KR100586229B1 - VOD SERVICE SYSTEM AND METHOD FOR PROVIDING THE QoS WITH LOSS RATIO - Google Patents

Abstract

The present invention relates to a system and method for providing a VOD service, and analyzes a report transmitted from a terminal connected to a server to a server, calculates a loss rate, determines a predetermined level as an index, and determines a loss ratio. Accordingly, QoS is provided to reduce the transmission bit-rate by adjusting the configuration of the video frame of the VOD image provided from the server to the terminal and using the enhancement layer function of temporal scalability. It is to provide a system and method for providing VOD services.

VOD service, loss rate, QoS, wireless network, time hierarchy, senior layer

Description

VOD SERVICE SYSTEM AND METHOD PROVIDING PROVIDING PROVIDING PROVIDING THE QoS WITH LOSS RATIO

1 is a schematic block diagram of a system for providing a VOD service according to an embodiment of the present invention.

2 is a flowchart illustrating an operation of a VOD service providing system according to an embodiment of the present invention.

3 is a flowchart illustrating an operation of a QoS service unit according to an embodiment of the present invention.

The present invention relates to a system and method for providing a VOD service. Specifically, when performing a VOD service using a wireless network, QoS (Quality) for guaranteeing a certain level of service quality and continuity of service regardless of a change in wireless network state is provided. It relates to a VOD service providing system and method for providing a (of QoS).

In recent years, with the development of information and communication technology and computers, the Internet has been rapidly developed to provide not only texts and pictures but also videos through the Internet. In addition, unlike the existing pay per view (PPV) service, which requires ordering and waiting for a program, a bidirectional video service, that is, a VOD service, in which subscribers can instantly select and watch a desired program at a desired time, is being provided.

However, when providing a VOD service using a wireless network, degradation of service quality and service interruption due to data loss or a change in the state of the wireless network cannot be avoided without applying QoS due to the characteristics of the wireless network. to be. However, due to the nature of the wireless network, only the QoS of the network itself is difficult to solve the above problems.

Accordingly, the present invention is to solve the above-mentioned problems, by analyzing a report transmitted from the terminal connected via the wireless network to the server to calculate the loss rate to determine a constant level as an indicator, the loss ratio (loss ratio) QoS of reducing transmission bit-rate is provided by adjusting the configuration of video frame of VOD video provided from the server to the terminal and using the enhancement layer function of temporal scalability. It is to provide a VOD service providing system and method.

The VOD service providing system according to the characteristics of the present invention for achieving the above object

In a VOD system that provides a VOD service to a user terminal connected to a wireless network,

A report receiving unit which receives a report of the terminal on a VOD service provided through the wireless network at the request of the terminal and extracts information on the amount of packets received by the terminal;

 A loss rate calculator for calculating a loss rate with reference to the packet amount received by the terminal and the packet amount sent to the terminal;

A QoS service unit which determines the number of video frames constituting a video frame of a VOD video transmitted to a terminal according to the loss rate; And

And a VOD service unit for transmitting the VOD service requested by the user to the terminal with reference to the determined number of image frames.

In this case, the QoS service unit determines a class according to a loss rate, and omits and transmits an image frame constituting a video frame of a VOD image transmitted according to the class one by one.

In addition, as the loss rate increases, the number of video frames to be omitted increases, and the video frames are omitted from the rear.

VOD service providing system according to another feature of the present invention

In a VOD system that provides a VOD service to a user terminal connected to a wireless network,

A report receiving unit for receiving a report of the terminal on a VOD service provided through the wireless network according to a request of the terminal and extracting information on a packet amount received by the terminal;

 A loss rate calculator for calculating a loss rate with reference to the packet amount received by the terminal and the packet amount sent to the terminal;

A QoS service unit which simultaneously reduces the transmission bit-rate according to the loss rate and simultaneously determines the number of video frames constituting a video frame of a VOD video transmitted to the terminal; And

And a VOD service unit for transmitting the VOD service requested by the user to the terminal with reference to the determination made by the QoS service unit.

In this case, the transmission bit-rate reduction may be performed when the loss rate is maximum.

VOD service providing method according to another aspect of the present invention

In providing a VOD service to a user terminal connected to a wireless network,

(a) receiving a report on the VOD service transmitted by the terminal through a wireless network, and extracting information on the amount of packets received by the terminal;

(b) calculating a loss rate with reference to the packet amount received by the terminal and the packet amount sent to the terminal in step (a);

(c) determining the number of video frames constituting the video frame of the VOD video transmitted to the terminal according to the loss ratio calculated in step (b); And

(d) transmitting the VOD service requested by the user to a user terminal connected to a wireless network with reference to the number of image frames determined in step (c).

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

1 is a schematic block diagram of a system for providing a VOD service according to an embodiment of the present invention.

As shown in FIG. 1, the VOD service providing system 100 includes a report receiving unit 120, a loss rate calculating unit 140, a QoS service unit 160, and a VOD service unit 180.

The report receiver 120 receives a report (RR: Receiver Report) of the terminal 300 for the VOD service previously sent from the VOD service unit 180 to the terminal 300 through the wireless network 200.

The loss rate calculator 140 refers to the report of the terminal 300 received by the report receiver 120. More specifically, the loss rate calculator 140 refers to the packet amount P2 received by the terminal 300 among the reports of the terminal 300 received by the report receiving unit 120. That is, the loss ratio is determined according to the ratio of the packet amount P2 received by the terminal 300 from the packet amount P1 sent from the VOD service unit 180 to the terminal 300. Is calculated.

% Loss = {1-(P2 / P1)} * 100

Thus, for example, if the packet amount P1 sent from the VOD service unit 180 to the terminal 300 is 100 and the packet amount P2 received from the terminal 300 is 100, the loss rate is 0% at the terminal 300. It can be seen that all data was received without loss on the way.

Subsequently, the QoS service unit 160 determines a QoS service to be provided according to the loss rate calculated by the loss rate calculator 140, and the VOD service unit 180 refers to the QoS determined by the QoS service unit 160. It provides a VOD service to the terminal 300.

2 is a flowchart for explaining the operation of the VOD system according to an embodiment of the present invention.

First, when the user requests the start of the VOD service to the system 100 using the terminal 300 connected through the wireless network 200, the system 100 according to the request, the VOD service unit of the system 100 ( In step S100, the user requests a VOD service requested by the user to the terminal 300 through the wireless network 200. The terminal 300 transmits a report (RR: Receiver Report) sent by the VOD service unit 180 to the system 100 through the wireless network 200 (S120). The report includes information on the packet amount P2 received by the terminal 300. Meanwhile, the report receiving unit 120 of the VOD system 100 extracts information on the packet amount P2 received by the terminal 300 from the report transmitted by the terminal 300 and sends the information to the loss rate calculating unit 140 (S140). ). Subsequently, the loss rate calculator 140 calculates a loss rate of the current VOD service providing system 100 using the packet amount P2 received by the terminal 300 and the packet amount P1 transmitted from the VOD service unit 180. (S160). The loss rate may be calculated with reference to Equation 1 as described above with reference to FIG. 1. Subsequently, the QoS service unit 160 determines a grade for each loss rate by selecting a plurality of loss rates based on a plurality of loss rates calculated by the loss rate calculator 140. The number of video frames constituting the video frame of the VOD video transmitted from the VOD service unit 180 to the terminal 300 is determined according to the grade (S180).

Hereinafter, an operation in the QoS service unit 160 of the VOD service providing system according to the embodiment of the present invention will be described with reference to FIG. 3.

3 is a flowchart illustrating an operation of a QoS service unit according to an embodiment of the present invention.

First, a video frame of a VOD image transmitted from the VOD service unit 180 to the terminal 300 includes a plurality of individual image frames, that is, at least one I-frame (Intra-Frame) and a plurality of P-frames. It consists of (P-Frame: Predictive-Frame). I-frames and P-frames are arranged consecutively. Here, the I-frame is a frame having the entire data of the image in one video frame, and the P-frame continuous to the I-frame is the frame having the data of the image changed in the I-frame, and the next consecutive The P-frame is a frame that contains the data of the image changed from the previous P-frame. On the other hand, since the I-frame starts again when the image is greatly changed in the video frame composed of the I-frame and the P-frame, there may be a plurality of I-frames in one video frame. For example, when comparing the frame structure of a moving video such as a sports game and the frame composition of a video having little announcer's movement such as news, more I-frames exist in the sports game video.

Subsequently, in the method of providing a VOD service for QoS service according to an embodiment of the present invention, when the loss rate grade reaches a certain grade using the grade for the loss rate, the P-frame at the far end of the I and P frames constituting the video frame is included. By decreasing in order, even if the state of the wireless network 200 is unstable, the service is not interrupted. In this case, the quality of service may be degraded, but a certain level may be maintained. For example, as the number of P-frames omitted increases, there may be a deterioration in the quality of service such as the movement of the provided video is broken. However, the interruption of the service may be prevented.

First, the QoS service unit 160 checks how the current loss rate grade calculated by the loss rate calculator 140 becomes (S181). Here, if the loss rate is in the range of 20% to 80%, the number of video frames constituting the video frame to be transmitted is adjusted according to a predetermined QoS service order (S182). For example, the QoS service sequence for adjusting the video frame of the VOD image transmitted from the VOD service unit 180 to the terminal 300 according to the loss rate is as follows.

1) Loss Rate 20%: The last P-frame is not sent.

2) Loss rate 40%: Do not send three P-frames from the back.

3) Loss Rate 60%: Transmit I-frame only.

4) Loss rate 80%: Do not transmit intermediate I-frames when I-frames are 1,2,3 ...

However, if the range of the loss rate provided in step S181 is not satisfied, the loss rate grade is checked again. In particular, it is checked whether the loss rate is the maximum loss rate of more than 80% (S183). When the loss rate is maximum, I-frame transmission cannot be achieved. Therefore, if the loss rate is maximized and it is difficult to transmit the I-frame, it is determined that the state of the wireless network 200 is significantly worsened, so that service at the same bit-rate is no longer possible. The server 300 then adjusts the layer level down using a higher layer capability of temporal scalability to provide service at a bit-rate lower than the initial bit-rate ( S184).

In addition, if the loss rate is not the maximum in step S184, the operation in the QoS service unit 160 is terminated.

Accordingly, according to an embodiment of the present invention, the VOD service providing system maintains the best service quality at the same bit rate and increases service efficiency through a QoS service that adjusts the number of video frames constituting a video frame according to the data loss rate. You can.

In addition, it is possible to effectively provide service in any network state by simultaneously applying QoS which lowers bit-rate when loss rate is maximized.

In addition, an example of adjusting the loss rate grade according to the QoS service and the number of video frames according to the loss rate grade according to the embodiment of the present invention described above is not limited to that described in the configuration of the present invention, but is based on network conditions or other conditions. Can be changed accordingly.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the present invention, a QoS service for adjusting the number of video frames constituting a video frame of a VOD video transmitted to a terminal is applied according to a data loss rate for a VOD service provided to a terminal in a VOD system providing a VOD service in a wireless network. Thus, the best service quality can be maintained at the same bit-rate, and the service can be effectively provided.

In addition, when the loss rate is maximized, the service can be effectively provided in any network state by simultaneously applying the QoS of lowering the bit rate.

Claims (21)

In a VOD system that provides a VOD service to a user terminal connected to a wireless network, A report receiving unit which receives a report of the terminal on a VOD service provided through the wireless network at the request of the terminal and extracts information on the amount of packets received by the terminal;  A loss rate calculator for calculating a loss rate with reference to the packet amount received by the terminal and the packet amount sent to the terminal; A frame constituting a class according to the loss rate and transmitting a video frame of the VOD image transmitted according to the class, wherein the video frame includes at least one I-frame and a plurality of P-frames arranged in succession. QoS service unit for determining the number; And VOD service unit for transmitting the VOD service requested by the user to the terminal with reference to the determined number of video frames Including, The QoS service unit determines the number of frames of the video frame by omitting at least one or more P frames when the class according to the loss rate is lower than a set class, and omits all P frames of the video frame when the class is higher than the set class. And selecting a predetermined I frame to determine the number of frames. delete delete The method of claim 1, The I-frame is a VOD system, characterized in that it comprises the entire image information of one frame. The method of claim 1, The P-frame includes only the information changed in the image information of the previous frame. The method of claim 1, The higher the loss ratio is, the greater the number of video frames to be omitted, and in the plurality of consecutively arranged frames, the VOD system, characterized in that is omitted in reverse order from the last arranged frame. The method according to any one of claims 1 to 4 or 5, And a P-frame that is arranged at the end of the video frames constituting the video frame when the grade according to the loss rate is lower than a predetermined grade and transmits. The method of claim 7, wherein And when the grade according to the loss rate is a second grade having a higher loss rate than the first grade, two or more P-frames are skipped and transmitted from the rear of the image frames constituting the video frame. The method of claim 7, wherein When the class according to the loss rate is a third class higher than the set class, only the I-frame of the video frame constituting the video frame is transmitted. The method of claim 9, When the grade according to the loss rate is a fourth grade higher than the third grade, when there are a plurality of I-frames among the image frames constituting the video frame, it is possible to omit and transmit at least one I-frame in the middle. Featured VOD System. In a VOD system that provides a VOD service to a user terminal connected to a wireless network, A report receiving unit for receiving a report of the terminal on a VOD service provided through the wireless network according to a request of the terminal and extracting information on a packet amount received by the terminal;  A loss rate calculator for calculating a loss rate with reference to the packet amount received by the terminal and the packet amount sent to the terminal; A video frame of a VOD image transmitted to the terminal according to the loss rate and at the same time reducing the transmission bit-rate according to the loss rate, the video frame is at least one or more I-frames arranged in succession And a QoS service unit for determining the number of frames constituting the plurality of P-frames; A VOD service unit for transmitting a VOD service requested by a user to a terminal with reference to the decision made by the QoS service unit Including, The QoS service unit determines the number of frames of the video frame by omitting at least one or more P frames when the class according to the loss rate is lower than the set class, and when the class is higher than the set class, all P frames of the video frame are And omit the predetermined number of I frames to determine the number of frames. The method of claim 11, The transmission bit-rate reduction is performed when the loss rate is maximum. delete The method of claim 12, If the loss ratio is the maximum VOD system, characterized in that the I-frame is not transmitted among the video frames constituting the video frame. The method of claim 12, The reduction of the transmission bit-rate uses a temporal scalability (VOD system). In providing a VOD service to a user terminal connected to a wireless network, (a) receiving a report on the VOD service transmitted by the terminal through a wireless network, and extracting information on the amount of packets received by the terminal; (b) calculating a loss rate with reference to the packet amount received by the terminal and the packet amount sent to the terminal in step (a); (c) A video frame is rated according to the loss ratio calculated in step (b), and the video frame is transmitted to the terminal according to the rating, wherein the video frame is arranged in series with at least one I-frame and a plurality of P-frames. Determining the number of video frames that comprise; And (d) transmitting a VOD service requested by a user to a user terminal connected to a wireless network with reference to the number of image frames determined in step (c) Including, Step c) determines the number of frames of the video frame by omitting at least one or more P frames when the grade according to the loss rate is lower than the set grade, and all P frames of the video frame when the loss rate is higher than the set grade. Omits and selects a predetermined I frame to determine the number of frames. The method of claim 16, And in step (c), reduce the transmission bit rate of the VOD service provided to the terminal according to the loss rate. The method of claim 16, And in step (c), combining at least one or more loss rates of step (b) to determine a predetermined grade according to the loss rate. delete The method of claim 16, The number of video frames to be omitted increases as the loss rate increases, and in the plurality of consecutively arranged frames, the VOD service providing method is omitted in reverse order from the last arranged frame. The method of claim 17, The reduction of the transmission bit-rate uses a temporal scalability (VOD) service providing method.

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