KR100681914B1 - Digital broadcasting system and method using heterogeneous network - Google Patents

Abstract

According to the present invention, in the digital broadcasting, a base layer for transmitting basic frame information uses a first communication network, and an enhancement layer for transmitting extended frame information includes a second type different from that of the first communication network. The present invention relates to a digital broadcasting system and method using a heterogeneous network for transmitting to a terminal using a communication network.

According to the present invention, since basic frame information and extended frame information are transmitted through different communication networks, it is possible to effectively use limited radio resources (digital broadcasting channels) and to use both terminals released in the past and new terminals for high-definition broadcasting. Has an effect.

Description

Digital Broadcasting System and Method Using Different Kinds of Networks

1 is a schematic diagram of a digital broadcasting system using a single network according to the prior art;

2 is a schematic diagram of a digital broadcasting system using a heterogeneous network according to the present invention;

3 is a diagram illustrating a method for forming an enhancement layer using temporal scalability;

4 is a view for explaining a method of forming an enhancement layer using spatial scalability;

5 is a diagram illustrating a method of forming an enhancement layer using temporal and spatial scalability.

<Description of Symbols for Major Parts of Drawings>

100, 110: Digital broadcasting center 200: communication network

210: first communication network 220: second communication network

310: first terminal 320: second terminal

The present invention relates to a digital broadcasting system and method using a heterogeneous network, and more particularly, a base layer for transmitting basic frame information in digital broadcasting such as satellite digital multimedia broadcasting (DMB) may include a first communication network ( For example, an enhancement layer for transmitting extended frame information using a satellite DMB network and a terrestrial DMB network is transmitted to a terminal using a second communication network (eg, Wibro) that is different from the first communication network. The present invention relates to a digital broadcasting system and method using a heterogeneous network.

Referring to the digital broadcasting system according to the related art, as shown in FIG. 1, the digital broadcasting center 100 transmits video information by using a satellite DMB network or a terrestrial DMB network 200, and the like. ) Received and played back the digital broadcast. However, in the digital broadcasting according to the related art, the resolution and frame rate are fixed in the moving picture information transmitted by the digital broadcasting center 100, and the DMB receiving terminals 310 and 320 also have the fixed resolution and frame rate. Video information was received and reproduced through a single network (satellite DMB network / terrestrial DMB network). For example, in the case of the satellite DMB, the conventional satellite DMB has a fixed resolution and frame rate of QVGA (Quater Video Graphics Arry) and 15 fps (frame per second), respectively, and the satellite DMB receiving terminal is also fixed to QVGA and 15 fps. In this way, digital broadcasting can be received.

However, with the development of the technology, user requirements will increase and in this case, the quality of the current QVGA, 15fps will be unsatisfactory for the viewers in the next few years. Thus, in order to provide better resolution and frame rate after several years, the digital broadcasting center needs to modify the video information to be transmitted to high-definition video. A problem that cannot be used anymore occurs.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to provide a heterogeneous network capable of continuously watching in the conventional image quality for the existing terminal and high-definition broadcasting for the new terminal It is to provide a digital broadcasting system and method used.

For this purpose, the digital broadcasting system using a heterogeneous network according to the present invention is classified into basic frame information capable of reproducing basic frames for basic broadcasting and extended frame information capable of reproducing extended frames for high-definition broadcasting, respectively. A digital broadcasting center transmitting over two communication networks; A first communication network transmitting the basic frame information; A second communication network transmitting the extended frame information and different from the first communication network; And a terminal configured to receive basic frame information through the first communication network, receive extended frame information through the second communication network, and output digital broadcasting by combining the basic frame information and the extended frame information. do.

The digital broadcasting method using the heterogeneous network according to the present invention includes the steps of: classifying and transmitting, by the digital broadcasting center, basic frame information capable of reproducing basic frames for basic broadcasting and extended frame information capable of reproducing high quality broadcasting extended frames, respectively; The basic frame information is transmitted through a first communication network, and the extended frame information is transmitted through a second communication network of a different type from the first communication network; Receiving, by the terminal, basic frame information through the first communication network and receiving extended frame information through the second communication network; And outputting, by the terminal, the digital broadcast by combining the basic frame information and the extended frame information.

Preferably, the first communication network is a network specialized for digital broadcasting, for example, a satellite DMB network or a terrestrial DMB network. The second communication network is a conventional commercialized network instead of a professional digital broadcasting network. It is preferable to use the Internet, a wired Internet, a mobile communication network, and the like.

The extended frame information for high quality broadcasting may use temporal scalability, spatial scalability, or temporal and spatial scalability.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. In the following description, the same or similar components are denoted by the same reference numerals as much as possible, and detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention are omitted. For example, a detailed description of a standard or a standard of digital broadcasting can be referred to the standard (standard), so the description thereof is omitted here.

First, FIG. 2 is a schematic diagram of a digital broadcasting system using a heterogeneous network according to the present invention. As shown in FIG. 2, the digital broadcasting system according to the present invention classifies basic frame information and extended frame information, respectively, and transmits them to the first communication network and the second communication network, and transmits the basic frame information. The first communication network 210, the second communication network 220 for transmitting the extended frame information, and the terminal 320 for receiving and combining the basic frame information and the extended frame information to play a video.

The digital broadcasting center 110 generally compresses and transmits a large amount of video information (data) effectively, and as a standard of such video compression technology, the Moving Picture Experts Group (MPEG) of ISO / IEC (International Data Communication / International Electrotechnical Commission) ) And the H.26x series of the International Telecommunication Union-Telecommunication Session (ITU-T). Currently, commercially available digital broadcasting mainly uses "MPEG4" or "H.264 / MPEG4 part 10" proposed by Joint Video Team (JVC), a joint venture of ISO / IEC and ITU-T.

Video compression technology takes advantage of the fact that the statistical characteristics of video data have a lot of spatial and temporal redundancy.In general, a discrete cosine transform (DCT) is performed for each frame to reduce spatial redundancy. In order to reduce temporal redundancy, differential pulse coded modulation (DPCM) is performed to find continuity and similarity between images from a reference image that has been encoded for each frame.

As encoding modes for video compression, there are an intra mode and an inter mode. Intra mode is a mode that converts and encodes based on continuity and similarity included in the original image itself. In addition, the inter mode is a mode for encoding based on continuity and similarity between images, which is a predictive mode that predicts motion from an existing image in time and compares it with the original image to encode a prediction error. It may be classified into a bi-predictive mode, which predicts a motion from an image existing before or after time, and compares it with an original image to encode a prediction error.

Hereinafter, basic frame information and extended frame information transmitted through different communication networks will be described in detail with reference to FIGS. 3 to 5.

Prior to the detailed description, the terminology used in the present invention is simply defined, and the term "basic broadcast" is set by a digital broadcasting standard or standard (per country or region), and the minimum image quality (basic image quality) that can be viewed through a DMB receiving terminal. The term " high quality broadcast " refers to higher quality broadcast with improved resolution and / or frame rate than the basic broadcast.

Taking satellite DMB as an example, the commercially available satellite DMB has a resolution and a frame rate set to QVGA (320 × 240) and 15 fps, respectively. In this case, QVGA / 15 fps is the basic broadcast. However, although not currently commercialized, broadcasts with resolutions up to VGA (640 × 480) and / or frame rates up to 30fps can be transmitted, in which case broadcasts such as QVGA / 30fps, VGA / 15fps, and VGA / 30fps. This will be a high definition broadcast.

3 is a diagram illustrating a method of forming an enhancement layer using temporal scalability.

The base layer transmitted through the first communication network is composed of a plurality of base frames for basic broadcasting. The first frame of the basic frame is processed in the intra mode from the original image, and subsequent frames are mainly processed in inter mode by comparing the continuity and similarity with previous or subsequent frames, or when the continuity and similarity with neighboring frames are low. (Eg, when the scene is switched), it is processed in the intra mode.

Although not shown in detail with reference to FIG. 3, assuming that 'B (0)' is the first frame, since 'B (0)' does not have a frame (reference frame) that can be referred to from the original image itself. It is processed in intra mode, and the nth basic frame 'B (n)' is adjacent to the neighboring basic frames 'B (n-4)', 'B (n-2)', and 'B (n + 2)'. After comparing the continuity and the similarity, the most similar basic frame is processed in the inter mode, or when the continuity and the similarity are low, the process is processed in the intra mode from the original image.

In addition, information that can reproduce the original basic frames using the inter mode or the intra mode is basic frame information, and the digital broadcasting center 110 transmits the basic frame information to the terminals 310 and 320 through the first communication network 210. By transmitting, the terminal can output the reference broadcast. The basic frame information includes encoding mode information representing an encoded mode, reference frame identification information indicating a frame referenced in an inter mode, and prediction error information for motion compensation.

Meanwhile, the digital broadcasting center generates separate extended frame information for broadcasting having a better frame rate than the reference frame. When temporal scalability is used, an extended frame is inserted between the reference frames to improve an hourly frame rate. Referring to FIG. 3, extended frames 'T (n-3)', 'T (n-1)', 'T (n + 1)' is inserted after the basic frames 'B (n-4)', 'B (n-2)' and 'B (n)', respectively, to double the frame rate.

Extended frames forming such an extended layer are processed in an inter mode from a base frame of a base layer or an extended frame of itself (extended layer). Referring to FIG. 3, an extended frame 'T (n + 1)' is a neighboring base. Use frame 'B (n)' or 'B (n + 2)' as reference frame or refer to extended frame 'T (n-3)' or 'T (n-1)' previously located in time The frame is processed in inter mode. In this case, when only the frames located before are referred to in time, the omnidirectional prediction mode is used. As illustrated, when the frames are located before or after time, the bidirectional prediction mode is used. As in the basic frame information, the extended frame information includes encoding mode information, reference frame identification information, and prediction error information.

As described above, the enhancement layer generated based on the base layer is linked to the base layer and is transmitted to the terminal through a second communication network that is different from the first communication network through which the basic frame information is transmitted.

On the other hand, the DMB receiving terminal will determine the broadcast quality that can be reproduced (output) according to its performance (function). For example, if only the basic broadcast can be reproduced like the first terminal 310, only the basic frame information is received. The basic broadcast will be played, and if the high quality broadcast can be played like the second terminal 320, the basic broadcast or the high quality broadcast can be selected and played. Of course, for high quality broadcasting, the second terminal 320 should receive not only the basic frame information transmitted through the first communication network but also the extended frame information transmitted through the second communication network, based on the basic frame information. The base frame and the extended frame must be restored (decoded) by combining the information.

In the case of satellite DMB, the resolution and frame rate are set to QVGA (320 × 240) and 15 fps, respectively, in the basic broadcast, but QVGA / 30fps, QVGA / 45fps, QVGA / 60fps, etc. are applied when the temporal scalability described above is applied. The broadcast will be a high definition broadcast.

4 is a view for explaining a method for forming an enhancement layer using spatial scalability.

Similar to the temporal scalability described above, assuming that B (0) is the first frame, although not shown, 'B (0)' does not exist from the original image itself since there is no reference frame (reference frame). It is processed in intra mode, and the nth basic frame 'B (n)' is adjacent to the neighboring basic frames 'B (n-4)', 'B (n-2)', and 'B (n + 2)'. After continuity and similarity are compared, they are processed in the inter mode from the most similar basic frame or in the intra mode from the original image when the continuity and similarity are low.

Meanwhile, the digital broadcasting center generates separate extended frame information for broadcasting having a higher resolution than the reference frame. In case of using spatial scalability, an extended frame generates a frame having the same frame rate but higher resolution than the reference frame. For example, the extended frames 'S (n-4)', 'S (n-2)', 'S (n)', and 'S (n + 2)' shown in FIG. 4 are respectively basic frames 'B (n)'. -4) ',' B (n-2) ',' B (n) ', and' B (n + 2) ', but with higher resolution.

The extended frames forming such an extended layer are processed in an inter mode from a base frame of the base layer or an extended frame of itself (extended layer). Referring to FIG. 4, the extended frame 'S (n)' is referred to as the base frame 'B ( n) 'is used as a reference frame or an extended frame' S (n-4) 'or' S (n-2) 'previously located in time is used as the reference frame and processed in the inter mode.

As described above, the enhancement layer generated based on the base layer is linked to the base layer and is transmitted to the terminal through a second communication network that is different from the first communication network through which the basic frame information is transmitted. As in the case of temporal scalability, the second terminal 320 capable of reproducing high-definition broadcasting may select and reproduce a basic broadcast or a high-definition broadcast.

In the case of satellite DMB, the resolution and frame rate are set to QVGA (320 × 240) and 15fps, respectively, in the basic broadcasting, and VGA (640 × 480) / 15fps and XGA (1024 ×) are applied when the spatial scalability described above is applied. 768) / 15fps, SVGA (1280 × 1024) / 15fps, UXGA (1600 × 1200) / 15fps, etc., will be high quality broadcasts.

5 is a diagram illustrating a method of forming an enhancement layer using temporal and spatial scalability.

This is a combination of the above-described temporal scalability and spatial scalability, and forms a first enhancement layer using temporal scalability, and again forms a second enhancement layer using spatial scalability.

First, the basic layer formation process will be described, in which 'B (0)' is processed in the intra mode from the original image itself, and 'B (n)', the nth basic frame, is' B (n-4), which is the neighboring basic frame. ) ',' B (n-2) ', and' B (n + 2) 'and compare the continuity and similarity, then process them in the inter mode with reference to the most similar basic frame, or from the original image if the continuity and similarity are low It is processed in intra mode.

The first extended frame 'T (n + 1)' forming the first extended layer uses a neighboring basic frame 'B (n)' or 'B (n + 2)' as a reference frame or in time. The first extended frame 'T (n-3)' or 'T (n-1)', which is positioned previously, is used as the reference frame and processed in the inter mode. The first extended frames' T (n-3) ',' T (n-1) ', and' T (n + 1) 'respectively represent basic frames' B (n-4)' and 'B (n). -2) ', inserted after' B (n) 'to double the frame rate.

Finally, the second extended frame 'TS (n)' forming the second extended layer is processed in inter mode from the base frame 'B (n)' or from the first extended frame 'T (n + 1)'. The inter mode is processed or the second extended frame 'TS (n-2)' or 'TS (n-1)' is processed in the inter mode.

As described above, the first enhancement layer generated based on the base layer is linked with the base layer, and the second enhancement layer is again linked with the first enhancement layer. The basic frame information is transmitted to the terminal through the first communication network, and the first and second extended frame information are transmitted to the terminal through a different communication network from the first communication network. In this case, a method of transmitting the first extended frame information through the second communication network and transmitting the second extended frame information through another third communication network may also be considered.

Finally, the second terminal 320 capable of playing a high definition broadcast receives only basic frame information to play a basic broadcast, or receives basic frame information and first extended frame information to play a high quality broadcast having an improved frame rate, Alternatively, the display apparatus may receive high quality broadcast having improved resolution and frame rate by receiving both basic frame information and first and second extended frame information.

In the case of satellite DMB, the resolution and frame rate are set to QVGA (320 × 240) and 15fps, respectively, in the basic broadcasting, and VGA / 30fps, VGA / 60fps, and XGA / 30fps are applied when the temporal and spatial scalability described above is applied. For example, broadcasts such as XGA / 60fps will be high quality broadcasts.

On the other hand, the present invention may be combined with a known user (terminal) authentication technology for watching digital broadcasting, in particular, in the case of high-quality broadcasting, a service for authenticating a user (terminal) and charging an additional fee for this.

Although the present invention has been described in detail with reference to preferred embodiments, it will be apparent to those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. One embodiment is to be understood in all respects as illustrative and not restrictive.

In addition, the scope of the present invention is specified by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are included in the scope of the present invention. Should be interpreted as

According to the present invention, only basic frame information is transmitted to a professional digital broadcasting network, and extended frame information for high-definition broadcasting is transmitted through a conventional wireless internet, a wired internet, and a mobile communication network, thereby effectively using a limited radio resource (digital broadcasting channel). In addition, it has the effect of using both the terminals released in the past and new terminals for high-definition broadcasting.

Since the extended frame information for high definition broadcasting is linked with the basic frame information and includes only additional information for high definition broadcasting, the data capacity is reduced by the size of the basic frame information, thereby reducing network hatching. .

Claims (9)

A digital broadcasting center for classifying basic frame information capable of reproducing basic frames for basic broadcasting and extended frame information capable of reproducing high quality broadcast extended frames, respectively, and transmitting them to the first communication network and the second communication network; A first communication network transmitting the basic frame information; A second communication network transmitting the extended frame information and different from the first communication network; And A terminal configured to receive basic frame information through the first communication network, receive extended frame information through the second communication network, and output digital broadcasting by combining the basic frame information and the extended frame information; Digital broadcasting system using a heterogeneous network comprising a. The method of claim 1, And the first communication network is a satellite DMB network or a terrestrial DMB network. The method of claim 2, The second communication network is a digital broadcasting system using a heterogeneous network, characterized in that any one of the wireless Internet, wired Internet, mobile communication network. The method according to any one of claims 1 to 3, And the extended frame information uses temporal scalability, spatial scalability, or temporal and spatial scalability. The method according to any one of claims 1 to 3, The extended frame information includes first extended frame information using temporal scalability and second extended frame information using temporal and spatial scalability. The method of claim 5, The digital broadcasting system further includes a third communication network different from the first and second communication networks, wherein the first extended frame information is transmitted through a second communication network, and the second extended frame information is transmitted through a third communication network. Digital broadcasting system using a heterogeneous network, characterized in that the transmission. A digital broadcasting center classifying and transmitting basic frame information capable of reproducing a basic broadcast basic frame and extended frame information capable of reproducing a high quality broadcast extended frame, respectively; The basic frame information is transmitted through a first communication network, and the extended frame information is transmitted through a second communication network of a different type from the first communication network; Receiving, by the terminal, basic frame information through the first communication network and receiving extended frame information through the second communication network; And And outputting, by the terminal, the digital broadcast by combining the basic frame information and the extended frame information. The method of claim 7, wherein The basic frame information includes encoding mode information, reference frame identification information, and prediction error information for reproducing individual basic frames. The method according to claim 7 or 8, The extended frame information includes encoding mode information, reference frame identification information, and prediction error information for reproducing an individual extended frame.

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