

The transmission permission notification unit 110 transmits a signal permitting the declaration of the transmission permission request to ONU2 according to the scheduler 112 (step S101). When step S101 is executed, ONU2 declares a transmission permission request to OLT1 (step S102). Following step S102, the OLT1 receives a transmission permission request (with destination information added) (step S103). The fact that the OLT 1 receives the transmission permission request (with the destination information added) specifically means that the declaration receiving unit 111 acquires the transmission permission request via the OLT communication unit 12.

Next, the scheduler 112 creates a schedule based on the transmission permission request (step S104). Specifically, the creation of the schedule calculates the time when the transmission of the data packet by the ONU2 is started by the DBA and the continuation time thereof, and the time when the data packet from the ONU2 starts to arrive at the OLT1 and the continuation time thereof. This means that the distribution information used for distribution when the data packet transmitted by the ONU 2 reaches the switch 4 is calculated.

Next, the distribution information notification unit 113 notifies the distribution information from the OLT 1 to the transmission destination switch 4 according to the scheduler 112 (step S105). Next, the distribution information receiving unit 411 included in the transmission destination switch 4 acquires distribution information via the switch communication unit 42 (step S106).

Next, the transmission permission notification unit 110 notifies ONU2 of the transmission permission of the data packet according to the scheduler 112 (step S107). The data packet transmission permission is the information calculated in step S104 indicating the time when the data packet transmission is started and the time when the data packet is continued, and the time when the data packet arrives at OLT1 and the continuation thereof. It means information indicating time. Next, ONU2 transmits a data packet to OLT1 (step S108). Following step S108, OLT1 receives the data packet transmitted by ONU2 (step S109).

Next, the OLT 1 transmits the data packet to the destination switch 4 (step S110). Next, the switch 4 receives the data packet (step S111). Next, the data packet transmission unit 413 of the switch 4 distributes the data packet according to the distribution information and transmits it to the transmission destination (step S112).

The order in which each process from step S105 to step S107 is executed may be any order as long as the process in step S106 is executed before the process in step S111 is executed. Each process from step S105 to step S107 may be executed in the order of, for example, step S105, step S106, and step S107. Further, step S105, step S107, and step S106 may be executed in this order. Further, step S107, step S105, and step S106 may be executed in this order.

Next, the communication system 100 will be described with respect to the case shown in FIG. 4 in which the distribution information is directly notified from the OLT 1 to the Q switches 4.

When the data packet passes through the Q switches 4 (Q is an integer of 1 or more) of the communication system 100 before the data packet is transmitted to the communication partner, each process of step S111 and step S112 is a switch of Q. 4 Each is executed sequentially. Specifically, when step S111 and step S112 are executed for the first switch 4, step S111 and step S112 are sequentially performed for the Q switches for the transmission destination switch 4 in step S112.

Not only steps S111 and S112, but also the distribution information generation process and the processes of steps S105 and S106 may be executed for each of the Q switches 4. The distribution information generation process is a process for generating distribution information among the processes executed in step S104. The process of generating the distribution information is specifically the process of calculating the distribution information in step S104. For each switch 4, the distribution information generation process, step S105, and step S106 may be executed in any order as long as step S106 is executed before step S111.

The distribution information generation process, step S105, and step S106 may be executed in the order of, for example, the distribution information generation process, step S105, and step S106. Further, the steps S105, the distribution information generation process, and the step S106 may be executed in this order. Further, the steps S106, the distribution information generation process, and the step S105 may be executed in this order. Further, for example, it may be executed for the switch 4 in the subsequent stage before the switch 4 in the previous stage.

As described above, the OLT 1 is a communication device that notifies the transmission permission of the data packet and the distribution information of the data packet at the destination in advance before receiving the data packet at the destination of the data packet.

Therefore, the OLT 1 in the first embodiment configured in this way can reduce the time required for reading the destination at the time of storage and exchange, which occurs in the communication system 100.

Further, since the communication system 100 of the first embodiment includes the OLT 1, the time required for reading the destination at the time of storage and exchange can be reduced.

FIG. 12 is a first explanatory diagram illustrating an example of a flow of notification of distribution information to the switch 4 in the first embodiment. FIG. 12 shows that distribution information is transferred from the switch 4 to the switch 4 for the switch 4 other than the switch 4 in the next stage of the OLT 1. The communication system 100 will be described with respect to the flow of notification of distribution information shown in FIG.

When the data packet passes through the Q switches 4 of the communication system 100 before the data packet is transmitted to the communication partner, the processes of steps S105 and S106 and the processes of steps S111 and S112 are Q. It is executed sequentially by each of the switches 4 of.

Specifically, when steps S105 and S106 are executed for the first switch 4, steps S105 and S106 are sequentially performed for the Q switches for the transmission destination switch 4 in step S106. When steps S111 and S112 are executed for the first switch 4, steps S111 and S112 are sequentially performed for the Q switches for the transmission destination switch 4 in step S112.

However, in step S105 other than the first switch 4, the switch 4 in the previous stage notifies the distribution information instead of the OLT1. The first switch 4 means the switch 4 in the next stage of the OLT1. The distribution information generation process may also be executed for the remaining (Q-1) switches 4 other than the last switch 4.

Each switch 4 may transfer the received distribution information, or may partially modify the received distribution information. For example, each switch 4 may postpone the time when the data to be distributed by the transmission delay between the previous stage and the next stage switch 4 arrives. Each switch 4 adjusts the change in the delay time when the delay time increases or decreases due to the conflict between data packets in the switch 4 in the previous stage, the conflict in the task in the calculation function, or the switching of the task or the memory. May be good.

The distribution information generation process is executed only by OLT1 or only by OLT1 and the first switch 4, and the switch 4 sent to the switch 4 in the subsequent stage partially corrects the distribution information of its own device. It may be transmitted to the switch 4 in the subsequent stage. The scheduler 112 may receive information such as a declaration used for the DBA and generate distribution information at each switch 4. The order of step S106 and steps S104 and S105 for each switch 4 may be executed in any order as long as step S106 is executed before step S111 for each switch 4.

As described above, the switch 4 provided with the switch 4 in the subsequent stage at the transmission destination is a communication device that notifies the distribution information of the data packet at the destination in advance before receiving the data packet at the destination of the data packet.

Therefore, the OLT 1 and the switch 4 for notifying the distribution information to the switch 4 in the subsequent stage in the first embodiment configured in this way reduce the time required for reading the destination at the time of storage and exchange that occurs in the communication system 100. Can be done.

Further, since the communication system 100 of the first embodiment includes the OLT 1 and the switch 4 for notifying the distribution information to the switch 4 in the subsequent stage, it is possible to reduce the time required for reading the destination at the time of storage and exchange.

FIG. 13 is a second explanatory diagram illustrating an example of the flow of notification of distribution information to the switch 4 in the first embodiment. FIG. 13 shows that at least the distribution information notified to the switch 4, which is the first transmission destination of the OLT 1, is generated by an external device of the OLT 1. In FIG. 13, the external device is the management device 5. The communication system 100 will be described with respect to the flow of notification of distribution information shown in FIG.

In the case of FIG. 13, regarding the generation of transmission permission or distribution information in step S104, an external device may execute both transmission permission and generation. The OLT1 may generate either the transmission permission or the distribution information, and an external device may generate the other. For example, the OLT 1 executes a process of generating a transmission permission in step S104 and a process of transferring the generated transmission permission to an external device that generates distribution information, and the external device performs the process of transferring the distribution information in step S104. May be executed. The reverse is also possible.

The transmission permission request received in step S103 is transferred to an external device that generates distribution information, step S104 is executed by the external device, and the generated transmission permission and distribution information are transferred to OLT1. OLT1 may perform steps S105 and S107. The OLT transfers the transmission permission request received in step S103 or the transmission permission generated by executing as part of step S104 to an external device, and the external device generates distribution information in step S104. It may be executed to transfer the distribution information to the OLT1 so that the OLT1 may execute steps S105 and S107. The OLT transfers the transmission permission request received in step S103 or the transmission permission generated by executing as part of step S104 to an external device, and the external device generates distribution information in step S104. It may be executed by an external device to execute step S105 and OLT1 to execute step S107.

As described above, the external device that implements step S104 notifies the destination of the data packet of the distribution information of the data packet directly or via OLT1 before the destination of the data packet receives the data packet. It is a communication device.

Therefore, the external device that implements step S104 in the first embodiment configured in this way can reduce the time required for reading the destination at the time of storage and exchange, which occurs in the communication system 100.

(Variation example of the first embodiment)
The method of receiving the distribution information by each switch 4 may be any method as long as the distribution information can be received by each switch 4 before the data packet is received for each switch 4. good. The method of receiving the distribution information by each switch 4 may be, for example, a method in which the distribution information is directly transmitted from the OLT 1 to each switch 4 (hereinafter referred to as “OLT instruction method”). An example of the OLT instruction method is the method shown in FIG. The method of receiving the distribution information by each switch 4 may be, for example, the method shown in FIG. 12 (hereinafter referred to as “notification relay method”).

The notification relay method will be described with reference to FIG. FIG. 12 is also an explanatory diagram illustrating the notification relay method. As shown in FIG. 12, the notification relay method is a method in which the switch 4 that has received the distribution information transmits the distribution information to the switch 4 to which the data packet is transmitted by the switch 4 in the subsequent stage. In the case of the notification relay method, each switch 4 includes a distribution information notification unit 113, and the distribution information notification unit 113 transmits distribution information to the next switch 4.

The notification relay method is a case where data packets from a plurality of directions are transmitted to the switch 4 in the middle of the route, and the transmission times for the plurality of data packets overlap (that is, conflict or collision). In the case of deviation, the switch 4 has the effect of shifting the arrival time at the transmission destination switch 4.

FIG. 14 is a first explanatory diagram illustrating an example of the flow of notification of distribution information to the switch 4 in the modified example of the first embodiment. The difference between the method of FIG. 4 and the method of FIG. 14 is that the switch 4 returns a response to the notification of distribution information. Numerical values of "1 to N notification", "N + 1 response", "2N-2 response", "2N-1 response", "2N response" and "2N + 1 transmission permission" (that is, 1 to N, N + 1) shown in FIG. , 2N-2, etc.) indicate the order in which the notifications are given. The order in which the notifications are given in FIG. 14 is an example of the order in which the notifications are given. “Notification”, “response”, and “transmission permission” represent notification of distribution information, notification of response to receipt of distribution information, and notification of transmission permission, respectively.

The OLT 1 may notify the ONU 2 of transmission permission when all of the switches 4 on the path through which the packet is transmitted can perform distribution at the time when the packet is conducted. For example, among the ONU2s having uplink data, all of the switches 4 on the path for transmitting the packet notify the ONU2 capable of performing distribution at the time when the packet is conducted, and the path for transmitting the packet. ONU2, which cannot perform distribution at the time when all of the above switches 4 conduct the packet, is notified of the transmission permission at the time when it becomes possible. Alternatively, all of the switches 4 on the path through which the packet is transmitted reselect the path at which distribution can be performed at the time when the packet is conducted, and notify the transmission permission. In these cases, the time spent in the system after issuing the ONU can be reduced. When waiting until the former possible time after inputting to the ONU, the remaining amount of the allowable delay until the transmission is completed is a predetermined value, for example, the sum of the propagation delay and the delay due to sorting or waiting for multiple processing. Or, when the time is obtained by multiplying the sum by a coefficient, the transmission permission may be notified even if there is a wait due to distribution or multiplex processing.
The OLT1 may notify the ONU2 whether or not the distribution information is accepted at the time of notifying the response to the ONU2. By notifying acceptance / rejection, for example, it is possible to determine whether or not there is a delay due to multiplexing before transmission.

The OLT 1 may notify distribution information to a plurality of routes such as all candidates of the route through which the data packet propagates, and may select a route with many acceptance notifications as the distribution destination, or may accept the distribution. A route with less delay may be selected from the routes.

OLT1 may select a route with a small predicted delay. The delay may be caused by, for example, the number of configured traffics, or may be caused by the collision of the traffic having the same priority or the highest priority with the traffic permitted to be transmitted at the switch 4. Therefore, the OLT1 may select a route that is determined to have a small delay, for example because it is not prioritized. From the viewpoint of selecting a route and predicting the amount of delay, it is advisable to add the reservation status and the predicted delay information to the response to the notification of acceptance / rejection.

The method shown in FIG. 14 is effective when packet switching is executed, but it is also effective when path switching is executed. In path switching, unlike packet switching, routes, links, and lines are not shared and occupied by time division multiplexing as paths. In packet switching, the line is open except when communication is required, and the same line is shared by multiple people in a time-division manner.

In the case of path exchange, for example, data may be sent after all path settings to the destination are completed. In the case of path exchange, for example, data may be sent after the setting of all paths to the relay destination is completed. The relay destination is, for example, a photonic gateway (PhGW) constituting the all-photonics network of Reference 1, or a photonic cross-connect (PhXC) which is a device constituting an optical backbone medium network of the all-photonics network. In the case of path exchange, data may be sent after all path settings including them are completed. Specifically, they are a destination and a relay destination.

The transmission permission notification unit 110 of the OLT 1 or the control device does not give the transmission permission or suspends the transmission permission, and returns the response with the distribution information setting OK sequentially or in order from the destination to the transmission permission notification, and the response is received. You may allow the transmission after completion (when the pass reservation is successful). The response to the setting OK is a signal indicating that the setting is completed. This is also applicable to packet switching. In such a case, it is not necessary to provide a buffer for waiting for transmission due to storage-and-forward, collision, or conflict, except for ONU2, which is the transmission source.

FIG. 15 is a second explanatory diagram illustrating an example of the flow of notification of distribution information to the switch 4 in the modified example of the first embodiment. The difference between the method of FIG. 12 and the method of FIG. 15 is that the response to the notification of the distribution information is notified in the same manner as the difference between the method of FIG. 4 and the method of FIG. .. In FIG. 15, “1 notification”, “2 notification”, “3 notification”, “N notification”, “N + 1 response”, “2N-2 response”, “2N-1 response”, “2N response” and “2N + 1 response”. The numerical value of "transmission permission" (that is, 1, 2, 3, N, N + 1, 2, N-2, etc.) means the order in which notifications are performed. “Notification”, “response”, and “sending permission” represent the processing of notification of notification, notification of response, and notification of transmission permission, respectively.

(Second Embodiment)
The distribution information is, for example, when the communication system 100 includes a management device 5 for managing the distribution information, it is not necessarily a signal output by the OLT 1 and the signal received by the switch 4 does not have to be indicated. When the communication system 100 includes a management device 5 that manages distribution information, the distribution information may be transmitted to the switch 4 by the management device 5 that manages the distribution information. The communication system 100 including the management device 5 for managing the distribution information will be described in detail as the communication system 100a of the second embodiment.

FIG. 16 is an explanatory diagram illustrating an outline of the communication system 100a of the second embodiment. The communication system 100a includes an OLT 1, a plurality of ONUs 2, an optical splitter 3, a plurality of switches 4, and a management device 5. Hereinafter, those having the same functions as the functional unit included in the communication system 100 will be designated by the same reference numerals as those in FIGS. 1 or 6 to 9, and the description thereof will be omitted.

The management device 5 is a device different from the OLT1 and is a device that notifies the ONU2 facing the OLT1 of the transmission permission and the switch 4 of the distribution information. As described above, the management device 5 is a device different from the OLT 1 and is a device that manages the directions of the OLT 1 and each switch 4. Managing the route means determining the transmission start time, the arrival time at the OLT, the time for the transmission to continue, and the transmission destination for each of the OLT 1 and each switch 4.

The management device 5 acquires destination information from the user device 9 or ONU2. The management device 5 includes a control unit 51 including a CPU and a memory, an ONU2, an OLT1 and a switch 4, or an OLT1 and a switch 4, a management communication unit 52 capable of communicating, and a recording unit 53.

The management communication unit 52 includes a communication interface for connecting the management device 5 to the OLT 1 and the switch 4. The management communication unit 52 communicates with the OLT 1 and the switch 4 via wired or wireless. The management communication unit 52 is configured to include a communication interface for connecting the management device 5 to the ONU2 or connecting to the ONU2 via the OLT 1, and may communicate with the ONU2.

The control unit 51 controls the operation of each functional unit of the management device 5, including the control of the operation of the management communication unit 52. The control unit 51 includes a scheduler 112 and a distribution information notification unit 113. The management device 5 creates a schedule with the scheduler 112 based on the acquired declaration and destination information. The distribution information notification unit 113 notifies the OLT 1 and the switch 4 of the transmission permission and the distribution information generated by creating the schedule.

If the transmission permission is generated and notified by the OLT1 or other device and the distribution information notification unit 113 does not notify the transmission permission, the transmission permission notification unit may not be provided. However, in order to generate distribution information, the same transmission permission request declaration as the OLT1 or other device that generates the transmission permission, or a copy thereof or the generated transmission permission information is received.

The control unit 51 of FIG. 16 includes a declaration receiving unit, a transmission permission notification unit, and a distribution information notification unit similar to the control unit 11 of FIG. 7 instead of the distribution information notification unit 113, as shown in FIGS. 13 and 17. In addition, the declaration receiving unit receives the declaration of the transmission permission request or its duplicated or aggregated information from OLT1 or ONU2, the transmission permission notification unit notifies OLT1 or ONU2 of the transmission permission, and the distribution information unit transmits the distribution information. The switch 4 may be notified. Unlike FIGS. 13 and 17, when the transmission permission is not notified, the transmission permission notification unit may not be provided. However, in order to generate distribution information, the same transmission permission request declaration as the OLT1 or other device that generates the transmission permission, or a copy thereof or the generated transmission permission information is received.

The OLT 1 receives the transmission permission and the distribution information notified by the management device 5. The switch 4 receives the distribution information notified by the management device 5.

The timing of transmission of the distribution information by the management device 5 is the timing at which the distribution information can be received before the switch 4 receives the data packet.

After the transmission permission is acquired by the OLT1 and the distribution information is acquired by the switch 4, the same processing as the processing of steps S107 to S112 of FIG. 11 is executed.

The management device 5 is, for example, a CU (Central Unit) that is a mobile base station that schedules OLT in the optical mobile cooperation DBA (see Reference 1). The management device 5 may be, for example, a higher-level concentrating unit of the higher-level concentrating DBA. If the management device 5 is a CU, the DBA may be explicitly executed on the OLT and the transmission is permitted to the ONU, but the schedule information to the RU or the user device 9 is sniffed, and as a result, the OLT is changed to the ONU. You may allow transmission.

Reference 1: "Research and development of ultra-high-speed, low-power consumption optical network technology", [online], [Search on November 23, 2nd year of Reiwa], Internet <URL: https://www.soumu.go.jp /main_content/000424157.pdf>

Here, a first example of the flow of processing in which distribution information is notified to the switch 4 in the communication system 100a will be described with reference to FIG. 13. FIG. 13 is also an explanatory diagram illustrating a method in which the management device 5 notifies each switch 4 of distribution information in the communication system 100a of the second embodiment (hereinafter referred to as “management device notification method”). The difference between FIGS. 13 and 4 is that the management device 5 notifies the ONU 2 instead of notifying the ONU 2 of the transmission permission and the distribution information to the switch 4.

The management device 5 may acquire information required for calculating the transmission permission from the OLT1, ONU2, CU, RU or other devices by communication in order to notify the OLT1 of the transmission permission to the ONU2. The information required to calculate the transmission permission is, for example, information such as a declaration of a transmission permission request. In FIG. 13, the management device 5 may notify one switch 4 of the distribution information, and the remaining switches may acquire the distribution information by notification by the other switches 4, as in FIG. 12.

FIG. 17 is an explanatory diagram illustrating a second example of the flow of processing in which distribution information is notified to the switch 4 in the communication system 100a of the second embodiment. The relationship between FIGS. 13 and 17 is similar to the relationship between FIGS. 4 and 14. In FIG. 17, the numerical values (that is, 1 to N) of "permit transmission after response of 1 to N" and "notification of 1 to N, response" (that is, 1 to N) mean the order in which communication is performed. “Permission to send after response” and “notification, response” represent processing, notification, and response processing to be permitted to be transmitted after response, respectively. “Send permission after response” may be merely transmission permission. In FIG. 17, the management device 5 notifies one switch 4 of the distribution information and responds, and the remaining switches acquire the distribution information by notification from the other switches 4 and respond in the same manner as in FIG. May be good.

Since the communication system 100a of the second embodiment configured in this way includes a management device 5 that transmits distribution information before receiving the data packet, the switch 4 is required for subsequent packet processing after receiving the data packet. You can save time. More specifically, the communication system 100a can reduce the time required for reading the destination at the time of storage and exchange and the calculation at the time of storage and exchange. Therefore, the communication system 100a can reduce the delay in communication.

Further, since the communication system 100a of the second embodiment includes the management device 5, the time required for reading the destination at the time of storage and exchange can be reduced.

(Modification example common to the first embodiment and the second embodiment)
The communication system 100 and the communication system 100a may be implemented by using a plurality of information processing devices that are communicably connected via a network. In this case, each functional unit included in the communication system 100 and the communication system 100a may be distributed and mounted in a plurality of information processing devices.

The OLT 1 may be implemented by using a plurality of information processing devices connected so as to be communicable via a network. In this case, each functional unit included in the OLT 1 may be distributed and mounted in a plurality of information processing devices.

The management device 5 may be mounted by using a plurality of information processing devices connected so as to be communicable via a network. In this case, each functional unit included in the management device 5 may be distributed and mounted in a plurality of information processing devices.

All or part of each function of the communication system 100, the communication system 100a, the OLT1, and the management device 5 is hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array). It may be realized by using hardware. The program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a flexible disk, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, or a recording device such as a hard disk built in a computer system. The program may be transmitted over a telecommunication line.

It should be noted that all or part of each function of the communication system 100, the communication system 100a, the OLT1 and the management device 5 is composed of a combinational circuit realized by connecting a memory, for example, equivalent to a program stored in the memory and executed by the processor. The circuit that performs the processing may be configured and processed by hardware logic, or may be configured and processed by hardware logic without memory.

As described above, the OLT 1 is an example of a device that transmits distribution information to at least one switch 4 of one or a plurality of switches 4. Therefore, the OLT 1 is an example of a communication device including a distribution information notification unit. Further, the management device 5 is also an example of a communication device including a distribution information notification unit. The switch communication unit 42 is an example of a data communication unit. The switch 4 is also an example of a communication device including a distribution information notification unit.

The distribution information may include information indicating the time when the data packet arrives at the transmission destination device. Information indicating the time when the data packet arrives at the transmission destination device may be generated based on the distribution information. Therefore, the distribution information includes information indicating the time when the data packet arrives at the transmission destination device, and information indicating the time when the data packet arrives at the transmission destination device is generated based on the distribution information. It may have one or both properties of and.

Note that arrival is an expression seen from the signal, and reception is an expression seen from the switch 4. Therefore, the timing at which the signal arrives is the timing at which the switch 4 receives the arrival signal. The OLT data packet transmission unit 114 is an example of a data transmission unit. The data packet transmitted by the data transmission unit is an example of data. The scheduler 112 is an example of a distribution information acquisition unit. The switch 4 is an example of a communication device including a data communication unit.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and the design and the like within a range not deviating from the gist of the present invention are also included.

100, 100a ... communication system, 1 ... OLT, 2 ... ONU, 3 ... optical splitter, 4 ... switch, 5 ... management device, 101 ... DBA execution unit, 11 ... control unit, 12 ... OLT communication unit, 13 ... recording unit , 121 ... OLT 1st communication unit, 122 ... OLT 2nd communication unit, 123 ... OLT 3rd communication unit, 110 ... transmission permission notification unit, 111 ... declaration reception unit, 112 ... scheduler, 113 ... distribution information notification unit, 114 ... OLT data packet transmission unit, 102 ... distribution information generation unit, 103 ... transmission permission calculation unit, 41 ... control unit, 42 ... switch communication unit, 43 ... recording unit, 400 ... distribution unit, 411 ... distribution information Receiving unit, 414 ... Distribution information notification unit, 51 ... Control unit, 52 ... Management communication unit, 53 ... Recording unit, 9 ... User device, 91 ... Processor, 92 ... Memory, 93 ... Processor, 94 ... Memory

Claims

Before the device to which the data is transmitted distributes the data to a path where at least a part of the wavelength, polarization, mode, frequency, code, core, fiber, or a combination thereof is different, the device to which the data is transmitted is transmitted. In, a distribution information notification unit for inputting distribution information indicating a route for distributing the data, and
A data communication unit provided with the transmission destination device and distributing the data according to the input distribution information.
A communication system equipped with.
The distribution information is
Utilizing the time from when a transmission permission request or reservation is made to when the data is transmitted in at least a part of the route through which the data is passed, the transmission destination of the data is used before the data is distributed. Input to the device,
The communication system according to claim 1.
The distribution information is used in at least a part of the route through which the data is passed.
Either path information, link information, ONU-ID, LLID or GEM PORT ID indicating the sender at the time of transmission permission request or reservation, and explicit destination information, destination MAC address, destination at the time of transmission permission request or reservation. Includes one or both of an IP address, a combination of IP address and Port information, or a VID.
What is generated by learning past distribution information,
Has one or both properties of
The communication system according to claim 1 or 2.
The distribution information includes information indicating the time when the data arrives at the transmission destination device, and information indicating the time when the data arrives at the transmission destination device is generated based on the distribution information. Having one or both properties of being done,
The communication system according to any one of claims 1 to 3.
Before the device to which the data is transmitted distributes the data to a path where at least a part of the wavelength, polarization, mode, frequency, code, core, fiber, or a combination thereof is different, the device to which the data is transmitted is transmitted. In the distribution information notification unit, which inputs distribution information indicating the route for distributing the data.
A communication device equipped with.
Information that was input before the data was distributed to a path where at least a part of the wavelength, polarization, mode, frequency, code, core, fiber, or a combination thereof is different, and the path to which the data is distributed. Data communication unit that distributes the data based on the distribution information that is the information to be shown.
A communication device equipped with.
Before the device to which the data is transmitted distributes the data to a path where at least a part of the wavelength, polarization, mode, frequency, code, core, fiber, or a combination thereof is different, the device to which the data is transmitted is transmitted. In, a distribution information notification step for inputting distribution information indicating a route for distributing the data, and
A data communication step provided with the transmission destination device and distributing the data according to the input distribution information.
Communication method with.
A program for operating a computer as the communication system according to any one of claims 1 to 4.