KR20090132259A - Apparatus and method for transmitting/receiving multimedia with quality of service - Google Patents

Abstract

PURPOSE: An apparatus and a method for transmitting/receiving multimedia with a service quality assuring function are provided to control an encoding rate and a transmission speed according to the lowest threshold value excess throughput. CONSTITUTION: An information collecting unit(110) collects multimedia processing state information from a plurality of multimedia receiving devices. A control unit(120) produces a throughput to transmission by using the multimedia processing state information of the information collecting unit. The control unit sets an encoding rate and a transmission speed corresponding to the lowest threshold value excess throughput. An encoding unit(130) encodes a multimedia stream according to an encoding rate of the control unit. A multimedia stream transmission unit(140) transmits the encoded multimedia stream with the transmission speed of the control unit.

Description

Multimedia transceiver and method having a service quality assurance function and the method {Apparatus and Method for Transmitting / Receiving Multimedia with Quality of Service}

The present invention relates to a multimedia transmission and reception apparatus having a quality of service guarantee function and a method thereof, and more particularly, a multimedia transmission apparatus for transmitting multimedia data at the same transmission rate transmits a multimedia stream to a plurality of multimedia reception apparatuses, and receives each multimedia. By receiving the multimedia processing status information from the device to calculate the throughput compared to the transmission and then adjusting the encoding rate and the transmission rate according to the lowest threshold throughput, to ensure the quality of service to all receivers whose multimedia throughput exceeds the threshold, A multimedia transceiver having a quality of service guarantee function and a method thereof.

In general, a mobile terminal is a mobile terminal capable of making a wireless call. The analog mobile telephone method (AMPS), first developed at the Bell Labs in the United States in the 1970s, effectively uses a limited frequency resource to prevent the emergence of the mobile phone market. Digital mobile phones, which have appeared since the mid-1980s, have proliferated the mobile phone market by overcoming the limitations of analog systems.

The evolution of the mobile phone service market is generally divided into the first generation analog system, the second generation digital method, and the third generation IMT-2000. Currently, the synchronous CDMA2000, Japan, which has been commercialized for the first time in the world in Korea, is also commercialized for the first time in the world. While 3G mobile communication technology is being spread around W-CDMA, etc., on the other hand, the concept of 4G mobile communication has been newly established while 3G mobile communication technology has failed to achieve the goals of the world's single standard. The development of 4G mobile communication technology is actively underway, not only in the world's standardized organizations, including the International Telecommunication Union (ITU), but also in major developed countries.

Due to the development of such mobile communication technology, various technologies applied to mobile terminals such as multimedia technology, voice recognition technology, and mobile phone positioning technology are rapidly developing. For example, a mobile communication terminal has a color display, a large memory, Advanced features such as digital cameras, wireless Internet platforms, multiplexing, MP3 and VOD features are being adopted. In other words, the development of mobile communication technology and the demands of consumers are accelerating the multimediaization of mobile communication terminals.

Multimedia phones with various multimedia functions have already been released and commercialized through various mobile communication terminal companies at home and abroad.

Hereinafter, a process of reproducing moving image data stored in a conventional mobile terminal on a TV will be described.

In order to play back video data captured by a mobile terminal equipped with a camera and a camcorder function or video data received from a computer, etc. on a TV, an audio / video output terminal provided in the mobile terminal and an external audio / video input provided in the TV are provided. Connect the wired A / V terminal to receive and play the video of the mobile terminal so that you can watch the video data on the TV.

However, in the case of the A / V terminal of the TV is usually located on the back, the connection is inconvenient, and when a call signal is received during video playback, it is inconvenient to make a call.

In addition, although the video data of the mobile terminal can be transmitted to the TV and played back using Bluetooth, in this case, when the video data is transmitted from the mobile terminal, the TV cannot download the entire video data and then play it, so that it cannot be played in real time. Disadvantages arise.

In order to solve this problem, a method and method for reproducing multimedia data using near field communication have been proposed to transmit multimedia data stored or reproduced in a mobile terminal based on near field communication so as to be reproduced in real time.

Such a conventional technology enables a transmitting terminal to scan and select a second terminal capable of transmitting multimedia data, and to perform short-range wireless communication such as a user interface, an ultra wide band (UWB), etc., which receives a command to control the reproduction operation of the multimedia data. Transmitter for transmitting the multimedia data to the second terminal through the Internet, Realtime Transport Protocol (RTP) / RTCP (RTP Control Protocol) for transmitting the multimedia data in real time, the second terminal for transmitting the multimedia data And a first protocol stack including a session protocol for establishing a session, a first format converter for converting a format of the multimedia data into a format supported by the second terminal, a session setup for transmitting the multimedia data, and In addition to controlling real-time transmission, And a control unit for controlling transmission of media data.

In addition, the related art is a receiving terminal for receiving multimedia data transmitted from a first terminal through short-range wireless communication such as ultra wide band (UWB), and RTP (Realtime) for receiving the multimedia data in real time. A second protocol stack including a transport protocol (RTP) / RTP control protocol (RTCP), a session protocol (SP) for establishing a session with a second terminal to receive the multimedia data, and a multimedia data received from the first terminal. A second format conversion unit for converting to a format reproducible in a second terminal, a multimedia playback unit including a video decoder for decoding video data of the received multimedia data and an audio decoder for decoding audio data, and a display for outputting the video data And a speaker for outputting the audio data and the received multi To allow playback of media data in real time and a control section for controlling each section of the second terminal.

In addition, the related art sets up a session between transmitting and receiving terminals to enable the transmission and reception of multimedia data using distance wireless communication, and transmits and receives multimedia data in real time using a real-time transmission protocol between the transmitting and receiving terminals in which the session is set. And, it performs a process of real-time reproduction of the transmitted and received multimedia data in the transmitting and receiving terminal.

In the conventional apparatus and method for reproducing multimedia data using short-range wireless communication, the transmitting terminal transmits the multimedia data at a fixed encoding rate and transmission rate regardless of the multimedia data processing state at the receiving terminal, or only in consideration of a network environment. There is a problem in that the transmission efficiency is lowered because data is transmitted.

In addition, according to the related art, in the environment in which the transmitting terminal transmits the multimedia data to the plurality of receiving terminals at the same transmission speed, the transmitting terminal cannot check the multimedia data processing state at each receiving terminal, and thus, the receiving terminal has a certain level of There is a problem that cannot guarantee the quality of service (QoS).

It is an object of the present invention to solve this problem.

Therefore, in the present invention, a multimedia transmitter for transmitting multimedia data at the same data rate transmits a multimedia stream to a plurality of multimedia receivers, receives multimedia processing status information from each multimedia receiver, and calculates a throughput ratio after transmission. The purpose of the present invention is to provide a multimedia transceiver and a method having a service quality assurance function for guaranteeing a quality of service to all receivers whose multimedia throughput exceeds a threshold by adjusting an encoding rate and a transmission rate according to a throughput exceeding a threshold. have.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

An apparatus of the present invention for achieving the above object is a multimedia transmission apparatus having a service quality guarantee function, comprising: information collecting means for collecting multimedia processing status information from a plurality of multimedia receiving apparatuses, respectively; Control means for calculating the throughput versus the transmission rate using the multimedia processing state information collected by the information collecting means, and then setting an encoding rate and a transmission rate corresponding to the lowest threshold throughput rate; Encoding means for encoding the multimedia stream according to the encoding rate set by the control means; And a multimedia stream transmitting means for transmitting the multimedia stream encoded by the encoding means at the transmission rate set by the control means.

According to another aspect of the present invention, there is provided a multimedia receiving apparatus having a service quality guarantee function, comprising: multimedia stream receiving means for receiving a multimedia stream from a multimedia transmitting apparatus; Buffer management means for buffering the multimedia stream received by the multimedia stream receiving means and managing a buffered data amount; Information transmitting means for transmitting the amount of buffering data managed by the buffer managing means to the multimedia transmitting apparatus; And control means for controlling the information transmitting means to periodically transmit the amount of buffering data managed by the buffer managing means to the multimedia transmitting apparatus.

On the other hand, the method of the present invention for achieving the above object, the multimedia transmission method having a quality of service guarantee function, comprising the steps of: collecting multimedia processing status information from each of the plurality of multimedia receiving apparatus; Setting the encoding rate and the transmission rate corresponding to the lowest threshold exceeding throughput after calculating the throughput vs. transmission using the collected multimedia processing state information; Encoding a multimedia stream according to the set encoding rate; And transmitting the encoded multimedia stream at the set transmission rate.

In addition, another method of the present invention for achieving the above object is a method of guaranteeing a quality of service in a multimedia receiving apparatus, the method comprising: receiving a multimedia stream from the multimedia transmitting apparatus; Buffering the received multimedia stream and managing a buffered data amount; And periodically transmitting the amount of buffering data to be managed to the multimedia transmission apparatus.

In the present invention as described above, after the multimedia transmission apparatus for transmitting the multimedia data at the same transmission rate transmits the multimedia stream to the plurality of multimedia receivers, and receives the multimedia processing status information from each multimedia receiver to calculate the throughput ratio compared to the transmission By adjusting the encoding rate and the transmission rate in accordance with the lowest threshold throughput, the quality of service can be guaranteed to all receivers whose multimedia throughput exceeds the threshold.

The above objects, features, and advantages will become more apparent from the detailed description given hereinafter with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention pertains may share the technical idea of the present invention. It will be easy to implement. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an overall configuration diagram of a multimedia transmission and reception apparatus having a service quality guarantee function according to the present invention.

As shown in FIG. 1, the multimedia transmitter 100 encodes a multimedia stream and transmits the multimedia stream to the multimedia receiver 200. Then, the multimedia receiver 200 feeds back the multimedia processing status information. At this time, the wireless communication technology is a high-performance wireless LAN (Ultra Wide Band), UWB (Ultra Wide Band), etc., the multimedia transmitter 100 and the multimedia receiver 200 is 1: N Ad-Hoc based connection Use Of course, it is also possible to use an infrastructure-based connection using an access point (AP).

Here, the multimedia transmission apparatus 100 is an apparatus for encoding and transmitting multimedia data such as a video by MPEG or the like, and is a device capable of varying the encoding rate and transmission rate according to information input conditions, and a plurality of multimedia The same multimedia stream is transmitted to the receiver 200.

In addition, the multimedia transmitter 100 assumes a device to which a limited specification is applied so as to facilitate utilization in a general home environment, and thus transmits a multimedia stream encoded by the plurality of multimedia receivers 200. It supports a single encoding rate and a single transmission rate, and cannot provide different encoding rates and transmission rates according to the multimedia throughput of the multimedia receiver 200.

In addition, the multimedia receiver 200 decodes the multimedia stream transmitted from the multimedia transmitter 100 and outputs it to the multimedia display apparatus 300 such as a TV and a monitor. In this case, the multimedia receiver 200 converts the multimedia stream transmitted from the multimedia transmitter 100 into video and audio signals suitable for the characteristics of the multimedia display apparatus 300 and outputs the converted video and audio signals. In addition, the multimedia receiving apparatus 200 and the multimedia display apparatus 300 may be implemented as a single device.

In addition, the multimedia receiving apparatus 200 may detect and data the basic transmission characteristics such as a transmission rate, an error rate, and a packet loss rate for a communication environment within the wireless communication section with the multimedia transmitting apparatus 10, and feed back the generated information. The information is transmitted to the multimedia transmission apparatus 100 through a transmission channel.

In addition, the multimedia receiver 200 includes a Stream Quality Monitoring (SQM) module, and collects measures for determining a transmission quality for each layer.

Hereinafter, the measures used to identify transmission quality for each layer will be described in detail.

In the application layer, monitoring elements such as 'Packet Inter-Arrival Time', 'Buffer Fill Rate', 'Buffer Drain Rate', 'Buffer Low Water Mark', 'Buffer High Water Mark', 'Current Buffer Level' To use.

'Packet Inter-Arrival Time' is a value representing the difference between the previous transmission time and the current transmission time of the QoS packet, and the sensitivity for determining the change in the transmission rate varies according to the corresponding value.

'Buffer Fill Rate' refers to the number of bytes of packets flowing into the receiver's buffer per unit time, and 'Buffer Drain Rate' refers to the number of bytes transferred from the buffer to the decoder.

'Low / High Water Mark' is a reference value indicating that stable packet transmission is observed in the buffer, and a range of a predetermined size is determined as a stable value in the buffer.

In addition, when the transmission of the multimedia stream to the multimedia receiver 200 through a specific port of the multimedia transmitter 100 starts, the multimedia receiver 200 receives a predetermined period of the multimedia processing status information through another specific port (Packet Inter Arrival Time) is transmitted to the multimedia transmission apparatus 100. At this time, if a predetermined amount or more of the multimedia processing state information is collected, QoS control starts. In addition, when a new connection with another receiver 200 is created, the multimedia transmitter 100 adds and manages it as a 'Linked List Item'.

The encoding rate and transmission rate control process in the multimedia transmission apparatus 100 is as follows.

First, the case of lowering the encoding rate and the transmission rate may include the case where the 'Buffer Fill Rate' of the multimedia receiver 200 exceeds the threshold, and the case where the 'High Water Mark' is received for a predetermined time.

Next, when the encoding rate and the transmission speed are increased, the threshold value does not exceed a predetermined time, and a case where a 'Low Water Mark' is received for a predetermined time.

In addition, the link layer may use RSSI (Received Signal Strength Indication) as a parameter when using radio transmission, and packet error rate (PER) and signal to noise ratio (SNR) may be used as auxiliary parameters. It can be utilized. In other words, the application layer centered on 'Buffer Monitoring' is mainly used, and it is desirable to use the RSSI value auxiliaryly when changing the transmission speed.

Here, even when the RSSI value is low, the buffer side may determine that stable transmission is being made. However, when the RSSI value is low, the transmission rate may be high.

Therefore, if the RSSI value is lower than the reference value, or if the change in the RSSI value for a certain time exceeds a certain criterion, a mechanism to suspend it even if a condition that can increase the transmission speed according to a criterion determined by the application layer is performed. . In addition, the PER and SNR values are used in a similar manner.

In addition, the multimedia transmission apparatus 100 receives feedback information transmitted from the plurality of multimedia reception apparatuses 200, and the multimedia transmission apparatus 100 determines the encoding rate and the transmission speed by using the feedback information. That is, since the multimedia transmission apparatus 100 supports only a single encoding rate and a single transmission rate, the multimedia transmission apparatus 100 receives multimedia processing status information from each multimedia reception apparatus 200, calculates a throughput ratio, and corresponds to the lowest threshold throughput rate. The multimedia stream is transmitted at the encoding rate and the transmission rate.

Thus, smooth multimedia reproduction is possible in the entire multimedia receiver 200 connected to the multimedia transmitter 100.

As a result, when the multimedia transmission apparatus 100 can receive some multimedia receivers 200 in a poor environment or less than a threshold value, the multimedia transmission apparatus 100 determines the encoding rate and the transmission rate based on this. In order to support the multimedia quality over a certain level in consideration of the deterioration of the service quality of the, after setting a threshold for guaranteeing the lowest transmission quality, the multimedia in the harshest environment among the multimedia receiver 200 exceeding the threshold The encoding rate and the transmission rate are determined by the multimedia transmission apparatus 100 based on the transmission quality of the reception apparatus 200.

In addition, for the multimedia receiving apparatus 200 in which the connection state is maintained with the multimedia transmitting apparatus 100 among the multimedia receiving apparatuses below the threshold value, 'I-Frame' among the multimedia data for checking the maintenance of the connection state. 'Send only to keep connected.

In addition, the transmission environment of the multimedia receiver 200 which has maintained only the connection below the threshold is improved, and the multimedia is immediately exceeded when the threshold is exceeded or when the new multimedia receiver 200 which is not connected exceeds the threshold. If the stream is not transmitted and the status is monitored for a certain period of time and the threshold is exceeded, the multimedia stream is transmitted to maintain the stability of the entire network.

In addition, when the transmission environment of each multimedia receiver 200 changes in order to maintain the stability of the overall network, the multimedia transmitter 100 does not rapidly change the encoding rate and the transmission rate according to the change of the transmission quality, and differentiates when the transmission quality is updated. To update.

2 is a block diagram of an embodiment of a multimedia transmission apparatus having a service quality guarantee function according to the present invention.

As shown in FIG. 2, the multimedia transmission apparatus having the service quality guarantee function according to the present invention includes an information collection unit 110 and the information collection unit for collecting multimedia processing state information from a plurality of multimedia reception apparatuses, respectively. After calculating the throughput vs. transmission using the multimedia processing state information collected by 110, the controller 120 and the controller 120 for setting the encoding rate and the transmission rate corresponding to the lowest threshold throughput are set by the controller 120. An encoding unit 130 for encoding the multimedia stream according to an encoding rate, and a multimedia stream transmitting unit 140 for transmitting the multimedia stream encoded by the encoding unit 130 at the transmission rate set by the controller 120. It includes.

Here, the multimedia processing state information collected by the information collecting unit 110 includes the amount of data buffered by the multimedia receiving apparatus 200.

In addition, the control unit 120 decreases the encoding rate and the transmission rate as the calculated lowest threshold throughput exceeds the threshold, and increases the encoding rate and the transmission rate as the distance increases.

As a result, the control unit 120 calculates the throughput ratio of each transmission by using the multimedia processing state information collected from each multimedia receiver, and encodes and transfer rates corresponding to the lowest throughput among the throughput ratios exceeding the threshold. By setting, the transmission of the multimedia stream to the multimedia receiver having a throughput not exceeding the threshold is stopped.

This is to prevent damage to the multimedia receiver that exceeds the threshold due to the multimedia receiver that does not exceed the threshold in the situation that the same transmission speed must be maintained when transmitting the multimedia stream to all multimedia receivers. That is, to ensure the transmission quality of the multimedia stream transmitted to the multimedia receiver that exceeds the threshold.

3 is a flowchart illustrating a service quality guarantee method in a multimedia transmission apparatus according to the present invention.

First, multimedia processing state information is collected from a plurality of multimedia receivers, respectively (301).

Subsequently, the throughput vs. transmission is calculated using the collected multimedia processing state information, and then the encoding rate and the transmission rate corresponding to the lowest threshold throughput are set (302).

Thereafter, the multimedia stream is encoded according to the set encoding rate (303).

Thereafter, the encoded multimedia stream is transmitted at the set transmission rate (304).

4 is a diagram illustrating an embodiment of a multimedia receiving apparatus having a service quality guarantee function according to the present invention.

As shown in FIG. 4, the multimedia receiving apparatus having the service quality guarantee function according to the present invention includes a multimedia stream receiving unit 210 and a multimedia stream receiving unit 210 for receiving a multimedia stream from the multimedia transmitting apparatus 100. A buffer management unit 220 for buffering the multimedia stream received from and managing the amount of buffering data, and an information transmission unit for transmitting the amount of buffering data managed by the buffer management unit 220 to the multimedia transmission apparatus 100 ( 230, and a controller 240 for controlling the information transmitter 230 to periodically transmit the amount of buffering data managed by the buffer manager 220 to the multimedia transmission apparatus 100.

5 is a flowchart illustrating a service quality guarantee method in a multimedia receiving device according to the present invention.

First, a multimedia stream is received from the multimedia transmission apparatus 100 (501).

Thereafter, the received multimedia stream is buffered and a buffered data amount is managed (502).

Thereafter, the amount of buffering data to be managed is periodically transmitted to the multimedia transmission apparatus 100 (503).

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of recording medium that can be read by a computer.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention can be used for multimedia transmission and reception.

1 is an overall configuration diagram of a multimedia transmission and reception apparatus having a service quality guarantee function according to the present invention;

2 is a block diagram of an embodiment of a multimedia transmission apparatus having a service quality guarantee function according to the present invention;

3 is a flowchart illustrating a service quality guarantee method in a multimedia transmission apparatus according to the present invention;

4 is a block diagram of an embodiment of a multimedia receiving apparatus having a service quality guarantee function according to the present invention;

5 is a flowchart illustrating a service quality guarantee method in a multimedia receiving device according to the present invention.

* Explanation of symbols for the main parts of the drawings

100: multimedia transmitter 200: multimedia receiver

Claims (10)

In the multimedia transmission apparatus having a quality of service guarantee function, Information collecting means for collecting multimedia processing state information from a plurality of multimedia receiving apparatuses, respectively; Control means for calculating the throughput versus the transmission rate using the multimedia processing state information collected by the information collecting means, and then setting an encoding rate and a transmission rate corresponding to the lowest threshold throughput rate; Encoding means for encoding the multimedia stream according to the encoding rate set by the control means; And Multimedia stream transmission means for transmitting the multimedia stream encoded by the encoding means at a transmission rate set by the control means Multimedia transmission apparatus having a service quality guarantee function comprising a. The method of claim 1, The control means, The multimedia transmission apparatus having the service quality guarantee function as the lowest threshold throughput exceeded the threshold decreases the encoding rate and the transmission rate, and the further away from the threshold, the encoding rate and the transmission rate increases. . The method according to claim 1 or 2, The multimedia processing state information, And a quality of data buffered in each of the multimedia receiving apparatuses. The method of claim 3, wherein The information collecting means and the multimedia stream transmission means, Multimedia transmission apparatus having a service quality guarantee function, characterized in that the communication with the multimedia receiver through the Ultra Wide Band (UWB) method. In the multimedia transmission method having a quality of service guarantee function, Collecting multimedia processing status information from a plurality of multimedia receiving devices, respectively; Setting the encoding rate and the transmission rate corresponding to the lowest threshold throughput rate after calculating each throughput ratio using the collected multimedia processing state information; Encoding a multimedia stream according to the set encoding rate; And Transmitting the encoded multimedia stream at the set transmission rate. Multimedia transmission method having a quality of service guarantee function comprising a. The method of claim 5, wherein The setting step, Reducing the encoding rate and the transmission rate as the calculated lowest threshold throughput exceeds a threshold; And Increasing the encoding rate and the transmission rate as the calculated lowest threshold throughput exceeds the threshold. Multimedia transmission method having a quality of service guarantee function comprising a. The method of claim 6, The multimedia processing state information, And a quality of data buffered in each of the multimedia receiving apparatuses. In the multimedia receiving device having a quality of service guarantee function, Multimedia stream receiving means for receiving a multimedia stream from the multimedia transmitting apparatus; Buffer management means for buffering the multimedia stream received by the multimedia stream receiving means and managing a buffered data amount; Information transmitting means for transmitting the amount of buffering data managed by the buffer managing means to the multimedia transmitting apparatus; And Control means for controlling the information transmitting means to periodically transmit the amount of buffering data managed by the buffer managing means to the multimedia transmitting apparatus; Multimedia receiving apparatus having a service quality guarantee function comprising a. The method of claim 8, The multimedia stream receiving means and the information transmitting means, Multimedia receiving apparatus having a service quality guarantee function, characterized in that the communication with the multimedia transmitter through a UWB (Ultra Wide Band) method. In the method of guaranteeing the quality of service in a multimedia receiving device, Receiving a multimedia stream from the multimedia transmission device; Buffering the received multimedia stream and managing a buffered data amount; And Periodically transmitting the amount of buffering data to be managed to the multimedia transmission apparatus Quality of service guarantee method in a multimedia receiving device comprising a.

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