Control System, Control Method, Controller, and Program

Abstract

The purpose of this disclosure is to make it possible to reduce the inaccuracy in accumulated packet volume due to the nonarrival of accumulated packet volume notification when control signal communication for quality control is implemented by radio communication.　A control system according to this disclosure includes a terminal and an access point that transmit packets to each other via a radio network and a controller that performs transmission control for the terminal and the access point via the radio network. The controller includes: a database unit that records the latest accumulated volume received at a first cycle and a past accumulated volume used to determine a past transmission time and a past transmission volume; and a scheduling unit that estimates, at each second cycle, a current accumulated volume on the basis of the latest accumulated volume and the past accumulated volume recorded in the database unit and determines the transmission time and the transmission volume of transmission packets for each traffic flow on the basis of the estimated current accumulated volume.

Description

Technical Field

[0001] The present disclosure relates to quality control technology in a network (NW).

Background Art

[0002] In recent years, there has been a growing consideration of accommodating multiple services and applications with various network requirements on the same network infrastructure. To this end, in the End - End section from "terminal to terminal" or "terminal to application server", the quality required by each service and application accommodated in the same NW (Network) must be guaranteed.

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

[0004] EDCA is a control at the terminal (destination) unit, and it is difficult to perform control at the traffic flow unit that enables quality control at the service and application units. However, by applying the "technology of Non - Patent Document 3", quality control at the service and application units can be realized.

Prior Art Documents

Non - Patent Documents

[0005]

Non - Patent Document 1

[0006] However, in the quality control at the service and application units shown in Non-Patent Document 3, when the control signal communication for quality control is made wireless, there is a problem that due to the lack of packet accumulation amount notification from terminals and access points to the controller sent by the control signal, data transmission scheduling based on inaccurate packet accumulation amounts is performed.

[0007] In order to solve the above problems, an object of the present disclosure is to provide a control system, a control method, a controller, and a program that can reduce the inaccuracy of the packet accumulation amount due to the lack of packet accumulation amount notification when the control signal communication for quality control is made wireless. [Means for Solving the Problems]

[0008] To achieve the above object, the present disclosure controls the transmission time and transmission amount of packets for each traffic flow based on the latest and past accumulation amounts of transmission packets accumulated in the buffers of the terminal and the access point, respectively.

[0009] Specifically, the control system according to the present disclosure is a control system for controlling the traffic of a wireless network, including a terminal and an access point that mutually transmit packets via the wireless network, and a controller that performs transmission control on the terminal and the access point via the wireless network, and is provided with each of the terminal and the access point includes a buffer for accumulating transmission packets for each traffic flow, a device-side transmission / reception unit that transmits the accumulation amount of the transmission packets for each traffic flow accumulated in the buffer to the controller in a first period and receives the transmission time and transmission amount of the transmission packets for each traffic flow from the controller in a second period, and a main signal transmission unit that transmits the transmission packets for each traffic flow in the buffer to the wireless network connecting the terminal and the access point according to the transmission time and the transmission amount, and is provided with the controller includes a control-side transmission / reception unit that receives the accumulation amount from each of the terminal and the access point in the first period and transmits the transmission time and the transmission amount to each of the terminal and the access point in the second period, and a database unit that records the latest accumulation amount received by the control-side transmission / reception unit and the past accumulation amount used to determine the past transmission time and transmission amount, For each of the second periods, based on the latest accumulation amount and the past accumulation amount recorded in the database unit, estimate the current accumulation amount, and based on the estimated current accumulation amount, determine the transmission time and the transmission amount of the transmission packet for each traffic flow, a scheduling unit; comprising.

[0010] Specifically, the control method according to the present disclosure is a control method for controlling traffic of a wireless network, wherein the control method is transmission control performed by a controller via a wireless network with respect to a terminal and an access point that mutually transmit packets via the wireless network, accumulating transmission packets for each traffic flow in respective buffers of the terminal and the access point; transmitting, in a first period, the accumulation amount of the transmission packets for each traffic flow accumulated in each of the buffers to the controller; at the controller, recording the latest accumulation amount and the past accumulation amount received from each of the terminal and the access point in the first period; for each of the second periods, at the controller, estimating the current accumulation amount based on the recorded latest accumulation amount and the past accumulation amount, and determining the transmission time and the transmission amount of the transmission packet for each traffic flow based on the estimated current accumulation amount; transmitting the transmission time and the transmission amount from the controller to each of the terminal and the access point, and transmitting, according to the transmission time and the transmission amount, the transmission packets for each traffic flow from the respective buffers of the terminal and the access point to the wireless network connecting the terminal and the access point characterized in that it is a control method, wherein the past accumulation amount is the accumulation amount used to determine the past transmission time and the transmission amount characterized by.

[0011] Specifically, the controller according to the present disclosure is a controller that controls the traffic of a wireless network, and the controller is a device that performs transmission control via a wireless network on terminals and access points that mutually transmit packets via the wireless network, receives, in a first period, the amount of transmitted packets accumulated for each traffic flow in respective buffers of the terminal and the access point, and transmits, in a second period, the transmission time and the transmission amount of the transmitted packets for each traffic flow to each of the terminal and the access point; a control-side transceiver, a database unit that records the latest amount of accumulation received by the control-side transceiver and the past amount of accumulation used to determine the past transmission time and the transmission amount; a scheduling unit that estimates the current amount of accumulation based on the latest amount of accumulation and the past amount of accumulation recorded in the database unit every second period, and determines the transmission time and the transmission amount of the transmitted packets for each traffic flow based on the estimated current amount of accumulation; and includes.

[0012] Specifically, the program according to the present disclosure is a program for causing a computer to function as the controller.

Effects of the Invention

[0013] According to the present disclosure, it is possible to provide a control system, a control method, a controller, and a program that can reduce the inaccuracy of the packet accumulation amount due to non-arrival of the packet accumulation amount notification when the control signal communication for quality control is made wireless.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0015] Hereinafter, 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 examples are merely illustrative, and the present disclosure can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. In the present specification and drawings, components having the same reference numerals are assumed to be the same as each other.

[0016] (Embodiment 1) First, the basic configuration of a conventional control system will be described. FIG. 1 is a diagram for explaining a conventional control system 300. The control system 300 is a control system that controls the traffic of the wireless network 15, and terminals 11 and access points 12 that transmit packets to each other via the wireless network 15, and a controller 13 that performs transmission control on the terminals 11 and access points 12 via the wireless network 16, and is provided with The controller 13 determines the transmission time and transmission amount of the transmission packets for each traffic flow based on at least the accumulation amount of the transmission packets for each traffic flow notified from the terminal 11, and notifies these to the terminal 11 and the access point 12.

[0017] In the control system 300 as shown in FIG. 1, by wirelessifying the control signal communication between the terminal 11 and the controller 13 and between the access point 12 and the controller 13, there is no constraint of the wired cable as in the main signal communication between the terminal 11 and the access point 12 via the wireless network 15, and the applicable situations increase. On the other hand, when the control signal communication is wirelessified, the occurrence of packet loss due to external factors, for example, the loss of the packet accumulation amount notification, etc., increases compared to the wired case.

[0018] In the control system 300, an example of the case where packet loss occurs will be described with reference to FIGS. 2 and 3. In FIGS. 2 and 3, among the buffers of the terminal 11#N, the buffer #M with the buffer number #M and, among the buffers of the access point 12, the buffer #K with the buffer number #K will be used for the description. FIG. 2 shows an example in the control system 300 shown in FIG. 1 where the terminal 11#N notifies the controller 13 of the accumulation amount of the transmission packets accumulated in the buffer #M at a fixed period t, and the controller 13 schedules the transmission time and transmission time at a period of 5t. Here, the accumulation amount of the transmission packets accumulated in the buffer #M refers to the amount of packets accumulated in the queue of the buffer #M. In FIG. 2, it is assumed that the transmission packets accumulated in the buffer #M of the terminal 11#N are 0 packets at the first notification, 1 packet at the second notification, 3 packets at the third notification, 4 packets at the fourth notification, and 5 packets at the fifth notification. Also, the controller 13 schedules based on the accumulation amount of the last notified transmission packet before performing the scheduling.

[0019] Figure 2 shows the case where the notification from terminal 11#N reaches the controller 13 without any leakage. In Figure 2, five notifications from terminal 11#N arrive before the controller 13 performs scheduling. Therefore, based on the latest accumulation amount informed by the fifth notification, the controller 13 schedules the transmission time and transmission duration for a total of five packets and notifies terminal 11#N of the scheduling. Terminal 11#N transmits the five packets accumulated in buffer #M to the access point 12 according to the notified schedule. In this way, when the notification from terminal 11#N reaches the controller 13 without any leakage, the controller 13 can know the accumulation amount of the transmission packets accumulated in terminal 11 at regular intervals T and can perform appropriate scheduling based on the latest accumulation amount.

[0020] Figure 3 shows the case where packet loss occurs in the fifth notification in Figure 2. In this case, the notification from terminal 11#N to the controller 13 is made only up to the fourth time before the controller 13 performs scheduling. Therefore, the controller 13 will perform scheduling using the past accumulation amount informed by the fourth notification as the latest accumulation amount. That is, due to the lack of notification of the accumulation amount of the transmission packets from terminal 11 and the access point 12 to the controller 13, the controller 13 cannot know the latest accumulation amount. As a result, scheduling is performed based on the inaccurate accumulation amount of the transmission packets, and there is a risk that appropriate scheduling will not be performed.

[0021] Therefore, in the present disclosure, each terminal (11) and access point (12) shall notify the controller (13) of the packet accumulation amount at regular intervals of t. The controller records the latest received packet accumulation amount in the database section. At the same time, in the database section of the controller, the packet accumulation amounts for the past n times used in the past scheduling are stored. The controller performs scheduling based on the latest accumulated packet and the packet accumulation amounts for the past n times recorded in the database section. The controller shall notify the schedule to each terminal and access point at regular intervals of Tc. Each terminal and access point executes packet transmission from the flow unit buffer section according to the received schedule.

[0022] Note that scheduling based on the packet accumulation amounts from the latest to n times before the past is to reduce the deviation from the actual accumulated packet amount by estimating the latest packet accumulation amount from the packet accumulation amounts used in the schedules for the past n times even if packet loss occurs in the notification of the packet accumulation amount.

[0023] FIG. 4 is a diagram for explaining the control system 301 of the present embodiment. The control system 301 connects each terminal 11 and access point 12 to the controller 13, accumulating packets in the buffers (FB1, FB2) for each traffic flow in each terminal 11 and access point 12, or in the buffer within the application, notifying the controller 13 of the accumulated packet amount in advance, determining the transmission time and transmission amount for each traffic in the scheduling section SCH3 of the controller 13, notifying the transmission time and transmission amount from the controller 13 to each terminal 11 and access point 12, and each terminal 11 and access point 12 transmitting packets according to the notified transmission time and transmission amount. It is assumed that the times of the respective terminals 11, access points 12, and controller 13 are synchronized using NTP (Network Time Protocol), PTP (Precision Time Protocol), or the like.

[0024] Specifically, the control system 301 is a control system that controls the traffic of the wireless network 15, including the terminals 11 and access points 12 that transmit packets to each other via the wireless network 15, and a controller 13 that performs transmission control on the terminals 11 and access points 12 via the wireless network 16. It includes: Each of the terminals 11 and access points 12 has buffers (FB1, FB2) that accumulate transmission packets for each traffic flow, and a device-side transmission / reception unit (CTR1, CTR2) that transmits, to the controller 13 at a first period t, the accumulation amount of the transmission packets for each traffic flow accumulated in the buffers (FB1, FB2), and receives, from the controller 13 at a second period T, c the transmission time and transmission amount of the transmission packets for each traffic flow. It also has a main signal transmission unit (MTR1, MTR2) that transmits, according to the transmission time and transmission amount, the transmission packets for each traffic flow in the buffers (FB1, FB2) to the wireless network 15. It includes: The controller 13 receives the accumulation amount from each of the terminals 11 and access points 12 at the first period t, and transmits, to each of the terminals 11 and access points 12 at the second period T, c the transmission time and transmission amount. It has a control-side transmission / reception unit CTR3. It also has a database unit DB that records the latest accumulation amount received by the control-side transmission / reception unit CTR3 and the past accumulation amounts used to determine the past transmission times and transmission amounts. The second period T cEach time, based on the latest accumulation amount and the past accumulation amount recorded in the database unit DB, a scheduling unit SCH3 determines the transmission time and the transmission amount of the transmission packet for each traffic flow. It includes.

[0025] The control system 301 communicates the control signal between the controller 13 and the access point 12 / terminal 11 by a communication means different from the communication means of the main signal (traffic packet). Specifically, the control signal is transmitted and received between the control signal transmission / reception unit CTR1 of the terminal 11 and the control signal transmission / reception unit CTR3 of the controller 13, and between the control signal transmission / reception unit CTR2 of the access point 12 and the control signal transmission / reception unit CTR3 of the controller 13 via the wireless network 16.

[0026] Each terminal 11 and access point 12 notifies the controller 13 of the packet amount accumulated in the flow unit buffer units (FB1, FB2) in the first cycle t as a control signal. The terminal 11 accumulates the packets from each application AP1 in the buffer FB1 for each application (each flow). The packet amount notification unit NTF1 checks the accumulation amount of the transmission packets in each buffer FB1 in the first cycle t (hereinafter, the "accumulation amount of the transmission packets" is abbreviated as the "packet accumulation amount"), and notifies this to the controller 13 via the control signal transmission / reception unit CTR1 as a control signal. Also, the access point 12 accumulates the packets from the upper network device 50 in the buffer FB2 for each application (each flow). The packet amount notification unit NTF2 checks the packet accumulation amount in each buffer FB2 in the first cycle t, and notifies this to the controller 13 via the control signal transmission / reception unit CTR2 as a control signal. Note that the application AP1 may own the flow unit buffer unit FB1.

[0027] 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 the transmission amount for each buffer in the second cycle Tc It is determined by this and notified as a control signal to each terminal 11 and access point 12. Note that the first period t and the second period T c may be the same or different from each other.

[0028] The control signal transceiver unit CTR3 of the controller 13 receives control signals from each terminal 11 and access point 12, and arranges the packet accumulation amount included in the control signal, and information on the terminal 11, access point 12, and flow unit buffers (FB1, FB2) in the database DB.

[0029] FIG. 5 is a diagram for explaining an example of information arranged in the database DB. This database DB arranges the following four pieces of information. The item number is a serial number for all buffers (FB1, FB2) of the terminal 11 and access point 12. The node number is the number of the access point 12 or 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 latest packet accumulation amount held by the buffer having each buffer number notified from each terminal 11 and access point 12, and the packet accumulation amount recorded in the latest column at each of the past n schedulings.

[0030] For example, item number K + 2 is the latest and past n packet accumulation amounts of the flow unit buffer unit FB1#2 of terminal 11#1, and the amount is the latest packet accumulation amount notified from each terminal 11 and access point 12 as "B 12_0 ", the packet accumulation amount recorded in the "latest" column at the previous scheduling as "B 12_1 ", the packet accumulation amount recorded in the "latest" column at the scheduling two times before as "B 12_2 ", and the packet accumulation amount recorded in the latest column at the scheduling n times before as "B 12_nIt is represented as “”. That is, in FIG. 5, among the subscripts of B representing the packet accumulation amount, the first number from the left represents the node (0 is the access point, 1 to N are the terminals), the second number from the left represents the buffer number, and the third number from the left represents the scheduling time when the packet accumulation amount is used as the latest one (the packet accumulation amount to be used for scheduling from now on is 0, and the packet accumulation amounts recorded in the “latest” column at the scheduling times from 1 time ago to n times ago are 1 to n respectively).

[0031] Here, each time the controller 13 performs scheduling, it shifts the packet accumulation amounts recorded in the packet amounts shown in FIG. 5 one column to the right and records them. For example, the packet amount described in the “latest” column is shifted to the “1 time ago” column and recorded when scheduling is performed once. Also, the packet accumulation amount recorded in the “nth time” column is discarded when scheduling is performed. And in the “latest” column, the latest notified packet accumulation amount is always recorded.

[0032] The scheduling unit SCH3 of the controller 13 uses the scheduling method described later to determine the transmission time and transmission amount for each buffer from the contents of the database unit DB. Then, the scheduling unit SCH3 transmits the determined transmission time and transmission amount as control signals from the control signal transceiver unit CTR3 to the terminal 11 and the access point 12.

[0033] Here, when the scheduling unit SCH3 of the controller 13 determines the transmission time and transmission amount for each buffer, it estimates the packet accumulation amount for each buffer by taking the average of the packet accumulation amounts from “latest” to “n times ago” for each buffer recorded in the database unit DB shown in FIG. 5. Hereinafter, regarding the calculation method of the average of the packet accumulation amounts, taking the buffer #M whose buffer number of the terminal 11#N is M as an example, it will be described using the packet accumulation amounts recorded in the row of the item number “K + L + ··· + M” in FIG. 5.

[0034] The scheduling unit SCH3 is the average value B of the packet accumulation amount NMIt may be calculated by a simple moving average using Expression (1-1).

Number

Number

Number

[0035] Note that in the real communication world, the packet transmission amount changes every moment, and due to this change, the value as information is lost as time goes by (= the closer to the present, the higher the reliability of the information as information). Therefore, when actually applying, it is desirable to apply a weighted moving average or an exponential moving average that treats the value of the accumulated packet amount as smaller as it goes back in the past and reduces the value of old information for calculation. Also, the above-described method for calculating the average of the packet accumulation amount is an example and is not limited thereto.

[0036] Each terminal 11 and access point 12 take out the packets accumulated in the flow unit buffer units (FB1, FB2) based on the notified transmission time and transmission amount and input 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.

[0037] FIG. 6 is a diagram illustrating the above-described operations in a flowchart. The control method of the present embodiment is a control method for controlling the traffic of the wireless network 15, The control method is transmission control performed by the controller 13 via the wireless network 16 for the terminal 11 and the access point 12 that mutually transmit packets via the wireless network 15, accumulating transmission packets for each traffic flow in respective buffers (FB1, FB2) of the terminal 11 and the access point 12 (steps S111, S112, S121, S122), transmitting, to the controller 13, the accumulation amount of the transmission packets for each traffic flow accumulated in each of the buffers at a first period t (steps S113, S123), recording, by the controller 13, the latest accumulation amount received from each of the terminal 11 and the access point 12 at the first period t and the past accumulation amount as shown in FIG. 5 (step S131), A second period T c every time, estimating, by the controller 13, the current accumulation amount based on the recorded latest accumulation amount and the past accumulation amount, and determining the transmission time and transmission amount of the transmission packets for each traffic flow based on the estimated current accumulation amount (step 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, from the respective buffers of the terminal and the access point according to the transmission time and the transmission amount, the transmission packets for each traffic flow to the wireless network 15 (steps S114, S124) is characterized by.

[0038] [Effect] FIGS. 7 and 8 are diagrams for explaining the effects of the control system 301. FIG. 7 is a sequence diagram of the control system 301, and FIG. 8 is a sequence diagram in a conventional communication system without the controller 13. In the figures, “RTS” means Request To Send, and “CTS” means Clear to Send. Also, the solid line means the communication of the main signal, and the broken line means the communication of the control signal.

[0039] As can be seen by comparing FIGS. 7 and 8, the communication operations from the main signal buffers (MB1, MB2) in FIG. 7 are the same as those in FIG. 8. The control system 301 of the present invention can be realized by arranging the controller 13 without modifying the existing communication system. Further, in the communication operation of FIG. 8, since there is no control of the transmission time, problems such as the occurrence of packet collisions and biases in the terminals or access points that can be transmitted occur. However, since the control system 301 of the present invention controls the transmission time for the terminals and access points, the above problems are solved.

[0040] [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 calculates the allocation of bandwidth or time based on the total number of flow unit buffers (FB1, FB2) in which packets are accumulated among the flow unit buffers of the terminal 11 and the access point 12. Hereinafter, the parameters will be described. The number of flow unit buffers in which packets are accumulated for the terminal 11 and the access point 12 combined: n The time of 1 cycle: T [sec] The total main signal transmission limit amount per 1 cycle time: Z [Bytes / sec] The time to transmit the first accumulated packet: t start [sec]

[0041] In this case, The transmission amount S of the flow unit buffer #J J [Bytes] is

Equation

Equation

[0042] Note that the order of the flow unit buffers to start transmission can be, for example, from the younger item numbers arranged in the database unit DB of the controller 13, etc.

[0043] [2] Scheduling considering bandwidth weighting This scheduling method is determined by the number of flow unit buffers in which packets are accumulated and the packet accumulation amount among the flow unit buffers (FB1, FB2) of the terminal 11 and the access point 12. Hereinafter, the parameters will be described. Packet accumulation amount of the flow unit buffer #J: B J [Bytes] Time of 1 cycle: T [sec] Transmission limit amount per 1 cycle time: Z [Bytes / sec] Time required to transmit all packets accumulated in all flow unit buffers: T all [sec] Time to transmit the packet first among the packets accumulated in all flow unit buffers: t start [sec]

[0044] In this case, [Number] If we set Transmission amount S of the flow unit buffer #J J [Bytes] is T all When T ≤ T, [Number] T all When T > T, [Number] Transmission time T of flow unit buffer #J J [sec] is T all When T ≤ T,

Number

Number

Number

Number

[0045] Note that when T all > T, the packets that cannot be transmitted are carried over to the next transmission timing.

[0046] (Embodiment 2) 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 through a network. FIG. 9 shows a block diagram of the system 100. The system 100 includes a computer 105 connected to a network 135.

[0047] Network 135 is a data communication network. Network 135 may be a private network or a public network and can include any or all of (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 spanning city, regional, or national boundaries, or (f) the Internet. Communication is performed via network 135 by means of electronic signals and optical signals.

[0048] Computer 105 includes a processor 110 and a memory 115 connected to processor 110. Although computer 105 is represented herein as a stand-alone device, it is not so limited and may rather be connected to other devices not shown in a distributed processing system.

[0049] Processor 110 is an electronic device composed of logic circuits that respond to and execute instructions.

[0050] Memory 115 is a tangible computer-readable storage medium encoded with a computer program. In this regard, memory 115 stores data and instructions, i.e., program code, that are readable and executable by processor 110 to control the operation of processor 110. Memory 115 can be implemented in random access memory (RAM), a hard drive, read-only memory (ROM), or a combination thereof. One of the components of memory 115 is program module 120.

[0051] Program module 120 includes instructions for controlling processor 110 to execute the processes described herein. Although the operations are described herein as being performed by computer 105 or a method or process or a sub-process thereof, those operations are actually performed by processor 110.

[0052] The term "module" is used herein to refer to a functional operation that can be embodied as either a stand-alone component or an integrated configuration consisting of a plurality of sub-components. Thus, program module 120 can be implemented as a single module or as a plurality of modules operating in cooperation with each other. Further, although program module 120 is described herein as being installed in memory 115 and thus implemented in software, it can be implemented in either hardware (e.g., an electronic circuit), firmware, software, or any combination thereof.

[0053] Program module 120 is shown as already loaded into memory 115, but it may be configured to be located on storage device 140 so as to be loaded into memory 115 later. Storage device 140 is a tangible computer-readable storage medium that stores program module 120. Examples of storage device 140 include a compact disk, magnetic tape, read-only memory, optical storage medium, a memory unit composed of a hard drive or a plurality of parallel hard drives, and a universal serial bus (USB) flash drive. Alternatively, storage device 140 may be a random access memory or another type of electronic storage device located in a remote storage system (not shown) and connected to computer 105 via network 135.

[0054] System 100 further includes data sources 150A and 150B, which are collectively referred to herein as data source 150 and are communicatively connected to network 135. In fact, data source 150 can include any number of data sources, i.e., one or more data sources. Data source 150 includes unstructured data and can include social media.

[0055] System 100 further includes user device 130, which is operated by user 101 and connected to computer 105 via network 135. Examples of user device 130 include input devices such as a keyboard or a voice recognition subsystem that enable user 101 to convey selections of information and commands to processor 110. User device 130 further includes an output device such as a display device or a printer or a voice synthesizer. A cursor control unit such as a mouse, a trackball, or a touch-sensitive screen enables user 101 to manipulate a cursor on the display device to convey further selections of information and commands to processor 110.

[0056] Processor 110 outputs the result 122 of the execution of program module 120 to user device 130. Alternatively, processor 110 can provide the output to a storage device 125 such as a database or a memory, or can provide the output to a remote device (not shown) via network 135.

[0057] For example, a program that performs steps S131 to S133 of the flowchart of FIG. 6 can be used as program module 120. System 100 can be operated as controller 13.

[0058] The term "comprising" or "including" is to be construed as specifying the presence of the features, integers, steps, or components stated therein, but not precluding 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 preclude embodiments having a plurality thereof.

[0059] (Other embodiments) It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. In short, the present invention is not limited to the upper embodiments as they are, and the components can be modified and embodied without departing from the gist thereof at the implementation stage.

[0060] In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Further, components from different embodiments may be appropriately combined.

Explanation of Reference Numerals

[0061] 11: Terminal 12: Access Point 13: Controller 15: Wireless Network 50: 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 300, 301: Control System

Claims

1. A control system for controlling traffic in a wireless network, comprising: terminals and access points that transmit packets to each other via the wireless network; a controller that performs transmission control on the terminals and the access points via the wireless network; wherein each of the terminals and the access points includes a buffer that accumulates transmission packets for each traffic flow; a device-side transceiver that transmits, to the controller in a first period, the amount of transmission packets accumulated for each traffic flow in the buffer, and receives, from the controller in a second period, the transmission time and the amount of transmission packets for each traffic flow; a main signal transmitter that transmits, according to the transmission time and the amount of transmission, the transmission packets for each traffic flow in the buffer to the wireless network connecting the terminal and the access point; wherein the controller includes a control-side transceiver that receives, in the first period, the amount of accumulation from each of the terminals and the access points, and transmits, in the second period, the transmission time and the amount of transmission to each of the terminals and the access points; a database unit that records the latest amount of accumulation received by the control-side transceiver and the amount of accumulation for the past n times used to determine the past transmission time and the amount of transmission; a scheduling unit that, for each second period, estimates the current amount of accumulation based on the latest amount of accumulation recorded in the database unit and the amount of accumulation for the past n times, determines the transmission time and the amount of transmission of the transmission packets for each traffic flow based on the estimated current amount of accumulation, and discards the amount of accumulation n times before the latest amount of accumulation each time the transmission time and the amount of transmission of the transmission packets for each traffic flow are determined; wherein the control system is characterized by the above.

2. The estimation of the current amount of accumulation is performed by taking the average of the latest amount of accumulation recorded in the database unit and the past amount of accumulation. The control system according to Claim 1, characterized by the above.

3. A control method for controlling traffic in a wireless network, wherein the control method is transmission control performed by a controller via a wireless network on terminals and access points that transmit packets to each other via the wireless network. Storing transmission packets for each traffic flow in the respective buffers of the terminal and the access point, Transmitting, to the controller in a first period, the amount of storage of the transmission packets for each traffic flow stored in each of the respective buffers, At the controller, recording the latest amount of storage received in the first period from each of the terminal and the access point and the amounts of storage for the past n times, Every second period, at the controller, estimating the current amount of storage based on the recorded latest amount of storage and the amounts of storage for the past n times, and determining the transmission time and transmission amount of the transmission packets for each traffic flow based on the estimated current amount of storage, Discarding the amount of storage n times before the latest amount of storage each time the transmission time and transmission amount of the transmission packets for each traffic flow are determined, Transmitting the transmission time and the transmission amount from the controller to each of the terminal and the access point, and Transmitting the transmission packets for each traffic flow from the respective buffers of the terminal and the access point to the wireless network connecting the terminal and the access point according to the transmission time and the transmission amount A control method characterized by: The past amount of storage is the amount of storage used to determine the past transmission time and transmission amount. A control method characterized by the above.

4. The estimation of the current amount of storage is performed by taking the average of the recorded latest amount of storage and the past amount of storage. The control method according to claim 3, characterized by the above.

5. A controller for controlling the traffic of a wireless network, The controller is a device that performs transmission control via a wireless network for a terminal and an access point that mutually transmit packets via the wireless network, A control-side transmission / reception unit that receives, in a first period, the amount of storage of transmission packets stored for each traffic flow in the respective buffers of the terminal and the access point, and transmits, in a second period, the transmission time and transmission amount of the transmission packets for each traffic flow to each of the terminal and the access point, A database unit that records the latest accumulation amount received by the control-side transceiver unit and the accumulation amounts for the past n times used to determine the past transmission time and the transmission amount; A scheduling unit that estimates the current accumulation amount based on the latest accumulation amount recorded in the database unit and the accumulation amounts for the past n times every second period, determines the transmission time and the transmission amount of the transmission packet for each traffic flow based on the estimated current accumulation amount, and discards the accumulation amount n times before the latest accumulation amount each time the transmission time and the transmission amount of the transmission packet for each traffic flow are determined; A controller characterized by comprising the above. **Claim 6** The estimation of the current accumulation amount is performed by taking the average of the latest accumulation amount recorded in the database unit and the past accumulation amounts. The controller according to claim 5, characterized by the above. **Claim 7** A program for causing a computer to function as the controller according to claim 5 or 6.

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