Abstract:
A cable receiver is disclosed that comprises a multimedia channel unit to receive a multimedia signal, and a multimedia processor to process the multimedia signal. The cable receiver further comprises a cable modem to perform data communication with an information provider that provides appendix information about the multimedia signal and a Web server that hosts a predetermined Web page through a cable network. An information processor adds appendix information to the multimedia signal, and a Web browser transmits request information received for the Web page according to a user&#39;s selection and processes the received Web page for the user. The cable receiver further comprises a controller to control data transmission of the cable modem, the information processor, and the Web browser to transmit the appendix information and the Web page to the information processor and the Web browser. Thus, the present invention provides a cable receiver capable of supporting Internet service without incurring the additional cost associated with a cable modem.

Description:
PRIORITY 
     This application claims the benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 2005-0066468, filed on Jul. 21, 2005, in the Korean Intellectual Property Office, the entire disclosure of which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to cable receivers. More particularly, the present invention relates to cable receivers capable of supporting Internet service without an additional cost. 
     2. Description of the Related Art 
     A cable receiver such as a cable set-top box, a cable-ready television, or the like, receives a cable broadcasting signal composed of audio and video signals, and properly processes the received cable broadcasting signal to provide picture and sound.  FIG. 1  illustrates a cable television system  1  connected to a conventional cable receiver. 
     As shown in  FIG. 1 , a multiple services operator (MSO)  11  provides multimedia service for picture and sound, and various cable television services such as data service for information based on data. Further, an internet service provider (ISP)  12  provides Internet service. A headend  14  is used for a cable television headend and receives a cable television signal from the cable television system, thereby processing and distributing it. The headend  14  receives a service signal from the MSO  11  and/or the ISP  12  while performing data communication with the MSO  11  and/or the ISP  12  through the Internet protocol (IP) network  13 . Headend  14  retransmits the service signal to a cable network  15  as a local cable infrastructure. 
     A cable set-top box  16  or a cable ready television  18  receives the cable television signal from the headend  14  using the cable network  15 . A television  17  or cable ready television  18  provides a user with picture, sound and data service on the basis of the signal processed. Meanwhile, a cable modem  19  receives and processes an Internet service signal through the cable network  15 , and transmits it to a personal computer (PC)  20 , thereby providing a user with Internet service. Thus, the conventional cable receiver receives just the cable television signal, and processes and outputs it, but cannot directly process and provide Internet service. That is, the conventional cable receiver should additionally include cable modem  19  in order to provide internet service, which increases production cost. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an aspect of the present invention to provide a cable receiver capable of supporting Internet service without incurring additional cost. This and other aspects of the present invention can be achieved by providing a cable receiver comprising a multimedia channel unit to receive a multimedia signal, and a multimedia processor to process the multimedia signal. The cable receiver further comprises a cable modem to perform data communication with an information provider that provides appendix information about the multimedia signal and a Web server that hosts a predetermined Web page, through a cable network. The cable receiver further comprises an information processor to add the appendix information to the multimedia signal, a Web browser to transmit receiving request information for the Web page according to a user&#39;s selection, and process the received Web page to be used by a user. The cable receiver additionally comprises a controller to control data transmission of the cable modem, the information processor, and Web browser to transmit the appendix information and Web page to the information processor and Web browser. 
     According to another exemplary embodiment of the present invention, the cable receiver further comprises a data channel unit to transmit the appendix information to the information processor by performing data communication with the information provider through the cable network. 
     According to another exemplary embodiment of the present invention, the data channel unit is configured to transmit data about the appendix information from the information processor to the information provider through the cable network. 
     According to another exemplary embodiment of the present invention, the cable receiver further comprises a display unit to display a picture based on the multimedia signal processed by the multimedia processor, and the Web page processed by the Web browser. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, exemplary features and advantages of the present invention will become apparent and more readily appreciated from the following description of certain exemplary embodiments thereof, taken in conjunction with the accompany drawings, in which: 
         FIG. 1  is a block diagram illustrating a conventional cable television system; 
         FIG. 2  is a block diagram illustrating a cable television system according to an exemplary embodiment of the present invention; and 
         FIG. 3  is a block diagram schematically illustrating a configuration of a cable set-top box according to an exemplary embodiment of the present invention. 
     
    
    
     Throughout the drawings, like reference numbers should be understood to refer to like elements, features, and structures. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The matters exemplified in this description are provided to assist in a comprehensive understanding of various exemplary embodiments of the present invention disclosed with reference to the accompanying figures. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the exemplary embodiments described herein can be made without departing from the scope and spirit of the claimed invention. Descriptions of well-known functions and constructions are omitted for clarity and conciseness. 
       FIG. 2  is a block diagram illustrating a cable television system  100  according to an exemplary embodiment of the present invention. A multiple services operator (MSO)  110  provides multimedia service for picture and sound, and cable television service, such as data service for information based on data. Further, an Internet service provider (ISP)  120  provides Internet service. The headend  140  receives a service signal from the MSO  110  and/or ISP  120  while performing data communication with the MSO  110  and/or ISP  120  through an internet protocol (IP) network  130 , and retransmits the service signal to a cable network  150 . 
     The headend  140  executes quadrature amplitude modulation (QAM) for the cable television signal to transmit. The headend  140  is provided with a cable modem termination system (CMTS), thereby having the capacity for implementing high-speed data service. The CMTS employs an Ethernet interface for the IP network  130 , and a coaxial radio frequency (RF) interface for the cable network  150 . According to an exemplary embodiment of the present invention, a hybrid fiber coax (HFC) is employed for signal transmission of the cable network  150 , and transmits a radio frequency (RF) signal therethrough. 
     A cable set-top box  200  and a digital cable-ready (DCR) television  300  receive an RF signal through the cable network  150 . Here, the cable set-top box  200  and the DCR television  300  are described as examples of the cable receiver. The cable set-top box  200  and the DCR television  300  extract a cable television service signal from the RF signal received through the cable network  150 , and process multimedia data including video and audio data on the basis of the extracted cable television service signal, thus outputting picture and sound. Further, the cable set-top box  200  and the DCR television  300  extract a data service signal from the received RF signal, and add appendix information to the multimedia data on the basis of the extracted data service signal. 
     The cable set-top box  200  includes a cable modem  210  and a Web browser  220 . Also, the DCR television  300  includes a cable modem  310  and a Web browser  320 . The cable set-top box  200  and the DCR television  300  receive an Internet service signal while communicating data with the ISP  120 , thereby allowing a user to access Internet. The cable set-top box  200  is connected to a television  160  and transmits a processed video signal, an audio signal, and Internet data to the television  160 . 
       FIG. 3  is a block diagram schematically illustrating a configuration of a cable set-top box  200  according to an exemplary embodiment of the present invention. According to an exemplary embodiment of the present invention, the cable set-top box  200  includes a video tuner  231 , a forward data channel (FDC) tuner  232 , a return channel transmitter  233 , a data over cable service interface specification (DOCSIS) tuner  234 , a national television system committee (NTSC) demodulator (DEMOD)  235 , a quadrature amplitude modulation (QAM) DEMOD  236 , an out-of-band (OOB) DEMOD  237 , an OOB modulator (MOD)  238 , a DOCSIS MOD  239 , a QAM DEMOD  240 , a DOCSIS media access control (MAC)  241 , an OOB processor  242 , a conditional access (CA) system  243 , a copy protection (CP)  244 , a demultiplexer (DEMUX)/decoder (DECODE)  245 , a central processing unit (CPU)  246 , a multimedia processor  247 , an output unit  248 , an input unit  260 , and a Web browser  220 . The video tuner  231  selects and receives a preset frequency signal in the RF signal transmitted through the cable network  150 . The video tuner  231  receives a signal having a frequency corresponding to a multimedia service signal provided from the MSO  110 , for example, a signal having a frequency of 54 MHz through 864 MHz, and outputs the signal to the NTSC DEMOD  235 . The NTSC DEMOD  235  receives the signal output from the video tuner  231  and performs a process such as demodulation or the like. The NTSC DEMOD  235  processes an analog channel signal among the signals output from the video tuner  231 . The QAM DEMOD  236  processes a digital channel signal among the signals output from the video tuner  231 , and demodulates the digital channel signal by 64-QAM or 256-QAM to output it. 
     The FDC tuner  232  selects a signal having a frequency of 70 MHz through 130 MHz that was transmitted through an OOB FDC channel, and receives a signal having an OOB message. According to an exemplary embodiment of the present invention, the OOB message contains a control and information message transmitted from the MSO  110  to the cable set-top box  200 , and includes, for example, a conditional access (CA) message for controlling authority to use the cable television service, a system information (SI) message, an electronic program guide (EPG) message, and/or an emergency alert system (EAS) message. Here, the MSO  110  is described as an example of an information provider, and the OOB message is described as an example of appendix information. The OOB DEMOD  237  receives the signal output from the FDC tuner  232  and demodulates the signal to output the OOB message. The OOB DEMOD  237  can, for example, implement quadrature phase-shift keying in demodulation of the OOB message. In this exemplary embodiment, the FDC tuner  232  and the OOB DEMOD  237  are described as an example of a data channel unit. 
     The OOB processor  242  receives the OOB message from the OOB DEMOD  237 , and decodes and processes the OOB message through predetermined protocol. The CA system  243  receives the multimedia data from the QAM DEMOD  236 , and controls the authority to use the multimedia data according to the direction of the OOB processor  242  based on the OOB message. The CP  244  protects the multimedia data from duplication. Here, the OOB processor  242 , the CA system  243 , and the CP  244  are described as an information processor, and can be realized by a cable card  250 . 
     When there is no cable card, the DEMUX/DECODE  245  performs demultiplexing and performs decoding for the multimedia data transmitted from the CA system  243 . The multimedia processor  247  performs, for example, NTSC encoding, graphic processing, vertical blanking interval (VBI) data inserting, AC-3 decoding, and image processing for the multimedia data output from the NTSC DEMOD  235  and the DEMUX/DECODE  245 . The output unit  248  outputs the signal processed by the multimedia processor  247  and having various video and audio formats such as, for example, RCA, DVI/HDMI, S-VHS, S/PDIF. Here, the video tuner  231 , the NTSC DEMOD  235 , and the QAM DEMOD  236  are described as an example of a multimedia channel unit. 
     Meanwhile, when there is upstream transmission in a reverse data channel (RDC) from the cable set-top box  200  to the MSO  110  via the headend  140 , the OOB MOD  238  and the return channel transmitter  233  modulate and transmit the data to be transmitted from the OOB processor  242 . 
     When the OOB message is received from the MSO  110  through a DOCSIS set-top gateway (DSG) channel, the DOCSIS tuner  234  receives a signal having a frequency corresponding to a downstream channel of the DSG channel, for example, a signal having a frequency of 54 MHz through 864 MHz, and outputs it. The QAM DEMOD  240  can use the 64-QAM or the 256-QAM to demodulate the signal output from the DOCSIS tuner  234  and to output it. The DOCSIS MAC  241  is interposed between the QAM DEMOD  240  and the CPU  246 , and performs data communication for the OOB message with a DSG server provided in the MSO  110  through the CMTS according to a suitable protocol, such as that provided by the DSG interface specification of CableLabs, the entire disclosure of which is hereby incorporated by reference. The DOCSIS MAC  241  communicates the data with the CPU  246  through the Ethernet interface. Then, the CPU  245  controls the signal, which is obtained by the data communication of the DOCSIS MAC  241 , to be transmitted to the OOB processor  242 . Further, the OOB processor  242  processes the OOB message included in the received signal. In the meantime, when there is upstream transmission in the DSG channel from the cable set-top box  200  to the MSO  110 , or the ISP  120  via the headend  140 , the DOCSIS MAC  241  uses the DOCSIS MOD  239  to modulate the signal and uses the return channel transmitter  233  to transmit the modulated signal. In this exemplary embodiment, the DOCSIS tuner  234 , the QAM DEMOD  240 , the DOCSIS MAC  241 , the DOCSIS MOD  239 , and the return channel transmitter  233  are included in the cable modem  210 . 
     The Web browser  220  communicates data with a predetermined Web server according to a suitable protocol such as hypertext transfer protocol (HTTP), thereby allowing a user to access a Web page or the like hosted by a Web server provided by the ISP  120 . In this case, the cable modem  210  is used in performing data communication according to sub-network protocol, such as a data link layer, needed for transmitting data between the Web browser  220  and the Web server. When a user selects the Web page hosted by the Web server through the input unit  260 , the CPU  246  controls the data transmission of the Web browser  220  and the cable modem  210  to receive the Web page from the Web server. Here, the CPU  246  can transmit the Web page received by the Web browser as a file format to the television  160 . In this exemplary embodiment, the Web browser may be implemented by a software application. 
     The DCR television  300  may have the same configuration as that of the foregoing cable set-top box  200 . Further, the DCR television  300  displays the Web page received by the Web browser  220  on a display unit, thus allowing a user to see the Web page. 
     Thus, when the DSG channel, as well as the OOB FDC channel, is selected for transmitting and processing the appendix information about a multimedia signal such as the OOB message. The cable receiver for processing the multimedia signal should include the cable modem, which performs the data communication based on DOCSIS, in order to process such appendix information. The DOCSIS cable modem is not different in structure from a cable modem needed for performing the data communication based on Internet protocol through a cable network. Therefore, when the Web browser is added to the cable receiver having the cable modem for DSG operation, the cable receiver can support the Internet service without incurring the additional cost of a traditional cable modem. The present invention therefore provides a cable receiver capable of supporting Internet service without incurring additional cost. 
     While the present invention has been particularly shown and described with reference to certain exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and equivalents thereof.