Controller, communication system, control method, and program

Abstract

The purpose of the present invention is to provide a controller, a communication system, a control method and a program that enable transmission scheduling for multiple wireless networks that avoids mutual interference therebetween.　The controller 13 is characterized by being provided with a scheduler SCH3 which, for each prescribed period, calculates a transmission schedule of packets to transmit from a buffer (FB1, FB2) on the basis of the packet amount stored in a database DB; and which, when calculating the transmission schedule, imposes restrictions such that the total packet amount transmitted from all buffers (FB1, FB2) contained in a network NW#j does not exceed the product of the aforementioned prescribed period and the throughput of each network NW#j.

Description

Technical Field

[0001] The present disclosure relates to a controller for controlling communication of a plurality of access networks, a communication system, a control method, and a program.

Background Art

[0002] In recent years, there has been a growing consideration of accommodating a plurality of services and applications with various network requirements on the same network infrastructure. For this purpose, it is necessary to guarantee the quality required by each service and application accommodated in the same network (NW) in the End-End section from "terminal to terminal" or from "terminal to application server".

[0003] The End-End of the 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 (see, for example, Non-Patent Documents 1 and 2).

[0004] EDCA is a control at the terminal (destination) unit, and it is difficult to perform control in traffic flow units that enable 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] In the transmission control technology of Non-Patent Document 3, the main signal between the terminal and the access point, the controller, and the control signal between them are transmitted and received using different communication means. However, there are currently terminals and access points that have difficulty using multiple wireless networks simultaneously (that is, transmitting and receiving the main signal and the control signal using different communication means), and the technology of Non-Patent Document 3 cannot be applied to such communication systems.

[0007] In addition, when the main signal and the control signal are accommodated in the same wireless network, it is assumed that the communication system will not operate due to the collision of the signals with each other. Specifically, as shown in FIG. 1, when the control signal interrupts at the timing when the main signal is to be transmitted at the timing notified by the scheduler and the packet cannot be transmitted according to the schedule, or conversely, when the main signal that transmits the packet according to the schedule interrupts the periodic communication at the timing when the control signal that communicates periodically is to be transmitted. In such a case, correct scheduling and scheduler notification cannot be performed, and the communication system does not operate.

[0008] That is, in a communication system in which the main signal and the control signal are mixed in the same wireless network, the technique of Non-Patent Document 3 cannot control traffic flow units, and there is a problem that it is difficult to realize quality control in terms of services and applications.

[0009] Therefore, an object of the present invention is to provide a controller, a communication system, a control method, and a program that can realize quality control in terms of services and applications even when the main signal and the control signal are mixed in the same wireless network in order to solve the above problems.

Means for Solving the Problems

[0010] In order to achieve the above object, the controller according to the present invention is configured to collect information from terminals and access points included in the network and calculate a schedule for transmitting the main signal while avoiding the transmission timing of periodic control signals.

[0011] Specifically, the controller according to the present invention is a controller that controls the traffic of a wireless network, the wireless network has one access point and one or more terminals, and packets are mutually transmitted as main signals between the terminals and the access point, A transceiver that transmits and receives a control signal between the terminal or the access point using the same frequency band as the main signal of the wireless network, A database that stores the amount of packets accumulated in the buffer for each traffic flow of the terminal and the access point received as the control signal, Calculating a transmission schedule for packets to be transmitted from the buffer based on the amount of packets stored in the database for each scheduling period, and when calculating the transmission schedule, adding an upper limit so that the total amount of packets to be transmitted from all the buffers included in the wireless network does not exceed the product of the throughput of the wireless network and the scheduling period, and a period limit for avoiding the transmission and reception period of the control signal, and notifying the terminal and the access point of the transmission schedule via the transceiver, Characterized by comprising.

[0012] Further, a control method according to the present invention is a control method for controlling traffic of a plurality of networks, The wireless network has one access point and one or more terminals, and packets are mutually transmitted between the terminal and the access point as a main signal, Transmitting and receiving a control signal between the terminal or the access point using the same frequency band as the main signal of the wireless network, Storing in a database the amount of packets accumulated in the buffer for each traffic flow of the terminal and the access point received as the control signal, Calculating a transmission schedule for packets to be transmitted from the buffer based on the amount of packets stored in the database for each scheduling period, When calculating the transmission schedule, an upper limit is imposed such that the total packet amount to be transmitted from all the buffers included in the wireless network does not exceed the product of the throughput of the wireless network and the scheduling period, and a period limit for avoiding the transmission and reception period of the control signal is added, and the transmission schedule is notified to the terminal and the access point, which is characterized by performing the above.

[0013] When scheduling the transmission timing of packets, the controller grasps the amount of packets accumulated by each of all terminals and access points, sets an upper limit such that the total packet transmission amount is less than or equal to the product of the throughput and the schedule period, and a period limit for avoiding the transmission and reception period of the control signal, and performs schedule calculation. With this limit, collision between the main signal and the control signal can be avoided. Therefore, the present invention can provide a controller and a control method capable of realizing quality control in units of services and applications even when the main signal and the control signal coexist in the same wireless network.

[0014] The database further stores, for each of the terminal and the access point, a notification period for receiving the control signal from the record of the result of receiving the control signal by the transceiver and the record of transmitting the control signal, and the scheduler can set the period limit based on the notification period.

[0015] The scheduler may set the notification period in advance, notify the terminal and the access point, and set the period limit based on the notification period.

[0016] In addition, a communication system according to the present invention includes the controller, the wireless network having one of the access points and one or more of the terminals.

[0017] Furthermore, the present invention is a program for causing a computer to function as the controller. The data collection device of the present invention can also be realized by a computer and a program, and it is possible to record the program on a recording medium or provide it through a network.

[0018] In addition, the above inventions can be combined as much as possible.

Advantages of the Invention

[0019] The present invention can provide a controller, a communication system, a control method, and a program that can achieve quality control in units of services and applications even when a main signal and a control signal coexist in the same wireless network.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0021] Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, components having the same reference numerals indicate the same components as each other.

[0022] (Embodiment 1) FIG. 2 is a diagram for explaining the communication system of the present embodiment. This communication system includes a controller 13, a wireless network 15 having one access point 12 and one or more terminals 11. It is assumed that the main signal and the control signal communicate via the same wireless network at the same frequency.

[0023] The controller 13 is connected to each terminal 11#n (n is a natural number up to N) and each access point 12, and it is assumed that there are no other network devices. It is assumed that the controller 13 has previously recorded in the database unit DB the throughput of each terminal 11#n to be connected, the access point 12, and the wireless network 15 to which they belong.

[0024] The controller 13 is connected to each terminal 11 and each access point 12. Each terminal 11 and each access point 12 accumulate packets in a buffer for each traffic flow (flow unit buffer units FB1, FB2) or a buffer within the application, and notify the controller 13 of the accumulated packet amount as a control signal at predetermined intervals. Also, it is assumed that the controller grasps the transmission period of the control signal from each terminal 11 and access point 12. The controller 13 records the notified packet accumulation amounts in the database unit DB. The scheduling unit SCH3 of the controller 13 determines the packet transmission schedule (transmission time and transmission amount for each traffic flow) of each flow unit buffer unit (FB1, FB2) based on the information of the database unit DB. At this time, as an upper limit, the scheduling unit SCH3 calculates so that the total packet transmission amount according to the schedule does not exceed the product of the throughput and a predetermined period (schedule period). Also, as a period limit, the scheduling unit SCH3 grasps the communication time of the control signal from the notification period, notification start time, and notification end time of each node in the database DB, and calculates the transmission schedule of the main signal so as to avoid the control signal. Details of the scheduling will be described later. The controller 13 notifies the determined transmission schedule to each terminal 11 and the access point 12. Each terminal 11 and the access point 12 instruct the transmission of packets to each flow unit buffer unit (FB1, FB2) according to the transmission schedule notified by the scheduler units (SCH1, SCH2). Each terminal 11 and the access point 12 transmit packets via the main signal buffer units (MB1, MB2) and the main signal transceiver units (MTR1, MTR2). It is assumed that the times of each terminal 11, each access point 12, and the controller 13 are synchronized using NTP (Network Time Protocol), PTP (Precision Time Protocol), or the like.

[0025] Specifically, the controller 13 is a controller that controls the traffic of the wireless network 15, The wireless network 15 has one access point 12 and one or more terminals 11, and packets are mutually transmitted as main signals between the terminal 11 and the access point 12, A transceiver CTR3 that transmits and receives a control signal to and from the terminal 11 or the access point 12 using the same frequency band as the main signal of the wireless network 15, A database DB that stores the amount of packets accumulated in the buffers (FB1, FB2) for each traffic flow of the terminal 11 and the access point 12 received as the control signal. For each scheduling period, calculating a transmission schedule of packets to be transmitted from the buffers (FB1, FB2) based on the amount of packets stored in the database DB, and when calculating the transmission schedule, adding an upper limit restriction so that the total amount of packets to be transmitted from all the buffers (FB1, FB2) included in the wireless network 15 does not exceed the product of the throughput of the wireless network 15 and the scheduling period, and a period restriction for avoiding the transmission and reception period of the control signal, and notifying the terminal 11 and the access point 12 of the transmission schedule via the transceiver CTR3. A scheduler SCH3 that performs the above. Characterized by comprising.

[0026] This communication system communicates the control signal between the controller 13 and the access point 12 / terminal 11 by the same communication means as the communication means for the main signal (traffic packet). Specifically, the control signal is transmitted and received between the control signal transceiver CTR1 of each terminal 11 and the control signal transceiver CTR3 of the controller 13, and between the control signal transceiver CTR2 of each access point 12 and the control signal transceiver CTR3 of the controller 13.

[0027] Each terminal 11 and each access point 12 notify the controller 13 of the amount of packets accumulated in the flow unit buffer section (FB1, FB2) periodically (for each notification period) as a control signal. The terminal 11 accumulates the packets from each application AP1 in the buffer (FB1#1~FB1#L / FB1#M) for each application (for each flow). The packet amount notification unit NTF1 periodically checks the packet accumulation amount of each buffer (FB1#1~FB1#L / FB1#M) and notifies the controller 13 of this as a control signal via the control signal transceiver CTR1. In addition, the access point 12 accumulates packets from the upper network device 50 in buffers (FB2#1 to FB2#K) for each application (for each flow). The packet amount notification unit NTF2 periodically checks the packet accumulation amounts in the respective buffers (FB2#1 to FB2#K), and notifies the controller 13 of these as control signals via the control signal transceiver CTR2. Note that each application AP1 may own the flow unit buffer section FB1.

[0028] The controller 13 records the notified packet accumulation amounts, information on the terminal 11, the access point 12, and the flow unit buffers (FB1, FB2), determines a transmission schedule (transmission time and transmission amount) for each buffer based on this, and notifies each terminal 11 and each access point 12 as control signals.

[0029] The control signal transceiver CTR3 of the controller 13 receives control signals from each terminal 11 and each access point 12, and arranges information on the packet accumulation amounts, the terminal 11, the access point 12, and the flow unit buffers (FB1, FB2) included in the control signals in the database DB.

[0030] FIG. 3 and FIG. 4 are diagrams for explaining an example of the information arranged in the database DB. This database DB arranges the following three pieces of information in the first information section (see FIG. 3). · Item number: A sequential number for all buffers (FB1, FB2) of the terminal 11 and the access point 12. · Node number: The number n of the access point 12 or the terminal 11. · Buffer number: The number of the buffer FB1 held by each terminal 11, or the number of the buffer FB2 held by the access point 12. · Packet amount: The packet accumulation amount held by the buffer having each buffer number. For example, item number K + 2 is the packet accumulation amount of the flow unit buffer section FB1#2 held by the terminal 11#1 belonging to the wireless network 15, and the amount being “B112” means that.

[0031] This database DB arranges the following three pieces of information in the second information section (see FIG. 4). · Node number: It is the number n of access point 12 or terminal 11. · Notification period: It is the period during which a control signal (for example, a transmission schedule) from the controller 12 to each terminal 11 is notified, or the period during which a control signal (for example, the packet accumulation amount) from each terminal 11 to the controller 12 is notified. · Notification start time: It is the time when the access point 12 or the terminal 11 starts transmitting a control signal. · Notification end time: It is the time when the access point 12 or the terminal 11 finishes transmitting a control signal.

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

[0033] Each terminal 11 and access point 12 takes out the packets accumulated in the flow unit buffer units (FB1, FB2) according to the transmission time and transmission amount of the notified transmission schedule 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.

[0034] FIG. 5 is a diagram explaining the operations described above in a flowchart. The control method of this embodiment is transmission control performed by the controller 13 for each terminal 11 and access point 12 that mutually transmit packets via their respective wireless networks 15, accumulating transmission packets for each traffic flow in the respective buffers (FB1, FB2) of each terminal 11 and access point 12 (steps S111, S112, S121, S122), Transmitting the amount of packets stored for each traffic flow stored in each of the buffers to the controller 13 (steps S113, S123). Based on the amounts received from each of the terminal 11 and the access point 12, the controller 13 determines the transmission schedule of the packets for each traffic flow (steps S131, S132). Transmitting the transmission schedule from the controller 13 to each of the terminal 11 and the access point 12 (step S133), and Transmitting the packets for each traffic flow from the respective buffers (FB1, FB2) of the terminal 11 and the access point 12 to the wireless network 15 according to the transmission schedule (steps S114, S124). It is characterized by the above. However, certain restrictions (upper limit restriction and period restriction) described later are added when determining the transmission schedule.

[0035] [Scheduling method] Here, the scheduling method performed by the scheduling unit SCH13 of the controller 13 will be described. Although the scheduling method may be arbitrary, here, the scheduling method disclosed in Non-Patent Document 3 will be described. [1] Fair scheduling This scheduling method calculates the division of the bandwidth or time by the total number of flow unit buffers in which packets are stored among the flow unit buffers (FB1, FB2) of the terminal 11 and the access point 12. Hereinafter, the parameters will be described. The total number of flow unit buffers in which packets are stored for the terminal 11 and the access point 12 combined: n The time of 1 cycle: T [sec] The total transmission limit amount of the main signal per 1 cycle time: Z [Bytes / sec] The time when the first stored packet is transmitted: t start [sec]

[0036] In this case, The transmission amount S of the flow unit buffer #J J [Bytes] is

Number

Number

Number

[0037] Note that the order of the flow unit buffers to start transmission can be, for example, from the smallest item number sorted in the database unit DB of the controller 13.

[0038] [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. The following explains the parameters. The packet accumulation amount of the flow unit buffer #J: B J [Bytes] The time of 1 cycle: T [sec] The transmission limit amount per 1 cycle time: Z [Bytes / sec] The time required to transmit all the packets accumulated in all the flow unit buffers: T all [sec] The time to start packet transmission first among the packets accumulated in all the flow unit buffers: t start [sec]

[0039] In this case, [Number] If we assume that The transmission amount S of the flow unit buffer #J J [Bytes] is T all When T ≤ T, [Number] T all When T > T, [Number] The transmission time T of the flow unit buffer #J J [sec] is T all When T ≤ T, [Number] T all When T > T, [Number] The transmission time t of the flow unit buffer #J J [sec] is T all When T ≤ T, [Number] T all When T > T, [Number] It is calculated as

[0040] In addition, when T all > T, the packets that cannot be transmitted will be carried over to the next transmission timing.

[0041] [Upper limit] Here, in the schedule calculation performed by the scheduling unit SCH13 of the controller 13, the added upper limit will be explained.

[0042] As a result of scheduling, let the amount of packets to be transmitted from each flow unit buffer section (FB1, FB2) be p i At this time, the total amount of packets P to be transmitted in the scheduling period T can be expressed as follows. [Equation]

[0043] Also, let the throughput TP of the wireless network 15 be defined. The controller 13 always calculates a transmission schedule so that the following relationship holds for any wireless network 15. [Equation A2] T × TP ≥ P

[0044] [Period Limit] The period limit is a limit for avoiding the transmission of the main signal from the transmission and reception period of the control signal in order to avoid collision between the main signal and the control signal in the wireless network 15. For example, as shown in FIG. 6, the time is divided into a main signal transmission period T1 and a control signal notification period T2.

[0045] (Example 1) FIG. 7 is a diagram for explaining this example. In this example, the database DB further stores, for each of the terminal 11 and the access point 12, the notification period for receiving the control signal from the results of receiving the control signal (the amount of packet accumulation notified from the terminal 11 or the access point 12) and the results of transmitting the control signal (the transmission schedule notified to the terminal 11 or the access point 12) by the transceiver CTR3 (see FIG. 4), and the scheduler SCH3 is characterized by setting the period limit based on the notification period .

[0046] In FIG. 7, the horizontal axis represents the elapsed time. The box labeled "Controller" is the control signal I1 for notifying the transmission schedule and the like from the controller 13 to the terminal 11 or the access point 12. The box labeled "Terminal #n" is the control signal I2 for notifying the packet accumulation amount and the like from the terminal 11 or the access point 12 to the controller 13. The left end of each control signal represents the transmission start time, and the right end represents the transmission end time. Also, the period during which the control signal I1 is transmitted is the "schedule notification period", and this becomes the scheduling period. During the schedule notification period, the control signal I2 is transmitted multiple times from each terminal 11. This period is referred to as the "packet amount notification period".

[0047] The period of the control signal I1 and the control signal I2 is the control signal notification period T2, and the period during the control signal notification period T2 is the main signal transmission period T1.

[0048] The controller 13 learns the reception period of the control signal I2 from each terminal 11 and access point 12 connected to itself and records it in the database DB. Specifically, the database DB confirms the packet amount notification period, start time, and end time of each terminal 11 and access point 12 a certain number of times and records the respective average values as shown in FIG. 4. Regarding the control signal I1 transmitted from the controller 13 to each terminal 11 or access point, since it can be set by itself, its set value may be described in the database DB.

[0049] The scheduler SCH3 sets the control signal notification period T2 as a period limit based on the information in FIG. 4 and calculates the above-mentioned transmission schedule in consideration of the above upper limit.

[0050] (Example 2) FIG. 8 is a diagram for explaining this example. The meaning of the horizontal axis and the boxes in FIG. 8 is the same as in FIG. 7. In this example, the scheduler SCH3 is characterized by setting the above-mentioned notification period in advance, notifying the terminal 11 and the access point 12, and setting the above-mentioned period limit based on the above-mentioned notification period.

[0051] The scheduler SCH3 sets the transmission time (notification period, notification start time, and notification end time) capable of transmitting the control signal I2 such as the packet accumulation amount, records it in the database DB as shown in FIG. 4, and notifies each terminal 11 and access point 12 in advance. Also, for the control signal I1 transmitted from the controller 13 to each terminal 11 or access point, the set value set by itself is described in the database DB.

[0052] Each terminal 11 and access point 12 transmit the control signal I2 at the notification start time notified by the control signal I1. The scheduler SCH3 sets the control signal notification period T2 as a period limit based on the information in FIG. 4, and calculates the above transmission schedule in consideration of the above upper limit.

[0053] (Embodiment 2) The controller 13 can also be realized by a computer and a program, and it is also possible to record the program on a recording medium or provide it 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.

[0054] The network 135 is a data communication network. The network 135 can be a private network or a public network, and can include any or all of (a) a personal area network covering, for example, a certain room, (b) a local area network covering, for example, a certain building, (c) a campus area network covering, for example, a certain campus, (d) a metropolitan area network covering, for example, a certain city, (e) a wide area network covering an area that spans city, regional, or national boundaries, or (f) the Internet. Communication is performed by electronic signals and optical signals via the network 135.

[0055] Computer 105 includes a processor 110 and a memory 115 connected to the processor 110. Although the 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.

[0056] The processor 110 is an electronic device composed of logic circuits that respond to and execute instructions.

[0057] The memory 115 is a tangible computer-readable storage medium encoded with a computer program. In this regard, the memory 115 stores data and instructions, i.e., program code, that are readable and executable by the processor 110 to control the operation of the processor 110. The memory 115 can be implemented with a random access memory (RAM), a hard drive, a read-only memory (ROM), or a combination thereof. One of the components of the memory 115 is a program module 120.

[0058] The program module 120 includes instructions for controlling the processor 110 to execute the processes described herein. Although operations are described herein as being performed by the computer 105 or a method or process or a subprocess thereof, those operations are actually performed by the processor 110.

[0059] 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 subordinate 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, program module 120 is described herein as being installed in memory 115 and thus implemented in software, but it is possible to implement it in any of hardware (e.g., electronic circuits), firmware, software, or a combination thereof.

[0060] 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 media, 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.

[0061] System 100 further includes data sources 150A and 150B, collectively referred to herein as data source 150 and 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 unsystematized data and can include social media.

[0062] System 100 further includes a user device 130 that is operated by a user 101 and connected to a computer 105 via a network 135. Examples of the user device 130 include an input device such as a keyboard or a voice recognition subsystem that enables the user 101 to convey selections of information and commands to a processor 110. The user device 130 further includes an output device such as a display device, a printer, or a voice synthesizer. A cursor control unit such as a mouse, a trackball, or a touch-sensitive screen enables the user 101 to manipulate a cursor on a display device to convey additional selections of information and commands to the processor 110.

[0063] The processor 110 outputs the result 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 a memory, or to a remote device (not shown) via the network 135.

[0064] For example, a program that performs steps S131 to S133 of the flowchart in FIG. 3 may be used as the program module 120. The system 100 can be operated as a controller 13.

[0065] The terms "comprising" or "including" are to be construed as specifying the presence of the features, integers, steps, or components stated therein, but not as 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 thus do not preclude embodiments having a plurality thereof.

[0066] (Other embodiments) Note 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 at the implementation stage, the components can be modified and embodied without departing from the gist thereof.

[0067] In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined.

Explanation of Reference Numerals

[0068] 11, 11#1, 11#2: Terminal 12, 12#1, 12#2: Access Point 13: Controller NW#j: Wireless Network 50, 50#1, 50#2: 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 301: Control System

Claims

1. A controller for controlling traffic in a wireless network, wherein the wireless network has one access point and one or more terminals, and packets are mutually transmitted between the terminals and the access point using the main signal, a transceiver that receives control signals from the terminals and the access point at a notification period for each of the terminals and the access point using the same frequency band as the main signal of the wireless network, a database that stores, for each of the terminals and the access point, the amount of packets accumulated in a buffer for each traffic flow of the terminals and the access point received as the control signal, and the notification period, notification start time, and notification end time when the control signal was received, for each scheduling period, calculating a transmission schedule of packets to be transmitted from the buffer based on the amount of packets of the control signals received multiple times from the one terminal stored in the database or the control signals received multiple times from each of the plurality of terminals, adding an upper limit so that the total amount of packets to be transmitted from all the buffers included in the wireless network does not exceed the product of the throughput of the wireless network and the scheduling period, and notifying the terminals and the access point of the transmission schedule via the transceiver, a scheduler that performs the above, comprising, the scheduler, using the notification period, notification start time, and notification end time stored in the database, predicting the notification start time for notifying the control signal for each of the terminals and the access point, calculating the transmission schedule for each of the terminals and the access point so as to avoid the predicted notification start time, a controller characterized by the above.

2. The controller according to claim 1, and a wireless network having one of the access points and one or more of the terminals, a communication system comprising.

3. A control method executed by a controller for controlling traffic in a plurality of wireless networks, wherein the wireless network has one access point and one or more terminals, and packets are mutually transmitted between the terminals and the access point using the main signal, Receiving control signals from the terminal and the access point at a notification period for each of the terminal and the access point, using the same frequency band as the main signal of the wireless network; Storing, for each of the terminal and the access point, in a database, the amount of packets accumulated in the buffer for each traffic flow of the terminal and the access point received as the control signal, and the notification period, notification start time, and notification end time at which the control signal was received; Calculating, for each scheduling period, a transmission schedule of packets to be transmitted from the buffer based on the amount of packets of the control signal received multiple times from the one terminal stored in the database or the control signals received multiple times from each of the plurality of terminals; When calculating the transmission schedule, adding an upper limit so that the total amount of packets to be transmitted from all the buffers included in the wireless network does not exceed the product of the throughput of the wireless network and the scheduling period; When calculating the transmission schedule, predicting, for each of the terminal and the access point, the notification start time for notifying the control signal using the notification period, notification start time, and notification end time stored in the database, and calculating the transmission schedule for each of the terminal and the access point so as to avoid the predicted notification start time; and Notifying the transmission schedule to the terminal and the access point. A control method characterized by performing the above.

4. A program for causing a computer to function as the controller according to Claim 1.

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