KR101358802B1 - System for checking qulity of service in multimedia broadcasting and management method thereof - Google Patents

Abstract

The present invention is to install the quality measuring devices in the nodes of the network in the whole network configuration to provide a multimedia broadcasting service and to measure the quality of service for the MPEG-transmission stream in real time and cause the screen mosaic phenomenon or voice distortion phenomenon, etc. In the case of this network problem, it provides a multimedia broadcasting service quality measurement system and method that can respond quickly by pinpointing where it originated from. According to the present invention, it is possible to manage the quality of the multimedia broadcasting service in real time, and to measure the quality of each node between the subscriber and the service provider in the multimedia broadcasting network configuration to identify the point where the quality deteriorates, screen mosaic phenomenon or voice distortion There is an effect that can pinpoint the cause of the phenomenon.

Description

Multimedia broadcasting service quality measurement system and its management method {SYSTEM FOR CHECKING QULITY OF SERVICE IN MULTIMEDIA BROADCASTING AND MANAGEMENT METHOD THEREOF}

The present invention relates to a system for measuring quality of service in a multimedia broadcasting and a method thereof, and more particularly, to install a quality measuring apparatus at nodes throughout the entire network for providing a multimedia broadcasting service. The present invention relates to a multimedia broadcasting service quality measurement system and a method of managing the same, capable of quickly identifying a cause of a screen mosaic phenomenon or a voice distortion phenomenon and rapidly responding by measuring.

As a recent broadband network, a new representative service is IPTV (Internet Protocol Television). In multimedia broadcasting including IPTV service, service quality management is essential because the service is provided through the Internet where the service quality is not guaranteed.

However, the conventional quality measurement shows only header state information such as loss of transport stream according to a corresponding channel, and there is a lack of detailed evidence data on mosaic phenomenon, voice distortion, and disconnection on an actual user screen. In general, this may be caused by an error in a transport stream due to a delay of a PCR packet in the transport stream. Or it could be caused by encoding issues in the headend, or by delays on IPTV networks.

Therefore, the verification tool for these phenomena is urgently needed, and since the IPTV service is provided through various network configurations, it is becoming an essential requirement because of the network structure. However, there are no instruments that can verify the above phenomena in MPEG verification instruments around the world.

The present invention was devised to solve the above-mentioned problems. In the entire network configuration for providing a multimedia broadcasting service, a quality measurement device is installed at nodes in various places to measure the quality of an MPEG-transmission stream in real time, thereby screen phenomena or voice. The purpose of the present invention is to provide a multimedia broadcasting service quality measurement system and a management method thereof, which are capable of quickly responding by accurately identifying the cause of the distortion and the cause of the network if the cause is a problem.

In addition, another object of the present invention is to perform a quality measurement for each node between the subscriber and the service provider in the multimedia broadcasting network configuration to determine whether the network problem or terminal problem according to the point where the quality is degraded IPTV service that can be managed by each node To provide a quality measurement system and its management method.

To this end, according to a first aspect of the present invention, the multimedia broadcasting service quality measuring system includes: a plurality of service quality measuring apparatuses for measuring a quality of service by analyzing a transport stream received by each node constituting the multimedia broadcasting network; It manages the location of the node where the plurality of service quality measuring devices are installed, receives the quality measured value from each service quality measuring device at regular intervals to identify the network status of each node in real time, and measure from each service quality measuring device And a service quality measurement management device for identifying and displaying a location of a node whose quality of service is degraded and a cause of degradation according to the result.

According to a second aspect of the present invention, the method for managing quality measurement of a multimedia broadcasting service of the present invention periodically measures the quality of the multimedia broadcasting service using each service quality measuring device installed in a plurality of nodes constituting the multimedia broadcasting network. Measuring; Receiving and uploading a result value measured by each service quality measuring apparatus and detecting a location of a node whose quality of service is deteriorated by the uploaded result value; And analyzing the cause of the deterioration of the quality of the service.

According to the present invention, since the quality of the multimedia broadcasting service can be measured in real time, quality control can be achieved in real time.

In addition, the present invention, by measuring the quality of service for each node between the subscriber and the service provider in the multimedia broadcasting network configuration to identify the point where the quality deterioration and infer the cause of the screen mosaic phenomenon, voice distortion phenomenon, etc. There is. In addition, since each node can take action, it provides the effect of providing high quality of service (QoS) for the multimedia broadcasting network.

1 is a diagram illustrating a network configuration of a service quality measurement system according to the present invention.
2 is a diagram illustrating an example of installing a service quality measuring apparatus according to the present invention.
3 is a detailed configuration diagram of a service quality measuring apparatus according to the present invention.
4 is a diagram illustrating a packet structure of a transport stream.
5 is a flowchart illustrating the service quality measurement management method of the present invention as a whole.
FIG. 6 is a flowchart for explaining a detailed method of measuring a service quality of FIG. 5.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The configuration of the present invention and the operation and effect thereof will be clearly understood through the following detailed description. Before describing the present invention in detail, the same components are denoted by the same reference symbols as possible even if they are displayed on different drawings. In the case where it is judged that the gist of the present invention may be blurred to a known configuration, do.

1 is a diagram illustrating a network configuration of a service quality measurement system according to the present invention, and FIG. 2 is a diagram illustrating an example in which a service quality measurement apparatus according to the present invention is installed in an IPTV network.

The multimedia broadcasting service quality measurement system according to the present invention includes a plurality of service quality measurement apparatuses 100 and a service quality measurement management apparatus 200.

The plurality of service quality measuring apparatuses 100-1 to 4: 100 are installed in the service providing server unit 10 for providing a multimedia broadcasting service to measure the quality of a transport stream for a broadcast channel, as well as the service providing server. It may be installed in a plurality of nodes (node) configured between the unit 10 and the subscriber (40).

The plurality of nodes configured between the service providing server unit 10 and the subscriber 40 may include an IP backbone network 20, network distribution equipment including an AR (aggregation router: regional offices), and an ONU (Optical Network Unit). 30). Referring to FIG. 2, a node in which the service quality measuring apparatus 100 may be installed is indicated by an arrow in the overall IPTV network configuration. Looking at the right side, the service quality measuring apparatus 100 is an IPTV server (headend), each major regional router in the IP backbone network (Gangnam, Dongjak, Songpa, Seongbuk, Seodaemun, etc.), each country by region (AR), subscriber distribution device It can be installed in L2 or DSLAM (Digital Subscriber Line Access Multiplexer) located at home or apartment.

The plurality of service quality measuring apparatuses 100 installed as described above measure the quality of service for the transport stream by analyzing the transport stream received by each node and measuring the delay of the transport stream. Specific methods and configurations for measuring the quality of service are described in detail below.

The service quality measurement management apparatus 200 records and manages the locations of nodes in which the plurality of service quality measurement apparatuses 100 are installed and manages them integrally.

In addition, the service quality measurement management apparatus 200 receives the quality measurement values regularly from each service quality measurement apparatus 100 and analyzes the collected and collected data to manage the nation's quality data. It can show the deteriorating node of the quality of service.

In addition, the service quality measurement management apparatus 100 may grasp the network state change of each node in real time when receiving the quality measurement value periodically from each service quality measurement apparatus 100. In addition, the service quality measurement management apparatus 200 may accurately determine whether a node having a low service quality is a network problem or a terminal problem.

For example, when a failure occurs in the service providing server unit 10, it is determined that a failure occurs in lower nodes that are expanded and distributed step by step from the service providing server unit 10. If a quality degradation occurs in a router, it may be considered a network problem in a specific region. If it is not a network problem in a specific area, the problem can be determined by the problem of the terminal.

3 is a diagram illustrating a detailed configuration of a service quality measuring apparatus according to the present invention. For reference, the packet structure of the transport stream of FIG. 4 will be described with reference.

As illustrated in FIG. 4, the transport stream TS includes a header including program information, program time information, control information, and the like that constitute each transport stream, and a payload including stream data. It consists of a packet unit of a certain length (188 bytes).

The TS depacketizer 110 reads the packetized transport stream, extracts PCR data from the adaptation field (Adaption_field) included in the header of the transport stream, and extracts PES packet data included in the payload of the transport stream. do.

In order to extract PCR data, the TS depacketizer 110 removes a header portion of a transport packet having a PAT (Program Association Table) having an ID (PID) value of 0 in each transport stream (TS). After extracting only the part corresponding to the data (hereinafter referred to as PAT data), the header part having the ID (PID) value of the PMT (Program Map Table) is removed from this PAT data, and only the part corresponding to the data (hereinafter referred to as PMT data) The PCR data is extracted from the extracted PMT data.

Here, the PCR data is information including a time reference value relative to a program constituting the transport stream, and when the decoder decodes the transport stream, the PCR data is set to a reference time value of a program to be currently decoded.

Packetized Elementary Stream (PES) packet data refers to data obtained by cutting an elementary stream (ES) obtained by converting a video stream and an audio stream of a transport stream into an MPEG, and attaching a header to form a pack.

The PES depacketizer 120 analyzes the PES packet data extracted from the TS depacketizer 110 into PES headers and PES data, transfers the PES headers to the PTS / DTS extractor 150, and the PES data is ES. Transfer to the buffer 130.

The PTS / DTS extractor 150 extracts the PTS data and the DTS data from the PES header and transmits the PTS data and the DTS data to the ES decoder 140 for decoding. PTS (Presentation Time Stamp) data is for synchronizing video ES and audio ES, which is important when screen distortion or channel zapping. Decoding Time Stamp (DTS) data is data indicating the time point at which the video ES decodes. PTS data and DTS data are composed of 33-bit fields expressed in units of 90 KHz.

The ES buffer 130 buffers the PES data extracted from the PES depacketizer 120 to the ES decoder 140.

In addition, the decoder clock synchronizer 170 sets a time to decode using time information coded in encoding, that is, PCR data, so that the time in encoding is synchronized and used in decoding. Here, the time to decode is called a system clock.

At this time, since the PCR data is sampled at 27 MHz by the encoder (9 bits), in order to synchronize the PTS data and the DTS data (33 bits) expressed in 90 KHz (= 27 MHz? 300) units, the PCR counter is synchronized with the system clock. The frequency is sampled and converted into 33 bits.

Then, the quality calculator 160 is a comparator, and compares the PTS data and the DTS data extracted by the PTS / DTS extractor 150 with the PCR data converted by the decoder clock synchronizer 170 and the mutual data is added. The data is transferred to the ES buffer 130 until the same value is buffered before decoding.

Therefore, the ES decoder 140 sets the PCR data converted by the decoder clock synchronizer 170 as a reference time value of a program to be currently decoded, and when the set reference time value, PTS data, and DTS data are synchronized, the ES buffer. The video ES and the audio ES, which are buffered from the 130 and receive the PTS data and the DTS data, which are set and received, are decoded.

For example, if the PCR data converted through the decoder clock synchronizer 170 is 1000 and the DTS data is 2000, the ES decoder 140 must delay decoding by 1000 until the PCR data becomes 2000. That is, after receiving the i-th byte, the ES decoder 140 may delay and decode the time by considering the predetermined system error value 300 / (system_clock_frequency) in the difference value 1000 between the DTS data and the PCR data. will be.

At this time, as the delay time increases, the size of the ES buffer 130 to be managed becomes large.

The quality calculator 160 measures the time interval between the PCR data and the PTS data, the time interval between the PCR data and the DTS data, or the time interval between the PTS data and the DTS data as described above, and the measured time interval is within a certain allowable range. The quality of service is determined by setting the condition to be a quality requirement in advance.

The PCR data may be obtained by using Equation 1 below as data converted through the decoder clock synchronization unit 170.

i: i th byte

t (i): Time when the i th byte is input to the system clock

system_clock_frequency: Ideally 27MHz, ± 810hz variation over time

system_clock_frequency / 300: Expression to convert to 33 bits

% 2 ^ 33: An expression that takes only 33 powers of 2 up to 33 bits.

n: number of buffers

PTS data and DTS data can be measured using Equation 2 below.

td (j): time at which the jth access unit of the ES should be decoded

system_clock_frequency: Ideally 27MHz, ± 810hz variation over time

system_clock_frequency / 300: Expression to convert to 33 bits

% 2 ^ 33: An expression that takes only 33 powers of 2 up to 33 bits.

n: number of buffers

In general, video streams are transmitted in the order of I-pictures, B-pictures, and P-pictures. Since I-pictures and P-pictures have different times at which they should be decoded and reproduced, they can transmit both PTS data and DTS data. In the case of the B-picture, the PTS data and the DTS data are the same because they must be reproduced simultaneously with decoding.

Also, since the audio stream must be sent to the speaker immediately after decoding, PTS data and DTS data are always used as the same.

In the actual packet header, if the PTS data and the DTS data are the same, only the value of the PTS is sent.

In consideration of this transmission method, the quality calculator 160 determines that the service quality is good when the measured time interval is within a certain allowable range, and determines that the service quality is deteriorated when it is out of the predetermined allowable range. If the quality of service is deteriorated, it is possible to determine whether the size of the ES buffer 130 can be optimally increased as described above and provide information on this.

5 is a flowchart illustrating the overall quality measurement management method of the multimedia broadcasting service of the present invention.

First, in order to implement the service quality measurement management method of the present invention, a service quality measurement apparatus is installed in each node constituting the multimedia broadcasting network.

The quality of the multimedia broadcasting service is periodically measured using each of the installed service quality measuring apparatuses (S100).

As a measuring method, as described above, the quality of service may be good or not depending on whether the measured time interval satisfies the quality requirements by extracting PCR data, PTS data, and DTS data from the transport stream and measuring the time interval of each extracted data. Determine whether deterioration or failure occurs.

Thereafter, the service quality measurement management apparatus receives and uploads a result value measured from each service quality measurement apparatus, and detects a position (node) at which the quality of service is degraded based on the uploaded result value (S200).

The detected position can be displayed graphically. In this case, only the location where the quality of service is degraded may be displayed, but all the locations where the service quality measuring apparatus is installed may be displayed, and only the location where the quality of service is degraded may be distinguished and displayed.

Then, the cause of the degradation of the quality of service is analyzed (S300).

For example, if a service quality deterioration occurs in a service providing server unit that provides a multimedia broadcasting service, the quality of service will deteriorate from the service providing server unit to subordinate nodes that are expanded and distributed. If the quality is good but it is degraded at the local router of the transport network, the problem may be analyzed as a problem with the router.

Therefore, through the above process, the present invention can grasp the network state change of each node that provides the multimedia broadcasting service in real time, and accurately determine the cause such as whether the point at which the service quality is degraded is a network problem or a terminal problem. Can be.

FIG. 6 is a flowchart for explaining a detailed method of measuring a service quality of FIG. 5.

FIG. 6 corresponds to the service quality measurement step S100 of FIG. 5 and will be described in connection with the components of FIG. 3 to help the description.

The quality of service measuring apparatus reads the transport stream from the TS depacketizer 110, extracts PCR data included in the header of the transport stream, and extracts PES packet data included in the payload of the transport stream (S110). .

Subsequently, the apparatus for measuring a quality of service analyzes the PES packet data extracted from the TS depacketizer 110 in the PES depacketizer 120 to classify the PES header and the PES data, and separates the PTS data and the DTS data from the separated PES header. Extract. The PTS data and the DTS data are extracted by the PTS / DTS extractor 150 (S120).

At the same time, the PCR data extracted from the transport stream to decode the PTS data and DTS data is sampled using the system clock frequency and converted into 33 bits (S130). This is for synchronizing the PCR data converted into PTS data or DTS data.

Then, the service quality measuring apparatus compares the converted PCR data and the PTS data, or the converted PCR data and the DTS data, the PTS data, and the DTS data by the quality calculator 160 until the mutual data becomes the same value. Transferring to the buffer 130 to be buffered before decoding (S140).

Then, the ES decoder 140 of the apparatus for measuring a quality of quality decodes the video ES and the audio ES based on the PTS data and the DTS data received from the ES buffer 130.

Thereafter, the apparatus for measuring a quality of service measures a time interval measured by the quality calculator 160 by measuring a time interval between PCR data and PTS data, or a time interval between PCR data and DTS data, and a time interval between PTS data and DTS data. The quality of the service is measured according to whether the quality requirement is satisfied (S150). If the quality requirements are satisfied, the service quality is judged to be good. If the quality requirements are not satisfied, the service quality is deteriorated.

The quality requirements are conditions under which the measured time intervals, that is, the time intervals between the PCR data and the PTS data, the time intervals between the PCR data and the DTS data, and the time intervals between the PTS data and the DTS data are within a certain allowable range.

The foregoing description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the spirit of the present invention. Accordingly, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed according to the following claims, and all the techniques within the scope of equivalents should be construed as being included in the scope of the present invention.

100, 100-1,2,3,4: service quality measuring device
200: service quality measurement management device
110: TS Depacketizer
120: PES Depacketizer
130: ES buffer
140: ES decoder
150: PTS / DTS extractor
160: quality calculation unit
170: decoder clock synchronization unit

Claims (10)

A plurality of service quality measuring apparatuses for measuring a quality of service by analyzing a transport stream received by each node constituting the multimedia broadcasting network;
It manages the location of the node where the plurality of service quality measuring devices are installed, receives the quality measured value from each service quality measuring device at regular intervals to identify the network status of each node in real time, and measure from each service quality measuring device A service quality measurement management device for identifying and displaying a location of a node whose quality of service is degraded according to a result, and a cause of degradation;
The plurality of service quality measurement apparatus,
TS (Transmission), which analyzes the transport stream received by each node and extracts PCR (Program Clock Reference) data included in the header of the transport stream and packetized elementary stream (PES) packet data included in the payload of the transport stream. Stream) Depacketizer;
A PES depacketizer for analyzing the PES packet data and extracting a PES header and PES data;
A PTS / DTS extractor for extracting PTS (Presentation Time Stamp) data and DTS (Decoding Time Stamp) data defined in the PES header;
A decoder clock synchronizer configured to frequency-sample the PCR data extracted from the header of the transport stream with the PTS data and DTS data;
An ES (Elementary Stream) buffer buttering until the PCR data converted through the decoder clock synchronization unit and the PTS data or DTS data extracted through the PTS / DTS extraction unit are the same; And
The time interval between the PCR data and the PTS data, the time interval between the PCR data and the DTS data, or the time interval between the PTS data and the DTS data are measured to determine whether the measured time interval satisfies a predetermined quality requirement. And a quality calculation unit for determining a service quality according to the multimedia broadcasting service quality measurement system. The method of claim 1,
Each node constituting the multimedia broadcasting network,
Multimedia broadcasting service quality measurement system comprising a service providing server unit for providing a multimedia broadcasting service, a regional router of a delivery network, regional offices (ARs), distribution centers, and distribution devices (DSLAM, L2) of subscribers.
delete The method of claim 1,
The quality calculation unit
The decoding delay is longer as the measured time interval is longer, so that the size of the ES buffer can be controlled to increase the size of the multimedia broadcasting service measurement system. The method of claim 1,
The quality calculation unit
Multimedia broadcasting service quality measurement system, characterized in that for calculating the PCR data according to the following equation.

i: i th byte
t (i): Time when the i th byte is input to the system clock
system_clock_frequency: Ideally 27MHz, ± 810hz variation over time
system_clock_frequency / 300: Expression to convert to 33 bits
% 2 ^ 33: An expression that takes only 33 powers of 2 up to 33 bits.
n: number of buffers The method of claim 1,
The quality calculation unit
And calculating the PTS data and the DTS data according to the following equation.

td (j): time at which the jth access unit of the ES should be decoded
system_clock_frequency: Ideally 27MHz, ± 810hz variation over time
system_clock_frequency / 300: Expression to convert to 33 bits
% 2 ^ 33: An expression that takes only 33 powers of 2 up to 33 bits.
n: number of buffers As a method of measuring the quality of a multimedia broadcasting service,
Periodically measuring the quality of a multimedia broadcasting service using each service quality measuring apparatus installed in a plurality of nodes constituting the multimedia broadcasting network;
Receiving and uploading a result value measured by each service quality measuring apparatus and detecting a location of a node whose quality of service is deteriorated by the uploaded result value;
Analyzing the cause of the deterioration of the quality of the service;
Detecting the location of the node whose quality of service is degraded,
Graphically display only the positions of the nodes whose quality of service is degraded, or display all the positions of the plurality of nodes where the service quality measuring apparatus is installed, and display only the positions of the nodes whose quality of service is degraded among the plurality of nodes. Is equipped to
Measuring the quality of the multimedia broadcasting service
Extracting PCR data, PTS data, and DTS data from transport streams received by the plurality of nodes;
Determining whether the measured time interval satisfies a quality requirement by measuring a time interval between each extracted data; And
Determining whether the quality of service is good or deteriorated
Quality measurement management method of a multimedia broadcasting service comprising a.
delete delete The method of claim 7, wherein
Measuring the time interval between the extracted data,
And measuring a time interval between the PCR data and the PTS data, a time interval between the PCR data and the DTS data, or a time interval between the PTS data and the DTS data.

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