JP6827890B2 - Quality control device, communication quality prediction method, and program - Google Patents

Description

The present invention relates to a technique for predicting the communication quality of a network and controlling the quality of services.

It is important for service providers to predict communication quality and perform appropriate control in order to improve the quality of experience of users who use the provided services. For example, in a video distribution service, if high-quality video data is sent / received (downloaded) in an environment with a low transfer speed, playback may be interrupted due to data failure, so those who download low-quality video data instead. However, there are situations in which the quality of experience is increasing.

As one of the methods for predicting and controlling the communication quality, the past communication quality is accumulated in the quality database (hereinafter referred to as the quality DB), and communication is performed using the DB information and the communication environment information of the user who is going to communicate. There is a prior art (Non-Patent Document 1) that predicts and controls quality. When the communication speed is handled by the quality DB in the technology, the communication speed (throughput) in the past actual measurement is collected and the throughput in the communication to be performed is predicted.

Takafumi Okuyama, Takuto Kimura, Satoshi Matsumoto, "Study for Improving Throughput Prediction Method in Video Distribution," IEICE Technical Report, vol.116, no.403, CQ2016-103, pp.75-80 , January 2017

In the prior art, when predicting the throughput of the communication to be performed from now on based on the past communication quality, the past data of a fixed width time division including the time to be predicted is simply averaged and calculated. Therefore, the predicted value may change significantly at the boundary of the time division, and the predicted value and the actual value may deviate before and after the boundary. As a result, the moving image data may be downloaded under control conditions unsuitable for the communication quality, or the perceived quality may deteriorate due to sudden control.

The present invention has been made in view of the above points, and has continuity in the predicted communication quality in a system that predicts the communication quality of the communication to be performed and controls the service based on the past communication quality. The purpose is to provide a technology that makes it possible to do so.

According to the disclosed technology, it is a quality control device that predicts the communication quality used for service control in a system in which a data distribution service is provided via a network.
A collection means that collects the actually measured communication quality, which is the communication quality actually measured at the client terminal using the service, and the communication environment information of the client terminal, and stores it in the quality DB.
Based on the communication environment information in the client terminal that is the target of communication quality prediction, the measured communication quality is acquired from the quality DB, and from the measured communication quality, the first predicted communication is the predicted communication quality in the time division of the predicted target time. The quality and the second predicted communication quality, which is the predicted communication quality in the adjacent time division, are calculated, and the final predicted communication quality used for the service control is calculated using the first predicted communication quality and the second predicted communication quality. and a communication quality prediction means,
The communication quality prediction means uses the difference between the central time of the time division of the prediction target time and the prediction target time, and the difference between the central time of the adjacent time division and the prediction target time. The quality control device is provided, characterized in that the final predicted communication quality is calculated by interpolating between the first predicted communication quality and the second predicted communication quality .

According to the disclosed technology, in a system that predicts the communication quality of future communication based on the past communication quality and controls the service, a technology that makes it possible to give continuity to the predicted value of the communication quality. Provided.

It is a figure which shows the structure of the quality control apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the example of the quality DB table of the quality control apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the hardware configuration example of the apparatus which concerns on 1st Embodiment of this invention. It is a flowchart for demonstrating the operation about the quality collection process of the quality control apparatus which concerns on 1st Embodiment of this invention. It is a flowchart for demonstrating operation about the quality control process of the quality control apparatus which concerns on 1st Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

For example, in the following description, throughput is used as the communication quality, but this is an example, and an index other than throughput (example: delay amount) may be used as the communication quality. Further, in the following description, a video distribution service is given as an example of the service, but this is also an example, and the service to which the present invention can be applied is not limited to the video distribution service. Hereinafter, the first embodiment and the second embodiment will be described.

[First Embodiment]
(Overall system configuration)
FIG. 1 shows the configuration of the video distribution system according to the present embodiment and the flow related to the input / output of information. As shown in FIG. 1, the video distribution system according to the present embodiment includes a quality control server 10, a client terminal 20, and a video distribution server 30. The quality control server 10, the client terminal 20, and the video distribution server 30 are each connected to the network 40, and information can be transmitted and received via the network 40 as shown in the figure.

The network 40 is, for example, any one or a combination of a plurality of Internet, mobile networks, fixed networks, VPNs, and the like. In particular, in the present embodiment, it is assumed that the client terminal 20 connects to the mobile network for communication.

The quality control server 10 is a computer that predicts throughput based on communication environment information and the like collected from the client terminal 20. The video distribution server 30 is a computer that distributes video data to the client terminal 20.

The client terminal 20 is, for example, a PC, a smartphone, a tablet, or the like, and can reproduce the moving image data received from the moving image distribution server 30. Further, the client terminal 20 calculates the throughput in receiving the moving image data, and transmits the throughput and the communication environment information to the quality control server 10. Further, the client terminal 20 executes service control based on the predicted throughput received from the quality control server 10.

Although FIG. 1 shows one video distribution server 30 and one client terminal 20, in reality, there are a plurality of video distribution servers 30 and a plurality of client terminals 20.

(Functional configuration of the device)
As shown in FIG. 1, the client terminal 20 has an actual measurement throughput calculation unit 21 and a service control unit 22. The quality control server 10 has an actual measurement throughput collection unit 11, a throughput prediction unit 12, and a quality DB 13. Note that the function deployment in this embodiment is an example, and is not limited to this as long as appropriate input / output can be exchanged between the functions.

For example, the quality DB 13 may be a DB server provided outside the quality control server 10 and connected to the quality control server 10 by NW. Further, the quality control server 10 may be provided with a service control unit 22 that selects a control condition that maximizes the perceived quality from the predicted throughput and the plurality of control conditions. In this case, the selected control condition is notified to the target client terminal 20.

The actual measurement throughput calculation unit 21 of the client terminal 20 calculates and outputs the actual measurement throughput from the data size of the moving image data received from the moving image distribution server 30 and the time required for reception.

The actual measurement throughput collection unit 11 of the quality control server 10 collects the actual measurement throughput and the user's communication environment information from the client terminal 20 and stores them in the quality DB 13. The actual measurement throughput collection unit 11 receives the actual measurement throughput and communication environment information from the plurality of client terminals 20 and stores them in the quality DB 13.

FIG. 2 shows an example of a table of the quality DB 13. As shown in FIG. 2, the communication environment information includes the communication date and time, the communication method (Wifi (registered trademark), mobile NW), the telecommunications carrier, the cell information of the mobile NW, the connection destination distribution server, the location information, the radio wave strength, and the like. ..

The throughput prediction unit 12 of the quality control server 10 predicts the throughput in the communication to be performed by using the information accumulated in the quality DB 13 and the communication environment information of the client terminal 20 of the user who is going to communicate. Output the predicted throughput (predicted throughput).

The service control unit 22 of the client terminal 20 selects and outputs control conditions that maximize the perceived quality based on the predicted throughput acquired from the throughput prediction unit 12 and the control condition group given in advance. The control conditions are, for example, a resolution, a frame rate, a compression rate, and the like in video distribution.

(Hardware configuration of the device)
Each of the above-described devices (client terminal 20 and quality control server 10 shown in FIG. 1) can be realized by causing a computer to execute a program describing the processing contents described in the present embodiment. That is, the function of the device can be realized by executing a program corresponding to the processing executed by the device using hardware resources such as a CPU and memory built in the computer. The above program can be recorded on a computer-readable recording medium (portable memory, etc.), stored, and distributed. It is also possible to provide the above program through a network such as the Internet or e-mail.

FIG. 3 is a diagram showing a hardware configuration example of the above device according to the present embodiment. The device of FIG. 3 includes a drive device 100, an auxiliary storage device 102, a memory device 103, a CPU 104, an interface device 105, a display device 106, an input device 107, and the like, which are connected to each other by a bus B, respectively.

The program that realizes the processing in the device is provided by, for example, a recording medium 101 such as a CD-ROM or a memory card. When the recording medium 101 storing the program is set in the drive device 100, the program is installed in the auxiliary storage device 102 from the recording medium 101 via the drive device 100. However, the program does not necessarily have to be installed from the recording medium 101, and may be downloaded from another computer via the network. The auxiliary storage device 102 stores the installed program and also stores necessary files, data, and the like.

The memory device 103 reads and stores the program from the auxiliary storage device 102 when the program is instructed to start. The CPU 104 realizes the function related to the device according to the program stored in the memory device 103. The interface device 105 is used as an interface for connecting to a network. The display device 106 displays a programmatic GUI (Graphical User Interface) or the like. The input device 107 is composed of a keyboard, a mouse, buttons, a touch panel, and the like, and is used for inputting various operation instructions.

(Processing flow)
Next, the processing procedure in the configuration shown in FIG. 1 will be described with reference to the flowcharts of FIGS. 4 and 5.

Here, quality control that predicts and controls the throughput by using the quality collection process that accumulates the past measured throughput and the like in the quality DB 13 and the information accumulated in the quality DB 13 and the communication environment information of the user who is going to communicate from now on. The process will be described separately.

<Quality collection process>
The processing procedure in the quality collection process will be described with reference to the flowchart of FIG.

For example, when a user views a moving image on the client terminal 20, the moving image distribution server 30 divides the moving image data into chunk units and intermittently transmits the moving image data to the client terminal 20. The client terminal 20 downloads the moving image data in chunk units (S101).

The actual measurement throughput calculation unit 21 of the client terminal 20 records the chunk data size (chunk size) and the time required for downloading (download time) for each chunk in a memory or the like (S102). The measured throughput calculation unit 21 calculates and outputs the measured throughput by dividing the chunk size by the download time (S103).

The measured throughput collecting unit 11 of the quality control server 10 collects the measured throughput and the communication environment information at the communication date and time corresponding to the measured throughput from the client terminal 20 (S104) and stores it in the quality DB 13 (S105).

<Quality control process>
Next, the processing procedure in the quality control process will be described with reference to the flowchart of FIG.

For example, when a user from now on tries to watch a moving image on the client terminal 20 (S201), the client terminal 20 transmits the communication environment information of the client terminal 20 to the quality control server 10. The quality control server 10 receives the communication environment information and inputs it to the throughput prediction unit 12, and the throughput prediction unit 12 acquires the communication environment information (S202).

The throughput prediction unit 12 searches the quality DB 13 for an entry group of communication environment information similar to the communication environment information acquired in S202. For example, the throughput prediction unit 12 searches for an entry group having the same time division (= time division of the prediction target time) as the communication environment information acquired in S202, the same communication method, the same communication carrier, and the same cell information, and obtains the result. The weighted average value of the throughputs of the entry groups is output as the predicted throughput of the time division (S203). The weighted average here (same for S204) is (5 × 3 + 3) when, for example, the measured throughput: 5 Mbps is obtained from three entries and the measured throughput: 3 Mbps is obtained from two entries. × 2) / 5 is to be calculated.

Next, the throughput prediction unit 12 searches for an entry group of time divisions adjacent to the time division used in S203, the same communication method as the communication method used in S203, the same communication operator, and the same cell information. The weighted average value of the throughputs of the entries is output as the predicted throughput of the time division (S204).

After acquiring the entry group in the time division of the prediction target time and the entry group in the adjacent time division, the prediction throughput of each may be calculated.

The throughput prediction unit 12 weighted and averages the predicted throughput in the time division of the prediction target time and the predicted throughput in the adjacent time division according to the difference between the prediction target time and the central time of both time divisions, and finally It is output as a predictive throughput (S205). That is, the interpolation between the predicted throughput in the time segment of the predicted target time and the predicted throughput in the adjacent time segment is performed using the difference between the predicted target time and the central time of both time segments.

For example, when the predicted throughput of 12:15 is obtained when the time division is set every 20 minutes, first, the predicted throughput T_A of the time division A12:00 to 12:20 of the prediction target time and the adjacent time division B12: Find the predicted throughput T_B from 20 to 12:40. The difference between the central times 12:10 and 12:15 in the time division A is 5 minutes, and the difference between the central times 12:30 and 12:15 in the time division B is 15 minutes. Therefore, the final predicted throughput is obtained by a weighted average of 15/20 × T_A + 5/20 × T_B weighted by the inverse ratio of the difference between the predicted target time and the central time of the time divisions A and B.

The service control unit 22 of the client terminal 20 acquires the final predicted throughput described above from the quality control server 10 and also acquires a control condition group (S206). The control condition group may be acquired from the quality control server 10, those stored in advance in the client terminal 20, or may be acquired from the video distribution server 30.

Then, there are a plurality of service control units 22 when the purpose is to maximize the image quality without causing the reproduction interruption due to the exhaustion of the data accumulated in the buffer in the moving image reproduction of the client terminal 20. For each control condition, for example, for each image quality option, the minimum required throughput (required throughput) for smooth playback without interruption is obtained, and the required throughput and predicted throughput are compared (S207), and the required throughput is obtained. Outputs the control condition that maximizes the perceived quality among the options that do not exceed the predicted throughput (S208). As shown in FIG. 5, the control condition that maximizes the required throughput may be selected from the options in which the required throughput does not exceed the predicted throughput.

The client terminal 20 connects to the video distribution server 30 according to the control conditions and starts chunk download and playback (S209). As described above, S206 to S208 may be executed by the quality control server 10.

The quality collection process may be carried out for each chunk download, or all chunks may be carried out collectively after the viewing is completed. The quality control process may be carried out only at the start of viewing, or may be carried out for each chunk download. The quality control server 10 may calculate and hold the predicted throughput for each communication environment information in advance.

[Second Embodiment]
Next, a second embodiment will be described. The second embodiment is the same as the first embodiment except for the processing of S205 by the throughput prediction unit 12.

In the second embodiment, the throughput prediction unit 12 performs a group of entries of communication environment information similar to the prediction target communication environment information from the quality DB 13, for example, a prediction target, as in S203 in the first embodiment. The entry group of the same time division, the same communication method, the same communication carrier, and the same cell information as the communication environment information is searched, and the weighted average value of the throughput of the obtained entry group is output as the predicted throughput of the time division. Next, as in S204 of the first embodiment, entries with adjacent time divisions, the same communication method, the same carrier, and the same cell information were searched, and the throughputs of the obtained entries were weighted averaged. The value is output as the predicted throughput of the time segment.

Next, the throughput prediction unit 12 sets the value at the central time of both time divisions in each section so that the predicted throughput in the time division of the prediction target time and the predicted throughput in the adjacent time division do not change significantly. As the calculated predicted throughput, using the difference between the predicted target time and the central time of both time divisions, the predicted throughput of the central time of both time divisions is interpolated by, for example, a triangular function or a staircase function, and finally. Output as predicted throughput.

For example, when the predicted throughput of 12:15 is obtained when the time division is set every 20 minutes, first, the predicted throughput T_A of the time division A12:00 to 12:20 of the prediction target time and the adjacent time division B12: Find the predicted throughput T_B from 20 to 12:40. The difference between the central times 12:10 and 12:15 in the time division A is 5 minutes, and the difference between the central times 12:30 and 12:15 in the time division B is 15 minutes. Therefore, the final predicted throughput is (T_A-T_B) × (cos (5/20), assuming that the value at the central time of time division A is T_A and the value at the central time of time division B is T_B and interpolated by the cosine function. It is calculated by × π) + 1) / 2 + T_B. When interpolating with a step function that takes 20 arithmetic progressions, the final predicted throughput is calculated by (T_A-T_B) × (1-5 / 20) + T_B.

(Summary of embodiments)
As described above, according to the embodiment of the present invention, in a system in which a data distribution service is provided via a network, a quality control device for predicting the communication quality used for service control, wherein the service is used. A collection means that collects the measured communication quality, which is the communication quality actually measured at the client terminal to be used, and the communication environment information of the client terminal and stores it in the quality DB, and the communication environment at the client terminal that is the target of the communication quality prediction. Based on the information, the measured communication quality is acquired from the quality DB, and from the measured communication quality, the first predicted communication quality, which is the predicted communication quality in the time division of the predicted target time, and the predicted communication quality in the adjacent time division are used. It is characterized by having a communication quality prediction means for calculating a certain second predicted communication quality and calculating the final predicted communication quality used for the service control by using the first predicted communication quality and the second predicted communication quality. A quality control device is provided.

The quality control server 10, the actual measurement throughput collection unit 11, the quality DB 13, the throughput prediction unit 12, and the throughput are examples of the quality control device, the collection means, the quality DB, the communication quality prediction means, and the communication quality, respectively.

The communication quality prediction means uses the difference between the central time of the time division of the prediction target time and the prediction target time, and the difference between the central time of the adjacent time division and the prediction target time. The final predicted communication quality may be calculated by interpolating between the first predicted communication quality and the second predicted communication quality.

The communication quality predicting means may perform the interpolation by using a weighted average, a trigonometric function, or a step function.

The quality control device may further include a service control means for selecting a control condition that maximizes the perceived quality of the user who uses the service from the final predicted communication quality and a plurality of control conditions. The service control unit 22 is an example of a service control means.

With the above configuration, it is possible to give continuity to the predicted value, and it is possible to solve the problem that the predicted value changes greatly at the boundary of the time division and the predicted value and the actual value deviate before and after the boundary.

Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It is possible.

10 Quality control server 11 Actual measurement throughput collection unit 12 Throughput prediction unit 13 Quality DB
20 Client terminal 21 Actual throughput calculation unit 22 Service control unit 30 Video distribution server 40 Network 100 Drive device 101 Recording medium 102 Auxiliary storage device 103 Memory device 104 CPU
105 Interface device 106 Display device 107 Input device

Claims (6)

A quality control device that predicts the communication quality used for service control in a system in which a data distribution service is provided via a network.
A collection means that collects the actually measured communication quality, which is the communication quality actually measured at the client terminal using the service, and the communication environment information of the client terminal, and stores it in the quality DB.
Based on the communication environment information in the client terminal that is the target of communication quality prediction, the measured communication quality is acquired from the quality DB, and from the measured communication quality, the first predicted communication is the predicted communication quality in the time division of the predicted target time. The quality and the second predicted communication quality, which is the predicted communication quality in the adjacent time division, are calculated, and the final predicted communication quality used for the service control is calculated using the first predicted communication quality and the second predicted communication quality. and a communication quality prediction means,
The communication quality prediction means uses the difference between the central time of the time division of the prediction target time and the prediction target time, and the difference between the central time of the adjacent time division and the prediction target time. The quality control device is characterized in that the final predicted communication quality is calculated by interpolating between the first predicted communication quality and the second predicted communication quality . The quality control device according to claim 1 , wherein the communication quality predicting means performs the interpolation by using a weighted average, a trigonometric function, or a step function. When the service is a video distribution service and the communication quality is throughput, the minimum required throughput for smooth playback without interruption is obtained for each image quality option, and the required throughput and the said The claim is characterized by further comprising a service control means that compares with the predicted throughput, which is the final predicted communication quality, and outputs the image quality that maximizes the perceived quality among the options in which the required throughput does not exceed the predicted throughput. The quality control device according to 1 or 2 . A communication quality prediction method executed by a quality control device that predicts the communication quality used for service control in a system in which a data distribution service is provided via a network.
A collection step of collecting the measured communication quality, which is the communication quality actually measured at the client terminal using the service, and the communication environment information of the client terminal, and storing the information in the quality DB.
Based on the communication environment information in the client terminal that is the target of communication quality prediction, the measured communication quality is acquired from the quality DB, and from the measured communication quality, the first predicted communication is the predicted communication quality in the time division of the predicted target time. The quality and the second predicted communication quality, which is the predicted communication quality in the adjacent time division, are calculated, and the final predicted communication quality used for the service control is calculated using the first predicted communication quality and the second predicted communication quality. and a communication quality prediction step of,
In the communication quality prediction step, the quality control device determines the difference between the central time of the time division of the prediction target time and the prediction target time, and the central time of the adjacent time division and the prediction target time. A communication quality prediction method, characterized in that the final predicted communication quality is calculated by interpolating between the first predicted communication quality and the second predicted communication quality using the difference between the two . The communication quality prediction method according to claim 4 , wherein in the communication quality prediction step, the quality control device performs the interpolation using a weighted average, a trigonometric function, or a step function. A program for causing a computer to function as each means in the quality control device according to any one of claims 1 to 3 .

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