KR101382613B1 - Method of multiplexing transmission frame, apparatus of multiplexing transmission frame and transmission apparatus for digital broadcasting signal - Google Patents

Abstract

In terrestrial DMB, a transmission device multiplexes a plurality of service streams generated for a given service into a plurality of ensemble. At this time, the same transmission time data is configured in the time stamp field of each transmission frame for each of the plurality of ensemble. In this way, a plurality of transmission devices send out a plurality of transmission frames including a service stream for the same service at the same time, so that the receiving device can receive the plurality of transmission frames at substantially the same time.

Terrestrial DMB, Ensemble, ETI, TIST, Timestamp, Frame Multiplexing

Description

Frame Multiplexing Method, Frame Multiplexing Device and Transmitting Device for Digital Broadcast Signal {METHOD OF MULTIPLEXING TRANSMISSION FRAME, APPARATUS OF MULTIPLEXING TRANSMISSION FRAME AND TRANSMISSION APPARATUS FOR DIGITAL BROADCASTING SIGNAL}

The present invention relates to a frame multiplexing method, a frame multiplexing apparatus and a transmission apparatus of a digital broadcast signal. In particular, the present invention relates to a frame multiplexing method, a frame multiplexing apparatus, and a digital multiplexing signal for transmitting a transmission frame of each of a plurality of ensembles including a service stream for the same service in a terrestrial digital multimedia broadcasting (DMB). It is about a transmitter.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Information and Communication and the Ministry of Information and Telecommunications Research and Development. .

Terrestrial digital multimedia broadcasting (DMB) is a multimedia service that provides CD-like stereo sound quality and video quality in mobile environments through the VERY HIGH FREQUENCY band with a bandwidth of about 1.5 MHz. .

In general, according to the terrestrial DMB system, a transmission device multiplexes a service stream for each of a plurality of different services into one ensemble, and generates a transmission frame in an ensemble unit. The transmission frame is modulated by a coded orthogonal frequency division multiplexing (COFDM) encoder and transmitted as a DMB broadcast signal.

On the other hand, when the transmitting apparatus transmits a plurality of transmission frames including a plurality of service streams generated for a certain service, the receiving apparatus must receive all of the plurality of transmission frames including the service stream of the corresponding service, and thus the corresponding service. Can be provided to the user. Accordingly, there is a problem that the receiving apparatus must include a high capacity buffer capable of storing a plurality of transmission frames, and it may take a long time for the receiving apparatus to decode a plurality of service streams multiplexed into the plurality of transmission frames.

The present invention has been made in an effort to provide a multiplexing method, a multiplexing apparatus, and a transmitting apparatus for transmitting a transmission frame for each of a plurality of ensemble including service streams for the same service at the same time.

According to a feature of the present invention for solving the above problems, the frame multiplexing apparatus includes a first buffer for storing a first service stream received from the outside, a second buffer for storing the second service stream received from the outside, the first buffer A time comparison processor for comparing first service time data for a first service stream with second service time data for the second service stream, and outputting a first frame including a first service stream output from the first buffer; A first frame generating unit, a second frame generating unit outputting a second frame including a second service stream output from the second buffer, and first transmission time data configured in a time stamp field of the first frame; And a time stamp generator for generating second transmission time data configured in the time stamp field of the second frame. Here, when the first service time data and the second service time data are the same, the time stamp generator generates the first transmission time data and the second transmission time data in the same manner.

The first transmission time data is used to determine a time point at which the first frame is transmitted, and the second transmission time data is used to determine a time point at which the second frame is transmitted.

If the first service time data and the second service time data are the same, the time comparison processor outputs the time point at which the first service stream is output from the first buffer and the second service stream from the second buffer. Match the time of day.

The frame multiplexing apparatus further comprises a satellite navigation device (GPS) receiver receiving a standard time from at least one satellite for generating the first transmission time data and the second transmission time data. And a first buffer output control unit for controlling the output of the first service stream and a second buffer output control unit for controlling the output of the second service stream according to the preceding and following of the first service time data and the second service time data. It further includes. The apparatus may further include a first time information extractor that recognizes the first service time data from the first service stream and a second time information extractor that recognizes the second service time data from the second service stream.

According to another aspect of the present invention, there is provided a frame multiplexing method comprising: storing a plurality of service streams including a first service stream and a second service stream from an external source in a buffer; Detecting service time data of each of the plurality of service streams; Comparing a plurality of service time data corresponding to each of the plurality of service streams with each other; Generating a first frame comprising the first service stream; Generating a second frame comprising the second service stream and first service time data corresponding to the first service stream stored in a first buffer and a second corresponding to the second service stream stored in a second buffer If the service time data are the same, generating the first transmission time data configured in the time stamp field of the first frame and the second transmission time data configured in the time stamp field of the second frame in the same manner.

The method may further include outputting the first service stream and the second service stream at the same time point if the first service time data and the second service time data are the same.

And a time at which the first service stream is maintained in the first buffer and a time at which the second service stream is maintained in the second buffer so that the first service stream and the second service stream are output at the same time. It further comprises the step of setting.

The method may further include generating the first frame and the second frame at the same time point if the first service time data and the second service time data are the same. In this case, the method may further include outputting a plurality of frames respectively corresponding to the plurality of service streams according to the plurality of service time data.

According to another aspect of the present invention, a transmitting apparatus receives a first frame from the outside and transmits the first frame according to first transmission time data configured in the time stamp field of the first frame. And a second transmitter configured to receive a second frame and transmit the second frame according to second transmission time data configured in the time stamp field of the second frame. Here, the first transmitter and the second transmitter are driven independently.

Here, when the first transmission time data and the second transmission time data are the same, a time point at which the first transmitter transmits the first frame and a time point at which the second transmitter transmits the second frame are the same. And a GPS receiver for receiving standard time from at least one satellite to recognize the first transmission time data and the second transmission time data.

In addition, the first transmitter and the second transmitter transmits a signal using the same modulation frequency. The first transmitter and the second transmitter transmit signals using different modulation frequencies.

According to the present invention, transmission synchronization of a plurality of transport frames including a service stream for the same service can be matched without configuring a separate field in the transport frame. Accordingly, a service having a capacity that cannot be multiplexed in one ensemble can be provided without having a large buffer in the receiving device and a relatively long time for decoding a plurality of service streams. have.

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. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

Now, a frame multiplexing method, a frame multiplexing apparatus, and a transmission apparatus of a digital broadcast signal according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The terrestrial DMB according to an embodiment of the present invention multiplexes each service stream for services such as video, audio, or data by ensemble, modulates and transmits a transmission frame of the ensemble.

1 is a view showing the configuration of a DMB transmission system according to an embodiment of the present invention.

As shown in FIG. 1, the DMB transmission system includes a video service encoder 110, an audio service encoder 120, a data service encoder 130, an ensemble multiplexer 200 (hereinafter referred to as an "ensemble multiplexer" or "frame multiplexer"). Device ", and a transmitter 300.

The video service encoder 110 provides a video service, the audio service encoder 120 provides a video service, and the data service encoder 130 provides a data service. The video service encoder 110, the audio service encoder 120, and the data service encoder 130 are operated by respective service providers, and convert each service into a service stream to convert each network. Transmission to the ensemble multiplexer 200 through.

 The ensemble multiplexing apparatus 200 is operated by an ensemble provider and receives a service stream transmitted through each network to generate an ensemble by multiplexing a service stream for each service. The transmission frame of the ensemble (hereinafter referred to as "transmission frame") is transmitted to the plurality of transmission apparatuses.

The transmitting device 300 is operated by a transmission network provider, modulates a transmission frame received from the ensemble multiplexing device 200 through a network in a coded orthogonal frequency division multiplexing (COFDM) scheme, and transmits it to each terminal. do. In this case, each of the transmitters 300 may transmit the transmission frame at the same time, and the transmission frame transmitted at the same time may be transmitted in a single frequency network (SFN) using the same modulation frequency or different. It may also be transmitted in a multiple frequency network using a modulation frequency.

2 is a diagram schematically illustrating a hierarchical structure of an ensemble transport interface (ETI) according to an embodiment of the present invention.

As shown in FIG. 2, the transmission frame, which is an output signal of the ensemble multiplexing apparatus 200, is a basic interface in a DMB transmission network.

The hierarchical structure of ETI is defined by three layers: a logical interface (LI) layer, a network independent (NI) layer, and a network adaptation (NA) layer.

The LI layer is the basic logical structure that defines the basic information for creating an ensemble. That is, the interface for configuring a service stream of services to be provided to the user such as audio, video or data in the field.

The NI layer is a simple physical interface layer that maps LIs and contains the basic interfaces of ETI-related devices. That is, it is an interface for allowing a frame generated in the LI layer to be properly transmitted to a transmitter in a relatively close distance transmitter or a transmission network in which there is no transmission error.

The NA layer is an error-protected physical interface layer that is mapped to the LI layer for use in an error-prone network environment compared to the NI layer. That is, when errors are prone to occur in the path to the transmitter due to a relatively long distance or a relatively large number of transmission errors, an interface for allowing a frame generated in the LI layer to be transmitted from the transmitter.

In addition, there are various types of interfaces such as ETI (NI, G.703), ETI (NI, V.11), and ETI (NA, G.704), depending on the type of interface signal used. 703 is used as the primary interface between the equipment transmitting the ensemble and is the standard input interface of the COFDM modulator.

FIG. 3 is a diagram illustrating a structure of a frame corresponding to a Logical Interface (LI) layer of an ensemble transport interface (ETI).

As shown in FIG. 3, a frame (hereinafter, referred to as a transmission frame) corresponding to the LI layer of the ETI is largely divided into a STAT (STATus) field and a LIDATA (Logical Interface DATA) field. The STAT field includes an ERR (ERRor status), and the LIDATA field includes an FC (Frame Characterization) field, an STC (Stream Characterization) field, an EOH (End Of Header) field. Field, MST (Main STream) field, EOF (End Of Frame) field, and TIST (TIme STamp) time stamp field.

The FC fields include FCT (Frame CounT), FICF (Fast Information Channel Flag) field, NST (Number of STream) field, FP (Frame Phase) frame. , MID (MODE) field and FL (Frame Length) field.

The STC field includes a plurality of Sub Stream Characterization (SSTC) fields, each SSTC field having a Sub Channel IDentification (SCID) field, a Start ADdress (SAD) field, and a Protection Level (TLP). Field, and STL (STream Length) field.

The EOH field includes a MNSC (Mux. Net. Sig. CH) field and a CRCh (Header CRC, Header Check) field.

The MST field includes a plurality of fast information channel (FIC) fields and a plurality of stream fields. In this case, each FIC field and stream field of the MST field are used to transmit a service stream applied from each service encoder. That is, the MST field is a field for configuring data to be broadcast.

The EOF field includes a CRC (Cyclic Redundancy Check) field and an Rfu (Reserved, Reserved) field.

The TIST field is composed of data (hereinafter, referred to as "transmission time data") for time when a corresponding transmission frame is transmitted by each transmitting apparatus, and constitutes a single frequency network (hereinafter referred to as "SFN"). Used for. Here, the transmission time data configured in the TIST field is determined in consideration of the time (hereinafter, referred to as "delay time") when the transmission frame is transmitted from the ensemble multiplexing apparatus 200 to each transmitting apparatus.

4 is a diagram schematically illustrating a digital multimedia broadcasting (DMB) system for constructing a single frequency network (SFN). A single frequency broadcasting network (SFN) refers to a network formed by a plurality of transmitters transmitting the same broadcast through the same frequency. That is, the plurality of transmitting devices transmits the same transmission frame to each receiving device at the same time using the same modulation frequency.

As illustrated in FIG. 4, the first transmitter 421 and the first frame R1, the second path R2, and the third path R3 generated by the ensemble multiplexer 410 respectively. It is transmitted to the second transmitter 422 and the third transmitter 433.

In this case, the time required for the transmission frame to reach the first transmission device 421 from the ensemble multiplexing device 410 through the first path R1 (hereinafter referred to as “first delay time”) and the second path The time required for the transmission frame to reach the second transmission device 422 through R2 (hereinafter referred to as a “second delay time”) and the third transmission device 423 through the third path R3. The time taken for the transmission frame to arrive in the following (hereinafter referred to as "third delay time") is different. However, the first transmission device 421, the second transmission device 422, and the third transmission device 423 may provide the appropriate broadcast only when the same transmission frame is transmitted at the same time. Accordingly, the transmission time point of the transmission frame is determined in consideration of the first delay time, the second delay time, and the third delay time, and data on the transmission time point of the transmission frame determined as described above (hereinafter, referred to as "transmission time data"). ) Is stored in the TIST field of the transport frame.

Each transmission device 421, 422, 423 transmits the transmission frame at a time determined from transmission time data configured in the TIST field of the transmission frame when the transmission frame arrives from the ensemble multiplexer 410. Accordingly, the same transmission frame can be sent by the plurality of transmission apparatuses at the same time according to the frame transmission time data.

Meanwhile, the ensemble multiplexing apparatus 410 generates a plurality of service streams for a service and multiplexes the plurality of service streams into different transmission frames, respectively, for a service that cannot be multiplexed with one ensemble. At this time, if the receiving device receives a plurality of transmission frames including a service stream for the same service at a relatively same time, the receiving device may reduce the burden for receiving the plurality of transmission frames.

Hereinafter, a frame multiplexing method and a frame multiplexing apparatus of a terrestrial DMB system for transmitting two or more transmission frames at the same time will be described.

5 is a flowchart illustrating a frame multiplexing method according to an embodiment of the present invention.

As shown in FIG. 5, the ensemble multiplexing apparatus 410 first receives a plurality of service streams for each service from each network (S510). Each of the plurality of service streams is stored in a buffer.

The ensemble multiplexing device 410 extracts time information (shown as "service time data" in FIG. 5 and hereinafter referred to as "service time data") included in each service stream, for the plurality of service streams thus received. (S520). In this case, the service time data may be set to a time at which a corresponding service stream is to be serviced at each receiver or to a time at which a service stream is generated.

The ensemble multiplexer 410 searches for the same service time data by comparing the service time data of each service stream with each other (S530). For the sake of brevity, hereinafter, it is assumed that a first service stream and a second service stream having the same service time data and that cannot be multiplexed into one ensemble are found.

In addition, the ensemble multiplexing apparatus 410 may include a first transport frame including the first service stream and a second service stream for each of the first service stream and the second service stream having the same service time data. 2 transmission frames are generated (S540). In this case, the output of the first service stream and the output of the second service stream may be performed at the same time to simultaneously generate a first transport frame including the first service stream and a second transport frame including the second service stream. have.

The ensemble multiplexer 410 considers each delay time generated between the ensemble multiplexer 410 and the plurality of transmitters 421, 422, and 423, and transmits time data (hereinafter, &Quot; first transmission time data ") and configure the first transmission time data in the TIST field of the first transmission frame. Then, in consideration of each delay time, outgoing time data (hereinafter referred to as "second outgoing time data") of the second transmission frame is generated, and the second outgoing time data is configured in the TIST field of the second transport frame. . In this case, since the first transmission frame and the second transmission frame each include service streams having the same service time data, the first transmission time data and the second transmission time data are set identically (S550).

The transmitting apparatus receives a plurality of transmission frames from the ensemble multiplexer and extracts transmission time data configured in the TIST field of each of the plurality of transmission frames. The plurality of transmission frames are sequentially transmitted according to the transmission time data of each transmission frame. At this time, the transmitting device transmits the first transmission frame and the second transmission frame having the same transmission time data at the same time (S560).

Hereinafter, a frame multiplexing apparatus that configures the same transmission time data in each TIST field of two or more transport frames including different service streams for the same service will be described.

The apparatus for frame multiplexing according to an embodiment of the present invention includes a plurality of buffers for temporarily storing a plurality of service streams received through respective networks, and a plurality of extracting service time data from individual service streams stored in each buffer. And a plurality of frame generators for generating a transmission frame including at least one service stream output from each buffer according to the time information extractor and the service time data. Here, the plurality of frame generators independently generate the transmission frames.

6 is a block diagram of a frame multiplexing apparatus according to an embodiment of the present invention. In FIG. 6, only a frame multiplexing apparatus including two buffers, two time information extractors for extracting service time data of each service stream stored in each buffer, and two frame generators are illustrated.

Frame multiplexing apparatus according to an embodiment of the present invention, the first buffer 611, the second buffer 612, the first time information extractor 621, the second time information extractor 622, the time comparison processor ( 630, a first buffer output controller 641, a second buffer output controller 642, a first frame generator 651, a second frame generator 652, a time stamp (TIST) generator 660, and GPS receiver 670 is included.

The first buffer 611 temporarily stores the first service stream S610 received through the network, and the second buffer 612 stores the second service stream S620 received through the network. Temporarily save. In this case, it is assumed that the first service stream S610 and the second service stream S620 are multiplexed on different ensembles.

The first time information extractor 621 outputs service time data (hereinafter, referred to as “first service time data”) of the first service stream S610 stored in the first buffer 611, and second time information. The extractor 622 outputs service time data (hereinafter referred to as "second service time data") of the second service stream S620 stored in the second buffer 612. In this case, the first time information extracting unit 621 and the second time information extracting unit 622 may store the first service time data and the second service time based on the same position of the first buffer 611 and the second buffer 621. Extract the data.

The time comparison processor 630 compares the first service time data with the second service time data. At this time, the time comparison processing unit 630 determines the time at which the first service stream and the second service stream are output from each buffer according to the first and second service time data and the second service time data.

That is, when the first service time data is earlier than the second service time data, the first service stream S610 from the first buffer 611 than the second service stream S620 is output from the second buffer 612. ) Will be executed first. That is, the time comparison processing unit 630 may be configured to temporarily store the first service stream S610 in the first buffer 611 so that the first service stream S610 is output before the second service stream S620. (Hereinafter, referred to as "first buffer output delay time") and a time for which the second service stream S620 is temporarily stored in the second buffer 612 (hereinafter referred to as "second buffer output delay time") are respectively set. .

On the other hand, when the second service time data is earlier than the first service time data, the time comparison processor 630 may output the second buffer 612 rather than outputting the first service stream S610 from the first buffer 611. Outputting the second service stream (S620) from the first) is performed first. That is, the time comparison processing unit 630 sets the first buffer output delay time and the second buffer output delay time, respectively, so that the second service stream S620 is output before the first service stream S610.

On the other hand, the time comparison processing unit 630 outputs the first service stream S610 from the first buffer 611 and the second buffer 612 if the first service time data and the second service time data are the same. The first buffer output delay time and the second buffer output delay time are respectively set so that outputting the second service stream S620 is performed at the same time.

The first buffer output controller 641 controls to output the first service stream S610 from the first buffer 611 according to the first buffer output delay time. The second buffer output controller 642 controls to output the second service stream S620 from the second buffer 612 according to the second buffer output delay time. In this case, the first buffer output control unit 641 and the second buffer output control unit 642 are driven independently, so that the time point at which the first service stream S610 is output and the time point at which the second service stream S620 is output are the same. It can be different or different.

The first frame generation unit 651 generates a first transmission frame including the first service stream S610 output from the first buffer 611 under the control of the first buffer output control unit 641, thereby generating a network ( network). In addition, the second frame generation unit 652 generates a second transmission frame including the second service stream S610 output from the second buffer 612 under the control of the second buffer output control unit 642, thereby generating a network. Print as (network). In this case, the first frame generator 651 and the second frame generator 652 are driven independently of each other.

Meanwhile, the time stamp generator 660 generates first transmission time data and second transmission time data using a standard time. The first transmission time data generated as described above is applied to the first frame generation unit 651 and configured in the TIST field of the first transmission frame. The second transmission time data is applied to the second frame generation unit 652 and configured in the TIST field of the second transmission frame. Here, the first transmission time data and the second transmission time data are generated in consideration of the time (delay time) when the transmission frame is transmitted from the ensemble multiplexing device to each transmitting device.

In addition, as shown in FIG. 6, the standard time can be obtained from a GPS (Global Positioning System) receiver 570 which obtains information on accurate time from at least three satellites. Although FIG. 6 illustrates that a reference time is obtained using a GPS receiver, the embodiment of the present invention is not limited thereto, and any method of obtaining the reference time may be applied to the present invention.

As described above, according to the frame multiplexing apparatus according to the embodiment of the present invention, in a plurality of transport frames each including a plurality of service streams for a given service, the same transmission time data is included in each TIST field of the plurality of transport frames. Configure The transmitting apparatus checks the frame transmission time data configured in the TIST field of the transmission frame received from the ensemble multiplexing device and transmits the corresponding transmission frame, and two or more transmission frames having the same frame transmission time data are transmitted together at the corresponding time. .

Hereinafter, a description will be given of a transmission apparatus capable of simultaneously transmitting two or more transmission frames. The transmitter according to the embodiment of the present invention includes a plurality of RF signal transmitters.

7 is a diagram illustrating a transmitter according to an embodiment of the present invention. FIG. 7 illustrates a frame synchronous transmitter including only two RF transmitters for receiving two different transmission frames. Here, "RF" means radio frequency.

As shown in FIG. 7, the frame synchronization transmitter includes a first RF signal transmitter 711, a second RF signal transmitter 712, and a GPS receiver 720.

The first RF signal transmitter 711 and the second RF signal transmitter 712 individually receive different transmission frames, and determine a transmission time of the corresponding transmission frame by checking the TIST field of the received transmission frame.

The GPS receiver 720 is used to obtain a reference time for recognizing frame transmission time data configured in the TIST field of the received transmission frame.

The operation of the frame synchronous transmission device shown in FIG. 7 can be explained with the following example. That is, the first RF transmitter 711 receives the first transmission frame transmitted by the ensemble multiplexer illustrated in FIG. 6, and recognizes the first transmission frame using the TIST field of the first transmission frame and the reference time obtained by the GPS receiver 720. The first transmission frame is transmitted according to one frame transmission time data. The second RF transmitter 712 receives the second transmission frame transmitted by the ensemble multiplexer, and applies the frame transmission time data recognized using the TIST field of the second transmission frame and the reference time obtained by the GPS receiver 720. Accordingly, the second transmission frame is transmitted.

In this case, when the same frame transmission time data is configured in the TIST field of the first transmission frame and the TIST field of the second transmission frame, the first RF transmitter 711 and the second RF transmitter 712 are configured at the same time. The 1st transmission frame and the 2nd transmission frame are transmitted, respectively.

Meanwhile, the first RF signal transmitter 711 and the second RF signal transmitter 712 may transmit the terrestrial DMB signal using the same modulation frequency to configure the SFN. Alternatively, since the first RF signal transmitter 711 and the second RF signal transmitter 712 are driven independently, it is also possible to transmit a terrestrial DMB signal using different modulation frequencies. Alternatively, although not shown in FIG. 7, the first RF signal transmitter 711 and the second RF signal transmitter 712 are included in an RF signal transmitter (not shown), and the RF signal transmitter (not shown) is hierarchically modulated (LAYERED). By using a transmission method such as MODULATION, it is also possible to transmit a signal having the same TIST field value among the signals having the RF of the same frequency band at the same time.

As described above, according to an exemplary embodiment of the present invention, a plurality of transport frames each including a plurality of service streams for a given service are not configured in order to transmit two or more transport frames at the same time. Can send at the same time. Accordingly, since the receiving apparatus can receive a plurality of transmission frames including service streams for the same service at about the same time, it is not necessary to have a large buffer and takes a long time for decoding the service. There is no need to do it.

The embodiments of the present invention described above are not only implemented by the apparatus and method but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded, The embodiments can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

1 is a view showing the configuration of a DMB transmission system according to an embodiment of the present invention.

2 is a diagram schematically illustrating a hierarchical structure of an ensemble transport interface (ETI) according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a structure of a frame corresponding to a Logical Interface (LI) layer of an ensemble transport interface (ETI).

4 is a diagram schematically illustrating a digital multimedia broadcasting (DMB) system for constructing a single frequency network (SFN).

5 is a flowchart illustrating a frame multiplexing method according to an embodiment of the present invention.

6 is a block diagram of a frame multiplexing apparatus according to an embodiment of the present invention.

7 is a diagram illustrating an apparatus for transmitting frame synchronization according to an embodiment of the present invention.

Claims (16)

A first buffer for storing a first service stream received from the outside; A second buffer for storing a second service stream received from the outside; A time comparison processing unit for comparing first service time data for the first service stream with second service time data for the second service stream; A first frame generator for outputting a first frame including a first service stream output from the first buffer; A second frame generator for outputting a second frame including a second service stream output from the second buffer; A time stamp generator for generating first transmission time data configured in the time stamp field of the first frame and second transmission time data configured in the time stamp field of the second frame; The time stamp generator, And when the first service time data and the second service time data are the same, generate the first transmission time data and the second transmission time data in the same manner. The method according to claim 1, And the first transmission time data is used to determine when to send the first frame, and the second transmission time data is used to determine when to send the second frame. The method according to claim 1, The time comparison processing unit, If the first service time data and the second service time data are the same, And a time point at which the first service stream is output from the first buffer and a time point at which the second service stream is output from the second buffer. The method according to claim 1, And a satellite navigation device (GPS) receiver receiving a standard time from at least one satellite for generating the first transmission time data and the second transmission time data. The method according to claim 1, According to the preceding and following of the first service time data and the second service time data, A first buffer output control unit controlling an output of the first service stream; And a second buffer output control unit controlling the output of the second service stream. The method according to claim 1, A first time information extractor configured to recognize the first service time data from the first service stream; And a second time information extractor configured to recognize the second service time data from the second service stream. Storing a plurality of service streams including a first service stream and a second service stream from an external source in each buffer; Detecting service time data of each of the plurality of service streams; Comparing a plurality of service time data corresponding to each of the plurality of service streams with each other; Generating a first frame comprising the first service stream; Generating a second frame comprising the second service stream; And If the first service time data corresponding to the first service stream stored in the first buffer and the second service time data corresponding to the second service stream stored in the second buffer are the same, a time stamp field of the first frame is included. And generating identically the first transmission time data configured and the second transmission time data configured in the time stamp field of the second frame. 8. The method of claim 7, If the first service time data and the second service time data are the same, And outputting the first service stream and the second service stream at the same time. 9. The method of claim 8, So that the first service stream and the second service stream are output at the same time, And setting a time at which the first service stream is maintained in the first buffer and a time at which the second service stream is maintained in the second buffer, respectively. 8. The method of claim 7, If the first service time data and the second service time data are the same, Generating the first frame and the second frame at the same time. 10. The method of claim 9, And outputting a plurality of frames respectively corresponding to the plurality of service streams according to the plurality of service time data. A first transmitter which receives a first frame from the outside and transmits the first frame according to first transmission time data configured in the time stamp field of the first frame; A second transmitter which receives a second frame from the outside and transmits the second frame according to second transmission time data configured in the time stamp field of the second frame; The first transmitter and the second transmitter are driven independently, If the first sending time data and the second sending time data is the same, And a time point at which the first transmitter transmits the first frame and a time point at which the second transmitter transmits the second frame are the same. delete 13. The method of claim 12, And a GPS receiver for receiving standard time from at least one satellite to recognize the first transmission time data and the second transmission time data. 13. The method of claim 12, And the first transmitter and the second transmitter transmit a signal using the same modulation frequency. 13. The method of claim 12, And the first transmitter and the second transmitter transmit a signal using different modulation frequencies.

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