Note: Descriptions are shown in the official language in which they were submitted.
CA 02338313 2001-O1-19
Delivery of Requested Video Sequences by Satellite
The invention designates the delivery of requested video
sequences by satellite, and in particular of music video
clips, with professional picture quality to receivers for
primary usage in authorized discotheques. In doing this,
the protection against unauthorized reproduction and usage
is to be maintained in particular.
In the international patent classification (IPC), the elec-
trical transmission of communications is assigned to class
H04B. Radio distribution systems, as such, are included in
class H04H 1/00 and those over satellite are specially in-
cluded in H04B 7/185. Picture transmission is assigned to
class H04N and for color television systems specially to
H04N 11/00, and for high-definition television (HDTV) to
H04N 11/24. Two-way operation, during which the receiver
sends a program selection signal, is in H04 7/173. The
transmission of digital ini=ormation is assigned to class
H04L and the special instructions for secure-access trans-
mission of communications are included in class H04L 9/00,
special means for determination of authorization to receive
in H04L 9/32 and for block coding and decoding of informa-
tion to H04L 9/06.
Video sequences, and in particular music video clips, are
subject, as a rule, to cod>yright protection, which espe-
cially forbids unauthorized r_ep.roduction. When such video
sequences are distributed, it must therefore be assured
that unauthorized further reproduction is not supported,
,.which, for example, is achieved through measures to protect
against copying.
For example, it is known from publication DE4418191 that
corresponding digitalized video pictures can be transmitted
CA 02338313 2001-O1-19
2
over telephone lines. T he disadvantage of this type of pro-
cedure is the quality loss due to the limited bandwidth of
the transmission path and the limited picture resolution.
In addition, due to the required point-to-point connection,
no concurrent delivery to multipl_c receivers is possible.
At the present time, moving pictures experts group (MPEG),
which defines a set with standards for the compression of
audio and video data, is normally used for the digital
transmission of video and/or storage. MPEG is also the ab-
breviation for a video or audio file in the MPEG format.
For differing applications and quality requirements for
video information, various types of compression have been
set. MPEG-1 defines, as the original MPEG standard for the
storage and the requesting of video and audio information,
which was developed for the CD-ROM technology, a medium
bandwidth of up to 1.5 Mbps, two audio channels and video
without interlaced scanning. MPEG-2 defines, as an expan-
sion of the MPEG-I standard, which was developed for the
compression of high-quality video signals and for televi-
sion transmission for HDTV, a broader bandwidth of up to 40
Mbps, five audio channels, a broader spectrum of picture
sizes and video with interlaced scanning. A fast crypto-
graphic algorithm, which was specially optimized for MPEG-
2, is described, which allows encoding and decoding and the
examination of the complete data stream.
The publication DE19643672 reveals a procedure for the de-
coding of a video bit stream according to the MPEG stan-
dard, which successively buffers an I-picture and a P-
~~ picture. To do this, the vs.deo bit stream must be continu
ally available during the entire time period with the re
quired bandwidth, meaning available as live data.
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3
ADR radio programs (ASTRA digital radio) allow the trans-
mission of digital data by satellite. The European Satel-
lite Multimedia Services S.A. allows its service - based on
a continuous data stream of broad bandwidth -, ASTRA-NET,
to provide digital video broadcasting (DVB) according to
the MPEG-2 standard. In addition, package-switched trans-
mission of digital data is supported, corresponding to the
Internet protocol, for discontinuous data transmission with
a narrow bandwidth. The standards for the package transmis-
sion in networks are documented in the CCITT-
Recommendation, X.25.
The publication DE29800778 reveals an arrangement for the
transmission of digital data in MPEG format over a satel-
lite within the framework of an ADR radio program, during
which a satellite receiver is directly assigned, after
phase shift keying (PSK) demodulation, a MPEG decoder,
which provides the continually transmitted video sequence.
The disadvantage of this sol.ut:ion is the necessity for live
data and a continuous broadband transmission.
The publication DE29603829 reveals an interactive transmis-
sion and playback of video files in MPEG format, where upon
request a remote data transmission path between a file
server and a playback computer is established, which is
equipped with a playback device for a MPEG file. The disad-
vantage of this is, that mu:Ltiple receivers can not receive
the transmitted video file at the same time. The lack of
security concerning unauthorized reproduction is also a
disadvantage.
A system for fast data transmission by means of telephone
and satellite transmission in a worldwide data network is
described in the publication WO 97/20413. To accomplish
this, data packets are formed in conformation to the net-
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4
work protocol with the receiver address, from information,
which was requested by a number of receivers over a net-
work, primarily Internet. from the data packets, a digital
data stream (MPEG-coded) i:~ generated using a multiplex
process and sent to numerous receivers by satellite,
whereby for the individual receiver only that part is in-
terpreted, which agrees with his address. The data trans-
mitted can also be encoded specifically for each receiver
and the receiver only decodes the data intended for him.
A system, which is similar in principle, is also described
in the publication W097/50250. For a near video-on-demand
system, a pool of program material is maintained, which is
transmitted by satellite in an encoded form to a number of
receivers. The headers of the transmissions contain infor-
mation, by means of which individually interesting programs
can be selected manually or with the help of self-learning
software and deposited in a mass storage device.
Both systems lack security against unauthorized reproduc-
tion and usage of data, which is addressed and transmitted
to the particular receiver, after its receipt and, under
circumstances, after it has been stored.
The purpose of the invention is the simple implementation
of a secure delivery of the requested video sequences with
a professional quality to individual authorized receivers
with low loading of the transmission path and thus low
transmission costs.
The problem is solved with the characteristics listed in
patent claim 1. Priority for further developments results
from the subordinate claims.
CA 02338313 2001-O1-19
The essence of the invention consists of the delivery of
requested video sequences - by means of the MPEG-2 stan-
dard, which was specially developed for the compression of
high-quality video signals to insure professional picture
5 quality - to a receiver, authorized through his receiver-
specific identification, as an MPEG-2 file based on the
insertion of satellite-supported package-switched data
transmission.
An additional essential aspect is the implementation of
real-time decoding of this MPEG-2 file, which can only be
done by the authorized receiver. This is done with the en
coding and decoding of the MPEG-2 file by means of a key,
which is specific to the video service provider, in real
time without having to store unencoded video sequences. For
the advantageous execution of this, the special crypto-
graphic algorithm, which is used for the encoding and de-
coding and examination of the complete data stream de-
scribed in the MPEG-2 standard, is used for real-time de-
coding.
It could be possible to transmit the requested video se-
quences coupled with commercials.
In addition, it is possible to automatically assign dynamic
commercials, according to instructions from the video serv-
ice provider and dependent on the length of the program, to
a program of video sequences, which is individually com-
posed by the receiver, for playback.
The advantages of the invention consist, in particular, of
the possibility of:
after viewing the contents of the video sequences, which
:were transmitted advantageously over the network in MPEG-1
format to the computer for previewing, making an individual
CA 02338313 2001-O1-19
~)
selection of the video sequences and ordering these indi-
vidually.
~ providing the requested video sequences over an economi
cal transmission path to the receiver with the highest
quality.
~ being able to allow multiple receivers to receive the
video sequences at the same time over the direct broadcast
connection.
~ maintaining these video sequences freely available at the
receiver's location, which would allow the receiver to pre
pare his own program.
~ an individual playback o1= t=he video sequences.
~ excluding unauthorized reproduction and use of the video
sequences.
~ dynamic and automatic assignment and playback of commer-
cials per program composition.
The invention will be explained in more detail as an exam-
ple of application based on figure 1 as instructions for
the delivery of video sequences.
According to figure l, a data connection exists between a
computer (1) of a receiver and a video service provider (2)
over a network (3) , such as the Internet, and through this
connection the receiver, who is authorized through a re-
ceiver-specific identification (4), selects and orders from
the products of the video service provider (2) individual
video sequences (5), such as music video clips, advanta-
geously after viewing the contents of the video sequences,
which were transmitted for preview over the network (3) in
MPEG-1 standard to the computer (1). At the conclusion of
the ordering process, the free storage of computer (1) of
the receiver is examined advantageously and the required
storage space for the receipt of the video sequence (5) is
CA 02338313 2001-O1-19
7
reserved. If the storage capacity is too low, then normal
procedures for the release of the lacking storage capacity
are to be carried out. The video service provider (2), who
collects the individual requests of various receivers and
S primarily groups them suitably, provides the video se-
quences (5) - optionally over a broadband connection (6)
with required bandwidth for transmission as MPEG-2 - in the
form of a MPEG-2 file ( 7 ) t;o a satellite transmitter ( 8 ) ,
which divides the video sequence (5) into individual pack-
ets (9) with the data (10), which are parts of the MPEG-2
file (7) , and header information (11) and - primarily se-
cured through transmission encoding with data encryption
standard ( DES ) 56BIT - transmit=s by means of an intermedi-
ate satellite (12), among other things, to a satellite re-
ceiver (13), which is connected to computer (1), which
stores the data (10) in a storage unit (14). In doing this,
the satellite receiver (13) insures, using the header in-
formation (11) and the receiver-specific identification (4)
of the computer (1), that only computer (1), for which the
data (10) are meant, stores the data (10) in the storage
unit (14). Following successful transmission, storage and
the connection of the data (10) of all packets (9), then
the MPEG-2 file (7) is available in the storage unit (14).
In order to guarantee protection against unauthorized re-
production, the MPEG-2 file (7) contains the video sequence
(5) in an encoded form. The playback of the video sequence
( 5 ) from the MPEG-2 file ( 7 ) by means of a MPEG-2 decoder
(15), assigned to computer (1), is thus only possible using
playback software (16), which is specific for the video
service provider, and which, using the temporary storage in
. computer (1) and the MPEG-2 decoder (15), deciphers and de
codes the video sequence (5) in real-time and then outputs
this as a video signal (18) without storing the unencoded
video sequences (5). Since the video sequence (5) is only
available in real-time as a video signal (18) at the output
CA 02338313 2001-O1-19
of the MPEG-2 decoder (15), an unauthorized reproduction
and use of this is not supported. The key (17), which is
required for the decoding of video sequence (5), is primar-
ily integrated as an updateable part in the video-service-
provider-specific playback software (16) and this key is
primarily the same for all authorized receivers. It is ad-
vantageous to use the fast cryptographic algorithm for de-
coding, which is optimized in the MPEG-2 standard for the
encoding and examination of the complete data stream, for
example, the algorithm u:~ed for the digital video disk
(DVD) .
It is, however, imaginable and also in the sense of the in-
vention, to use a public key procedure for the encoding and
decoding, whereby the key (17) required for the real-time
decoding of the video sequence (5) can only be calculated
from the receiver-specific identification (4) and is avail-
able exclusively only temporarily. It is also advanta-
geously imaginable to specify the MPEG-2 decoder (15) so
that, with respect to the monitor signal of computer (1), a
decoupling of the output of the video sequence (5) as the
video signal (18) is possible, which would allow the play-
back of video sequence (5) as video signal (18) as a type
of background application. It is also imaginable that a
graphic could be placed at the video output of the MPEG-2
decoder (15) and at the same time to continue working on
the monitor of computer (1) in a program.
A particularly advantageous application consists of the in-
tegration of the satellite receiver (13) with the computer
~. (1), the storage unit (14), the MPEG-2 decoder (15) and the
video-service-provider specific playback software (16) in a
set-top boy (19) with a modem/ISDN power supply. This will
allow, in addition to interactive television and TV shop
CA 02338313 2001-O1-19
9
ping, the individual receipt of video sequences (5) and the
playback of these.
The possibility of the coupling of video sequences (5) with
commercials is particularly interesting for the commercial
area. A video service provider (2) functions, in this re-
spect, at the same time as a commercial provider and as-
signs a number of commercials to the requested video se-
quences (5), which were composed for various receivers, but
a separate transmission of commercials is also possible.
The transmission, storage and playback are done principally
under the same conditions as for the video sequences (5).
The receiver can select freely from the video sequences (5)
stored in the storage unit (14) and individually compose a
program from these. This program is dynamically assigned a
certain number of commercials for a time unit, which is set
by the video service provider-, and which can not be influ-
enced by the receiver. The playback occurs at irregular in-
tervals, for example, between music video clips.
CA 02338313 2001-O1-19
Reference Symbols Used
1 Computer
2 Video service provider
3 Network
5 4 Receiver-specific identification
5 Video sequence
6 Broadband connection
7 MPEG-2 file
8 Satellite transmitter
10 9 Packet
10 Data
11 Header information
12 Satellite
13 Satellite receiver
14 Storage unit
15 MPEG-2 decoder
16 Video-service-provider-specific playback software
17 Key
18 Video signal
19 Set-top box
