U.S. patent application number 09/736393 was filed with the patent office on 2002-02-28 for system and method for broadcasting web pages and other information.
Invention is credited to Augenbraun, Joseph E., Grosky, Aaron, Kunkel, Gerard K., Plotnick, Bruce.
Application Number | 20020026642 09/736393 |
Document ID | / |
Family ID | 26866437 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020026642 |
Kind Code |
A1 |
Augenbraun, Joseph E. ; et
al. |
February 28, 2002 |
System and method for broadcasting web pages and other
information
Abstract
A system and method for interactive broadcast of Internet web
pages, or the like, on dedicated downstream channels in a cable
television system or the like facilitates hyperlinking by a user
from a broadcast television program to a web page, or between web
pages, for example. In one embodiment, each user's set top is
programmed with channel mapping information that maps each
hyperlink request to a particular channel and time where the
requested information is being broadcast in a multiplexed
information stream. In response to receipt of a hyperlink request
from a user actuating a remote control button, mouse or keyboard,
the set top tunes to the appropriate one of the downstream
channels, and downloads the web page or other information. In one
embodiment to facilitate picture-in-picture capability using a
single tuner, the tuner in the set top briefly tunes away from the
video program to the appropriate data channel for receiving the
hyperlink information. After the information associated with the
hyperlink is downloaded and stored in the set top, the tuner
automatically tunes back to the video program. The user can then
interact with the hyperlink content and continue watching TV
simultaneously. Alternatively, a scaler application is provided in
the headend that reduces the size of the video program or a content
related web page, for example, so that they can then be combined at
the headend in a picture-in-picture format.
Inventors: |
Augenbraun, Joseph E.;
(Princeton, NJ) ; Kunkel, Gerard K.; (Yardley,
PA) ; Grosky, Aaron; (Doylestown, PA) ;
Plotnick, Bruce; (Jamison, PA) |
Correspondence
Address: |
William A. Blake, Jones, Tullar & Cooper, P.C.
P.O. Box 2266 Eads Station
Arlington
VA
22202
US
|
Family ID: |
26866437 |
Appl. No.: |
09/736393 |
Filed: |
December 15, 2000 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60170792 |
Dec 15, 1999 |
|
|
|
Current U.S.
Class: |
725/109 ;
348/E7.071 |
Current CPC
Class: |
H04N 21/4782 20130101;
H04N 21/2362 20130101; H04N 7/17318 20130101; H04N 21/8586
20130101; H04N 21/858 20130101; H04N 21/4622 20130101; H04N 21/4316
20130101; H04N 21/234363 20130101; H04N 21/4345 20130101; H04N
21/4722 20130101; H04N 21/812 20130101; H04N 21/2665 20130101 |
Class at
Publication: |
725/109 |
International
Class: |
H04N 007/173 |
Claims
1. A system for broadcasting information over a television
distribution network comprising: a) a network headend for accessing
information from one or more sources, and broadcasting said
information; b) a plurality of downstream channels interfaced to
said headend for transmitting said information; and c) a plurality
of terminal devices for receiving said downstream channels, each
said terminal device including: 1) a tuner for receiving and
selecting said downstream channels; and 2) a terminal processor for
receiving channel selection and information requests from a user,
and instructing said tuner to select one of said downstream
channels, said terminal processor including programming for
receiving an information request from a user, and in response
thereto, instructing said tuner to select one of said downstream
channels on which said requested information is being transmitted
from said headend.
2. The system of claim 1, wherein said terminal device further
includes a memory containing a channel mapping database for
identifying, for each of a plurality of possible information
requests received from a user, a one of said channels on which said
requested information is being transmitted from said headend.
3. The system of claim 2, wherein said headend further includes at
least a first multiplexer for multiplexing a plurality of
information data streams on one of said downstream channels, each
of said information data streams containing information identified
by a corresponding one of said plurality of information requests;
and said channel mapping database further includes timing
information identifying a time slot in a multiple time slot
sequence when each of said information data streams is to be
transmitted.
4. The system of claim 3, wherein said terminal processor is
further programmed to identify from said channel mapping database,
a time at which said one of said information data streams
containing said requested information is to be transmitted on said
one of said downstream channels, and for instructing said tuner to
select said one of said downstream channels at said time.
5. The system of claim 2, wherein said terminal device further
includes a memory for storing said information data streams, and a
display manager for formatting said information for display on a
video monitor interfaced to said terminal device.
6. The system of claim 5, wherein said display manager further
includes a picture-in-picture application for simultaneously
displaying first information stored in said memory, and second
information being received on one of said downstream channels.
7. The system of claim 1, wherein said headend further includes an
encoder for digitally encoding information data streams to be
broadcast and said terminal device further includes a decoder for
decoding said information data streams, said encoder being
programmed to generate a full image frame periodically to
facilitate synchronization of said decoder with said encoded data
stream.
8. The system of claim 1, wherein said requested information
comprises Internet web page data, said web page having content that
is related to a video program that is being received by said tuner
at a time that said information request is received by said
terminal processor.
9. The system of claim 1, further including an input device for
entering information requests into said terminal processor either
through actuation of a button on said input device, or selection of
an on-screen button displayed on a video image.
10. A terminal device for receiving information transmitted on a
plurality of downstream channels in a television distribution
system, and formatting said information for display on a video
display device, said terminal device comprising: a) a tuner for
receiving and selecting said downstream channels; b) a memory for
storing channel mapping and information request identification
information; and c) a processor for receiving an information
request from a user, said processor being programmed, in response
to receipt of said information request, to access said memory to
identify first information specified by said request, determine a
first of said channels on which said first information is to be
transmitted, and cause said tuner to select said first of said
channels to receive said first information.
11. The terminal device of claim 10, wherein said processor is
further programmed to download said first information into a cache
in said memory, and then instruct said tuner to select a second of
said channels that is transmitting second information that was
being received when said information request for said first
information was received by said processor.
12. The terminal device of claim 11, further comprising a display
manager for formatting first images corresponding to said first
information stored in said memory and second images corresponding
to said second information in a picture-in-picture format for
simultaneous display on a display device interfaced to said
terminal device.
13. The terminal device of claim 10, wherein said channel mapping
database contains information that maps each of a plurality of
possible information requests to one of said downstream channels on
which corresponding information is to be transmitted.
14. The terminal device of claim 13, wherein said channel mapping
database further includes time slot information identifying a time
slot in a multiplexed data stream in which information
corresponding to each information request is to be transmitted.
15. The terminal device of claim 14, wherein said processor is
further programmed to instruct said tuner to select said first
channel just prior to transmission on said first channel of said
first information in said multiplexed data stream.
16. The terminal device of claim 10, further including a second
tuner for downloading channel mapping and information request
identification information into said channel mapping database.
17. The terminal device of claim 10, wherein said device is a set
top converter box for receiving a plurality of cable television
channels.
18. The terminal device of claim 17, wherein said information
request comprises a request for Internet-based information that is
related to a content of a video program that is being received by
said tuner when said information request for information is
received by said processor.
19. The terminal device of claim 10, wherein said information
request comprises a request for information selected from the group
comprising Internet-based information, program guide information
and user account information.
20. The terminal display device of claim 10, further including a
wireless receiver for receiving information requests from a
wireless input device.
21. A method for requesting and receiving information in a
television distribution network comprising: a) providing a network
headend for accessing information from one or more sources, and
broadcasting said information; b) providing a plurality of
downstream channels interfaced to said headend for transmitting
said information; c) providing a plurality of terminal devices
interfaced to said downstream channels for receiving information on
said channels, and formatting said information for display on a
display device, each said terminal device including a tuner for
receiving and selecting said downstream channels, and a terminal
processor for receiving information requests from a user, and
instructing said tuner to select one of said downstream channels;
d) receiving a request for information in said terminal device from
an input device; e) identifying a one of said downstream channels
on which said information is to be transmitted; f) causing said
tuner to select said one of said downstream channels; and g)
receiving said requested information with said terminal device.
22. The method of claim 21, wherein said terminal device further
includes a memory containing a channel mapping database for
identifying, for each of a plurality of possible information
requests received from a user, a one of said channels on which said
requested information is being transmitted from said headend, and
said step of identifying a one of said downstream channels on which
said information is to be transmitted comprises accessing said
channel mapping database to identify said channel from said
information request.
23. The method of claim 22, wherein said terminal processor further
identifies from said channel mapping database, a time at which said
requested information is to be transmitted on said one of said
downstream channels, and said step of causing said tuner to select
said one of said downstream channels, further comprises causing
said tuner to select said one of said downstream channels at said
time.
24. The method of claim 21, further comprising the step of: h)
storing said requested information in a memory in said terminal
device.
25. The method of claim 24, further comprising the steps of: i)
after said requested information is stored in said memory, causing
said tuner to select a second of said channels to which said tuner
was tuned when said information request was received by said
terminal processor, said second of said channels transmitting a
second information stream; j) formatting said requested information
and said second information stream into a combined
picture-in-picture image data stream; and k) supplying said image
data stream to a display device.
26. The method of claim 21, further comprising the steps of
encoding information in said headend to be broadcast to form a
plurality of encoded data streams, said encoding including periodic
generation of a full image frame, and decoding said encoded data
streams in said terminal device.
27. The method of claim 21, wherein said requested information
comprises Internet web page data, said web page having content that
is related to a video program that is being received by said tuner
at a time that said information request is received by said
terminal processor.
28. The method of claim 21, wherein the step further of receiving a
request for information in said terminal device from an input
device, further includes entering said request either through
actuation of a button on said input device, or selection of an
on-screen button displayed on a video image.
29. A terminal device for receiving multiple information streams
and forming a picture-in-picture image information stream therefrom
comprising: 1) a tuner for receiving and selecting a plurality of
channels, each of said channels transmitting one or more
information streams; 2) a terminal processor for instructing said
tuner to select one of said downstream channels; 3) a memory for
storing information received on said downstream channels; and 4) a
display manager having a picture-picture graphics application for
retrieving information stored in said memory, and combining it with
an information stream that is being received by said tuner on one
of said downstream channels to form a picture-in-picture image data
stream for simultaneous display of said stored information and said
information stream on a display device interfaced to said terminal
device.
30. A method for receiving multiple information streams and forming
a picture-in-picture image data stream therefrom comprising the
steps of: a) providing a terminal device having a tuner for
receiving and selecting a plurality of channels, each of said
channels transmitting one or more information streams; b) receiving
a first information stream on one of said channels; c) storing said
first information stream in a memory in said terminal device; d)
receiving a second information stream on one of said channels; e)
combining said first information stream with said second
information in a picture-in-picture format to form a combined image
data stream; and f) supplying said combined image information
stream to a display device for simultaneous display of images
corresponding to said first and second information streams.
31. A network headend for accessing information from one or more
sources, and broadcasting said information over a television
distribution network, said headend comprising: a) at least one
scaler for receiving a first image generating information stream
and generating a scaled version of said first information stream
having a reduced image size; and b) at least one multiplexer for
combining said scaled version with a second image generating
information stream to form a combined information stream, said
combined information stream being formatted in a picture-in-picture
format where a first image generated by said first image generating
information stream is overlaid on a second image generated by said
second image generating information stream.
32. The headend of claim 31, further including an encoder for
encoding said scaled version prior to being combined with said
second information stream.
33. The headend of claim 31, wherein said first information stream
is a video program, and said second information stream is selected
from the group comprising an Internet web page, a television
program guide and user account information.
34. The headend of claim 33, wherein said second information stream
comprises an Internet web page that is related to a program content
of said video program.
35. A method for transmitting multiple information streams in a
networked distribution system comprising the steps of: a) providing
a first image generating information stream; b) scaling said
information stream to form a reduced size image generating
information stream; c) combining said reduced size image
information stream with a second image information stream in a
picture-in-picture format to form a combined image information
stream; and d) transmitting said combined image information stream
through a distribution network.
36. The method of claim 35, wherein the steps of scaling and
combining are carried out in response to a request received from a
terminal device for said second information stream, and said step
of transmitting further comprises transmitting said combined image
information stream to said terminal device.
37. The method of claim 35, wherein said first information stream
is a video program, and said second information stream is selected
from the group comprising an Internet web page, a television
program guide and user account information.
38. The method of claim 37, wherein said second information stream
comprises an Internet web page that is related to a program content
of said video program.
Description
PRIORITY CLAIM UNDER 35 USC 119 (e)
[0001] The present application claims the benefit, under 35 USC 119
(e), of U.S. Provisional Application Nos. 60/170,792 and
60/170,793, both filed Dec. 15, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a system and method for
broadcasting information, such as Internet web pages, over a
networked distribution system, such as a cable television
distribution system.
[0004] 2. Description of the Background Art
[0005] U.S. Pat. No. 5,961,603, issued Oct. 5, 1999, U.S. Pat. No.
5,999,979, issued Dec. 7, 1999, and U.S. Pat. No. 6,049,539, issued
Apr. 11, 2000, all of which are hereby incorporated by reference,
disclose systems and methods for providing interactive access to an
information source, such as the Internet, through a networked
distribution system, such as a cable television distribution
system. In a conventional cable television distribution system,
video programming originating from remote and local sources is
broadcast from a cable headend, through a plurality of downstream
channels to a set top converter box (set top) located at each
user's premises. The set top interfaces the received programming to
the user's television or monitor, and includes a tuner that is used
to select the channel to be viewed, typically by receiving commands
from a remote control operated by the user. In the system disclosed
in the '603 patent, a cable television user who is a subscriber to
a special Internet access service, can access Internet web pages
that are related to the present programming content of a cable
television channel being viewed by the user. This technique is
referred to as CHANNEL HYPERLINKING. In addition, the user can
"surf" the Internet in a conventional manner with this system.
[0006] In the preferred embodiment disclosed in the '603 patent,
the cable television distribution system includes a number of
modifications for processing hyperlinking requests from the users.
First, at least one upstream channel is provided between each user
and the cable headend so that a user can enter hyperlinking
requests into their set top, and forward them to the cable headend
for processing. The cable headend processes each request by
accessing a hyperlink database containing URL's (web addresses) of
programming-content related Internet web pages, and retrieving a
URL that has been assigned to the channel that the user is viewing
for the time period during which the request is made. The cable
headend then retrieves the web page from the Internet, or from
memory, with an Internet browser application located in the
headend, and downloads the web page to the user for viewing. As an
example, the user, who may be viewing a television advertisement
for a particular product, can thus hyperlink to a web page for that
product with this system.
[0007] The preferred embodiment of the channel hyperlinking system
disclosed in the '603 patent thus provides a convenient technique
for enabling users to access additional information that is related
to the content of the program they are currently viewing, by simply
pressing a button on their remote control. However, the preferred
embodiment is not designed for use with cable systems that provide
only one-way communication between the cable headend and the system
users, since the upstream channel is necessary to send channel
hyperlinking requests to the headend.
[0008] Another feature that would be desirable in a channel
hyperlinking system is "picture-in-picture" capability, wherein a
user can simultaneously view both a broadcast television program
and a content related web page, for example, so that they can
continue watching television while interacting with a channel
hyperlink, or conducting an Internet session. For example, the
television program could be a scaled image within the web page, or
vice versa. Picture-in-picture is easy to provide in a two-tuner
set top where one tuner receives the video program, while the other
tuner receives the channel hyperlink data. However, the typical set
top only has a single in-band tuner that can be used for either
video or data.
SUMMARY OF THE INVENTION
[0009] The present invention addresses the foregoing issues through
provision of a networked distribution system that facilitates
channel hyperlinking capabilities without the need for upstream
channels, and also provides picture-in-picture capability without
the need for multiple tuners. In a first preferred embodiment of
the invention, the system is designed to provide continuous
broadcast of Internet web pages, and other information, on one or
more downstream channels. This system facilitates Internet access,
including channel hyperlinking, without the requirement that
information or hyperlinking requests be sent through an upstream
channel for processing by the cable headend. Instead, hyperlink
requests are processed in each user's set top converter box by a
terminal processor that is programmed to identify a downstream
channel on which the requested information is being broadcast, and
instruct the set top's tuner to switch to that channel.
[0010] More particularly, to implement this embodiment of the
present invention, the cable headend is modified to broadcast
Internet web pages or other information on one or more downstream
channels. Preferably, a multiplexing scheme is employed wherein
each downstream channel broadcasts information for multiple web
pages, or the like, in a carouseled manner in which multiple,
repeating time slots are provided, one for each web page or groups
of web pages to be broadcast. The multiplexing arrangement greatly
increases the effective bandwidth of each channel, and provides for
infinite scalability so that any number of web pages or other
information may be continually broadcast over a limited number of
channels. This is made possible by the fact that most web pages
contain a limited amount of information, the majority of which is
static. It is thus feasible to transmit the information for each
page on a periodic basis, e.g., once every 10 seconds or so, with
the only consideration being the amount of time that a user will be
willing to wait for the requested information to arrive.
[0011] The set top's terminal processor recognizes Internet access
and channel hyperlink requests that are directed to any of the
broadcast web pages. More particularly, the terminal processor
accesses a channel mapping database in the set top that maps each
request received from a user via a remote control, keyboard or
other input device, to the appropriate downstream channel and time
slot therein, which is identified by a packet identifier (PID), on
which the requested information is being broadcast. Using the PID
information, the terminal processor instructs the set top's tuner
to switch to the designated channel, and downloads the web page
information for display on the user's television. To facilitate
efficient downloading of the requested channel hyperlink content,
the terminal processor preferably waits until the data of interest
appears in the carousel at the headend, and then instructs the set
top's tuner to switch away from the television channel that a user
is currently viewing. The requested content is downloaded into a
cache in the set top, and the tuner is then instructed to switch
back to the original program channel. In this manner, the amount of
time that the user cannot watch their program during downloading of
the requested hyperlink content is minimized.
[0012] The foregoing arrangement also facilitates
picture-in-picture capability without requiring the provision of
two tuners in the set top. To achieve this, the terminal processor
runs any suitable display manager program having picture-in-picture
capability, which accesses the hyperlink content stored in the set
top's cache, and overlays the content over the television program,
or vice versa. The user can then simultaneously conduct an Internet
session and continue watching the television program, for
example.
[0013] There are a number of other changes that are preferably made
in the headend to facilitate accessing of the web pages or other
information being broadcast on the downstream channels. The first
change involves the data encoding (e.g., MPEG 1 or MPEG 2) that is
employed to encode the web page image data to reduce bandwidth
requirements. In two-directional channel hyperlinking where the
headend responds to a hyperlink request by downloading the content
related information on a downstream channel, it is only necessary
to transmit a full frame of image data, known as an I-frame, at the
beginning of the transmission, and when the next image frame
differs completely from the previous image frame. Otherwise, it is
adequate if only differences between one image frame and the
previous frame are transmitted. These are referred to as difference
frames, and substantially reduce the bandwidth required for
transmitting the information. However, in one-way channel
hyperlinking, the headend does not have knowledge when a viewer has
requested a hyperlink. It is thus necessary to send full I-frames
every second or so to insure that set tops that tune to the channel
get an I-frame within a short enough time period that the viewer is
satisfied with the service. Thus, for any channel that is
designated by the system to be a broadcast channel for web pages,
the encoder is programmed to send full I-frames frequently enough
that a viewer who is just tuning in, will not have to wait long for
receipt of the web page data.
[0014] In another preferred embodiment of the present invention,
single tuner picture-in-picture capability is provided in an
alternative manner by formatting, combining and encoding the
information for both data streams in the headend, and transmitting
the combined data on one of the downstream channels to the user's
set top box. This arrangement is particularly suited for use with
the preferred embodiment disclosed in the '603 patent where channel
hyperlink requests are sent to the headend via an upstream channel,
or other communications link. When a hyperlinking request is
received from a set top, processing equipment in the headend
accesses the content related information, and combines it with a
reduced, scaled version of the video programming that the user was
viewing at the time the hyperlink request is sent. This combined
information is then sent to the user's set top on one of the
downstream channels. In the case of a content related web page, the
set top will display the web page on the user's television or
monitor with a reduced size image of the associated television
program overlaid on a portion of the page. Alternatively, the size
of the web page can be reduced so that the web page is overlaid on
a full size television program. Thus, this alternative embodiment
of the invention also provides picture-in-picture capability
without the need for more than one tuner in the set top, and
without the requirement that the additional image information be
sent separately from the video program information.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The features and advantages of the present invention will
become apparent from the following detailed consideration of a
preferred embodiment thereof, taken in conjunction with the
accompanying drawing figures, in which:
[0016] FIG. 1 is a block diagram of a CATV system that is
constructed in accordance with the preferred embodiments of the
present invention;
[0017] FIG. 2 is a block diagram of a cable headend that is
employed in the system of FIG. 1; and
[0018] FIG. 3 is a block diagram of a set top converter box that is
employed with the system of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Turning now to a detailed consideration of a number of
preferred embodiments of the present invention, FIG. 1 is a general
block diagram of a CATV system 10 which incorporates elements for
facilitating access and broadcast of Internet web pages and other
information to a plurality of system users. The system 10 is
illustrative of one type of system with which the concepts of the
present invention may be employed. It should be noted that the CATV
system 10 is illustrated in general form since many of its detailed
elements are not necessary for an understanding of the present
invention.
[0020] The CATV system 10 includes a cable headend 12 and a cable
television distribution network 13 for interfacing the headend 12
to a plurality of terminal devices, which are preferably set top
converter boxes 14 (set tops), but could be any other suitable
receiving and processing device. A plurality of transmission links
15 interconnects the set tops 14 with the distribution network 13.
Each of the links 15 is illustrated as being bi-directional with a
plurality of downstream channels 16 and one or more upstream
channels 17. The upstream channel 17 can be used, for example, for
sending information from the set tops 14 to the headend 12, such as
two-way channel hyperlinking requests in accordance with the method
set forth in the '603 patent.
[0021] The cable headend 12 receives video programming and
Internet-based and other information from remote sources (not
shown), and transmits the video programming and other information
through the distribution network 13 to the set tops 14.
Alternatively or additionally, the information may be stored in one
or more local databases 18 in, or interfaced to, the headend 12.
The information can comprise many types of information, for
example, television programming information, user account
information, and advertisements.
[0022] Each of the set tops 14 is interfaced via a number of
communication links 19 (e.g., cables, infrared wireless links,
etc.) to a television or monitor 20 for displaying the received
video programming and other information, and one or more input
devices, such as a wireless keyboard 22 and a remote controller 24,
for user interaction with the set top 14.
[0023] The details of the elements in the headend 12 are
illustrated in FIG. 2. Typically, the video programming that is
received by the headend 12 is in either an analog format, or a
digitally compressed or encoded format, such as MPEG 1 or MPEG 2.
The Internet-based information, on the other hand, is typically
HTML coded web pages along with still images coded in JPEG or GIF
formats. The web pages are generated either by a web page generator
25 located in the headend 12, or by a web page generator at a
remote location. As set forth in the '603 patent, the CATV system
10 allows a system user that is a subscriber to an Internet access
service, to conduct an Internet session by sending appropriate
commands via the keyboard 22 and/or remote controller 24 to a
processor 26 in the headend 12. The headend processor 26 processes
a hyperlink request by accessing a hyperlink database 27 that is
either located in, or interfaced to, the headend 12, and retrieving
a URL for the web page to be downloaded. The headend processor 26
then connects the user to one of a plurality of browser
applications 28, retrieves the requested Internet information from
the remote source or the local database 18, and downloads the
information to the user's set top 14 for display on their
television or monitor 20. In addition, the first preferred
embodiment of the present invention also includes the capability of
processing hyperlink and other Internet access requests in each of
the set tops 14. As will be shown, this is made possible by
continually broadcasting any number of Internet web pages from the
headend 12, and providing the set tops 14 with channel and time
slot information for each of the web pages. In this instance, the
web page data is supplied to the browser applications 28, one for
each web page to be broadcast, to generate web page bit map images
to be broadcast to system users.
[0024] Preferably, additional data is added by the web page
generator 25 (or by a remotely located web page generator) to the
usual encoded image data to indicate relationships between the
channels and which key sequences are to be used to select which
channels. This data comprises linkage commands that are used to
traverse the broadcast channels by menu instead of by channel, and
to hyperlink to web pages from hyperlinks embedded in the broadcast
channels. Though similar to tuning to a channel from a set
top-resident channel guide, this differs in that the tuning would
not be to a channel, but to a content stream and would be more like
hyperlinking among web pages. Also, when broadcasting to set tops
that can access the channel hyperlinking service disclosed in the
'603 patent, the pages can provide links that function as access to
this service.
[0025] To facilitate insertion of the linkage commands in the HTML
web page data, the web page generator is preferably provided with a
plug-in referred to as a linkage editor 29. The browser
applications 28 are able to accept the linkage commands and
generate data in the broadcast stream that would specify to set
tops 14 the linkage commands on the current page.
[0026] An Internet session manager 30 is provided which starts the
browser applications 28 and a display manager 32. The browser
applications 28 and display manager 32 are interfaced to a
communications manager 34 to facilitate downloading of the web
pages to the system users. A video encoder 36, which may be an MPEG
1 or MPEG 2 encoder, for example, is also preferably provided in
the headend 12 for encoding the web page bit map images before they
are transmitted by the distribution network 13 to the set tops 14.
The encoder 36 is employed to reduce the bandwidth necessary to
transmit the data generated by the browser application 28, and to
generate, for example, an MPEG standard compliant video stream.
[0027] From the encoder 36, the web page data for each of the web
pages is passed through one or more digital multiplexers 38, each
of which combines a plurality of the web pages into a single data
stream that is fed to the distribution network 13 for broadcast on
a corresponding digital one of the downstream channels 16. Each of
the multiplexers 38 act as a carousel by employing a time division
multiplexing scheme in which the data for each web page is assigned
a time slot in a multiple time slot, repeating sequence. The number
and length of slots in the sequence is selected based on the type
and amount of information to be sent. In the event that the
information is the HTML data for a static web page, then it is
sufficient to send this data only once every 10 seconds or so,
since each set top 14 need only receive the data once.
[0028] In one embodiment of the invention for implementing
picture-in-picture graphics presentation without the need for
multiple tuners, one or more scaler applications 39 are provided in
the headend 12 for selectively reducing the size of either the
video programming images or the web page images, so that one may be
overlaid on the other. As is well known, a picture-in-picture
format displays information in windows on a television screen that
are a fraction of the size of an entire display screen. The reduced
size and resolution of picture-in-picture images require less image
data to be transmitted, and less bandwidth utilized, than is
required to display a full screen image. In this embodiment of the
present invention, the resulting excess bandwidth is utilized to
transmit one or more overlays of information with the reduced image
for display on a single television screen. Such overlays may
include, but are not limited to, additional full motion video
programs, web pages retrieved from the Internet, advertisements and
television programming information.
[0029] The scaler applications 39 receive the incoming video
programming or the web pages from the remote or local sources, and
reduce the size of the video images by a predetermined amount
before they are fed to one the encoders 36. The scaled and encoded
video or other images are then multiplexed by one or more of the
multiplexers 38, and may be combined with the other image
information. As previously stated, with the advent of true
interactive television, the present invention permits a user to
simultaneously view a television program and conduct an Internet
session utilizing a television with a single tuner. As information
is retrieved by one of the browser applications 28, it is either
encoded and multiplexed with the scaled and encoded video
programming, or it is encoded, scaled and multiplexed with the
video programming. The encoded and multiplexed data stream is then
distributed via the distribution network 13 to the set top 14. The
data stream may thus be displayed in a picture-in-picture format
even where the set top 14 contains no scaling means and the system
maintains a single tuner.
[0030] With reference to FIG. 3, the details of one of the set tops
14 are illustrated. A tuner 40 is provided for receiving the
digitally encoded or compressed video programming and
Internet-based information from the distribution network 13 on each
of the downstream channels 16, and selecting the one of the
downstream channels 16 from which information will be displayed on
the television or monitor 20. From the tuner 40, the selected
information passes through a decoder 42 which restores the video
programming signals and web page image data to their original form
for display on the television or monitor 20. The decoder 42 is of
the same format as the encoder 36, such as MPEG 1 or MPEG 2, for
example. In the case of a two-way system, an upstream transmitter
43 is also provided for transmitting hyperlink requests and other
information to the headend 12 via the upstream channel 17.
[0031] The heart of the set top 14 is a terminal processor 44 that
controls operation of the tuner 40 in response to requests received
by an input receiver 45 (e.g., an infrared receiver) from the user
via the keyboard 22 or remote controller 24. The terminal processor
44 is interfaced to a channel mapping database 46 that is contained
in a memory 48, and stores channel mapping and hyperlink request
identification information for any number of user selectable
channel hyperlinks or assessable web pages or sites. For example,
the user may actuate the hyperlink button on their remote
controller 24 during a news, weather or sports television
broadcast, and the terminal processor 44 will access the channel
mapping database 46 to identify the hyperlink request, and
determine on which of the downstream channels 16, and in which time
slot or PID, related Internet based information (e.g., news,
weather or sports web site) is being broadcast.
[0032] The terminal processor 44 determines the identity of the
hyperlink using the linkage commands that are inserted by the
linkage editor 29 at the headend 12. More particularly, an input
application 49 is run by the terminal processor 44 that processes
inputs received by the input receiver 45 by detecting when either
the channel hyperlink button on the keyboard 22 or remote
controller 24 has been pressed, or when a hyperlink button on a
currently displayed image has been highlighted and selected by the
user. Once the hyperlink request and corresponding channel and time
slot information have been identified, the terminal processor 44
will then instruct the tuner 40 to switch to the designated channel
so that the requested information can be downloaded into the set
top 14 for display by a terminal display manager 52 on the user's
television or monitor 20. A cache 50 can be provided in the memory
48 for pre-storing downloaded information if desired. To facilitate
downloading of channel mapping and hyperlink request identification
information from the headend 12 to the channel mapping database 46,
an out-of-band tuner 54 can be provided that can also be used for
transmission of signaling information, as is conventional.
Alternatively, the channel mapping and hyperlink request
identification information can be downloaded through one of the
downstream channels 16 for reception by the in-band tuner 40.
[0033] In another embodiment of the invention for facilitating
picture-in-picture capability using the single in-band tuner 40,
the terminal processor 44 controls the tuner 40 in the following
manner. For example, when the user enters a channel hyperlink
request (e.g., by pressing the channel hyperlink button on the
remote controller 24), the tuner 40 is instructed by the terminal
processor 44 to briefly tune away from the television program to
the appropriate data channel for receiving the hyperlink
information. Any web pages or other information associated with the
hyperlink are downloaded and stored in the set top's cache 50, and
then the tuner 40 automatically tunes back to the television
program. The user can then interact with the hyperlink content and
continue watching the television program simultaneously using any
suitable picture-in-picture graphics application that is programmed
into the display manager 52.
[0034] To minimize the amount of time that the user cannot watch
their program, the time-map of the channel hyperlink content that
is stored in the channel mapping database 46 is employed by the
terminal processor 44 to delay tuning off of the video channel
until the data of interest appears in the multiplexer 38 at the
headend 12, and is about to be broadcast. For example, if the
multiplexer carousel is ten seconds long and the user presses the
hyperlink button, there may be as much as a ten second wait for the
data to appear in the carousel. Without using the time mapping
information, and assuming a one second tuning time, the user would
miss an average of eight seconds of their television program when
pressing the channel hyperlink button (one second to tune to data
channel, average of five seconds for data to come around in the
carousel, one second to collect and process the data, and one
second to tune back to video programming). However, by using the
time mapping information, this delay can be reduced to three
seconds: one second to tune the data channel, one second to collect
and process the data and one second to tune back to the television
program.
[0035] In the preferred embodiments of the present invention, a
number of additional features are preferably employed. One feature
involves the encoding procedure implemented by the encoder 36. To
encode the web page image bit map data generated by the browser
applications 28, the encoder 36 employs any known conventional
algorithm for encoding motion picture video frames, such as MPEG 1
or MPEG 2. The first frame is encoded as an intra or I frame where
information for all of the pixels in the frame needs to be
transmitted since no previous frame information is available. In a
hyperlinking application where a specific user is receiving web
page data, the next frame in the sequence can then be encoded
either as an P (predictive) frame or a B (bi-directional
predictive-coded) frame which includes only the difference or
motion vector data resulting from the frame comparisons. P or B
frames can continue to be used for encoding the succeeding frames
in the sequence until a substantial change, such as a scene change,
occurs, thus necessitating formation of another I frame. The use of
P or B frames substantially reduces bandwidth requirements since
considerably less data has to be transmitted.
[0036] However, the foregoing technique is preferably modified in
the embodiment of the present invention where web pages are
continually broadcast on a selected channel to all system users. In
this instance, it is preferable that the encoder 36 transmit a full
I-frame frequently enough (e.g., once every second) that any of the
set tops 14 which tune to the channel get an I-frame within a short
enough time period that the viewer is satisfied with the service.
Further, with this broadcast service, the stream must be constantly
generated since the stream offers no feedback indicating how many
of the set tops 14 are viewing the cable channel (stream) or when a
set top tunes to or from a cable channel carrying the stream.
[0037] The headend communications manager 34 and its configuration
are also preferably modified so that the configuration file can
specify that a downstream channel is a broadcast channel, and will
also specify a channel number that will be used when the
communications manager 34 establishes an Internet session with the
Internet session manager 30. That channel number is used to access
an initial URL from the hyperlinking database 27. Whenever the
communications manager 34 does not have an Internet session
associated with the broadcast channel, the communications manager
34 establishes a session with the session manager 30. To do this,
the communications manager 34 generates a hyperlinking login using
the configured channel. The URL from the hyperlinking database 27
will be the first page displayed on the broadcast channel. That
page may be the only page or may be one of a series of pages
displayed at intervals (current HTML can step through the series of
pages).
[0038] The broadcasting embodiment of the system 10 thus
facilitates broadcast of web pages and other information over a
group of channels to all users of the system 10, regardless of
whether they are subscribers to an Internet access service offered
by the cable company. This design not only supports the broadcast
of static web pages, but support series of web pages and animated
web pages. The system 10 can be used to broadcast several channels
containing such diverse pages as stock ticker/news, headline
news/sports, scrolling/paging detail reports, program guide
information, weather and advertising. On a simple system the pages
would be virtually unrelated, though they could suggest tuning to
another channel for more details on stories. On a more advanced
system, the pages could contain instructions to the set tops 14 so
that pressing key sequences would automatically tune to the
details.
[0039] The picture-in-picture embodiments of the invention permit
requested information to be simultaneously displayed along with a
video program, for example, that a user is currently viewing. As an
example, in a two-way application, if a user sends a hyperlink
request to the headend 12, the headend processor 26 will retrieve
the requested information, e.g., web page, start one of the browser
applications 28, combine the web page information with a reduced
size version of the video program that the user is currently
viewing by first applying the program to the scaler application 39,
and download the combined information stream on one of the
downstream channels 16. The set top processor 44 will then be
instructed to switch the tuner 40 to that channel. In the one-way
broadcasting embodiment, the same result is achieved by first
downloading the web page information into the set top's cache 50,
and then combining the stored information with the received video
program using a picture-in-picture application in the set top
display manager 52.
[0040] Although the invention has been disclosed in terms of a
number of preferred embodiments and variations thereon, it will be
understood that the scope of the invention as defined by the
following claims is not limited thereto. For example, the preferred
embodiments are directed to a cable television distribution network
having Internet access capabilities. However, the concepts of the
present invention can be applied to any type of networked broadcast
distribution system that is capable of accessing or hyperlinking to
any type of additional information.
* * * * *