Note: Descriptions are shown in the official language in which they were submitted.
2I 64300
~09S/Ol~ PCT~S94/0~8
INTERACTIVE COMMUNICATIONS SYSTEM WITH DATA DISTRIBUTION
BACRGROUND OF THE lNv~ oN
This application is a continuation-in-part of United
States patent application Serial No. 08/070,814, filed June
3, 1993, entitled INTERACTIVE VIDEO SYSTEM WITH DOCUMENT
DISTRIBUTION; and also a continuation-in-part of United
States patent application Serial No. 08/158,293, filed
November 29, 1993, entitled INTERACTIVE VIDEO COMMUNICATIONS
SYSTEM WITH DATA DISTRIBUTION.
The present invention relates to software and hardware
for the complete support of interactive video programming in
an environment which also supports the remote generation of
hard copy documents, and high capacity, efficient movement of
data in object form.
More particularly, the present invention is adapted
toward a distributed interactive television communications
method and system that supports distribution of audio /
visual information and data over existing television
distribution pathways.
The invention includes a specialized tuner and control
computer or receiver unit positioned adjacent to the user's
television to: (i) receive and decode digital and analog
signals, and thereby serve as an access point for pay per
view television programming; (ii) generate computer graphics
and multimedia signals for display; (iii) accept user input
through a graphical user interface for display; (iv) encode
and transmit user generated command sequences and user inputs
including credit card data; (v) print coupons and other hard
copy o~L~Ls; and (vi) execute computer software for service
as an integrated home data processing center.
The invention provides for a video and data transmission
system which transmits digital commands, and data in a novel
information format on existing television distribution
pathways and which utilizes advanced compression and
sequencing to efficiently distribute such data to many
receivers simultaneously. The information format is usable
on a plurality of ~roadcast bands and modalities.
Additionally, virtual channel maps can be used to control the
mapping of television programming and would be transmitted to
WO 95101060 , PCr/USg4106408
216~300
receiver units. The receiver units are adapted to
selectively extract information from a cont-inuous broadcast
stream as needed.
The receiver units are adapted to receive digitally
S encoded and possibly encrypted television signals that are
compressed and multiplexed with other like television
signals. Any number of independent receiver units can select
the same or different portions of the broadcast information
simultaneously. In this way, interactive integrated receiver
tuners with relatively small memory capacities and limited
processing capabilities can utilize data transmitted from a
large central data base at very low cost utilizing existing
television distribution networks, in addition to emerging
distribution technologies like Direct Broadcast Satellite
(DBS), and fiber optics.
Over the last twenty years, the popularity of television
programs which require users to contact the broadcaster
through conventional telephone lines speaks to the growing
demand for interactive television applications.
Advertisers appreciate the marketing power of immediate
response television sales programs which offer the
opportunity to reach mass numbers of consumers and close
actual sales with these customers on a real time basis.
Reports of sales in excess of one million dollars of
merchandise per hour have been reported with respect to shop-
at-home programs. However, these systems suffer from the
inability of a consumer to respond easily and efficiently.
Contact must often be made through the intervention of a
human operator who guides inexperienced users through the
shop-at-home process. Credit card information is revealed
over the telephone to salespeople who then have the
opportunity to misuse that information. In addition, such
systems suffer from an inability to offer written coupons or
other sales inducements to the customer. All of these
factors combine to lower overall margins and reduce
profitability of interactive television marketing in general.
In addition, the invention offers a unique pathway for
the distribution of data. Existing cable television lines,
VO95/01~ 2 164 30 ~ PCT~S94/0~8
for example, provide a broad bandwidth pathway for the
distribution of data. Terrestrial transmission in the UHF
band is an attractive pathway for the transmission of digital
television and data signaling. DBS and microwave link
5 television networks also provide attractive data pathways.
With the advent of digital television signals moving over
these pathways, significant bandwidth is being released for
additional uses by broadcasters. Where one 6 MHz analog
channel previously carried only the video and audio for one
television station, the new digital channels will carry four
to six such stations in the same 6 MHz frequency bandwidth.
Thereby, a cable television operator having 50 analog
channels will have over 200 digital channels available. This
increased usage of existing bandwidth provides a unique
opportunity to ~take advantage of existing distribution
systems to distribute non-television data.
The present invention is directed to a sophisticated
overall system to widely distribute digital data and collect
consumer information utilizing existing television and
communication networks. The present invention is intended to
be a fully automated system capable of carrying out its
objectives without the benefit of human intervention. It
consists of: (i) a central processing station capable of
receiving user inputs and requests and managing data flow out
to a large number of receiver units; (ii) a novel information
format or data highway structure which ensures that data is
transmitted to remote locations quickly and efficiently and
with a high degree of security; and (iii) an Interactive
Integrated Receiver Tuner (IIRT) for generating user
requests, managing inbound data flow, and providing a fully
functional device management platform for a variety of home
electronics. A bi-directional infrared port is provided with
the IIRT for remote controllers and connection to other
computing devices. In addition, a magnetic card reader is
provided with the IIRT to enable a user to input credit card
information by physically taking a bank credit card and
sliding it through a designated slot on the surface of the
wo gS/ol~ 21 6 4 3 a a PCT~S94/O~f
IIRT. This enables the automatic processing of credit card
information without further input from the user.
This invention utilizes a novel information format based
on an object oriented class that when applied to the
discipline of data distribution systems supports an unlimited
number of data constructs and types, see Figure 10. The
problem with the previous art in this field is that the data
models were very monolithic by nature, i.e., they were not
flexible in the kind or type of transported data content.
This invention solves this problem by defining a base class
that contains methods and objects. By applying this paradigm
to a data highway, the content and function of the highway is
extensible, thus surpassing the static nature of the previous
art in the field.
Several attempts have been made in the past to address
the need for an improved interactive video distribution
system. A prior U.S. Patent to Rhoades, No. 5,051,822
discloses a telephone access video game distribution system.
The system consists of a home computing assembly and a
central remote game storage center. Software video game
programs are transmitted via a modulated carrier to the
subscriber and consist of executable object code transmitted
over st~n~rd cable television lines. Program selection is
controlled by a remote game storage center and billing is
performed automatically over telephone lines. The video game
software is downloaded into a home computing assembly over
st~n~rd cable television links wherein it may be accessed by
the user. Each time the game is accessed, a billing signal
is transmitted to the remote game storage center. This
system is limited to video game and other software
applications. It utilizes a direct transfer of the software
over the cable television distribution system. Rhoades
suffers from the inability to distribute large quantities of
information to many users simultaneously. In addition,
Rhoades does not include any document delivery capability.
A further example of prior art systems is found in the
U.S. Patent to Pocock, et al, No. 5,014,125 directed to a
television system for the interactive distribution of
'109S/01~ 216 4 3 ~ O ~ PCT~S94/0~8
selectable video presentations. The Pocock system is
intended to be a still image television distribution system.
Control signals are transmitted over telephone lines while
video is transmitted over standard cable television lines.
A viewer makes a selection of the program desired which is
transmitted over the telephone lines. A central control
location responds to viewers requests by transmitting desired
video frames to frame gates located at strategic positions
within the topology of the cable system. This effectively
steers the still image television signal to the trunks that
service the viewers location. In contrast with Pocock the
present invention claims improvements over this previous art
as it negates the need for frame gates to steer television
signaling! thus reducing the cost and complexity of deploying
such a system.~ The present invention also claims
improvements over this previous art in that it is not limited
to still frame video.
A still further example is provided in three related U.S.
Patents to Abraham, Nos. 4,590,516, 4,521,806, and 4,567,512.
The Abraham system is directed to a subscriber driven video
distribution system in which a user interactively orders a
video program over the telephone lines, subsequently, the
program signal is transmitted over a standard cable
television line at a prearranged time. The program is either
received in real time or is stored in centralized
distribution centers for redistribution over local cable
television nodes at the prearranged time. This system is
widely known as a "pay per view" system. An improvement on
this prior art can be found in the present invention based on
the use of real time compression / decompression technology.
An improvement on this prior art can be found in the present
invention which is not limited to distributing only
television programming.
A still further example may be found in the U.S. Patent
to Fernandez, No. 4,961,215 directed to continuous automatic
radio distribution system utilizing telephone lines as a
distribution medium. The radio data is transferred via modem
or digital communication device over telephone lines to
WO 95/OlOCO PCT/US94/06401
2164300
remote locations where it may be used immediately or stored
for later use.
A still further example of interactive television systems
may be found in the U.S. Patent to Tindell, et al., No.
5,130,792 directed to the distribution of compressed video
program files to remote stations where such programs are
decompressed and replayed. An improvement on this prior art
can be found in the present invention based on the use of
real time compression / decompression technology. By
negating the need for an onboard high capacity storage
subsystem, the present invention is not structured using a
store and forward architecture, thereby reducing the cost to
the viewer by negating the cost of the associated high
capacity storage subsystem.
Another prio~ art system is set forth in the patent to
McCalley, U.S. Patent No. 4,829,372, 5,119,188, 5,191,410.
McCalley discloses a system whereby compressed video and
audio data is transmitted via cable television lines to
subscribers television sets. Subscribers may scroll through
information being transmitted to their televisions in the
form of video with accompanying audio sequences. The present
invention discloses improvements in the interactive nature of
a home shopping system. Specifically, the present invention
uses actual not simulated menus to allow the user to navigate
the video mall. The viewer simply uses a remote control to
access the functions of the IIRT, and can actually buy
products by using the integrated credit card reading device.
The present invention negates the need for a frame store unit
and is not limited to still frame video presentations.
A still further example may be found in the U.S. Patent
to Hoarty, No. 5,220,420 which discloses an interactive
multimedia system with distributed processing and storage of
video picture information and associated data and sound in
nodes throughout a cable television distribution system. The
present invention addresses structural differences and
improvements over this previous art by negating the need for
the store and forward of video picture information and
associated data and sound in nodes throughout a cable
2l64~ao
rogs/olW~ PCT~S94/06~8
television distribution system. This improvement reduces the
cost and complexity of the system thus reducing cost and
increasing reliability for the viewer.
As will be understood, the system for providing
interactive video programming with remote document generation
of the preæent invention overcomes many of the disadvantages
of the prior art. The difficulties and limitations suggested
in the pr~ce~ing are not intended to be exhaustive but rather
among the many which may tend to reduce the effectiveness and
user satisfaction with prior video distribution systems and
the like. Other noteworthy problems may also exist.
However, those presented above should be sufficient to
demonstrate that prior interactive video systems appearing in
the past will admit to worthwhile improvement.
~UMNARY OF THE l~.vh~.lON
In contrast to the prior art devices which have attempted
to address the need for an improved interactive television
system, the present invention is particularly, although not
exclusively, adapted for use as an interactive television
system which streamlines data transfer to remote television
viewers and returns user inputs and offers the unique
advantage of permitting the generation of hard copy documents
remotely in the home of the viewer.
In the preferred embodiment, the present invention
consists of an improved method and hardware for supporting
interactive television including: (i) a central processing
station capable of providing digital television transmission
and digital command and data transmission; (ii) a remote
receiver unit having
* processing and storage capability to extract
interactive digital commands and or data from a digital
television transmission and or digital data transmission,
* a digital television display support system with
windowing and graphic overlay,
* capability for real time audio and video
decompression,
* a user interface for transmitting user selection
information and accepting credit card information,
wo gS/ol~ 216 ~ 3 0 0 PCT~S94/0~
* a printer station for generating hard copy documents
in the home of a user that can be synchronized with a
television event,
* a graphical user interface,
* a wireless remote controller,
* an interface for DBS,
* a low cost high speed digital expansion interface.
The present invention is adapted to be a wholly
integrated system capable of supporting the entire cycle of
interactive television including item or program selection,
transmission, response and billing. The information formats
or transmission protocols used are preferably, but not
exclusively, directed to a unique digital scheme.
A primary advantage of the present invention is its
ability to enh~nce interactivity between a viewer and the
producer of a video program.
A further advantage of the present invention is its
integrated design permitting all necessary functions
including viewer purchases to be accomplished within a single
automated system.
A further advantage of the present invention is its
ability to produce hard copy documents in the home of a
viewer.
A further advantage of the present invention is its
unique data compression and transmission scheme.
A further advantage of the present invention is its
unique reverse addressing scheme.
A still further advantage of the present invention is its
adaptability to different broadcast methods within a single
system. The present invention is capable of accommodating
cable television, terrestrial, twisted pair hard line, fiber
optic, DBS, and microwave distribution modalities.
A still further advantage of the present invention is use
of individually addressable pixel bit map technology in a
high quality graphics processing system to support refined
graphics programming.
A further advantage of the present invention is its
unique structures for packaging data.
YO95/01~0 2~6~3~o ~ PCT~S94/0~8
A still further advantage of the present invention is its
,use of unique data interleaving methods to accommodate more
efficient data distribution.
A still further advantage of the present invention is
compact design and remote control operation.
A still further advantage of the present invention is the
ease of maintenance to be performed by the user.
A still further advantage of the present invention is its
ability to process consumer credit card information
automatically.
A still further advantage of the present invention lies
in the use of a distributed client / server processing system
permitting system redundancy and facile expansion.
A still further advantage of the present invention lies
lS in the versatile~home receiver unit.
A still further advantage of the present invention lies
in the home receiver unit's unique ability to boot its
operating system from the network.
A still further advantage of the present invention lies
in the unique object oriented base class that defines the
most basic elements of the communication system.
A still further advantage of the present invention lies
in the multitude of consumer choices for programming and
services.
25A still further advantage of the present invention lies
in its ability to communicate to other devices using infrared
communication links.
A still further advantage of the present invention lies
in its ability to display digitally encoded television in
real time.
A still further advantage of the present invention lies
in the receiver unit's ability to execute personal computer
software and games.
A still further advantage of the present invention lies
3S in its ability to decode digital television and digital
command and data transmissions simultaneously.
It is therefore a general object of the invention to
provide a novel interactive television system with document
wo gS/ol~ 216 ~ 3 0 0 PCT~S94/0~
distribution capability or the like which will obviate or
minimize the problems previously described with reference to
the prior art.
It is a specific object of the invention to provide a
novel interactive television system which includes advanced
interactive and processing features.
It is another object of the invention to provide a novel
interactive television system which includes the capability
to produce system generated documents in the home of a user.
It is another object of the invention to provide a novel
interactive television system which includes the capability
to produce system generated documents in the home of a user
synchronized with a television event.
It is still another object of the invention to provide a
wholly integrated interactive television system which
utilizes uniquely packetized data, data interleaving and
digital compression in the same system.
It is still another object of the invention to provide a
wholly integrated interactive television system which
requires no human intervention in order to operate
interactively.
It is a still further object of the invention to provide
a novel receiver unit which includes a user friendly
interactive method of operation and the capability to process
credit card information.
It is a still further object of the invention to inject
commands or digital codes into digital television streams.
It is a still further object of the invention to accept
commands from a television data streams.
Other advantages and meritorious features of the present
invention will be understood from the following description
of the preferred embodiments, the appended claims, and the
drawings, the brief description of which follows.
BRIEF DE8CRIPTION OF THE DRAWINGS
Corresponding components in the various figures are
either designated by the same reference numerals or if
different reference numerals are used their relationship is
identified in the text. The various objectives, advantages
21643~0)O95/01~ PCT~S94/06~8
, ~ ; .
11
and novel features of the invention will become more readily
apprehended from the following detailed description when
taken in conjunction with the appended drawings, in which:
Fig. 1 is a partial perspective and block diagram showing
an ove~view of an interactive television system according to
the invention;
Fig. 2 is a block schematic diagram of a central
processing station in accordance with the invention;
Fig. 3 is a block schematic diagram of an Interactive
Integrated Receiver Tuner (IIRT) in accordance with the
invention;
Fig. 4A is a block schematic diagram of a source select
circuit 110 for the IIRT shown in Fig. 3 in accordance with
the invention;
Fig. 4B shows truth logic tables for operation of source
select circuit 110 as set out in Fig. 4A;
Fig. 4C is a schematic for logic circuitry used to
implement the source select circuit 110 shown in Fig. 4A;
Fig. 5 is a block schematic diagram of a video graphic
subsystem in accordance with the invention;
Fig. 6 is a front plan view of a remote control unit
according to the invention;
Fig. 7 is a flowchart showing an initialization process
for booting an operating system from a central processing
station to an IIRT in accordance with the invention;
Fig. 8 is a block schematic diagram of an object packager
according to the invention;
Fig. 9 is a diagram showing a method for an interleaving
scheme for ordering objects incorporating data in accordance
with the invention;
Fig. 10 is a class diagram showing the base class
structure for an object that travels through a communications
network in accordance with the invention;
Fig. 11 is a class diagram showing the member object
structure for a header object that travels through a
communications network in accordance with the invention;
WO9Sl01W~ - PCT~S94/0~8
2164300
12
Fig. 12 is a class diagram showing the member object
structure for a data object that travels through a
communications network in accordance with the invention;
Fig. 13 is a flowchart for software used to generate a
table of contents for data objects, and incorporate the
generated table of contents in an operating system in
accordance with the invention;
Fig. 14 is a flowchart for software used to size object
data blocks and commence continuous downloading of data
objects in accordance with the invention;
Fig. 15 is a flowchart for software used to accomplish
continuous downloading of data objects from a central
processing station to IIRT units in accordance with the
invention; and
Figs. 16A-C are flowcharts for a method usable between a
central processing station and an IIRT unit for requesting,
delivering and paying for data in accordance with the
invent~on.
DETPTT~ DE8CRIPTION OF THE lNv~ ON
Referring now to the drawings, a partial perspective and
block diagram showing an overview of an interactive
television system according to the invention is shown in
figure 1. The interactive television system according to the
invention shown in figure 1 is generally designated by
reference numeral 10, and includes two major subsystems. One
of these two subsystems is a central processing station 20
having a distribution interface for receiving television
programming, such as from a satellite 24. The other of these
subsystems is an Integrated Interactive Receiver Tuner (IIRT)
unit 40, that is interconnected with the central broadcasting
station 20 using a communications network or transmission
modality. In practice there would be many IIRT units 40,
though only one is shown in figure 1, and there could be
multiple central processing stations 20 depending on
functions and convenience, including the size of the customer
system being served. Communications between a central
processing station 20 and IIRT units 40 is shown in figure 1
as being provided over a coaxial cable television network 32,
VO95/01~ 21 6 4 ~ O O PCT~S9410~8
but such communications for the invention can also be
provided over microwave, satellite 24, fiber optic 33,
telephone with modem, i.e., telco 38, or any other
communications network capable of passing television signals.
Many types of variations in the communications network are
also permissible. For example, depending on topology of the
cable television network 32, it can incorporate use of
Asynchronous Transfer Mode (ATM) and be usable for the
invention.
The central processing station 20 is provided with
automated data processing equipment having sufficient speed
and capacity for supporting real time interactive
transmissions according to the invention. Included, for
example, are a plurality of data servers 832 ("A" through "X"
as shown, but can~be any number), see figure 2, that are used
to originate high speed data streams. These data servers 832
-- the number and capacity of which are selected to satisfy
requirements for providing high speed data streams as
dictated by any particular interactive television system l0 -
- use known Winchester disk drives as manufactured by
Micropolis having several gigabytes of capacity. Management
of high speed data stream processing and transmission for the
invention is accomplished with interface and management
electronics controlled by master computer 800. Additionally,
a multitasking operating system, e.g., UNIX, VAX VMS or
WINDOWS NT, is utilized by master computer 800 to provide
neC~cc~ry data processing and transmission circuit control
for supporting real time transmission of both television
~ G~ r amming and interactive data programming in accordance
with the invention. As used here, interactive data
programming includes data and information. For example, data
and information can include commands and/or software programs
and/or bit map images encoded within a data stream,
multimedia presentations, audio, video, sales catalogs, stock
listings, computer software, video games, etc. As long as
the input for interactive data programming can be formatted
as digital signals, the interactive television system l0 can
support interactive transmission and processing. Master
wo gS/ol~ 2 1 6 4 3 0 0 PCT~S94/0~
computer 800 accordingly needs to be a computer capable of
multitasking functions, e.g., it can be a VAX or ALPHA
computer system as sold by Digital Equipment Corp., a SPARC
10 computer system as sold by Sun Microsystems Inc., a fault
tolerant computer system as sold by Tandem Computers Inc., or
equivalent of these computer systems.
Television signals are provided to the central processing
station 20 via distribution interfaces, such as CATV 30 or
satellite 24. These signals in most cases are digitized at
the central processing station 20. The digitized television
signals are then transmitted from the central processing
station 20 in combination with digitized interactive data
signals over a transmission modality, such as a cable network
32. Any transmission modality capable of passing television
signals can be -used with the invention. Illustrative
interfaces for such transmission modalities are shown in
figure 2 for the central processing station 20 and include
interfaces for a satellite dish 812, and an expanded
communications interfaces 808. A satellite transponder 858,
fiber optic interface 860, terrestrial interface 862, packet
radio interface 864, cellular interface 866 and a telephone
(hereafter telco) interface 868 are all shown for the
ed communications interfaces 808. Each of these
interfaces can provide interconnection to a transmission
modality that would enable the central processing station 20
to communicate with IIRT units 40. These are fully automated
interfaces permitting communication without human
intervention, and are known circuitry used for inputting such
bi-directional signals to processing and transmission
systems.
Interconnected between the expanded communication
interfaces 808 and the master computer 800 can be credit
processing gateway 872, order fulfillment gateway 874, and/or
other goods & services gateway 876. Each of these gateways
is providing a functional capability using known commercially
available equipment. For example, credit processing gateway
872 can include an interconnect using telco 38 to credit
verification equipment operated by TRW, Inc. These gateways
.~09S/01~ 2164 3 0 0 - ~ PCT~S94/0~8
are used for augmenting available services using commercially
available equipment.
It is known that all transmission modalities are limited
in the amount of effective bandwidth that can be passed. In
many cases the amount of bandwidth a transmission modality
can pass is completely consumed with analog television
signals. A requirement, however, of the interactive
television system 10 is that no previously available
television channel be precluded from passage over the
selected transmission modality, and that substantial
additional quantities of interactive data be passed over the
same selected transmission modality. Accordingly, the
invention includes features providing for real time
transmission of substantial additional quantities of data to
support interactive features over transmission modalities
that previously had their bandwidth capacities saturated with
television channels. To achieve this capability the
invention reduces the bandwidth required for transmission of
audio and video television signals and utilizes the residual
bandwidth to transmit interactive data signals between the
central processing station 20 and IIRT units 40 without
disrupting or in any fashion interrupting prior existing
television services. This capability is achieved at the
central processing station 20 through real time analog to
digital conversion of video and audio television signals
followed by compression of the digitized television signals
for transmission. Such analog to digital conversion in
combination with compression reduces video and audio
television signal transmission bandwidth requirements by at
least three-quarters. Typically video and audio signals for
one television channel, when transmitted in analog form,
require a bandwidth on the order of 6 MHz. Therefore, using
analog to digital conversion in combination with compression
and also using properly selected modulation techniques such
as 256 Quadrature Amplitude Modulation (QAM) to achieve high
data symbol rates provides substantial reductions in required
transmission bandwidths per television channel. These
bandwidth requirement savings are more than adequate in
W095/01~ 21 6 4 3 0 ~ PCT~S94/0~
combination with other features of the invention for
transmitting interactive data while still providing complete
television services.
Even further enhancing interactive data handling and
transmission capabilities of the invention is the fact that
the software operating system is based upon object
orientation. Thus, the interactive television system 10
according to the invention utilizes an object oriented class
for transporting interactive data over transmission
modalities. As such an unlimited number of interactive data
constructs and types can be supported using object oriented
classes of the invention. These capabilities are achieved
because, as is known, object orientation provides a better
paradigm, and tools for modeling the real world to achieve
more efficient -results over previous models. Prior
approaches to transmitting data were static because the
transport systems were forced to move the data in fixed sized
packets. Thus, prior data exchange systems were severely
limited in their capacity to process and transmit a wide
range of data types because each prior system could only be
efficient for a particular selected data type, e.g., video
games. If a data exchange system were optimized for video
games, for example, it would not provide efficient data
processing or transmission for video conferencing or other
data intensive applications. As such, this invention using
modifiable object orientation uniquely recognizes and
addresses the need for dynamic data structures to support
multiple application needs. It also supports throughput
capabilities for utilized communicating devices, and adapts
to available network bandwidths and other variables that
effect efficient data transport. The invention can
efficiently manipulate any size data structure because the
object oriented base classes used for the invention can be
adjusted in size.
For the invention, fields labeled object entities are
used to contain interactive data. The field sizes for object
entities are not statically fixed as explained above but are
dynamically adjusted to facilitate rapid data transmission to
`'095/01W~ 2 1 6 ~ 3 0 Q PCT~S94/0~8
all IIRT units 40 for essentially on-demand service in
response to individual user requests as will be explained
below. Allocation of object entity sizes is controlled using
data stored in a system table accessed using master computer
800. Data in this table is indexed according to data class
and sub-class; also included are object entity size data for
particular transmission modality conditions such as usage.
Allocating object entity sizes as a function of interactive
data type and transmission modality, allows the interactive
television system 10 in combination with the selected
transmission modality to operate efficiently under all
conditions. Since data for object entity sizes are stored in
a lookup system table as opposed to hard coded into the
operating system, the invention provides optimum performance
for all object entity types.
In operation user requests are received and data
transmissions are provided by the central processing station
20. Interactive data transmissions can, as discussed above,
include software and other data base information, i.e.,
catalogs, coupon distribution, shop-at-home applications,
theater and sporting event ticket deliveries, banking and
financial services, video game distribution and support,
electronic mail, and virtually any other distributed
interactive data application.
As shown in figure 2 the preferred embodiment for central
~oce sing station 20 incorporates an input from satellite
dishes 812 for receiving television programming, interactive
data, and other signals. Also available for input to the
central processing station 20 is the satellite transponder
858 included in expanded communications interfaces 808.
Other inputs from different sources could be used. However,
those shown in figure 2 are considered adequate to support
the interactive television system 10 according to the
invention. Satellite dishes 812 receive signals from
satellite 24, which can be in geosynchronous orbit. Signals
received using satellite dishes 812 are passed to a satellite
converter circuit 814 for conditioning. The satellite
converter circuit 814 is known circuitry as used in typical
WO95/OlW~ 21 6 4 3 0 0 PCT~S94/0~
18
television receiving stations. Those portions of the
received signal in analog formats are passed through RF tuner
demodulators 816 for further conditioning into individual
channel signals. The RF tuner demodulators 816 can be can be
pur~-hAs~ from Scientific Atlanta, or equivalent. Each
channel signal is then passed to an analog to digital
converter 818 capable of real time analog to digital
conversion of audio and video television signals. The analog
to digital converter 818 can be a device such as those
manufactured by DiviCom, Inc. of Milpitas, California, or
equivalent. The number of analog to digital converters 818
and associated supporting circuitry corresponds to the number
of channels the central processing station 20 will
accommodate. This number is selectable depending on
application, and~in fact the number of analog to digital
converters 818 and associated supporting circuitry can be
greater than the initial number of television channels
serviced so as to provide expansion capacity. Each channel
of digitized signals is then passed for compression to an
audio video compression circuit 820, such as are available
from DiviCom, Inc. of Milpitas, California, or equivalent.
To assure security and prevent program pirating, the
digitized and compressed signal can then be passed through a
data encryption circuit 822, such as a DES circuit, Clipper
25 circuit, DSD circuit as supplied by Teledyne, or equivalent,
prior to retransmission from the central processing station
20. As broadcasters initiate use of digital transmissions,
the need for analog to digital signal conditioning will
di~ini~h. The digitized, compressed and encrypted signals
are then combined using channel multiplexer 830 which is a
device as used for known television broadcasting and are
available from DiviCom, Inc. of Milpitas, California and from
other suppliers. The multiplexed signals are impressed on a
carrier using RF modulator 848. For a preferred embodiment
35 using a coaxial cable transmission modality to transport a
high volume of information, a 256 Quadrature Amplitude
Modulator (QAM) RF modulation scheme can be used. RF
modulators providing 256 QAM modulation are available from
~.~095101~ 21~4 3 o~ PCT~S94/0~8
.
Applied Signal Technologies, Inc., of Sunnyvale, California.
Since different modulation schemes provide better service
depending on system parameters such as transmission modality,
the interactive television system lO of the invention can use
what ever modulation scheme provides the best service. For
example, when a terrestrial transmission modality is
utilized, a VSB modulation scheme can be employed. Fully
capable VSB modulators can be obtained from Zenith Data
Systems. The above-described processing of received analog
television signals is managed by the master computer 800
using gating signals that are passed using gate connection
880 to channel multiplexer 830 and gate connection 884 to RF
tuner demodulators 816.
The central processing station 20 is also capable of
hAn~l ing those - situations where previously digitized
television signals are received by satellite dishes 812. In
such situations the digitized signals are passed from RF
tuner demodulators 816 to channel multiplexer 878, that can
be of the same type and therefore equivalent to channel
multiplexer 830, and the recombined digitized signals are
then passed as shown in figure 2 to an RF modulator 848 for
retransmission. Again, the method for signal processing is
controlled by the master computer 800 using gating signals.
Here gating signals are passed between the master computer
800 and chAnnel multiplexer 878 over gate connection 882.
In operation, the master computer 800 allocates certain
channels for television programming and other channels for
bi-directional interactive data transmission. For example,
the master computer 800 can use specific address information
for particular IIRT units 40 to direct selected signals to
those IIRT units 40 alone.
To perform its functions master computer 800 utilizes
mass memory storage devices, not shown, that can be a bank of
Winchester disk drives, optical disk media, or other high
3 5 speed low cost mass storage systems. Stored on the mass
memory storage devices can be a variety of software programs,
data base information, games, customer information for the
IIRT units 40 of the interactive television system lO, still
WO95/01~ 216 ~ 3 0 0 PCT~S94/0~.
or moving images, or any other digitized interactive data to
be transmitted over the interactive television system 10 of
the invention. Additionally stored on the mass memory
storage devices is the operating system for both the central
processing station 20 and the IIRT units 40. The stored
operating system is booted to the IIRT units 40 as explained
below.
Individual users of the interactive television system 10
are provided with an IIRT unit 40 connected to a conventional
television receiver 26. A remote control unit 52 can be used
for operating the IIRT unit 40. Though a cable network 32
with a CATV Headend 30 is shown in figure 1 as being capable
of supporting all communications between IIRT units 40 and
the central processing station 20, it is again emphasized
that any other~ communications network or transmission
modality system capable of passing digital signals and
television signals can be used including telco 38.
An IIRT unit 40 according to the invention is shown in
block schematic diagram form in figure 3. Principal portions
of the IIRT unit 40 include a central processing unit (CPU)
160 provided with supporting electronics in the form of a
local bus controller 136. This local bus controller 136 can
be a 82420EX PCIset as sold by Intel, or equivalent.
Additionally, there is a memory module 138 that can include
Random Access Memory (RAM) having a two megabyte capacity,
Read Only Memory (ROM) having a 64k byte capacity and data
access memory in the form of a Nonvolatile Random Access
Memory (NVRAM) having a 2k byte capacity such as a DS-1642 as
sold by Dallas Semiconductor, or equivalent. The CPU 160 is
coupled using the local bus 134 to a video coprocessor 122
that can include a graphics coprocessor 124, such as are
available from Texas Instruments and S3 Corp., or equivalent,
and a video Random Access Memory (RAM) 126, such as are
available from Texas Instruments, or equivalent. The CPU 160
can be a 6502 as sold by Signetics, a A80486DX as sold by
Intel, or a PowerPC601 as sold by IBM Corporation, or
equivalent.
YO gS/Ol~ 216 4 3~ ~ PcT~s94lo~8
Principal advantages of the IIRT unit 40 according to the
invention are its capabilities to simultaneously process
large amounts of interactive data and television data in real
time without requiring sophisticated and expensive circuitry
thereby reducing cost and maintenance requirements for the
many IIRT units 40 that would be included in an interactive
television system 10. For example, the IIRT unit 40 though
performing sophisticated processing for a multitude of
signals does not include a mass memory.
From a system perspective, substantial cost savings can
be realized because much of the circuitry incorporated in the
central processing station 20 and the IIRT units 40, though
interconnected in unique arrangements to perform novel
functions, is known and readily available from multiple
sources.
As an example of reducing hardware requirements for the
IIRT units 40 is the fact noted above that there is no
requirement for incorporating any mass memory capability in
the IIRT units 40. In spite of the extensive data storage
and processing capabilities included as part of the central
processing station 20, e.g., mass memory storage devices
included for the master computer 800, the IIRT units 40
operate effectively without mass memory capabilities while
still being capable of real time processing of all received
signals because interactive data is continuously downloaded
from master computer 800. Using continuous downloading
provides essentially on-demand services. As implemented for
the interactive television system 10 of the invention,
continuous downloading includes segmenting digitized data for
continuous broadcasting to IIRT units 40. This continuous
broadcasting is not done so that all data for a single
interactive program is broadcast in an uninterrupted stream
followed by continuous broadcasting of all data for another
interactive program and so forth. Instead, objects from
different interactive programs are interleaved during
continuous broadcasting, or continuous downloading. For
example, if three interactive programs are to be broadcast,
the first object to be broadcast could be for interactive
WO95101~ j PCT~S94/0~8
216430~
22
program one, the second object to be broadcast could be the
first object for interactive program two, and the third
object to be broadcast could be the first object for
interactive program three. This ordering would continue for
second, third and follow-on objects for each interactive
program. When received by IIRT units 40, only those objects
for interactive programs selected by each IIRT unit 40 would
be processed. Each IIRT unit 40 would reject objects for
interactive programs not selected by the end user, and or
authorized by central processing station 20 for reception by
an IIRT unit 40. Thus, each IIRT unit 40 will process
signals for fewer interactive programs than broadcast because
objects for multiple interactive programs are interleaved
during continuous downloading. Individual IIRT units 40 will
therefore not be saturated by the continuous stream of
interactive data being broadcast.
Even further enhancing the invention's data handling
capacities is inclusion of multiple channels for each IIRT
unit 40. A single channel embodiment is feasible but, as
shown in figure 3, the IIRT units 40 for the preferred
emho~;ment include twin channels as represented by signals
passed to R~ tuner & demodulator (1) (element 112) and RF
tuner & demodulator (2) (element 112) from source select
circuits 110. This invention, however, is not limited to
only twin channels because more than twin channels can be
included depending on system requirements. As channels are
added, system capacity increases; however, so also does cost
and complexity.
Incoming signals to IIRT unit 40 are received at source
select circuits 110 that is provided with interfaces to cable
feed 102, microwave feed 162, satellite feed 104, fiber optic
feed 106, and an interface expander 108. The interfaces
identified in figure 3 are not an exhaustive set of
acceptable interface feeds for the invention but are
representative. Adaptability for additional interfaces in
fact is in part provided for via interface expander 108.
Source select circuits 110 includes electronically controlled
bridges that permit reception and routing of signals from any
W095/01~ 2 1 6 4 ~ O ~ PCT~S94/0~W8
input. Specifically included in source select circuits llo
is a cable television interface tuner selector, a satellite
interface tuner selector and a digital data stream router as
shown in the block schematic diagram set out in figure 4A.
Also shown in figure 4A is a RF modulator 848 having an
ouL~ to cable feed 102. This RF modulator 848 is used to
impress interactive data on a carrier for transmission from
IIRT units 40 to the central processing station 20. Though
shown with its output connected to cable feed 102, the RF
modulator 848 can also have its output connected to any of
the other available transmission modalities depending on
which one is being used for bi-directional interactive data
transmission. The RF modulator 848 is equivalent to that
used for the central processing station 20.
A schematic Qf circuitry repeated for every transmission
modality input to the source select circuits 110 is set out
in figure 4C. In particular, the circuitry shown in figure
4C is labeled with inputs and outputs as it would be for
incorporation in the digital data stream router, and is in
fact duplicated in the digital data stream router for both
the fiber optic 106 and interface expander 108 inputs.
O~uLs from these circuits as shown are directed to either
the object packager 131 or the channel demultiplexer 116.
The circuitry consists of a pair of AND gates 190, such as
those incorporated in a TTL 7408 integrated circuit, or
equivalent. Control of this AND gate 190 circuitry to direct
routing of input signals is accomplished in accordance with
logic as set out in figure 4B for the identified example.
Logic signals provided to the identified select inputs are
sent via local bus 134 from CPU 160, and so depending on
provided logic signals the received data input signals can be
directed to either the object packager 131 or the channel
demultiplexer 116, or both. Control signals are received by
~ each IIRT unit 40 from master computer 800 of the central
processing station 20, and are decoded by CPU 160 for the
purpose of providing logic signals for selecting the proper
output port from the source select circuits 110.
WO95/01~ PCT~S94/0~8
216~:QO ~ t"'
24
Both the cable television interface tuner selector and
the satellite interface tuner selector, as incorporated in
the source select circuits llo, include AND gate l9o
circuitry as shown in figure 4C. In the case of such
circuitry for the cable television interface tuner selector
and satellite interface tuner selector the outputs are to the
RF tuner & demodulator (1) (element 112) and the RF tuner &
demodulator (2) (element 112) thereby expanding the signal
handling capacity of IIRT units 40. Gating for this
circuitry again is provided from CPU 160 via local bus 134,
and the controlling logic is identical to that set out in the
truth logic table presented in figure 4B.
All signals provided to IIRT units 40 may not be
transmitted in digitized form. For example, analog
television signa~s may be passed to IIRT units 40 through
cable feed 102 or any of the other transmission modality
inputs. In such situations a filter circuit can be used to
pass the analog television signals to output conductor 42 for
feeding the RF out terminal of the IIRT units 40 as shown in
figure 3. For such an example, the digitized television
signals are passed to the source select circuits 110. This
filtering circuitry can be provided for any or all of the
other transmission modality interfaces depending on
anticipated need.
Previously multiplexed signals directed from the source
select circuits 110 to the channel demultiplexer 116 for
separation into individuals channels for each signal stream.
The ~h~n~el demultiplexer 116 can be a DMX-2000 as sold by
DiviCom, Inc., Milpitas, California, or equivalent. The
demultiplexed channels are then passed to a data decryption
circuit 118, that can be a DigiCypher II descrampler as sold
by General Instruments Corporation, Chicago, Illinois, or
equivalent. Now the demultiplexed and decrypted signals are
passed to a video decompressor circuit 120, that can be a SD4
as sold by C-Cube Microsystems, Milpitas California, or
equivalent, for video signal processing, and a CS4290 as sold
by Crystal Semiconductor Corporation, or equivalent, for
audio signal processing. The audio/video decompressor
WO95101~ PCT~S94/0~8
`-- 216~00~
circuits 120 can utilize MPEG 1 and 2, Digicipher 2, JPEG, or
other standards as dictated by a condition signal provided
from the central processing station 20 within a Table Of
Contents (TOC) that is further discussed with respect to
software shown by flowcharts in fig. 13, as downloaded to the
IIRT unit 40. Now the demultiplexed, decrypted and
decompressed signals are passed to the video coprocessor 122
that includes a graphics coprocessor 124 and a video RAM 126.
The graphics coprocessor 124 can be a programmable DSP such
as a TMS 34010 as sold by Texas Instruments, or equivalent,
and the video RAM 126 as sold by Texas Instruments, or
equivalent. From the video coprocessor 122 the signals are
passed through a channel 3/4 RF modulator 140 so the signal
can be viewed and heard on a conventional analog television
receiver 26 tuned to either channel 3 or 4. Again, the
ch~n~l 3/4 RF modulator 140 is a commercial device available
from multiple sources.
As included in the IIRT units 40, the channel
demultiplexer 116, data decryption circuit 118, audio/video
decompressor 120, and video coprocessor 122 with its graphics
coprocessor 124 and video RAM 126 are all conditioning
previously digitized television signals for viewing and
hearing using conventional analog television receivers 26.
Not only would the cost and complexity of IIRT units 40 be
re~llc~A if these signal conditioning functions were performed
with circuitry included in television receivers, but the
utility of the television receivers would also be increased
as broadcasters initiated digitized transmissions that could
be directly received. A schematic diagram showing circuitry
that could be included in television receivers for so
conditioning previously digitized television signals is shown
- in figure 5. For this circuitry shown in figure 5, the
output of the RF tuner & demodulator 112 in the IIRT unit 40
is directly provided by conductor 107 to a demultiplexer &
3S decryption engine 119 in the television receiver instead of
the data decryption circuit 118 shown for the IIRT unit 40 in
figure 3. The demultiplexer & decryption engine circuits 119
can be a combination of channel demultiplexor 116 and data
WO95/01W~ PCT~S94/0~8
2164300
decryption circuit 118. From the demultiplexer ~ decryption
engine 119 the television signal is passed to an audio/video
decompressor 120 that can utilize MPEG 1 and 2, Digicipher 2,
JPEG, or other st~n~rd as dictated by a condition signal 115
provided from central processor 125. Bi-directionally
connected to the audio/video decompressor 120 is a video
decoder RAM 127 which can be a commercially available VRAM as
are known. The output of the audio/video decompressor 120 is
a decompressed and decrypted video data steam passed to a
digital video combiner 113 that can be a circuit comprised of
known digital logic elements performing an OR function. The
digital video combiner 127 is incorporated as part of a video
coprocessor 122 that is functionally equivalent to the one
shown in figure 3 for the IIRT unit 40. A graphics video
data stream is pr~ovided from the graphics coprocessor 124 to
the digital video combiner circuit 113 which combines it with
the decompressed and decrypted video data stream from the
audio / video decompressor 120. Bi-directionally
interconnected to graphics coprocessor 124 is a graphics
video Random Access Memory (RAM) 130 that can be a
commercially available VRAM as are known. Controlling the
graphics coprocessor 129 through a bi-directional
interconnection is the control processor 125 that can be any
of a 6502, 8051, 6800, Z80 or other known equivalent micro
processor or micro controller with at least an eight bit data
bus.
An output of the digital video combiner 113 is provided
to an NTSC video generator 133, which can be a BT 851 as sold
by Brooktree Corp. of San Diego, California, or equivalent.
From the NTSC video generator 133 an analog video out signal
is provided for display on the cathode-ray tube of the
television receiver. The analog audio output is provided
from the digital to analog converter 114 that can be a CS4290
as sold by Crystal Semiconductor Corporation, or equivalent,
for audio signal processing. Input to the digital to analog
converter 114 is provided from the audio/video decompressor
~20.
WO 95/OIOCO PCT/US94/06408
2164300
Returning to the IIRT unit 40 shown in figure 3, there
are further processing electronics provided to condition
signals received from the central processing station 20 that
are then combined with signals from interactive inputs.
Specifically, an audio processing module circuit 142 that can
be a CS4231 as sold by Crystal Semiconductor Corporation,
Austin, Texas, or equivalent is included to support signals
from interactive ports included as part of the IIRT unit 40.
This audio processing module circuit 142 includes-an audio
coprocessor, digital to analog and analog to digital
converter, audio mixer, audio synthesizers, and midi Input /
Ou~u~ (I/0) to support audio as well as physical interactive
ports.
In addition to the audio processing module circuit 142,
the IIRT unit 40 also includes a peripheral processor 144 for
introducing user provided input interactive signals. The
peripheral processor 144 can be a 68000 as sold by Motorola,
or equivalent. Examples of home user provided input
interactive signals to the IIRT unit 40 that can be supported
by the peripheral processor 144 include:
- signals passed from a remote Local Area Network
(LAN) that would be introduced to the IIRT unit 40 through a
local area network interface 154 that can be an Advanced
Micro Devices Am79C970; or
- signals from remote computer equipment, such as
keyboards, that are introduced to the IIRT unit 40 through
computer peripherals circuit 152, that can be a National
Semiconductor 87334; or
- signals for playing electronic games, such as
from joy sticks, that can be passed through game port 156; or
- signals from a magnetic card reader 70 for
- inputting credit card information; or
- signals can be provided by the home user
through a conventional remote control 52 (see figures 1 and
6) communicating with the infrared remote control transceiver
54 that can be a National Semiconductor 87334.
The infrared remote control transceiver 54 can be capable
of providing a bi-directional link for communicating with the
WO95/01~ ~ PCT~S94/~8
2164300 28
IIRT unit 40 and other like equipped devices. Bi-directional
communications with the IIRT unit 40 using the peripheral
processor 144 is also possible using modem 46 with telco 38.
In particular this communications link over telco 38 can be
used for data transmissions between IIRT unit 40 and the
control processing station 20.
Additionally, the peripheral processor 144 can be used to
provide information and data directly to the home user on a
Liquid Crystal Display (LCD) display 56 that can be a Sharp
Electronics Corp. LM40255, or through the printer 60 that can
be a AXIOHM Inc. HTP-8050. All of these capabilities and
others can be readily added thereby allowing the IIRT unit 40
to serve as an extensive and adaptable home electronics
integration system. This capacity to provide home
electronics inte~ration system capability is achieved not
only by providing interfaces for facsimile machines, home
stereos, Compact Disk (CD) players, Video Cassette Recorders
(VCR) and computer equipment such as personal computers, disk
drives, keyboards and joy stocks, but also by providing
interfaces that can be used to monitor / control security
systems and household utilities such as water, gas and
electricity.
To even further support interactive functions there is a
capability to display graphics and other message formats on
the television receiver 26 and LCD display 56 using signals
from the IIRT unit 40. In this manner, the user is prompted
through menus or other provided information to efficiently
select in a user friendly fashion services available from
IIRT unit 40.
In addition to mounting LCD display 56 on the IIRT unit
40, it can also be mounted on remote control 52, see figure
6. As so mounted, displayed information can easily be read
by a user holding the remote control 52. Information from
the IIRT unit 40 can be displayed on such a remote control 52
because the infrared remote control transceiver 54 provides
bi-directional communications to and from the remote control
52. Control buttons 58 are provided on the remote control 52
to input data. Also provided on the remote control 52 is a
wo ~/ol~ 2 1 6 4 3 0 0 PCT~S94/0~8
track ball 64, joy stick or equivalent that can be used to
adjust positions of objects displayed on the television
receiver 26.
As stated above, a magnetic card reader 70 can be
interconnected to the IIRT unit 40 through the peripheral
processor 144. Magnetic card readers 70, sometimes known as
card swipe readers, commercially available. They transform
magnetically coded information stored on credit cards to
digital bit streams identifying the card owner's name, card
number, expiration date, and other relevant information.
Having a magnetic card reader 70 allows an IIRT unit 40 user
to simply and accurately enter credit card information when
making a purchase or paying a bill. The peripheral processor
144 receives the digital bit stream signal from the magnetic
card reader 70, and in cooperation with the CPU 160, the IIRT
unit 40 stores the signal in the RAM portion of memory module
138. The signal is then compressed and encrypted for
transmission to the central processing station 20. This
automatic and direct ability to download credit card
information to the central processing station 20 reduces the
risk of credit card fraud and misappropriation. The process
for transmitting such data from the IIRT unit 40 to the
central processing station 20 is discussed below.
Using the printer 60, it is possible to provide home
users of the interactive television system 10 with printed
documents including tickets and coupons. The printer 60,
depending on selected equipment, which is unrestricted by the
invention, can utilize dot matrix or other conventional
printing t~chniques capable of producing letter quality print
and graphics. For the preferred embodiment, the printer 60
is of stAn~rd design and is driven using conventional
printer sequences. To substantially eliminate user
maintenance obligations the printer 60 can utilize a paper
and ink cartridge 62. Compact design can be achieved if
printer 60 provides two to four inches of printing width.
This amount of printing width provides sufficient space for
producing coupons, tickets, receipts and other documents.
Thus, documents ranging from coupons to lottery tickets, and
WO95/01~ PCT~S94/0~8
216~3QO
from receipts to messages can be conveniently produced for
the home user.
Turning to software and methods employed for the
interactive television system 10, the software utilized for
initialization, including booting of the operation system to
IIRT units 40, is now described with reference to figure 7.
As stated above, the operating system for all IIRT units 40
is booted from the central processing station 20 every time
an IIRT unit 40 is turned on. The process begins when the
home user brings power to the IIRT unit 40 (Step 900) by, for
example, activating a switch that causes electrical voltage
and current to be brought to all IIRT unit 40 devices (Step
910). After powering up, the CPU 160 using data stored in
the NVRAM portion of the memory module 138 directs the RF
tuner & demodulat~or (2)(element 112) to be tuned for passing
signals on the ch~nnel used by the central processing station
20 for transmitting the operating system. If for some reason
the previously identified channel is not active, i.e., the
operating system is not being downloaded on this channel, the
RF tuner & demodulator (2)(element 112) is directed by the
CPU 160 to tune to the next channel so an evaluation of
whether that channel is active can be made. If that next
c-~Annel is not active then the RF tuner & demodulator
(2)(element 112) is directed to tune to the next channel
until the active channel is obtained (912). Data for the
operating system, which is continuously downloaded from the
central processing station 20, is packaged in objects having
a header identifiable by the object packager 131 in the IIRT
unit 40. It is such identification by object packager 131
that is used to confirm a channel as being active. When an
object is received by an IIRT unit 40 with an operating
system header, the contained packaged data is loaded into RAM
138 (Step 914). Next a check of the booted operating system
data is conducted to assure accuracy and authenticity of the
received data. This check is accomplished using an algorithm
stored in the ROM of the memory module 138 (Step 916). If
the data fails to comply with the check, the process for
downloading is repeated as shown in figure 7. In the
wo gS/ol~ 216 ~ 3 ~ O PCT~S94/0~8
_ .
alternative, if the check is passed, the CPU 160 directs a
jump to the operating system and IIRT unit 40 operations are
begun.
It is seen from this discussion of how the operating
system is booted to IIRT units 40 that the object packager
131 functions as a filter to identify objects received at
both the IIRT units 40 and the central processing station 20.
This identification is accomplished by reading each object
header, which are described below. These object he-aders are
coded using digital data incorporated in fields within the
object. Exemplary circuitry for an object packager 131 is
shown in block schematic form in figure 8. The specific
example shows circuitry usable for reading four bit headers.
The invention, however, is not so limited. Object hearers
incorporating greater or lesser bit patterns can be
accommodated by straight forward scaling of the suggested
circuitry or its equivalent. As shown a received object
header signal is input to a four bit parallel access shift
register 90 that can be a Texas Instruments 74LS95.
Concurrently the four bit pattern for the object header that
is to be read is input from local bus 134 to a four bit
parallel latched bus transceiver 92 that can be a Texas
Instruments 74LS226. The outputs of the four bit parallel
latched bus transceiver 92 and the four bit parallel access
shift register 90 are input to a four bit magnitude
comparator 94 that can be a Texas Instruments 74LS85. When
the bit pattern for the selected object header as input to
the four bit parallel latched bus transceiver 92 matches that
of the input to the four bit parallel access shift register
90, the four bit magnitude comparator 94 outputs a signal
indicating the selected object is being received, and is
ready for further processing. In this fashion the IIRT units
40 and central processing station 20 can identify and pass
- objects for processing. Such reading and passing of
identified object headers is accomplished in the central
processing station 20 circuitry using an object packager 131,
as shown in figure 8, or equivalent, that is included in the
expanded communications interfaces 808. As so located,
WO95101~ ; PCT~S94/0~8
2164~ 32
received signals are read, identified and selectively passed
after passing through the interfaces.
Whether objects contain operating system data or other
interactive data, they are always transmitted in an
interleaved fashion so as to accomplish continuous
downloading according to the invention. The method for
interleaving transmitted objects is depicted in figure 9.
For purposes of explanation here, the upper portion of figure
9 shows three different interactive data Programs, i.e., A,
B and C, all of which are to be transmitted from the central
processing station 20. Also shown in the upper portion of
figure 9 is the fact that the included interactive data is
segmented and incorporated in objects l, 2, 3, etc. for each
~-G~lam. The lower portion of figure 9 shows an organization
for interleaved continuous downloading transmission on a
single c~Annel according to the invention. In the case of
this example, the interleaving technique positions object l
for PLo~Lam A to be transmitted first, and this transmission
is immediately followed by object l for Program B, which is
followed by object l for Program C, and so forth. According
to this interleaved continuous downloading technique, no
object from the same ~-o~-am is transmitted immediately after
a transmission of any other object for that same Program.
Therefore, no IIRT unit 40, for this example, is required to
download more than every third object on a channel.
Irrespective of the example, moreover, no IIRT unit 40 is
required to download two or more consecutively transmitted
objects. All downloaded objects are followed in transmission
by at least one object that is not downloaded. As explained
above, use of this interleaved continuous downloading
technique enables IIRT units 40 to accomplish real time
processing of received data using cheaper and less
sophisticated electronics than would be required for real
time processing of interactive data continuously received for
the same Program.
As identified above, the interactive television system lO
according to the invention utilizes object oriented classes
for transporting interactive data over transmission
wo gSloloCo 2 1 6 4 3 0 0 PCT/USg41~8
modalities. Accordingly, an unlimited number of interactive
data constructs and types are supported by the unique object
oriented classes of the invention. These capabilities are
achieved using the unique object oriented classes of the
invention because object orientation provides better
paradigms and tools for modeling the real world to achieve
better an~ more efficient results than do previous non-object
oriented structures. A system, in general, must comply with
four rules to be object oriented:
- Abstraction must be a characteristic used by
each kind of object to distinguish it from all other kinds of
objects. In terms of the invention, abstraction is initiated
from the base class, see figure lo, because the base class
includes the least common elements essential for constructing
each kind of object that can be transported over a
transmission modality.
- Encapsulation must be utilized so that elements
of the abstraction are compartmentalized. For example, the
invention uses an encapsulated object address 504 in the base
class, see figure 10, for enabling proper receipt of an
object over a transmission modality.
- Modularity must be a property of an object
system permitting decomposition into a set of cohesive but
loosely coupled modules. In terms of the invention,
modularity is incorporated in the definition of the base
class shown in figure 10 so it can be loosely and cohesively
coupled to extended sets of objects that share a common
structure and behavior, i.e., classes, through a relationship
among classes, and also share the structures or behavior
defined in other classes. These relationships are known as
inheritance.
- Hierarchy must be utilized for ranking or
ordering of abstractions within the system. Since the base
class, see figure 10, is constructed using the minimum number
of elements required for an object according to the
invention, all subsequent classes are built from the base
class. Such construction from a base class defines an
hierarchy of objects. Inheritance, because of hierarchy,
WO95/01~ PCT~S94/0~8
~164300
34
enables code and structure sharing among objects, thus
creating a source of reusable modules.
Prior approaches for organizing and transporting interactive
data and information were static. Thus, prior interactive
systems were severely limited in their capacity to process
and interchange interactive data. The invention, however, is
not so limited because of its use of object oriented base
classes that can grow to include different kinds of objects
for sharing. For example, polymorphism, as used in known
object orientation technology, can be used for relating
objects according to the invention from many different
classes under a common superclass.
A class diagram showing a base class structure for an
object that can travel over transmission modalities accordinq
to the inventioAn is shown in figure 10. The object
structures for the invention are assembled at the central
processing station 20 using the master computer 800 or at the
IIRT unit 40 using the CPU 160. After assembly using the
master computer 800 or the CPU 160, the digital signals for
the object are transmitted using shift register devices such
as sixteen bit parallel in serial out shift registers, which
can be 74LS674 devices as sold by Texas Instruments, or
equivalent. For the IIRT unit 40 the sixteen bit parallel
serial out shift register, used as an object creator 143, can
be included between the local bus controller 134 and the RF
modulator 848 as shown in fig. 4A; while, for the central
processing station 20 this object creator 143 can be included
with the master computer 800 as is the mass memory.
A separately encapsulated start of object identifier 502 and
object address 504 are utilized by the present invention.
Prior art directed toward transmitting data utilized a static
or fixed size packet that had a non-adjustable capacity of,
for example, 1024 or 4096 bytes. The present invention,
however, is not so constrained because the object entity 506
is a variable size field capable of being tailored to system
needs. Each object can thus have its object entity 506 size
adjusted by master computer 800 or CPU 160 to optimize
performance of interactive television system 10. Both the
WO9S/01~ 2 1 6 ~ 3 ~ O PCT~S94/0~W8
prior art and the present invention utilize an error
correction value 508 field, which can be a Cyclic Redundancy
Code (CRC) algorithm, as are known, and a postamble or end of
object identifier 510 field to complete the base class.
A member object structure class diagram for a header
object according to the invention is shown in figure 11. The
class diagram set out in figure 11 shows that the header
object inherits properties from the base class shown in
figure 10. The start of object identifier 502,-shown in
figure 11, enables an IIRT unit 40 or central processing
station 20 to recognize the start of an incoming object as
such, using an object packager 131 and is inherited from the
base class shown in figure 10. For the header object shown
in figure 11, the object entity 506 includes a variety of
fields used to further identify an object so an IIRT unit 40
or central processing station 20 can selectively download a
particular object entity 506. For example, using the IIRT
address 248 field a preselected IIRT unit 40 can be
identified for receiving an object entity 506 as shown in
figure 11. Set out in the following table by field
identification are the respective corresponding functions for
an header object according to the invention.
Header Obiect
25 Field Identification Function
Data Block Identifier 226 Provides identification
information at the data block
level.
Byte Count 228 Provides the number of bytes of
data within the object.
Offset Address 230 Provides offset address from
the beginning of the object, to
permit flexibility in ordering
of objects.
35 Encryption Type Code 232 Identifies type of encryption
used to encrypt data block.
Compression Type Code 234 Identifies type of compression
used to compress data block.
WO95/01~ ; PCT~S94/0~8
2164300
Data Class & Subclass 236 Identifies type of data being
transmitted, e.g., object code,
software code, graphic data for
video display or hard copy
printing, etc.
Next Object Channel 238 If a new channel needs to be
used for transmitting the next
object, e.g., to optimize
system performance, this field
identifies that information.
Next Object ID 240 Identifies the Object Address
230 for the next object.
Next Object Data Block
ID 242 Identifies the Data Block
~ Identifier 226 for the next
object.
System Time 244 This field provides data to
synchronize events to a common
time base.
Receipt Validation Code 246 Provides the code information
used for confirming receipt of
a particular transmission.
IIRT Address 248 Identifies a preselected IIRT
unit 40 for receipt of an
object.
Command Code 250 Used to direct execution of
system level commands, e.g., to
print a document.
Command Data 252 Field contains data to
implement execution of system
level commands, e.g., data to
be printed on document.
Future Use 254 Field reserved for future use.
Now, a member object class diagram for a data object
according to the invention is shown in figure 12. Again, the
class diagram set out in figure 12 shows inheritance of
WO95/01~ PCT~S94/0~W8
216~300 ~ ~
~ ,~
37
properties from the base class shown in figure 10, and
inheritance of properties from the header shown in figure 11.
Within the data object is an object entity 506 containing a
data header 222 and a data block 224. The data header 222
includes data block identifier 226, byte count 228, and
offset address 230 fields. These data header 222 fields
provide the information for achieving the functions as set
out in the procee~ing table. The data block 224 contains
interactive data, and as explained above, is an adjustable
sized field tailored to provide maximum system efficiency.
Therefore, objects according to the invention are members of
a base class and as such inherit dynamic object entity size.
Substantial transmission efficiency is achievable when
interactive data is bi-directionally transmitted using both
objects and interleaved continuous downloading according to
the invention. This efficiency is realistically demonstrated
by considering an interactive television system 10 that is
capable of transmitting 24 megabits per second which is 3
mega bytes per second. Such transmission rates are
reasonable when using presently available equipment. For the
situation where 16 different start of object identifiers 502
are allocated at any one time (interleave factor of 16), and
each object is sized at 2,048 bytes, there would be a 10.9
millisecond period required to transmit each individual
object. Stated differently 92 individual objects for each of
the 16 different start of object identifiers 502 would be
transmitted every second. This number results from dividing
the bytes transmitted per second by the product of the
individual object size and the interleave factor. Assuming
a system overhead of 10 percent for non-interactive data in
each object, which may be high, and an interactive data
stream 350 K bytes long, which is the size of a typical
dictionary in a word processing program, a period of 33
seconds would be required to transmit the 350 K byte stream
along with a similar amount of interactive data for the other
sets. This example illustrates the reason why the
invention can effectively be used as an on-demand interactive
WO95/01~ PCT~S94/0~8
216430~ .
system for bi-directional transmission of substantial amounts
of interactive data.
Referencing figure 13, a flowchart for software used for
preparing interactive data for transmission in object form
over transmission modalities is shown. This software is used
to collate information from source object files for
interactive data to be transmitted including: start of
object identifiers 502; encryption type codes 232;
compression type codes 234; and data class & subclasses 236
(see figure 11). Execution of the software is performed
using master computer 800 in the central processing station
20 and results are transmitted to CPU 160 in IIRT unit 40.
To begin operations using the software all databases or
source object files containing information regarding
interactive data to be transmitted are opened (Step 202).
After opening these databases for reading, a list is
generated (Step 204) of all enabled files including those
from gateway streams, i.e., credit processing gateway 872,
order fulfillment gateway 874, and other goods & services
gateway 876 (see figure 2). This listing from enabled source
object files now includes at least: sufficient information
for writing start of object identifiers 502; encryption type
codes 232; compression type codes 234; and data class &
subcl~ses 236 (see figure 11).
Using this list, a Table of Contents (TOC) file (Step
208) is written and used by master computer 800, and is
continuously downloaded to all IIRT units 40. At this point
operation of the software described by the flowchart set out
in figure 13 is complete.
Next master computer 800 uses software as described by
the flowchart in figure 14 for preprocessing interactive data
for transmission in object form in an interleaved continuous
downloading fashion as illustrated in figure 9. First, the
TOC 208 from Step 208 shown in figure 13 is loaded into the
memory buffer (Step 522) of master computer 800. This memory
buffer is then scanned and all listed objects are opened for
reading including TOC file 208 (Step 524). A header object
is next generated (Step 526) for each of the opened files.
W095/01~ PCT~S94/0~8
216430Q
Now that header objects are generated, the master
computer 800 using object data class & subclasses 236 listed
in TOC 208 references system tables stored at master computer
800 to determine optimum data block 224 sizes (Step 527).
This is a look-up process with optimum data block 224 sizes
listed in the system tables as a function of operating
conditions.
The starting and ending offset addresses 230 for each
object data block 224 is now generated in list form (Step
528). Finally, a file titled DATABLKS.DAT containing each
object header, followed by the list of beginning and ending
data block offset addresses 230 for each object is generated
and saved in memory (Step 530). At this point operation of
the software described by the flowchart set out in figure 14
is complete.
Objects are now available for transmission and must be
interleaved in accordance with the organization described in
figure 9. To accomplish this task, software as described by
the flowchart shown in figure 15 is used. First, the
nATART~S.DAT file, from Step 530 in figure 14, is loaded from
disk (Step 302). Now sufficient memory capacity must be
allocated (Step 304) to accommodate a list large enough to
point to all header objects and data blocks 224 that were
loaded using the DATABLKS.DAT file in Step 302. With this
memory capacity available, the software directs successive
pointing to each header object and data block 224, so as to
create a list of pointers that interleave the data blocks 224
for continuous downloading (Step 308). The software now
executes a looping through of the list of pointers, an
updating of header object and data block 224 system
information, and can direct outputting of objects in their
assigned order. However, because the DATABLKS.DAT file is
being continuously updated, the software compares the loaded
D~ARTx~.DAT file (Step 302) with the version in memory (Step
310). If there is a difference, the software reinitiates
Step 302 and proceeds. If there are no differences, the
software returns to Step 308 and completes the operation. The
IIRT 40 downloads a fresh copy of the TOC header before
WO95101~ PCT~S94/0~8
216~300
downloading an object to verify that the TOC in IIRT memory
is current. If the TOC in IIRT 40 memory is not current, the
IIRT 40 downloads a new TOC into IIRT 40 memory.
Flowcharts for a method, using this invention, to request
and pay for transmission of interactive data from a central
processing station 20 are set out in figures 16A through 16C.
The method begins with a user of IIRT unit 40 inputting a
signal using remote control 52 or other signal generator to
request specific interactive data (Step 402). This inputting
of a request signal can be in response to selecting a
particular item from a displayed menu, or from any range of
information made available to IIRT unit 40 users.
The IIRT unit 40 will select the transmission modality
for communicating with the central processing station 20,
which can include use of modem 146 and telco 38. After the
transmission modality is selected, the IIRT unit 40 transmits
both the request signal and the identification code for the
requesting IIRT unit 40 to the central processing station 20
(Step 406). Upon receipt of the IIRT unit 40 identification
code and the request signal, the master computer 800
references a previously stored look-up table to determine
whether the identified IIRT unit 40 is in good standing,
e.g., all outstanding charges have been paid (Step 410). If
the identified IIRT unit 40 is not in good standing, the
central processing station 20 transmits an error report
signal to the identified IIRT unit 40 for display (Step 411).
In the alternative, if the identified IIRT unit 40 is in good
st~n~ing, the master computer 800 proceeds to reference a
second previously stored look-up table to determine the
charge associated with transmission of the requested
interactive data or service (Step 414). If there is a
charge, then the amount of that charge is transmitted back to
the IIRT unit 40 and displayed on television receiver 26 or
LCD display 56. In response to this information, the user
can initiate transmission to the central processing station
20 of a signal with credit card information using magnetic
card reader 70. Upon receipt of the signal, the charge card
information is validated as to whether the charge card is in
WO95/01~ 216 4 3~ ~ PCT~S94/0~8
41
good st~n~ing for payment of the charge. This validation
(Step 415) can be accomplished using the other goods &
services gateway 876 as discussed above. If the charge card
is not validated as being capable of covering the charge,
then an error report is transmitted to the IIRT unit 40 (Step
417). For those situations when either no charge is made for
the transmission or the transmitted charge card information
is validated as being capable of covering the required
payment, the master computer 800 proceeds to allocate for
transmission the object address 504, data block identifier
226, next object channel 238, and delivery schedule (Step
416). This allocated information is now transmitted from the
central processing station 20 to the IIRT unit 40 (Step 418).
If the transmitted object is to be encrypted, then an
encryption type code 232 is also transmitted to the IIRT unit
40. All preparations for transmission of the object are now
completed and the object is transmitted to the IIRT unit 40
(Step 424).
If the transmitted object meets the previously identified
delivery schedule (Step 426), and if there is no charge for
the transmission (Step 428), then the process is complete.
However, if the transmission did not meet the previously
announced delivery schedule, then the IIRT unit 40 transmits
an error signal to the central processing station 20 (Step
432) and delivery of the object is rescheduled (Step 434).
To accomplish redelivery, the process must return to Step
418.
Again, if the transmission did meet the announced
delivery schedule (Step 426) and there is a charge for the
transmission (Step 428), then the IIRT unit 40 transmits a
receipt validation code 426 to the central processing station
20 (Step 436). At this point actual payment is made. If
Step 436 is not executed, no payment is made because the IIRT
unit 40 has not acknowledged receipt of the requested
interactive data. Finally, if required, the central
processing station 20 transmits an encryption type code 232
so the received objects can be decrypted. Further, if
WO95101~0 PCT~S94/06408
216430~ --
42
documents are to be printed, the necessary signals are
transmitted to printer 60 (Step 438).
The above discussion and related illustrations of the
present invention are directed primarily to a preferred
embodiment and practices of the invention. However, it is
believed that numerous changes and modifications in the
actual implementation of the concepts described herein will
be apparent to those skilled in the art, and it is
contemplated that such changes and modifications may be made
without departing from the scope of the invention as defined
by the following claims.
