Abstract:
A method of obtaining additional network information in digital satellite broadcasting. The method includes extracting a boot object including information of each network from a digital satellite broadcast signal, determining whether the information of each network included in the boot object is extended network information, checking validity of the extended network information, and storing the extended network information when the extended network information is determined as being valid.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority from Korean Patent Application No. 2004-0066277 filed on Aug. 23, 2004 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to satellite broadcasting, and more particularly, to a method of obtaining additional network information in satellite broadcasting.  
         [0004]     2. Description of Related Art  
         [0005]     Broadcasting from satellite broadcasting to terrestrial broadcasting has been rapidly digitized and united with communication. With the development of compression and error correction technology for digital signals and the rapid improvement of semiconductor integration technology, the price of a digital broadcast receiver and the cost for transmitting digital signals have been decreased. As a result, people have been able to enjoy digital broadcasting at home. Digital broadcasting that has been put to practical use may be divided into digital terrestrial broadcasting, digital cable broadcasting, and digital satellite broadcasting. Of those, commercial digital satellite broadcasting began with DIRECTV® in the United States in 1994. Since 1996, new multi-channel satellite broadcast providers have participated in commercial digital satellite broadcasting in earnest.  
         [0006]     A Moving Picture Experts Group (MPEG) standard is used for signal coding and multiplexing in common in different types of digital satellite broadcasting. However, parts such as program identification and pay type that are close to the details of service and transmission including error correction have been performed according to individual specifications. Accordingly, people cannot view all satellite broadcasts with a single satellite broadcast receiver.  
         [0007]     To receive a satellite broadcast, a satellite broadcast receiver must have information on a satellite transmitting a satellite broadcast signal. DIRECTV® satellite broadcasting uses fixed network settings, i.e., Round, Oval-2, and Oval-3. The Round uses a satellite having a network ID of 0. The Oval-2 uses a satellite having a network ID of 0 and a satellite having a network ID of 3. The Oval-3 uses a satellite having a network ID of 0, a satellite having a network ID of 2, and a satellite having a network ID of 3. The network ID of 0 indicates a satellite (corresponding to Sat-A) having an orbital position of 101°. The network ID of 2 indicates a satellite (corresponding to Sat-C) having an orbital position of 110°. The network ID of 3 indicates a satellite (corresponding to Sat-B) having an orbital position of 119°.  
         [0008]      FIG. 1  is a flowchart of a booting procedure of a DIRECTV® satellite broadcast receiver.  
         [0009]     When the power of the satellite broadcast receiver is turned on, the satellite broadcast receiver receives a satellite signal from a satellite set in default in operation S 110 .  
         [0010]     After receiving the satellite signal, the satellite broadcast receiver demodulates and demultiplexes the received satellite signal and extracts a boot object in operation S 120 .  
         [0011]     After extracting the boot object, the satellite broadcast receiver loads network information stored in nonvolatile memory in operation S 130 . The network information is information on a fixed satellite that a DIRECTV® broadcast provider has had. A user can select one among satellite settings Round, Oval-2, and Oval-3 in a DIRECTV® satellite broadcast receiver.  
         [0012]     Next, the satellite broadcast receiver checks the validity of the network information read from the nonvolatile memory in operation S 140 .  
         [0013]     Thereafter, the satellite broadcast receiver determines whether user input has been made in operation S 150 . When no user input has been made, the satellite broadcast receiver continues the booting procedure using fixed satellite network IDs of 0, 2, and 3, satellite transponders corresponding to the respective network IDs, and frequency information in operation S 170 . When user input has been made, the satellite broadcast receiver performs Digital Satellite Equipment Control (DiSEqC) configuration according to the user input in operation S 160 .  
         [0014]     In such conventional booting procedure, booting or DiSEqC configuration is performed only with respect to fixed satellite information, i.e., network IDs of 0, 2, and 3. When a new satellite is added according to the change in a broadcasting environment, a satellite broadcast receiver cannot effectively obtain information on the new satellite in the conventional booting procedure. Therefore, a method of effectively obtaining information on a new satellite is desired.  
       BRIEF SUMMARY  
       [0015]     An aspect of the present invention provides a method of effectively obtaining additional network information in satellite broadcasting.  
         [0016]     According to an aspect of the present invention, there is provided a method of obtaining additional network information in digital satellite broadcasting. The method includes extracting a boot object including information of each network from a digital satellite broadcast signal, determining whether each network information included in the boot object is extended network information, checking validity of the extended network information, and storing the extended network information when the extended network information is determined to be valid.  
         [0017]     According to another aspect of the present invention, there is provided a method of obtaining additional network information in digital satellite broadcasting, the method including extracting a boot object including information of each network from a digital satellite broadcast signal, determining whether the information of each network included in the boot object is extended network information, checking validity of the extended network information, determining whether the extended network information has already been stored when the extended network information is determined to be valid, and storing the extended network information determined to be valid when it is determined that the extended network information has not been stored.  
         [0018]     According to another aspect of the present invention, there is provided a satellite broadcast receiver, including: an extracting section extracting a boot object including information of each network from a digital satellite broadcast signal; a central processing unit determining whether the information of each network included in the boot object is extended network information and checking validity of the extended network information; and a storage unit storing the extended network information when the extended network information is determined to be valid.  
         [0019]     According to other aspects of the present invention, there are provided computer-readable storage media encoded with processing instructions for causing a processor to execute the above-described methods.  
         [0020]     Additional and/or other aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     The above and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings of which:  
         [0022]      FIG. 1  is a flowchart of a conventional booting procedure of a satellite broadcast receiver;  
         [0023]      FIG. 2  is a block diagram of a satellite broadcast receiver according to an embodiment of the present invention;  
         [0024]      FIG. 3  is a flowchart of a booting procedure of a satellite broadcast receiver according to an embodiment of the present invention; and  
         [0025]      FIG. 4  is a flowchart of a booting procedure of a satellite broadcast receiver according to another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0026]     Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
         [0027]      FIG. 2  is a block diagram of a satellite broadcast receiver according to an embodiment of the present invention.  
         [0028]     The satellite broadcast receiver includes a tuner  202 , a demodulator  204 , a demultiplexer  206 , a decoder  208 , a video output unit  210 , a conditional access system (CAS)  212 , an audio output unit  214 , a nonvolatile memory  216 , a central processing unit  218 , a dynamic random access memory (DRAM)  220 , and a storage unit  222 .  
         [0029]     The tuner  202  selects a satellite broadcast signal of a channel having a particular frequency among satellite broadcast signals received through a satellite broadcast antenna (not shown). In digital broadcasting, a channel is used to transmit one or more programs or data.  
         [0030]     The demodulator  204  demodulates the satellite broadcast signal selected by the tuner  202  to obtain a transport stream. For example, when the satellite broadcast signal has been modulated using quadrature phase shift keying (QPSK) modulation, the demodulator  204  can obtain a transport stream by demodulating the satellite broadcast signal using QPSK demodulation. Besides, binary phase shift keying (BPSK) and quadrature amplitude modulation (QAM) may be used for demodulation.  
         [0031]     The demultiplexer  206  separates a video stream, an audio stream, and data from the transport stream. For example, when receiving a Moving Picture Experts Group (MPEG)-2 transport stream, the demultiplexer  206  can separate a video stream, an audio stream, and a data stream using a Packet IDentifier (PID).  
         [0032]     The decoder  208  may include a video decoder, an audio decoder, or a data parser.  
         [0033]     The decoder  208  reconstructs video data from the video stream using video decompression such as MPEG-2 decompression or MPEG4 decompression, reconstructs audio data using audio decompression such as MPEG Layer-3 (MP3) decompression or audio compression-3 (AC-3) decompression, and restores data by decompressing the data stream using normal data decompression. The reconstructed video data is provided to the video output unit  210 . The reconstructed audio data is provided to the audio output unit  214 . The restored data may be stored in the storage unit  222  in a file format or may be processed by the central processing unit  218 . For example, when the restored data is caption data, the caption data is provided to the video output unit  210 .  
         [0034]     The video output unit  210  processes the reconstructed video data and provides the processed result to a display apparatus (not shown). For example, the video output unit  210  processes the reconstructed video data using an NTSC encoder. However, it is to be understood that this is just an example and the video output unit  210  may process the reconstructed video data using a PAL encoder instead.  
         [0035]     The audio output unit  214  processes the reconstructed audio data and provides the processed result to a speaker (not shown). For example, the audio output unit  214  processes the reconstructed audio data using a digital-to-analog converter (DAC) to generate an analog audio signal.  
         [0036]     The CAS  212  restricts reception of a particular broadcast program using encryption. To view the restricted broadcast program, a user needs to buy and insert a smart card into the satellite broadcast receiver when driving the CAS  212 . When the smart card is inserted, the CAS  212  releases the particular broadcast program from the reception restriction so that the user can view the particular broadcast program.  
         [0037]     The central processing unit  218  controls the entire system of the satellite broadcast receiver and may be implemented as a microprocessor. Although the central processing unit  218  is separately implemented in  FIG. 2 , it may be included within the demultiplexer  206  or the decoder  208 . The central processing unit  218  can perform operations according to a user&#39;s command input through a user interface (not shown).  
         [0038]     The nonvolatile memory  216  stores information needed for a booting procedure of the satellite broadcast receiver. For example, the nonvolatile memory  216  may store network information and a program for executing the booting procedure. The nonvolatile memory  216  may be implemented as an electrically erasable programmable read-only memory (EEPROM) or a flash memory.  
         [0039]     The DRAM  220  temporarily stores data while the decoder  208  reconstructs video or audio data or restores normal data. In addition, the DRAM  220  temporarily stores program codes needed by the central processing unit  218  to control the entire system of the satellite broadcast receiver.  
         [0040]     The storage unit  222  stores restored data or a video or audio stream and may be implemented as a hard disc drive.  
         [0041]     The term ‘module’, as used herein, means, but is not limited to, a software or hardware component, such as a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks. A module may advantageously be configured to reside on the addressable storage medium and configured to execute on one or more processors. The functionality provided for in the components and modules may be combined into fewer components and modules or further separated into additional components and modules. In addition, the components and modules may be implemented such that they execute one or more computers in a communication system.  
         [0042]      FIG. 3  is a flowchart of a booting procedure of a satellite broadcast receiver according to an embodiment of the present invention.  
         [0043]     When the power of the satellite broadcast receiver is turned on, the satellite broadcast receiver receives a satellite signal from a satellite set in default in operation S 310 .  
         [0044]     After receiving the satellite signal, the satellite broadcast receiver demodulates and demultiplexes the satellite signal to extract a boot object in operation S 320 .  
         [0045]     In a DIRECTV® standard, the boot object is included in an advanced program guide (APG) and becomes a start point of the satellite broadcast receiver. The boot object is transmitted in a boot stream having a service channel ID (SCID) of 0x800 and includes guide information regarding all networks. Upon receiving the boot object, the satellite broadcast receiver can find information regarding a desired network, for example, network  0 . The boot object includes information regarding a place to which guide data for each network is transmitted. This information includes a fast load stream frequency index (frequency_index), a SCID, and a network&#39;s carousel information stream SCID.  
         [0046]     After extracting the boot object, the satellite broadcast receiver loads the information of each network from the boot object in operation S 330 .  
         [0047]     Thereafter, the satellite broadcast receiver determines whether extended network information is present in operation S 340 . The extended network information indicates a network other than existing fixed satellites, i.e., default networks having network IDs of 0, 2, and 3.  
         [0048]     If the extended network information is present, the satellite broadcast receiver checks a frequency range and a polarization value in operation S 342 . Next, the satellite broadcast receiver determines whether the extended network information has a valid frequency range and polarization value in operation S 344 . When it is determined that the extended network information has a valid frequency range and polarization value, the satellite broadcast receiver stores the valid extended network information in a DRAM in operation S 346 .  
         [0049]     If the extended network information is not present or if the extended network information does not have a valid frequency range or polarization value, operation S 346  is omitted.  
         [0050]     Through operations S 340  to S 346 , the satellite broadcast receiver can store information regarding a new additional network (or satellite) in the DRAM. The information stored in the DRAM can be utilized in booting (operation S 370 ) or Digital Satellite Equipment Control (DiSEqC) configuration (operation S 360 ).  
         [0051]     Thereafter, the satellite broadcast receiver determines whether a user input has been made in operation S 350 . If no user input has been made, the satellite broadcast receiver continues the booting procedure using the stored default network information or extended network information in operation S 370 . However, if a user input has been made, the satellite broadcast receiver performs DiSEqC configuration according to the user input in operation S 360 .  
         [0052]     Since the extended network information is stored in the DRAM, when the satellite broadcast receiver is newly booted, the stored extended network information disappears and the satellite broadcast receiver newly obtains the extended network information through operations S 340  to S 346 . If new extended network information is received, it is also stored in the DRAM.  
         [0053]      FIG. 4  is a flowchart of a booting procedure of a satellite broadcast receiver according to another embodiment of the present invention.  
         [0054]     When the power of the satellite broadcast receiver is turned on, the satellite broadcast receiver receives a satellite signal from a satellite set in default in operation S 410 .  
         [0055]     After receiving the satellite signal, the satellite broadcast receiver demodulates and demultiplexes the satellite signal to extract a boot object in operation S 420 .  
         [0056]     After extracting the boot object, the satellite broadcast receiver loads the information of each network from the boot object in operation S 430 .  
         [0057]     Thereafter, the satellite broadcast receiver determines whether extended network information is present in operation S 440 . The extended network information indicates a network other than existing fixed satellites, i.e., default networks having network IDs of 0, 2, and 3.  
         [0058]     If the extended network information is present, the satellite broadcast receiver checks a frequency range and a polarization value in operation S 442 . Next, the satellite broadcast receiver determines whether the extended network information has a valid frequency range and polarization value in operation S 444 . When it is determined that the extended network information has a valid frequency range and polarization value, the satellite broadcast receiver determines whether the extended network information has already been stored in a nonvolatile memory in operation S 445 . When it is determined that the extended network information has not been stored in the nonvolatile memory, the satellite broadcast receiver stores the valid extended network information in the nonvolatile memory in operation S 446 .  
         [0059]     If the extended network information is not present, if the extended network information does not have a valid frequency range or polarization value, or if the extended network information has already been stored, operation S 446  is omitted.  
         [0060]     Through operations S 440  to S 446 , the satellite broadcast receiver can store information regarding a new additional network (or satellite) in the nonvolatile memory. The information stored in the nonvolatile memory can be utilized in booting (operation S 470 ) or Digital Satellite Equipment Control (DiSEqC) configuration (operation S 460 ).  
         [0061]     Thereafter, the satellite broadcast receiver determines whether a user input has been made in operation S 450 . If no user input has been made, the satellite broadcast receiver continues the booting procedure using the stored default network information or extended network information in operation S 470 . However, if a user input has been made, the satellite broadcast receiver performs DiSEqC configuration according to the user input in operation S 460 .  
         [0062]     Since the extended network information is stored in the nonvolatile memory, even when the satellite broadcast receiver is newly booted, the stored extended network information does not disappear. Accordingly, the booting procedure according to the embodiment illustrated in  FIG. 4  further includes determining whether the extended network information has already been stored (operation S 445 ) compared to the booting procedure according to the embodiment illustrate in  FIG. 3 .  
         [0063]     According to the above-described embodiments of the present invention, when a new satellite is added in satellite broadcasting, a satellite broadcast receiver can obtain information regarding the new satellite so that new satellite information can be utilized in booting or DiSEqC configuration.  
         [0064]     Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.