METHOD AND DEVICE FOR PROVIDING LOCAL BROADCASTING SERVICES

Technical Field

[1] The present invention relates to a method and device for providing a local broadcasting service. Particularly, the present invention relates to a method and device for providing a local broadcasting service based on advanced terrestrial digital multimedia broadcasting (AT-DMB). Background Art

[2] The terrestrial digital multimedia broadcasting (T-DMB) represents a broadcasting system that is generated by adding a multimedia broadcasting service including a video service to the Eureka 147-based digital audio broadcasting (DAB) system.

[3] The advanced terrestrial digital multimedia broadcasting (AT-DMB) represents a broadcasting system that is generated by doubling transmission data capacity by adding a new hierarchical modulation method based on the T-DMB. The AT-DMB uses the same frequency bandwidth as the existing T-DMB, increases the transmission capacity by up to twice to provide a greater number of services, and provides the standard definition (SD) level video service that is four times better than the T-DMB image quality.

[4] After the T-DMB became commercially available, discussion on diversity of broadcasting services and quality of services has progressed for the purpose of industry activation. As part of the discussion, repeaters and gap fillers have been provided in areas with many buildings or in blanket areas such as inside tunnels so as to increase the broadcasting service quality. Also, traffic broadcasting services and bi-directional services have been provided to emphasize the diversity of broadcasting and activate related fields of industry.

[5] Further, discussion for solving the problem by providing local broadcasting services based on the existing T-DMB has been undertaken. However, these methods worsen usage efficiency of frequencies since the frequency of the local broadcasting signal is different from the frequency of the main broadcasting signal.

[6] In addition, when the same frequency is used, the available channel capacity becomes very much less because of retransmission of the main broadcasting signals, and many technical problems are generated because of signal interference.

[7] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Disclosure of Invention

Technical Problem

[8] The present invention has been made in an effort to provide a method and device that are compatible with the existing T-DMB for providing a new local broadcasting service by using the AT-DMB. Technical Solution

[9] An exemplary embodiment of the present invention provides a method for providing a local broadcasting service in a local broadcasting system that includes: receiving a first main broadcasting signal from a terrestrial digital multimedia broadcasting system; converting the first main broadcasting signal into a second main broadcasting signal for local broadcasting; generating a second local broadcasting signal by encoding the first local broadcasting signal to be broadcast; and performing hierarchical modulation on the second main broadcasting signal and the second local broadcasting signal, and transmitting the signals.

[10] Another exemplary embodiment of the present invention provides a device for providing a local broadcasting service in a local broadcasting system including: a signal converter for converting a first main broadcasting signal that is appropriate for long distance transmission of greater than a reference distance into a second main broadcasting signal that is appropriate for local distance transmission of less than a reference distance; a local signal encoder for generating a second local broadcasting signal by encoding a first local broadcasting signal to be broadcast; a local signal inserter for generating a third main broadcasting signal by inserting information for notifying existence of the local broadcasting signal into the second main broadcasting signal; and a hierarchical modulator for generating a fourth broadcasting signal by hierarchically modulating the second local broadcasting signal and the third main broadcasting signal, and transmitting the fourth broadcasting signal.

Advantageous Effects

[11] According to the exemplary embodiment of the present invention, new local broadcasting services can be provided while the existing T-DMB broadcasting service is provided by using the T-DMB and AT-DMB broadcasting system. Also, regarding the T-DMB broadcasting, a device for providing the local broadcasting service is used as a T-DMB relay system to improve the broadcasting quality such as solving the problem of the blanket area, and simultaneously, the AT-DMB system is used to provide a local broadcasting service in the same frequency bandwidth and thereby provide convenience to the local user. Brief Description of Drawings [12] FIG. 1 shows an example of an environment for providing a local broadcasting service using the T-DMB and AT-DMB network according to an exemplary embodiment of the present invention.

[13] FIG. 2 shows a hierarchical structure of an ensemble transport interface according to an exemplary embodiment of the present invention.

[14] FIG. 3 is a block diagram for showing a transmitting device of a local broadcasting system of FIG. 1.

[15] FIG. 4 is a flowchart for providing a local broadcasting service according to an exemplary embodiment of the present invention. Mode for the Invention

[16] In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

[17] Throughout the specification, unless explicitly described to the contrary, the word

"comprise" and variations such as "comprises" or "comprising" will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms "-er", "-or" and "module" described in the specification mean units for processing at least one function and operation and can be implemented by hardware components or software components and combinations thereof.

[18] In the specification, a mobile station (MS) may indicate a terminal, a mobile terminal

(MT), a subscriber station (SS), a portable subscriber station (PSS), user equipment (UE), and an access terminal (AT), and it may include entire or partial functions of the terminal, the mobile terminal, the subscriber station, the portable subscriber station, the user equipment, and the access terminal.

[19] In the specification, a base station (BS) may indicate an access point (AP), a radio access station (RAS), a nodeB (Node-B), an evolved Node-B (eNB), a base transceiver station (BTS), and a mobile multihop relay (MMR)-BS, and it may include entire or partial functions of the access point, the radio access station, the nodeB, the evolved Node-B, the base transceiver station, and the mobile multihop relay-BS.

[20] Hereinafter, a method and device for providing a local broadcasting service according to an exemplary embodiment of the present invention will be described with reference to accompanying drawings.

[21] FIG. 1 shows an example of an environment for providing a local broadcasting service using the T-DMB and AT-DMB network according to an exemplary embodiment of the present invention. [22] As shown in FIG. 1, the environment for providing a local broadcasting service includes a T-DMB broadcasting system 10, a T-DMB main transmitter 20, a local broadcasting system 30, and a local transmitter 40. [23] The T-DMB broadcasting system 10 transmits T-DMB broadcasting signals that are generated by combining a plurality of broadcasting programs through a channel. [24] In detail, the T-DMB broadcasting system 10 configures various broadcasting programs that are services into a single ensemble by using an ensemble multiplexer

(not shown), generates signals according to the ensemble transport interface (ETI) standard, and transmits them as T-DMB broadcasting signals. In this instance, the T-

DMB broadcasting system 10 transmits the T-DMB broadcasting signals to the T-

DMB main transmitter 20 and the local broadcasting system 30 through an optical network or a microwave network. [25] The T-DMB main transmitter 20 transmits the T-DMB broadcasting signals to a service area that is wider than the basic service area with great transmission power. [26] The local broadcasting system 30 inserts local broadcasting signals into the T-DMB broadcasting signals that are received through the optical network or the microwave network to generate AT-DMB broadcasting signals, and transmits the AT-DMB broadcasting signals to the local transmitter 40. [27] The local transmitter 40 transmits the AT-DMB broadcasting signals to a service area that is narrower than the basic service area with less transmission power. [28] A hierarchical structure of the ETI according to an exemplary embodiment of the present invention will now be described with reference to FIG. 2. [29] FIG. 2 shows a hierarchical structure of an ensemble transport interface according to an exemplary embodiment of the present invention. [30] First, the ensemble transport interface (ETI) represents a basic interface for the DMB network. [31] As shown in FIG. 2, the hierarchical structure of the ETI is defined to include a logical interface (LI) layer, a network independent (NI) layer, and a network adaptation

(NA) layer. [32] The LI layer represents a basic logical structure to define basic information for generating the ensemble. [33] The NI layer represents a simple physical interface layer for mapping the LI, and includes a basic interface for the ETI related equipment. [34] The NA layer represents a physical interface layer in the error protected format to be used in the network environment with an error generation probability compared to the

NI layer, and is mapped on the LI layer. [35] Also, the ETI includes various types of interfaces including the ETI(NI, G.703), the

ETI(NI, V.11), and the ETI(NA, G.704) according to the used interface signal types, and the ETI(NI, G.703) is used as the main interface among the ensemble transmitting equipment and is a standard input interface of the COFDM modulator.

[36] A transmitting device of the local broadcasting system 30 according to an exemplary embodiment of the present invention will now be described with reference to FIG. 3.

[37] FIG. 3 is a block diagram for showing a transmitting device of a local broadcasting system of FIG. 1.

[38] As shown in FIG. 3, the transmitting device 300 of the local broadcasting system 30 includes a signal converter 310, a local signal encoder 320, a local signal inserter 330, a hierarchical modulator 340, and a transmitter 350.

[39] The transmitting device 300 receives the first main broadcasting signal ETI(NA)_M from the T-DMB broadcasting system 10. Here, the first main broadcasting signal ETI(NA)_M represents a T-DMB main broadcasting signal that is appropriate for long-distance transmission of greater than the reference distance.

[40] The signal converter 310 converts the second main broadcasting signals ETI(NI)_M that are received through the optical network or the microwave network into baseband signals. The signal converter 310 converts the first main broadcasting signal ETI(NA)_M into the second main broadcasting signal ETI(NI)_M that is appropriate for short-distance transmission that is less than the reference distance to satisfy the T- DMB standard, and transmits the second main broadcasting signal ETI(NI)_M to the local signal encoder 320.

[41] The local signal encoder 320 encodes source signals of first local broadcasting signals including the received video, audio, and data, and provides a local broadcasting service.

[42] In detail, the local signal encoder 320 encodes the first local broadcasting signals to generate second local broadcasting signals including the ETI(NI)_L defined by the T- DMB standard and individual definition signals through the service transport interface STI or the Ethernet. Here, the STI represents an interface between transmission devices for transmitting one program defined by the Eureka- 147 DAB standard. Also, the local signal encoder 320 transmits the second local broadcasting signal in the ETI(NI)_L to the local signal inserter 330.

[43] The local signal inserter 330 generates a third main broadcasting signal ETI(NI)_M2 by inserting information for notifying existence of local broadcasting signals into the second main broadcasting signal ETI(NI)_M, and transmits the third main broadcasting signal ETI(NI)_M2 to the hierarchical modulator 340.

[44] Also, the local signal inserter 330 converts the second local broadcasting signal including the individual definition signals through the STI or the Ethernet into a third local broadcasting signal ETI(NI)_L, and transmits the third local broadcasting signal ETI(NI)_L to the hierarchical modulator 340. In this instance, the second local broadcasting signal is transmitted to the hierarchical modulator 340 when the format of the second local broadcasting signal is the same as the third local broadcasting signal ETl(NTLL.

[45] The hierarchical modulator 340 generates a fourth broadcasting signal (AT-DMB broadcasting signal) by performing hierarchical modulation (HM) on the two signals, that is, the third main broadcasting signal ETI(NI)_M2 and the third local broadcasting signal ETI(NI)_L.

[46] The hierarchical modulator 340 economically uses the frequency bandwidth by performing hierarchical modulation on the third main broadcasting signal ETI(NI)_M2 and the third local broadcasting signal ETI(NI)_L, and generates an AT-DMB broadcasting signal, and uses the AT-DMB broadcasting signal to simultaneously transmit the third main broadcasting signal ETI(NI)_M2 and the third local broadcasting signal ETI(NI)_L, that is, the T-DMB main broadcasting signal and the local broadcasting signal.

[47] The transmitter 350 transmits the AT-DMB broadcasting signal that is generated by performing hierarchical modulation and inserting the local broadcasting signal into the T-DMB main broadcasting signal to the local transmitter 40.

[48] A method for providing a local broadcasting service according to an exemplary embodiment of the present invention will now be described with reference to FIG. 4.

[49] FIG. 4 is a flowchart for providing a local broadcasting service according to an exemplary embodiment of the present invention.

[50] The local broadcasting system 30 providing a local broadcasting service receives the

T-DMB main broadcasting signal, that is, the first main broadcasting signal ETI(NA)_M from the T-DMB broadcasting system 10 through the optical network or the microwave network. Here, the first main broadcasting signal ETI(NA)_M represents the T-DMB main broadcasting signal that is longer than the reference distance.

[51] The local broadcasting system 30 converts the first main broadcasting signal

ETI(NI)_M that is received through the optical network or the microwave network into a baseband band signal, and converts the first main broadcasting signal ETI(NA)_M into the second main broadcasting signal ETI(NI)_M appropriate for local transmission (SlOO).

[52] The local broadcasting system 30 encodes the first local broadcasting signal to generate a second local broadcasting signal S200 defined by the T-DMB standard.

[53] The local broadcasting system 30 inserts information for notifying existence of the local broadcasting signal into the second main broadcasting signal ETI(NI)_M to generate a third main broadcasting signal ETI(NI)_M2, and converts the encoded second local broadcasting signal into the same format of the ETI(NI)_L to generate a third local broadcasting signal ETI(NI)_L (S300). In this instance, the second local broadcasting signal is not converted when the received second local broadcasting signal has the same format as the ETI(NI)_L.

[54] The local broadcasting system 30 performs hierarchical modulation on the two generated signals, that is, the third main broadcasting signal ETI(NI)_M2 and the third local broadcasting signal ETI(NI)_L, to generate a fourth broadcasting signal (AT-DMB broadcasting signal) (S400).

[55] In detail, the local broadcasting system 30 inserts the third local broadcasting signal

ETI(NI)_L into the third main broadcasting signal ETI(NI)_M2 to generate a fourth broadcasting signal (AT-DMB broadcasting signal). That is, the local broadcasting system 30 inserts the third local broadcasting signal ETI(NI)_L into the third main broadcasting signal ETI(NI)_M2 to generate a fourth broadcasting signal (AT-DMB broadcasting signal) in order to simultaneously transmit the local broadcasting signal and the T-DMB main broadcasting signal.

[56] The local broadcasting system 30 transmits the fourth broadcasting signal (AT-DMB broadcasting signal) to the local transmitter 40 (S500).

[57] Accordingly, the method for providing a local broadcasting service according to the exemplary embodiment of the present invention provides a local broadcasting service in a specific area to provide convenience to the user while providing compatibility with the T-DMB broadcasting.

[58] The above-described embodiments can be realized through a program for realizing functions corresponding to the configuration of the embodiments or a recording medium for recording the program in addition to through the above-described device and/or method, which is easily realized by a person skilled in the art.

[59] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.