U.S. patent application number 11/918087 was filed with the patent office on 2009-11-12 for systems and methods for collecting media broadcast audience participation data.
Invention is credited to Ajay Gupta, Chandrasekar Venkatraman.
Application Number | 20090282430 11/918087 |
Document ID | / |
Family ID | 34967340 |
Filed Date | 2009-11-12 |
United States Patent
Application |
20090282430 |
Kind Code |
A1 |
Gupta; Ajay ; et
al. |
November 12, 2009 |
Systems and Methods for Collecting Media Broadcast Audience
Participation Data
Abstract
Systems and methods for collecting viewership data of television
and radio broadcast programs. The methods include receiving an AV
signal of a broadcast program and supplementary content which
contains a tag identifying the broadcast program. The supplementary
content is combined with the AV signal to form a data-augmented
signal which is subsequently modulated with a carrier signal to
form a transmit signal for broadcasting to receivers. Each receiver
includes a decoder for extracting the supplementary content and
recording the tag identity and time the tag is received. The
recorded information is subsequently output to an electronic device
or sent directly to a viewership data collection entity.
Inventors: |
Gupta; Ajay; (Karnataka,
IN) ; Venkatraman; Chandrasekar; (Saratoga,
CA) |
Correspondence
Address: |
HEWLETT-PACKARD COMPANY;Intellectual Property Administration
3404 E. Harmony Road, Mail Stop 35
FORT COLLINS
CO
80528
US
|
Family ID: |
34967340 |
Appl. No.: |
11/918087 |
Filed: |
September 27, 2005 |
PCT Filed: |
September 27, 2005 |
PCT NO: |
PCT/IN2005/000325 |
371 Date: |
October 9, 2007 |
Current U.S.
Class: |
725/20 ; 725/119;
725/133 |
Current CPC
Class: |
H04H 60/66 20130101;
H04N 21/434 20130101; H04H 20/28 20130101; H04H 60/61 20130101;
H04N 21/44213 20130101; H04N 21/25891 20130101; H04N 21/258
20130101; H04N 21/4508 20130101; H04H 20/38 20130101; H04H 60/73
20130101; H04H 60/33 20130101; H04H 60/94 20130101; H04N 21/4755
20130101; H04H 60/74 20130101; H04H 20/91 20130101; H04H 2201/30
20130101; H04H 2201/20 20130101; H04H 20/30 20130101; G02B 6/29374
20130101; H04N 21/4532 20130101; H04N 21/4722 20130101 |
Class at
Publication: |
725/20 ; 725/133;
725/119 |
International
Class: |
H04H 60/32 20080101
H04H060/32; H04N 7/173 20060101 H04N007/173 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2005 |
IN |
PCT IN2005 000124 |
Claims
1. A monitoring method comprising: receiving a transmit signal at a
receiver, the transmit signal containing a program and a
supplementary content associating therewith; demodulating the
transmit signal to provide a data-augmented signal; recovering the
supplementary content from the data-augmented signal at
substantially the same time the program is rendered at the
receiver; and keeping a record upon successfully recovering the
supplementary content.
2. The method of claim 1, wherein recovering the supplementary
content comprises outputting the data-augmented signal to a decoder
where the supplementary content is extracted, the supplementary
content having a data portion and a meta-data portion containing a
tag identifying the program.
3. The method of claim 2, wherein keeping the record comprises
recording the tag identity and time the tag is detected.
4. The method of claim 3 further comprising sending the record to a
data collection entity.
5. The method of claim 4, wherein sending the record comprises
arranging the record in a pre-determined format prior to sending
the same to the data collection entity.
6. The method of claim 4, wherein sending the record comprises
automatically sending the record to the collection entity at a
specified time.
7. The method of claim 4, wherein sending the record comprises
sending the record to the collection entity in response to a
request.
8. The method of claim 4, wherein sending the record comprises
sending the record to an electronic device and thereafter to the
data collection entity using a communication infrastructure of the
electronic device.
9. The method of claim 8 further comprising providing the
electronic device with an application for editing the record before
sending the same to the data collection entity.
10. The method of claim 1 further comprising: combining the
supplementary content with an AV signal of the program to provide
the data-augmented signal, wherein the supplementary content is
inserted into a non-program portion of the AV signal, the
supplementary content having a data portion and a meta-data
containing a tag identifying the program; and modulating the
data-augmented signal with a carrier signal to provide the transmit
signal for broadcasting.
11. The method of claim 10, wherein combining the supplementary
content comprises inserting the supplementary content into the
non-program portion of the AV signal at a regular interval.
12. The method of claim 10, wherein combining the supplementary
content comprises inserting different supplementary contents into
non-program portions corresponding with different program segments,
each of the supplementary contents having at least a different tag
in the meta-data for identifying the different program
segments.
13. The method of claim 12, wherein each supplementary content
further includes information relating to the different program
segments.
14. The method of claim 10, wherein the AV signal comprises a
television signal having a vertical or horizontal blanking interval
for use as the non-program portion and the receiver comprises a
television.
15. The method of claim 10, wherein the AV signal comprises a
digital audio broadcasting signal having a program associated data
channel for use as the non-program portion and the receiver
comprises a digital radio.
16. A monitoring system comprising: a receiver for receiving a
transmit signal and demodulating the same to provide a
data-augmented signal, the transmit signal containing a program and
a supplementary content relating thereto, the supplementary content
including a data portion and a meta-data portion having at least a
tag for identifying the program; and a decoder coupled to the
receiver for receiving the data-augmented signal and recovering the
supplementary content therefrom, the decoder including a monitoring
application for keeping a record upon successfully recovering the
supplementary content.
17. The system of claim 16, wherein the record comprises the tag
identity and the time the tag is detected.
18. The system of claim 16 further comprising a communication means
for sending the record to a data collection entity.
19. The system of claim 16 further comprising an electronic device
coupled to the decoder for receiving the record and sending the
record to a data collection entity using communication means of the
electronic device.
20. The system of claim 19, wherein the electronic device is a
printer and the communication means is a fax machine connected to a
telephone line for sending the record printed out using the printer
to the data collection entity.
21. The system of claim 19, wherein the electronic device comprises
one of a mobile phone, PC, and a PDA and the communication means
comprises at least one of a cellular network, Internet connection,
and a cable link.
22. The system of claim 21, wherein the electronic device includes
an editing application for editing the record before sending the
same to the data collection entity.
23. The system of claim 16 further comprising: an inserter for
combining the supplementary content with an AV signal of the
program to provide the data-augmented signal; and a modulator for
modulating the data-augmented signal with a carrier signal to
provide the transmit signal for broadcasting.
24. The system of claim 23 further comprising a content server for
storing and providing the supplementary content to the
inserter.
25. The system of claim 24, wherein the content server comprises a
synchronizing signal between the content sever and the inserter for
coordinating the combining process.
Description
FIELD OF INVENTION
[0001] The present invention relates to systems and methods for
polling audience participation in media broadcasts. More
specifically, it relates to systems and methods for collecting
viewership data of television and radio broadcasts.
BACKGROUND
[0002] Television and radio broadcasters broadcast a large number
of programs. The viewership rating of each program is the basis on
which the broadcasters charge the advertisers for airing an
advertisement during the programming. If a program attracts high
viewership, the charge of the advertisement increases accordingly.
Thus, accurate measurement of audience participation in a program
is important to both the broadcasters and the advertisers.
[0003] Television and radio broadcast are one-way communication
systems. This makes it is difficult to determine the number of
viewership of a particular program without a feedback channel.
Current methods of collecting the number of viewership of a
particular program generally adopt a sampling approach. Typically,
this involves dividing the audience population into classes and a
representative sample of each class is selected for surveying. To
keep the surveying costs manageable, the size of the representative
sample is kept small. At the same time, the class definition has to
be as broad as possible in order to include a large demography of
the audience population. For example, economic categorizations (in
terms of SEC-A through SEC-C) are primary drivers. While these
classes give broad contours of viewership of a particular channel
(e.g., the National Geographic channel), they are not able to
obtain data on viewership of an individual program, which is what
the viewers watch and hence are of interest to the
broadcasters.
[0004] An example of an existing solution to viewership survey is
by installing dedicated monitoring devices in selected homes (i.e.
selected representative sample). These monitoring devices are
typically single function devices and are costly to be distributed
for free to home owners. The main task of such monitoring devices
is to identify the program being tuned to (i.e. viewed or listened)
and record this data on a non-volatile memory. The data is
subsequently off-loaded for analysis through an on-line connection
or an off-line storage media such as portable hard-disk or optical
disc. The programs are either identified by special codes sent by
the broadcaster at the beginning of the programs, image-matching to
determine a specific channel, or using the electronic program guide
to compare with the tuned channel (in the case of digital
television). A problem associating with this approach is that the
broadcaster has to reverse calculate which program or advertisement
was broadcast at a certain time. Since this information is usually
not available to the independent data collection agency (due to the
huge amount of constantly changing data), the compiled data is
usually presented as viewership of a particular channel instead of
viewership of a particular program or viewership of a particular
advertisement, which is what the advertiser is most interested
in.
[0005] The above approaches do not provide a satisfactory result
accuracy as viewers tend to switch channels during the
advertisements (channel surfing). Therefore, it is desirous to
provide an alternative method and system for surveying viewership
of television programs or listenership of radio programs that
alleviates at least some of the foregoing limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the present invention are herein described,
purely by way of example, with reference to the accompanying
drawings, in which:
[0007] FIG. 1A illustrates the location of a vertical blanking
interval in a conventional broadcast television signal employed in
an embodiment of the present invention;
[0008] FIG. 1B illustrates the location of a horizontal blanking
interval in a conventional broadcast television signal employable
in an embodiment of the present invention;
[0009] FIG. 2A illustrates a system for providing a data-augmented
AV signal in accordance with an embodiment of the present
invention;
[0010] FIG. 2B illustrates a method of providing a data-augmented
AV signal in accordance with an embodiment of the present
invention;
[0011] FIG. 3A illustrates a system for processing a data-augmented
AV signal in accordance with an embodiment of the present
invention;
[0012] FIG. 3B illustrates a method of processing a data-augmented
AV signal in accordance with an embodiment of the present
invention;
[0013] FIG. 3C illustrates a radio system for processing a radio
data-augmented signal in accordance with an embodiment of the
present invention;
[0014] FIG. 4 illustrates a functional block diagram of a
supplementary content processor shown in FIG. 3A in accordance with
an embodiment of the present invention;
[0015] FIG. 5A illustrates a system for collecting viewership data
in accordance with an embodiment of the present invention;
[0016] FIG. 5B illustrates a method of collecting viewership data
in accordance with an embodiment of the present invention;
[0017] FIG. 6 illustrates a functional block diagram of a
supplementary decoder of FIG. 5A; and
[0018] FIG. 7 shows examples of viewership data according to an
embodiment of the present invention.
DETAILED DESCRIPTION
[0019] Methods and systems for collecting viewership or
listensership of broadcast programs are described hereinafter with
references to FIGS. 1-7. For clarity and convenience, the following
definitions are used herein:
[0020] The term "data-augmented AV signal" refers to an AV signal
of a television program content or an audio signal of a radio
program content (hereinafter generally referred to as AV signal)
which has "supplementary content" added to the AV signal. The
data-augmented AV signal has the format of the original television
or radio AV signal. Typically, the supplementary content is
inserted into "a non-program portion" of the AV signal while the
program content is carried in a program portion of the AV
signal.
[0021] The term "supplementary content" refers to information or
data relating to the program content of the AV signal of a
television or radio broadcast program. The information or data can
be, for example, mobile phone ring-tones, music, games, pictures,
video clips, sound bites, general information, and the like
audience desired information all of which are associated with or in
connection to the program content. The supplementary content is
able to be printed on a printer, reproduced or rendered on an
electronic device, or stored in a data storage device, in an
embodiment, substantially concurrently with the rendering of the
program content.
[0022] The description "non-program portion" refers to the portion
of the AV signal which is reserved for conveying information or
data other than the program content. Exemplary embodiments of the
non-program portion of the AV signal include the vertical blanking
interval (VBI) of an analog television signal or an equivalent
signal portion of digital television broadcast signal (referred to
as DVB-VBI and DVB-TXT in the Digital Video Broadcast (DVB)
Standard), as well as equivalents in digital radio broadcasting
(e.g. the programming associated data channel in a digital audio
broadcast signal).
[0023] The term "conventional broadcast receiver" refers to radio
and television receivers or sets which are primarily dedicated to
the function of receiving radio and television broadcasts,
respectively. A conventional broadcast receiver typically has a
demodulation circuit operable to extract program content from the
data-augmented AV signal which has the same format as the
conventional AV signal.
[0024] "Conventional radio receivers" within this definition
include digital audio radios as described below. Other digital and
analog receivers operable to extract program content from a radio
broadcast signal may be employed in alternative embodiments. As
used herein, the term "conventional television set" refers to
conventional analog television sets, such as those configured to
process television broadcast signals transmitted in NTSC format,
using, for example, North American Basic Teletext (NABTS), PAL and
SECAM broadcast formats, using, for example, the European Broadcast
Union (EBU) Teletext Standards. In a further embodiment, the term
"conventional television set" includes digital televisions
receivers, such as those operable to process HDTV broadcasts using,
for example, the Vertical Ancillary Data (VANC), and the like
standards. Notwithstanding specific references made herein, the
term "conventional television set" extends to television sets
primarily operable to receive and process broadcast signals,
regardless of when it is developed, which employ a non-program
portion of the AV signal onto which the supplementary content can
be inserted. Specifically excluded from "conventional broadcast
receivers" are systems, such as computers, which can be programmed
or otherwise modified to emulate the functionality of a commonly
known television or radio receiver. Such systems do not have as its
primary function to receive and process such broadcast signals, and
are not specifically dedicated to operate as broadcast receivers,
and accordingly are not within the scope of the present
disclosure.
[0025] The term "conventional" as used with regard to broadcast,
radio, or television receivers/sets refers to the primary
functionality of the broadcast receiving system as described, and
does not refer to the timing of when such a broadcast system was
developed or deployed, which may be at any time during the past,
present or future.
[0026] The term "viewership" refers to audience participation in a
broadcast program. When used in a general sense, it includes
audience of a television broadcast program or a radio broadcast
program depending on the context.
Television Data-Augmented AV Signal
[0027] As known in the art of analog television broadcasting,
program content of a television program is provided in the form of
an AV signal which includes a program portion and non-program
portion in each frame. The program portion is used for carrying
program content while the non-program portion is used for carrying
extra information or data such as the vertical and horizontal
traces information. In the television broadcast standard, the
non-program portion of the AV signal is typically the vertical
blanking interval (VBI) found in each frame of the AV signal.
[0028] More recently, a variety of digital video broadcast (DVB)
standards are also used for broadcasting programs via satellite
(DVB-S), cable (DVB-C), terrestrial (DVB-T), or via handheld and
mobile terminals (DVB-H). Similar to the VBI in the analog AV
signals, DVB broadcast signals also allow the simulcasting of
supplementary content or data through DVB-TXT or DVB-VBI. When a
digital broadcasting system is employed, the DVB-TXT/VBI is used to
deliver the supplementary content as described in the foregoing.
For convenience, the description "vertical blanking interval"
refers to the vertical blanking interval (VBI) of the analog
broadcast television signal, as well as the equivalent non-program
portion of the digital broadcast television signals.
[0029] FIG. 1A illustrates the location of a VBI in a conventional
television broadcast signal employed in the embodiments. A standard
television signal consists of 625 horizontal lines (575 in North
America) which are divided into two frames of 312.5 lines each. The
VBI makes up the first 21 lines of each frame. Lines 1 to 9 are
typically used for timing setup and lines 10 to 21 are available
for carrying data 102.
[0030] Each VBI line is capable of transmitting 288 bits per
television frame (one packet). At 50 frames per second, 12 VBI
lines per frame translate into a raw data rate transmission of
about 144 Kbits per second. However, ensuring data integrity
requires forward error correction and this reduces the throughput
to about 70 Kbits per second. This throughput is better than those
provided by asynchronous telephone lines which have a throughput of
19.2 Kbits per second. The error rate after error correction is
1.0e-5 and this compares favorably with telephone network based
data transmission technologies.
[0031] FIG. 1B illustrates the location of a horizontal blanking
interval (HBI) in an analog television AV signal 100 which may also
be employed in the embodiments instead of the VBI. Data 102 which
is inserted into the horizontal blanking portion 104 is not
displayed on the television screen along with the program content,
as the television tuner is operable to process only the program
content embedded in the other portions of the television AV signal
100. Accordingly, references made to VBI herein also extend to
HBI.
[0032] In a teletext system, a separate channel of information is
formed by inserting various types of information, such as news,
sports, advertisements, and so on, in the VBI of the television AV
signal 100. Typically, the various types of information do not have
any correlation with the particular program content of the
television AV signal 100. In an embodiment, the VBI is utilized to
transport supplementary content specific to the program content of
the particular television AV signal 100. In a further embodiment,
the supplementary content inserted in a particular VBI represents a
supplementary content associating with the program content embedded
in adjacent program portion of the AV signal. In this way, each
program segment may have a different supplementary content
associated therewith and the supplementary content can be accessed
substantially concurrently with the rendering of the program
content segment at the conventional television set.
[0033] An embodiment of a system 210 and corresponding method 250
for providing data-augmented AV signals are respectively
illustrated In FIGS. 2A and 2B. Referring first to the system 210
illustrated in FIG. 2A, the system 210 includes a content server
212, an inserter 220, an RF module 224, and a transmitter 226,
which may include a satellite transmitter 226a, a cable television
transmitter 226b, or a transmitting tower 226c. These transmitting
means are only exemplary, and other transmitter embodiments will be
apparent to those skilled in the art.
[0034] The content server 212 is operable to provide supplementary
content 214 which is associated solely with a program content
conveyed in an AV signal 216 provided to the inserter 220. The
supplementary content 214 may further include information
concerning the program content, such as additional facts, figures
or other data, contact information such as a telephone number,
physical or email addresses, and the like information which is
specific to the program content of the a particular broadcast
program. Further, identifying information such as the version
number, size, copyright/digital-right status, author and language
of the supplementary content file may be included. Additionally,
program-specific advertiser or sponsor information may be included
in the supplementary content 214. For example, information such as
a list of manufacturers who provide cooking equipment shown in a
cooking program.
[0035] In another embodiment, the supplementary content 214 may
include interactive information which is designed to create an
interactive session with the television viewers. Such information
may include viewer queries which poses questions regarding the
content of the broadcast program, and which invites a response
thereto. Those skilled in the art will appreciate that other types
of supplementary content may be included.
[0036] The supplementary content 214 may be parsed into two or more
segments with each segment corresponding to a different segment of
the program content as conveyed in the AV signal 216. For example,
a cooking show may describe the processes of preparing several
different dishes. The supplementary content 214 may accordingly
include different content segments which include details regarding
recipes, recommended cooking times, and so on for the different
dishes. The content segments are accordingly sequenced so that the
supplementary content conveyed therein is synchronized with the
corresponding segments of the program content received by the
inserter 220. This process may be facilitated by the use of a
synchronization signal 218 communicating between the content server
212 and the inserter 220.
[0037] In an embodiment, the supplementary content 214 is organized
into a structured file or document, such as an extensible markup
language (XML) document. As such, the supplementary content 214 may
includes meta-data which is tagged using known or broadcast
industry adopted tags and fields. For example, identification of an
advertiser or sponsor associated with one or more segments of the
supplementary content may be identified using a meta-data tag
"Sponsor ID". Other meta-data tags corresponding to additional
information may also be used. For example, meta-data tag "Lang ID"
may be used to identify the language of the supplementary content,
"Date ID" to identify the composition date of the supplementary
content, "DRM ID" to identify digital rights management
information, "Exp ID" to identify an expiration date of the
supplementary content, and "Enc ID" to identify encryption
information applied to the supplementary content. The aforesaid
tags represent only a small sample of the possible meta-data tags
and types of information which can be conveyed, and other meta-data
tags may be used alternatively to or in addition thereto in other
embodiments.
[0038] Furthermore, the structured document may be linked (i.e.,
associated) with the program, either as one complete document which
contains one or more segments of the supplementary content, or as a
document having only a single segment of the supplementary content.
In the latter case, two or more such documents are used to compose
the entire stream of supplementary content 214 with each document
is linked to a corresponding segment of the program content. The
supplementary content 214, in this exemplary embodiment, includes
both the supplementary content associating with the program content
and identifying information (e.g., "Sponsor ID") in XML meta-data
file.
[0039] The following is an example of a structured document having
a file extension ".pcm":
TABLE-US-00001 <?XML V = "1.0"?> <ContentType>
<DocumentTitle>Test3</DocumentTitle>
<DocumentSize>221</DocumentSize>
<Akey>0001</Akey> <Document>
<language>en-us</language>
<PageId>1</PageId> <PageSize>221</PageSize>
<Description> <![CDATA[_%-12345X@PJL ENTER LANGUAGE=MIME
Content-Type: application/vnd.pwg-multiplexed;
type=application/vnd.pwg-xhtml-print+xml CHK 1 379 LAST
Content-Type: application/vnd.pwg-xhtml-print+xml Content-Location:
test2.htm <?xml version= "1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//PWG//DTD XHTML-Print 1.0//EN"
"http://www.xhtml-print.org/xhtml-print/xhtml- print10.dtd">
<html xmlns= "http://www.w3.org/1999/xhtml" > <head>
<title>test</title> </head> <body>
abcdefghijklmnopqrstuvwxyz </body> </html> CHK 0 0 LAST
_%-12345X]]> </Description> </Document>
[0040] This structured document (pcm file) is inserted into the VBI
lines by the inserter 220. The pcm file consists of two portions, a
meta-data portion and a data portion of the supplementary content.
In this exemplary pcm file, the data portion is enclosed by the
begin tag "<![CDATA" and end tag "]]>" with the rest being
the meta-data portion as further described herein.
[0041] Tag 1: <?XML V="1.0"?>
Tag 2: <ContentType>
[0042] These two tags form the mandatory beginning of the pcm file.
Tag 1 is used to indicate the beginning of the pcm file. Tag 2
indicates the type of content being conveyed, for example, a text
message, a sound bite, a video clip, or a combination thereof.
[0043] Tag 3: <DocumentTitle>Test3</DocumentTitle>
Every pcm file has a unique document title. The value of tag 3 is
used to distinguish one document from another during
broadcasting.
[0044] Tag 4: <DocumentSize>221</DocumentSize>
The value of tag 4 indicates the size of the data portion in bytes
in hexadecimal. This is not the size of the pcm file. In this
example, the data portion is printable and is presented in ASCII
text. It is also possible to use other formats such as postscript,
pdf, and the like document formats. The data portion can also be in
the form of binary data and non-printables.
[0045] Tag 5: <Akey>0001</Akey>
"Akey", in this example, refers to access key. The supplementary
content processor (such as the one shown in FIGS. 3A and 4) decodes
pcm file only when the value of tag 5 is a known or recognized
value. Thus, for pcm files that are meant for general access by the
public, the "Akey" value would be one which is assigned as such,
for example, "0001" as in this example.
[0046] Tag 6: <Document>
Tag 7: <language>en-us</language> Tag 6 indicates the
beginning of the details of the data portion. Tag 7 indicates the
language of the data portion (printable in this example). This
information is displayable on the screen of the television or the
display of the supplementary content processor.
[0047] Tag 8: <PageId>1</PageId>
Tag 9: <PageSize>221</PageSize>
[0048] The value of tag 8 indicates the page number. The value of
tag 9 indicates the size of the data portion of the page in
consideration. In this example, the size of the document and the
page is the same as there is only one page. In multiple page
documents, the size of the page would be smaller than the size of
the document.
[0049] Tag 10: <Description>, Tag 11: </Description>,
and Tag 12: </Document>
[0050] Tags 10 and 11 enclose the data portion. Tag 12 indicates
the end of the document details.
[0051] Referring back to FIG. 2A, the inserter 220 adds application
level forward error correction (FEC) to the supplementary content
214 and thereafter embeds the treated supplementary content 214 in
the non-program portion (i.e. VBI in the case of a television AV
signal) of the AV signal 216. The output from the inserter 220 is a
data-augmented AV signal 222 which is fed to the RF module 224. The
RF module 224 channel codes the data-augmented AV signal 222 before
converting it to an intermediate frequency and finally to an RF
broadcast signal for broadcasting. The RF broadcast signal is
broadcast using the transmitter 226 via one of the transmitting
means described in the foregoing.
[0052] In DVB standards, the data-augmented AV signal 222 is
broadcast in MPEG2 and the like digital formats. Thus, an encoder
(not shown) is provided to converted the data-augmented AV signal
222 output from the inserter 220 into an MPEG2 stream before
feeding the MPEG2 stream to the RF module 224 for further signal
conditioning.
[0053] Referring to FIG. 2B in which the corresponding method 250
of providing the data-augmented AV signal is illustrated. Initially
at step 252, the inserter 220 receives streams of AV signal
(containing a program content) 216 of a broadcast program. In one
embodiment, the program content typically includes ready produced
audio/video of the broadcast program and is provided along with
supplementary content identifying information, sponsor/advertiser
information, or other program related contents. In another
embodiment, however, such as live televised sports programs, the
program content is produced in real-time. Thus, the corresponding
supplementary content 214 (for example, the batting average of a
currently displayed baseball player at-bat which may be prepared
beforehand and stored in the content server 212), is supplied to
the inserter 220 synchronously with the live program content.
[0054] In step 254, the inserter 220 receives the supplementary
content 214 associating with the program content from the content
server 212. Subsequently in step 256 (also referring to FIG. 2A),
the supplementary content 214 is combined with or inserted into the
VBI of the AV signal 216 to provide the data-augmented AV signal
222. Additional processes may be used to complement the combining
processes at the inserter 220. For example, a forward error
correcting algorithm may be applied to the supplementary content
214 to improve transmission reliability. It is apparent that other
coding algorithms may be used in alternative embodiments.
[0055] In an embodiment, the provision of the supplementary content
214 can be synchronized with the appropriate program content
segment using the synchronization signal 218. Thus, the combining
process involves synchronizing segments of the supplementary
content 214 with the vertical blanking intervals of the AV signal
216 portions which carry the corresponding segments of the program
content.
[0056] The data-augmented AV signal 222 retains the signal waveform
of the original television AV signal 216 and can therefore be
processed by a television set in the conventional manner. In step
258 (also referring to FIG. 2A), the data-augmented AV signal 222
is provided to the RF module 224 for channel coding and modulation
with a carrier signal to provide an RF broadcast signal.
Subsequently, the RF broadcast signal is broadcast to receivers
using the transmitter 226.
[0057] An embodiment of a system 320 and corresponding method 350
for processing data-augmented AV signals are respectively
illustrated in FIGS. 3A and 3B. Referring first to the system 320
illustrated in FIG. 3A, the system 320 includes a receiving means
321 (a, b, c), a conventional television set 323, a supplementary
content processor 325, a content output means 327 (a, b), and an
optional a remote controller unit 328. Exemplary receiving means
includes a satellite receiver 321a, a set top box 321b, and a
television aerial 321c, each of which is adapted to receive RF
broadcast signal 322 which can be processed by the convention
television set 323 in the conventional manner. The television set
323 has electronic circuits to perform the reverse processes that
take place at the broadcasting end. The television set 323
demodulates the RF broadcast signal 322 to provide a data-augmented
AV signal (i.e. base-band signal) 324 which contains the program
content and the supplementary content.
[0058] The conventional television set 323 then renders the program
content on the television screen in the conventional manner. At the
same time, the data-augmented AV signal 324 is output to the
supplementary content processor 325, for example, via a video
output port of the conventional television set 323, where the
supplementary content is extracted therefrom.
[0059] The supplementary content processor 325 (hereinafter also
referred to as Supplementary Decoder) further processes the
extracted supplementary content to provide supplementary documents
or data 326 which are associated with the program content being
rendered on the conventional television set 323. Subsequently, the
supplementary data 326 can be output to a printer 327a for hardcopy
printout or can be stored in a data storage device 327b. The output
device 327 can also include other electronic devices such as mobile
phones, PCs, and PDAs.
[0060] In an embodiment, the remote controller unit 328 (the
functionality of which may be incorporated into a remote controller
unit of the conventional television set 323) can be used to control
the supplementary data downloading process at the supplementary
content processor 325. In an embodiment, the remote controller unit
328 is operable to instruct the supplementary content processor 325
to process the data-augmented AV signal 324 whereby the
supplementary content 324 corresponding to the currently viewed
program content is extracted and assembled to provide the
supplementary documents or data 326 which are subsequently
delivered to one or more of the output devices 327. In this manner,
the viewer can download supplementary content concurrently with
little or no disruption to the program viewing experience.
[0061] A method 350 of processing a data-augmented AV signal using
the system 320 of FIG. 3A is shown in FIG. 3B. Initially at step
352, the RF broadcast signal 322 is received (or recovered by the
receiving means 321). The RF broadcast signal 322 is in the format
of an original television broadcast signal and thus, can be
processed by the conventional television set 323 in the
conventional manner. The RF broadcast signal 322 contains the
data-augmented AV signal. In step 354, a demodulating circuit (not
shown) of the television set 323 is used to demodulate the RF
broadcast signal 322 (in the conventional manner) to provide a
base-band signal (i.e. the data-augmented AV signal 324) which
contains the program content and the supplementary content. The
program content is subsequently rendered on the television screen
in the conventional manner in step 356. At substantially the same
time, the data-augmented AV signal 324 can be output to the
supplementary content processor 325 for extracting and processing
the supplementary content in step 358.
[0062] The supplementary content processor 325 is operable to
extract the supplementary content from the data-augmented AV signal
and assembles the supplementary content into one or more printable
supplement documents or data 326. Further details of the
supplementary content processor 325 are described below with
reference to FIG. 4. The supplementary documents or data 326 are
delivered to output devices 327, which in two exemplary embodiments
include a printer 327a and a data storage device 327b in step 360.
It should be noted that other output devices may be used
alternatively or in addition thereto. Connection between the
supplementary content processor 325 and the output devices 327 may
be realized through various connection means, such as USB, IEE1394,
SCSI, parallel connections, wireless connections (e.g. Bluetooth,
WiFi), and the like communication means.
Radio Data-Augmented Signal
[0063] The system 210 and method 250 of FIGS. 2A and 2B can also be
used to provide and process radio signals augmented with data. As
an example, a digital audio broadcasting (DAB) system employs a
non-program audio signal component, commonly known as a program
associated data (PAD) channel, which can be used as the vehicle for
transporting the supplementary content. In such an embodiment, the
system 210 and corresponding method 250 can be used in
substantially the same manner, as described in the foregoing, for
receiving and processing a DAB broadcast signal of a DAB program
and supplementary content associating with the DAB program. The
supplementary content is provided by the content server 212. The
inserter 220 which is adapted for processing the DAB broadcast
signals is used to insert the supplementary content into the PAD
channel of the DAB signal, thereby forming a (DAB) radio
data-augmented signal. The radio data-augmented signal is
subsequently converted into a radio broadcast signal for
broadcasting via conventional transmitting means, exemplary
embodiments include satellite, cable, and tower transmitters. The
specific modulation process is a known art and is governed by the
DAB broadcasting standards.
[0064] Likewise, similar system and method to those of FIGS. 3A and
3B may be used for receiving and processing the radio
data-augmented signal. In an exemplary embodiment, a radio system
380 for receiving and processing the radio broadcast signal of the
aforementioned DAB is shown in FIG. 3C. The radio system 380
includes a conventional radio receiver 382 for receiving the radio
broadcast signal. Additionally, the conventional radio receiver 382
includes a demodulator or other such circuitries operable to
demodulate the radio broadcast signal to provide a radio base-band
signal (i.e. the radio data-augmented signal) containing the DAB
program and supplementary content. The radio system 380 further
includes a supplementary content processor 384 for receiving the
base-band signal and extracting the supplementary content
therefrom. The supplementary content is then assembled to provide
one or more supplement documents or data, which, for instance, by
using a remote controller unit 386, can be delivered to an output
device 390. The output device 390 can be a printer, data storage
device, PDA, PC, and the like electronic devices.
[0065] FIG. 4 illustrates a functional block diagram of a
supplementary content processor 400 (such as the supplementary
content processor 325 shown in FIG. 3A) that includes a data
extractor 421, an optional forward error correction (FEC) decoder
423, a document structure decoder 425, an application suite 427,
and associated application drivers 429. During operation, streams
of base-band signal 402 containing the supplementary content is
provided to the supplementary content processor 400. The data
extractor 421 extracts embedded supplementary content, for examples
applets or programming, from the base-band signal 402. Additional
operations within the data extractor 421 may include parsing the
supplementary content into segments, if this format is needed or
the recovered supplementary content is not so arranged.
[0066] Once the supplementary content is extracted from the
base-band signal 402, the supplementary content is put through the
FEC decoder 423 to correct any errors introduced during
broadcasting. The output from the FEC decoder 423 is subsequently
fed to the document structure decoder 425.
[0067] In an embodiment, the supplementary content (which may
include more than one segment, as described above) Is recovered in
the form of structured data such as XML-formatted data. In such an
embodiment, the document structure decoder 425 is employed to
decode the meta-data, or other such similar data used in
alternative structured document. The decoded data is provided to
the application suite 427 which further assembles the decoded data
into the desired format (i.e. data 404) for a particular
application. The application drivers 429 are operable to interface
with a particular output device 327, and may be incorporated within
the application suite 427 in an alternative embodiment. The
appropriately formatted data 404, referred to in the foregoing FIG.
3A as supplementary documents or data 326, is subsequently provided
to one or more of the output devices 327.
[0068] The supplementary content processor 400 may further include
a remote controller interface module (not shown) to which various
command signals can be issued for instructing the supplementary
content processor 400 to perform one, some, or all of the
aforementioned supplementary content processor functions. As an
example, the supplementary content processor 400 continually
processes streams of supplementary content segments as described in
relation to the content server 212 of FIG. 2A. Each supplementary
content segment includes supplementary content corresponding to,
and synchronized with, a segment of the program content. When the
viewer is presented with a topic that the viewer desires to acquire
more information on, the viewer actuates the appropriate buttons on
the remote controller unit. The signal produced thereby in turn
activates the supplementary content processor 400 to generate the
supplementary document or data 404 for output to one or more of the
output devices. In this manner, the corresponding content segment
can be downloaded (as a printed or stored electronic document, for
instance) conveniently with minimal disturbance to the viewing
experience.
[0069] In many broadcasting situations, whether radio or
television, it is desirable to obtain data on viewership of
broadcast programs (including advertisements). In an embodiment,
the systems and methods described in the foregoing can be used for
collecting such data as described hereinafter with reference to
FIGS. 5-7. FIGS. 5A and 5B respectively illustrate a system 510 and
method 550 for collecting viewership data using broadcast programs
augmented with multiple types of supplementary content for
identifying broadcast programs and monitoring the viewership
thereof.
[0070] The system 510 as shown in FIG. 5A according to an
embodiment includes a data-augmented broadcast signal providing
system 512, a data-augmented broadcast signal processing system
516, and a viewership data collection entity 526. The viewership
data collection entity 526 can be a broadcaster, rating agency,
advertiser, research center, and the like entities interested in
the viewership data. In this exemplary embodiment, the
data-augmented broadcast signal providing system 512 and the
data-augmented broadcast signal processing system 516 are similar
in makeup to the respective systems shown in FIGS. 2A and 3A (and
3C) as described in the foregoing. Information or data associating
with a broadcast program is provided as supplementary content to
the data-augmented broadcast signal providing system 512.
[0071] The supplementary content is combined with the broadcast
program to provide a data-augmented AV signal which is subsequently
modulated with a carrier signal to provide a transmit signal 514
for broadcasting in the conventional manner (i.e. television or
radio broadcasting). At the receiving end, the transmit signal 514
is received by the data-augmented broadcast signal processing
system 516. The data-augmented broadcast signal processing system
516 demodulates the transmit signal 514 to provide a base-band
signal (i.e. the data-augmented AV signal) containing the program
content and the supplementary content. The program content is
rendered and at substantially the same time, the base-band signal
is output to a supplementary decoder 518 where the supplementary
content is extracted and further processed.
[0072] In this embodiment, the supplementary decoder 518 is similar
in makeup to the supplementary content processor 400 (as shown in
FIG. 4) and further includes a program monitoring application 602
as shown in FIG. 6. The program monitoring application 602 is
coupled to the document structure decoder 425. One of the functions
of the program monitoring application 602 is to detect
identification tags of broadcast programs. As described in the
foregoing, supplementary contents associating with broadcast
programs are organized as structured documents, each having a
meta-data portion and a data portion. The meta-data portion
includes at least one tag for identifying the broadcast program.
For finer tracking details, tags identifying episodes or sections
of the broadcast program can also be included. In the same manner,
tags identifying specific advertisements and sponsors can also be
included in the structured document for monitoring purposes.
[0073] The program monitoring application 602 scans the meta-data
and identifies tags relating to the broadcast programs or other
tags which the program monitoring application 602 is programmed to
monitor. The identities of the tags are subsequently recorded and
stored in a memory (not shown) of the supplementary decoder 518
along with the time the tags are detected. This information
constitutes viewership data and it can be tallied or organized in a
table format or other easily understood formats. The viewership
data can then be sent to the viewership data collection entity 526
in a number of ways. In an embodiment, the viewership data can be
sent to the viewership data collection entity 526 via an electronic
device 522. The electronic device 522 is linked to the
supplementary decoder 518 via a communication link 520. The
electronic device 522 can be a printer, mobile phone, PDA, PC, and
the like utility devices. Accordingly, the communication link 520
can be a wired connection such as USB, Firewire, serial, and
parallel connections, or wireless connection such as Bluetooth,
WiFi, infra-red, and the like electronic communication means. The
electronic device 522 is registered with the supplementary decoder
518 in order to receive the viewership data. However, not all
electronic devices registered with the supplementary decoder 518
need to receive the viewership data. The supplementary decoder 518
can be provided with a user option to select which of the
electronic devices registered therewith should receive the
viewership data and only sends the same to the electronic device
specified to receive such data. The user option can be presented on
a display of the receiver (e.g. television screen) or a display of
the supplementary decoder 518.
[0074] Using the electronic device 522, the viewership data can be
provided to the viewership data collection entity 526 via a
communication link 524. The electronic device 522 may also be
provided with an application for enabling the user to edit the
viewership data before sending the same to the viewership data
collection entity 526. The communication link 524 is an existing
communication infrastructure of the electronic device 522 such as a
cellular network, Internet connection, land line, fax line, and the
like communication links depending on the type of electronic device
522 in use. Thus, the electronic device 522 and communication link
524 serve as a feedback channel for the mono-direction link between
a broadcast station and a conventional receiver. For example, if
the electronic device 522 is a mobile phone, the viewership data is
returned to the viewership data collection entity 526 via the
mobile phone cellular network. If the electronic device 522 is a
PC, the viewership data can be sent to the viewership data
collection entity 526 via an Internet connection using email or any
other acceptable file transfer protocols. Alternatively, if the
electronic device 522 is a printer, the viewership data printed out
by the printer can be faxed to the viewership data collection
entity 526 using a fax machine connecting to a telephone line.
[0075] In an alternative embodiment, the viewership data can be
sent to the viewership data collection entity 526 via a direct
communication link 525 as shown in FIG. 5A. The communication link
525 can be a dedicated cable linking the supplementary decoder 518
to the viewership data collection entity 526 or an Internet
connection. Thus, the supplementary decoder 518 is integrated with
or linked to a modem (not shown) to facilitate the data
communication.
[0076] In the foregoing embodiments, control can be given to the
audience to determine if and when the viewership data should be
released to the viewership data collection entity for privacy
reasons. This is achieved by providing the audience with an option
(e.g. by using a remote controller unit) to instruct the
supplementary decoder 518 to compile the viewership data and
specify the means for sending the viewership data. Furthermore, the
audience can be given the option to decide what information is to
be released. For example, the audience may only desire to release
viewership data of a specific channel but not all channels viewed
by the audience. Other options can also include only providing
viewing information on certain days of the week or times of the
day. Thus, the audience can decide whether or not to release
information on the viewing habit, for example, according to a
contractual agreement with the viewership data collection entity
526. Alternatively, the program monitoring application 602 can be
programmed to automatically compile the viewership data in a
pre-determined format and sends the same to the viewership data
collection entity 526 at a specified time.
[0077] The method 550 of collecting viewership data using broadcast
signals augmented with multiple types of supplementary content for
identifying broadcast programs and monitoring the viewership
thereof is shown in FIG. 5B. The method 550 includes receiving an
AV signal of a broadcast program in step 552 and supplementary
content associating with the broadcast program in step 554. In an
embodiment, the broadcast program is a television broadcast
program. In another embodiment, the broadcast program is a radio
broadcast program. The broadcast program can be any information
such as movies, news, sports, current affairs, and the like
information typically broadcast. The supplementary content can be
any information associating with the broadcast program which the
audience members may be interested in. The supplementary content
can be provided in the form of a XML-type document (structured
document) which includes a meta-data portion and a data portion as
described in the foregoing. In a multiple supplementary contents
environment, the different supplementary contents are distinguished
by providing identifying information in the meta-data portion. For
example, in an embodiment where monitoring broadcast program
viewing by audience members is desired, the supplementary content
includes a tag, such as "Program=FRIENDS", for identifying the
broadcast program in the meta-data portion. Further, information
relating to the broadcast program segments or episodes (e.g. a
summary or still frame shot from the episode) can be provided in
the data portion of the supplementary content. Therefore, multiple
supplementary contents can be provided and received in step 554,
wherein each supplementary content corresponds to a segment or
episode of the broadcast program. The tags carried in each
supplementary content are small in size. As such, the tags can be
sent at a regular interval acting as a type of heart beat for
monitoring the viewing of the broadcast program. Furthermore, the
tags contained in each sequential supplementary content can be in a
sequence. In this way, any missing tags at the viewing side
indicate that portions of the broadcast program as indicated by the
missing tags are not viewed.
[0078] The supplementary content is combined with the non-program
portion (e.g. VBI) of the AV signal to provide a data-augmented AV
signal in step 556. The data-augmented AV signal is subsequently
modulated with a carrier (broadcast) signal to provide a transmit
signal for broadcasting to conventional receivers in step 558. The
data-augmented AV signal has the same format as the original AV
signal. Thus, the data-augmented AV signal can be treated,
broadcast and received in the same manner as a conventional
television or radio broadcast signal.
[0079] In an embodiment, the supplementary content is inserted into
the VBI of the AV signal as it is received in step 556. The
supplementary content is combined with a specific non-program
portion segment of the AV signal to closely reside with the
specific program-portion segment of the broadcast program. For
example, if a supplementary content is closely related to a segment
of the broadcast program, the supplementary content is combined
with the non-program portion adjacent to the program portion of the
related segment of the broadcast program. Thus, there is
synchronization between the segments of the broadcast program with
the supplementary contents. In this way, at the receiver end, the
audience is presented with the option to download the supplementary
content at the appropriate time when the audience is most
influenced by the program content segment.
[0080] At the receiver end, the transmit signal is received by a
conventional receiver. The conventional receiver processes the
transmit signal in the conventional manner. Typically, step 560
includes demodulating the transmit signal to provide a base-band
signal (i.e. the data-augmented AV signal) which contains the
program content and the supplementary content. In the case where
the transmit signal is a radio signal, the conventional receiver is
a radio receiver and it retrieves the program content from the
base-band signal and presents the program content to the listener
in audio form. In the case where the transmit signal is a
television signal, the conventional receiver is a television
receiver and it renders the program content on the television
screen. The act of rendering the program content is performed in
step 562, a process well known in the art.
[0081] At substantially the same time of rendering the program
content, the base-band signal is output to a supplementary decoder
in step 564. The supplementary decoder retrieves the supplementary
content from the base-band signal as described in the foregoing
with reference to FIGS. 3A, 4, and 6. In step 564, the
supplementary content is further processed by the program
monitoring application 602 as described in the foregoing with
reference to FIG. 6. The program monitor application 602 scans the
meta-data portion of the supplementary content for a tag
identifying the broadcast program. Upon successfully detecting the
tag, a record (viewership data) is kept in a memory module (not
shown) of the supplementary decoder along with the time of the tags
detection. The record can be arranged in a pre-determined format
such as a table or graphical representation. FIG. 7 shows examples
of the record layout. Table 702 shows a summary of the programs
viewed for a given day according to channels. Table 710 shows a
summary of the programs viewed over a one week period. Table 710
also shows two blocked portions 712 and 714, where the audience
chooses to remove viewing information during these periods. Other
information in the data portion (e.g. a summary of the program) of
the supplementary content can also be included in the record (not
shown). Furthermore, the audience can also add extra data 716 into
the record. Such extra data 716 can include personal information
such as age group, gender, family size, income brackets, ethnic
group, location/geography, and the like information.
[0082] In an embodiment, the program monitor application 602 can be
programmed to automatically and directly send the record to a
viewership data collection entity upon detecting the end of the
program broadcast. Thus, in step 566, the record is sent to and
received by the viewership data collection entity. Further, prior
to sending the record to the viewership data collection entity, the
supplementary decoder can be provided with an editing application
and an option can be given to the audience to edit the record using
the editing application. For example, to block out viewing record
periods (712 and 714) as shown in table 710 of FIG. 7. In this
embodiment, the supplementary decoder is provided with a direct
communication link with the viewership data collection entity. In
another embodiment, the record can be sent to the viewership data
collection entity via an electronic device in step 568. The
electronic device can be a printer where the record can be printed
out in a hardcopy. Subsequently, the printed record can be sent to
the viewership data collection entity using a surface mail or fax
machine. Alternatively, the electronic device can be a mobile
phone, PC, PDA and the like devices. Therefore, the electronic
device can be provided with an editing application so that the
audience can further edit the record. In this embodiment, the
record is sent to the viewership data collection entity using
existing communication infrastructures of the electronic
device.
[0083] In the foregoing embodiments, the sending of the record can
be triggered anytime by the audience. This is achieved by sending
an instruction to the supplementary decoder using a remote
controller unit, controlling buttons of the supplementary decoder,
or by using the electronic device to issue the sending
instruction.
[0084] In an exemplary embodiment, a viewership data collection
entity is interested in surveying the viewing habit of television
audience. Using the system 510 and method 550 described in the
foregoing, such information can be readily collected. At the
broadcasting side, broadcast programs are provided with tags
identifying the broadcast programs. The tags can include tags
identifying the broadcast channels, names of the broadcast programs
as well as episodes of the broadcast programs. These tags can be
provided as supplementary contents associating with the broadcast
programs. The supplementary contents are provided in the form of
structured documents, each containing a meta-data portion for
containing the tags and a data portion for containing other data or
information relating to the broadcast program. The broadcast
program and associated supplementary contents are combined and then
modulated with a carrier signal to provide a transmit signal for
broadcasting to television receivers.
[0085] At the receiver side, the transmit signal is received and
demodulated to provide a data-augmented AV signal containing the
program content and supplementary contents. The program content is
rendered on the television screen. At substantially the same time,
the supplementary contents are recovered by a supplementary decoder
which is coupled to the television receiver. The supplementary
decoder scans the meta-data in the supplementary contents and makes
a record of the identities of the tags detected. The supplementary
decoder also records the time the tags are detected. This
information is compiled in an easy to understand predetermined
format, such as a table or a graphical representation, and
collectively provide information on the viewing habits of the
audience. That is, the record keeps track of the time of the
viewing as well as the channels and programs viewed by the
audience.
[0086] The record can be forwarded to the viewership data
collection entity in a number of ways. One way is to send the
record in electronic form to the viewership data collection entity
directly from the supplementary decoder. Thus, the supplementary
decoder is provided with a communication link for transferring the
record to the viewership data collection entity. Examples of the
communication link include a cable link and an Internet connection.
Another way is to send the record to a printer connected to the
supplementary decoder. The printed record can then be sent to the
viewership data collection entity either by surface mail or by
using a fax machine. In yet another way, the record can be sent to
an electronic device, such as a mobile phone, PC, or PDA, which
subsequently sends the record to the viewership data collection
entity using the communication infrastructure of the electronic
device. Examples of the communication infrastructure include
cellular network in the case of a mobile phone and Internet
connection in the case of a PC or PDA. Further, before sending the
record, the audience may be given an option to make changes to the
record. The audience may want to remove certain information from
the record such as viewing habit of a certain channel or during a
period of time.
[0087] As readily appreciated by those skilled in the art, the
described processes may be implemented in hardware, software,
firmware or a combination of these implementations as appropriate.
For example, the processes of modulating and broadcasting signals
may be carried out by hardware component modulators and transmitter
systems operable to modulate and broadcast signals at the desired
frequency and in the desired format. The described supplementary
content processor or supplementary decoder may employ a combination
of hardware front-end receiver components operable to additionally
demodulate and/or condition the received supplementary content, and
firmware/software operable to FEC decode the supplementary content
and to store/process the resultant data as well as the output
applications and device drivers. In addition, some or all of the
described processes may be implemented as computer readable
instruction code resident on a computer readable medium (removable
disk, volatile or non-volatile memory, embedded processors, etc.),
the instruction code operable to program a computer of other such
programmable device to carry out the intended functions.
[0088] The foregoing description is presented for purposes of
illustration and description. It is not intended to be exhaustive
or to limit the invention to the precise form disclosed, and
obviously many modifications and variations are possible in light
of the foregoing description. The described embodiments are chosen
in order to explain the principles of the invention and its
practical application to thereby enable others skilled in the art
to utilize the invention in various embodiments and with various
modifications as are suited to the particular use contemplated. It
is intended that the scope of the invention be defined by the
claims appended hereto.
* * * * *
References