Description
MULTI-OUT BROADCASTING RECEIVER SYSTEM USING CAS OF SINGLE SET-TOP BOX
Technical Field
[1] The present invention relates a multi-out broadcasting receiver system using conditional access system (hereinafter, "CAS") of a single set-top box, and more specifically to a multi-out broadcasting receiver system using CAS of a single set-top box which enables, under connection between a set-top box and multiple of TV receivers each positioned in distant locations through a pre-installed network of TV RF line in a house, the coexistence of remocon IR data and TV RF A/V signal in the RF line by adopting filter technology and the descrambling of more than two channels respectively scrambled using a single certificate card, so that a user may indepently watch multiple TV's in each of distant locations using a single set-top box. Further, thre present invention relates to a multi-out broadcasting receiver system using CAS of a single set-top box which enables remote control of a set-top box using a remocon from a distant location where the set-top box is not positioned.
[2]
Background Art
[3] According as fast development of digital technologies as to digital video encoding or digital modulation/demodulation, the standardization and commercialization for digital TV is fast launching. Under this situation, a digital broadcasting receiver for receiving digital television broadcast, e.g. set-top box (hereinafter, "STB"), helps users seletively watch the broadcast program by reconstructing, using a built-in decoder, origianl A/V (Audio/Video) data for a user-selected broadcast program and outputing the reconstructed to a A/V output device, e.g. TV.
[4] Further, recently in most of houses, each room is equipped a TV for its own. If these TV's are connected to single STB, it has advantage that through these TV's, users may watch satellite broadcast, cable broadcast, and digital terrestrial broadcast, etc.
[5] However, the prior art technology of connecting multiple of TV's to a single STB has problems that loss is engaged during signal transmission from STB to each room and cable engineering is further needed, which results in cost and difficulties for installation.
[6] Further, the prior art technology of connecting multiple of TV's to a single STB has problems that a rather expensive RF (UHF) remocon should be additionaly required in order to control the STB from a distant location where the STB is not positioned.
[7] Further, the prior art technology of providing a set-top box for each of TV sets has problems that certificate card should be provided for each of set-top boxes in order to descramble program channels. [8]
Disclosure of Invention
Technical Problem
[9] Therefore, an object of the present invention is to provide a multi-out broadcasting receiver system using CAS of single STB which enables, under connection between a set-top box and multiple of TV receivers each positioned in distant locations through a pre-installed network of TV RF line in a house, the coexistence of remocon IR data and TV RF A/V signal in the RF line by adopting filter technology and the de- scrambling of more than two channels respectively scrambled using a single certificate card, so that a user may indepently watch multiple TV's in each of distant locations using a single set-top box, and further the remote control of a set-top box using a remocon from a distant location where the set-top box is not positioned.
[10]
Technical Solution
[11] For accomplishing the object, the multi-out broadcasting receiver system using
CAS of single set-top box according to an embodiment of the present invention, comprising: a set-top box, which including, a first broadcast processing module, by a user operation, for selecting a channel of broadcast signal received from external transmission medium, a second broadcast processing module, upon receiving remocon control signal, for selecting a channel of the broadcast signal received from external tranmission medium, modulating A/V broadcast signal of the selected channel (hereinafter, "A/V remote broadcast signal") to a predetermined broadcast frequency, and outputting the A/V remote broadcast signal as modulated, and a CAS module, upon receiving a program identifier from the first broadcast processing module, for reading a key value from a certificate card corresponding to the program identifier and providing the key value to the first broadcast processing module; at least one host network connector having a first filter and a second filter, wherein the first filter for filtering STB control signal received from a specific network and providing the filtered STB control signal to the second broadcast processing module, and wherein the second filter for filtering the A/V remote broadcast signal received from the second broadcast processing module and passing the filtered A/V remote broadcast signal onto the network; at least one remocon signal receiver for sensing and outputting STB control signal transmitted from a wireless remocon; and at least one guest network connector having a third filter and a fourth filter, wherein the third filter for filtering the STB control signal received from the remocon signal receiver and passing the filtered STB control signal onto the network, and wherein the fourth filter for filtering and passing the A/V remote broadcast signal provided from the network. [12] For accomplishing the object, the multi-out broadcasting receiver system using
CAS of single set-top box according to a second embodiment of the present invention, comprising: a set-top box, which including, a first broadcast processing module, by a user operation, for selecting a channel of broadcast signal received from external transmission medium, a second broadcast processing module, upon receiving remocon control signal, for selecting a channel of the broadcast signal received from external tranmission medium, modulating A/V broadcast signal of the selected channel (hereinafter, "A/V remote broadcast signal") to a predetermined broadcast frequency, and outputting the A/V remote broadcast signal as modulated, and a CAS module, upon receiving a program identifier from the first broadcast processing module, for reading a key value from a certificate card corresponding to the program identifier and providing the key value to the first broadcast processing module; at least one remocon signal receiver for sensing STB control signal transmitted from a wireless remocon and outputting the sensed STB control signal onto a network; and at least one guest network connector having a fourth filter for filtering and passing the A/V remote broadcast signal provided from the network.
Advantageous Effects
[13] As described, according to the present invention, under connection between a set- top box and multiple of TV receivers each positioned in distant locations through a pre-installed network in a house or other specific location, the coexistence of remocon IR data and TV RF A/V signal in the RF line by adopting filter technology and the de- scrambling of more than two channels respectively scrambled using a single certificate card are enabled, so that a user may indepently watch multiple TV's in each of distant locations using a single set-top box and may remotely control the set-top box from a distant location where the set-top box is not positioned using a remocon. According to the invention, the multi-out broadcasting receiver system using CAS of a single set-top box is advantageous in that a user may independently watch multiple TV's in distant locations using only signal set-top box, in that only one certificate card is required, and in that cable engineering in each of distant location or expensive RF (UHF) remocon transmitter/receiver is not required.
[14]
Brief Description of the Drawings
[15] FIG. 1 is a functional block diagram illustrating a construction of the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention, [16] FIG. 2 is a functional block diagram illustrating a construction of the CAS module for the multi-out broadcasting receiver system using CAS of single STB shown in the
FIG. 1, [17] FIG. 3 is a functional block diagram illustrating a construction of the first broadcast processing module for the multi-out broadcasting receiver system using CAS of single
STB shown in the FIG. 1, [18] FIG. 4 is a functional block diagram illustrating a construction of the second broadcast processing module for the multi-out broadcasting receiver system using CAS of single STB shown in the FIG. 1, [19] FIG. 5 is a diagram illustrating broadcasting channel frequencies which are used as carrier frequencies in order to transmit via network broadcast signal for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention, [20] FIG. 6 is a diagram illustrating a procedure by which broadcast signal is transmitted using a specific broadcasting channel frequency for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention, [21] FIG. 7 is a diagram illustrating a procedure by which broadcast signal is transmitted using a intermediate frequency, which frequency is set for avoiding the broadcasting channel frequencies, for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention, [22] FIG. 8 is a diagram illustrating a procedure by which STB control signal transmitted using FSK (Frequency Shift Keying) modulation for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention, [23] FIG. 9 is a functional block diagram illustrating a construction of the multi-out broadcasting receiver system using CAS of single STB according to a second embodiment of the present invention, [24] FIG. 10 is a diagram illustrating a modified contraction of the multi-out broadcasting receiver system using CAS of single STB according to the present invention, where multiple of rooms are positioned in distant locations. [25]
Best Mode for Carrying Out the Invention [26] Hereinafter, the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention will be described in detail with reference to accompanying drawings. [27] FIG. 1 is a functional block diagram illustrating a construction of the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention,
[28] Hereinafter, detailed description about general prior art construction or functions regarding set- top box 100 shall be omitted in order to let the description of the specfication simple and clear.
[29] As shown in FIG. 1, the multi-out broadcasting receiver system using CAS of single
STB according to an embodiment of the present invention includes a set- top box 100 having CAS 101, a first broadcast processing module 110 and a second broadcast processing module 120, a host network connector 130, a remocon signal receiver 150, and a guest network connector 160.
[30] Alternatively, FIG. 10 is a diagram illustrating a modified contraction of the multi- out broadcasting receiver system using CAS of single STB according to the present invention, where multiple of rooms are positioned in distant locations, where a set-top box 100 having a CAS module 101, a first broadcast processing module 110 and at least one second broadcasting modules 120, at least one host network connectors 130, at least one remocon receivers 150, and at least one guest network connectors 160 are described. The host network connectors 130, as shown in FIG. 10, are as same provided as the number of the second broadcast processing modules 120 so as to establishing the one-to-one correspondence. Otherwise, only one set of host network connector 130 is provided so that the host network connector 130 mixes the signals from the broadcast processing modules 120 and outputs the mixed signal to the second filter 132 of the host network connector 130, and that the signal provided from the first filter 131 is respectively provided to each of the second broadcast processing modules 120.
[31] The multi-out broadcasting receiver system using CAS of single set- top box according to an embodiment of the present invention, without departing from the spirit of the present invention, may be similarily extended to be adapted to a case having two rooms as shown in FIGs. 1 to 9, or to a case having many rooms as shown in FIG. 10, which lets any repetitive descriptions regarding substantially same constuction be omitted.
[32] The CAS module 101, upon receiving a program identifier from the first broadcast processing module 110, reads a key value from a certificate card corresponding to the program identifier and provides the key value to the first broadcast processing module 110. As shown in FIG. 2, the CAS module 101 comprises a CAS controller 102 and a FIFO memory 103.
[33] FIG. 2 is a functional block diagram illustrating a construction of the CAS module for the multi-out broadcasting receiver system using CAS of single STB shown in the FIG. 1.
[34] The CAS controller 102 receives a program identifier from the first broadcast processing module 110 and stores the program identifier in the FIFO memory 103. The CAS controller 102 reads a key value from certificate card 104 corresponding to the program identifier which is priorly stored in the FIFO memory 103, and outputs the key value to the first broadcast processing module 110. The FIFO memory 103, responding to an external request, provides the priorly stored contents.
[35] The first broadcast processing module 110, following a user operation, selects a channel of broadcast signal received from external transmission medium, and outputs the selected channel of A/V broadcast signal. As shown in FIG. 3, the first broadcast processing module 110 comprises a broadcast signal receiver 111, MPEG decoder 112, A/V broadcast signal output 113, a first broadcast processing controller 114 and a de- scrambler 115.
[36] FIG. 3 is a functional block diagram illustrating a construction of the first broadcast processing module for the multi-out broadcasting receiver system using CAS of single STB shown in the FIG. 1.
[37] The broadcast signal receiver 111 receives the broadcast signal from external transmission medium, and outputs the digital broadcast signal, and the MPEG decoder 112 decodes the received broadcast signal and D/A converts the decoded signal.
[38] The A/V broadcast signal output 113 receives the broadcast signal from the MPEG decoder 112, modulates the received broadcast signal to A/V signal, and outputs the modulated signal to the first TV receiver 140.
[39] The first broadcast processing controller 114 retrieves a program identifier from the digital broadcast signal provided from the broadcast signal receiver 111, outputs the retrieved program identifier to the CAS module 101, and then is provided the key value from the CAS module 101. And, the first broadcast processing controller 114 receives the program identifier from the second broadcast processing module 120, outputs the program identifier to the CAS module 101, and then, upon receiving a key value for the program identifier from the CAS module 101, provides the received key value to the second broadcast processing module 120.
[40] The descrambler 115, upon receiving a key value from the first broadcast processing controller 114, receives the broadcast signal from the broadcast signal receiver 111 and descrambles the broadcast signal, and then outputs the descrambled signal to the MPEG decoder 112.
[41] Further, the second broadcast processing module 120, upon receiving the remote control signal, selects a channel for the broadcast signal received from external tranmission medium, and modulates the selected channel of A/V broadcast signal (hereinafter, "A/V remote broadcast signal") to a predetermined broadcast frequency. As shown in FIG. 4, the second broadcast processing module 120 comprises a broadcast signal receiver 121, MPEG decoder 122, broadcast signal modulater 123, an amplifier 124, a remocon signal retriever 125, a second broadcast processing controller 126 and a descrambler 127.
[42] FIG. 4 is a functional block diagram illustrating a construction of the second broadcast processing module for the multi-out broadcasting receiver system using CAS of single STB shown in the FIG. 1.
[43] The broadcast signal receiver 121 receives a broadcast signal from external transmission medium and outputs the received broadcast signal to the MPEG decoder 122. The MPEG decoder 122 decodes the received broadcast signal and D/ A converts the decoded signal.
[44] The broadcast signal modulater 123 receives the broadcast signal from the MPEG decoder 122, and modulates the broadcast signal to a predetermined broadcast frequency, and then outputs the modulated signal to the second filter 132. The remocon signal retriever 125 retrieves the remote control signal provided from the first filter 131, and then outputs the retrieved signal.
[45] The second broadcast processing controller 126 retrieves a program identifier from digital broadcast signal provided from the broadcast signal receiver 121, outputs the retrieved program identifier to the first broadcast processing module 110, receives key value from the first broadcast processing module 110, and then sets the broadcast channel of the broadcast signal receiver responding to the remote control signal provided from the remocon signal retriever 125. Further, the second broadcast processing controller 126 includes functions of, by remote control signal, system configuration, menu setup, PVR (Personal Video Recorder) control, EPG (Electronic Program Guide) control. As shown in FIG. 10, if multiple of second broadcast processing controllers 120 are connected as daisy chain, the second broadcast processing controller 125, upon receiving program identifier from a second module of the second broadcast processing module 120 which is far connected to said CAS module 101, outputs the program identifier to the first broadcast processing module 110 or a third module of the second broadcast processing module 120 which is near connected to the CAS module 101, and, upon receiving key value corresponding to the program identifier from the first broadcast processing module 110 or the third module of the second broadcast processing module 120, provides the key value to the second module of the second broadcast processing module 120.
[46] The descrambler 127, upon receiving the key value from the second broadcast processing controller 125, receives the broadcast signal from the broadcast signal receiver 121 and descrambles the broadcast signal, and then provides the descrambled signal to the MPEG decoder 122.
[47] Here, an amplifer 124 may be installed to the end of the broadcast signal modulater
123 in order to compensate loss in the A/V remote broadcast signal incurred due to cable line distance.
[48] The first broadcast processing module 110 and the at least one second broadcast processing module 120 may be implemented as one-chip or as separated chips.
[49] The host network connector 130 includes a first filter 131 and a second filter 132.
The first filter 131 filters STB control signal received from from a specific network 190, and provides the filtered STB control signal to the second broadcast processing module 120. The second filter 132 filters A/V remote broadcast signal received from the second broadcast processing module, and passes the filtered A/V remote broadcast signal onto the network 190.
[50] The remocon signal receiver 150 senses and outputs the STB control signal transmitted from a wireless remocon 180.
[51] The guest network connector 160 includes a third filter 161 and a fourth filter 162.
The third filter 161 filters the STB control signal received from the remocon signal receiver 150, and passes the filtered STB control signal onto the network 190. The fourth filter 162 filters and passes the A/V remote broadcast signal provided from the network 190.
[52] Generally, the first filter 131 and the third filter 161 are low pass filters (LPF) which covering bandwidth of remocon signal frequency range, and the second filter 132 and the fourth filter 162 are high pass filters (HPF) which covering bandwidth of VHF/UHF frequency range.
[53] The set-top box 100 may be constructed as one single set which includes the host network connector 130 having the first filter 131 and the second filter 132. The guest network connector 160 having the third filter 161 and the fourth filter 162 may be constructed as one single set which includes the remocon signal receiver 150.
[54] Further, the network 190 generally refers to a pre-installed TV coaxial cable or other post-installed network cable.
[55] Then, the operations of the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention will be described in detail with reference to FIGs. 1 and 2, wherein, with letting the host network connector 130 being positioned in a living room and the guest network connector 160 being positioned in other location (a main room or study rooms), the host network connector 130 and the guest network connector 160 is each connected via coaxial cables to RF terminals on the wall.
[56] A user inserts a certificate card 104 to a set-top box 100 so as to let the user certification by CAS module 101 is enabled.
[57] Firstly, the certification procedure is described for a user in the location where the set- top box 100 is positioned watches a program using the first TV receiver.
[58] The broadcast signal receiver 111 of the first broadcast processing module 110 receives the broadcast signal from external transmission medium, and outputs the digital broadcast signal of the channel which is selected by a user operation to the first broadcast processing controller 114 and the MPEG decoder 112. If the received broadcast signal is free from scrambling, the MPEG decoder 112 may decodes the broadcast signal and D/A converts the decoded signal. However, when the received broadcast signal is scrambled, the broadcast signal should be first descrambled using the key value for the program before MPEG decoding.
[59] For this purpose, the first broadcast processing controller 114 receives broadcast signal from the broadcast signal receiver 111, retrieves the program identifier from the broadcast signal, and provides the program identifier to the CAS module 101.
[60] Then, CAS module 101 stores the program identifier into FIFO memory 103 so as to process program identifiers by the order of receiving. The CAS module 101 reads proram identifier from FIFO memory 103, and searches a key value matching to the one stored in the certificate card. The certificate card stores multiple of key values for user certification for correspoding program. When a matching key value being found, CAS module 101 outputs the key value to the first broadcast processing controller 114, and the first broadcast processing controller 114 outputs the key value to the de- scrambler 115.
[61] The descrambler 115, upon receiving broadcast signal from the broadcast signal receiver 111, descrambles the received broadcast signal using the key value provided from the first broadcast processing controller 114. The broadcast signal, recovered as the original before scrambling, is provided to MPEG decoder 112, and the MPEG decoder 112 decodes the broadcast signal and D/A converts the decoded signal.
[62] Then, the A/V broadcast signal output 113 modulates the broadcast signal to A/V signal, and outputs the modulated signal to the first TV receiver 140. By this procedure, a user in the location where the set- top box 100 is positioned watches a program.
[63] Secondly, the certification procedure is described for a user in the location where the set- top box 100 is not positioned watches a program using the second TV receiver.
[64] When a user in distant location does a remote control using a wireless remocon 180, the remocon signal receiver 150 senses STB control signal transmitted from the wireless remocon 180 and outputs the sensed signal to the third filter 161 of the guest network connector 160, and then the third filter 161 of the guest network connector 160 filters the STB control signal and passes to the network 190.
[65] Then, the first filter 131 of the host network connector 130 receives and filters the
STB control signal, transmitted from the network 190 to the guest network connector 160, and outputs the filtered signal to the second broadcast processing module 120. The second broadcast processing module 120 receives the filtered signal (remote control signal) from the first filter 131 of the host network connector 130. Then, the second broadcast processing module 120, by the remote control signal, modulates the A/V remote broadcast signal received from external transmission medium, and then outputs the modulated signal to the second filter 132 of the host network connector 130. Here, during transforming the broadcast signal received from external transmission medium into the A/V remote broadcast signal, when the broadcast signal is scrambled, the procedure of user certification and descrambling of broadcast signal should be included. The user certification in the second broadcast processing module 120 is as follows.
[66] The broadcast receiver 121 of the second broadcast processing module 120 receives the broadcast signal received from external transmission medium and the received signal to the second broadcast processing controller 126 and MPEG decoder 122. If the received broadcast signal is not scrambled for access control, MPEG decoder 122 decodes the received broadcast signal and D/A converts the decoded signal. However, if the received broadcast signal is scrambled, MPEG decoding should be done after de- scrambling the broadcast signal using the key value of the corresponding program.
[67] For the purpose, the second broadcast processing controller 126 receives broadcast signal from the broadcast signal receiver 121, retrieves the program identifier from the broadcast signal, and provides the program identifier to the first broadcast processing module 110. Then, the first broadcast processing controller 114 receives program identifier from the second broadcast processing module 120 and outputs the received to the CAS module 101. The procedure for retrieving a key value corresponding to the program identifier from the certificate card 104 is same as described above. The first broadcast processing controller 114 receives the key value orresponding to the program identifier from the CAS module 101, and provides to the second broadcast processing module 120.
[68] As shown in FIG. 10, when multiple of second broadcast processing controllers 120 are connected as daisy chain, in order to provide a program identifier to CAS module 101, the program identifier should go through multiple of second broadcast processing modules 120 and the first broadcast processing modules 110. For implementation, the second broadcast processing controller 125 operates as follows. The second broadcast processing controller 125, upon receiving program identifier from a second module of the second broadcast processing module 120 which is far connected to said CAS module 101, outputs the program identifier to the first broadcast processing module 110 or a third module of the second broadcast processing module 120 which is near connected to the CAS module 101, and, upon receiving key value corresponding to the program identifier from the first broadcast processing module 110 or the third module of the second broadcast processing module 120, provides the key value to the second module of the second broadcast processing module 120. By this implementation, each second broadcast processing module 120 receives broadcast signal and retrieves program identifiers, and simultaneously behaves as a medium for carrying the program identifier and key value provided from other broadcast processing modules 110, 120.
[69] The second broadcast processing controller 126 of the second broadcast processing module 120 receives a key value corresponding to the program identifier of the program, and then outputs the key value to the descrambler 127.
[70] The descrambler 127, upon receiving the broadcast signal from the broadcast signal receiver 121, descrambles the broadcast signal using a key value which is received from the second broadcast processing controller 126. The broadcast signal, recovered to the original before the scrambling, is provided to the MPEG decoder 122, and the MPEG decoder 122 decodes the received broadcast signal and D/ A converts the decoded signal.
[71] By the procedure above, the user certification is accomplished in the second broadcast processing module 120, and then broadcast signal modulater 123 modulates the A/V remote broadcast signal to a predetermined broadcasting frequency and outputs the modulated signal to the second filter 132.
[72] The second filter 132 of the host network connector 130 receives and passes to the network 190 the A/V remote broadcast signal which is modulated through the second broadcast processing module 120. The fourth filter 162 of the guest network connector 160 receives and filters to pass the A/V remote broadcast signal. Then, the second TV receiver 170 receives the A/V remote broadcast signal and displayes a corresponding program to users.
[73] Generally, the first filter 131 and the third filter 161 are low pass filters (LPF) which covering bandwidth of remocon signal frequency range, and the second filter 132 and the fourth filter 162 are high pass filters (HPF) which covering bandwidth of VHF/UHF frequency range.
[74] FIG. 5 is a diagram illustrating broadcasting channel frequencies which are used as carrier frequencies in order to transmit via network broadcast signal for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention.
[75] As shown in FIG. 5, in order for the second broadcast processing module 120 to output onto the network 190, the broadcast signal modulater 123 modulates the A/V remote broadcast signal to a specific broadcasting channel frequency, and outputs the modulated signal. The procedure of using a specific broadcasting channel frequency shown in FIG. 5 as a carrier frequency is described in FIG. 6.
[76] FIG. 6 is a diagram illustrating a procedure by which broadcast signal is transmitted using a specific broadcasting channel frequency for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention.
[77] With referring to the example shown in FIG. 6, the broadcast signal modulater 123 modulates the A/V remote broadcast signal to 474 MHz which corresponds to channel 21, and outputs the modulated signal to the second filter 132. Then, the A/V remote broadcast signal, which is modulated to the frequency of 474 MHz, is carried via the network 190 to the fourth filter 162. The fourth filter 162, if configured to pass signal of 474 MHz out of signals received from the network 190, passes the A/V remote broadcast signal which has been modulated by the broadcast signal modulater 123 to 474 MHz as matching to channel 21. Therefore, the second TV receiver 170 may display the A/V broadcast signal which is transmitted as modulated by the broadcast signal modulater 123.
[78] Alternatively, the broadcast signal modulater may use an intermediate frequency avoiding the broadcasting channel frequencies as carrier frequency, which is conceptually described in FIG. 7.
[79] FIG. 7 is a diagram illustrating a procedure by which broadcast signal is transmitted using a intermediate frequency, which frequency is set for avoiding the broadcasting channel frequencies, for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention.
[80] When referring to the example shown in FIG. 7, the broadcast signal modulater 123 modulates the A/V remote broadcast signal to 478 MHz which corresponds to an intermediate frequency between channel 21 and channel 22 as shown in FIG. 5, and outputs the modulated signal to the second filter 132. Then, the A/V remote broadcast signal, which is modulated to the frequency of 478 MHz, is carried via the network 190 to the fourth filter 162. The fourth filter 162, if configured to pass signal of 478 MHz out of signals received from the network 190, passes the A/V remote broadcast signal which has been modulated by the broadcast signal modulater 123 to 478 MHz as matching to channel 21.
[81] Because the second TV receiver 170 is manufactured according to the prior art broadcasting channel frequencies, the signal should be changed to a signal corresponding to channel 21. Therefore, with positioning a modulating unit 165 between the fourth filter 162 and the second TV receiver 170, the modulating unit 165 re- modulates the A/V remote broadcast signal of 478 MHz which has passed out from the fourth filter 162 into the frequency of 474 MHz corresponding to channel 21. Therefore, the second TV receiver 170 may display the A/V broadcast signal which is transmitted as modulated by the broadcast signal modulater 123.
[82] FIG. 8 is a diagram illustrating a procedure by which STB control signal transmitted using FSK (Frequency Shift Keying) modulation for the multi-out broadcasting receiver system using CAS of single STB according to an embodiment of the present invention.
[83] The guest network connector 160 may be configured to FSK (Frequency Shift
Keying) modulate the STB control signal received from the remocon signal receiver 150. That is, by further including a FSK modulater 166 doing FSK modulation, the STB control signal is provided to the network 190 as FSK-modulated.
[84] Then, the host network connector 130 is provided a remote control signal as FSK- modulated. Then, after FSK demodulater 136 recovers the remote control signal as original by FSK demodulation, the recovered remote control signal is provided to remocon signal retriever 125 of the second broadcast processing module 120, by which transmission of the remote control signal is accomplished.
[85] FIG. 9 is a functional block diagram illustrating a construction of the multi-out broadcasting receiver system using CAS of single STB according to a second embodiment of the present invention,
[86] The embodiment shown in FIG. 1 includes all the filters, from the first filter 131 to the fourth filter 162. However, the second embodiment shown in FIG. 9 has the characteristics of optionally including filters other than the fourth filter 262.
[87] As shown in FIG. 9, the minimal construction of the multi-out broadcasting receiver system using CAS of single set-top box according to a second embodiment of the present invention comprises a set- top box 200 having a CAS module 201, a first broadcast processing module 210 and a second broadcast processing module 220, a remocon signal receiver 250 and a guest network connector 260.
[88] As shown in FIG. 10, the multi-out broadcasting receiver system using CAS of single set-top box according to a second embodiment of the present invention reflects a modified contraction, where multiple of rooms are positioned in distant locations, wherein a set- top box 200 having a CAS module 201, a first broadcast processing module 210 and at least one second broadcasting modules 220, at least one remocon receivers 250 and at least one guest network connectors 260 constitute a minimal construction.
[89] The multi-out broadcasting receiver system using CAS of single set-top box according to a second embodiment of the present invention, without departing from the spirit of the present invention, may be similarily extended to be adapted to a case having two rooms as shown in FIG. 9, or to a case having many rooms as shown in FIG. 10, which lets any repetitive descriptions regarding substantially same constuction be omitted.
[90] The CAS module 201, upon receiving a program identifier from the first broadcast processing module 210, reads a key value from a certificate card corresponding to the program identifier and provides the key value to the first broadcast processing module 210. The construction of CAS module 201 is same to the CAS module 101 for the first embodiment described above.
[91] The first broadcast processing module 210, following a user operation, selects a channel of broadcast signal received from external transmission medium, and outputs the selected channel of A/V broadcast signal. The first broadcast processing module 210 comprises a broadcast signal receiver, MPEG decoder, A/V broadcast signal output, a first broadcast processing controller and a descrambler.
[92] The broadcast signal receiver receives broadcast signal from external transmission medium, and outputs the digital broadcast signal to the MPEG decoder, and the MPEG decoder decodes the received broadcast signal and D/A converts the decoded signal.
[93] The A/V broadcast signal output receives the broadcast signal from the MPEG decoder, modulates the received broadcast signal to A/V signal, and outputs the modulated signal to the first TV receiver 240.
[94] The first broadcast processing controller retrieves a program identifier from the digital broadcast signal provided from the broadcast signal receiver, outputs the retrieved program identifier to the CAS module 201, and then is provided the key value from the CAS module 201. And, the first broadcast processing controller receives the program identifier from the second broadcast processing module 220, outputs the program identifier to the CAS module 201, and then, upon receiving a key value for the program identifier from the CAS module 201, provides the received key value to the second broadcast processing module 220.
[95] The descrambler, upon receiving a key value from the first broadcast processing controller, receives the broadcast signal from the broadcast signal receiver and de- scrambles the broadcast signal, and then outputs the descrambled signal to the MPEG decoder.
[96] Further, the second broadcast processing module 220, upon receiving the remote control signal, selects a channel for the broadcast signal received from external tranmission medium, and modulates the selected channel of A/V broadcast signal (hereinafter, "A/V remote broadcast signal") to a predetermined broadcast frequency. The second broadcast processing module 220 comprises a broadcast signal receiver, MPEG decoder, broadcast signal modulater, an amplifier, a remocon signal retriever, a second broadcast processing controller and a descrambler.
[97] The broadcast signal receiver receives a broadcast signal from external transmission medium and outputs the received broadcast signal to the MPEG decoder. The MPEG decoder decodes the received broadcast signal and D/A converts the decoded signal.
[98] The broadcast signal modulater receives the broadcast signal from the MPEG decoder, and modulates the broadcast signal to a predetermined broadcast frequency, and then outputs the modulated signal to the second filter 232. The remocon signal retriever retrieves the remote control signal provided from the first filter 231, and then outputs the retrieved signal.
[99] The second broadcast processing controller retrieves a program identifier from digital broadcast signal provided from the broadcast signal receiver, outputs the retrieved program identifier to the first broadcast processing module 210, receives key value from the first broadcast processing module 210, and then sets the broadcast channel of the broadcast signal receiver responding to the remote control signal provided from the remocon signal retriever. Further, the second broadcast processing controller includes functions of, by remote control signal, system configuration, menu setup, PVR (Personal Video Recorder) control, EPG (Electronic Program Guide) control. As shown in FIG. 10, if multiple of second broadcast processing controllers 220 are connected as daisy chain, the second broadcast processing controller, upon receiving program identifier from a second module of the second broadcast processing module 220 which is far connected to said CAS module 201, outputs the program identifier to the first broadcast processing module 210 or a third module of the second broadcast processing module 220 which is near connected to the CAS module 201, and, upon receiving key value corresponding to the program identifier from the first broadcast processing module 210 or the third module of the second broadcast processing module 220, provides the key value to the second module of the second broadcast processing module 220.
[100] The descrambler, upon receiving the key value from the second broadcast processing controller, receives the broadcast signal from the broadcast signal receiver and descrambles the broadcast signal, and then provides the descrambled signal to the MPEG decoder.
[101] Here, an amplifer may be installed to the end of the broadcast signal modulater in order to compensate loss in the A/V remote broadcast signal incurred due to cable line distance.
[102] The first broadcast processing module 210 and the at least one second broadcast processing module 220 may be implemented as one-chip or as separated chips.
[103] The remocon signal receiver 250 senses and outputs the STB control signal transmitted from a wireless remocon 280.
[104] The guest network connector 260 includes a fourth filter 262 for filtering and passing the A/V remote broadcast signal provided from the network 290. The fourth filter 262 is high pass filter (HPF) which covering bandwidth of VHF/UHF frequency range.
[105] The network 290 generally refers to a pre-installed TV coaxial cable or other post- installed network cable.
[106] The guest network connector 260 may further comprises a third filter 261 for filtering a STB control signal from the remocon signal receiver 250 so as to output the remote control signal onto the network 290. Other construction is similar to the embodiment shown in the FIG. 9. The third filter 261 is low pass filter (LPF) which covering bandwidth of remocon signal frequency range, and the fourth filter 262 is high pass filter (HPF) which covering bandwidth of VHF/UHF frequency range.
[107] And, at least one host network connectors 230 having a second filter 232 for, upon receiving A/V remote broadcast signal from the second broadcast processing module 220, filtering A/V remote broadcast signal so as to pass the filtered signal onto the network 290. Other construction is similar to the embodiment shown in the FIG. 9. The third filter 261 is low pass filter (LPF) which covering bandwidth of remocon signal frequency range, and the second filter 232 and the fourth filter 262 are high pass filters (HPF) which covering bandwidth of VHF/UHF frequency range.
[108] The host network connector 230 may further comprises a first filter 231 for filtering
STB control signal via the network 290 so as to provide the filtered STB control signal to the second broadcast processing module 220. Other construction is similar to the embodiment shown in the FIG. 9. The first filter 231 and the third filter 261 is low pass filter (LPF) which covering bandwidth of remocon signal frequency range, and the second filter 232 and the fourth filter 262 are high pass filters (HPF) which covering bandwidth of VHF/UHF frequency range.
[109] As for the multi-out broadcast receiving system using CAS of singla STB according to the second embodiment of the present invention, the A/V remote broadcast signal that is outputted from the broadcast signal modulator of the second broadcast processing module 220 may be set to an intermediate frquency for avoiding broadcasting channel frequencies, and the guest network connector further comprises a modulating unit for re-modulating intermediate frequency into a specific broadcasting channel frequency. Its operation is similar to the embodiment shown in FIG. 3, which lets repetitive descriptions be omitted.
[110] As for the multi-out broadcast receiving system using CAS of singla STB according to the second embodiment of the present invention, the guest network connector 260 may further comprises a FSK modulater for FSK (Frequency Shift Keying) modulating remote control signal upon receiving from the remocon signal receiver 250, and the host network connector 230 may further comprises a FSK demodulator for FSK demodulating the FSK-modulated remote control signal. Its operation is similar to the embodiment shown in FIG. 8, which lets repetitive descriptions be omitted.
[I l l] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.