JP7537600B2 - COMMUNICATION SYSTEM, COMMUNICATION METHOD, CONTROLLER AND PROGRAM - Google Patents

Description

The present disclosure relates to a communication system in which time division multiplexing networks are connected in multiple stages, a communication method therefor, a controller for controlling the same, and a program therefor.

In recent years, studies have been underway to accommodate multiple services and applications with various network requirements on the same network infrastructure. To achieve this, it is necessary to guarantee the quality required by each service or application accommodated on the same network in the end-to-end sections from "terminal to terminal" or "terminal to application server."

The end-to-end of a network can be divided into wireless and wired sections. In particular, in wireless sections, there is a priority control function called Enhanced Distributed Channel Access (EDCA) of IEEE 802.11 as an existing technology (see, for example, Non-Patent Documents 1 and 2).

IEEE 802.11e-2005 - IEEE Standard for Information technology--Local and metropolitan area networks--Specific requirements s--Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications - Amendment 8: Medium Access Control rol (MAC) Quality of Service Enhancements "IEEE802.11e: Wireless LAN standard for achieving QoS," Journal of the Institute of Image Information and Television Engineers, Vol. 57, No. 11 (2003) IEEE 802.3ah IEEE Standard for Information technology - Telecommunications and information exchange between systems - and metropolitan area networks - Specific requirements Part 3: Carrier Sense Multiple Access with Collision Detection (CS MA/CD) Access Method and Physical Layer Specifications Amendment: Media Access Control Parameters, Physical Layers, and Management Parameters for Subscriber Access Networks (http s://www.ieee802.org/21/doctree/2006_Meeting_Docs/2006-11_meeting_docs/802.3ah-2004.

EDCA is a terminal (destination)-based control, and it is difficult to control on a traffic flow basis, which would allow quality control on a service and application basis. However, by applying related technologies (see the "Appendix" below), it is possible to achieve quality control on a service and application basis.

The related technologies can be applied not only to wireless networks, but also to communication methods that use time division multiplexing, such as Passive Optical Networks (see, for example, Non-Patent Document 3). For example, as shown in Figure 1, the related technologies can be applied to a communication system that combines a wireless network section (for example, a wireless LAN) and a wired network section (PON).

On the other hand, when the related technology is applied to each section, packets may wait in the per-flow buffers of the terminal and ONU, as explained in Figures 2 and 3. Specifically, in networks #1 and #2, recording and scheduling are performed in the databases of the respective controllers (steps S02 and S12), but each controller performs scheduling for each network independently of the other. For this reason, a packet waiting time Tw occurs in the device at the connection point for each network (Tw increases in proportion to the number of stages in the network), and there is a possibility that end-to-end quality control cannot be achieved.

In FIG. 3, the steps are as follows:
Step S00: A packet is received from an application.
Steps S01 and S11: The amount of packets is notified.
Steps S02 and S12: Recording in the database and scheduling are performed.
Steps S03 and S13: The transmission time and the transmission amount are notified.
Steps S04 and S14: Transmission is performed according to the transmission time and transmission amount.
Steps S05 and S15: A transmission request is made.
Steps S06 and S16: Transmission is permitted.
Steps S07 and S17: The packet is transmitted.
Step S08: The packet is transmitted.
In other words, when the related technology is applied to a communication method using time division multiplexing, there is a problem that delay increases and bandwidth utilization efficiency decreases, making it difficult to implement desired quality control.

Therefore, in order to solve the above problem, the present invention aims to provide a communication system, communication method, controller, and program that can guarantee the bandwidth allocated to each traffic flow in a configuration in which time division multiplexing networks are connected in multiple stages.

In order to achieve the above objective, the communication system of the present invention takes into account the transfer time of each network connected in multiple stages by a single controller, and notifies the device connecting the networks in advance of the time at which it will send transferred flow-unit packets into the network.

Specifically, the communication system according to the present invention is a communication system having a plurality of time division multiplexing networks and a controller,
The network is connected in multiple stages,
The controller:
a database for storing communication times required for communication from a transmission request to permission to transmit and packet transmission for each of the networks;
a scheduler which, when transmitting a packet on a flow unit basis from any communication device included in any one of the networks, notifies the communication device of a transmission time for transmitting the packet, and notifies a connection device included in another of the networks connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the transmission time and the communication time of the other network;
The present invention is characterized by having the following.

A communication method according to the present invention is a communication method for controlling a time division multiplexing network connected in multiple stages, comprising the steps of:
storing communication times required for communication from a transmission request to transmission permission and packet transmission for each of the networks; and when transmitting a packet on a flow basis from any communication device included in any of the networks, notifying the communication device of a transmission time for transmitting the packet, and notifying a connection device included in another of the networks connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the transmission time and the communication time of the other network;
It is characterized by:

Furthermore, the present invention provides a controller for controlling a time division multiplexing network connected in multiple stages, comprising:
a database for storing communication times required for communication from a transmission request to permission to transmit and packet transmission for each of the networks;
a scheduler which, when transmitting a packet on a flow unit basis from any communication device included in any one of the networks, notifies the communication device of a transmission time for transmitting the packet, and notifies a connection device included in another of the networks connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the transmission time and the communication time of the other network;
The present invention is characterized by having the following.

The controller keeps track of the transfer time (the time from a transmission request to actually transmitting a packet) in each network, and when transmitting a packet from a network, it takes this transfer time into consideration and notifies the networks through which the packet passes and the network to which the packet is to be transmitted of the time to issue a transmission request for the packet. This allows permission to transmit the packet within the network before the packet arrives, so no waiting time Tw occurs in the device at the connection point for each network, and the packet can be transferred smoothly.

Therefore, the present invention can provide a communication system, communication method, controller, and program that can guarantee the bandwidth allocated to each traffic flow in a configuration in which time division multiplexing networks are connected in multiple stages.

The multiple networks may each be a PON (Passive Optical Network) and a wireless LAN (Local Area Network), the connection device of the PON may be an access point, and the connection device of the wireless LAN may be an ONU (Optical Network Unit).

The present invention is a program for causing a computer to function as the controller. The controller of the present invention can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network.

The above inventions can be combined as much as possible.

The present invention can provide a communication system, communication method, controller, and program that can guarantee the bandwidth allocated to each traffic flow in a configuration in which time division multiplexing networks are connected in multiple stages.

FIG. 1 is a diagram illustrating a problem to be solved by the present invention. FIG. 1 is a diagram illustrating a communication system in which time division multiplexing networks are connected. FIG. 11 is a sequence diagram for the uplink direction in a case where the related technology is applied to a communication system. FIG. 1 is a diagram illustrating a communication system according to the present invention. FIG. 1 is a diagram illustrating a communication system according to the present invention. FIG. 4 is a diagram for explaining information stored in a database possessed by a controller according to the present invention. FIG. 2 is a sequence diagram illustrating the operation of the communication system according to the present invention. 4 is a flowchart illustrating an operation of the communication system according to the present invention. FIG. 1 is a diagram illustrating a communication system according to the present invention. FIG. 1 is a diagram illustrating a communication system according to the present invention. FIG. 4 is a diagram for explaining information stored in a database possessed by a controller according to the present invention. FIG. 2 is a sequence diagram illustrating the operation of the communication system according to the present invention. 4 is a flowchart illustrating an operation of the communication system according to the present invention. FIG. 2 is a diagram illustrating a controller according to the present invention. FIG. 1 is a diagram illustrating a control system of the related art. FIG. 1 is a diagram illustrating a control system of the related art. FIG. 13 is a diagram illustrating a database provided in a controller of the related art. FIG. 1 is a diagram illustrating a control method of the related art. FIG. 1 is a diagram illustrating an effect of a control system according to a related art. FIG. 1 is a diagram illustrating the operation of a communication system according to a related art. FIG. 1 is a diagram illustrating a control system of the related art. FIG. 13 is a diagram illustrating a database provided in a controller of the related art. FIG. 1 is a diagram illustrating a control method of the related art. FIG. 1 is a diagram illustrating an effect of a control system according to a related art.

An embodiment of the present invention will be described with reference to the attached drawings. The embodiment described below is an example of the present invention, and the present invention is not limited to the following embodiment. Note that components with the same reference numerals in this specification and drawings are assumed to indicate the same components.

(Embodiment 1)
FIG. 4 is a diagram for explaining a communication system 301 of this embodiment. The communication system 301 has a plurality of networks (50#1, 50#2) of a time division multiplexing system and a controller 10. The network 50#1 is connected to a plurality of terminals 20 and a network upper device 30. The network 50#2 is connected to a plurality of network lower devices 40 and a network upper device 60. The network upper device 60 connects a higher-level network 70 such as the Internet to the network 50#2. The network upper device 30 is connected to one of the network lower devices 40 (network lower device 40#2 in FIG. 4), and enables communication between the network 50#1 and the network 50#2. The controller 10 is connected to each terminal 20, each network lower device 40, and the network upper device (30, 60). It is assumed that there are no network devices that communicate with each other than the devices shown in FIG. 4.

In Fig. 4, the solid lines indicate the communication of main signals, and the dashed lines indicate the communication of control signals. In Fig. 4, for the sake of simplicity, there are two networks 50, but the communication system according to the present invention can also be applied to a multi-stage connection of three or more networks.

FIG. 5 is a functional block diagram illustrating the functions of each device in the communication system 301.
The controller 10 is
a database 11 for storing communication times required for communication from a transmission request to permission to transmit and packet transmission for each network 50;
a scheduler 12 which, when transmitting a packet on a flow unit basis from any communication device (terminal 20 or network upper device 60) included in any one of the networks 50, notifies the communication device of a transmission time for transmitting the packet, and notifies a connection device (network lower device 40 or network upper device 30) included in another network connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the transmission time and the communication time of the other network;
has.

The controller 10 is assumed to have recorded in advance in the database 11 the time required from a transmission request to transmission permission and from a transmission request to packet transmission for each time division multiplexing network 50. The "required time" is, for example, the time from a packet transmission request made between the terminal 20 of network 50#1 and the network upper device 30 to packet transmission via packet transmission permission.

Figure 6 is a diagram explaining the information stored in database 11. Database 11 is divided into parts A and B, each of which holds the amount of packets per buffer and the "time required" for the network.

Each terminal 20 and network upper device 60 accumulates packets for each application in a per-flow buffer unit (25, 65). Then, each terminal 20 and network upper device 60 notifies the controller 10 of the amount of packets accumulated in the per-flow buffer unit (25, 65) at regular intervals as a control signal. Note that the per-flow buffer unit 25 of the terminal 20 may also be provided within the application 24.

The controller 10 records the notified packet volume. Based on this, the controller 10 determines the schedule of the highest-level network (network 50#2 in the case of Figures 4 and 5). Specifically, the controller 10 determines the transmission time and transmission volume at which the main signal transceiver unit 44 of the network lower-level device 40 transmits packets of each flow, and the request time at which the packet transmission request unit 42 makes a transmission request to the network upper-level device 60 from the control signal transceiver unit 41.

The controller 10 determines the schedule for the lower network 50#1 based on the stored communication time for the network 50#2 and the determined schedule for the network 50#2. Specifically, the controller 10 subtracts the communication time from the packet transmission time and transmission request time for the network 50#2 in the upstream communication, and adds the communication time to the packet transmission time and transmission request time for the network 50#2 in the downstream communication to determine the transmission time and transmission amount for transmitting packets of each flow in the network 50#1, and the request time for the packet transmission request unit 32 to request the terminal 20 to transmit from the control signal transmission/reception unit 31. When three or more networks are connected in multiple stages, the controller 10 repeats this operation.

The controller 10 determines the transmission time and transmission amount of the flow unit buffer units (25, 65) of each terminal 20 and the network upper device 60, and notifies them as control signals. In parallel with this, the controller 10 determines the transmission time of the packet transmission request units (32, 42) of the network upper device 30 and the network lower device 40, and notifies them as control signals.

Each terminal 20 and network upper device 60 transmits packets to the main signal buffer unit (26, 66) at the notified transmission time and transmission amount. The network upper device 30 and network lower device 40 transmit packet transmission requests to the terminal 20 and network upper device 60, respectively, at the notified request time.

Figure 7 is a sequence diagram explaining the operation of communication system 301. This sequence diagram explains the case of an upstream signal transmitting a packet from terminal 20 to network higher-level device 60. Note that among the step numbers used in Figure 7, the steps with the same step numbers used in Figure 3 are the same as the operations of the steps explained in Figure 3. Figure 8 is a flowchart explaining the operation of communication system 301. Each operation will be explained using Figures 7 and 8.

The communication method of the present embodiment is a communication method for controlling a time division multiplexing network connected in multiple stages,
storing a communication time required for communication from a transmission request to transmission permission and packet transmission for each of the networks (preliminary step); and when transmitting a packet on a flow basis from an arbitrary communication device included in any of the networks, notifying the communication device of a transmission time for transmitting the packet (step S03), and notifying a connection device included in another of the networks connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the sending time and the communication time of the other network (step S73);
It is characterized by:

[Upstream communication]
Step M01: The application 24 of the terminal 20 transmits a packet.
Step M02: The terminal 20 distributes the packets to the per-flow buffer units 25 (#1 to #L).
Step M03: This step corresponds to step S01. The packet amount notifying unit 22 of the terminal 20 notifies the controller 10 of the amount of packets stored in the per-flow buffer units 25 (#1 to #L) from the previous notification to the present.

Step C04: This step corresponds to step S02. The controller 10 records in the database 11 the amount of stored packets notified from each terminal 20.
Step C05: This step also corresponds to step S02. The scheduler 12 of the controller 10 determines the transmission time and the amount of packets of each flow in the highest network (network 50#2 in the configuration of FIG. 4) from the records in the database 11, and the issuance time of the transmission request issued by the packet transmission request unit 42.
Step C06: The controller 10 checks whether there is a network (a lower-level network connected to the time determination network) that is next higher than the network (hereinafter referred to as the "time determination network") that determined the packet transmission time and amount, and the time when the transmission request was issued.
Step C07: If there is a downstream network, the controller 10 performs the following calculation. The controller 10 subtracts the communication time of the time determination network recorded in the database 11 from the packet transmission time of each flow of the time determination network and the issuance time of the transmission request. The controller 10 then determines the subtracted values as the packet transmission time and amount of each flow in the upstream communication of the downstream network, and the issuance time of the transmission request. Then, step C06 is performed again.
Step C08: This step corresponds to step S03. If there is no lower network, the controller 10 notifies each terminal 20 in the lowest network (network 50#1 in FIG. 4) of the transmission time and amount of packets of each flow in the lowest network.
Step C09: This step corresponds to step S73. The controller 10 notifies the packet transmission request units 42 of each network connected in multiple stages from the lowest network to the highest network (each network from the network connected to the lowest network to the highest network; in the case of FIG. 4, network 50#2) of the issuance time of each transmission request.

Step M10: This step corresponds to step S04. The scheduler unit 23 of the terminal 20 transmits packets stored in each per-flow buffer unit 25 (#1 to #L) to the main signal buffer 26 according to the packet transmission time and amount notified by the controller 10. Thereafter, as described in FIG. 3, the terminal 20 and the network upper level device 30 perform steps S05 to S08.
Step Q11: This step corresponds to steps S74 and S15. The packet transmission request unit 42 of the network lower device 40 issues a transmission request to the network lower device 60 according to the issuing time notified by the controller 10. Although only the highest-level network 50#2 is shown in FIG. 7, the packet transmission request unit issues a transmission request to the higher-level device in each network from the network connected to the lowest-level network to the highest-level network. Thereafter, as explained in FIG. 3, the network lower device 40 and the network higher-level device 60 perform steps S16 to S17.

As explained above, the controller 10 schedules the terminal 20 and at the same time schedules and notifies the lower device 40 of the network 50#2 of a transmission request. This eliminates the need for the lower device to schedule after the packet arrives, by making a transmission request to a higher device in the network in advance and receiving transmission permission from the higher device. Therefore, the communication system 301 can efficiently transmit packets (upstream communication) even when multiple networks are connected in multiple stages.

[Downstream communication]
This operation is similar in the downstream direction.
Step N01: A packet is received from the upper network device 70.
Step N02: The network host device 60 distributes the packet to the per-flow buffer units 65 (#1 to #K).
Step M03: The packet amount notifying section 63 of the network host device 60 notifies the controller 10 of the amount of packets stored in the per-flow buffer sections 25 (#1 to #K) from the previous notification to the present.

Steps C04 to C06 and step C09 are as described above.
Step C07: The controller 10 performs the following calculation: The controller 10 adds the communication time of the time determination network recorded in the database 11 to the packet transmission time and the transmission request issuance time of each flow of the time determination network. The controller 10 then determines each of the sums as the packet transmission time and amount of each flow in downstream communication of the downstream network, and the transmission request issuance time.
Step C08: If there is no lower network, the controller 10 notifies the network host device 60 in the highest network (network 50#2 in FIG. 4) of the transmission time and amount of packets of each flow in the lowest network.

Step N10: The scheduler unit 62 of the network host device 60 transmits the packets stored in each per-flow buffer unit 65 (#1 to #K) to the main signal buffer 66 according to the packet transmission time and amount notified by the controller 10. Thereafter, downstream communication is performed in the opposite direction to the upstream communication in FIG.
Step P11: The packet transmission request unit 32 of the network upper level device 30 issues a transmission request to each terminal 20 according to the issuing time notified by the controller 10. Although only the highest level network 50#2 is shown in Fig. 7, the packet transmission request unit issues a transmission request to the lower level device in each network from the network connected to the lowest level network to the highest level network. After that, downstream communication is performed in the opposite direction to the upstream communication in Fig. 3.

As explained above, the controller 10 schedules the network upper device 60, and at the same time schedules and notifies the upper device 30 of the network 50#1 of a transmission request. This eliminates the need for the upper device to schedule after the packet arrives, by sending a transmission request to the lower device (terminal) in the network in advance and receiving transmission permission from the lower device (terminal). Therefore, the communication system 301 can efficiently transmit packets (downstream communication) even when multiple networks are connected in multiple stages.

(Embodiment 2)
Fig. 9 is a diagram for explaining a communication system 302 of the present embodiment. In the communication system 302, the network 50#2 is a PON (Passive Optical Network), the network 50#1 is a wireless LAN (Local Area Network), the network upper device 30 (connection device seen from the PON) is an access point 30a, the network lower device 40 (connection device seen from the wireless LAN) is an ONU (Optical Network Unit) 40a, and the network upper device 60 is an OLT (Optical Line Terminal) in the communication system 301 explained in Fig. 4.

A wireless LAN (e.g., Wi-Fi (registered trademark)) is a network in which time division multiplexing is applied to two-way communication between terminal 20 and access point 30a. A PON is a network in which time division multiplexing is applied only to communication from ONU 40a to OLT 60a. The controller 10 is connected to each terminal 20, access point 30a, and ONU 40a, and it is assumed that there are no other network devices with which it communicates.

Figure 10 is a functional block diagram explaining the functions of each device of the communication system 302. In the communication system 302, some of the functions of the network upper device 60 explained in Figure 5 (scheduler unit 62, packet amount notification unit 63, flow unit buffer unit 65, and main signal buffer unit 66) exist in the access point 30a.

It is assumed that the controller 10 has recorded in advance in the database 11 the communication times between the terminal 20 and the access point 30a, and between the OLT 60a and the ONU 40a.
11 is a diagram for explaining information stored in the database 11. The database 11 is divided into sections A and B, each of which holds the amount of packets per buffer and the "communication time" of the network.

Because the downstream signal in the PON section is not time-division multiplexed, each terminal 20 and access point 30a accumulates packets for each application in the per-flow buffer unit (25, 65). Then, each terminal 20 and access point 30a notifies the controller 10 of the amount of packets accumulated in the per-flow buffer unit (25, 65) at regular intervals as a control signal. Note that the per-flow buffer unit 25 may also be provided within the application 24.

The controller 10 records the notified packet volume. Based on this, the controller 10 determines the schedule of the highest PON section in the network. Specifically, the controller 10 determines the transmission time and transmission volume at which the main signal transceiver 44 of the ONU 40a transmits packets of each flow, and the request time at which the packet transmission request unit 42 makes a transmission request to the network upper device 60 from the control signal transceiver 41.

The controller 10 determines the schedule for the lower network 50#1 based on the stored communication time for the network 50#2 and the determined schedule for the PON section. Specifically, the controller 10 subtracts the communication time from the packet transmission time and transmission request time of the PON in upstream communication, and adds the communication time to the packet transmission time and transmission request time of the wireless LAN in downstream communication, thereby determining the transmission time and transmission amount of each flow in the next wireless LAN section, and the requested time for transmitting the transmission request.
It determines the transmission time and transmission amount of the per-flow buffer units (25, 65) of each terminal 20 and the access point 30a, and notifies them as control signals.
In parallel, the packet transmission request unit 42 of each ONU 40a determines a request time for transmission and notifies the ONU 40a of the time as a control signal.
Each terminal 20 and access point 30a transmits packets of the notified amount at the notified transmission time from the per-flow buffer unit (25, 65) to the main signal buffer unit (26, 66).
Each access point 30a and ONU 40a transmits a packet transmission request at the notified request time.

Figure 12 is a sequence diagram explaining the operation of the communication system 302. This sequence diagram shows the sequence when the controller 10 is notified by the terminal 20#N and the access point 20a#O' that packets have accumulated, and explains an example in which packets are transferred in both directions, up and down. Note that among the step numbers used in Figure 12, steps with the same step numbers used in Figures 3 and 7 are the same as the operations of the steps explained in Figures 3 and 7. Figure 13 is a flowchart explaining the operation of the communication system 302. Each operation will be explained using Figures 12 and 13.

[Upstream communication]
The operation of the upstream communication from the terminal 20 to the OLT 60a is the same as that described in the first embodiment (FIGS. 7 and 8), except for a part of the operation in the next step.
Step C05: In the first embodiment, the transmission time and amount of packets of each flow and the issuance time of a transmission request are determined for the highest-level network, but in this embodiment, the transmission time and amount of packets of each flow in the PON (50#2) and the issuance time of a transmission request issued by the packet transmission request unit 42 are determined.
Step C07: In the first embodiment, the time calculation is performed for the downstream network, but in this embodiment, the time calculation is performed for the PON. Specifically, the controller 10 subtracts the communication time of the PON recorded in the database 11 from the packet transmission time of each flow of the PON and the transmission request issuance time. The controller 10 then determines the subtracted values as the packet transmission time and amount of each flow in the upstream communication of the wireless LAN (50#1) and the transmission request issuance time.
Step C09: In the first embodiment, the lower level devices 40 of the networks connected in multiple stages are notified of the time of issuance of the transmission request, but in this embodiment, the ONUs 40a of the PON are notified of the time of issuance of the transmission request.
Furthermore, since only two networks, a PON and a wireless LAN, are connected, the loop of steps C06 and C07 is repeated only once.

In this embodiment, step V11 is performed instead of step Q11.
Step V11: This step corresponds to steps S74 and S15. The packet transmission request unit 42 of the ONU 40a issues a transmission request to the OLT 60a according to the issuing time notified by the controller 10. Thereafter, as described in FIG. 3, the ONU 40a and the OLT 60a perform steps S16 to S17.

As explained above, the controller 10 schedules the terminal 20 and at the same time schedules and notifies the ONU 40a of the PON 50#2 of a transmission request. By sending a transmission request to the OLT 60a in advance and receiving transmission permission from the OLT 60a, the ONU 40a does not need to schedule after the packet arrives. Therefore, the communication system 302 can efficiently perform packet transmission (upstream communication).

[Downstream communication]
This operation is similar in the downstream direction.
Step U01: This step corresponds to step S80. The access point 30a receives a packet from the PON 50#2.
Step U02: The access point 30a distributes the packet to the per-flow buffer units 65 (#1 to #K).
Step U03: This step corresponds to step S81. The packet amount notifying unit 63 of the access point 30a notifies the controller 10 of the amount of packets stored in the per-flow buffer units 25 (#1 to #K) from the previous notification to the present.

Steps C04 to C06 and step C09 are as described above.
Step C07: The controller 10 performs the following calculation: The controller 10 adds the PON communication time recorded in the database 11 to the packet transmission time and transmission request issuance time of each PON flow. The controller 10 then determines the sums as the packet transmission time and amount of each flow in the wireless LAN downstream communication, and the transmission request issuance time.
Step C08: This step corresponds to step S83. The controller 10 notifies the access point 30a of the wireless LAN of the transmission time and the amount of packets of each flow in the wireless LAN.

Step U10: This step corresponds to steps S84 to S87.
The scheduler unit 62 of the access point 30a transmits the packets stored in each per-flow buffer unit 65 (#1 to #K) to the main signal buffer 66 (step S84) according to the packet transmission time and amount notified by the controller 10. Thereafter, a transmission request (step S85) and transmission permission (step S86) are exchanged between the terminal 20 and the access point 30a, and the packets are transmitted from the access point 30a to the terminal 20 (step S87).

As described above, the communication system 302 can efficiently perform packet transmission (downstream communication).

(Embodiment 3)
The controller 10 can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a network.
14 shows a block diagram of a system 100. The system 100 includes a computer 105 connected to a network 135.

Network 135 is a data communications network. Network 135 may be a private or public network and may include any or all of the following: (a) a personal area network, for example covering a room; (b) a local area network, for example covering a building; (c) a campus area network, for example covering a campus; (d) a metropolitan area network, for example covering a city; (e) a wide area network, for example covering an area that crosses city, regional, or national boundaries; or (f) the Internet. Communications are conducted by electronic and optical signals over network 135.

Computer 105 includes processor 110 and memory 115 connected to processor 110. Although computer 105 is depicted herein as a stand-alone device, it is not limited to such, but rather may be connected to other devices not shown in a distributed processing system.

Processor 110 is an electronic device comprised of logic circuits that respond to and execute instructions.

The memory 115 is a tangible computer-readable storage medium on which a computer program is encoded. In this regard, the memory 115 stores data and instructions, i.e., program code, that can be read and executed by the processor 110 to control the operation of the processor 110. The memory 115 can be implemented as a random access memory (RAM), a hard drive, a read-only memory (ROM), or a combination thereof. One component of the memory 115 is the program module 120.

The program modules 120 include instructions for controlling the processor 110 to perform the processes described herein. Although operations are described herein as being performed by the computer 105 or a method or process or sub-process thereof, the operations are actually performed by the processor 110.

The term "module" is used herein to refer to a functional operation that may be embodied as either a stand-alone component or an integrated configuration of multiple subcomponents. Thus, program module 120 may be realized as a single module or as multiple modules operating in concert with one another. Furthermore, although program module 120 is described herein as being installed in memory 115 and thus implemented in software, it is possible for it to be implemented in either hardware (e.g., electronic circuitry), firmware, software, or a combination thereof.

Although the program module 120 is shown as already loaded into the memory 115, it may be configured to be located on the storage device 140 for later loading into the memory 115. The storage device 140 is a tangible computer-readable storage medium that stores the program module 120. Examples of the storage device 140 include compact disks, magnetic tapes, read-only memories, optical storage media, memory units consisting of a hard drive or multiple parallel hard drives, and universal serial bus (USB) flash drives. Alternatively, the storage device 140 may be a random access memory or other type of electronic storage device located in a remote storage system not shown and connected to the computer 105 via the network 135.

System 100 further includes data source 150A and data source 150B, collectively referred to herein as data sources 150, communicatively connected to network 135. In practice, data source 150 may include any number of data sources, i.e., one or more data sources. Data source 150 may include unstructured data and may include social media.

The system 100 further includes a user device 130 operated by the user 101 and connected to the computer 105 via a network 135. The user device 130 includes an input device, such as a keyboard or a voice recognition subsystem, to allow the user 101 to communicate information and command selections to the processor 110. The user device 130 further includes an output device, such as a display device or a printer or a voice synthesizer. A cursor control, such as a mouse, trackball, or touch-sensitive screen, allows the user 101 to manipulate a cursor on a display device to communicate further information and command selections to the processor 110.

The processor 110 outputs the results 122 of the execution of the program module 120 to the user device 130. Alternatively, the processor 110 can provide the output to a storage device 125, such as a database or memory, or via a network 135 to a remote device not shown.

For example, a program that performs the flowcharts of Figures 8 and 13 may be the program module 120. The system 100 may be operated as the controller 10.

The terms "comprising" or "comprising" should be interpreted as specifying the presence of the stated features, integers, steps, or components, but not excluding the presence of one or more other features, integers, steps, or components, or groups thereof. The terms "a" and "an" are indefinite articles and therefore do not exclude embodiments having a plurality thereof.

Other Embodiments
In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In short, the present invention is not limited to the above-described embodiment, and the components can be modified and embodied without departing from the spirit of the present invention at the implementation stage.

In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all of the components shown in the embodiments. Furthermore, components across different embodiments may be appropriately combined.

[appendix]
Here, the related technology will be described.

(Basic configuration)
First, the basic configuration of a control system of the related art will be described. Fig. 15 is a diagram illustrating a control system 400 of the related art. The control system 400 is a control system that controls traffic in a wireless network 15,
A terminal 11 and an access point 12 which transmit packets to each other via a wireless network 15;
a controller 13 that performs transmission control for the terminal 11 and the access point 12;
Equipped with
The controller 13 determines a bandwidth control value for each traffic flow based on the required bandwidth for each traffic flow notified at least from the terminal 11, and notifies the terminal 11 and the access point 12 of the bandwidth control value.

The control system 400 calculates the transmission bandwidth for each traffic flow using the required bandwidth for each traffic flow notified to the controller from the terminal 11. Therefore, the control system 400 can guarantee the bandwidth for each traffic flow.
There are two methods for bandwidth control for each traffic flow. These are explained in detail in Related Techniques 1 and 2.

(Related Technology 2)
In Related Art 2, a first bandwidth control technique will be described.
16 is a diagram illustrating a control system 401 of the related art. The control system 401 connects each terminal 11, an access point 12, and a controller 13.
Storing packets in buffers (FB1, FB2) for each traffic flow in each terminal 11 and access point 12, or in a buffer in an application;
notifying the controller 13 of the amount of accumulated packets in advance;
A scheduling unit SCH3 of the controller 13 determines a transmission time and a transmission amount for each traffic.
The controller 13 notifies each terminal 11 and access point 12 of the transmission time and transmission amount, and each terminal 11 and access point 12 transmits packets according to the notified transmission time and transmission amount.
It is assumed that the times of the terminals 11, the access points 12, and the controller 13 are synchronized using NTP, PTP, or the like.

Specifically, the control system 401 is a control system that controls traffic of the wireless network 15,
A terminal 11 and an access point 12 which transmit packets to each other via a wireless network 15;
a controller 13 that performs transmission control for the terminal 11 and the access point 12;
Equipped with
Each of the terminal 11 and the access point 12
Buffers (FB1, FB2) for storing transmission packets for each traffic flow;
an apparatus-side transmitting/receiving unit (CTR1, CTR2) that transmits to a controller 13 the amount of transmission packets accumulated for each traffic flow in a buffer (FB1, FB2) and receives from the controller 13 the transmission time and the transmission amount of the transmission packets for each traffic flow;
a main signal transmitting unit (MTR1, MTR2) for transmitting the transmission packets for each traffic flow in the buffer (FB1, FB2) to a wireless network 15 according to the transmission time and the transmission amount;
Equipped with
The controller 13 is
a control side transmitting/receiving unit CTR3 that receives the stored amount from each of the terminal 11 and the access point 12 and transmits the transmission time and the transmission amount to each of the terminal 11 and the access point 12;
a scheduling unit SCH3 that determines the transmission time and the transmission amount of the transmission packet for each traffic flow based on the accumulated amount;
Equipped with.

The control system 401 communicates control signals between the controller 13 and the access point 12/terminal 11 using a communication means separate from the communication means for the main signal (traffic packets). Specifically, the control signals are transmitted and received between the control signal transmitting/receiving unit CTR1 of the terminal 11 and the control signal transmitting/receiving unit CTR3 of the controller 13, and between the control signal transmitting/receiving unit CTR2 of the access point 12 and the control signal transmitting/receiving unit CTR3 of the controller 13.

Each terminal 11 and access point 12 periodically notifies the controller 13 of the amount of packets stored in the per-flow buffer units (FB1, FB2) as a control signal.
The terminal 11 accumulates packets from each application AP1 in a buffer FB1 for each application (for each flow). A packet amount notification unit NTF1 periodically checks the amount of packets accumulated in each buffer FB1 and notifies the controller 13 of the amount as a control signal via a control signal transmission/reception unit CTR1.
In addition, the access point 12 accumulates packets from the upper network device 50 in a buffer FB2 for each application (for each flow). A packet amount notification unit NTF2 periodically checks the amount of packets accumulated in each buffer FB2 and notifies the controller 13 of the amount as a control signal via a control signal transmission/reception unit CTR2.
The flow unit buffer unit FB1 may be owned by the application AP1.

The controller 13 records the notified packet accumulation amount, information on the terminal 11, the access point 12, and the flow unit buffers (FB1, FB2), and based on this determines the transmission time and transmission amount for each buffer and notifies each terminal 11 and access point 12 as a control signal.

The control signal transmission/reception unit CTR3 of the controller 13 receives control signals from each terminal 11 and access point 12, and organizes the packet accumulation amount contained in the control signal, information on the terminal 11, access point 12, and flow unit buffers (FB1, FB2) in a database DB.

17 is a diagram for explaining an example of information organized in the database DB. This database DB organizes the following three pieces of information:
The item number is a serial number for all the buffers (FB1, FB2) of the terminal 11 and the access point 12.
The node number is the number of the access point 12 or the terminal 11 .
The buffer number is the number of the buffer FB1 held by each terminal 11 or the number of the buffer FB2 held by the access point 12.
The amount of packets is the amount of packets stored in a buffer having the respective buffer number.
For example, item number K+2 indicates the amount of packets stored in the per-flow buffer unit FB1#2 of the terminal 11#1, and this amount is "B12."

The scheduling unit SCH3 of the controller 13 uses a scheduling method described below to determine the transmission time and transmission amount for each buffer from the contents of the database unit DB. The scheduling unit SCH3 then uses the determined transmission time and transmission amount as a control signal and transmits it from the control signal transmission/reception unit CTR3 to the terminal 11 and the access point 12.

Each terminal 11 and access point 12 extracts packets stored in the flow unit buffer units (FB1, FB2) at the notified transmission time and transmission amount and inputs them to the main signal buffer units (MB1, MB2). The main signal transmission/reception units (MTR1, MTR2) transmit the packets in the main signal buffer units (MB1, MB2) to the wireless network 15.

18 is a flowchart illustrating the above-described operation. The control method of the related art is a control method for controlling traffic on a wireless network 15, which includes the steps of:
The control method is a transmission control performed by a controller 13 on a terminal 11 and an access point 12 which transmit packets to each other via a wireless network 15,
Storing transmission packets for each traffic flow in the buffers (FB1, FB2) of the terminal 11 and the access point 12 (steps S111, S112, S121, S122);
Transmitting to the controller the amount of the transmission packets stored in each of the buffers for each traffic flow (steps S113 and S123);
determining, in the controller, a transmission time and a transmission amount of the transmission packet for each traffic flow based on the accumulated amount received from each of the terminal and the access point (steps S131 and S132);
Transmitting the transmission time and the transmission amount from the controller to each of the terminal and the access point (step S133); and transmitting the transmission packets for each traffic flow from the buffers of each of the terminal and the access point to the wireless network according to the transmission time and the transmission amount (steps S114, S124).
It is characterized by:

[effect]
19 and 20 are diagrams for explaining the effects of the control system 401. Fig. 19 is a sequence diagram of the control system 401, and Fig. 20 is a sequence diagram of a conventional communication system in which the controller 13 does not exist. In the diagrams, "RTS" means Request to Send, and "CTS" means Clear to Send. In addition, solid lines indicate communication of main signals, and dashed lines indicate communication of control signals.

As can be seen by comparing Figures 19 and 20, the communication operation from the main signal buffers (MB1, MB2) in Figure 19 is similar to the communication operation in Figure 20. The control system 401 of the present invention can be realized by disposing a controller 13 without modifying an existing communication system. Also, in the communication operation of Figure 20, there is no control of the transmission time, which causes problems such as packet collisions and bias in terminals and access points that can transmit, but the control system 401 of the present invention controls the transmission time for terminals and access points, eliminating the above problems.

[Scheduling method]
Here, the scheduling method performed by the scheduling unit SCH13 of the controller 13 will be described.
[1] Fair Scheduling This scheduling method performs calculations to divide the bandwidth or time by the total number of per-flow buffers (FB1, FB2) in which packets are stored in the terminal 11 and the access point 12.
The parameters are explained below.
The number of per-flow buffers in which packets are stored, including the terminal 11 and the access point 12 combined: n
Time for 1 cycle: T [sec]
Total transmission limit of main signal per cycle time: Z [Bytes/sec]
Time to transmit the first stored packet: t _start [sec]

フロー単位バッファ＃Ｊの送信時間Ｔ_Ｊ［ｓｅｃ］は、

フロー単位バッファ＃Ｊの送信時刻ｔ_Ｊ［ｓｅｃ］は、

と計算される。 in this case,
The transmission amount S _J [Bytes] of the per-flow buffer #J is

The transmission time T _J [sec] of the per-flow buffer #J is expressed as follows:

The transmission time t _J [sec] of per-flow buffer #J is expressed as follows:

It is calculated as follows.

The order in which flow unit buffers start transmitting may be, for example, starting from the lowest item number organized in the database unit DB of the controller 13.

[2] Scheduling Considering Bandwidth Weighting This scheduling method is determined based on the number of per-flow buffers (FB1, FB2) in which packets are stored in the terminal 11 and the access point 12 and the amount of packets stored therein.
The parameters are explained below.
Packet accumulation amount in per-flow buffer #J: B _J [Bytes]
Time for 1 cycle: T [sec]
Transmission limit per cycle: Z [Bytes/sec]
Time required to transmit all packets stored in all per-flow buffers: T _all [sec]
Time when the first packet is transmitted from all packets stored in the per-flow buffer: t _start [sec]

とすると、
フロー単位バッファ＃Ｊの送信量Ｓ_Ｊ［Ｂｙｔｅｓ］は、
Ｔ_ａｌｌ≦Ｔの場合、

Ｔ_ａｌｌ＞Ｔの場合、

フロー単位バッファ＃Ｊの送信時間Ｔ_Ｊ［ｓｅｃ］は、
Ｔ_ａｌｌ≦Ｔの場合、

Ｔ_ａｌｌ＞Ｔの場合、

フロー単位バッファ＃Ｊの送信時刻ｔ_Ｊ［ｓｅｃ］は、
Ｔ_ａｌｌ≦Ｔの場合、

Ｔ_ａｌｌ＞Ｔの場合、

と計算される。 in this case,

Then,
The transmission amount S _J [Bytes] of the per-flow buffer #J is
If T _all ≦T,

If T _all >T,

The transmission time T _J [sec] of the per-flow buffer #J is expressed as follows:
If T _all ≦T,

If T _all >T,

The transmission time t _J [sec] of per-flow buffer #J is expressed as follows:
If T _all ≦T,

If T _all >T,

It is calculated as follows.

If T _all >T, packets that cannot be transmitted are carried over to the next transmission timing.

(Related Technology 3)
In Related Art 3, a second bandwidth control technique will be described.
21 is a diagram illustrating a control system 402 of the related art. The control system 402 connects each terminal 11, an access point 12, and a controller 13.
A bandwidth control unit (FBC1, FBC2) is provided in each terminal 11 and in each traffic flow unit in the access point 12, or a bandwidth control unit is provided in the application.
The terminal 11 notifies the controller 13 of the required bandwidth in advance;
A bandwidth control setting calculation unit BCSC of the controller 13 determines a bandwidth control value for each traffic flow for each access point 12 and each terminal 11;
The bandwidth control value is notified to each terminal 11 and access point 12, and each terminal 11 and access point 12 transmits packets of each traffic within the range of the notified bandwidth control value.
It is assumed that the times of the terminals 11, the access points 12, and the controller 13 are synchronized using NTP, PTP, or the like.
Bandwidth control is performed using policing, shaping, etc.
The difference between the first bandwidth control method and the second bandwidth control method is that the bandwidth control value is not changed unless the required bandwidth is changed due to the addition of an application or the like, whereas the first bandwidth control method controls transmission for each packet.

Specifically, the control system 402 is a control system that controls traffic on the wireless network 15 and has the following features.
The terminal 11 is
a terminal-side transmitting/receiving unit CTR1 that transmits a bandwidth required by the application AP1 to the controller 13 as the required bandwidth when the application AP1 is connected to the controller 13 and when the application AP1 is added, and receives a bandwidth control value from the controller 13;
and a terminal-side bandwidth control unit (BCS1, FBC1) for setting the bandwidth control value to each application AP1.
The access point 12 is
an access point side transceiver unit CTR2 that receives the bandwidth control value from a controller 13;
and an access point-side bandwidth control unit (BCS2, FBC2) that sets the bandwidth control value to each of the applications.
The controller 13 is
a control side transceiver unit CTR3 that receives the required bandwidth from the terminal 11 and transmits the bandwidth control value to each of the terminal 11 and the access point 12;
a calculation unit BCSC for determining the bandwidth control value based on the sum of the required bandwidth;
Equipped with.

In this related technique, it is assumed as a precondition that the terminals 11 and the access points 12 are all under the control of the controller 13 .
The control system 402 communicates control signals between the controller 13 and the access points 12/terminals 11 over a communication means separate from that of the main signals (traffic packets).
Specifically, control signals are transmitted and received between a control signal transmitter/receiver unit CTR1 of the terminal 11 and a control signal transmitter/receiver unit CTR3 of the controller 13, and between a control signal transmitter/receiver unit CTR2 of the access point 12 and a control signal transmitter/receiver unit CTR3 of the controller 13.

When the controller 13 and each terminal 11 are connected, or when a terminal 11 and application AP1 are added, the application AP1 of each terminal 11 notifies the controller 13 of the required bandwidth needed for upstream and downstream main signal communication.

The controller 13 records the notified necessary bandwidth in the database unit DB, adds up the necessary bandwidths of each application AP1, and checks whether they fall within the communication bandwidth (main signal bandwidth) of the wireless network 15.
If the total required bandwidth falls within the main signal bandwidth, the total required bandwidth is notified to the bandwidth control setting unit BCS1 of each terminal 11 and the bandwidth control setting unit BCS2 of the access point 12 as a bandwidth control value for each flow.
On the other hand, if the total required bandwidth does not fall within the main signal bandwidth, the required bandwidth is subtracted so that the total required bandwidth falls within the main signal bandwidth, as described below, and this is notified to the bandwidth control setting unit BCS1 of each terminal 11 and the bandwidth control setting unit BCS2 of the access point 12 as a bandwidth control value per flow.

The bandwidth control setting units (BCS1, BCS2) set the bandwidth control values notified by the controller 13 to each of the flow-based bandwidth control units (FBC1, FBC2) under them. Each flow-based bandwidth control unit FBC1 inputs packets from the application AP1 to the main signal buffer unit MB1 according to the set bandwidth control value. Meanwhile, each flow-based bandwidth control unit FBC2 inputs packets from the main signal transmitting/receiving unit (upper) MTRU to the main signal buffer unit MB2 according to the set bandwidth control value. The main signal transmitting/receiving units (MTR1, MTR2) transmit packets from the main signal buffer units (MB1, MB2) to the wireless network 15.

22 is a diagram illustrating an example of information organized in the database DB. This database DB organizes the following three pieces of information:
The item number is a serial number for all traffic flows between the terminal 11 and the access point 12 .
The node number is the number of the access point 12 or the terminal 11 .
The traffic flow number is the number of the application AP1 held by each terminal 11 or the number of a traffic flow passing through the access point 12.
The required bandwidth is the bandwidth required by each traffic flow (application).
For example, item number K+2 indicates the required bandwidth for the traffic flow of application AP1#2 of terminal 11#1, and the amount is "B _(K+1)2 ."

23 is a flowchart illustrating the above-described operation. The control method of the related art is a control method for controlling traffic in the wireless network 15.
The control method is transmission control performed by the controller 13 on the terminal 11 and the access point 12 which transmit packets to each other via the wireless network 15 .
When each terminal 11 is connected to the controller 13 or when an application AP1 is added, the terminal 11 notifies the controller 13 of the node number, application number (traffic flow number) and required bandwidth for each application (step S211).
The controller 13 records the node number, application number (traffic flow number), and required bandwidth for upstream and downstream communication of each flow received from each terminal 11 in the database unit DB (step S231).
The bandwidth control setting calculation unit BCSC of the controller 13 calculates the sum of the required bandwidth in the main signal section (network 15) based on the information in the database unit DB (step S232).
The bandwidth control setting calculation unit BCSC of the controller 13 compares the calculated sum amount with the communication bandwidth of the network 15 (step S233).
If the sum amount<communication bandwidth ("Yes" in step S233), the bandwidth control setting calculation unit BCSC determines the required bandwidth of each flow as a bandwidth control value (step S234).
If the sum amount is greater than or equal to the communication bandwidth (step S233: No), the bandwidth control setting calculation unit BCSC subtracts the required bandwidth of each flow so that the sum amount is within the communication bandwidth, and determines the subtracted required bandwidth as the bandwidth control value (step S235).
The control signal transmitting/receiving unit CTR3 notifies the access point 12 and each terminal 11 of the bandwidth control value determined by the bandwidth control setting calculation unit BCSC (step S236).
The bandwidth control setting unit BCS2 of the access point 12 sets the bandwidth control value of each flow notified by the controller 13 in the per-flow bandwidth control unit FBC2 (step S227).
The bandwidth control setting unit BCS1 of the terminal 11 sets the bandwidth control value of each flow notified by the controller 13 in the per-flow bandwidth control unit FBC1 (step S217).
The terminal 11 transfers packets at the set bandwidth control value for a certain period of time (step S218), and checks whether or not a new application AP1 has been added (step S219).
If a new application AP1 has been added ("Yes" in step S219), the control method repeats the operation from step S211. On the other hand, if a new application AP1 has not been added ("No" in step S219), the terminal 11 waits again for a certain period of time in step S218.

[effect]
Fig. 24 and Fig. 19 are diagrams for explaining the effects of the control system 402. Fig. 24 is a sequence diagram of the control system 402, and Fig. 19 is a sequence diagram of a conventional communication system in which the controller 13 does not exist. In the diagrams, "RTS" means Request to Send, and "CTS" means Clear to Send. In addition, solid lines indicate communication of main signals, and dashed lines indicate communication of control signals.

As can be seen by comparing Figure 24 with Figure 19, the communication operation from the main signal buffers (MB1, MB2) in Figure 24 is similar to the communication operation in Figure 19. The control system 402 of the present invention can be realized by disposing a controller 13 without modifying the existing communication system. Also, in the communication operation in Figure 19, transmission control is performed on a terminal basis, so it is difficult to allocate bandwidth to detailed traffic flow units such as services and applications, but the control system 402 of the present invention follows the bandwidth control value for each traffic flow notified by the controller, so it is possible to guarantee the bandwidth allocated to each traffic flow.

[Bandwidth control value calculation formula]
Here, a method for calculating the bandwidth control value performed by the bandwidth control setting calculation unit BCSC of the controller 13 will be described.
The parameters are as follows:
Total number of flows between terminal 11 and access point 12: n
Main signal band: Z [Bytes/sec]
Total required bandwidth of all flows (sum amount): R _all [Bytes/sec]
Required bandwidth of flow #J: R _j [Bytes/sec]
Bandwidth control setting value of flow #J: B _J [Bytes/sec]

であり、Ｒ_ａｌｌ≦Ｚならば、各フローの帯域制御設定値は、それぞれが要求した必要帯域であり、フロー＃Ｊであれば、
［数９］
ＢＪ＝Ｒｊ
となる。
一方、Ｒ_ａｌｌ＞Ｚならば、各フローの帯域制御設定値は、それぞれが要求した必要帯域より小さくする必要がある。例えば、フロー＃Ｊであれば、

となる。 in this case,

If R _all ≦Z, the bandwidth control setting value of each flow is the required bandwidth requested by each flow. For flow #J,
[Equation 9]
BJ=Rj
It becomes.
On the other hand, if R _all >Z, the bandwidth control setting value of each flow needs to be smaller than the required bandwidth requested by each flow. For example, for flow #J,

It becomes.

10: Controller 11: Database 12: Scheduling unit 13: Control signal transmission/reception unit 20: Terminal 21: Control signal transmission/reception unit 22: Packet amount notification unit 23: Scheduler unit 24: Application 25: Flow unit buffer unit 26: Main signal buffer unit 27: Main signal transmission/reception unit 30: Network upper level device 30a: Access point 31: Control signal transmission/reception unit 32: Packet transmission request unit 33: Main signal transmission/reception unit (lower level)
34: Main signal transmitter/receiver unit (upper)
40: Network lower level device 40a: ONU
41: Control signal transmission/reception unit 42: Packet transmission request unit 43: Main signal transmission/reception unit (lower)
44: Main signal transceiver unit (upper)
50, 50#1, 50#2: network 60: network host device 60a: OLT
61: Control signal transmission/reception unit 62: Scheduler unit 63: Packet amount notification unit 64: Main signal transmission/reception unit (upper)
65: Per-flow buffer unit 66: Main signal buffer unit 67: Main signal transmission/reception unit 70: Upper network device 100: System 101: User 105: Computer 110: Processor 115: Memory 120: Program module 122: Result 125: Storage device 130: User device 135: Network 140: Storage device 150: Data source [In appendix]
11: Terminal 12: Access point 13: Controller 15: Wireless network 50: Upper network devices 400, 401, 402: Control system

Claims (7)

A communication system having a plurality of time division multiplexed networks and a controller,
The network is connected in multiple stages,
The controller:
a database for storing communication times required for communication from a transmission request to packet transmission for each of the networks;
a scheduler which, when transmitting a packet on a flow unit basis from any communication device included in any one of the networks, notifies the communication device of a transmission time for transmitting the packet, and notifies a connection device included in another of the networks connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the transmission time and the communication time of the other network;
A communication system comprising: The communication system according to claim 1, characterized in that the plurality of networks are a PON (Passive Optical Network) and a wireless LAN (Local Area Network), and when the network is the PON, the connection device of the other network is an access point, and when the network is the wireless LAN, the connection device of the other network is an ONU (Optical Network Unit). A communication method for controlling a time division multiplexing network having multiple connections, comprising the steps of:
storing a communication time required for communication from a transmission request to a packet transmission of each of the networks; and when transmitting a packet on a flow basis from an arbitrary communication device included in any of the networks, notifying the communication device of a transmission time for transmitting the packet, and notifying a connection device included in another of the networks connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the sending time and the communication time of the other network;
A communication method comprising: The communication method according to claim 3, characterized in that the networks connected in multiple stages are a PON (Passive Optical Network) and a wireless LAN (Local Area Network), and when the network is the PON, the connection device of the other network is an access point, and when the network is the wireless LAN, the connection device of the other network is an ONU (Optical Network Unit). A controller for controlling a time division multiplexing network connected in multiple stages, comprising:
a database for storing communication times required for communication from a transmission request to packet transmission for each of the networks;
a scheduler which, when transmitting a packet on a flow unit basis from any communication device included in any one of the networks, notifies the communication device of a transmission time for transmitting the packet, and notifies a connection device included in another of the networks connected to the network of an issuing time for the connection device to issue a transmission request for transmitting the packet to the other network, taking into consideration the transmission time and the communication time of the other network;
A controller comprising: The controller according to claim 5, characterized in that the plurality of networks are a PON (Passive Optical Network) and a wireless LAN (Local Area Network), and when the network is the PON, the connection device of the other network is an access point, and when the network is the wireless LAN, the connection device of the other network is an ONU (Optical Network Unit). A program for causing a computer to function as the controller according to claim 5 or 6.

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