CONTROL SYSTEM, CONTROL METHOD, CONTROLLER, AND PROGRAM

Abstract

The purpose of this disclosure is to enable bandwidth allocation in traffic flow units even in real wireless networks where terminals are repeatedly connected and disconnected due to the movement of people or the like.　The present disclosure is a control system for controlling traffic in a wireless network, the system including a controller that controls transmission to a terminal and an access point. The controller: establishes a connection with the terminal using a connection sequence based on a protocol that can be used in the wireless network before the access point establishes a connection with the terminal; acquires information from the terminal on the node number and flow unit buffer of said terminal; and after the access point establishes a connection with the terminal, performs transmission control for each traffic flow stored in the flow unit buffer of the terminal using the acquired node number and flow unit buffer information of the terminal.

Description

[Technical field]

[0001] The present disclosure relates to a control system, a control method, a controller, and a program for allocating a communication band within an access network. [Background technology]

[0002] In recent years, studies have been conducted on accommodating 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."

[0003] The end-to-end network can be divided into wireless and wired sections. In the wireless section, there is a priority control function called Enhanced Distributed Channel Access (EDCA) of IEEE802.11 as an existing technology (Non-Patent Documents 1 and 2).

[0004] EDCA is a control for terminals (destinations), and it is difficult to control for traffic flows, which allows quality control for services and applications. Therefore, a technology has been proposed that realizes quality control for services and applications (see, for example, Non-Patent Document 3). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] IEEE 802.11e-2005 - IEEE Standard for Information technology--Local and metropolitan area networks--Specific requirements--Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications - Amendment 8: Medium Access Control (MAC) Quality of Service Enhancements [Non-Patent Document 2] IEEE802.11e: Wireless LAN standard that realizes QoS” Journal of the Institute of Image Information and Television Engineers, Vol. 57, No. 11 [Non-Patent Document 3] Yuki Sakagami, Kazuki Aiura, Tatsuya Fukui, et al.: "Proposal of quality control technology by centralized control independent of wireless network", Institute of Electronics, Information and Communication Engineers General Conference, March 9, 2021, B-6-5 Summary of the Invention [Problem to be solved by the invention]

[0006] In Non-Patent Document 3, it is necessary to record in advance the connected terminals and access points in the database section. However, in the case of real terminals in a wireless network, connection / disconnection is repeated due to people moving around, etc., so it is difficult to record all terminals and access points in the controller in advance.

[0007] The present disclosure aims to enable bandwidth allocation on a traffic flow basis even in real-world wireless networks where terminals repeatedly connect and disconnect due to factors such as people moving around. [Means for solving the problem]

[0008] The control system according to the present disclosure comprises: A control system for controlling traffic in a wireless network, comprising: a terminal and an access point for transmitting packets to each other via the wireless network; A controller that performs transmission control on the terminal and the access point; Equipped with The terminal holds in advance information on its own node number and per-flow buffer; The controller: Before the access point establishes a connection with the terminal, the access point establishes a connection with the terminal using a connection sequence according to a protocol available in the wireless network; acquiring, from the terminal, the node number of the terminal and information of a per-flow buffer through the wireless network; After the access point establishes a connection with the terminal, it performs transmission control for each traffic flow stored in the per-flow buffer of the terminal using the node number of the terminal and per-flow buffer information obtained through the wireless network.

[0009] The control method according to the present disclosure includes: A method for controlling traffic in a wireless network, comprising: The control method includes a transmission control performed by a controller on a terminal and an access point that transmit packets to each other via the wireless network, Before the access point establishes a connection with the terminal, The controller: Establishing a connection with the terminal using a connection sequence according to a protocol available in the wireless network; acquiring, from the terminal, through the wireless network, information on the node number of the terminal itself and information on a per-flow buffer that is previously stored in the terminal; After the access point establishes a connection with the terminal, The controller performs transmission control for each traffic flow stored in the per-flow buffer of the terminal, using the node number of the terminal and the per-flow buffer information acquired through the wireless network.

[0010] The controller according to the present disclosure comprises: A controller for controlling traffic in a wireless network, comprising: The controller is a device that performs transmission control on terminals and access points that transmit packets to each other via the wireless network, Before the access point establishes a connection with the terminal, Establishing a connection with the terminal using a connection sequence according to a protocol available in the wireless network; acquiring, from the terminal, through the wireless network, information on the node number of the terminal itself and information on a per-flow buffer that is previously stored in the terminal; After the access point establishes a connection with the terminal, The controller performs transmission control for each traffic flow stored in the per-flow buffer of the terminal, using the node number of the terminal and the per-flow buffer information acquired through the wireless network.

[0011] The program of the present disclosure is a program for causing a computer to realize each functional unit of an apparatus of the present disclosure, and is a program for causing a computer to execute each step of a method performed by an apparatus of the present disclosure. Effect of the Invention

[0012] According to the present disclosure, even in a real wireless network where terminals repeatedly connect / disconnect due to people moving around, etc., it is possible to allocate bandwidth on a traffic flow basis. [Brief description of the drawings]

[0013] [Figure 1] 1 illustrates an example of a system configuration according to the present disclosure. [Diagram 2] 2 shows an example of the configuration of an access point. [Diagram 3] FIG. 2 is a diagram illustrating a database included in an access point. [Figure 4] 1 shows an example of the configuration of a controller. [Diagram 5] FIG. 2 is a diagram illustrating a database included in the controller. [Figure 6] An example of the terminal configuration is shown. [Figure 7] FIG. 2 is a diagram illustrating a database provided in a terminal. [Figure 8] 13 shows a flowchart when a terminal is newly connected. [Figure 9] 13 shows a flowchart when a terminal is newly connected. [Figure 10] FIG. 2 is a flowchart illustrating the operation of the system of the present disclosure. [Figure 11] FIG. 2 is a sequence diagram of a control system according to the present disclosure. [Figure 12] FIG. 1 is a sequence diagram of a conventional communication system in which a controller is not present. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings are assumed to indicate the same components.

[0015] (Example 1) 1 shows an example of a system configuration of the present disclosure. In the communication network of the present disclosure, each terminal 11 is connected to an access point 12 through a wireless network 15. The control system of the present disclosure includes a controller 13 that controls this communication network. The controller 13 is connected to the access point 12 through a dedicated control network. The controller 13 is connected to each terminal 11 through a connection sequence based on a protocol available in the wireless network 15.

[0016] 2 shows an example of the configuration of the access point 12. The access point 12 includes a database unit 21, a control signal transmission / reception unit 22, and a scheduler unit 23. The access point 12 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.

[0017] 3 shows an example of information stored in the database unit 21. The database unit 21 organizes information on the per-flow buffers FB2#1 to FB2#K of its own device. In this manner, in this embodiment, the access point 12 records its own buffer numbers in its own database unit 21.

[0018] 4 shows an example of the configuration of the controller 13. The controller 13 includes a database unit 31, a control signal transmission / reception unit 32, and a scheduling unit 33. The controller 13 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.

[0019] The database unit 31 organizes information about the per-flow buffers in the access point 12 and the terminal 11. Fig. 5 is a diagram for explaining an example of information organized in the database unit 31. 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 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 packet amount is the amount of packets stored in the buffer having the respective buffer number. For example, item number K+2 is the amount of packets stored in the per-flow buffer unit FB1#2 of terminal 11#1, and the amount is "B12". When the terminal 11#N+1 is newly connected, the node number and buffer number of the terminal 11#N+1 are not stored in the database unit 31.

[0020] Information about the access point 12 is stored in the database unit 31 when the access point 12 is installed. At this time, the database unit 31 also stores protocols that the access point 12 can support.

[0021] Fig. 6 shows an example of the configuration of the terminal 11. The terminal 11 includes a database unit 41, a control signal transmission / reception unit 42, and a scheduler unit 43. Fig. 7 shows an example of information stored in the database unit 41. The database unit 41 organizes information on its own node number and per-flow buffers FB1#1 to FB1#L. Thus, in this embodiment, each terminal 11 records its own node number and buffer number in its own database unit 41.

[0022] FIG. 8 shows a flow chart when the terminal 11#N+1 makes a new connection. Before connecting to the access point 12, the newly connected terminal 11#N+1 establishes a connection with the controller 13 in accordance with a connection sequence based on a protocol available in the wireless network 15 (S101). After newly connecting terminal 11#N+1 is connected to controller 13, it notifies controller 13 of the node number and buffer number recorded in database unit 11 as a newly connecting terminal (S102). The controller 13 records the node number #N+1 of the terminal 11#N+1 and the buffer number held by the terminal 11#N+1 in the database unit 31 (S103). This allows the node numbers and buffer numbers of all the terminals 11#1 to 11#N+1 to be recorded in advance in the controller 13.

[0023] Here, in step S101, the protocol used by the controller 13 when establishing a connection with the terminal 11#N+1 complies with the protocol of the wireless network 15 available to the terminal 11#N+1. For example, the controller 13 receives a wireless signal by which the terminal 11#N+1 searches for the access point 12, and establishes a connection with the terminal 11#N+1 through a connection sequence according to a protocol compatible with the received wireless signal.

[0024] The protocol for communication between the terminal 11#N+1 and the controller 13 may be different from that for data communication between the terminal 11#N+1 and the access point 12. For example, the protocol for communication between the terminal 11#N+1 and the controller 13 may be a low-speed protocol that allows communication even when the radio waves are weak, and the protocol for communication between the terminal 11#N+1 and the access point 12 may be a high-speed protocol.

[0025] After step S103, terminal 11 notifies controller 13 of the bandwidth required by the application. Controller 13 records the notified required bandwidth in database unit 31, and determines a bandwidth control value for each traffic flow for terminal 11 and access point 12 based on the recorded database information, and notifies each terminal 11 and access point 12. Each terminal 11 and access point 12 transmits each traffic packet within the notified bandwidth control value range. In this way, the present disclosure enables bandwidth allocation for each fine traffic flow, such as a service or application, in a real wireless network.

[0026] (Example 2) The newly connected terminal 11#N+1 does not know whether the node number and buffer number that it notified have been reliably recorded in the controller 13. In normal communication, there is a possibility that the notification may be corrupted or lost due to packet loss, etc. Therefore, in this embodiment, the node number and buffer number of the newly connected terminal 11#N+1 are reliably notified to the controller 13.

[0027] 9 shows a flowchart when the terminal 11#N+1 newly connects. In this embodiment, the following steps are executed after step S103 shown in FIG. When recording in the database unit 31, the controller 13 notifies the newly connected terminal 11#N+1 of a connection confirmation indicating that the information has been recorded in the database unit (S201). The newly connected terminal 11#N+1 transmits the node number and buffer number notified at the time of connection multiple times until a connection confirmation notification arrives from the controller 13 (S202). When the connection confirmation notification arrives, the terminal 11#N+1 notifies the controller 13 of the buffer amount (S203).

[0028] There are cases where the controller 13 receives the node number and buffer number from the terminal 11#N+1 even after the controller 13 has recorded the node number and buffer number of the terminal 11#N+1 in the database unit 31. In such a case, the controller 13 resends the connection confirmation notification.

[0029] (Example 3) Each of the terminal 11 and the access point 12 Buffers (FB1, FB2) that store transmission packets for each traffic flow; a control signal transmitting / receiving unit (42, 22) that transmits to a controller 13 an accumulated amount of the transmission packets for each traffic flow accumulated in a buffer (FB1, FB2) and receives from the controller 13 a transmission time and a 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 control signal transmitting / receiving unit 32 receives the accumulated 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. The scheduling unit 33 determines the transmission time and the transmission amount of the transmission packet for each traffic flow based on the accumulated amount.

[0030] 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 44 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 42. In addition, the access point 12 accumulates packets from the upper network device 50 in the buffer FB2 for each application (for each flow). The packet amount notifying unit 24 periodically checks the amount of packets accumulated in each buffer FB2 and notifies the controller 13 of the amount as a control signal via the control signal transmitting / receiving unit 22. The per-flow buffer unit FB1 may be owned by the application AP1.

[0031] The controller 13 records the notified packet accumulation amount, information on the terminal 11, the access point 12, and the per-flow buffers (FB1, FB2), and based on that determines the transmission time and transmission amount for each buffer and notifies each terminal 11 and access point 12 as a control signal.

[0032] The control signal transmitting / receiving unit 32 of the controller 13 receives control signals from each terminal 11 and access point 12, and organizes in a database DB31 information included in the control signals regarding the amount of accumulated packets, the terminal 11, the access point 12, and the per-flow buffers (FB1, FB2).

[0033] The scheduling unit 33 of the controller 13 uses a scheduling method described later to determine the transmission time and transmission amount for each buffer from the contents of the database unit DB31. The scheduling unit 33 then uses the determined transmission time and transmission amount as a control signal, and transmits it from the control signal transmitting / receiving unit 32 to the terminal 11 and the access point 12.

[0034] Each terminal 11 and access point 12 extracts packets stored in the per-flow 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 transceiver units (MTR1, MTR2) transmit the packets in the main signal buffer units (MB1, MB2) to the wireless network 15.

[0035] 10 is a flowchart illustrating the above-described operation. The control method of this embodiment is a control method for controlling traffic in the wireless network 15, 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 the terminal and the access point, respectively (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 the terminal and the access point to the wireless network according to the transmission time and the transmission amount (steps S114 and S124). It is characterized by:

[0036] [effect] Figures 11 and 12 are diagrams for explaining the effects of the control system of the present disclosure. Figure 11 is a sequence diagram of the control system of the present disclosure, and Figure 12 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.

[0037] 11 and 12, the communication operation from the main signal buffers (MB1, MB2) in Fig. 11 is similar to the communication operation in Fig. 12. The control system of the present disclosure can be realized by disposing a controller 13 without modifying an existing communication system. In addition, in the communication operation of Fig. 12, since there is no control of the transmission time, problems occur such as packet collisions and bias in terminals and access points that can transmit, but the control system of the present disclosure controls the transmission time for terminals and access points, and therefore the above problems are eliminated.

[0038] [Scheduling method] Here, the scheduling method performed by the scheduling unit 33 of the controller 13 will be described. [1] Fair scheduling This scheduling method performs calculations in which the bandwidth or time is divided 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: Z [Bytes / sec] Time to send the first stored packet: t start [sec]

[0039] in this case, Transmission volume S of flow unit buffer #J J [Bytes] is

number

number

number

[0040] The order of the per-flow buffers from which transmission is started may be, for example, from the smallest number of item numbers organized in the database unit DB31 of the controller 13.

[0041] [2] Scheduling with consideration of bandwidth weighting This scheduling method is determined based on the number of per-flow buffers in which packets are stored, and the amount of packets stored, among the per-flow buffers (FB1, FB2) of terminal 11 and access point 12. 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] The time when the first packet is transmitted from all the packets stored in the per-flow buffer: t start [sec]

[0042] in this case,

number

number

number

number

number

number

number

[0043] In addition, T all If >T, packets that cannot be sent are carried over to the next transmission timing. [Industrial Applicability]

[0044] The present disclosure can be applied to the information and communications industry. [Explanation of symbols]

[0045] 11: Terminal 12: Access point 13: Controller 15: Wireless network 21, 31, 41: Database section 22, 32, 42: control signal transmission / reception unit 23, 43: Scheduler section 24, 44: Packet amount notification section 33: Scheduling department

Claims

1. A control system for controlling traffic in a wireless network, comprising: a terminal and an access point for transmitting packets to each other via the wireless network; A controller that performs transmission control on the terminal and the access point; Equipped with The terminal holds in advance information on its own node number and per-flow buffer; The controller: Before the access point establishes a connection with the terminal, the access point establishes a connection with the terminal using a connection sequence according to a protocol available in the wireless network; acquiring, from the terminal, the node number of the terminal and information of a per-flow buffer through the wireless network; receiving notification of a bandwidth required for an application from the terminal, determining a bandwidth control value for a traffic flow for each of the terminals and the access point based on the notified required bandwidth, and notifying the terminal and the access point so that the terminal and the access point transmit packets of each traffic within a range of the bandwidth control value; After the access point establishes a connection with the terminal, the access point performs transmission control for each traffic flow stored in the per-flow buffer of the terminal, using the node number of the terminal and the per-flow buffer information acquired through the wireless network. Control system.

2. When the controller acquires the node number and the per-flow buffer information from the terminal, the controller notifies the terminal of a connection confirmation indicating that the information has been acquired. The control system of claim 1 .

3. A method for controlling traffic in a wireless network, comprising: The control method includes a transmission control performed by a controller on a terminal and an access point that transmit packets to each other via the wireless network, Before the access point establishes a connection with the terminal, The controller: Establishing a connection with the terminal using a connection sequence according to a protocol available in the wireless network; acquiring, from the terminal, through the wireless network, information on the node number of the terminal itself and information on a per-flow buffer that is previously stored in the terminal; receiving notification of a bandwidth required for an application from the terminal, determining a bandwidth control value for a traffic flow for each of the terminals and the access point based on the notified required bandwidth, and notifying the terminal and the access point so that the terminal and the access point transmit packets of each traffic within a range of the bandwidth control value; After the access point establishes a connection with the terminal, the controller performs transmission control for each traffic flow stored in the per-flow buffer of the terminal, using the node number of the terminal and the per-flow buffer information acquired through the wireless network; Control methods.

4. A controller for controlling traffic in a wireless network, comprising: The controller is a device that performs transmission control on terminals and access points that transmit packets to each other via the wireless network, Before the access point establishes a connection with the terminal, Establishing a connection with the terminal using a connection sequence according to a protocol available in the wireless network; acquiring, from the terminal, through the wireless network, information on the node number of the terminal itself and information on a per-flow buffer that is previously stored in the terminal; receiving notification of a bandwidth required for an application from the terminal, determining a bandwidth control value for a traffic flow for each of the terminals and the access point based on the notified required bandwidth, and notifying the terminal and the access point so that the terminal and the access point transmit packets of each traffic within a range of the bandwidth control value; After the access point establishes a connection with the terminal, the controller performs transmission control for each traffic flow stored in the per-flow buffer of the terminal, using the node number of the terminal and the per-flow buffer information acquired through the wireless network; controller.

5. A program for causing a computer to function as the controller according to claim 4.

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