KR101976628B1 - Method for channel switching and channel reception, and apparatus for channel switching and channel reception - Google Patents

Abstract

A channel switching method and a channel receiving method for enhancing spectral efficiency, and a channel switching apparatus and a channel receiving apparatus using the method are disclosed. The channel switching method includes the steps of extracting broadcast data for a corresponding virtual channel existing in a physical channel using information of a currently viewed virtual channel of a user, determining an idle frequency band in the physical channel in which the extracted broadcast data exists, Determining a communication data to be added to the physical channel, and transmitting a transmission data stream generated using broadcast data and communication data included in the physical channel, wherein the physical channel uses a constant frequency band, And may include broadcast data for a virtual channel.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel switching method and a channel receiving method for improving spectral efficiency and a channel switching apparatus and a channel receiving apparatus using the method,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel switching method and a channel receiving method for increasing spectral efficiency, a channel switching apparatus and a channel receiving apparatus using the method, and more particularly, To a channel switching method and a channel receiving method in which resources of a channel that is not transmitted are allocated for cable communication.

In the past, the broadcasting network simply provided a unidirectional service for transmitting broadcast signals. However, the cable broadcasting network not only transmits broadcasting signals to users, but also can provide interactive services such as Internet and VoIP using a cable modem. In particular, the recent digital broadcasting network is capable of providing a multi-channel broadcasting service and a broadband internet service with a broadband access network. However, in spite of having broadband frequency resources, frequency resources already available have come to the limit due to the provision of high-capacity broadcasting services such as UHDTV and the demand for faster data communication services.

The cable layout may vary slightly for each cable operator. However, in most cable networks, the 5 to 42 MHz band is used for upstream transmission and the 54 to 864 MHz or 1,002 MHz band is used for downstream transmission. The down stream may be divided into analog broadcasting data, digital broadcasting data, and communication data transmission, each of which is transmitted using channels of 6 MHz units.

In digital broadcasting, channel switching technology means not only transmitting broadcast channels unilaterally but transmitting channels selected by users. That is, it is possible to increase the frequency use efficiency by using the idle channel band, which is transmitted only by the channels selected by the users, as other use (for example, communication service). Generally, in the broadcast channel transmission, both the currently viewed channels and the non-viewed channels are transmitted to the user, and the user views the selected channel among the transmitted channels. Transmitting all of the broadcast data that is not viewed has tremendous inefficiency in terms of frequency usage. However, unlike telecommunication, broadcasting considers uni-directional transmission, so this inefficiency should be considered.

The present invention relates to a channel switching method and a channel receiving method for enhancing spectral efficiency, a channel switching apparatus and a channel receiving apparatus using the method, and in order to overcome the disadvantage, a broadcasting channel currently being watched is selectively transmitted And a channel switching method and a channel receiving method for allocating resources of other non-transmitted channels for cable communication.

A channel transmission method performed by a channel transmission device, the channel transmission method comprising: extracting broadcast data for a corresponding virtual channel existing in a physical channel using information of a currently viewed virtual channel of a user; Comprising the steps of: determining communication data to be added to an idle frequency band in the physical channel in which broadcast data exists; and transmitting a transmission data stream generated using broadcast data and communication data included in the physical channel, The physical channel uses a constant frequency band and can include broadcast data for a plurality of virtual channels.

Broadcast data and communication data included in the physical channel may be transmitted in the form of a data packet.

Further comprising the step of generating identification information of broadcast data corresponding to the virtual channel information using the virtual channel information currently being viewed by the user, wherein the extracting step comprises: The broadcast data matching the identification information among the broadcast data existing in the physical channel can be filtered.

The PID (Packet ID) information of the broadcast data may be used as the identification information of the broadcast data.

The determining may comprise identifying an idle frequency band in the physical channel and selecting communication data to be added to the identified idle frequency band.

Wherein the determining step comprises: decreasing communication data added to the idle frequency band in the physical channel as the broadcast data to be transmitted in the physical channel is increased, and adding to the idle frequency band in the physical channel as the broadcast data to be transmitted in the physical channel decreases It is possible to increase the communication data.

The determining step may consider broadcast data as priority if broadcast data and communication data can be equally added to the idle frequency band in the physical channel.

In the channel receiving method performed by the channel receiving apparatus, the channel receiving method may include receiving switching information of a virtual channel to be viewed by the user, and transmitting the switching information of the received virtual channel to the channel switching apparatus have.

A channel receiving method performed by a channel receiving apparatus, the channel receiving method comprising: receiving a transmission data stream generated using broadcast data and communication data included in a physical channel; and transmitting the communication data included in the received transmission data stream And extracting the extracted data.

The extracting may use PID (Packet ID) information of the communication data.

The channel switching device includes an extraction unit for extracting broadcast data for a corresponding virtual channel existing in a physical channel by using information of a currently viewed virtual channel of a received user, A determination unit for determining communication data to be added to a band, and a transmission unit for transmitting a transmission data stream generated using broadcast data and communication data included in the physical channel, wherein the physical channel uses a constant frequency band, And may include broadcast data for a plurality of virtual channels.

Broadcast data and communication data included in the physical channel may be transmitted in the form of a data packet.

Further comprising a generation unit configured to generate identification information of broadcast data corresponding to the virtual channel information by using the virtual channel information currently being viewed by the user, wherein the extraction unit extracts, The broadcast data matching the identification information among the broadcast data existing in the physical channel can be filtered.

The PID (Packet ID) information of the broadcast data may be used as the identification information of the broadcast data.

The determination unit may identify an idle frequency band in the physical channel and select communication data to be added to the identified idle frequency band.

Wherein the determining unit decreases the communication data added to the idle frequency band in the physical channel as the broadcast data to be transmitted in the physical channel increases and transmits the communication data added to the idle frequency band in the physical channel as the broadcast data to be transmitted in the physical channel decreases Data can be increased.

If the broadcast data and the communication data can be equally added to the idle frequency band in the physical channel, the determination unit may consider the broadcast data as priority.

The channel receiving apparatus may include a receiving unit for receiving switching information of a virtual channel to be viewed by the user and a transmitting unit for transmitting the switching information of the received virtual channel to the channel switching device.

The channel receiving apparatus may include a receiver for receiving a transmission data stream generated by using broadcasting data and communication data included in a physical channel, and an extracting unit for extracting communication data included in the received transmission data stream.

The extraction unit may use PID (Packet ID) information of the communication data.

According to an embodiment of the present invention, the efficiency of using frequency resources can be increased by selectively transmitting broadcast channels currently being watched and allocating resources of other channels that are not transmitted for cable communication.

According to an embodiment of the present invention, efficiency of use of frequency resources can be increased in a cost-effective manner without building a complicated system.

FIG. 1 illustrates a channel switching method performed in a general digital cable broadcasting according to an exemplary embodiment of the present invention.
FIG. 2 illustrates a channel switching method according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 3 illustrates a channel switching device according to an embodiment.
FIG. 4 illustrates a channel switching method according to an embodiment.
FIG. 5 illustrates a channel receiver (set-top box) according to an embodiment.
FIG. 6 illustrates a channel receiving apparatus (cable modem) according to an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 illustrates a channel switching method performed in a general digital cable broadcasting according to an exemplary embodiment of the present invention.

Digital cable broadcasting can be divided into broadcasting channel and communication channel. At this time, a physical 6 MHz band in each broadcast channel and a communication channel is called a physical channel, and broadcast data for a plurality of virtual channels may exist in the physical channel. Here, the virtual channel refers to a channel viewed by users in a digital cable broadcasting. In the example of FIG. 1 (a), it is assumed that six virtual channels are multiplexed and transmitted within a 6-MHz physical channel. A general digital cable broadcasting transmits all broadcasting data existing in a physical channel of a broadcasting channel. That is, in the case of FIG. 1, broadcast data about virtual channels viewed by users as well as broadcast data about virtual channels not viewed by users are transmitted together.

1 (b) shows a virtual channel currently being watched among a plurality of virtual channels existing in a physical channel. It can be seen that there are not many virtual channels currently being watched among the virtual channels existing in the physical channel. In the present invention, an idle frequency band in a physical channel corresponding to a virtual channel not currently watched by current users is allocated for cable communication, thereby efficiently using frequency resources.

1C shows an example in which users are re-multiplexed with the virtual channels currently being watched in FIG. 1B to fill in the physical channels from the front, and use physical channels in the remaining broadcast channels as communication channels for cable communication Lt; / RTI > That is, efficient use of frequency resources is provided through channel switching. Accordingly, in FIG. 1, a broadcast channel for a broadcast service is reduced, and a communication channel for a communication service is increased.

The channel switching method of FIG. 1 can use frequency resources most efficiently. However, the channel switching method shown in FIG. 1 has disadvantages in implementation of channel switching system and channel operation. The channel switching system performing the channel switching method must perform re-multiplexing of the virtual channel in real time every time the virtual channel being viewed by the user is switched. To this end, the channel switching system must include a remultiplexer for each physical channel, and broadcast data of a virtual channel input to each physical channel must be constantly changed to broadcast data of virtual channels viewed by the current user.

Accordingly, the channel switching system must include a routing device for inputting broadcast data of a virtual channel to a virtual channel of the corresponding physical channel. In addition, a PAT (Program Association Table) which is signaling information (e.g., physical channel frequency information, a program number in a physical channel) for the virtual channels and program specific information (PSI) Map Table) and CAT (Conditional Access Table) data must be updated in real time as the virtual channel in the physical channel is changed. Therefore, in order to support the channel switching method performed by the channel switching system of FIG. 1, it is required to construct a complicated system, which requires a large cost.

FIG. 2 illustrates a channel switching method according to an exemplary embodiment of the present invention. Referring to FIG.

In the conventional channel switching system, broadcasting and communication services use physical channels of different frequency bands. However, the present invention proposes a method in which a broadcasting service and a communication service share the same frequency. In addition, in the conventional general channel switching system, the virtual channel has to be remultiplexed in real time according to the virtual channel information currently being watched by the user.

However, in the present invention, among broadcast data existing in a physical channel, broadcast data for a virtual channel not viewed by a user may not be transmitted. The present invention also provides a method of adding communication data to an idle frequency band of each physical channel to which broadcast data is not transmitted and transmitting the communication data. When using the above method, it is not necessary to re-multiplex physical channels to be transmitted after switching broadcast data for a virtual channel as shown in FIG. In addition, since no re-multiplexing is performed on the physical channels, there is no physical channel change of the virtual channels, and no channel signaling information is required.

That is, the same frequency utilization efficiency as that of FIG. 1 is obtained through the apparatus for extracting broadcasting data for a corresponding virtual channel by using the virtual channel information currently being watched by the user and determining communication data to be added to the idle frequency band in the physical channel . Therefore, in the case of FIG. 2, the communication service is increased without increasing or decreasing the communication channel for broadcasting service or communication service for broadcasting service.

In this case, as shown in FIG. 2, it is possible that the broadcast service and the communication service can use the same physical channel because the DOCSIS 3.0 specification defines transmission of data by combining channels. That is, in the DOCSIS 3.0 standard, it is possible to distribute data on a plurality of physical channels in transmission of data on the transmission side, and to combine and receive data transmitted on a plurality of channels dispersed on the reception side.

FIG. 3 illustrates a channel switching device according to an embodiment.

The channel transmission apparatus 300 may include a generating unit 310, an extracting unit 320, a determining unit 330, and a transmitting unit 340. The generating unit 310 may acquire information on a virtual channel currently being watched by the user. The information on the virtual channel acquired by the generating unit 310 may be received in real time whenever the virtual channel to be viewed by the user is switched.

The generating unit 310 may generate filtering information for identifying broadcast data of a virtual channel currently being viewed by the user using information on the currently viewed virtual channel of the user. At this time, the generated filtering information may be the packet ID (PID) value of the broadcast data of the virtual channel currently viewed by the user.

In digital cable broadcasting, broadcasting service and communication service use the same physical layer transmission protocol. The physical layer transmission is a process of modulating broadcast data and communication data by QAM (Quadrature Amplitude Modulation) to generate an RF signal of 6 MHz band and transmitting it to a digital cable broadcasting network. Here, an MPEG-2 TS (Transport Stream) is used as an input data format of the QAM modulator. An MPEG-2 TS is a sequence of MPEG-2 TS packets consisting of 188 bytes, and an MPEG-2 TS packet is composed of a 4-byte packet header and a payload of 184 bytes.

In general, broadcast data is transmitted through an MPEG-2 TS packet and broadcast data (video, audio, data, etc.) stored in the packet can be identified through a Packet ID (PID) value existing in the packet header. The communication data is also converted into MPEG-2 TS packets. Here, the value 0x1FFE fixed to the packet ID (PID) value of the packet is used to indicate that the MPEG-2 TS packet carries the communication data.

Accordingly, the generating unit 310 may use the Packet ID (PID) value of the packet in generating the filtering information for extracting the broadcast data for the virtual channel currently viewed by the user from the broadcast data existing in the physical channel .

The extracting unit 320 may extract broadcast data for a virtual channel that the user is currently viewing among broadcast data existing in the physical channel. At this time, the extracting unit 320 may use the filtering information generated by the generating unit 310 to extract broadcast data of a virtual channel currently viewed by the user. The extracting unit 320 may extract broadcast data having a packet ID (PID) value that matches the corresponding packet ID (PID) value using the filtering information, and may transmit the extracted broadcast data to the transmission data buffer.

The determination unit 330 can identify the idle frequency band in the physical channel and select the communication data to be added to the identified idle frequency band. The idle frequency band in the physical channel can be confirmed through broadcast data existing in the transmission data buffer. In the transmission data buffer, broadcast data for a virtual channel currently being viewed by the user exists. Accordingly, the determination unit 330 can determine the amount of data to be added to the identified idle frequency band by checking the amount of broadcast data existing in the transmission data buffer.

That is, as the number of broadcast data to be transmitted in the physical channel increases, the number of communication data added to the idle frequency band in the physical channel decreases. Also, as the number of broadcast data to be transmitted in the physical channel decreases, the determining unit 330 may increase the communication data added to the idle frequency band in the physical channel.

At this time, when it is possible to equally add broadcast data and communication data to the idle frequency band in the physical channel, the decision unit 330 can consider the broadcast data as priority. That is, when there is an idle frequency band in the physical channel, and the broadcast data is additionally requested according to the channel change of the user, the determining unit 330 may add the broadcast data first and add the communication data to the remaining idle frequency band.

The transmitter 340 may transmit the broadcast data for the virtual channel currently viewed by the user and the communication data added to the idle frequency band in the physical channel. The transmitter 340 may transmit a transmission data stream including broadcast data and communication data in the physical channel to be transmitted by using a quadrature amplitude modulation (QAM) modulation method.

FIG. 4 illustrates a channel switching method according to an embodiment.

In step 410, the channel switching device 300 may receive information on a virtual channel currently viewed from a user. At this time, the information about the virtual channel received from the user can be received in real time whenever the user switches the virtual channel to be viewed.

In operation 420, the channel switching device 300 may generate filtering information for identifying broadcast data of a virtual channel currently viewed by the user using the received information. At this time, the generated filtering information may be the packet ID (PID) value of the broadcast data of the virtual channel currently viewed by the user.

This is because information on channels transmitted and received in the digital cable broadcasting is transmitted in the form of packets. At this time, a Packet ID (PID) for the broadcast data may exist in the packet header. In particular, in the case of communication data, a value 0x1FFE fixed to the packet ID (PID) value of the packet can be used to indicate that the packet includes the communication data.

In step 430, the channel switching device 300 extracts broadcast data for a virtual channel that the user is currently viewing, among broadcast data existing in each physical channel, using the filtering information generated in step 420 . That is, the channel switching device 300 can extract the broadcast data existing in the physical channel using the Packet ID (PID), which is filtering information generated using the broadcast data for the virtual channel currently viewed by the user.

The extracted broadcast data can be moved to the transmission data buffer via the MUX. That is, the transmission data buffer includes broadcast data for a virtual channel that the user is currently viewing, among broadcast data in a physical channel.

In step 440, the channel switching device 300 may determine communication data that may be added to the idle frequency band in the physical channel. At this time, the communication data that can be added to the idle frequency band in the physical channel can be determined by broadcasting data existing in the transmission data buffer. For example, suppose that the current user views the first virtual channel and the second virtual channel is not being watched. The channel switching device 300 may filter the broadcast data for the virtual channel 1 and move to the transmission data buffer through the MUX. However, the broadcast data for the second virtual channel can not be filtered and moved to the transmission data buffer. Accordingly, the channel switching device 300 can select communication data that can be added to the idle frequency band in the physical channel by the amount of broadcast data for the second virtual channel that the user does not currently watch.

At this time, as the number of broadcast data to be transmitted in the physical channel increases, the channel switching device 300 can reduce the communication data added to the idle frequency band in the physical channel. Also, as the broadcast data to be transmitted in the physical channel is reduced, the channel switching device 300 can increase the communication data added to the idle frequency band in the physical channel.

In step 450, the channel switching device 300 may multiplex the broadcasting data and the communication data existing in the physical channel to form a transmission data stream in which broadcast data and communication data are mixed.

At this time, if it is possible to add the broadcast data and the communication data to the idle frequency band in the physical channel equally, the channel switching device 300 can consider the broadcast data as priority. That is, when there is an idle frequency band in the physical channel and the broadcast data is further requested according to the channel change of the user, the channel switching device 300 may add the broadcast data first and add the communication data to the remaining idle frequency band .

In step 460, the channel switching device 300 may QAM-modulate the transmission data stream generated in step 450 and finally output it in the form of an RF signal.

FIG. 5 illustrates a channel receiver (set-top box) according to an embodiment.

The channel receiving apparatus (set top box) 500 may include a receiving unit 510 and a transmitting unit 520. The channel receiver (set-top box) 500 may receive and RF-demodulate the RF signal transmitted from the channel switching device 300 and then decode the broadcast data for the virtual channel selected by the user in the QAM demodulation output. Thereafter, the user can view the decoded broadcast data.

The transmitter 520 may transmit channel switching information that the user views to the channel switching device 300. The transmitting unit 520 transmits the switching information of the channel viewed by the user to the channel switching device 300 in real time so that the channel switching device 300 can extract broadcasting data for the virtual channel to be transmitted.

FIG. 6 illustrates a channel receiving apparatus (cable modem) according to an embodiment.

The channel receiving apparatus (cable modem 600) may include a receiving unit 610 and an extracting unit 620. The receiving unit 610 may receive the RF signal transmitted from the channel switching device 300 and perform QAM demodulation. At this time, broadcast data and communication data may be mixed in the demodulated RF signal. In the conventional case, the communication data is received by an independent physical channel, and no separate packet filtering is required. However, in the present invention, broadcast data and communication data may exist together in the same physical channel. Therefore, the channel receiving apparatus (cable modem 600) needs to extract the communication data from the demodulated RF signal.

The extractor 620 can extract the communication data from the demodulated RF signal. In general, a cable modem is implemented to receive only packets of communication data, that is, MPEG-2 TS packets carrying DOCSIS MAC frames. The Packet ID (PID) of the MPEG-2 TS packet including the DOCSIS MAC frame is fixed at 0x1FFE. Accordingly, the extracting unit 620 can identify the communication data in the demodulated RF signal by extracting the packet having the packet ID (PID) of 0x1FFE. Therefore, even when broadcast data and communication data are mixed in the received signal, the communication service can be performed without any problem.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA) A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

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. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced. Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

300: Channel switching device
310:
320:
330:
340:
500: Channel receiving apparatus (set-top box)
510: Receiver
520:
600: Channel receiving device (cable modem)
610:
620:

Claims (20)

Generating identification information of broadcast data corresponding to the virtual channel information using the virtual channel information currently being watched by the user
Extracting broadcast data for a corresponding virtual channel existing in a physical channel using information of a currently viewed virtual channel of a user;
Determining communication data to be added to an idle frequency band in the physical channel in which the extracted broadcast data exists; And
Transmitting a transmission data stream generated using broadcast data and communication data included in the physical channel
Lt; / RTI >
The physical channel includes:
A broadcasting station which uses a constant frequency band, broadcast data for a plurality of virtual channels,
Wherein the extracting comprises:
And filtering broadcast data corresponding to the identification information among broadcast data existing in the physical channel using the identification information of the broadcast data. The method according to claim 1,
Wherein the broadcast data and the communication data included in the physical channel are transmitted in the form of a data packet. delete The method according to claim 1,
Wherein the identification information of the broadcast data includes:
And the PID (Packet ID) information of the broadcast data is used. The method according to claim 1,
Wherein the determining comprises:
Identifying an idle frequency band within the physical channel; And
Selecting communication data to be added to the identified idle frequency band
/ RTI > 6. The method of claim 5,
Wherein the determining comprises:
The communication data to be added to the idle frequency band in the physical channel is decreased as the broadcast data to be transmitted in the physical channel is increased and the communication data to be added to the idle frequency band in the physical channel is increased as the broadcast data to be transmitted in the physical channel is decreased Channel switching method. The method according to claim 1,
Wherein the determining comprises:
And if broadcast data and communication data can be added equally to the idle frequency band in the physical channel, then the broadcast data is considered as priority. Identifying a physical channel for channel switching in a broadcast channel;
Determining an idle frequency band in which no broadcast data exists in the physical channel; And
Adding communication data to the idle frequency band of the physical channel and transmitting
Lt; / RTI >
Wherein the broadcast data and the communication data are classified according to identification information. Receiving broadcast data and communication data included in each of physical channels of a broadcast channel; And
Extracting communication data from each of the physical channels
Lt; / RTI >
The communication data is data added to the idle frequency band in the physical channel,
Wherein the broadcast data and the communication data are classified according to identification information. delete A generating unit for generating identification information of broadcast data corresponding to the virtual channel information by using the virtual channel information currently being viewed by the user,
An extracting unit for extracting broadcast data for a corresponding virtual channel existing in a physical channel by using information of a currently viewed virtual channel of a user;
A determination unit for determining communication data to be added to an idle frequency band in the physical channel in which the extracted broadcast data exists; And
A transmission unit for transmitting the transmission data stream generated using the broadcasting data and communication data included in the physical channel,
Lt; / RTI >
The extracting unit extracts,
Filtering broadcast data corresponding to the identification information among broadcast data existing in the physical channel using the identification information of the generated broadcast data,
The physical channel includes:
And uses broadcast data for a plurality of virtual channels using a constant frequency band. 12. The method of claim 11,
Wherein the broadcast data and the communication data included in the physical channel are transmitted in the form of a data packet. delete 12. The method of claim 11,
Wherein the identification information of the broadcast data includes:
And uses PID (Packet ID) information of the broadcast data. 12. The method of claim 11,
Wherein,
To identify the idle frequency band in the physical channel and to select communication data to be added to the identified idle frequency band. 16. The method of claim 15,
Wherein,
The communication data to be added to the idle frequency band in the physical channel is decreased as the broadcast data to be transmitted in the physical channel is increased and the communication data to be added to the idle frequency band in the physical channel is increased as the broadcast data to be transmitted in the physical channel is decreased Channel switching device. 12. The method of claim 11,
Wherein,
Wherein when the broadcast data and the communication data can be equally added to the idle frequency band in the physical channel, the channel switching device considers the broadcast data as priority. delete A receiver for receiving broadcast data and communication data included in each of physical channels of a broadcast channel; And
An extraction unit for extracting communication data from each of the physical channels,
Lt; / RTI >
The communication data is data added to the idle frequency band in the physical channel,
Wherein the broadcast data and the communication data are classified according to identification information. 20. The method of claim 19,
The extracting unit extracts,
And uses PID (Packet ID) information of the communication data.

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