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Description  |
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BACKGROUND OF THE INVENTION
The present invention relates to an interactive, chargeable communication system with a billing system for chargeable program which may be obtained by compressing video or audio information, a character information, data or application program
and transmitted from a multi-channel program communication service company, etc., through an interactive communication cable, ground wave, satellite wave or telephone line, etc., for the purpose of, for example, program request and home shopping, etc.
Particularly, the present invention relates to a chargeable broadcasting system in which a user receiving a scrambled program can watch and/or hear a program by descrambling the program by using a dedicated decoder while paying therefor based on
Pay-Per-View (PPV) system in which only program received by the user is billed.
Beside the conventional ground broadcasting in which a program video is transmitted to respective homes through the use of VHF or UHF wave, a cable broadcasting for directly transmitting program from a relay transmitter to respective home
terminals by using cables such as coaxial cables or optical cables extending therebetween is becoming popular and, particularly, a number of cable broadcasting enterprises are being established for providing multi-channel services owing to the fact that
transmission of programs using communication satellites or broadcasting satellites becomes possible recently.
Further, with developments of optical fiber technology, digital transmission technology and high efficiency coding technology, a communication service such as entertainment program delivery system, etc., which may substitute for the rental video
and in which a desired program is viewed at desired time by program request using interactive communication cable, such as home shopping or Video-On-Demand (VOD) program, have been studied.
Such cable broadcasting or VOD system transmits video signal through a coaxial cable, etc. Therefore, there is no radio fault such as ghost which occurs frequently in the program broadcasting using ground wave. Further, such system can be used
for a re-transmission of a usual program delivered by using ground wave and for broadcastings specific to program delivery companies.
Each viewer makes a contract with service companies of such as VOD and can view the re-transmission of program of the ground wave broadcasting supplied by cable broadcasting companies or service companies without radio fault by connecting a
dedicated receiving terminal to his video signal display device such as television receiver. Further, it becomes possible to view film drama, various sports relayed and music programs from such companies without using any special equipment other than
the dedicated terminal. Further, by connecting a video signal recording/reproducing apparatus such as VTR to the dedicated terminal, it is possible to record these programs.
On the other hand, the service company transmits program video software to only the viewers who made contract with it. Therefore, for the service company, it is desired to provide their programs to only viewers which made contract with it and
are chargeable. That is, any system according to which unauthorized viewers who did not make contract with a service company can view programs supplied by the company is not desired by the service company. In the conventional system, it is impossible
for any one having no dedicated terminal to directly receive programs from such service company and view them on a television receiver. However, when a program received by a dedicated terminal is copied by using, for example, a VTR, the copy can be
viewed easily by any one who has no dedicated terminal. That is, in the conventional system, it is impossible to prevent such unauthorized view of programs supplied from a service company.
In the BS standard scrambling system disclosed in, for example, K. Kobayashi, "1-2 Scrambled Broadcasting by BS", the Journal of Television Engineers Society, Vol. 46, No. 4. pp. 387 to 391 (1992), a content of program is scrambled and a viewer
who makes contract with a broadcasting company for each channel views it by descrambling the program by means of a dedicated decoder.
The billing in the disclosed system is based on the Flat-Fee system in which a constant viewing fee is charged for all programs. On the other hand, there is another billing system called Pay-Per-View (PPV) in which a viewer views only program he
wants to see and pays a fee for it. The PPV is classified to Pay-Per-Time (PPT) in which a viewer is charged for time for which he viewed the program and Pay-Per-Program (PPP) in which a viewer is charged for each program he viewed and the PPP is
sub-classified to Video-On-Demand (VOD) in which program data requested by each viewer is transmitted to him and Near-Video-On-Demand (NVOD) in which a viewer selects any of channels on which a single program is continuously broadcasted with broadcasting
time being shifted.
In a chargeable broadcasting using the PPP billing system, it may be considered that programs scrambled in any of a plurality of ways are broadcasted through a single channel and a viewer selects any of the programs, descrambles it and is charged
for the selected and descrambled program. In such case, it is enough for a broadcasting side to merely broadcast the respective scrambled programs in sequence. However, a viewer must reconfirm contents of the programs by temporarily stopping them and,
when he wants to view any or some of them, he must re-view the same program or programs by paying fee therefor or he must record data thereof on such as VTR while he is viewing it.
On the other hand, in CATV service, data is time-axis compressed and transmitted to each subscriber who stores the data in a digital recording device such as digital VTR (DVTR) and views it after decompression as in VOD. Since, in this case, it
is possible to reproduce the recorded digital data at any time repeatedly without degradation, there may be a problem of infringement of copyright of a producer of the program.
Therefore, in such chargeable broadcasting, a new billing system must be provided by taking the unauthorized recording of digital data and the unauthorized dubbing into consideration. This problem may be solved by detecting a descrambling
processing for a data received or reproduced from the DVTR and input to a decoder for descrambling and billing an owner of the decoder on the basis of the descrambling processing, since all views are billed and collection of fee is possible corresponding
to a state of viewing.
In this case, however, since the billing side can not determine program content reproduced from the VTR when a viewer views it by means of DVTR, the PPP billing system can not be applied thereto. In addition, when a special reproduction of a
program such as temporary stop, etc., in VTR, the same program is reproduced intermittently and therefore the number of views can not be determined clearly, causing determination of object to be billed to be difficult.
In view of these problems, it is effective to employ a billing system in which, for a program which is selected by a subscriber, the subscriber is given a permission of viewing the program for a time period measured in specific time unit, that
is, the subscriber is permitted to descramble the program for the time period and he is billed in program unit within the time period rather than the number of views, as in the current cassette rental system of video software. This system is disclosed
in, for example, Japanese Patent Application Laid-open (Kokai) No. H5-284499.
The interactive cable television in which an information, such as video or audio, character information or data, requested by a terminal connected to a network is scrambled by compressing it and transmitted to the terminal through the network is
disclosed in, for example, Y. Mochida, "Digital Optical Cable TV", the Journal of Television Engineers Society, Vol. 47, No. 8. pp. 1082 to 1087 (1993).
In the above article, although the technology concerned to the system and services of such interactive cable television is disclosed, there is no disclosure about the billing system for subscribers having such terminals and the copyright
protection.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an interactive, chargeable communication system including a billing system, by which the billing to subscribers can be done reliably while preventing infringement of copyright of video software.
Another object of the present invention is to provide an information compressing and transmitting apparatus which is capable of protecting copyright of an information which may be video or audio information, character information, data or
application programs, etc., and is transmitted and of billing subscribers having subscriber terminals receiving the information, by compressing the information according to a request or requests from a terminal or terminals connected to a network,
dividing the compressed information together with its attribute information to a plurality of information and transmitting the respective divided information according to a plurality of requests from the respective terminals connected to the network.
In order to achieve the above objects, according to an aspect of the present invention, there are provided, in a terminal of the subscriber for receiving program video signal delivered from a program service company, an error check circuit for
confirming an existence of transmission error in a communication route, a receiving monitor circuit for monitoring a program receiving condition such as program received and time of receiving in minute and a billing check circuit for checking a billing
to a subscriber by determining a receiving fee according to an error condition and the receiving condition monitored.
Further, the subscriber terminal is composed of a primary terminal portion for processing video signal received in order to prevent unauthorized reception of the video signal and a secondary terminal portion connected to the video signal display
device for displaying an actually received program on the monitor. The primary terminal portion includes a circuit for processing the received video signal to prevent unauthorized reception and a circuit for multiplexing an identification (ID) number,
etc., by which the subscriber terminal receiving a delivered program or the subscriber on the video signal. The secondary terminal portion includes a circuit for confirming an existence of a bill for the subscriber on the basis of the ID number
multiplexed in the primary terminal portion and a circuit for invalidating the unauthorized reception preventing processing performed in the primary terminal portion. The display device displays the program video after the confirmation is performed in
the ID number confirming circuit.
According to this system, after the program delivered by the service company is received, it is confirmed by the error check circuit of the primary terminal portion of the subscriber terminal whether or not there is a transmission error and then
the receiving time of the program in the primary terminal portion of the subscriber terminal and the kind, etc., of the program received are confirmed by the monitor circuit. On the basis of the error information and the program receiving information
obtained from these circuits, the billing system bills the subscriber.
The video signal is scrambled by the unauthorized reception preventing circuit in the primary terminal portion of the receiving terminal and multiplexed with an ID number which is preliminarily set in the respective terminals and with which a
specific terminal or subscriber can be specified and, then, output.
The video signal output from the primary terminal portion is supplied to the secondary terminal portion in which the ID number is separated. The billing state for that subscriber for the delivered program is confirmed by the ID number. That is,
an ID number with which a subscriber terminal can be identified is preliminarily set in a primary and a secondary terminal portions of the subscriber terminal, and, when the ID number of the primary terminal portion which is multiplexed with the video
signal in the primary terminal portion coincides with the ID number of the secondary terminal portion, it is judged that the subscriber having the terminal is billed. When it is confirmed that the secondary terminal portion is included in the terminal
of the subscriber who is billed, the program is descrambled and displayed on the video display device.
In this system, since the video signal output from the primary terminal portion is scrambled, the video signal can not be displayed correctly unless it is descrambled in the secondary terminal portion. Therefore, even if the video signal output
from the primary terminal portion is copied by using such as VTR and transferred to the third person, the latter can not view it on a monitor which is not connected to the secondary terminal portion. In other words, one who does not make contract with
the program supplier can not view any program supplied by them. Further, the video signal output from the primary terminal portion is displayed on a video display device after charge on a subscriber is confirmed. Therefore, even when a magnetic tape,
etc., on which a delivered program video is recorded by an authorized subscriber is transferred to another subscriber, the latter can not view the program since the video signal is not descrambled by other people than the authorized subscriber who has a
secondary terminal portion which is paired with the primary terminal portion which receives the program, that is, who does not pay fee for reception of the program.
As mentioned, according to this system, monitoring of the program by non-subscribers and subscribers who do not receive a program by themselves are prevented and thus it is possible to protect the program suppliers and copyright owners against
infringement.
In another aspect of the present invention, the objects can be achieved by transmitting from a transmitter side a video and audio data of a scrambled program together with a descrambling information and simultaneously transmitting a program ID
information different every program, separately or multiplexing on the data.
A decoder for descrambling the data comprises decoder means for detecting the descrambling information from the received data and decoding it, a descrambler for descrambling operation, program ID information processing means for storing program
ID information and comparing a program ID information of a program to be newly viewed with program ID information of programs which were viewed is the past and means for transmitting through a telephone line or a data line such as an up-link of an
interactive communication line to a billing side program ID information of program which was descrambled and viewed, under control based on a result of the comparison performed by the program ID information processing means.
Alternatively, the decoder may include only the program ID information decoding means and a transmitting means and all results of detection performed thereby are transmitted to the billing side which is provided with means which performs an
operation corresponding to that of the program ID information processing means.
When a user uses means such as DVTR for digitally recording a transmission data, the video and audio data before descrambling is recorded together with the descrambling information and the program ID information and, for reproducing them, the
scrambled data, the descrambling information and the program ID information are demodulated and reproduced in the same format as that for recording.
In any way, the transmitter multiplexes the descrambling information and the scrambled program ID information on the video and audio data at a specific period and transmits.
A viewer detects by means of the decoder means the descrambling information and the program ID information from the data received by the descrambling decoder, restores the processing pattern at a time when the data is scrambled, according to the
decoded descrambling information, and descrambles it by performing an inverse processing to the scrambling processing by the descrambler. The program ID information detected is compared with all programs which were viewed in a specific time and are
stored in the program ID information processing means to see whether or not there is a program ID information coincident with the detected program ID information. If there is no coincidence detected, it is deemed as reception of a new program and the
program ID information thereof is transmitted to the billing side and simultaneously it is stored in the program ID information processing means. The billing side gets a title of the program which is viewed by the subscriber from the received
information and bills the subscriber correspondingly. On the other hand, when there is a coincidence, it is deemed as a re-viewing of a program within a specific time and the program ID information thereof is neither stored nor transmitted.
In a case where the data is recorded by the digital recording means such as DVTR and viewed by reproducing it, the scrambled data, the descrambling information and the program ID information are recorded simultaneously and the respective signals
are simultaneously demodulated and reproduced in the same signal format as that in the recording time and they are supplied to the decoder in which they are processed usually.
Thus, the billing for viewing a scrambled program can be efficiently performed in program unit.
In another aspect of the present invention, the objects are achieved by an information compressing/transmitting apparatus comprising compression means for compressing data including such as video, audio, character information and application
program, first memory means for storing the compressed data, second memory means for storing attribute information necessary for decompressing the compressed data and other management information, means for attaching a common identifying information to
respective divided information, transmitting/receiving means for receiving requests from a plurality of terminals connected to a circuit and transmitting data stored in the first and second memory means according to a plurality of requests from the
terminal and a receiving/transmitting control means.
The information compressing/transmitting apparatus compresses the video, audio, character information, data and application program according to the requests from the terminals connected to the network, resulting in a compressed data and an
attribute information necessary for decompressing the compressed data. The compressed data is stored in the first memory and the attribute information is stored in the second memory together with other subscriber management information.
Upon a first and second information transmission requests from the terminals connected to the network, the data stored in the first and second memories are transmitted.
In general, the data stored in the first memory has a large amount of information and it takes a considerable time to transmit all of them by using the network. On the other hand, an amount data stored in the second memory is small and it can be
transmitted within a very short time which may be ignored by the terminal subscriber.
According to this aspect, an information requested by a subscriber is compressed and then divided to a plurality of pieces to which a common ID information is attached, respectively. The compressed information pieces with the common ID
information are transmitted. Thus, a copyright of the information can be protected and, when the first data of the information requested by the terminal subscriber is preliminarily received and stored, it is possible to receive the second data within
the very short time and to reproduce the requested data. The billing for the subscriber can be done according to the number of requests of the second data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A and FIG. 1B are a block diagram of a video signal receiving terminal according to a first embodiment of the present invention;
FIG. 2 shows an example of a data structure of a video signal transmitted from a program repeater in the first embodiment;
FIG. 3 shows an example of a data structure of a video signal transmitted between a primary and secondary terminal portions in the first embodiment;
FIG. 4 is a block diagram of a primary terminal portion according to a second embodiment of the present invention;
FIG. 5 is a block diagram of a secondary terminal portion according to a third embodiment of the present invention;
FIG. 6 shows an interactive communication network;
FIG. 7 is a block diagram of a video signal receiving terminal according to a fourth embodiment of the present invention;
FIG. 8 is a block diagram showing a fifth embodiment of the present invention;
FIG. 9 is a block circuit diagram of a portion of the embodiment shown in FIG. 8;
FIG. 10 is a block constructive diagram of an information transmitter of the interactive communication broadcasting system according to a sixth embodiment of the present invention;
FIG. 11 shows a data format to be used in a communication between the information transmitter and subscriber terminals;
FIG. 12 is a block diagram of an internal construction of the information compressing/transmitting apparatus shown in FIG. 10; and
FIG. 13 is a block diagram of an internal construction of another embodiment of the information compressing/transmitting apparatus shown in FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will be described with reference to FIGS. 1A to 3.
FIG. 1A and FIG. 1B are a block diagram of a video signal receiving terminal according to the first embodiment of the present invention when applied to display a program video transmitted through a wire broadcasting. The video signal receiving
terminal, that is, a subscriber terminal, includes a primary terminal portion 100 shown in FIG. 1A and a secondary terminal portion 150 shown in FIG. 1B.
Before describing the subscriber terminal shown in FIG. 1A and FIG. 1B, a cable broadcasting system will be described in brief with reference to FIG. 6. In FIG. 6, the system includes a program supplying company 600 which produces a chargeable
program and delivers it, a communication satellite (or broadcasting satellite) 610, a wire broadcasting relay transmitter 620, a communication cable 630 such as coaxial cable or optical cable which directly connected the relay transmitter to subscriber
terminals 641, 642 and 643 and at least one terminal 644 of a banking system.
In the cable broadcasting system, the program produced by the program supplier 600 is transmitted through the communication satellite 610 or through ground wave to the relay transmitter 620. In the relay transmitter 620, the program signal
transmitted from the program supplier 600 is received by using a large scale, high sensitivity antenna with signal degradation due to electromagnetic wave fault, etc., being minimized. The relay transmitter 620 transmits the received video signal
through the cable 630 which may be a public digital communication line, such as Integrated Service Digital Network (IDSN) which is used concomitantly with other communications such as telephone line, facsimile line and a computer or a communication line
dedicated to such as Cable Television (CATV), to the cable broadcasting receiving terminals 641 to 643 shown in FIG. 1A and FIG. 1B.
FIG. 2 shows an example of the data construction of the video signal transmitted from the relay transmitter to the respective subscriber terminals. In FIG. 2, the digital transmission data from the relay transmitter includes a data header
portion 200 including key signals, etc., necessary to decoding a program information having various information of the program transmitted and the compressed video data, compressed video data portions 211 and 212, etc., and parity check portions 221 and
222, etc., inserted into the compressed data portion for detecting any error and confirming whether or not video signals were correctly received by the destination terminals.
In this embodiment, the digital data is constituted with the data header portion 200 of n bytes, the compressed video data portions 211, 212, . . . each of m bytes and the parity portions 221, 223, . . . each of l bytes where n is a natural
number from several to ten and several, m is a natural number from several hundreds to several thousands and l is a natural number of several. The data header portion 200 is transmitted first in time, and, subsequent thereto, the compressed data
portions 211, 212, 213, . . . and the parity portions 221, 222, . . . are transmitted alternately until an end of the program. That is, it is transmitted in the sequence of 211, 221, 212, 222, . . . . Considering a receiving of the program on the way
thereof, the data header portion 200 should be inserted into not only the head of the data but also a plurality of locations, preferably, every specific time.
Returning to FIG. 1A and FIG. 1B, the primary terminal portion 100 for receiving a program transmitted from the relay transmitter 620 includes an input terminal 101 for receiving the video signal from the relay transmitter 620, a billing
information output terminal 102 for outputting a billing information for the reception of the program at the primary terminal portion 100, a video signal output terminal 103 for outputting a video signal scrambled in the primary terminal portion 100, a
demodulator circuit 111 connected to the input terminal 101 for digitally demodulating the video signal input, a separation circuit 112 connected to an output of the demodulator circuit 111 for separating, from the digitally demodulated video signal from
the demodulator circuit 111, the header portion 200 including a key signal necessary to decode the data header from the compressed video data and the parity portions, an error checker 113 for checking the compressed video data and the parity portion
confirming whether or not the video signal transmitted from the relay transmitter is received correctly, a billing check circuit 114 for producing a billing information for the program reception fee on the basis of the program information separated by
the separator circuit 112 and a result of the error check performed by the error checker 113, a memory 115 for storing an identification (ID) code specific to the primary terminal portion 100, a scrambler 116 for scrambling the decode key signal
separated by the separator circuit 112 by multiplexing the key signal and a terminal ID code stored in the memory 115 and a multiplexer circuit 117 for time-axis multiplexing the compressed video data output from the error checker 113 with the key
information scrambled by the scrambler 116.
The secondary terminal portion 150 shown in FIG. 1B includes an input terminal 151 connected to the video signal output terminal 103 of the primary terminal portion 100 for receiving the video signal scrambled therein, an extraction circuit 161
connected to the input terminal 151 for extracting the scrambled key information from the input video signal, a descrambler 162 for descrambling the key information extracted by the extraction circuit 161 and separating therefrom the decoding key and the
terminal ID code specific to the primary terminal portion 100, a memory 163 for storing the terminal ID code of the primary terminal portion 100, a comparator 164 for comparing the terminal ID code of the primary terminal portion 100 separated in the
descrambler 162 with the terminal ID code stored in the memory 163, a switch 165 for receiving a decode key output from the descrambler 162 and allowing the decoded key to pass therethrough according to an output of the comparator 164, a decode circuit
166 for decoding the compressed video signal by using the decode key passed through the switch 165, a D/A converter 167 for converting the decoded digital video signal from the decoder 166 into an analog signal and a monitor 168 for displaying the
program video which is thus converted into the analog signal.
In this embodiment, the error check is performed by using the Cyclic Redundancy Check (CRC) code in each of the parity portions 221 and 222, etc., shown in FIG. 2. That is, in the relay transmitter, a compressed video data is processed by using
special arithmetic operations, before the relay transmitter 620 transmits the video data, and an error detection code obtained thereby is attached to the compressed video data as a parity and, then, transmitted. In the receiving terminal side, that is,
in the primary terminal portion 100, the received compressed video data is processed according to the same arithmetic operations and a result thereof is compared with the parity. If the result of the arithmetic operations is equal to the parity, it is
determined that the compressed video data is correctly transmitted and received. The error checking code to be used in the error checker 113 is not limited to the CRC code. The Reed-Solomon code, the simple parity code or the Bose-Chaudhuri-Hocquenghem
(BCH) code, etc., may be used therefor as well. By using such error correction code, a transmission error may be corrected depending upon the degree of error.
The result of error check using the CRC code, etc., output from the error checker 113 is input to the billing check circuit 114 together with the program information from the separation circuit 112. In the billing check circuit 114, a billing
information for the subscriber is produced according to the error information from the error checker 113 and the program information attached to the received video signal. For example, when the program information is provided with the genre of program,
the name of production company and the name of copyright owner, etc., it is possible to change the receiving fee according to the genre of the program, news or movie, and, in the VOD service, to make collection of receiving fee for the production company
and/or the copyright owner or the service fee smooth. On the other hand, it is possible to reduce or even cancel the bill for the subscriber when the reception of the program is difficult due to transmission error which can be determined by using the
error information. For example, when there is a transmission error, the subscriber terminal can transmit the error information to the relay transmitter 620 and request a re-transmission of a video signal corresponding to the error portion. It should be
noted that the error checker 113 may be omitted if the communication route is error-free.
The billing information produced in the billing check circuit 114 is transmitted from the billing information output terminal 102 through telephone line or other lines or cables dedicated thereto to the relay transmitter 620 or the cable
broadcasting company. Further, when the cable connected to the input terminal 101 of the primary terminal portion 100 for receiving the video signal is an interactive cable, it can be used for transmitting the billing information as well. In such case,
the input terminal 101 is replaced by an input/output terminal and the billing information from the billing check circuit 114 is output through the input/output terminal. In such case, it is possible to not only reduce the number of communication cables
connecting between the relay transmitter 620 and the respective subscriber terminals but also facilitate adaptation to the interactive communication service such as the program request in the VOD system. Further, it becomes possible to perform a precise
research of view rate by performing the checking of program reception.
The key signal supplied from the separation circuit 112 to the scrambler 116 is scrambled and multiplexed with the terminal ID code specific to the primary terminal portion 100 and stored in the memory 115 as mentioned previously. The terminal
ID code may be, for example, a binary number. In this case, it is preferable to assign different binary numbers to the respective subscriber terminals. However, it is possible to substantially prevent duplication of terminal ID number by using a binary
number of 10 to 20 bits.
The key information which is scrambled in the scrambler 116 and multiplexed with the terminal ID code is input to the multiplexer circuit 117, together with the compressed video data, in which the key information and the compressed video data are
time-axis multiplexed and output from the output terminal 103.
FIG. 3 shows an example of a simple construction of the signal obtained by time-axis multiplex of the key information and the compressed video data. In FIG. 3, 301 depicts the key information and 311, 312 and 313, etc., depict the compressed
video data. In the construction shown in FIG. 3, the key information 301 is inserted every constant time, for example, at least once per 5 minutes, taking into consideration the fact that the information are recorded on a recording medium such as VTR
and may be reproduced from any point on the magnetic tape. In such case, when the reproduction of the magnetic tape is started on the compressed video data 312 subsequent to the key 301, the video data 312 can not be decoded since there is no key
information thereof. However, it is possible to decode the video data from the compressed video data 313 with using the subsequent key 301. When the recording/reproducing apparatus to be used is a randomly accessible apparatus such as laser disc,
optomagnetic disc or hard disc, etc., it is possible to reproduce a recorded program at any point of the program with the key information 301 located in only one point. However, since, in such case, there may be an error produced on the recording
medium, it is preferable to locate the key information 301 at at least two points.
The signal which is the compressed video data multiplexed with the key information and supplied from the output terminal 103 of the primary termi | | |
